• Journal of the Korean Vacuum Society
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• v.18 no.2
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• pp.127-132
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• 2009

We have investigated the intrinsic defects remaining in epitaxial GaSb layers grown on SI-GaAs substrates compared to those in bulk GaSb crystal substrate, which is a basic material of Sb-based strained-layer superlattice infrared photodetectors. From the functional dependence of the band-to-band transition energy of the photomuminescence (PL) spectra observing up to near room-temperature (250 K), the temperature parameters of [$E_o$, $\alpha$, $\beta$] of undoped GaSb crystal are determined by using the Varshni empirical equation describing the temperature variation of the bandgap energy. Additionally to the antisite-Ga ([$Ga_{Sb}$]) with an ionization energy of 29 meV that is well known to a major intrinsic defect in GaSb, epitaxial GaSb layers show a pair of deep states at the emission energy of 732/711 meV that may be related with a complex of two antisite-Ga and antisite-Sb ([$Ga_{Sb}-Sb_{Ga}$]). Based on the analysis of the temperature and the excitation-power dependences of PL, it suggests that excess-Sb substitutes Ga-site by self-diffusion and two anti sites of [$Ga_{Sb}$] and [$Sb_{Ga}$] could form as a complex of [$Ga_{Sb}-Sb_{Ga}$] in GaSb epilayers grown under Sb-rich condition.

• Journal of the Korean association of regional geographers
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• v.15 no.3
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• pp.369-392
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• 2009

Recently international movements of labour as well as those of goods and other production elements such as capitals and technology have been increased rapidly under the process of glocalization. The huge amount of immigrant workers' in-flows makes increasing influences on regional economy in South Korea. This paper examines such impacts of immigrant workers on local labor markets, productivity. and industrial composition and innovation on the basis of analysis of empirical data and review of existing literature on the subject. Despite a problem of simplification, some reasoning can be listed as follows: First of all, the inflow of immigrant workers has an effect of job displacement among domestic simple workers, with duel effects on the status of native workers; secondly, Immigrant workers give a positive effect on local productivity, but only with low level of wage and of purchasing power; thirdly, the in-flow of immigrant workers seems to prevent existing industries from transformation towards new ones and/or from automation and innovation of production facilities, while there seems no clear relationship with foreign direct investments of local firms.

• Journal of Korea Technology Innovation Society
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• v.16 no.4
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• pp.1163-1186
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• 2013

Big science such as nuclear fusion accelerators shares the characteristic of requiring long-term and massive budget input, human power, and related state-of-the-art technology. Because big science, by nature, thus requires large-scale budgets and facilities yet harbors the possibility of failure, most projects are led by the government. When the actual circumstances are examined, however, such projects are often implemented through the formation of cooperative relations with small and medium businesses (SMBs) possessing outstanding technological capacity. On the other hand, the reality is that the entry of corporations into the business ecosystem of big science is not easy and that even those that have once entered big science likewise fail to find sales outlets for technology that they have developed following the supply of single items, thus leading their technological capacity to lie idle. Consequently, based on an awareness of the problem, the present study seeks to propose strategies for activating the business ecosystem of nuclear fusion and accelerators and to present alternatives regarding which policy tasks must be pursued first by using the analytic hierarchy process (AHP) technique. The present study derived the four policy alternatives of approach, care, expansion, and infrastructures in accordance with the results of empirical analysis to activate the business ecosystem of nuclear fusion and accelerators and analyzed their priority in terms of urgency and effectiveness, the results of which were, in this order: care-approach-expansion-infrastructures. The significance of such research results lie in presenting the policy direction when the government determines which policy task must be pursued first and implements strategies for the activation of the business ecosystem of nuclear fusion and accelerators with limited financial resources in the future.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.3
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• pp.23-31
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• 2010

The increasing demands on low-power, and low-complexity video encoder have been motivating extensive research activities on distributed video coding (DVC) in which the encoder compresses frames without utilizing inter-frame statistical correlation. In DVC encoder, contrary to the conventional video encoder, an error control code compresses the video frames by representing the frames in the form of syndrome bits. In the meantime, the DVC decoder generates side information which is modeled as a noisy version of the original video frames, and a decoder of the error-control code corrects the errors in the side information with the syndrome bits. The noisy observation, i.e., the side information can be understood as the output of a virtual channel corresponding to the orignal video frames, and the conditional probability of the virtual channel model is assumed to follow a Laplacian distribution. Thus, performance improvement of DVC systems depends on performances of the error-control code and the optimal reconstruction step in the DVC decoder. In turn, the performances of two constituent blocks are directly related to a better estimation of the parameter of the correlation channel. In this paper, we propose an algorithm to estimate the parameter of the correlation channel and also a low-complexity version of the proposed algorithm. In particular, the proposed algorithm minimizes squared-error of the Laplacian probability distribution and the empirical observations. Finally, we show that the conventional algorithm can be improved by adopting a confidential window. The proposed algorithm results in PSNR gain up to 1.8 dB and 1.1 dB on Mother and Foreman video sequences, respectively.

• KDI Journal of Economic Policy
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• v.27 no.1
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• pp.1-38
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• 2005

Our paper aims to estimate a household consumption function in the presence of liquidity constraints as well as household characteristics. Empirical findings from a Korean cross-sectional data (National Survey of Household Income and Expenditure) reveal that several family characteristics, such as household size, number of working members, children in school, and educational level and age of the household head, turn out to be critical determinants of household consumption. Especially, the influence of household size on consumption decision is shown to be highly significant, not only indirectly through its impact on household income, but also directly by affecting the household's preference for consumption itself. While, the other family characteristics primarily influences household income. Our paper distinguishes itself from existing literature in that it greatly improves the explanatory power of the estimated household consumption function by measuring the degree of the liquidity constraint rather than simply identifying its presence. Based on the assumption that the present value of human capital is a function of household characteristics, the degree of the liquidity constraint is represented by the underestimated portion of the human capital. Such a method of implementing the liquidity constraint is useful in treating various types of assets according to their liquidity. Finally, our estimated household consumption function is applied to decompose cross-sectional variances of consumption inequality. The analysis confirms that the overall alleviation in liquidity constraints in Korea after the 1997 currency crisis reduced consumption inequality despite the worsening of income inequality and changes in the demographic composition of family characteristics during the same period.

• Journal of Distribution Science
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• v.14 no.2
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• pp.93-101
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• 2016

Purpose - This study aims to advance our knowledge about factors influencing technical startup performance through analysing technical startup process empirically. This study was conducted to focus on industry structure(industry growth rate, competitive intensity, and enter barriers), technology characteristics(technical excellence and wide range of technical application), and the performance in the technology-based start-ups. Specifically, analyzing moderating effect of technology-marketing strategy, this studied how moderating variables affect technical startup performance under industry structure. Research design, data, and methodology - The subject of this study was technology-based start-ups company that received technology transfer from public organization. The development of the paper model is based on the literature of the preceding research analysis in technology commercialization, performance of technology-based start-ups, and marketing strategy. This study has a construct that was defined in the previous studies, such that technology marketing strategy was defined into the two ways of being broad or narrow in strategic application. From November 3. 2015 to December 22, 220 questionnaires were distributed with targeting to start-up companies in technology-based. 188 responses were collected for empirical analysis except the missing and wrong value responses. This data were used for structural equation modeling and regression analysis. Results - The results of this study are as follows. First, as industry structure variables influencing on performance(technical, financial) of technology-based start-ups, industry growth rate, competitive intensity and enter barriers of variables were verified; high growth rate has more positive effect on performance than low growth rate, competitive low intensity has more positive effect on performance than competitive high intensity, low enter barriers have more positive effect on performance than high enter barriers. Second, as technology characteristics variables influences on the performance(technical, financial) of technology-based start-ups, technical excellence and wide range of technical application of variables were verified ; technical high-excellence has more positive effect on performance than technology low-excellence, wide range of technical application has more positive effect on performance than narrow range of technical application. We also find that technology marketing strategy(broad/narrow) in moderating factors on performance (technical, financial) is as follows. Analyzing the moderating effect depending on technology marketing strategy(broad/narrow), application of technology, and the types of technology strategy(broad/narrow) were revealed that broad marketing strategy had a more significant effect on performance of technology-based start-ups. With AMOS, the relevancy of the study model revealed higher for broad technology-marketing strategy than narrow technology marketing strategy, and the explanatory power revealed to be 6.4% higher in broad marketing strategy than narrow marketing strategy. Conclusions - This study confirmed that industry structure and technology characteristics are important factors influencing the performance of technology-based start-ups. Technology-marketing strategy affects the performance of technology-based start-ups between industry structure and technology characteristics. According to additional analysis, moderating variables and technology-marketing strategy are important factors influencing the performance of technology-based start-ups under industry structure and technology characteristics. Broad type of technology-marketing strategy has more attractive industry structure and excellent technology characteristics than narrow types of technology-marketing.

• Journal of Distribution Science
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• v.14 no.1
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• pp.93-102
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• 2016

Purpose - The purpose of paper is studying the static and dynamic side for long-term memory storage properties, and increase the explanatory power regarding the long-term memory process by looking at the long-term storage attributes, Korea Composite Stock Price Index. The reason for the use of GPH statistic is to derive the modified statistic Korea's stock market, and to research a process of long-term memory. Research design, data, and methodology - Level shifts were subjected to be an empirical analysis by applying the GPH method. It has been modified by taking into account the daily log return of the Korea Composite Stock Price Index a. The Data, used for the stock market to analyze whether deciding the action by the long-term memory process, yield daily stock price index of the Korea Composite Stock Price Index and the rate of return a log. The studies were proceeded with long-term memory and long-term semiparametric method in deriving the long-term memory estimators. Chapter 2 examines the leading research, and Chapter 3 describes the long-term memory processes and estimation methods. GPH statistics induced modifications of statistics and discussed Whittle statistic. Chapter 4 used Korea Composite Stock Price Index to estimate the long-term memory process parameters. Chapter 6 presents the conclusions and implications. Results - If the price of the time series is generated by the abnormal process, it may be located in long-term memory by a time series. However, test results by price fixed GPH method is not followed by long-term memory process or fractional differential process. In the case of the time-series level shift, the present test method for a long-term memory processes has a considerable amount of bias, and there exists a structural change in the stock distribution market. This structural change has implications in level shift. Stratum level shift assays are not considered as shifted strata. They exist distinctly in the stock secondary market as bias, and are presented in the test statistic of non-long-term memory process. It also generates an error as a long-term memory that could lead to false results. Conclusions - Changes in long-term memory characteristics associated with level shift present the following two suggestions. One, if any impact outside is flowed for a long period of time, we can know that the long-term memory processes have characteristic of the average return gradually. When the investor makes an investment, the same reasoning applies to him in the light of the characteristics of the long-term memory. It is suggested that when investors make decisions on investment, it is necessary to consider the characters of the long-term storage in reference with causing investors to increase the uncertainty and potential. The other one is the thing which must be considered variously according to time-series. The research for price-earnings ratio and investment risk should be composed of the long-term memory characters, and it would have more predictability.

• Culinary science and hospitality research
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• v.19 no.1
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• pp.189-203
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• 2013

The purpose of this study is to examine medicinal food consumption patterns focusing on the consumers living in Gyeongju area, and it attempts to provide database about developing medicinal food products as tourist attractions grounded on the results. For this study, the data was analyzed using SPSS WIN 20.0 for an empirical analysis. Moreover, the survey questions were sent out to 300 people, and total 256 copies of questionnaire were returned for the sample data. For the result that "It will have a significant impact on the selecting attributes of medicinal food according to gender," there was a meaningful difference between gender on the average cost. For the result that "It will have a significant impact on the selecting attributes of medicinal food according to marital status," there was a significant difference between married and single for comparing tastes. For the result that "It will have a significant impact on the selecting attributes of medicinal food according to age," there was a meaningful difference on the degree of awareness, comparing tastes, and comparing health. For the result that "It will have a significant impact on the selecting attributes of medicinal food according to occupation and education," there was a meaningful difference on the degree of awareness. Based on the results of this study, medicinal restaurants should offer various menu items and services to prepare methods to remind consumers of their professionalism in order to enhance competitive power of medicinal food.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.1
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• pp.263-271
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• 2012

The purpose of this study is to investigate the relationship between entrepreneurial factors and entrepreneurial intention on student. This study is designed to examine the effect of entrepreneurial factors on entrepreneurial intention. Data for the study was compiled through surveys on 300 students who study in engineering school of H university. Empirical results of the hypothesis testing are summarized as follows: The results indicate that both two variable groups have positively influenced the entrepreneurial factors was highly related to entrepreneurial intention. The factors entrepreneurship are background, individual and situational factor. This all factors influence on entrepreneurial intention. The entrepreneurial factors had a positively influence on will power of entrepreneur. The entrepreneurial factors had a positively influence on performance of entrepreneur.

• Korea-Australia Rheology Journal
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• v.18 no.2
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• pp.67-81
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• 2006

Using a strain-controlled rheometer, the dynamic viscoelastic properties of aqueous xanthan gum solutions with different concentrations were measured over a wide range of strain amplitudes and then the linear viscoelastic behavior in small amplitude oscillatory shear flow fields was investigated over a broad range of angular frequencies. In this article, both the strain amplitude and concentration dependencies of dynamic viscoelastic behavior were reported at full length from the experimental data obtained from strain-sweep tests. In addition, the linear viscoelastic behavior was explained in detail and the effects of angular frequency and concentration on this behavior were discussed using the well-known power-law type equations. Finally, a fractional derivative model originally developed by Ma and Barbosa-Canovas (1996) was employed to make a quantitative description of a linear viscoelastic behavior and then the applicability of this model was examined with a brief comment on its limitations. Main findings obtained from this study can be summarized as follows: (1) At strain amplitude range larger than 10%, the storage modulus shows a nonlinear strain-thinning behavior, indicating a decrease in storage modulus as an increase in strain amplitude. (2) At strain amplitude range larger than 80%, the loss modulus exhibits an exceptional nonlinear strain-overshoot behavior, indicating that the loss modulus is first increased up to a certain strain amplitude(${\gamma}_0{\approx}150%$) beyond which followed by a decrease in loss modulus with an increase in strain amplitude. (3) At sufficiently large strain amplitude range (${\gamma}_0>200%$), a viscous behavior becomes superior to an elastic behavior. (4) An ability to flow without fracture at large strain amplitudes is one of the most important differences between typical strong gel systems and concentrated xanthan gum solutions. (5) The linear viscoelastic behavior of concentrated xanthan gum solutions is dominated by an elastic nature rather than a viscous nature and a gel-like structure is present in these systems. (6) As the polymer concentration is increased, xanthan gum solutions become more elastic and can be characterized by a slower relaxation mechanism. (7) Concentrated xanthan gum solutions do not form a chemically cross-linked stable (strong) gel but exhibit a weak gel-like behavior. (8) A fractional derivative model may be an attractive means for predicting a linear viscoelastic behavior of concentrated xanthan gum solutions but classified as a semi-empirical relationship because there exists no real physical meaning for the model parameters.