• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.1
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• pp.63-74
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• 2001

In this study, a cycle simulation program of a Unit-Injection(UI) system was developed to estimate the injection performance of newly designed injection system. A fundamental theory of the simulation program is based on the conservation law of mass. Loss of fuel mass in the system due to leakage, compressibility effect of the liquid fuel and friction loss in the control volume was considered in the algorithm f the program. For the evaluation of the simulation program developed, the experimental result which was offered by the Technical Research Center of Doowon Precision Industry Co. was incorporated. Two main parameters; the maximum pressure in the plunger chamber and total fuel mass(kg) injected into the engine cylinder per cycle, were measured and compared with the simulation results. It was found that the maximum error rate of the simulation result to the experimental output was less than 3% in the rated rotational speed (rpm) range of the plunger cam.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.36-40
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• 2003

On analyzing the power circuit of a DVR system, control limitations and control targets are presented for the voltage compensation in DVRs. The control delay in digital controllers increases the dimension of the system transfer function one degree higher which makes the control system more complicate and more unstable. Based on the power stage analysis, a novel controller for the compensation voltages in DVRs is proposed by a feedforward control scheme. Proposed controller works well with the time delay in the digital control system. This paper also proposes a guide line to design the control gain, appropriate output filter parameters and inverter switching frequency for DVRs in digital controllers. Proposed theory is verified by an experimental DVR system with a typical digital controller.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.363-366
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• 2008

It was accomplished that failure analysis not only failure numbers but also power system components every years. and these informations help power system operation considerably. power system equipment were occurred a break down by natural phenomenon and aging but it was not able to predict this failure number. But many papers and technical repots study for each equipment failure rate and reliability evaluation methods. so this paper show a failure number prediction whole power system component using Markov theory not each component failure probability. the result present a next month system failure number prediction.

• Management & Information Systems Review
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• v.9
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• pp.1-23
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• 2002

The Information System is now becoming a very important part of our livers. It encompasses technical and spactial characteristics that are much more different from the order information systems used up until now. Therefore, as various fields within the Information Center are researched, the proper usage of those fields must be well thought-out. This study presents the application of quality management systems in Library, Korea. The purpose of this study is to build a framework of improving the management system and planning and performing the service of high quality in Library. To achieve this goal, a theoretical approach was tried through the previous study and the performed with the subject of the 4 steps by Damming' quality management theory. This study may enable domestic organizations to draw up a concrete and practical plan in Library.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2004.11a
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• pp.295-300
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• 2004

Growing concern and technical improvement in the housing industry has promoted continuous customization to be the most significant parameter for ecological and social sustainability of housing. The basic principle of Open Building is based on the concept of sustainability, but the theoretical relationship of the open housing system in terms of environmental architecture has not been examined profoundly yet. In order to generate an overall approach toward sustainable housing, a further alignment between Open Building and sustainability should be established. Therefore, this study aims at the establishment of the theoretical relationship between Open Housing system and environmental architecture, and the examination of Open Housing system in terms of sustainability for the suggestion of the future development in housing environment.

• Journal of Korean Library and Information Science Society
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• v.10
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• pp.95-131
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• 1983

Index is a systematic guide to items contained in, or concepts derived from, a collection, Thus, it is represented as a paired set of index terms (t) and documents (D) : I= {(t,D) vertical bar t .mem. V, D .mem. W), where V is index vocabulary and W is document collection. Indexing is the process of analysing the informational content of records of knowledge and expressing the informational content in the language of the indexing system. It involves: 1) Selecting indexable concepts in a document; and 2) expressing these concepts in the language of the indexing system (as index entries): and an ordered list. Indexing process involves technical, semantic and syntactic problems. Technical problems are related to the accuracy of indexing, which is primarily governed by the indexer's ability of analysing subject, identifying indexable concepts, and coding. The proper levels of indexing exhaustivity, and index language specificity are also significant factors affecting the quality of index. Semantic problems are related to the choice of index terms and the form in which they should be used. Equivalent, hierarchical and affinitive/associative relationships of index terms are involved. Syntactic problems are largely related to the coordination of index terms. This process of coordination arises from the need to be able to search for the intersection of two or more classes defined by terms denoting distinct concepts. Finally, most valuable aspects of alphabetical subject indexing theories and practices are derived from those of Cutter, Kaiser, Ranganathan, Coates, Lynch and Austin, and discussed in details.

• Structural Engineering and Mechanics
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• v.54 no.1
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• pp.69-85
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• 2015

In this paper, a receding contact problem for an elastic layer resting on two quarter planes is considered. The layer is pressed by a stamp and distributed loads. It is assumed that the contact surfaces are frictionless and only compressive traction can be transmitted through the contact surfaces. In addition the effect of body forces are neglected. Firstly, the problem is solved analytically based on theory of elasticity. In this solution, the problem is reduced into a system of singular integral equations in which contact areas and contact stresses are unknowns using boundary conditions and integral transform techniques. This system is solved numerically using Gauss-Jacobi integral formulation. Secondly, two dimensional finite element analysis of the problem is carried out using ANSYS. The dimensionless quantities for the contact areas and the contact pressures are calculated under various distributed load conditions using both solutions. It is concluded that the position and the magnitude of the distributed load have an important role on the contact area and contact pressure distribution between layer and quarter plane contact surface. The analytic results are verified by comparison with finite element results.

• Lingua Humanitatis
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• v.7
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• pp.57-92
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• 2005

The main driving force behind Chomskyan theory of language that is gaining ground under the title of the "minimalist program" has been the urge to reduce the variety of natural languages to a minimal number of theoretical concepts and devices and to formulate the strongest possible hypothesis about linguistic structures. This has led to a long series of proposals of ever greater abstractness, with concomitant modifications in a number of theoretical constructs. The minimalist approach is the latest development of these constant changes, for which there is really "only one computational system and one lexicon," the differences among languages being reducible to parametric variation in "nonsubstantive parts of the lexicon"(Chomaky 1995:169-70). Chomsky thus differs, now more than ever, from other linguists by his sweepingly programmatic, rather than empirical, approach to language. The proposals he makes are too complicated to discuss here in any technical details. We rather focus on a series of lectures delivered by an ardent adherent of the minimalist program, with the view to demonstrating how this theory may mislead and distort the whole prospect of linguistic investigation. The rationale of the so-called 'minimalism' per se will be called into question.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.1
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• pp.91-105
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• 2016

The purpose of this study was to examine the awareness of elementary teachers about educational technology. Educational technology that is embodied at school was the form of "systemic structure" whose components are complex and exert close mutual influence on one another, rather than of "systemic assembly" that relationship of components were well controlled. A qualitative epistemological method was used to look into educational technology instead of existing empirical ones. Metaphor analysis was utilized among various qualitative research methods to find out what elementary teachers thought of educational technology. Six elementary teachers were asked to draw a picture to describe what came into their mind when they heard term of "educational technology," and they were interviewed in depth to check what their pictures meant. As a result, elementary teachers expressed their point of views about educational technology as "a scientific, technical and systemized instrument to stir up the learning interest and joy of students," "an action to mechanically fit together every part of education(curriculum)," "educational technology as a teaching and learning method," and "an integrated and overall system." This finding seemed to have something to do with media theory, teaching and learning theory and system theory that have been used in educational technology. This study was expected to be significance in that it investigated the way of looking at educational technology in the field, and confirmed the close relationship between theory and practice, and finally provided an opportunity to reflect on the ontological nature and epistemological method of educational technology.

• Fashion & Textile Research Journal
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• v.25 no.5
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• pp.578-592
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• 2023

This study identified and evaluated by deriving and categorizing concepts related to the user experience of metaverse fashion shows using grounded theory, which is a qualitative research method. Based on experiential marketing theory, in-depth interviews were conducted for 14 days with 14 males and females in their 20s and 30s. The research results and contents are as follows: The causal condition was the purpose of using metaverse fashion shows, and the action/interaction strategy caused by such a case was found to be establishing a system for metaverse fashion shows and promoting a positive brand image. The results included content evaluation of satisfaction, normal, or dissatisfaction. The contextual condition was a change in the form of consumption that emphasized experience, while the interventional condition was psychological distance. Based on this, the core category was defined as "consumption patterns that emphasized the purpose of use and experience affects the metaverse fashion shows and psychological distance appeared as a user experience evaluation through the establishment of a system of metaverse fashion shows and the promotion of a positive brand image". User types were classified as active or passive. Active users have the autonomy to select content according to their individual preferences, and accordingly, their experience preference tends to change. In contrast, passive users' preference for the technical quality of content is relatively low, but they have a high concentration of content diversity and audio-visual interest elements.