• Steel and Composite Structures
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• 제44권2호
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• pp.155-169
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• 2022

In the present paper an analytical model was developed to study the non-linear vibrations of Functionally Graded Carbon Nanotube (FG-CNT) reinforced doubly-curved shallow shells using the Multiple Scales Method (MSM). The nonlinear partial differential equations of motion are based on the FGM shallow shell hypothesis, the non-linear geometric Von-Karman relationships, and the Galerkin method to reduce the partial differential equations associated with simply supported boundary conditions. The novelty of the present model is the simultaneous prediction of the natural frequencies and their mode shapes versus different curvatures (cylindrical, spherical, conical, and plate) and the different types of FG-CNTs. In addition to combining the vibration analysis with optimization algorithms based on the genetic algorithm, a design optimization methode was developed to maximize the natural frequencies. By considering the expression of the non-dimensional frequency as an objective optimization function, a genetic algorithm program was developed by valuing the mechanical properties, the geometric properties and the FG-CNT configuration of shallow double curvature shells. The results obtained show that the curvature, the volume fraction and the types of NTC distribution have considerable effects on the variation of the Dimensionless Fundamental Linear Frequency (DFLF). The frequency response of the shallow shells of the FG-CNTRC showed two types of nonlinear hardening and softening which are strongly influenced by the change in the fundamental vibration mode. In GA optimization, the mechanical properties and geometric properties in the transverse direction, the volume fraction, and types of distribution of CNTs have a considerable effect on the fundamental frequencies of shallow double-curvature shells. Where the difference between optimized and not optimized DFLF can reach 13.26%.

• 아태비즈니스연구
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• 제12권2호
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• pp.205-222
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• 2021

Purpose - Due to the Covic-19 pandemic, the perceived value of video conferencing platforms has been increased drastically. However, there is little guidance on how service providers can improve video conferencing platforms. The purpose of this study is to investigate the factors that influence the users' perceived value of video conferencing services based on the heuristic-systematic model and the value-based adoption model. Design/Methodology/Approach - In this paper, we theoretically explore the relationship of the antecedents of perceived value(credibility, expertise, attractiveness, economic feasibility, security, and interactivity) and its outcomes (perceived usefulness, perceived risk and perceived value). The outcomes of this research is a conceptualization of antecedents of perceived value supported by research hypothesis based on the existing literature. A total of 100 valid questionnaires were collected to empirically test the research model. Findings - The analysis results showed that credibility, economic feasibility, and interactivity positively influenced perceived usefulness. On the other hand, credibility, professionalism and interactivity negatively influenced perceived risk. Perceived usefulness positively affects perceived value and perceived risk has a negative effect on perceived value. The brand image as a moderating variable was found to decrease the effect of perceived risk on perceived value. Research Implications - The contribution of this study is significant for video conferencing providers as follows. First, a service provider can actively utilize influencers or referees with high credibility and expertise to maximize the perceived usefulness of users. Second, economic feasibility should be ensured in respect of users through various alliance discount strategies. Third, a video conferencing service company needs to build a positive brand image in order to increase users' perceived value.

• Geomechanics and Engineering
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• 제31권5호
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• pp.439-452
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• 2022

A forecast of slope behavior during catastrophic events, such as earthquakes is crucial to recognize the risk of slope failure. This paper endeavors to eliminate the significant supposition of predefined slip surfaces in the slope stability analysis, which questions the relevance of simple conventional methods under seismic conditions. To overcome such limitations, a methodology dependent on the slip line hypothesis, which permits an automatic generation of slip surfaces, is embraced to trace the extreme slope face under static and seismic conditions. The effect of earthquakes is considered using the pseudo-static approach. The current outcomes developed from a parametric study endorse a non-linear slope surface as the extreme profile, which is in accordance with the geomorphological aspect of slopes. The proposed methodology is compared with the finite element limit analysis to ensure credibility. Through the design charts obtained from the current investigation, the stability of slopes can be assessed under seismic conditions. It can be observed that the extreme slope profile demands a flat configuration to endure the condition of the limiting equilibrium at a higher level of seismicity. However, a concurrent enhancement in the shear strength of the slope medium suppresses this tendency by offering greater resistance to the seismic inertial forces induced in the medium. Unlike the traditional linear slopes, the extreme slope profiles mostly exhibit a steeper layout over a significant part of the slope height, thus ensuring a more optimized solution to the slope stability problem. Further, the susceptibility of the Longnan slope failure in the Huining-Wudu seismic belt is predicted using the current plasticity approach, which is found to be in close agreement with a case study reported in the literature. Finally, the concept of equivalent single or multi-tiered planar slopes is explored through an example problem, which exhibits the appropriateness of the proposed non-linear slope geometry under actual field conditions.

• 한국산업정보학회논문지
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• 제15권2호
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• pp.127-137
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• 2010

Widget은 Web 2.0 및 모바일 컨버젼스 패러다임을 주도하는 차세대 지능형 플랫폼으로 평가 받고 있다. 향후 이러한 widget의 발전을 예상할 때, 현재 사용자들의 인식에 대한 분석은 앞으로 widget의 방향성을 결정하는데 무엇보다 필요할 것이다. 따라서 본 연구의 목적은 widget의 사용에 영향을 주는 인터페이스 요인을 규명하여 인터페이스 요인에 따른 widget의 사용의도를 설명함으로써 widget 활성화를 위한 전략적 방안을 모색하는 것이다. 분석 결과 일관성, 직관성, 최소한의 조작, 개인화가 인지된 용이성에 정의 영향을 주며, 개인화와 시각적 매력은 인지된 즐거움에 영향을 줌을 확인하였다. 또한 인지된 용이성은 인지된 즐거움에 영향을 주며, 인지된 즐거움은 사용의도에 직접적인 영향을 주었다. 그러나 인지된 용이성이 사용의도에 직접적인 영향을 준다는 가설은 기각되었다.

• Journal of Korea Trade
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• 제27권3호
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• pp.65-86
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• 2023

Purpose - As globalization progresses, complexity also increases, and various factors that threaten port functions are emerging. Accordingly, the demand for port security to prevent the crisis and resilience that quickly recovers its original function after the crisis is also increasing in port operations. However, few studies have examined how to ensure the port security and how the resilience affects operation performance of port and sustainability performance as well. So the study aims to find out how port security affects port resilience and port operational performance, and consequently, this two factors affect socioeconomic and environmental sustainability performance respectively and synthetically. Design/methodology - Confirmatory Factor Analysis (CFA) was first performed to determine the validity of the factors of model and hypothesis test was performed using Structural Equation Model (SEM) to analyze the Port Performance Model, which show the perception logic among port security level, port resilience, operation performance, and sustainability performance. In order to empirically analyze this model, total 264 respondents from port security operators, shipping companies in South Korea were surveyed. Findings - As result of SEM, First, port security level positively affected the resilience (H1) and cargo operational performance (H2) but not in both of the sustainability performances (H3, H4). Second, resilience positively affected only cargo operational performance (H5) and socio-economic sustainability performance (H7). Last, cargo operation performance positively affects the both of sustainability performances (H8, H9). Originality/value - It was confirmed that port security could improve cargo operational performance through ensuring port resilience and eventually increase the socio-economic sustainability. Therefore the study implies that careful integration and management of port security, port resilience, and sustainability are required, along with compromise on sustainable development goals in the social, economic, and environmental area among all stakeholders.

• Journal of Korea Trade
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• 제27권4호
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• pp.1-18
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• 2023

Purpose - The purpose of this paper is to study how flexibility and mutuality in determining trade terms impact logistics efficiency in the context of relational theory. Additionally, the effect of relational contracts on logistical efficiency relative to the value of the goods being traded is investigated. Design/methodology - According to the relational contract theory, we developed 17 factors utilizing a 7-point Likert scale to measure variables related to flexibility, mutuality, logistics efficiency, and the added value of goods. The survey occurred over four months, and was distributed directly, and via email, phone, and online Google surveys. A total of 403 surveys were collected out of 1,800 distributed, and 380 were analyzed. The principal respondents were import/export companies and members of the Korea International Trade Association and the Korea Small and Medium Business Export-Import Association. The collected data were analyzed using frequency analysis, exploratory factor analysis, and correlation analysis using SPSS ver. 26.0 statistical software, and hypothesis test results were derived using Process Macro ver. 3.5. Findings - This study provides evidence that negotiation flexibility for trade terms affects the efficiency of the logistics process, and the mutuality of such arrangements is shown to be associated with the flexibility and efficiency of logistics processes. Additionally, it has been established that companies whose trade goods possess a low degree of added value may experience increased efficiency in logistics operations if they agree to trade terms that are both flexible and mutually beneficial with their counterparts. Originality/value - This study suggests that in an environment of rapidly shifting global logistics and unpredictable related costs, trade companies may be able to improve logistics efficiency by establishing flexible, mutually beneficial trade terms when entering into contracts. Furthermore, it is suggested that companies dealing in low-value-added products may improve the logistical performance of approaching trade from a perspective of relational contracts.

• 유통과학연구
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• 제21권5호
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• pp.11-18
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• 2023

Purpose: The purpose of this article is to determine whether there are differences in the level of return and risk of the conventional and Islamic capital markets. Research design, data and methodology: This study takes data on the Jakarta Islamic Index (JII) and the Liquid-45 (LQ45) stock groups in the 2017 to 2020 period. The research approach used is quantitative research with a type of comparison. The data used secondary data sourced from the closing price of shares on the Indonesia Stock Exchange. The statistical method used to test the hypothesis is a different test or independent sample t-test. Results: There is a significant difference between the rate of return and investment risk in JII and LQ-45. The rate of return and risk of investing in LQ-45 is higher than that of JII. Conclusions: There is a significant difference in the rate of return on investment in Jakarta Islamic Index (JII) and LQ-45, including conventional stock Liquid-45 (LQ-45) is higher than the rate of return on shares of JII shares. There is a significant difference in the level of investment risk in the Jakarta Islamic Index (JII) and the Liquid-45 (LQ-45), where the risk level for the LQ-45 is higher than that of the JII shares.

• 임상간호연구
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• 제15권1호
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• pp.67-77
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• 2009

Purpose: This study was aimed to investigate the effects of Lebed method exercise (LME) on nurses' depression, anxiety and stress. The LME is a therapeutic exercise and movement program developed by Sherry Lebed Davis and expected to lessen the stress level of nurses and enhance the nursing job's satisfaction and efficiency. This study was utilized a non equivalent control group pre-post test design. Method: The subjects were 36 nurses in total; 18 in experimental group and 18 in control group. The data were collected from March to August, 2008. For the experimental group, 8 hour-long lectures on stress management and LME were given for 12 weeks. For the control group, only lectures on stress management was given. Depression, anxiety, perceived stress, and heart rate variability were measured on the subjects in both groups as pre- and post tests. The data were analyzed by Kolmogrov-Smirov test and P-P plot, t-test and $x^2-test$ using the SPSS program. Results: As proposed in the hypothesis, the subjects in the experimental group experienced less depression (t=2.286, p=.029), less anxiety (t=3.319, p=.002) and less perceived stress(t=2.862, p=.007) than those in the control group. Conclusion: The LME is considered an effective exercise to improve depression, anxiety, and to lessen stress for the nurses. The LME program has potential to be one of the effective stress management interventions for nurses in the future.

• 동아시아경상학회지
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• 제10권1호
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• pp.35-45
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• 2022

Purpose - In spite of the growing importance of Taiwanese green industry, most of employees who work in this industry in Taiwan are dominated by males. Only a few females are working in this industry and their wage is lower. This research is applying role congruity theory which explains why females share only a small portion in Taiwan's green industry. This study addresses a research question, "How has the gender inequality and discrimination been reflected in the occupation structure of Taiwan's green industry? How has this gender occupation structure influenced females in the green industry?" Research design, data, and methodology - To find out the impact of gender role in the green industry, the dataset of the 2015 Taiwan Social Change Survey is used. Using STATA, t test has been implemented to address our research question with three hypotheses. Result -All of hypothesis were all supported. It is found there is a statistical difference in stereotypical thinking between female who work in the green industry and the non-green industry of Taiwan. The limited female representation in the green industry of Taiwan influences job matching and job satisfaction significantly. Conclusion - This study suggests the Taiwanese government should encourage STEM education for females and provide more relevant vocational education and training particularly for females' competency development in the green industry. By providing vocational education and training to meet the skill needs of greener economy resilient to climate change, Taiwan's green industry will grow further and will overcome gender inequality and discrimination.

• 유통과학연구
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• 제20권1호
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• pp.1-11
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• 2022

Purpose: Increasing advancements in the technology industry are forcing people to become more accustomed to digital financial transaction activities. The need for fast and secure payment mechanisms has birthing new idea to digital financial transaction services. Along with increasing access to technology in digital payments, new service is developed in the form of digital wallets as the successor for electronic money. Research design, data and methodology: This research aims to find out whether using QR code as digital payment tool can build customer loyalty in consumers, especially to measure the factors of satisfaction, trust and commitment of customers to do payments with QR Codes. The QR code in this study is refer to the Quick Response Code Indonesian Standard (QRIS) which was officially implemented by Bank Indonesia starting on January 1, 2020 as a means of payment for digital transactions nationally. The research method uses a quantitative approach by way of surveying questionnaires using Likert scale of 100 samples. Results: The hypothesis analysis proved that the variables of satisfaction, trust and commitment together have positive and significant influences on customer loyalty. Conclusion: This research found that there are high interest in Millennials to do transaction using QRIS because it is deemed to be more easy, quick and safe. If a customer achieves a level of loyalty in the usage of digital transaction using QRIS then cashless society lifestyle can be considered successful and can be used in the future.