A Simple Method of Electrospun Tungsten Trioxide Nanofibers with Enhanced Visible-Light Photocatalytic Activity

Ofori, Frank Agyemang,Sheikh, Faheem A.,Appiah-Ntiamoah, Richard,Yang, Xinsheng,Kim, Hern Springer Berlin Heidelberg 2015 Nano-micro letters Vol.7 No.3

<P>The present study involves the fabrication of tungsten trioxide (WO<SUB>3</SUB>) nanofibers by an electrospinning technique using polyvinyl pyrrolidone (PVP)/citric acid/tungstic acid as precursor solution. It was found that the PVP concentration was one of the most crucial processing parameters determining the final properties of WO<SUB>3</SUB> nanofibers. The optimum concentration of PVP was from 75 to 94 g L<SUP>−1</SUP>. The average diameter of the nanofibers increases with increasing the PVP concentration, whereas it is decreased after sintering and orthorhombic structure were formed at 500 °C. The photocatalytic properties of the as-synthesized nanofibers were also investigated by degrading methylene blue and twofold efficiency was obtained compared with that of commercial WO<SUB>3</SUB> microparticles.</P>

What makes people purchase used products online using C2C used product platform?

Henry Ofori 한국지능정보시스템학회 2022 한국지능정보시스템학회 학술대회논문집 Vol.2022 No.6

What Makes People Purchase Used Products Online? Focusing on the Roles of Consumer Value, Platform Attachment, and Consumer Engagement

Henry Ofori(헨리 오포리),Juyoung Kang(강주영),Sung-Byung Yang(양성병) 한국경영학회 2023 經營學硏究 Vol.52 No.5

Consumer-to-consumer (C2C) platforms have seen tremendous growth recently with most studies focusing on C2C platform for ridesharing and accommodation. However, little studies have explored C2C platform for used product transaction and the relevant factors that influence its continuous usage and recommendation. This study explores how consumer value serves as an antecedent of consumer engagement and platform attachment, leading to continuous use and recommendation intentions of C2C used-product platforms through the lens of uses and gratification theory. Analyzing the structural equation model with survey responses from experienced users of C2C used-product platforms reveals that multi-dimensional consumer values significantly influence consumer engagement and platform attachment. Consumer engagement is observed to substantially impact continuous use intention and recommendation intention of C2C used-product platforms. In contrast, platform attachment significantly affects only recommendation intention. A multi-group analysis, however, shows that platform type (i.e., community-based connector vs. supportive models) does not moderate the strength of the relationship between the exogenous and endogenous constructs of the research model. The results raise a favorable theoretical implication for future and practical implications for C2C used product and e-commerce firms.

Ricardian Equivalence Hypothesis in the Sub-Sahara African Countries

( Grace Ofori-abebrese ),( Robert Becker Pickson ) 세종대학교 경제통합연구소 2018 Journal of Economic Integration Vol.33 No.3

The validity of the Ricardian equivalence proposition remains disputed in spite of the numerous empirical studies. This study utilized panel ARDL estimation approach to investigate the evidence of Ricardian Equivalence Hypothesis in five Sub-Sahara African countries, namely Botswana, Ghana, Gambia, Nigeria, and Kenya over the period of 1981~2014. The results show that GDP per capita and interest rate have significant positive impacts on private consumption, whereas government debt, government spending, and government interest payment on the outstanding debt have negative impacts on private consumption. From the perspective of this study, the Ricardian equivalence hypothesis, which states that private consumption remains unchanged regardless of government’s spending, does not hold in Sub-Sahara African countries.

Cadmium Contents of Soils and Cocoa Beans from Ghana

Kwasi Ofori-Frimpong 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

A Study on Secrecy Capacity in the Presence of Multiple Eavesdropper Attacks on Wireless Channels

Kwadwo Boateng Ofori-Amanfo,Kyoung-Jae Lee 한국통신학회 2018 한국통신학회 학술대회논문집 Vol.2018 No.1

Electrospun carbon nanofiber-carbon nanotubes coated polyaniline composites with improved electrochemical properties for supercapacitors

Agyemang, Frank Ofori,Tomboc, Gracita M.,Kwofie, Samuel,Kim, Hern Elsevier 2018 ELECTROCHIMICA ACTA Vol.259 No.-

<P><B>Abstract</B></P> <P>The carbon nanofiber-carbon nanotube (CNF-CNT) composites were fabricated by simple electrospinning and carbonization of polyacrylonitrile (PAN)-CNT solution prepared by first sonicating and stirring the CNT in N, N-dimethylformamide (DMF) as solvent. Aniline monomer was then coated on the composite materials via in situ chemical polymerization to form CNF-CNT-PANI composite. The as-prepared samples were then characterized. Importantly, the dispersed CNTs in the CNF-CNT composites were crucial for the CNF-CNTs acting as supports for the CNF-CNT-PANI composites to attain high electrochemical properties. The composite electrode material is found to be used as effective electrode material for supercapacitors with specific capacitance as high as 1119 F g<SUP>−1</SUP>at 1 A g<SUP>−1</SUP> compared to the bare CNF film with a specific capacitance of 278 F g<SUP>−1</SUP>. The composite electrode displaced excellent cyclic stability with retention of 98% even after 2000 cycles at a current density of 10 A g<SUP>−1</SUP>.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Primary Analysis of Information Distribution at Walkbase Company: Developing an Information Strategy

Hamed Ahmadinia,Muhaimin Karim,Edward Ofori 한국유통과학회 2015 The Journal of Industrial Distribution & Business( Vol.6 No.4

Purpose Currently, organizations – must have a plan to achieve their future objectives. In this case, an information strategy facilitates greater success when planning for the future in any organization. Research design, data, and methodology – The core objective of the project was to explore the information infrastructure of Walkbase in a discursive manner. We started the project by providing a description of the firm, which facilitates retail outlets using in-store analytical devices. Results – We conclude that the management of Walkbase revised its current information structure to implement a more structured one that might be included in a long-term investment. On such an occasion, management can prioritize the component to develop first. Conclusions – Along with our results, we also described the business, its products, its facilities, and how it can serve different industries. Finally, we left the prioritization decision within the framework’s components to top management.

중고의류 소비가치가 제품 평가기준과 구매의도에 미치는 영향: 한국과 가나의 국가간 비교 분석

장영용,최희정,Ofori, Henry,한상린 글로벌경영학회 2022 글로벌경영학회지 Vol.19 No.3

Despite the situation where fashion companies are struggling due to the COVID-19 pandemic, the global secondhand clothes market is showing remarkable growth. In line with this global trend, Korea's exports of secondhand clothes are steadily increasing. Unlike previous studies that have focused only on the domestic market, this study analyzed the impact of consumption values of secondhand clothes through comparative studies between countries. Ghana, a major gateway to West Africa, is an important importer of secondhand clothes and a developed brokerage trade that re-exports secondhand clothes to neighboring countries. The purpose of this study is to compare the differences between Korea and Ghana in the impact of the consumption value of secondhand clothes on the evaluation criteria and purchase intention. The results confirmed that the impact of consumption values of secondhand clothes on evaluation criteria and purchase intention differed between countries. In Korea, all three dimensions of the consumption values had direct and indirect effects, but in Ghana, environmental and functional values were only indirectly connected to purchase intention through evaluation criteria. 코로나 19 팬데믹으로 인하여 패션기업들이 어려움을 겪고 있는 상황에도 불구하고 전 세계 중고의류 시장은 괄목할만한 성장을 보이고 있다. 이러한 글로벌 트렌드 속에서 한국의 중고의류 해외수출도 지속적으로 성장하고 있다. 본 연구는 지금까지 국내시장에 포커스를 맞춘 선행연구와는 달리 국가 간 비교연구를 통하여 중고의류 소비가치의 영향을 분석함으로써 글로벌 패션시장을 공략하기 위한 중요한 기초자료를 제시하고자 하였다. 가나는 서부 아프리카의 주요 관문으로써 중고의류의 중요한 수입국인 동시에 주변국으로 중고의류를 재수출하는 중고의류 중개무역이 발달한 국가이며, 한국의 대가나 수출품 중 중고의류가 높은 비중을 차지할 만큼 중고의류의 중요한 교역국이라고 할 수 있다. 본 연구에서는 한국과 가나의 소비자들을 대상으로 중고의류 소비가치가 제품 평가기준과 구매의도에 어떠한 영향을 미치는지 그 차이를 알아보고, 글로벌 패션 시장에서 중고의류 소비가치와 관련된 소비자 행동의 이론적 및 실무적 시사점을 제공하고자 하였다. 선행연구에서 신뢰도가 타당도가 검증된 측정 문항을 통하여 설문지가 개발되었으며, 데이터는 한국과 가나에서 중고의류를 구매한 경험이 있는 소비자들로부터 수집하였다. 본 연구의 분석결과 중고의류 소비가치가 제품 평가기준과 구매의도에 미치는 영향은 국가간 차이에 따라 달라질 수 있음을 확인하였다. 한국에서는 중고의류 소비가치의 세 가지 차원 모두가 직간접적으로 다양한 영향을 미쳤으나, 가나에서는 환경적 가치와 기능적 가치가 제품평가 기준을 통해서 간접적으로만 구매의도로 연결되어 차이를 보였다.

Ambidextrous Leadership and Innovative Work Behavior:Evidence from South Korea Semiconductor Industry

Henry Ameyaw Domfeh,Henry Ofori,윤소라,강주영 한국IT서비스학회 2023 한국IT서비스학회지 Vol.22 No.3

The semiconductor industry is a competitive, complicated and a cyclical sector with a highly dynamic business climate which requires an effective leadership style to operate and succeed. This study explores the important issue of how leadership facilitates employee innovative work behaviors in the semiconductor industry. Based on the assumptions of the ambidextrous leadership theory and social exchange theory, we collected data from 300 workers employed in the semiconductor industry of South Korea. The study investigated (1) the impact of ambidextrous leadership on innovative work behavior, (2) the mediating effects of workers decision-making autonomy and workplace learning in the relationship between ambidextrous leadership and innovative work behavior, (3) the moderating role of resistance to change in the relationship between ambidextrous leadership and workplace learning, and (4) the moderating role of openness to experience in the relationship between ambidextrous leadership and innovative work behavior. SmartPLS 4 and SPSS v24 was used to analyze our data. The study revealed that ambidextrous leadership positively influences workers innovative work behavior. In addition, decision-making autonomy and workplace learning partially mediated the relationship between ambidextrous leadership and innovative work behavior. Moreover, resistance to change was found to be a significant moderator in the relationship between ambidextrous leadership and workplace learning. Based on these findings, we conclude that ambidextrous leadership is very imperative for semiconductor businesses seeking to foster employee innovative work behaviors. Theoretical and practical implications of the study are also discussed.