E-book แนะนำผลงานทางวิชาการ

Characterization and properties
of Zn/Co zeolitic imidazolate
frameworks vs. ZIF-8 and ZIF-67

ผศ. ดร.สพุ จน พฒั นะศร� ภาควช� าวศ� วกรรมเคมี
0-2218-6890 [email protected]

ABSTRACT

A novel Zn/Co zeolitic imidazolate framework (ZIF) has been constructed by an
easy and straightforward room temperature technique. Several characterization
techniques such as SEM, TEM-EDX, single-crystal XRD and ICP have been applied to
confirm that the structure formed is a sodalite (SOD) cage type structure. The
Zn/o-ZIF possesses a high nano-crystallinity and porosity with a large surface area.
By tuning the amount of Co and Zn in the Zn/Co zeolitic imidazolate framework, the
physical and chemical properties have been improved compared with those of the
single metal frameworks (ZIF-8 and ZIF-67). Consequently, the Zn/Co-ZIF was
investigated for two different applications; gas adsorption (CO2, CH4 and N2) and
catalysis (CO2 conversion to cyclic carbonates) and the obtained results were
compared with the performance of previously reported single metal frameworks
(ZIF-8 and ZIF-67). Additionally, hydrolytic stability tests under ambient conditions
and immersed in water at 75 °C were performed and pointed out that Zn/Co-ZIF
exhibits a higher stability. Moreover, based on these results, the Zn/Co-ZIF
demonstrates better properties compared with ZIF-8 and ZIF-67.

FULL PAPER (LINK)

ดเู พิ่มเติมไดทวี่ ารสาร
Journal of Materials Chemistry A
ตพี มิ พป  2017 ฉบับท่ี 5 หนา 952-957

http://pubs.rsc.org/en/Content/ArticleLanding/2017/TA/C6TA07860E

หนว ยสอ่ื สารองคก ร [email protected]

Defect formation in metal – organic
frameworks initiated by the crystal
growth-rate and effect on catalytic
performance

ผศ. ดร.สพุ จน พฒั นะศร� ภาควช� าวศ� วกรรมเคมี
0-2218-6890 [email protected]

ABSTRACT

The defect formation in metal–organic frameworks (MOFs) initiated by the
crystal growth-rate of different synthesis procedures affects the structure,
morphology and other properties of MOFs such as particle shape, gas
adsorption capacity and specifically catalytic performance etc. Although the
design of defect structures and the defect structures itself are well known,
comparatively little is known regarding defect creation introduced by the
synthesis procedure (different from mixed-linker approach, the use of acid
modulators, post-synthetic treatment, etc.) and characterization of the
resulting naturally occurring abnormalities (defects) in the material.
Moreover, high performance of MOFs in various catalytic reactions can be
correlated to the higher amount of defect structures because defects can
possibly exhibit acid and / or basic properties. While studies of MOF
crystallinity confirmed that for a given type of MOF different synthesis
methods generate samples of similar crystal structures, their morphologies
are often different due to the differences in the crystallization rates
associated with these methods.

FULL PAPER (LINK)

ดเู พม่ิ เติมไดท วี่ ารสาร
Journal of Catalysis
ตพี มิ พป  2017 เดือนตลุ าคม ฉบับที่ 354 หนา 84-91

https://www.sciencedirect.com/science/article/pii/S002195171730297X

หนว ยสอ่ื สารองคก ร [email protected]

One-Step Synthesis of 2,5-Bis
(chloromethyl)-1,4-dioxane from
Epichlorohydrin Using ZIF-8, Taking
Advantage of Structural Defects

ผศ. ดร.สุพจน พฒั นะศร� ภาคว�ชาว�ศวกรรมเคมี
0-2218-6890 [email protected]

ABSTRACT

We demonstrate herein the ZIF-8-only-mediated catalysis of the
cyclodimerization of epichlorohydrin to 2,5-bis(chloromethyl)-1,4-
dioxane in the absence of co-catalyst and solvent. The easy handling
and economic aspects of ZIF-8, in addition to the one-step reaction to
produce the cyclodimer, make this catalyst attractive even for industry.
It has been clearly illustrated that the nature of the method used to
synthesize ZIF-8 affected the yields of the cyclodimers. Specifically, the
method employed to produce ZIF-8 directly influences the amount of
crystal structural defects, which in turn impacts their performance as
catalysts. To emphasize the role of defects, other physical properties,
such as surface area and particle size, were controlled during the
synthesis of the ZIF-8 catalysts. Remarkably, the amount of structural
defects was quantified by temperature program desorption analysis.

FULL PAPER (LINK)

ดูเพ่มิ เตมิ ไดท ี่วารสาร
European Journal of Inorganic Chemistry
ตพี มิ พป  2017 เดือนพฤศจิกายน ฉบบั ท่ี 2017 หนา 4947-4954
https://onlinelibrary.wiley.com/doi/abs/10.1002/ejic.201700673

หนว ยสอ่ื สารองคก ร [email protected]

Analysis of the Ca-looping
sorption-enhanced steam reforming
and solid oxide fuel cell integrated
process using bio-oil

ผศ. ดร.อมรชยั อาภรณว ช� านพ ภาควช� าวศ� วกรรมเคมี
0-2218-6999 [email protected]

ABSTRACT

Solid oxide fuel cell (SOFC) is a powerful technology for heat and power generation
that can be combined with many applications. This study presents a thermodynamic
analysis of the Ca-looping sorption-enhanced steam reforming (SESR) of bio-oil
integrated with an SOFC. Acetic acid is used as a model compound to represent a
bio-oil aqueous fraction. Useful heat from an SOFC is utilized in the regenerator
to improve the performance of the SOFC system. The effects of key parameters in
operating the Ca-looping sorption-enhanced steam reformer and SOFC are discussed.
The results indicate that Ca-looping SESR integrated with SOFC has a higher
performance than the conventional process. Increasing the SESR temperature, the
CaO/fuel ratio, the SOFC temperature, and the fuel utilization increases the electrical
efficiency, but it decreases with S/F ratio. Regarding an energy analysis, the regenerator
requires higher energy when it operates at a high steam and CaO/fuel ratio but lower
energy when it operates at high SESR temperatures. In addition, the system efficiency
of the SOFC integrated process decreases with SESR temperature and steam due to the
high amount of energy to feed and air preheating. Heat integration using the pinch
analysis method to certify the maximum heat recovery improves the system efficiency.

FULL PAPER (LINK)

ดเู พ่มิ เติมไดที่วารสาร
Energy Conversion and Management
ตพี มิ พป 2017 เดอื นกุมภาพันธ ฉบบั ที่ 134 หนา 156-166

https://www.sciencedirect.com/science/article/pii/S0196890416311116

หนว ยสอ่ื สารองคก ร [email protected]

Control structure design of a solid
oxide fuel cell and a molten
carbonate fuel cell integrated system:
Top-down analysis

ผศ. ดร.อมรชัย อาภรณว ช� านพ ภาควช� าวศ� วกรรมเคมี
0-2218-6999 [email protected]

ABSTRACT

The integrated system of a solid oxide fuel cell and molten carbonate fuel
cell theoretically has very good potential for power generation with carbon
dioxide utilization. However, the control strategy of such a system needs to be
considered for efficient operation. In this paper, a control structure design for
an integrated fuel cell system is performed based on economic optimization to
select manipulated variables, controlled variables and control configurations.
The objective (cost) function includes a carbon tax to get an optimal trade-off
between power generation and carbon dioxide emission, and constraints
include safe operation. This study focuses on the top-down economic analysis
which is the first part of the design procedure. Three actively constrained
regions as a function of the main disturbances, namely, the fuel and steam feed
rates, are identified; each region represents different sets of active constraints.
Under nominal operating conditions, the system operates in region I. However,
operating the fuel cell system in region I and II can use the same structure, but
in region III, a different control structure is required.

FULL PAPER (LINK)

ดเู พ่มิ เตมิ ไดที่วารสาร
Energy Conversion and Management
ตีพิมพป  2017 เดือนพฤศจกิ ายน ฉบบั ที่ 152 หนา 88-89
https://www.sciencedirect.com/science/article/pii/S0196890417308464

หนว ยสอ่ื สารองคก ร [email protected]

Cycle analysis of solid oxide fuel
cell-gas turbine hybrid systems
integrated ethanol steam reformer:
Energy management

ผศ. ดร.อมรชยั อาภรณว ช� านพ ภาควช� าวศ� วกรรมเคมี
0-2218-6999 [email protected]

ABSTRACT

A solid oxide fuel cell-gas turbine (SOFC-GT) hybrid system that uses such liquid
fuels as ethanol is attractive for distributed power generation for applications in
remote rural areas or as an auxiliary power unit. The SOFC system includes units
that require and generate heat; thus, its energy management is important
to improve its efficiency. In this study, a SOFC-GT integrated system with the
external steam reforming of ethanol to produce hydrogen for the SOFC is
proposed. Two SOFC-GT hybrid systems using a high-temperature heat exchanger
and cathode exhaust gas recirculation are considered under isothermal
conditions. The effects of key operating parameters, such as pressure, fuel use and
turbomachinery efficiency, on the SOFC-GT hybrid system performance are
discussed. The simulation results indicate that recycling the cathode exhaust gas
from the SOFC-GT system requires less fresh air from the compressor, to maintain
the SOFC stack temperature, and the heat recovered from the SOFC system
is sufficient to supply both the fuel processor and air pre-heater. In contrast,
an external heat is needed for the SOFC-GT system coupled to a recuperative heat
exchanger.

FULL PAPER (LINK)

ดูเพมิ่ เติมไดท ่วี ารสาร
Energy
ตีพิมพป  2017 เดอื นพฤษภาคม ฉบับที่ 127 หนา 743-755

https://www.sciencedirect.com/science/article/pii/S0360544217304899

หนว ยสอ่ื สารองคก ร [email protected]

Design and optimization of
dimethyl ether production from
crude glycerol in a reactive
distillation

ผศ. ดร.อมรชยั อาภรณว ช� านพ ภาควช� าวศ� วกรรมเคมี
0-2218-6999 [email protected]

ABSTRACT

Methanol in crude glycerol from biodiesel production is considered
to be a raw material for dimethyl ether production. In this work,
the production of dimethyl ether from the dehydration reaction of
methanol in a reactive distillation is studied. A model of the reactive
distillation is developed using a process simulator and used to analyze
its performance by considering both the methanol conversion and the
total annual cost. The effect of key operating parameters on conver-
sion of methanol is reported. The optimal process design is deter-
minedinterms of the minimization of total annual cost.

FULL PAPER (LINK)

ดูเพม่ิ เติมไดท ว่ี ารสาร
Chemical Engineering and Processing: Process Intensification
ตพี ิมพป  2017 เดอื นกรกฎาคม ฉบับที่ 117 หนา 80-88

https://www.sciencedirect.com/science/article/pii/S0255270117300326

หนว ยสอ่ื สารองคก ร [email protected]

Design of SOFC based oxyfuel
combustion systems with anode
recycling and steam recycling options

ผศ. ดร.อมรชยั อาภรณว ช� านพ ภาควช� าวศ� วกรรมเคมี
0-2218-6999 [email protected]

ABSTRACT

A solid oxide fuel cell (SOFC) based power plant incorporating an oxyfuel com-
bustion process to reduce carbon dioxide emissions is analyzed. The effects of key
parameters, such as the steam-to-carbon ratio, fuel utilization factor, and tempera-
ture, on the current density, voltage, heat production, and requirements of each
unit are investigated. In addition, the overall performance of the SOFC–oxyfuel
integrated systems with anode recycling and steam recycling are studied and com-
pared. The SOFC system with anode recycling provides better electrical efficiency
than that with steam recycling because of the high utilization of fuel in the SOFC
and the ability to integrate a fuel turbine. In the SOFC with steam recycling, a fuel
turbine cannot be implemented because there is insufficient heat for preheating
the inlet streams, which is primarily used to vaporize the recycling stream. The con-
ditions for SOFC–oxyfuel combustion in systems with anode or steam recycling
that provide the optimum electrical efficiency are also analyzed.

FULL PAPER (LINK)

ดูเพม่ิ เติมไดท วี่ ารสาร
Energy Conversion and Management
ตีพมิ พป  2017 เดือนพฤศจกิ ายน ฉบบั ที่ 151 หนา 723-736

https://www.sciencedirect.com/science/article/pii/S0196890417308348

หนว ยสอ่ื สารองคก ร [email protected]

Efficient heat allocation in the
two-step ethanol steam reforming
and solid oxide fuel cell integrated
process

ผศ. ดร.อมรชยั อาภรณว ช� านพ ภาควช� าวศ� วกรรมเคมี
0-2218-6999 [email protected]

ABSTRACT

To avoid a carbon formation in the ethanol steam reforming process from the
polymerization of ethylene, a two-step reforming of ethanol via a dehydrogenation
reaction and a steam reforming reaction for hydrogen production is proposed in this
work. The study of using a CaO sorbent for CO2 capture to enhance the hydrogen
production for solid oxide fuel cells is also carried out. Modeling of the two-step
ethanol steam reforming and solid oxide fuel cell integrated process based on a
thermodynamic approach is performed using a flowsheet simulator. The results show
that the presence of CaO in the two-step ethanol steam reforming process has several
advantages, such as having higher hydrogen yield, gaining additional heat, and
providing a higher power output at a relative low reforming temperature. However,
the exergy analysis indicates that this process has a higher total exergy destruction
compared to the process without CaO because of the high amount of heat needed in the
regenerator. Therefore, a heat allocation technique based on the first and second laws of
thermodynamics is used to identify the optimal operating condition. The results show
that when the reformer is operated at a temperature of 800 K and a steam-to-ethanol
ratio of one, the minimum total exergy destruction to power ratio can be achieved and
heat is also sufficient.

FULL PAPER (LINK)

ดเู พม่ิ เติมไดท่วี ารสาร
Energy
ตีพิมพป  2017 เดือนสิ งหาคม ฉบบั ท่ี 133 หนา 545-556

https://www.sciencedirect.com/science/article/pii/S0360544217309039

หนว ยสอ่ื สารองคก ร [email protected]

Exergy analysis of the biogas
sorption-enhanced chemical looping
reforming process integrated with
a high-temperature proton exchange
membrane fuel cell

ผศ. ดร.อมรชยั อาภรณว ช� านพ ภาควช� าวศ� วกรรมเคมี
0-2218-6999 [email protected]

ABSTRACT

A biogas sorption-enhanced chemical looping reforming process integrated with
a high-temperature proton exchange membrane fuel cell is analyzed. Modeling of
such an integrated process is performed by using a flowsheet simulator (Aspen plus).
The exergy analysis is performed to evaluate the energy utilization efficiency of each
unit and that of the integrated process. The effect of steam and nickel oxide to biogas
ratios on the exergetic performance of the stand-alone biogas sorption-enhanced
chemical looping reforming process is investigated. The total exergy destruction
increases as the steam or nickel oxide to biogas ratio increases. The main exergy
destruction is found at the air reactor. For the high-temperature proton exchange
membrane fuel cell, the main exergy destruction is found at the cathode. The total
exergy destruction increases when cell temperature increases, whereas the inverse
effect is found when the current density is considered as a key parameter. Regarding
the exergy efficiency, the results show opposite trend to the exergy destruction. The
heat integration analysis is performed to improve the exergetic performance. It is
found that the integrated process including the heat integration system can improve
the exergy destruction and exergy efficiency of 48% and 60%, respectively.

FULL PAPER (LINK)

ดเู พม่ิ เติมไดท ีว่ ารสาร
Energy Conversion and Management
ตีพิมพป 2017 เดอื นตุลาคม ฉบับท่ี 149 หนา 485-494

https://www.sciencedirect.com/science/article/pii/S0196890417306878

หนว ยสอ่ื สารองคก ร [email protected]

Techno-economic assessment of
extractive distillation for tert-butyl
alcohol recovery in fuel additive
production

ผศ. ดร.อมรชยั อาภรณว ช� านพ ภาควช� าวศ� วกรรมเคมี
0-2218-6999 [email protected]

ABSTRACT

Excess tert-butyl alcohol is generally used to promote the etherification
reaction for production of glycerol ether. However, the difficulty in recovering
this excess alcohol is caused by the presence of an azeotropic mixture of
tert-butyl alcohol and water, a by-product from the etherification. This work
proposes a recovery process of tert-butyl alcohol consisting of extractive
distillation and conventional distillation columns. Feasible organic and ionic
liquid solvents are firstly screened through such criteria as environmental
concern and thermodynamic insight. Then, simulations of the extractive
and distillation system for tert-butyl alcohol recovery are performed based
on the suitable selected solvents, i.e., 3-octanone, hexyl acetate and 2-
heptanone. From the techno-economic assessment, hexyl acetate is the
most suitable solvent and the optimal configuration and operation of the
process are also presented. Regarding the environmental impact indicator,
hexyl acetate is also considered the most suitable solvent due to the lowest
requirement of solvent.

FULL PAPER (LINK)

ดูเพ่ิมเติมไดทว่ี ารสาร
Chemical Engineering and Processing: Process Intensification
ตพี มิ พป 2017 เดอื นธนั วาคม ฉบบั ท่ี 122 หนา 161-171
https://www.sciencedirect.com/science/article/pii/S0255270117304816

หนว ยสอ่ื สารองคก ร [email protected]

Co-processing of palm fatty acid
distillate and light gas oil in pilot-scale
hydrodesulfurization unit over
commercial CoMo/Al2O3

ดร.เจดิ ศกั ด์ิ ไชยคนุ า ภาควช� าวศ� วกรรมเคมี
0-2218-6891 [email protected]

The effect of the presence of palm fatty acid distillate (PFAD) during co-processing with
light gas oil (LGO) in hydrodesulfurization unit has been carried out in a near adiabatic,
pilot-scale, and fixed-bed hydrotreating reactor, over commercial CoMo/Al2O3 under
280–350 °C, 25 barg, H2/feed ratio of 630 Nm3/m3 and 0.75 h−1. The amount of PFAD 5, 8, 12,
and 25 wt% of PFAD in LGO was the feed mixtures. High conversion range on both
desulfurization and deoxygenation reactions were achieved by every fraction of PFAD. The
hydrocarbon products contained sulfur lower than 50 ppmw and neutralization number
lower than 0.1 mg KOH/g. These products can be claimed as EURO 4 diesel following EN 590.
The presence of PFAD in LGO improved the cetane index of the liquid products while lowered
the product density. Highly heat effect was observed by an increasing of the reactor
temperature up to 62 °C at the reactor outlet in the case of 25 wt% of PFAD. The increasing of
the reactor temperature was resulting from an increasing amount of PFAD in LGO. The higher
amount of PFAD slightly facilitated deoxygenation reaction, but impeded hydrodesulfurization
reaction. The temperature rise also increased hydrocracking reaction evidenced by the lower
contribution of total n-paraffin to the product mixture at higher PFAD in LGO. Finally, the
hydrogen consumption was observed as linearly increased with an increasing amount of
PFAD. The consumption was then theoretically calculated and extrapolated for hydrotreating
of pure PFAD at 300 and 344 Nm3/m3, respectively. An additional hydrogen consumption of
44 Nm3/m3 was studied and discussed.

FULL PAPER (LINK)

ดเู พมิ่ เตมิ ไดที่วารสาร
Fuel
ตีพิมพป 2017 เดือนกรกฎาคม ฉบบั ท่ี 199 หนา 115-124
https://www.sciencedirect.com/science/article/pii/S0016236117302193

หนว ยสอ่ื สารองคก ร [email protected]

Formation mechanism of sPEEK
hydrophilized PES supports
for forward osmosis

อ. ดร.ชลดิ า คลา ยโสม ภาคว�ชาวศ� วกรรมเคมี
0-2218-6893 [email protected]

ABSTRACT

Polyethersulfone/sulfonated polyetheretherketone (PES/sPEEK) supported
osmotic thin film composite (TFC) membranes were fabricated with a focus on
the optimization of the support layer of the TFC membrane by the phase inver-
sion process. The polymer solution was cast directly on a glass substrate without
any backing fabric to prepare the support layer. All resultant supports showed a
fingerlike pore structure. The addition of a more hydrophilic polymer (sPEEK) to
the polymer solution induced pores in the bottom layer of the support with
average pore diameters ranging from 0.07 to 0.30 μm, which improved water
flux. Bottom surface porosities were simply controlled by adjusting the polymer
blend ratios. FO experiments were carried out in a high-throughput (HT) cross-
flow FO cell with DI water and a 0.5 M NaCl solution as feed and draw solution,
respectively. TFC membranes with 5% sPEEK showed a water flux in PRO mode
of 14.3 LMH and in FO mode of 6.2 LMH, which is superior to the commercial
cellulose triacetate (CTA) and TFC membranes (HTI). In addition, a mechanism
for the bottom layer formation was proposed.

FULL PAPER (LINK)

ดูเพิ่มเติมไดท่วี ารสาร
Desalination
ตพี มิ พป 2017 เดือนตลุ าคม ฉบับที่ 419 หนา 29-38
https://www.sciencedirect.com/science/article/pii/S0011916417307543

หนว ยสอ่ื สารองคก ร [email protected]

Recent membrane developments
for CO2 separation and capture

อ. ดร.ชลดิ า คลา ยโสม ภาควช� าวศ� วกรรมเคมี
0-2218-6893 [email protected]

ABSTRACT

Increasing concerns on global warming and climate change have led to
numerous attempts and advanced technology developments to tackle the
problem of excessive greenhouse gases emitted to the atmosphere. One of the
technical strategies receiving great attention is the application of membrane
technology for greenhouse gas separation/capture. Such technology exhibits
significant advantages over other conventional methods in terms of removal
efficiency, compactness, and environmental friendliness. Many state‐of‐the‐art
membrane developments as well as its applications to post‐combustion treat-
ment, which could be a promising approach for reducing CO2 emission from
point sources, are thoroughly reviewed. Furthermore, a comprehensive survey
on the future perspective of membrane technologies as a potential solution for
CO2 removal and utilization is provided.

FULL PAPER (LINK)

ดูเพม่ิ เติมไดท ่ีวารสาร
Chemical Engneering & Technology
ตพี ิมพป 2018 เดือนมกราคม ฉบบั ที่ 41 หนา 211-223
https://onlinelibrary.wiley.com/doi/abs/10.1002/ceat.201700406

หนว ยสอ่ื สารองคก ร [email protected]

H2 production from sorption enhanced
steam reforming of biogas using
multifunctional catalysts of Ni over
Zr-, Ce- and La-modified CaO sorbents

อ. ดร.พลัง บำรงุ สกลุ สวัสด์ิ ภาคว�ชาวศ� วกรรมเคมี
0-2218-6870 [email protected]

ABSTRACT

Sorption enhanced steam reforming of biogas is a promising process for H2 production by which
biogas steam reforming is combined with simultaneous CO2 capture in a single unit
operation. In the first part, Zr4+, Ce4+ and La3+ were doped on CaO and tested the performance for 10

CO2 sorption/desorption cycles. Zr-CaO and Ce-CaO offered a stable CO2 capture activity for at least
10 cycles (CO2 sorption capacity of 0.30 and 0.22 gCO2/gsorbent at the 1st cycle, and 0.29 and 0.23 gCO2/
gsorbent at the 10th cycle for Zr-CaO and Ce-CaO, respectively). On the other hand, La-CaO indicated
decreasing of CO2 sorption capacity about 16% over 10 cycle operations. This is due to the Zr-CaO
and Ce-CaO presented oxygen storage at low temperature which is characterized by temperature

program reduction oxidation (TPRO). This behavior promotes the CO2 diffusion from the surface to
the bulk (sorption) and the bulk to the surface (desorption) of the modified CaO. In the second part,

Ni2+ was loaded on the modified sorbents for H2 production. Ni-Zr-CaO and Ni-Ce-CaO can enable
the production of H2 with purities of approximately 90% and 85%, respectively, with repeating
cycles; however, the CH4 conversions decreased significantly over five cycles (the post-breakthrough
period CH4 conversion of Ni-Zr-CaO and Ni-Ce-CaO decreased from 65.6 and 56.3% during the 1st
cycle to 33.0 and 28.9% during the 5th cycle). This is because the Ni active sites at the surface of

multifunctional catalysts were lost (as confirmed by XPS results) by pore closure (as shown in SEM

images) which was possibly due to the CaCO3 formation.

FULL PAPER (LINK)

ดเู พมิ่ เติมไดท่วี ารสาร
Chemical Engineering Journal
ตีพิมพป  2017 เดอื นเมษายน ฉบับท่ี 313 หนา 1415-1425
https://www.sciencedirect.com/science/article/pii/S1385894716316138

หนว ยสอ่ื สารองคก ร [email protected]



Design equations for undrained
stability of opening in
underground walls

รศ. ดร.บญุ ชยั อกุ ฤษฏชน ภาควช� าวศ� วกรรมโยธา
0-2218-6695 [email protected]

ABSTRACT

Undrained stability of an opening in underground walls in clays with
constant and linearly increasing shear strengths with depth was
investigated by two-dimensional finite element limit analysis under
plane strain condition. Three parametric studies were performed to
study the effects of the cover depth ratio, overburden stress factor and
linear strength gradient ratio on the load factor of the opening in
underground walls. Predicted failure mechanisms associated with
these parameters were discussed and examined. New design equations
for the undrained stability of an opening in underground walls in clays
with an arbitrary linear increase in strength with depth were developed
for a practical application in the field of trenchless constructions.

FULL PAPER (LINK)

ดูเพมิ่ เติมไดท ่ีวารสาร
Tunnelling and Underground Space Technology
ตีพมิ พป 2017 เดอื นพฤศจกิ ายน ฉบบั ที่ 70 หนา 214-220
https://www.sciencedirect.com/science/article/pii/S0886779817301177

หนว ยสอ่ื สารองคก ร [email protected]

Discussion of “numerical limit analysis
of three-dimensional slope stability
problems in catchment areas”
by Camargo et al.
(doi:10.1007/s11440-016-0459-3)

รศ. ดร.บุญชัย อกุ ฤษฏชน ภาคว�ชาวศ� วกรรมโยธา
0-2218-6695 [email protected]

ABSTRACT

A paper recently published by Camargo et al. (Acta Geotech
11(6):1369–1383, 2016) (hereafter identified as“the authors”) presented
the numerical limit analysis method (NLA) to compute the safety factor
and collapse mechanism of three-dimensional (3D) slopes. For NLA, the
authors employed the discrete three-dimensional lower bound
formulation with pore water pressure consideration and
Drucker–Prager yield criterion, and cast a slope problem as a
second-order conic programming problem. The developed program
was implemented in MATLAB and validated through three examples of
slope problems, and was applied to solve a large-scale 3D slope
problem of a failure case study. The discussion of this article focuses on
the formulation of the developed 3D NLA and static admissibility of
stress field solutions obtained from NLA.

FULL PAPER (LINK)

ดูเพม่ิ เติมไดท ่ีวารสาร
Acta Geotechnica
ตีพิมพป 2017 เดอื นตุลาคม ฉบับท่ี 12 หนา 1185-1187
https://link.springer.com/article/10.1007%2Fs11440-017-0589-2

หนว ยสอ่ื สารองคก ร [email protected]

Error in Ito and Matsui's
limit-equilibrium solution of lateral
force on a row of stabilizing piles

รศ. ดร.บุญชยั อุกฤษฏชน ภาคว�ชาวศ� วกรรมโยธา
0-2218-6695 [email protected]

ABSTRACT

Stabilizing piles are commonly employed as an effective approach
for slope or landslide stabilization. The limit equilibrium solution of a
pile force acting on a row of stabilizing piles proposed by Ito and Matsui
(1975) has been widely adopted by researchers to develop a general
method of stability analysis for a slope reinforced by piles, such as the
friction circle method (Hassiotis et al. 1997), the upper bound limit anal-
ysis (Li et al. 2012), and others. Thus far, the accuracy of Ito and Matsui’s
solution has not been investigated despite its numerous applications in
research and practice.

FULL PAPER (LINK)

ดูเพมิ่ เติมไดทว่ี ารสาร
Journal of Geotechnical and Geoenvironmental Engineering
ตพี มิ พป  2017 เดือนกันยายน ฉบับท่ี 143 หมายเลขบทความ 02817004

https://ascelibrary.org/doi/pdf/10.1061/%28ASCE%29GT.1943-5606.0001753

หนว ยสอ่ื สารองคก ร [email protected]

Finite element analysis of undrained
stability of cantilever flood walls

รศ. ดร.บญุ ชยั อุกฤษฎชน ภาคว�ชาว�ศวกรรมโยธา
0-2218-6695 [email protected]

ABSTRACT

In this study, new undrained stability solutions of cantilever flood
walls in clay were proposed and solved by finite element analysis with a
two-dimensional plane strain condition. The analysis considered flood
walls in homogeneous and non-homogeneous clay layers, where the
latter corresponded to a linear increase in shear strength with depth.
Two parametric studies were performed for embedded length ratios and
dimensionless strength gradients. Results were summarised in the form
of design charts for stability number, normalised maximum shear force
and normalised maximum bending moment as a function of those two
parameters. Closed-form solutions were proposed for a convenient and
accurate evaluation of undrained stability of flood walls in practice, and
their applications were demonstrated through a back analysis of a case
study. © 2016 Informa UK Limited, trading as Taylor & Francis Group.

FULL PAPER (LINK)

ดเู พม่ิ เตมิ ไดท่วี ารสาร
International Journal of Geotechnical Engineering
ตีพิมพป  2017 เดือนสิงหาคม ฉบบั ที่ 4 หนา 355-367
https://www.tandfonline.com/doi/full/10.1080/19386362.2016.122204

หนว ยสอ่ื สารองคก ร [email protected]

Finite element analyses
of the stability of a soil block
reinforced by shear pins

รศ. ดร.บุญชยั อุกฤษฎชน ภาคว�ชาวศ� วกรรมโยธา
0-2218-6695 [email protected]

ABSTRACT

The assessment of slope stability is an essential task in geotechnical engineering.
In this paper, a three-dimensional (3D) finite element analysis (FEA) was employed to
investigate the performance of different shear pin arrangements to increase the stability of
a soil block resting on an inclined plane with a low-interface friction plane. In the numerical
models, the soil block was modeled by volume elements with linear elastic perfectly plastic
material in a drained condition, while the shear pins were modeled by volume elements
with linear elastic material. Interface elements were used along the bedding plane
(bedding interface element) and around the shear pins (shear pin interface element) to
simulate the soil-structure interaction. Bedding interface elements were used to capture
the shear sliding of the soil on the low-interface friction plane while shear pin interface
elements were used to model the shear bonding of the soil around the pins.
A failure analysis was performed by means of the gravity loading method. The results of
the 3D FEA with the numerical models were compared to those with the physical models
for all cases. The effects of the number of shear pins, the shear pin locations, the different
shear pin arrangements, the thickness and the width of the soil block and the associated
failure mechanisms were discussed.

FULL PAPER (LINK)

ดูเพม่ิ เตมิ ไดท ี่วารสาร
Geomechanics and Engineering
ตีพิมพป  2017 ฉบบั ที่ 12 หนา 1021-1046

http://koreascience.or.kr/article/ArticleFullRecord.jsp?cn=TPTPHF_2017_v12n6_1021

หนว ยสอ่ื สารองคก ร [email protected]

Optimal design of Reinforced
Concrete Cantilever Retaining Walls
considering the requirement of
slope stability

รศ. ดร.บุญชัย อกุ ฤษฏชน ภาคว�ชาว�ศวกรรมโยธา
0-2218-6695 [email protected]

ABSTRACT

A Reinforced Concrete Cantilever Retaining Wall (RCCRW) is one commonly used soil
retaining structure in engineering practice. Various optimization techniques to obtain the optimal
design of cantilever walls have been proposed, where the three basic geotechnical constraints of
overturning, sliding and bearing failures have generally been taken into consideration. However,
none of these approaches have considered the geotechnical requirement of slope stability. In this
paper, a novel formulation for the optimal design of RCCRWs that considers the more complete
requirements of geotechnical stability of overturning, sliding, bearing and slope failures,
is described. The objective function of the minimum cost of materials, geotechnical constraints of
wall failures (overturning, sliding and bearing) and the structural requirements for steel
reinforcements in the wall sections all followed the conventional approaches used in previous
works. Using the Ordinary Method of Slices (OMS) with a circular arc failure surface (CAFS), the factor
of safety against slope failure (FS OMS ) for a RCCRW was implicitly derived. Constraints for ensuring
that the minimum FS OMS was higher than the required factor were enforced in the
formulation. Design variables were the dimensions of the wall sections, corresponding steel
reinforcements and the x-y coordinate of center of the CAFS, where the latter are the additional
unknowns in this novel formulation. Computational performance of the proposed optimization
method is demonstrated and verified through its application to the optimal design of two examples
of RCCRWs.

FULL PAPER (LINK)

ดูเพิม่ เตมิ ไดท่วี ารสาร
KSCE Journal of Civil Engineering
ตพี ิมพป 2017 เดือนพฤศจิกายน ฉบับที่ 21 หนา 2673-2682
https://link.springer.com/article/10.1007/s12205-017-1627-1

หนว ยสอ่ื สารองคก ร [email protected]

Stability of unsupported
conical excavations in
non-homogeneous clays

รศ. ดร.บญุ ชยั อกุ ฤษฏชน ภาควช� าวศ� วกรรมโยธา
0-2218-6695 [email protected]

ABSTRACT

New plasticity solutions for the undrained stability of unsupported
conical excavations in homogeneous and non-homogeneous clays were
solved by axisymmetric finite element limit analysis. Three parametric
studies were performed on excavated height ratios, slope inclinations and
dimensionless strength gradients. In all cases, the exact stability factors
were accurately bracketed by computed bound solutions within 0.6%.
An accurate closed-form equation of the stability factor was proposed
from nonlinear regression analysis of lower bound solutions. New conical
stability factors for soil cohesion, strength gradient, and coupling effect of
these components were deduced to conveniently and accurately predict
a safe solution in practice.

FULL PAPER (LINK)

ดเู พม่ิ เติมไดท ีว่ ารสาร
Computers and Geotechnics
ตีพิมพป 2017 เดอื นมกราคม ฉบบั ที่ 81 หนา 125-136
https://www.sciencedirect.com/science/article/pii/S0266352X16301756

หนว ยสอ่ื สารองคก ร [email protected]

Undrained limiting pressure
behind soil gaps in contiguous
pile walls

รศ. ดร.บุญชยั อุกฤษฏชน ภาคว�ชาวศ� วกรรมโยธา
0-2218-6695 [email protected]

ABSTRACT

Finite element limit analysis with plane strain condition is employed
to determine the upper and lower bound solutions of the undrained
limiting pressure behind soil gaps and the lateral force acting on a pile
per unit length in a contiguous pile wall. Computed bound solutions
confirm serious limitations of existing studies in predicting these two
solutions. Predicted failure mechanisms and the arching effect behind
soil gaps are discussed. A closed-form equation of the limiting pressure
factor is proposed for a convenient and accurate prediction of the
lateral force acting on a pile in contiguous pile walls in practice.

FULL PAPER (LINK)

ดเู พมิ่ เตมิ ไดท ีว่ ารสาร
Computers and Geotechnics
ตพี ิมพป 2017 เดือนมนี าคม ฉบบั ที่ 83 หนา 152-158
https://www.sciencedirect.com/science/article/pii/S0266352X16302749

หนว ยสอ่ื สารองคก ร [email protected]

Undrained stability of an active
planar trapdoor in non-homogeneous
clays with a linear increase of strength
with depth

รศ. ดร.บุญชัย อกุ ฤษฏชน ภาควช� าว�ศวกรรมโยธา
0-2218-6695 [email protected]

ABSTRACT

Finite element limit analysis was employed to determine the upper and
lower bound solutions of the active failure of a planar trapdoor in
non-homogeneous clays that have a linear increase of strength with
depth. Influences of cover ratio, dimensionless strength gradient and
trapdoor roughness on predicted failure mechanisms and stability factors
were determined. In all cases, the exact stability factors were accurately
bracketed by computed bound solutions within 1%. Accurate
closed-form equations to predict the exact estimates of stability factors,
trapdoor pressure and factor of safety using the new proposed factors for
the cohesion and strength gradient are presented.

FULL PAPER (LINK)

ดูเพิม่ เติมไดที่วารสาร
Computers and Geotechnics
ตพี ิมพป  2017 เดอื นมกราคม ฉบับที่ 81 หนา 284-293
https://www.sciencedirect.com/science/article/pii/S0266352X16301951

หนว ยสอ่ื สารองคก ร [email protected]

Unsafe error in conventional shape
factor for shallow circular foundations
in normally consolidated clays

รศ. ดร.บุญชยั อกุ ฤษฏชน ภาควช� าว�ศวกรรมโยธา
0-2218-6695 [email protected]

ABSTRACT

In practice, a factor of 1.2 is generally accepted as the shape factor
for undrained bearing capacity of surface foundations in homogeneous
clays between axisymmetric (AS) and plane strain (PS) conditions.
This empirical shape factor first proposed by Skempton has been
widely adopted in design guidelines for shallow foundations to
determine general undrained bearing capacity of circular foundations
from standard solutions for strip foundations. However, this factor is
unsafe and should not be used for shallow circular foundations in
normally consolidated (NC) clay with shear strength increasing linearly
with depth from zero at the ground surface.

FULL PAPER (LINK)

ดูเพิม่ เตมิ ไดท่วี ารสาร
Journal of Geotechnical and Geoenvironmental Engineering
ตีพิมพป  2017 เดอื นมิถนุ ายน ฉบบั ท่ี 143 หมายเลขบทความ 02817001

https://ascelibrary.org/doi/pdf/10.1061/%28ASCE%29GT.1943-5606.0001670

หนว ยสอ่ื สารองคก ร [email protected]

Shear capacity of high
performance fiber reinforced
concrete I-beams

รศ. ดร.วท� ิต ปานสขุ ภาคว�ชาวศ� วกรรมโยธา
0-2218-6693 [email protected]

ABSTRACT

An experimental program was carried out to investigate the shear capacity
of High-Performance Fiber-Reinforced Concrete (HPFRC) I-beams. The main
parameters were assigned as the fiber content and presence of shear
reinforcement. To study the effect of these main parameters on the shear
capacity, testing of six I-beams and other control specimens was conducted.
It can be observed from the results of the experimental study that the
presenceof fibers and shear reinforcement significantly improves the
ultimate capacity and structural behavior of HPFRC members. Finally, the
experimental results are discussed, and the shear capacity of HPFRC can be
estimated by extending the code provisions stated in AFGC-Sétra 2013.

FULL PAPER (LINK)

ดเู พิม่ เตมิ ไดท่ีวารสาร
Construction and Building Materials
ตพี มิ พป 2017 เดือนธันวาคมฉบับท่ี 157 หนา 182-193

https://www.sciencedirect.com/science/article/pii/S0950061817318585

หนว ยสอ่ื สารองคก ร [email protected]

Analysis of fatigue crack propagation
in steel I-Beams with welded transverse
stiffeners subjected to in-plane loadings

รศ. ดร.อัครวัชร เลน วาร� ภาควช� าว�ศวกรรมโยธา
[email protected]
0-2218-6693

ABSTRACT

For bridge structures, the fatigue crack propagation represents the mechanical
damage that shortens the service life of the structures. Most fatigue cracks initiate at the
welded details due to geometric discontinuities, residual stresses, and initial weld
defects. The welded transverse stiffeners have been widely used to increase shear
strength of the steel girders. Under cyclic in-plane loadings, however, the fatigue crack
initiates at the end of the stiffener, i.e., in the web gap, and propagates into the girder
web. The objectives of this study are to (1) numerically simulate the fatigue crack propa-
gation in steel I-girders with welded transverse stiffeners and (2) study the effects of
initial crack size, fillet weld size, stiffener dimension, and web-gap length on the fatigue
crack propagation. The FRANC3D software was used to perform the analysis of stress
intensity factor, crack propagation, and fatigue life. The numerical results showed that
the fatigue life increases as the web-gap length increases, while it decreases as initial
crack size and thickness of the transverse stiffener increase. Also, the stress intensity
factors of the steel I-beams that include the fillet weld in the finite element models are
slightly lower than ones modelled without fillet weld.

FULL PAPER (LINK)

ดเู พิ่มเติมไดทว่ี ารสาร
Engineering Journal
ตพี มิ พป 2017 เดือนกรกฎาคม ฉบับที่ 21 หนา 307-324
http://www.engj.org/index.php/ej/article/view/1489/625

หนว ยสอ่ื สารองคก ร [email protected]

Thermal analysis for peak temperature
distribution in reinforced concrete beams
after exposure to ASTM E119 standard fire

รศ. ดร.อคั รวชั ร เลน วาร� ภาควช� าวศ� วกรรมโยธา
[email protected]
0-2218-6693

ABSTRACT

To assess the post-fire or residual strength of fire-damaged reinforced concrete (RC) members, the
most detrimental or peak temperature distribution within the members should be perceived. For RC
beams, the residual flexural response is strongly influenced by the peak temperature experienced by
the steel reinforcements. This paper presents a simplified two-dimensional (2D) nonlinear transient
thermal analysis for the peak temperature distribution in RC beams using the finite element method. In
the analysis, the thermal loading for heating was the ASTM E119 standard fire. After heating, a linear
decrease in temperature was assumed for cooling. Three-sided fire exposure was assumed for rectan-
gular RC beams. The analysis was used to investigate the effects of the heating period (1-4 h), cooling
period (1-4 h), concrete cover thickness (30-50 mm) and aggregate type (carbonate or siliceous aggre-
gates) on the peak steel temperature and delayed time (time to attain the peak temperature after heat-
ing). The numerical results showed that the temperature inside the beam section continues to rise after
heating. The increases in steel temperature after heating and delayed time are influenced by the heat-
ing period, cooling period, location of steel reinforcement, and aggregate type. Such increase is signifi-
cant for the beam with a thick concrete covering subjected to a short heating period followed by a long
cooling period. At the longest (4 h) cooling and shortest (1 h) heating periods, the increases in steel
temperature after heating in both carbonate and siliceous concrete beams are approximately 35, 50
and 75% for concrete cover thicknesses of 30, 40, and 50 mm, respectively. The carbonate concrete
beams are more vulnerable to fire damage than siliceous ones when subjected to long heating and

FULL PAPER (LINK)

ดเู พิม่ เตมิ ไดท ี่วารสาร
Engineering Journal
ตพี ิมพป  2017 เดอื นกรกฎาคม ฉบับท่ี 21 หนา 243-258
http://www.engj.org/index.php/ej/article/view/1279/624

หนว ยสอ่ื สารองคก ร [email protected]

Development of a size-based multiple
erosion technique to estimate the aggregate
gradation in an asphalt mixture

ผศ. ดร.บุญชยั แสงเพชรงาม ภาควช� าวศ� วกรรมโยธา
0-22186697 [email protected]

ABSTRACT

Image processing (IP) techniques have recently been applied in the field
of asphalt materials to help identify aggregate particles and measure
their geometrical information based on sectional images of the material.
This study examined IP techniques to improve the accuracy of analyzing
the size distribution of aggregates in an asphalt mixture, and proposed
two new methods: seven-layer overlaying (SLO) and size-based multiple
erosion (SBME) to solve the problem of identifying connected aggregate
particles that often occurs in typical IP applications. The proposed meth-
ods were tested for their effectiveness with a typical IP method using a
referenced sectional image of asphalt mixture. Both the proposed meth-
ods successfully improved the accuracy of detection (number and size
distribution) of aggregate particles, but the SBME approach was superior
over the SLO method.

FULL PAPER (LINK)

ดเู พิม่ เตมิ ไดทว่ี ารสาร
Engineering Journal
ตีพมิ พป 2017 เดอื นกันยายน ฉบบั ที่ 21 หนา 315-331
http://www.engj.org/index.php/ej/article/view/1540/636

หนว ยสอ่ื สารองคก ร [email protected]



Application of structured support
vector machine backpropagation
to a convolutional neural network
for human pose estimation

ศ. ดร.ประภาส จงสถิตยว ฒั นา ภาควช� าวศ� วกรรมคอมพว� เตอร
0-2218-6982 Email: [email protected]

ABSTRACT

In this study, for the first time, we show how to formulate a structured
support vector machine (SSVM) as two layers in a convolutional neural
network, where the top layer is a loss augmented inference layer and the
bottom layer is the normal convolutional layer. We show that a deformable
part model can be learned with the proposed structured SVM neural
network by backpropagating the error of the deformable part model to
the convolutional neural network. The forward propagation calculates
the loss augmented inference and the backpropagation calculates the
gradient from the loss augmented inference layer to the convolutional
layer. Thus, we obtain a new type of convolutional neural network called
an Structured SVM convolutional neural network, which we applied to
the human pose estimation problem. This new neural network can be
used as the final layers in deep learning. Our method jointly learns the
structural model parameters and the appearance model parameters.
We implemented our method as a new layer in the existing Caffe library.

FULL PAPER (LINK)

ดูเพิม่ เตมิ ไดที่วารสาร
Neural Networks
ตีพมิ พป 2017 เดือนสิงหาคม ฉบบั ที่ 92 หนา 39-46

https://www.sciencedirect.com/science/article/pii/S0893608017300321

หนว ยสอ่ื สารองคก ร [email protected]

Road segmentation of remotely-sensed
images using deep convolutional neural
networks with landscape metrics and
conditional random fields

ผศ. ดร.พร� พล เวทกี ลู ภาควช� าว�ศวกรรมคอมพว� เตอร
0-2218-6989 [email protected]

ABSTRACT

Object segmentation of remotely-sensed aerial (or very-high resolution, VHS) images
and satellite (or high-resolution, HR) images, has been applied to many application
domains, especially in road extraction in which the segmented objects are served as a man-
datory layer in geospatial databases. Several attempts at applying the
deep convolutional neural network (DCNN) to extract roads from remote sensing images
have been made; however, the accuracy is still limited. In this paper, we present an
enhanced DCNN framework specifically tailored for road extraction of remote sensing
images by applying landscape metrics (LMs) and conditional random fields (CRFs).
To improve the DCNN, a modern activation function called the exponential linear unit (ELU),
is employed in our network, resulting in a higher number of, and yet more
accurate, extracted roads. To further reduce falsely classified road objects, a solution based
on an adoption of LMs is proposed. Finally, to sharpen the extracted roads, a CRF method is
added to our framework. The experiments were conducted on Massachusetts road aerial
imagery as well as the Thailand Earth Observation System (THEOS) satellite imagery data
sets. The results showed that our proposed framework outperformed Segnet, a
state-of-the-art object segmentation technique, on any kinds of remote sensing imagery, in
most of the cases in terms of precision, recall, and F1.

FULL PAPER (LINK)

ดเู พ่ิมเตมิ ไดทีว่ ารสาร
Remote Sensing
ตพี มิ พป  2017 เดอื นกรกฎาคม ฉบบั ท่ี 7 หมายเลขบทความ 680
http://www.mdpi.com/2072-4292/9/7/680

หนว ยสอ่ื สารองคก ร [email protected]



Analysis of multi-objective optimal dispatch
of cogeneration with thermal energy storage
for building energy management system

ศ. ดร.เดวด� บรรเจดิ พงศช ัย ภาคว�ชาว�ศวกรรมไฟฟา
0-2218-6487 [email protected]

ABSTRACT

This paper presents analysis of the multi-objective optimal operation of designed BEMS
which contains cogeneration or combined heat and power (CHP) and thermal energy storage
(TES) as energy sources. The previously designed BEMS consists of CHP as the main energy
supply with absorption chiller and auxiliary boiler. It is observed that there is excessive heat
energy from CHP operation which is enough for further utilization. In this paper, TES is additional
component to utilize excessive heat energy released from CHP operation. TES cooperates with
CHP and auxiliary boiler to supply heat energy to meet the cooling load demand in the building.
There are two objective functions for consideration, namely, total operating cost (TOC) and total
carbon dioxide emission (TCOE). The multi-objective framework combines both objective func-
tions and employs the weighted sum of TOC and TCOE. Furthermore, we vary initial state of TES
from 0-20% of TES’s capacity and analyze its effect on TOC and TCOE. We apply the multi-objec-
tive approach to a large shopping mall. Numerical results show that setting initial state of TES to
0% can offer more reduction of TOC and TCOE than other initial conditions. The multi-objective
optimal operation converges to minimum TOC when a weighting factor is 0. On the other hand,
it converges to the minimum TCOE when the weighting factor is 1. In addition, the trade-off
curve showing a relationship between TOC and TCOE provides operating points which depends
on operator’s decision criterion.

FULL PAPER (LINK)

ดูเพ่ิมเติมไดที่วารสาร
Engineering Journal
ตพี มิ พป 2017 เดือนกันยายน ฉบบั ท่ี 21 หนา 67-79
http://www.engj.org/index.php/ej/article/view/1471/639

หนว ยสอ่ื สารองคก ร [email protected]

Growth of truncated pyramidal
InSb nanostructures on
GaAs substrate

ศ. ดร.ทรงพล กาญจนชูชยั ภาคว�ชาว�ศวกรรมไฟฟา
0-2218-6522 [email protected]

ABSTRACT

Growth and structural characterization of InSb nanostructures formed
on GaAs is presented. Saturated InSb nanostructure have a truncated
pyramidal shape with rectangular base. In addition, some InSb
nanostructures have twin truncated pyramidal configurations. The twin
truncated pyramids align in parallel with each other and along [110]
direction. We attribute the formation of rectangular base to the growth
of highly mismatched InSb/GaAs system while the formation of twin
configuration due to the nucleation of InSb islands on top of
two-dimensional InSb plateau. The latter is suggested by an
observation on the initial state of InSb nanostructure formation.

FULL PAPER (LINK)

ดเู พิ่มเติมไดท ว่ี ารสาร
Journal of Crystal Growth
ตพี ิมพป  2017 เดอื นกรกฎาคม ฉบับที่ 468 หนา 737-739
https://www.sciencedirect.com/science/article/pii/S0022024816308028

หนว ยสอ่ื สารองคก ร [email protected]

Morphology of self-assembled
InSb/GaAs quantum dots on
Ge substrate

ศ. ดร.ทรงพล กาญจนชชู ยั ภาควช� าว�ศวกรรมไฟฟา
0-2218-6522 [email protected]

ABSTRACT

In this work, we report on the growth of self-assembled InSb/GaAs
quantum dots (QDs) on (001) Ge substrate by molecular beam epitaxy.
Due to the polar/non-polar nature of GaAs grown on Ge, antiphase
domains are formed. Effects of the domain and QD growth temperature
on the morphology of realized QDs are presented. InSb QDs are mostly
formed at the antiphase-domain boundaries (APBs). The QD size, shape
and density are varied with the QD growth temperature. These
free-standing QDs have irregular lens and stripe-shapes with {10n} side
facets according to the analysis of atomic force microscopy images.
InSb QDs is formed at the APBs, where two orthogonal GaAs surfaces
are met.

FULL PAPER (LINK)

ดเู พม่ิ เติมไดทวี่ ารสาร
Journal of Crystal Growth
ตพี มิ พป 2017 เดือนมถิ นุ ายน ฉบับท่ี 468 หนา 541-546
https://www.sciencedirect.com/science/article/pii/S0022024816306935

หนว ยสอ่ื สารองคก ร [email protected]

Planar Self-Assembly of Submicron
and Nanoscale Wires and Grooves
on III-V(110) Surfaces

ศ. ดร.ทรงพล กาญจนชูชยั ภาควช� าว�ศวกรรมไฟฟา

0-2218-6522 [email protected]

ABSTRACT

Metallic Ga and In submicron and nanowires (NWs) tens of microns long naturally
form via a self-propelled mechanism on the (110) surfaces of GaAs and InAs,
respectively, during noncongruent sublimation in ultrahigh vacuum. Under stringent
conditions, low-energy electron microscopy uncovers GaAs and InAs(110) surfaces on
the brink of decomposition rapidly assemble planar wires of their cations in the «110»
direction. For InP(110), wire formation is unfavorable due to a smooth decomposing
front but can be assisted by Au nanoparticles (NPs), which sacrifice themselves to
form rough pits via solid-liquid-vapor etching. The resulting self-assembled and
AuNP-assisted NWs grow crystallographically in a self-sustainable manner, unless
they are obstructed and consumed by stationary microdroplets, leaving emptied
grooves. The findings reveal a hitherto hidden natural process on the surfaces of
binary crystals capable of producing elementary submicron and nanoscale wires
without extrinsic materials, paving the way for the controlled fabrication of planar
NWs, grooves, and NW/groove arrays with lengths approaching circuits or even chips
scale and with potential applications in self-integrated circuits, plasmonics,
and fluidics.

FULL PAPER (LINK)

ดูเพิ่มเติมไดที่วารสาร
Crystal Growth and Design
ตพี มิ พป 2017 เดอื นสิงหาคม ฉบับท่ี 17 หนา 4413-4421
https://pubs.acs.org/doi/10.1021/acs.cgd.7b00707

หนว ยสอ่ื สารองคก ร [email protected]

Achievable rate region for the two-user
Gaussian X channel with limited receiver
cooperation: General case

ศ. ดร.วาทติ เบญจพลกุล ภาคว�ชาว�ศวกรรมไฟฟา
0-2218-6902 [email protected]

ABSTRACT

In this paper, we propose to use a strategy for the two-user Gaussian X
channel with limited receiver cooperation in the general case consisting
of two parts: 1) the transmission scheme where the superposition coding
is used and 2) the cooperative protocol where the two-round strategy
based on quantize-map-and-forward (QMF) is employed. We image that a
Gaussian X channel can be considered as a superposition of two Gaussian
interference channels based on grouping of the sent messages from each
transmitter to the corresponding receivers. Finally, we give an achievable
rate region for the general case of this channel.

FULL PAPER (LINK)

ดูเพม่ิ เติมไดท ่ีวารสาร
IEICE Transactions on Fundamentals of Electronics, Communications
and Computer Sciences
ตีพิมพป  2017 เดอื นมีนาคม ฉบับท่ี E100A หนา 822-831
https://www.worldscientific.com/doi/abs/10.1142/S0218126617500086

หนว ยสอ่ื สารองคก ร [email protected]

Sum-rate upper bounds for the two-user
Gaussian X channel with limited receiver
cooperation

ศ.ดร.วาทิต เบญจพลกุล ภาควช� าวศ� วกรรมไฟฟา
0-2218-6902 [email protected]

ABSTRACT

In this paper, we propose sum-rate upper bounds in terms of the sum of 3
rates and the sum of 4 rates for the two-user Gaussian X channel with limited
receiver cooperation. These upper bounds are derived by using the Fano’s
inequality, the data processing inequality and Genie-aided techniques. Then,
we explore the generalized degrees of freedom (GDoF) of the proposed
upper bounds with a symmetric channel setting. By setting a certain set of
parameters, the received results show that our results are identical to the
existing results for both non-cooperation and limited receiver cooperation
cases. Moreover, we obtain that the GDoF computed from our proposed
upper bounds are greater than the GDoF of those in the non-cooperation
case. © 2017, ECTI Association. All Rights Reserved.

FULL PAPER (LINK)

ดูเพ่มิ เติมไดท ่วี ารสาร
Transactions on Electrical Engineering, Electronics, and
Communications
ตีพิมพป 2017 เดือนมกราคม ฉบับท่ี 15 หนา 26-35

หนว ยสอ่ื สารองคก ร [email protected]

QoS metrics modeling and analysis for
neighborhood area network in smart grid
applications

ศ. ดร.วาทิต เบญจพลกุล ภาคว�ชาวศ� วกรรมไฟฟา
0-2218-6902 [email protected]

ABSTRACT

Recently, planning and designing of smart-grid (SG) neighborhood area network
(NAN) communication architecture has drawn wide attention of researchers. In order
to establish an SG NAN scheme satisfying the requirement, a quality of service (QoS)
metric is a critical demand. However, there are few studies on the implementation of
an efficient QoS metric model. In this paper, we propose an innovative QoS metric
model for SG NAN design. By exploring the natural characteristics of SG messages in
many applications, we choose the reliability and latency of a message as the most
important criteria and implement the QoS curve for evaluating the performance of
any candidate communication scheme. In addition, we present the evaluation model
for QoS metrics of multiple SG services in NAN. Compared to other existing QoS meth-
ods, our model is easy to use and helps to reduce the time and cost in the planning
and designing of a NAN for SG. Simulation and analysis results indicate good agree-
ment with our proposed QoS model.

FULL PAPER (LINK)

ดูเพม่ิ เติมไดที่วารสาร
IEEJ Transactions on Electrical and Electronic Engineering
ตีพิมพป 2017 เดือนมิถนุ ายน ฉบบั ท่ี 12 หนา S79-S88
https://onlinelibrary.wiley.com/doi/full/10.1002/tee.22442

หนว ยสอ่ื สารองคก ร [email protected]

Molecular beam epitaxy growth
of InSb/GaAs quantum nanostructures

ศ. ดร. สมศกั ด์ิ ปญ ญาแกว ภาควช� าวศ� วกรรมไฟฟา
0-2218-6524 Email: [email protected]

ABSTRACT

InSb/GaAs nanostructures grown by solid-source molecular beam epitaxy are
investigated in this work. Three-dimensional dot-like InSb nanostructure are obtained
by self-assembled growth at relatively low growth temperatures (250–300 °C) with
slow InSb growth rate. Nanostructure base is typically elongated. Facet analysis of
the free-standing InSb nanostructure grown at 250 °C shows that each nanostructure
has flat top (001) surface while side facets are along <11n> directions. In contrast,
InSb nanostructures grown at higher temperature show rather smooth surfaces.
Analysis of their size distributions shows that the size inhomogeneity increases with
the growth temperature. Moreover, Raman spectroscopy reveals both InSb-related
peaks at 181 and 189 cm−1 and GaAs-related peaks at 268 and 293 cm−1. Raman
spectroscopy with different excitation wavelengths is applied to probe residual
strain in subsurface GaAs layer.

FULL PAPER (LINK)

ดูเพ่มิ เติมไดท ่วี ารสาร
Journal of Crystal Growth
ตพี ิมพป  2017 เดอื นพฤศจิกายน ฉบบั ที่ 477 หนา 30-33

https://www.sciencedirect.com/science/article/pii/S0022024817300179

หนว ยสอ่ื สารองคก ร [email protected]

Differential form of Bivariate MMSE
estimator based on Gaussian noise

รศ. ดร.เจษฎา ชินรุง เร�อง ภาควช� าวศ� วกรรมไฟฟา
0-2218-6906 [email protected]

ABSTRACT

In fact, the noise signal is an important problem in signal, circuits and
systems. The minimum mean square error (MMSE) estimation technique
is useful in several additive white Gaussian noise (AWGN) reduction
methods. Original form of MMSE estimator is the integral form. Unfortu-
nately, integral form of MMSE estimator cannot be obtained in simple
form for any interesting peaked, heavy-tailed densities (also known as
super-Gaussian densities). In this work, we proposed a differential form
of bivariate MMSE estimator. The development depends on bivariate
Taylor series. The proposed estimator requires no integration. In fact, the
derivation is an extension of the existing results for differential form of
univariate MMSE estimator. © World Scientific Publishing Company.

FULL PAPER (LINK)

ดูเพมิ่ เตมิ ไดท่ีวารสาร
Journal of Circuits, Systems and Computers
ตีพิมพป 2017 เดอื นมกราคม ฉบบั ท่ี 26 Article number 1750008
https://www.worldscientific.com/doi/abs/10.1142/S0218126617500086

หนว ยสอ่ื สารองคก ร [email protected]

Motion-resistant pulse oximetry
processing based on time-frequency
analysis

รศ. ดร.เจษฎา ชินรงุ เร�อง ภาคว�ชาว�ศวกรรมไฟฟา
0-2218-6906 [email protected]

ABSTRACT

This paper proposes an alternative method for pulse oximetry processing based on
time-frequency analysis. Instead of using the fast Fourier transform (FFT), the continuous
wavelet transform (CWT) together with the median calculation was proposed for finding the
frequency components of the normalized first derivative red and infrared photoplethysmo-
graphic signals (PPG). In order to estimate the arterial oxygen saturation (%SpO2), the ratio of
each red CWT modulus to each corresponding infrared CWT modulus was computed at each
frequency, and then converted to the oxygen saturation by using the saturation equation
obtained from calibration. All of the oxygen saturation data were plotted on a histogram. The
greatest oxygen saturation with the most occurrences was considered to represent the
%SpO2. The experiments were held to evaluate the performance of the proposed processing
method compared with the conventional pulse oximetry (CPO) processing. The red and infra-
red PPGs were acquired from left and right index fingers simultaneously by using the PPG
measurement system constructed in the laboratory. During measurement, the left index finger
was stationary, while the right index finger was performed the finger bend to induce the
motion artifact (MA) in transient and periodic manners. All detected PPGs were processed by
the proposed method and the CPO processing. The %SpO2 obtained from different processing
methods and positions were compared. Experimental results showed that the proposed
method was more resistant to the MA than the conventional method.

FULL PAPER (LINK)

ดเู พ่มิ เตมิ ไดท ่ีวารสาร
Engineering Journal
ตีพมิ พป  2017 เดอื นธันวาคม ฉบับที่ 21 หนา 181-196
http://www.engj.org/index.php/ej/article/view/1549/675

หนว ยสอ่ื สารองคก ร [email protected]

A novel approach for centralized 3D radio
resource allocation and scheduling in dense
HetNets for 5G control-/user-plane separation
architectures

รศ. ดร.เชาวนดิศ อัศวกุล ภาคว�ชาวศ� วกรรมไฟฟา
0-2218-6908 [email protected]

ABSTRACT

This paper presents a centralized 3-dimensional radio resources (namely, time, frequency, and power)
allocation and scheduling approach for control-plane and user-plane (C-/U-plane) separation architectures for
fifth generation mobile networks. A central station is considered where schedulers of all base stations (BSs) are
located. We consider a multi-tier network that comprises of a macrocell BS (MCBS), several outdoor picocell
BSs, and a number of indoor femtocell BSs (FCBSs) deployed in a number of multi-storage buildings. The
system bandwidth is reused in FCBSs within each building orthogonally. In contrast to the conventional almost
blank subframe, we consider a fully blank subframe based time-domain enhanced intercell interference coor-
dination to split completely C-/U-plane traffic such that the control-plane can be served only by the MCBS and
the user-plane of user equipments by their respective BSs. We propose two power management schemes for
FCBSs based on whether or not the coordinated multi-point communication with joint transmission (JT CoMP)
is employed during off-state of a FCBS and develop a power control mechanism for both a single user and
multi-user per FCBS scenarios. An optimal value of average activation factor (OAF) for a FCBS is derived to
trade-off its serving capacity and transmit power saving factor. It is shown that in order to improve the network
capacity, a FCBS needs to operate at an average activation factor (AAF) greater than its OAF using JT CoMP to
serve neighboring on-state FCBSs during its normal off-state, whereas at an AAF less than the OAF to improve
the energy efficiency. With a system level simulation, we show that the capacity of a FCBS increases, whereas
its power saving factor decreases linearly with an increase in its AAF because of serving increased traffic, and
an OAF of 0.5 for the capacity scaling factor κ = 1/2 and greater than 0.5 for κ < 1 are found.

FULL PAPER (LINK)

ดูเพิม่ เติมไดที่วารสาร
Engineering Journal
ตพี มิ พป 2017 เดอื นกรกฎาคม ฉบบั ที่ 21 หนา 287-305
http://www.engj.org/index.php/ej/article/view/1606/604

หนว ยสอ่ื สารองคก ร [email protected]

A tractable analytical model for
interference characterization
and minimum distance enforcement
to reuse resources in
three-dimensional in-building
dense small cell networks

รศ. ดร.เชาวนด ศิ อัศวกลุ ภาควช� าว�ศวกรรมไฟฟา
0-2218-6908 [email protected]

ABSTRACT

In this paper, we address mainly 2 important issues, namely, characterizing co‐channel
interference and enforcing a minimum distance between femtocell base stations (FCBSs)
for reusing resources in FCBSs deployed in a 3‐dimentional multi‐floor building. Each floor
is modeled as a group of square‐grid apartments, with one FCBS per apartment.
We propose a simple yet reasonable analytical model by using planar‐Wyner model for
intra‐floor interference and linear‐Wyner model for inter‐floor interference modeling in a
3‐dimensional multi‐floor building to derive a minimum distance between co‐channel
FCBSs for optimization constraints, namely, link level interference, spectral efficiency, and
capacity. As opposed to orthogonal resource reuse and allocation (ORRA) where resources
are reused once, using the proposed model, we develop 2 strategies for reusing resources
more than once, that is, non‐ORRA, within a multi‐floor building. An algorithm of the
proposed model is developed by including an application of the model to an ultra‐dense
deployment of multi‐floor buildings. With an extensive numerical analysis and system level
simulation, we demonstrate the capacity outperformance of non‐ORRA over ORRA by
manifold. Further, with a fairly accurate yet realistic estimation, we show that the expected
spectral efficiency of fifth‐generation networks can be achieved by applying the proposed
model to an ultra‐dense deployment of FCBSs.

FULL PAPER (LINK)

ดเู พม่ิ เตมิ ไดทีว่ ารสาร
International Journal of Communication Systems
ตีพมิ พป 2017 เดือนกรกฎาคม ฉบบั ที่ 30 หมายเลขบทความ e3240
https://onlinelibrary.wiley.com/doi/abs/10.1002/dac.3240

หนว ยสอ่ื สารองคก ร [email protected]

Closed-form multiclass cell
transmission model enhanced
with overtaking, lane-changing,
and first-in first-out properties

รศ.ดร.เชาวนดิศ อศั วกุล ภาควช� าวศ� วกรรมไฟฟา
0-2218-6908 Email: [email protected]

ABSTRACT

A novel multiclass macroscopic model is proposed in this article. In order to enhance
first-in, first-out property (FIFO) and transmission function in the multiclass traffic
modeling, a new multiclass cell transmission model with FIFO property (herein called
FM-CTM) is extended from its prior multiclass cell transmission model (M-CTM). Also, to
enhance its analytical compactness and resultant computational convenience,
FM-CTM is formulated in this paper as a set of closed-form matrix equations. The
objetive is to improve the accuracy of traffic state estimation by enforcing FIFO propety
when a fast vehicle cannot overtake a slow vehicle due to a limitation of a single-lane
road. Moreover, the proposed model takes into account a different priority for vehicles
of each class to move forward through congested road conditions, and that makes the
flow calculation independent from their free-flow speeds. Some hypothetical and
real-world freeway networks with a constant or varying number of lanes are selected to
verify FM-CTM by comparing with M-CTM and the conventional CTM. Observed
densities of VISSIM and real-world dataset of I-80 are selected to compare with the
simulated densities from the three CTMs. The numerical results show that FM-CTM
outperforms the other two models by 15% of accuracy measures in most cases.
Therefore, the proposed model is expected to be well applicable to the road network
with a mixed traffic and varying number of lanes.

FULL PAPER (LINK)

ดเู พมิ่ เติมไดท ว่ี ารสาร
Transportation Research Part C: Emerging Technologies
ตีพิมพป 2017 เดอื นธนั วาคม ฉบับที่ 85 หนา 86-110
https://www.sciencedirect.com/science/article/pii/S0968090X17302486

หนว ยสอ่ื สารองคก ร [email protected]

Development of real-time interworking
between IEEE1888 and ECHONET lite
standards for building energy
management system

รศ. ดร.เชาวนดศิ อศั วกลุ ภาควช� าวศ� วกรรมไฟฟา
0-2218-6908 [email protected]

ABSTRACT

This paper proposes the development of interworking proxy gateway
for real-time data updates between IEEE1888 and ECHONET Lite standards
in a building energy management system. Both IEEE1888 and ECHONET
Lite are developed as open standards and hence a support for application
and equipment development. IEEE1888 standard uses XML message
format and is suitable for a wide range of machine-to-machine communi-
cations. ECHONET Lite standard is a highly accepted standard in Japan and
with emerging supports by equipment manufacturers such as for air con-
ditioners. This development of interworking proxy gateway in this research
thus enhances the ability and flexibility in building energy management
system to be compliant with different communication standards, which
could be useful for both user and manufacturer sectors in the future.

FULL PAPER (LINK)

ดูเพม่ิ เตมิ ไดท่ีวารสาร
Engineering Journal
ตพี ิมพป 2017 เดอื นตุลาคม ฉบับท่ี 21 หนา 1-10
http://engj.org/index.php/ej/article/view/2175/653

หนว ยสอ่ื สารองคก ร [email protected]

Impact Analysis of Start-Up Lost Time
at Major Intersections on Sathorn Road
Using a Synchro Optimization and a
Microscopic SUMO Traffic Simulation

รศ. ดร.เชาวนดิศ อศั วกลุ ภาควช� าวศ� วกรรมไฟฟา
0-2218-6908 [email protected]

ABSTRACT

Start-up lost time is the time lost in the starting of the green time interval when a traffic
signal phase changes from red to green and previously stopped vehicles in the curb line
queue need time to accelerate to the desired speed. Actual traffic data analytics from newly
installed loop coil detectors at all approaching upstream road segments of major
intersections on Sathorn Road in Bangkok, Thailand, are used to confirm that the vehicle
flow is obstructed considerably by the large start-up lost time. In this paper, the effect of
a large start-up lost time is evaluated in terms of the travel time of passenger cars in
a calibrated microscopic traffic simulation. The evaluation is based on the simulation of the
urban mobility platform, while the traffic signal lights at major intersections are based on the
standard Synchro optimization software. By the simulation, the average travel time
per vehicle increases from 4% to 37% when the start-up lost time is varied from a baseline
value of 1 s to the maximum value of 15 s, which potentially occurred in the actual traffic
data collection in this paper. In addition, the optimal traffic signal green phase lengths
increase from 2% to 42%, depending on the volume-to-capacity ratio. The similar increasing
trend of optimal green time and average travel time per vehicle is observed using theoretical
analysis based on M/M/1 and D/D/1 queues to support the results from Synchro. Findings of
this paper are beneficial for understanding the impact of start-up lost time at signalized
intersections.

FULL PAPER (LINK)

ดูเพม่ิ เติมไดทวี่ ารสาร
IEEE Access
ตพี ิมพป 2017 เดือนสงิ หาคม ฉบับท่ี 6 หนา 6327-6340
https://ieeexplore.ieee.org/document/8010263/

หนว ยสอ่ื สารองคก ร [email protected]

Incentive and Architecture of Multi-Band
Enabled Small Cell and UE for
Up-/Down-Link and Control-/User-Plane
Splitting for 5G Mobile Networks

รศ. ดร.เชาวนดิศ อัศวกุล ภาควช� าว�ศวกรรมไฟฟา
0-2218-6908 [email protected]

ABSTRACT

In this paper, a multi-band enabled femtocell base station (FCBS) and user equipment (UE) architecture is
proposed in a multi-tier network that consists of small cells, including femtocells and picocells deployed over the
coverage of a macrocell for splitting uplink and downlink (UL/DL) as well as control-plane and user-plane
(C-/U-plane) for 5G mobile networks. Since splitting is performed at the same FCBS, we define this architecture as the
same base station based split architecture (SBSA). For multiple bands, we consider co-channel (CC) microwave and
different frequency (DF) 60 GHz millimeter wave (mmWave) bands for FCBSs and UEs with respect to the microwave
band used by their over-laid macrocell base station. All femtocells are assumed to be deployed in a 3-dimensional
multi-storage building. For CC microwave band, cross-tier CC interference of femtocells with macrocell is avoided
using almost blank subframe based enhanced inter-cell interference coordination techniques. The co-existence of
CC microwave and DF mmWave bands for SBSA on the same FCBS and UE is first studied to show their performance
disparities in terms of system capacity and spectral efficiency in order to provide incentives for employing multiple
bands at the same FCBS and UE and identify a suitable band for routing decoupled UL/DL or C-/U-plane traffic. We
then present a number of disruptive architectural design alternatives of multi-band enabled SBSA for 5G mobile
networks for UL/DL and C-/U-plane splitting, including a disruptive and complete splitting of UL/DL and C-/U-plane
as well as a combined UL/DL and C-/U-plane splitting, by exploiting dual connectivity on CC microwave and DF
mmWave bands. The outperformances of SBSA in terms of system level capacity, average spectral efficiency, energy
efficiency, and control-plane overhead traffic capacity in comparison with different base stations based split archi-
tecture (DBSA) are shown. Finally, a number of technical and business perspectives as well as key research issues of
SBSA are discussed.

FULL PAPER (LINK)

ดเู พมิ่ เตมิ ไดทวี่ ารสาร
Frequenz
ตพี มิ พป 2017 เดือนมกราคม ฉบบั ท่ี 71 หนา 95-118
https://www.degruyter.com/view/j/freq.2017.71.issue-1-2/-
freq-2016-0014/freq-2016-0014.xml

หนว ยสอ่ื สารองคก ร [email protected]