• Computational Structural Engineering
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• v.10 no.2
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• pp.255-263
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• 1997

The optimum design of most structural systems used in practice requires considering design variables as discrete quantities. The present paper shows that the linear approximation method is very effective as a tool for the discrete optimum designs of unsymmetric composite laminates. The formulated design problem is subjected to a multiple in-plane loading condition due to shear and axial forces, bending and twisting moments, which is controlled by maximum strain criterion for each of the plys of a composite laminate. As an initial approach, the process of continuous variable optimization by FDM is required only once in operating discrete optimization. The nonlinear discrete optimization problem that has the discrete and continuous variables is transformed into the mixed integer programming problem by SLDP. In numerical examples, the discrete optimum solutions for the unsymmetric composite laminates consisted of six plys according to rotated stacking sequence were found, and then compared the results with the nonlinear branch and bound method to verify the efficiency of present method.

• Journal of the HCI Society of Korea
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• v.13 no.3
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• pp.35-42
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• 2018

Social Networking Sites (hereafter SNSs) have become a part of people's daily routines. Beginning as a hobby/communicating tool for a specific group of people, SNSs have expanded in terms of the number of users, frequency of access, and depth and range of sharing. It is recently reported that the users experience SNS fatigue from being connected at all time. However, limited research has addressed this issue. The purpose of the present study was to examine the mediating role of reputational concern and expectation of others' responses on the relationship between narcissism and Facebook fatigue. A total of 329 Facebook users completed an online survey. The results showed that individuals who rated high on narcissism experienced a high level of Facebook fatigue, and that both reputational concern and expectation of others' responses partially mediated the relationship between narcissism and fatigue. Implications of the findings and suggestions for future research are discussed.

• Journal of the Korean Society for information Management
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• v.39 no.1
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• pp.45-68
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• 2022

The objective of this study is to investigate the factors which influence biotechnology scientists' data sharing intention. This study employed Ostrom's theory of collective action. The target population of this study includes scientists and students of biotechnology field in South Korea. A total of 411 responses which collected by e-mail were used for the final data analysis. The summary of this study is as follows. First, norm of data sharing and academic reciprocity were found to have significant positive influences on data sharing intention directly. Second, perceived community trust was found to have significant positive influences on data sharing intention when academic reciprocity was the mediator. Third, academic reputation showed the moderating effects on the relationship between norm of data sharing and academic reciprocity, and between norm of data sharing and data sharing intention. These findings show that researchers can approach the data sharing behaviors by using the mechanism of trust, norms, reciprocity, and reputation and indicate necessity for a development of academic reputation system to promote more data sharing behaviors of researchers.

• Journal of Venture Innovation
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• v.7 no.2
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• pp.57-76
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• 2024

A virtual influencer is a digital artifact that primarily operates on social media and acts like the human influencer. This study investigate how the attractiveness and reputation of virtual influencers affect consumers' purchase intentions. Based on previous studies, we developed a research model and questionnaire, and analyzed a total of 371 survey questionnaires using a structural equation model. The study results show that reputation positively affect attachment, imitation desire, and interaction, while attractiveness positively influence attachment and imitation desire but not interaction. Lastly, purchase intention was positively influenced by imitation desire, attachment, and interaction; which indicates that attractiveness, reputation, and interactivity are crucial factors in virtual influencer implementation strategies. The quality and reliability of contents provided by virtual influencers are essential not only for gaining popularity but also for maintaining a good reputation. Additionally, continuous interaction is necessary in order to foster close relationships with consumers. A few practical insights are presented for firms considering to implement a virtual influencer.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.2
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• pp.15-24
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• 2013

Purpose: With the demand of SPECT/CT increasing, the interest in complex diagnostic information of CT is rising along with the expansion of various studies on potential performance value. But the study on reduction of exposure dose generated by CT is not being conducted enough. Therefore, in this study, the goal is to identify how much dose reduction exists when performing the extremity bone SPECT/CT using the flat-panel CT. Materials and Methods: The extremity bone SPECT/CT was performed with two equipments -BrightView XCT (Philips Healthcare, Cleveland, USA) and Brilliance 16 CT (Philips Healthcare, Cleveland, USA)-to identify the exposed dose and image quality resulted by changing scan parameter (mAs) applying for both equipment respectively. The noise value of image and spatial resolution were measured with AAPM CT phantom. Tube voltage (kVp) was fixed to 120 kVp, tube current (mAs) calculated at different mA (20, 30, 40, 50, 60, 70, 80) was applied to both equipments respectively. DLP (dose length product) were calculated at the same distance at respective mAs. Also, we acquired images and % contrast with NEMA IEC body phantom to confirm the effect on image. The output of statistics was analyzed by SPSS ver.18. Results: Regarding AAPM phantom, the noise decreased as the tube current (mAs) increased and flat-panel had less noise than Helical CT. This difference increased at lower dose exposure. As to the evaluation of spatial resolution, we can differentiate the space up to 0.75 mm with both equipments. With scan parameter (mA) growing, the value of DLP increased up to 54-216 mGy cm at flat-panel CT and up to 177-709 mGy cm at Helical CT. Regarding NEMA IEC body phantom, same sphere with varied parameter (mA) shows that similar results. Conclusion: There is no significant differences of image quality in both flat-panel and Helical CT when the scan parameter (mA) is changed respectively. Moreover, we can identify the reduction of exposure dose and confirm %contrast analysis value with maintaining image quality. Therefore, at the extremity bone SPECT/CT requiring high spital resolution without the wide ROI, the flat-panel CT is considered to be more useful and it expected to result in the similar image quality with lower exposure dose compared to Helical CT. Additionally, through this study, we expect to help the reduction of the unnecessary exposure dose.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1169-1170
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• 2015

공기를 주 절연매질로 사용하는 전력기기의 소형화 추세속에서 제품의 절연성능을 확보하기 위해 '절연배리어'인 고체절연물이 사용된다. 고체절연물의 연면 절연성능은 운전 환경에서 발생된 수분 및 오염원 등에 영향을 받기 쉽기 때문에, 다양한 오염도 조건에서 고체절연물의 연면 절연파괴특성 분석이 필요하다. 본 논문에서는 전력기기에 폭넓게 적용되는 있는 고체절연물에 대하여 평등전계가 모의된 평판 - 평판 전극 실험 조건에서 연면거리 및 오염도를 정량화한 전기전도도에 따른 AC 연면 절연파괴특성을 분석하였다. 그 결과, AC 연면 절연파괴전계는 고체절연물 재질에 관계없이 단(短) 갭에서 연면거리에 대한 의존성을 거의 보이지 않았다. 또한, PC 연면 절연파괴전계는 BMC 및 에폭시 대비 높았으며, 이것은 재질에 따른 연면 절연파괴 형태 및 표면의 소수성 차이와 관련이 있는 것으로 사료된다.

• Journal of the Korean association of regional geographers
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• v.16 no.5
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• pp.559-571
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• 2010

This paper aims at, firstly, analyzing the preference of rental apartment owned by real estate companies, and the characteristics of housing location factors which Korean university students prefer, secondly, examining the effect of location factors to housing preferences. Especially, comparative analysis between this study and US students' precedent case study are used, in order to derive the implications about the housing policy. The main results of this study are as follows. Firstly, according to the questionnaire survey results, a great part of Korea and US university students prefer rental apartments owned by real estate companies as next housing after graduation. And a meaningful part of them prefer rental apartments owned by real estate companies as permanent housings. Secondly, according to factor analysis, five new factors such as (1) housing condition, (2) facilities and management, (3) neighborhood, (4) reputation and policy, (5) accessibility are extracted. Finally, according to logistic regression analysis, "facilities and management" and "reputation and policy" factors influence the preference of rental apartment. Therefore, provisions of "facilities and management" and "reputation and policy" factor are important to activate rental apartments owned by real estate companies for young generation.

• Journal of Service Research and Studies
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• v.12 no.2
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• pp.117-134
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• 2022

This study conducted a survey on visitors who visited the 2021-2022 KBL Professional Basketball Stadium in Wonju to understand how professional sports viewing factors affect the club image, club satisfaction, and club reputation. As factors for watching professional sports, four factors were considered: stadium, game situation, spectating cost, and spectator promotion. A total of 450 questionnaires were distributed and 411 questionnaires excluding 39 questionnaires were used as the final analysis data. For the effective questionnaire survey, After analyzing the purpose and purpose of the research, participants were asked to collect data. The collected data were analyzed using SPSS statistical package after data coding and cleaning process. The results of this study are as follows. First, the effect of professional sports viewing factor on brand image was 45.1%, and the factor of pro sports viewing was significant in stadium, competition situation, and promotion of viewing, and had no effect on viewing cost. Second, the influence of professional sporting factor on the satisfaction of the team was 42.5% in explaining power, which was significant in the stadium, the competition situation, the cost of visiting, and promotion of viewing. Third, the influence of professional sports viewing factor on team reputation was 62.1%, and the factor of professional sports viewing was significant in promoting stadium, visiting cost, and viewing, and had no effect on economic situation. The implication of this study is that in order to increase the brand value of the club, it is much more effective to increase the quality of facilities and food and beverages and to activate events for the audience than to lower the cost of viewing.

• Composites Research
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• v.15 no.2
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• pp.11-17
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• 2002

The piezoelectric thin film sensor can be used to interpret variations in structural and material properties, e.g. for structural integrity monitoring and assessment. To illustrate one of this potential benefit, PVDF (polyvinylidene fluoride) film sensors are used for monitoring impact damage in Gr/Ep composite panels. Both PVDF film sensors and strain gages are attached to the surface of Gr/Ep specimens. A series of impact tests at various impact energy by changing impact mass the height are performed on the instrumented drop weight impact tester. The sensor responses are carefully examined to predict the onset of impact damage such as indentation, matrix cracking, and delamination, etc. Test results show that the particular waveforms of sensor signals implying the damage initiation and development are detected above the damage initiation impact energy. As expected, the PVDF film sensor is found to be more sensitive to impact damage initiation event than the strain gage.

• Journal of Food Hygiene and Safety
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• v.28 no.3
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• pp.252-257
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• 2013

In this study the automated technique TEMPO STA method, a new automated enumeration based on MPN method, was compared to the direct plate count method by testing various ready-to-eat compound food products. Artificially inoculated food samples with Staphylococcus aureus - Bibimbap, Bibimnaengmyeon, Mulnaengmyeon, Kimmaki, Salad, Japchae, and Sushi- were tested. Statistical analysis of the results showed above 99% in agreement between the two enumeration methods. Also, we monitored 466 various ready-to-eat compound food products samples. The measure uncertainties of the two methods is also familiar, while TEMPO STA automated method is simpler, less time-consuming, more effective and more stable.