• Transactions of Materials Processing
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• v.16 no.5 s.95
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• pp.401-405
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• 2007

Due to the low densities and high specific strength and stiffness, magnesium alloy sheets are very attractive lightweight materials for automotive and electrical products. However, the magnesium alloy sheets should be usually formed at elevated temperature because of their poor formability at room temperature. For the use of the magnesium alloy sheets for an industrial, their mechanical properties at elevated temperature and appropriate forming process conditions have to be developed. In this study, non-isothermal simulation of a square cup drawing of magnesium alloy sheets have been conducted to evaluate a proper forming process conditions such as the tool temperature, the tool shoulder radius, friction between the blank and the tools. According to this study, appropriate forming process conditions of square cup drawing at elevated temperature from magnesium alloy sheets are suggested.

• Aerospace Engineering and Technology
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• v.2 no.1
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• pp.63-72
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• 2003

On the basis of sensor types, satellites can be classified by two types, which are optical observation satellite and radar observation satellite. A satellite type is selected according to the specific mission. Optical observation satellite is more appropriate for getting high geometric resolution images and radar observation satellite is more appropriate for getting images independent of weather condition the more a demand of satellite increases, the more an importance of information increases. Therefore, development trend and state of earth observation satellite are surveyed and described in this paper. In the future, domestic development of satellites will be planned considering trend of satellite technologies.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.473-476
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• 2003

In this paper, presents a way to maximize transmission efficiency and reception ability through transmission diversity technology, which can be adapted to wireless multimedia OFDM system. The presented method is a comparative analysis between a case where parameter a for time average is 0.3, 1 with consideration of channel presumption with two types of rms delayed proliferation, which is 50nsec, 150nsec, for the performance analysis of STTC(Space-Time Trellis Code) using time-space code method appropriate for MIMO channel, and performance in the case where presumed channel value from long training column section is applied to according frame in a single frame. The result showed that BER brought SNR improvement of 1.0dB in 10$^{-3}$ when a was 0.3 than using only the long training column, and showed increase of general performance improvement for the sake of time average rather than the case without.

• The Mathematical Education
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• v.3 no.10
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• pp.7-20
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• 1965

One of the prerequisites for the improvement of the teaching of mathematics in our country is an improved curriculum-one which takes account of the increasing use of mathematics in science and technology and in other areas of knowledge and at the same time one which reflects recent advances in mathematics itself. In the new curriculum of mathematics, we have found the problems to teach the concept of sets at secondary level. The idea of a set is the most fundamental one in mathematics. So, this thesis contains the studies of the systematic analysis of sets in dealing with the traditional textbook. The scope of the work is limited to the fundamental ideas, and so it merely touches on the topics of the Concpets, Operations, Cardinal Numbers, Application of Logic, one-to-one Correspondence, Probability and so on. It provides only the essentials, definitions, proofs and some example which are already known and understood in their traditional context. It also presents at the appropriate stages the concepts required (illustrated by examples) in a much clearer fashion than classical teaching does. To compete a study of the sets covered in the textbook of each year, greater detail is needed at the appropriate level.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.24 no.3
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• pp.10-18
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• 2016

This paper deals with the Performance Based Logistics(PBL) application scheme pertaining to optimal maintenance program for logistics of Korean Fighter Experimental(KF-X) Project. For enhancement of the performance based logistics system application to KF-X program the selection of appropriate standards fit to maximize cost-cutting, a set of performance metrics fit for the purpose of the contract, foreign technology dependence of core equipments and parts were considered. Thus, selecting appropriate standards fit for Korean logistics environment, domestic maintenance enterprise for stable rate of operation of KF-X, a systematic reliability task that is able to measure quantitative combat capability are suggested.

• Journal of Information Technology Applications and Management
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• v.9 no.2
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• pp.81-106
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• 2002

As more organizations undertake IT-enabled business process reengineering(BPR), IT-enabled BPR projects become a major concern. Especially, one of IT, Enterprise Resource Planning System (ERP) is recognized as a revolution solution. But the success cases of ERP project are rarely reported. In this study, ERP implementation is defined as a IS implementation project based on BPR concepts To explore the issues of implementing ERP systems, a company implementing ERP successfully in Korea is selected. The research framework consists of four components: 1) strategic plan dimension , 2) organizational environment dimension, 3) implementation process dimension, and 4) IT dimension. On this framework, to implement ERP systems successfully, the analysis of the results clearly suggests appropriate planning, top management support, change management, appropriate methodology , ERP specialist commitment, management of standard process and master data, and the extent of IT localization.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.6
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• pp.54-60
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• 2014

In industry, several casting process are widely used to manufacture complex and accurate blank part of hard materials such as aluminum, casting steels, bronze and magnesium alloys which are difficult to manufacture in a blank shape. Even if the casting process does not high accuracy superior surface characteristics other machining process, the casting process is widely used in manufacturing blank part. Furthermore, it is difficult to select appropriate casting process a part among several casting process. for effective selection different process, a careful decision given casting application is necessary. An appropriate casting for a given material and shape condition must be selected for novice engineers in industry. In this paper, an expert system based on an analytic network process(ANP) is suggested for best selection of casting considering a prior interdependency effect among various factors such as material, geometry, process capability, economy and equipment.

• Transactions of Materials Processing
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• v.19 no.2
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• pp.132-137
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• 2010

In the multi-pass shape drawing process, the appropriate process design is very important to produce sound products. The reduction ratio, die angle, and the intermediate die shape are very important process variable of the multi-pass shape drawing. The aim of this study is the determination of the reduction ratio, die angle, and the intermediate die shape of the 2 pass shape drawing process for producing steering spline shaft. In this study, FE analysis, Taguchi method, and ANN(artificial neural network) were applied to determine the appropriate reduction ratio, die angle, and intermediate die shape. After the determination of the process variables, FE analysis and drawing experiment were performed to evaluate the effectiveness of the determined process variables. The dimensional accuracy of the final drawn spline shaft was evaluated by using 3D surface profiler and 3D laser digitizing system.

• Journal of Wellbeing Management and Applied Psychology
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• v.4 no.4
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• pp.35-41
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• 2021

Purpose: The purpose of this study is to identify the causes of odors generated in traditional markets and to suggest appropriate application technologies to solve them. Research design, data and methodology: In order to achieve the purpose of this study, complex malodors, TVOC, and hydrogen sulfide were measured three times at each point in Wonju-city, Gangwon-do using direct-reading odor measuring equipment in Joong-ang Traditional Market's Korean beef Alley, Sundae Alley, and Joong-ang Citizens Traditional Market. Therefore, the average value was compared with the emission standard and analyzed. Results: As a result of the study, complex malodors exceeded the emission standards at all points, and hydrogen sulfide exceeded the emission standards at all except for one point. Conclusions: The odor generated in the traditional market has various causes and low concentration, so it is necessary to reduce the odor by using an appropriate technology.

• Journal of Information Technology Applications and Management
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• v.28 no.4
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• pp.33-43
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• 2021

While youth unemployment has recorded the lowest level since the global COVID-19 pandemic, SMEs(small and medium sized enterprises) are still struggling to fill vacancies. It is difficult for SMEs to find good candidates as well as for job seekers to find appropriate job offers due to information mismatch. To overcome information mismatch, this study proposes the fine-turning model for bidirectional HR matching based on a pre-learning language model called BERT(Bidirectional Encoder Representations from Transformers). The proposed model is capable to recommend job openings suitable for the applicant, or applicants appropriate for the job through sufficient pre-learning of terms including technical jargons. The results of the experiment demonstrate the superior performance of our model in terms of precision, recall, and f1-score compared to the existing content-based metric learning model. This study provides insights for developing practical models for job recommendations and offers suggestions for future research.