• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.348-351
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• 2006

Bipolar plate, which forms about 50% of the stack cost, is an important core part with polymer electrolyte membrane in PEMFC. Bipolar plates have been commonly fabricated from graphite meterial having high electrical conductivity and corrosion resistance. Lately, many researchers have concentrated their efforts on the development of metallic bipolar plate and stainless steel has been considered as a potential material for metallic bipolar plate because of its high strength, chemical stability, low gas permeability and applicability to mass production. However, it has been reported that its inadequate corrosion behavior under PEMFC environment lead to a deterioration of membrane by dissolved metal ions and an increase in contact resistance by the growth of passive film therefore, its corrosion resistance as well as contact resistance must be improved for bipolar plate application. In this work, several types of coating were applied to 316L and their electrical conductivity and corrosion resistance were evaluated In the simulated PEMFC environment. Application of coating gave rise to low interfacial contact resistances below $19m{\Omega}cm^2$ under the compress force of $150N/cm^2$. It also made the corrosion potential to shift in the posit ive direct ion by 0.3V or above and decreased the corrosion current from ca. $9{\mu}A/cm^2$ to ca. $0.5{\mu}A/cm^2$ in the mixed solution of $0.1N\;N_2SO_4$ and 2ppm HF A coat ing layer under potentiostatic control of 0.6V and $0.75V_{SCE}$ for 500 hours or longer showed some instabilities, however, no significant change in coat Ing layer were observed from Impedance data. In addition, the corrosion current maintained less than $1{\mu}A/cm^2$ for most of time for potentiostatic tests. It indicates that high electrical conductivity and corrosion resistance can be obtained by application of coatings in the present work.

• The Journal of the Korea Contents Association
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• v.16 no.9
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• pp.276-285
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• 2016

In the highly competitive cosmetic industry, each cosmetic brand is striving to increase its profit by providing excellent product quality and delightful marketing campaigns. In this regard, this study investigates consumers' post-purchasing decision-making processes. It considers the two critical post-purchasing behaviors as repurchasing intention and recommendation intention. We posit customer satisfaction and brand image as the key antecedents of post-purchasing behaviors. The effects of cosmetic quality, price fairness, and event activities on consumer satisfaction and brand image are examined. We conducted a questionnaire survey of women in their twenties, which are critical groups in consumer life cycle of cometic products. Data collected from 163 female respondents were empirically tested against a theoretical framework using partial least squares. Analysis results found that both consumer satisfaction and brand image significantly influence post-purchasing behaviors, respectively. Especially, brand image has a stronger effect on post-purchasing behaviors than customer satisfaction does. Cosmetic quality and price fairness play an important role on customer satisfaction and brand image. However, event activities significantly affect consumer satisfaction, while they do not significantly influence brand image.

• The korean journal of orthodontics
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• v.28 no.4 s.69
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• pp.487-498
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• 1998

This study was conducted to investigate changes of airway size, tongue and hyoid position following orthognathic surgery in mandibular prognathism, and how they are adapted to new environment in time dependent manner. 37 patients, who had recieved orthognathic surgery, were selected for this study. lateral cephalogram of each patient was taken at preoperation, immediate postoperation, and over 6 month after operation, and were traced and analyzed The findings of this study were as follows : 1. The size of airway was not changed at PNS and Epiglottis level after operation, but it was changed slightly at 2nd cervical vertebra level. 2. The hyoid was moved inferoposteriorly at immediate postoperation, and then it shifted toward preoperative position, but it remained slightly inferoposterior position. The distance from hyoid to genial tubercle decreased continuously. 3. The position of tongue was moved inferoposteriorly at immediate postoperatioa and then it shifted toward preoperation position, but the root of the tongue remained inferoposteriorly. 4. The distance between tongue and hyoid was increased at immediate postoperation and slightly decreased during follow-up period. 5. The change of the mandibular position was not significantly correlated with changes of airway size, hyoid position, tongue morphology and tongue position.

• Information Systems Review
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• v.18 no.2
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• pp.151-171
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• 2016

With the widespread adoption of mobile devices, such as smart phones and smart pads, as well as the rapid growth of mobile technologies, consumer shopping patterns are changing. This study investigates key factors of consumer purchasing intention in a mobile shopping mall context by incorporating trust belief into the theory of planned behavior. We posit perceived usefulness, perceived enjoyment, perceived ease of use, and trust belief as antecedents of behavioral attitude toward mobile shopping malls. Moreover, social influence and security are identified as key enablers of trust belief on mobile shopping malls. Data collected from 154 consumers with purchasing experience in mobile shopping malls are empirically tested against a research model using partial least squares. Analysis results show that behavioral attitude and perceived behavioral control significantly influence purchasing intention. Moreover, this study reveals the significant effects of perceived usefulness and perceived enjoyment on behavioral attitude. Trust belief indirectly influences purchasing intention through behavioral attitude and is significantly affected by social influence. Understanding consumer purchasing decision-making processes in mobile shopping malls can help service providers to develop effective marketing and operation strategies and campaigns.

• Information Systems Review
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• v.6 no.2
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• pp.79-94
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• 2004

The Internet is now an ubiquitous technology in business and possesses the potential to make the concept of value chain into an attainable reality. We posit that the way the Internet is utilized, the extent of the Internet's impact on business performance, and the extent the firms are prepared to take advantage of the Internet varies from country to country and from industry to industry. Based on data collected from 54 firms in the U.S. and 135 in South Korea, we compared the two countries (U.S. and South Korea) and two major industry groups (manufacturing and service) regarding the pattern of Internet utilization on the Internet from a value chain perspective. The findings show that U.S. companies utilize the Internet more extensively in such areas as human resources management, automation, sales, and advertising than the South Korean counterparts. However, we did not find a statistically significant difference in the way the two countries use the Internet within a value chain model. We also compared Internet practices by industry sector (i.e., service vs. manufacturing) within each country. The results show that firms in the service sector tend to use the Internet more extensively than the manufacturing counterparts in both countries. Particularly in Korea the difference between the sectors was significant in the extent to which they utilized the Internet to support such business activities as inter-organizational alliance, communication, and marketing.

• Management & Information Systems Review
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• v.36 no.3
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• pp.255-268
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• 2017

This study examines whether firms with tax avoidance of Corporate Social Responsibility(CSR) performance is tempered by the extent firms engage in CEO turnovers. Considering the increasing interest in CSR activities of the firm to secure sustainable growth of national economy, this paper investigates the benefit and cost of CSR activities by combining the agency theory using the firm level data. Prior studies document that investors positively value tax avoidance. The rationale for this finding is that tax avoidance provides cash savings that can be used by firm managers to generate future shareholder wealth. Prior studies also show that investors' valuations are sensitive to the risk of future negative tax outcomes. Assuming that many types of CSR performances are low risk, low yielding uses of firm resources, we posit that higher levels of CSR performance may signal to investors that cash generated via tax avoidance has not been fully used to generate a return sufficient to offset the risk associated with aggressive tax planning strategies. Consistent with this argument, we predict and find that the positive association between CSR performance and tax avoidance is significantly weakened when firms have higher positive levels of CEO turnovers. Further, we predict and find that 'philanthropic' types of CSR activities in particular are associated with investor discounting of tax avoidance. We interpret our results as suggesting the equity market views CSR activities to be ostensibly funded through cash savings generated via tax avoidance.

• Interdisciplinary Bio Central
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• v.4 no.3
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• pp.10.1-10.12
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• 2012

Introduction: We investigated frameshift suppressor tRNAs previously reported to use five-base anticodon-codon interactions in order to provide a collection of frameshift suppressor tRNAs to the synthetic biology community and to develop modular frameshift suppressor logic devices for use in synthetic biology applications. Results and Discussion: We adapted eleven previously described frameshift suppressor tRNAs to the BioBrick cloning format, and built three genetic logic circuits to detect frameshift suppression. The three circuits employed three different mechanisms: direct frameshift suppression of reporter gene mutations, frameshift suppression leading to positive feedback via quorum sensing, and enzymatic amplification of frameshift suppression signals. In the course of testing frameshift suppressor logic, we uncovered unexpected behavior in the frameshift suppressor tRNAs. The results led us to posit a four-base binding hypothesis for the frameshift suppressor tRNA interactions with mRNA as an alternative to the published five-base binding model. Conclusion and Prospects: The published five-base anticodon/codon rule explained only 17 of the 58 frameshift suppression experiments we conducted. Our deduced four-base binding rule successfully explained 56 out of our 58 frameshift suppression results. In the process of applying biological knowledge about frameshift suppressor tRNAs to the engineering application of frameshift suppressor logic, we discovered new biological knowledge. This knowledge leads to a redesign of the original engineering application and encourages new ones. Our study reinforces the concept that synthetic biology is often a winding path from science to engineering and back again; scientific investigations spark engineering applications, the implementation of which suggests new scientific investigations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.7
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• pp.3258-3266
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• 2011

This paper empirically explores how resources and family saliency of women entrepreneurs in IT business influence their business performance. Building up on prior research and Shelton[2006], we develop hypothesis on how the strategies of resolving wok family conflict relate to determinants of performance and business performance. The central hypothesis states that role sharing would be the strategy raising up the business performance. We also posit that the role sharing strategy would be adopted by women who show high saliency in both family and work. and women who have high levels of resources. Results suggest that financial resources have significant impact on role sharing strategy and the sales. The hypothesis of positive role sharing effect on the performance is not supported, indicating that combining family role might be an obstacle to business performance of women.

• Phonetics and Speech Sciences
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• v.10 no.4
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• pp.77-89
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• 2018

Speech articulators are coordinated for the purpose of segmental constriction in terms of a task. In particular, vertical jaw movements repeatedly contribute to consonantal as well as vocalic constriction. The current study explores vertical jaw movements in conjunction with bilabial constriction in bilabial stop /p/ in the context /a/-to-/a/. Revisiting kinematic data of /p/ collected using the electromagenetic midsagittal articulometer (EMMA) method from seven (four female and three male) speakers of Seoul Korean, we examined maximum vertical jaw position, its relative timing with respect to the upper and lower lips, and lip aperture minima. The results of those dependent variables are recapitulated in terms of linguistic (different word boundaries) and paralinguistic (different speech rates) factors as follows. Firstly, maximum jaw height was lower in the across-word boundary condition (across-word < within-word), but it did not differ as a function of different speech rates (comfortable = fast). Secondly, more reduction in the lip aperture (LA) gesture occurred in fast rate, while word-boundary effects were absent. Thirdly, jaw raising was still in progress after the lips' positional extrema were achieved in the within-word condition, while the former was completed before the latter in the across-word condition. Lastly, relative temporal lags between the jaw and the lips (UL and LL) were more synchronous in fast rate, compared to comfortable rate. When these results are considered together, it is possible to posit that speakers are not tolerant of lenition to the extent that it is potentially realized as a labial approximant in either word-boundary condition while jaw height still manifested lower jaw position in the across-word boundary condition. Early termination of vertical jaw maxima before vertical lower lip maxima across-word condition may be partly responsible for the spatial reduction of jaw raising movements. This may come about as a consequence of an excessive number of factors (e.g., upper lip height (UH), lower lip height (LH), jaw angle (JA)) for the representation of a vector with two degrees of freedom (x, y) engaged in a gesture-based task (e.g., lip aperture (LA)). In the task-dynamic application toolkit, the jaw angle parameter can be assigned numerical values for greater weight in the across-word boundary condition, which in turn gives rise to lower jaw position. Speech rate-dependent spatial reduction in lip aperture may be able to be resolved by means of manipulating activation time of an active tract variable in the gestural score level.

• Journal of Technology Innovation
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• v.26 no.4
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• pp.29-56
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• 2018

The purpose of this research is to examine whether investment portfolio composition affects the technological performance of corporate venture capital (CVC). The stages of investment are categorized from "start-up/seed", "early", and "expansion", to "later" stage. We posit and test that the investment stage composition in a portfolio is highly correlated with the growth potential and downside risk of the portfolio, which in turn influences an investor's innovation performance. To test this hypothesis, we used negative binomial panel regression with 21 years of deal data from 70 cases of CVC. The results show that there is an inverted U shaped relationship between investment portfolio composition and technological performance. This means that the more seed or early stage investment within the investment portfolio, the higher the innovation performance; however, if the amount of seed or early stage investment is over a certain level, the performance decreases. Further, this study finds that the external partners of a venture negatively moderate the inverted U shaped relationship between portfolio composition and innovation performance. We believe that corporate planners, venture capitalists, and policy makers will be helped by these results showing that companies can maximize their investment performance by considering the investment stage and progress of investments.