• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.287.1-287.1
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• 2016

Three-dimensional (3-D) semiconductor nanoarchitectures, including nano- and micro- rods, pyramids, and disks, are emerging as one of the most promising elements for future optoelectronic devices. Since these 3-D semiconductor nanoarchitectures have many interesting unconventional properties, including the use of large light-emitting surface area and semipolar/nonpolar nano- or micro-facets, numerous studies reported on novel device applications of these 3-D nanoarchitectures. In particular, 3-D nanoarchitecture devices can have noticeably different current spreading characteristics compared with conventional thin film devices, due to their elaborate 3-D geometry. Utilizing this feature in a highly controlled manner, color-tunable light-emitting diodes (LEDs) were demonstrated by controlling the spatial distribution of current density over the multifaceted GaN LEDs. Meanwhile, for the fabrication of high brightness, single color emitting LEDs or laser diodes, uniform and high density of electrical current must be injected into the entire active layers of the nanoarchitecture devices. Here, we report on a new device structure to inject uniform and high density of electrical current through the 3-D semiconductor nanoarchitecture LEDs using metal core inside microtube LEDs. In this work, we report the fabrications and characteristics of metal-cored coaxial $GaN/In_xGa_{1-x}N$ microtube LEDs. For the fabrication of metal-cored microtube LEDs, $GaN/In_xGa_{1-x}N/ZnO$ coaxial microtube LED arrays grown on an n-GaN/c-Al2O3 substrate were lifted-off from the substrate by wet chemical etching of sacrificial ZnO microtubes and $SiO_2$ layer. The chemically lifted-off layer of LEDs were then stamped upside down on another supporting substrates. Subsequently, Ti/Au and indium tin oxide were deposited on the inner shells of microtubes, forming n-type electrodes of the metal-cored LEDs. The device characteristics were investigated measuring electroluminescence and current-voltage characteristic curves and analyzed by computational modeling of current spreading characteristics.

• Ocean Systems Engineering
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• v.6 no.1
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• pp.61-97
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• 2016

This is the second of two papers on the 3D numerical modeling of nearshore hydro- and morphodynamics. In Part I, the focus was on surf and swash zone hydrodynamics in the cross-shore and longshore directions. Here, we consider nearshore processes with an emphasis on the effects of oceanic forcing and beach characteristics on sediment transport in the cross- and longshore directions, as well as on foreshore bathymetry changes. The Delft3D and XBeach models were used with four turbulence closures (viz., ${\kappa}-{\varepsilon}$, ${\kappa}-L$, ATM and H-LES) to solve the 3D Navier-Stokes equations for incompressible flow as well as the beach morphology. The sediment transport module simulates both bed load and suspended load transport of non-cohesive sediments. Twenty sets of numerical experiments combining nine control parameters under a range of bed characteristics and incident wave and tidal conditions were simulated. For each case, the general morphological response in shore-normal and shore-parallel directions was presented. Numerical results showed that the ${\kappa}-{\varepsilon}$ and H-LES closure models yield similar results that are in better agreement with existing morphodynamic observations than the results of the other turbulence models. The simulations showed that wave forcing drives a sediment circulation pattern that results in bar and berm formation. However, together with wave forcing, tides modulate the predicted nearshore sediment dynamics. The combination of tides and wave action has a notable effect on longshore suspended sediment transport fluxes, relative to wave action alone. The model's ability to predict sediment transport under propagation of obliquely incident wave conditions underscores its potential for understanding the evolution of beach morphology at field scale. For example, the results of the model confirmed that the wave characteristics have a considerable effect on the cumulative erosion/deposition, cross-shore distribution of longshore sediment transport and transport rate across and along the beach face. In addition, for the same type of oceanic forcing, the beach morphology exhibits different erosive characteristics depending on grain size (e.g., foreshore profile evolution is erosive or accretive on fine or coarse sand beaches, respectively). Decreasing wave height increases the proportion of onshore to offshore fluxes, almost reaching a neutral net balance. The sediment movement increases with wave height, which is the dominant factor controlling the beach face shape.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.2
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• pp.49-62
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• 2016

Technology-based start-ups have great economic ripple effect such as economic growth and job creation. Therefore, a strategic approach is required in order for such start-ups to continuously grow. However, many technology-based start-ups do not survive the Death-Valley and are being eliminated from the market. This is an empirical study on influencing variables that have impact on their performance. This study presents growth intention and influencing variables that have impact on performance (financial performance, technological performance) based on previous research on technology-based start-up. Also, this study examines the relationship between entrepreneurial competence, team commitment and growth intention, and finds the effect of controlling business-network. Structural equation modeling was performed in order to test the research hypothesis. Survey was conducted on the firms that have been certified by Youth Startup Academy of Small and Medium Business Corporation. A total of 306 samples were collected from the survey. An empirical test was conducted on the research hypothesis using SPSS 21.0 and Amos 22.0. The result of hypothesis test shows that growth intention has positive influence on both financial and technological performance, and entrepreneurial competence (technological competence, strategic management competence, creative competence and team commitment) has positive influence on growth intention. Also, the research proved that business-network has regulation effect between human resource trait and growth intention. The result of our study will provide practical insight to future start-ups for continuous growth and successful running of their firm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.1C
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• pp.21-35
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• 2002

Nowadays, in accordance with increasing expectations of multimedia stream service on the internet, a lot of distributed applications are being required and developed. But the models of the existing systems have the problems that cannot support the extensibility and the reusability, when the QoS relating functions are being developed as an integrated modules which are suited on the centralized controlled specific-purpose application services. To cope with these problems, it is suggested in this paper to a distributed QoS management system on CORBA, an object-oriented middleware compliance. This systems we suggested can provides not only for efficient control of resources, various service QoS, and QoS control functions as the existing functions, but also QoS control real-time negotiation and dynamic adaptation in addition. This system consists of QoS Control Management Module(QoS CMM) in client side and QoS Management Module(QoS MM) in server side, respectively. These distributed modules are interfacing with each other via CORBA on different systems for distributed QoS management while serving distributed streaming applications. In phase of design of our system, we use UML(Unified Modeling Language) for designing each component in modules, their method calls and various detailed functions for controlling QoS of stream services. For implementation of our system, we used OrbixWeb 3.1c following CORBA specification on Solaris 2.5/2.7, Java language, Java Media Framework API 2.0 beta2, Mini-SQL 1.0.16 and the multimedia equipments, such as SunVideoPlus/Sun Video capture board and Sun Camera. Finally, we showed a numerical data controlled by real-time negotiation and adaptation procedures based on QoS map information to GUIs on client and server dynamically, while our distributed QoS management system is executing a given streaming service.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.6
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• pp.727-737
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• 1999

프로세스 중심 소프트웨어 개발 환경(PSEE : Process-centered Software Engineering Environment)은 소프트웨어 개발자를 위한 여러가지 정보의 제공과 타스크의 수행, 소프트웨어 개발 도구의 수행 및 제어, 필수적인 규칙이나 업무의 수행등과 같은 다양한 행위를 제공하는 프로세스 모형의 수행을 통하여 소프트웨어 개발 행위를 지원한다. SEED(Software Engineering Environment for Development)는 효율적인 소프트웨어 개발과 프로세스 모형의 수행을 제어하기 위해 ETRI에서 개발된 PSEE이다.본 논문에서는 SEED에서 프로세스 모형을 설계하기 위해 사용되는 SimFlex 프로세스 프로그래밍 언어와, 수행지원시스템인 SEED Engine의 구현에 대하여 기술한다. SimFlex는 간단한 언어 구조를 가진 프로세스 프로그래밍 언어이며, 적절한 적합화를 통하여 다른 PSEE에서 사용될 수 있다. SimFlex 컴파일러는 SimFlex에 의해 기술된 프로세스 모형을 분석하고, 모형의 오류를 검사하며, SEED Engine에 의해 참조되는 중간 프로세스 모형을 생성한다. 중간 프로세스 모형을 사용하여 SEED Engine은 외부 모니터링 도구와 연관하여 사용자를 위한 유용한 정보뿐만 아니라 SimFlex에 의해 기술된 프로세스 모형의 자동적인 수행을 제공한다. SimFlex 언어와 수행지원 시스템의 지원을 통하여 소프트웨어 프로세스를 모형화하는데 드는 비용과 시간을 줄일 수 있으며, 편리하게 프로젝트를 관리하여 양질의 소프트웨어 생산물을 도출할 수 있다. Abstract Process-centered Software Engineering Environments(PSEEs) support software development activities through the enaction of process models, providing a variety of activities such as supply of various information for software developers, automation of routine tasks, invocation and control of software development tools, and enforcement of mandatory rules and practices. The SEED(Software Engineering Environment for Development) system is a PSEE which was developed for effective software process development and controlling the enactment of process models by ETRI.In this paper, we describe the implementation of the SimFlex process programming language used to design process models in SEED, and its runtime support system called by SEED Engine. SimFlex is a software process programming language to describe process models with simple language constructs, and it could be embedded into other PSEEs through appropriate customization. The SimFlex compiler analyzes process models described by SimFlex, check errors in the models, and produce intermediate process models referenced by the SEED Engine. Using the intermediate process models, the SEED Engine provides automatic enactment of the process models described by SimFlex as well as useful information for agents linked to the external monitoring tool. With the help of the SimFlex language and its runtime support system, we can reduce cost and time in modeling software processes and perform convenient project management, producing well-qualified software products.

• 한국노년학
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• v.34 no.2
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• pp.387-407
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• 2014

This study aims to identify the multiple trajectories of depressive symptoms and the characteristics of each trajectory group among the elderly. This study uses five waves of longitudinal data from the Korean Welfare Panel Study (KWPS, 2006-2010). Subjects were older adults aged 60 and over who had completed at least three waves between 2006 and 2010. A total of 4,181 respondents were analyzed. The latent growth mixture model and the multiple logistic regression model were mainly used for data analysis. The major findings were as follows: After controlling for the variables of gender, age, education, marital status, self-assessed health, and poverty, this study identified four different trajectory classes: stable low depressive symptoms (71.8%), high but decreased depressive symptoms (10.6%), moderate but increased depressive symptoms (7.9%), and an increased, then a decreased pattern of depressive symptoms (9.7%). The characteristics of theses trajectories as compared to previous studies were a lower percentage of 'stable low depressive symptoms', no 'persistently high depressive symptoms', and higher level of depressive symptoms. Also, the elderly in the stable low trajectory group had better health status, higher self-esteem and a good relationship with family members, having longer working periods, and more living in non-poverty. In addition, chronic health problems, loss of spouse, and household income differentiated the increased and then decreased pattern from the low stable pattern. Also, age and public pension differentiated the moderated but increased pattern from the low stable pattern. Based on the findings of this study, the researchers suggested political and practical implications for reducing depressive symptoms in later life.

• Journal of the Korean earth science society
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• v.29 no.2
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• pp.163-174
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• 2008

In this study, we compared textbook knowledge organization with students' mental models to contribute to a more well-designed instruction scheme. The selected science content was the cause of moon phases. We investigated 9 textbooks and 25 third-year middle school students. Patterns and features in participants' mental models were identified through cross inter-rater data analysis by 9 researchers, including in service teachers and experts in science education. According to the results, observing and modeling are the main activities engaged in when dealing with moon phases. The activities consisted of such concepts as: lunar revolution, the sun's parallel rays, the illuminated half of moon, and the relative positions of the sun, moon, and earth. Each concept involved inquiry skills such as: creating and manipulating models, utilizing the relationship between time and space, and communicating. However, the most important skills which are required for authentic scientific inquiry, namely controlling variables and formulating hypotheses, were missing. We categorized students' mental models into three types: scientific models, mixed models, and alternative models. The knowledge structure of each of the models was also discussed in this paper. Consequently, it was found that, typically, students were not given enough opportunities to strengthen the connection among ideas.

• Journal of the Korean Geotechnical Society
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• v.29 no.4
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• pp.23-32
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• 2013

In order to evaluate the bearing capacity behaviour of a monopod suction bucket foundation for an offshore wind tower at the western sea of Korea, a centrifuge load test and numerical analyses were performed. The monopod bucket foundation was designed to be installed in a silty sand layer. The model soil was prepared to simulate a target site by using soil samples having similar properties and controlling relative density. In-flight miniature cone penetration test and bender element array were used to confirm that the model soil had represented the target site conditions. The load - rotation curve of the centrifuge load test was analysed. A series of numerical analyses were performed to validate the experimental conditions. Self-weight of the model, distance to the boundary and elastic modulus of the soil layer were varied to study their effects on the load - rotation curves.

• Journal of the Korea Society of Computer and Information
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• v.16 no.12
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• pp.1-10
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• 2011

As requirements of embedded system get complicated, the tool for analyzing the reliability of embedded software is being needed. A probabilistic modeling is used as the way of analyzing the reliability of a software and to apply it to embedded software controlling multiple devices. So, it is necessary to specialize that to embedded software. Also, existing reliability analyzers should measure the transition probability of each condition in different ways and doesn't consider reusing the model once used. In this paper, we suggest a reliability analyzer for embedded software using embedded software Markov chin model and a unit testing tool. Embedded software Markov chain model is model specializing Markov chain model which is used for analyzing reliability to an embedded software. And a unit testing tool has host-target structure which is appropriate to development environment of embedded software. This tool can analyze the reliability more easily than existing tool by automatically measuring the transition probability between units for analyzing reliability from the result of unit testing. It can also directly apply the test result updated by unit testing tool by representing software model as a XML oriented document and has the advantage that many developers can access easily using the web oriented interface and SVN store. In this paper, we show reliability analyzing of a example by so doing show usefulness of reliability analyzer.

• 한국사회정책
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• v.20 no.3
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• pp.141-170
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• 2013

The purpose of this study is to find out the relationship among the degree to provide emotional labor, personal relationship and the intent to stay of female care service workers. Specifically, this study focuses on the mediating effect of the personal relationship (client and agency relation). The path analysis and structural equation modeling analysis were performed on the collected data using SPSS18.0. and AMOS 8.0. And Sobel test conducted for examine the mediating effect. The results are the followings. First, the result of the analysis showed that agency relationship was an indirect factor as the partial mediating effect on relationship between the degree to provide emotional labor and the intent to stay for the care women workers. The result suggests that education utilizing various techniques and strategies to overcome the difficulty accompanied by emotional labor such as communication education and the government try to effort managing and controlling the agency which impact on the labor condition of care workers. Second, the government also tries to provide the trust and collaboration network system which construct a good relationship between the care worker and the agency.