A Study on Factor that Effect on Consumer’s Behaviour on Cross-Border E-Commerce in Vietnam - Ho Chi Minh City

Dao,Duy Thang,Hyun,In-Gyou 한국유통과학회 2019 KODISA ICBE (International Conference on Business Vol.2019 No.-

Vietnam E-commerce has been used and developed 10 years ago but recently, with removing tariff barriers, Vietnam’s customer can easily buy almost thing in the foreign web-site. However, little research has been done to study how to customer’s using intention on across national borders. This study aims to find the factors that effect to customer’s using intention on foreign direct online shopping. A conceptual model is developed from the perspectives of customer’s trust and value. We also examine the impact of information’s signal, security and safe, country image on customer’s trust, as well as the impact of benefits, innovation, cost on customer’s perceived value. This study use an online survey to make questionnaire about the factor and use the answer to test the research model. Our findings can help researchers and practitioners understand the barriers and behaviour of Ho Chi Minh City’s customers to cross-border e-commerce and devise strategies to make profit.

Influence of Rain Gauge Density and Temporal Resolution on the Performance of Conditional Merging Method

Dao,Duc Anh,Kim,Soohyun,Kim,Tae-Woong,Kim,Dongkyun 한국방재학회 2019 한국방재학회논문집 Vol.19 No.6

본 연구는 in-situ 강우자료와 레이더자료를 병합하는 조건부 합성(CM)기법의 성능 평가를 목표로 한다. 합성방법은 다음 단계를 통해 처리된다. (1) 정규 크리깅(OK) 기법은 관측소와 레이더 기반 크리깅 강우장을 얻기 위해 적용한다. (2) 보정 강우장은 원래 레이더 강우장에서 레이더기반 크리깅 강우장의 차로 계산한다. (3) 합성강우량은 관측소기반 크리깅 강우장에 보정 강우장을 더하여 도출한다. 분석결과는 CM기반 강우장이 조사된 모든 33개의 10분 강우장 중 22개 사례에 대해 관측소기반 강우장보다 더 정확한 것으로 나타났다. CM 방법과 관측소기반 OK기법의 상관계수는 각각 0.63과 0.83 그리고 0.01과 0.74 사이 값을 보인다. 두 방법의 성능은 관측소 밀도가 높고 시간해상도가 낮을수록 향상되었다. OK기법의 성능은 관측소 밀도에 더 민감하고, CM 기법의 성능은 시간해상도에 더 민감한 것으로 나타났다. 또한, 기존 관측소 밀도가 100 km2 당 1개 일 때, 관측소를 추가하면 두 방법의 성능이 크게 향상되었다. 관측소 증가에 의한 강우량 측정 개선 정도는 관측소 개수가 100 km2 당 4개 이상에 도달할 시 효과가 미미한 것으로 나타났다. This study aims to evaluate the performance of conditional merging (CM) technique to merge radar and in-situ rain gauge data. The merging method contains the following steps: (1) the ordinary kriging(OK) technique is applied to obtain the gauge-only and radar-only kriged rainfall fields; (2) the correction field is calculated by subtracting the radar-only kriged rainfall field from the original radar field; (3) the composite rainfall is derived by adding the correction field to the gauge-only kriged field. We investigated 33 10-min rainfall fields; there were 22 instances where the CM-based rainfall fields were more accurate than the gauge-only fields. The correlation coefficients of the CM and the gauge-only OK methods varied between 0.63 and 0.83, and 0.01 and 0.74 respectively. The performance of both methods improved with greater gauge density and coarser temporal resolution. Furthermore, the OK and CM techniques’performances were more sensitive to gauge density and temporal resolution respectively. We also found that the addition of gauge significantly improved the performance of both methods when the existing gauge density is approximately 1 gauge/100 km2. However, this effect is absent when the density reaches 4 gauges/100 km2.

Ultrasonic Vibration Assisted Cutting of Nomex Honeycomb Core Materials

Dao‑Hui Xiang,Bang‑Fu Wu,Yun‑Long Yao,Bo Zhao,Jin‑Yuan Tang 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.1

Nomex honeycomb core materials have been widely used in the aviation industry due to their special structure and performance. Conventional high-speed machining have resulted in the poor machinability of the honeycomb core so that the ultrasonic machining technology was applied. The kinematic characteristics in the ultrasonic vibration assisted cutting process were analyzed according to the movement of the sharp tool. Based on slide effect, a cutting force model was proposed to study the relationship between cutting parameters and cutting force. Ultrasonic vibration assisted cutting and ordinary cutting tests of Nomex honeycomb core material were conducted by considering feed rate, the inclined angle and the deflected angle. Besides, the effects of cutting parameters on machined surface quality of honeycomb core wall were studied. The test results show that slide effect caused by ultrasonic vibrations can reduce cutting resistance compared with ordinary cutting. The developed cutting force model can be applied to evaluated the cutting force in the ultrasonic vibration assisted cutting of Nomex honeycomb core material. The inclined angle has a great influence on the cutting force during ultrasonic vibration assisted cutting. High-speed reciprocating sliding action can effectively cut aramid fibers so that burrs and tearing defects of the incision have been greatly improved under condition of ultrasonic vibration assisted cutting.

당송(唐宋)시기 도통(道統)내용의 전환 -당말(唐末)에서 북송(北宋)시기 도의 전승 내용에 관한 담론을 중심으로-

임명희 ( Myung Hee Lim ) 한국철학사연구회 2013 한국 철학논집 Vol.0 No.36

住居移動의 理念的 모델 定立

韓大鉉 강릉대학교 영동산업문제연구소 1985 産經論叢 Vol.4 No.-

Stewardship Theory and Information on Family Firm Performance in Vietnam

Thi Thanh Binh DAO(Thi Thanh Binh DAO ),Linh Chi HOANG(Linh Chi HOANG ) 한국유통과학회 2022 유통과학연구 Vol.20 No.12

Purpose: The paper contributes to the existing literature on Vietnamese corporate governance and firm performance with a focus on listed family firms and the use of a more suitable econometric framework to analyze firm performance. The study investigates how family firm performance is affected by corporate governance under the standpoint of stewardship theory in Vietnam. Research design, data and methodology: With the use of different measures for firm performance (Tobin’s Q, ROA, and ROE), regression models were estimated using Generalized Least Square (GLS) method on a panel data of a total of 113 listed companies during the five-year period from 2015 to 2019. Results: We found that family ownership as the main characteristic of the stewardship theory affects family firms positively. In addition, several other characteristics in corporate governance as board composition (board independence, board audits, and board committees), CEO (age and tenure) and firm characteristics (size, age, expansion, and annual sales) showed significant impacts on firm performance. Our findings also suggest that family firm performance can be either positively or negatively affected based on the characteristics of corporate governance. The findings can help companies evaluate the significance of corporate governance through deciding board structure and the selection of CEOs to match family firm characteristics. It also gives insights for investors, rating agencies, and policymakers for relevant purposes.

Pt-NP–MWNT nanohybrid as a robust and low-cost counter electrode material for dye-sensitized solar cells

Dao, Van-Duong,Ko, Seung Hyeon,Choi, Ho-Suk,Lee, Joong-Kee The Royal Society of Chemistry 2012 Journal of materials chemistry Vol.22 No.28

<P>Pt-NPs hybridized inside and outside multi-walled carbon nanotubes (MWNTs) were successfully synthesized using a liquid plasma system with 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide under atmospheric pressure. The Pt-NPs with a size of 3–4 nm were stably and uniformly hybridized on both inner and outer surfaces of the MWNTs. The nanohybrid materials were applied to the counter electrode of dye-sensitized solar cells (DSCs). Electrochemical impedance measurement of DSCs revealed that the charge-transfer resistance of a MWNT–Pt nanohybrid-coated electrode was less than that of Pt-sputtered and MWNT-coated electrodes. Due to the low charge-transfer resistance, the DSC exhibited fairly improved energy conversion efficiency compared to the DSCs equipped with Pt-sputtered and MWNT-coated counter electrodes.</P> <P>Graphic Abstract</P><P>Pt-NPs immobilized both inside and outside of the MWNTs show ultra high stability as well as excellent photovoltaic performance as a counter electrode of DSC. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2jm31332d'> </P>

Optimum strategy for designing a graphene-based counter electrode for dye-sensitized solar cells

Dao, V.D.,Larina, L.L.,Suh, H.,Hong, K.,Lee, J.K.,Choi, H.S. Pergamon Press ; Elsevier Science Ltd 2014 Carbon Vol.77 No.-

In this study, we developed a cost-effective method to enhance the electro-catalytic activity and conductivity of graphene-based counter electrodes (CEs) by diminishing the oxygen content in graphene nanoplatelets (GNPs) through dry plasma reduction (DPR). As a result, the efficiency of dye-sensitized solar cells (DSCs) based on GNPs with an average surface area of 750m<SUP>2</SUP>/g treated by DPR was enhanced by 15% over that of devices with pristine graphene oxide electrodes. The next step in the design strategy for improving DSC performance suggested the immobilization of platinum nanoparticles (PtNPs) on the electrode surface through DPR. DSCs based on the newly developed CEs had an increase in efficiency by 50.3% over that of the Pt-free device, and by 10.4% over the efficiency of state-of-the-art DSCs. The introduction of PtNPs on the surface of a CE through DPR along with removal of the oxygen functional groups from the surface of the GNP electrode reduces the charge-transfer resistance at the electrolyte/CE interface and the diffusion impedance of triiodide ions. PtNPs hybridization on the surface of CE facilitates the electron conductivity in the PtNPs/CE structure by creating a conductive network in the sp<SUP>3</SUP> phase for charge carriers delocalized in a sp<SUP>2</SUP> matrix.

Graphene-based nanohybrid materials as the counter electrode for highly efficient quantum-dot-sensitized solar cells

Dao, Van-Duong,Choi, Youngwoo,Yong, Kijung,Larina, Liudmila L.,Choi, Ho-Suk Elsevier 2015 Carbon Vol.84 No.-

<P><B>Abstract</B></P> <P>Dry plasma reduction is an excellent approach for easily and uniformly immobilizing Pt, Au and bimetallic AuPt nanoparticles (NPs) on a graphene nanoplatelets (GC)-coated layer under atmospheric pressure at a low temperature and without using any toxic reductants. The NPs with an average size of about 2nm were stably and uniformly hybridized on the surface of reduced graphene nanoplatelets (RGC) after co-reduction of metal precursor ions and GC to metal atoms and RGC, respectively. Quantum-dot-sensitized solar cells exploiting AuNP/RGC, PtNP/RGC and bimetallic AuPtNP/RGC counter electrodes (CEs) exhibited power conversion efficiencies of 2.7%, 3.0% and 4.5%, respectively. The efficiencies are comparable to that of device with a conventional Au-sputtered CE (3.6%). The effect is ascribed to high electrochemical catalytic activity and high electrical conductivity of developed nanohybrid materials.</P>

Differentiation Potential and Profile of Nuclear Receptor Expression During Expanded Culture of Human Adipose Tissue-Derived Stem Cells Reveals PPARγ as an Important Regulator of <i>Oct4</i> Expression

Dao, Lan T.M.,Park, Eun-Young,Hwang, Ok-Kyung,Cha, Ji-Young,Jun, Hee-Sook Mary Ann Liebert 2014 STEM CELLS AND DEVELOPMENT Vol.23 No.1