• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.8
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• pp.2722-2742
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• 2014

We propose methods of linear transceiver design for two different power constraints, sum relay power constraint and per relay power constraint, which determine signal processing matrices such as base station (BS) transmitter, relay precoders and user receivers to minimize sum mean square error (SMSE) for multi-relay multi-user (MRMU) networks. However, since the formulated problem is non-convex one which is hard to be solved, we suboptimally solve the problems by defining convex subproblems with some fixed variables. We adopt iterative sequential designs of which each iteration stage corresponds to each subproblem. Karush-Kuhn-Tucker (KKT) theorem and SMSE duality are employed as specific methods to solve subproblems. The numerical results verify that the proposed methods provide comparable performance to that of a full relay cooperation bound (FRCB) method while outperforming the simple amplify-and-forward (SAF) and minimum mean square error (MMSE) relaying in terms of not only SMSE, but also the sum rate.

• Advances in Energy Research
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• v.5 no.1
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• pp.31-55
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• 2017

In the present study, PV/T collector was modeled via analysis of governing equations and physics of the problem. Specifications of solar radiation were computed based on geographical characteristics of the location and the corresponding time. Temperature of the collector plate was calculated as a function of time using the energy equations and temperature behavior of the photovoltaic cell was incorporated in the model with the aid of curve fitting. Subsequently, operational range for reaching to maximal efficiency was studied using Genetic Algorithm (GA) technique. Optimization was performed by defining an objective function based on equivalent value of electrical and thermal energies. Optimal values for equipment components were determined. The optimal value of water flow rate was approximately 1 gallon per minute (gpm). The collector angle was around 50 degrees, respectively. By selecting the optimal values of parameters, efficiency of photovoltaic collector was improved about 17% at initial moments of collector operation. Efficiency increase was around 5% at steady condition. It was demonstrated that utilization of photovoltaic collector can improve efficiency of solar energy-based systems.

• Journal of the Korean earth science society
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• v.39 no.4
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• pp.361-377
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• 2018

The purpose of the study was to define five science core competencies introduced in the 2015 revised science curriculum with each component and practical indicators into the frame. Science teachers on site could use it in teaching and developing science program to equip students with the competencies to creatively solve problems which is the aim of science education in the $21^{st}$ century. To develop this frame, we contacted 10 experienced science educators and collected the data through a questionnaire. We coded all responses and categorized into the components and practical indicators of each competency which were all compared with those from well-known theories in order to validate. We then contacted other 35 science educators again to construct the validity to fill out the survey of Likert scale. The finalized science core competency included 19 components in total with practical indicators that can be observable and measurable in the classroom. This frame was used to see how it fits into a STEAM program. The finding was that two different topics of the STEAM program displayed the different description of science core competency usage, which could be used as the prescription of the competency as to whether or not it is more promoted in science class.

• International Journal of Costume and Fashion
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• v.12 no.1
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• pp.83-95
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• 2012

This study aims to develop the 21st century eco design-based fashion products by examining Taller Flora products and presenting eco design approaches. Eco design terms were examined based on literature, and Taller Flora products were explored based on literature and websites. The following research issues were discussed. First, eco design terms are totally handled, thus defining the eco design. Second, eco design-oriented Taller Flora products are examined to explore design approaches. Eco design aims to conserve and heal the global environment with focus on a greater understanding of and interest in nature. As such, eco design is based on a new modern concept of aestheticism that seeks to minimize environmental damage caused by the three processes of production and distribution use and disposal, to take social and moral responsibilities for such activities, and to avoid hurting the environment. Taller Flora brands seek to produce products by keeping close ties with indigenous communities in various nations, and by emphasizing and embracing indigenous people's craftsmanship spirit and creativity Indigenous people use eco-friendly materials and produce products with craftsmanship spirit, and their cooperation by linking different cooperative networks is a good model for strengthening fair trade networks. These addresses the problem of expanding design work through traditional crafting. Therefore, the features of Taller Flora brands presented a new method to approach the eco fashion. The research findings are expected to help develop the eco design of fashion products.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.75-80
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• 2002

The mainly used technique to rectify satellite images with distortion is to develop a mathematical relationship between the pixel coordinates on the image and the corresponding points on the ground. By defining the relationship between two coordinate systems, a polynomial model is designed and various linear transformations are used. These GCP based geometric correction has performed overall plane to plane mapping. In the overall plane mapping, overall structure of a scene is considered, but local variation is discarded. The highly variant height of region is resampled with distortion in the rectified image. To solve this problem this paper proposed the TIN-based rectification on a satellite image. The TIN based rectification is good to correct local distortion, but insufficient to reflect overall structure of one scene. So, this paper shows the experimental result and the analysis of each rectification model. It also describes the relationship GCP distribution and rectification model. We can choose a geometric correction model as the structural characteristic of a satellite image and the acquired GCP distribution.

• The Transactions of the Korea Information Processing Society
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• v.7 no.12
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• pp.3785-3793
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• 2000

Effective synchronization specification model which can specify temrxlral relationship among media resolving asynchronous problem due to variable network delay is necessary in a distributed multimedia system. Therefore in this paper, we propose RTPN(Real- Time Petri Net) synchronization specification model based on Petri Net for multimedia application in a distributed real time environment. The proposed RTPN model supplies a tlexible decsription of the temporal relationship among various media objects by defining primary key media and relative key media according to delay and importance among media. Firing rule is instantly executed by firing function based on QoS values which supports intra-media and inter-media syncbronization. And asynchronous control algorithm for resynchronization of presentation level is possible more effective supporting of QoS.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.01a
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• pp.441-447
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• 2001

The problem of query rewriting using views has interested in the context of data integration where source data is described by the views on global relations. When the query and views are of the form of conjunctive queries, the rewriting is a union of conjunctive queries each of which is contained in the original query and consists of only views. Most previous methods for query rewriting using views are 2-step algorithms. In the first step, they identify the views that are useful in rewriting and in the second step they construct all correct rewritings by combining the views that gained in the first step. The larger the number of selected views in the first step, the larger the number of candidate rewritings in the second step. We want to minimize the number of selected views in the first step by defining stringent conditions for a view to be participated in rewritings. In this paper, first we offer a necessary condition for the existence of a rewriting that includes a view. For the common case that predicate repetitions are not allowed in the bodies of views, we show that our algorithm for testing the condition is done in a polynomial-time. Second, we offer an algorithm to construct contained rewritings using the view instances that are computed in the first step. The exponential containment-mapping test in the second step is not needed in our algorithm.

• Korean Journal of Health Education and Promotion
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• v.15 no.2
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• pp.199-215
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• 1998

The health care environment exerts tremendous influence on community health practices. Here the author mention several major factors that will influence the future plan for health service and health education; that is, economic problem, the issues of decrement of infectious disease, increment of chronic degenerative disease due to natural increase of the elderly, increased frequency of traffic and industrial accidents and the issues of medical-technological advances etc. Therefore, special efforts by health personnel should be made to develop health education and health promotion strategies on a community-wide basis. Accordingly, the flexible accessibility, convenient availability, guaranteed medical service, sufficient supply of health information, and rapidly available medicaid service for special population such as the elderly, the handicapped, the disabled and the poor are considered. Also, the financial support from the central government and local self-government and active participation of health consumer to health service are needed in Korea, The role of the health personnel is to elicit, facilitate and maintain health promoting behavior with his and her assurance for health consumers being competent and supported in the voluntary choice of their health promoting activities. The health promoting activities such as the above mentioned will be produce escalation of their life Quality among Koreans.

• Journal of KIISE:Software and Applications
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• v.31 no.6
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• pp.697-715
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• 2004

Component-Based Development (CBD) is a reuse technology Providing enhancement in productivity through using the unit of component which is larger-grained than an object. However, reference model defining the elements and semantics of CBD component is standardized neither internationally nor in industrial. This yields interoperability and portability problem between CBD platforms, and presents burden of choosing appropriate model to developers. In this paper, we define meta-models for representative component reference models, and identify advantages, disadvantages, and features of each model through technical comparison of meta-models. Besides, through a proposal of essential component model containing common and essential elements that all component models must conform and a extended component model containing maximum elements and mechanisms, we can precisely assess candidate component models in practice.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.4
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• pp.632-638
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• 2002

Extensible 3D(X3D) is a software standard for defining interactive web and broadcast-based 3D content integrated with multimedia. The data size of Web3D representation based on polygon meshes is so large that transferring practical data fast is a hard problem. This paper proposes 3D object structure, a new framework for compact 3D representation with high quality surface shape. By utilizing a free form surface technique, qualified surface are transferred with limited amount of data size and rendered. 3D graphic structure can be regarded ad both polygon meshes and free form surfaces. Therefore, it can be easily integrated to existing Web3D data formats, for example VRML ＆ XML. 3D object structure also enables modeling free form surface shapes intuitively with polygon modeling like operations.