• 소성∙가공
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• 제7권3호
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• pp.260-273
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• 1998

A new blank design method is proposed to predict the optimum initial blank shape in the sheet metal forming process. The rollback method for blank shape design takes the difference between final deformed shaped and target contour shape into account. Based on the method a computer program composed of blank design module FE-analysis program and mesh generation module is developed. The rollback method is applied to square cup drawing process with the flange of unifiorm size around its periphery to confirm its validity. The optimum initial blank shape is obtained from an arbitrary square blank after three modification. Good agreements are recognized between the numerical results and the published results for initial blank shape and thickness strain distribution. The optimum blank shape for two parts of automobile sub-frame is designed, The thickness distribution and the level of punch load is improved. Also the method is applied to design the weld line in the tailor-welded blank. It is concluded that the rollback method is an effective and convenient method for an optimum blank shape design.

• Journal of Electrical Engineering and Technology
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• 제10권4호
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• pp.1471-1479
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• 2015

A major portion of the capital costs in the present day power transmission systems are due to the cost of equipment and construction process. Transmission utilities in the recent years are drawing greater attention towards performing life cycle costing studies for cost management and decision making. However, the data involved in these studies are highly uncertain and the effect of these uncertainties cannot be directly included in the study process, resulting in inaccurate solutions. Interval mathematics provides a method for including these uncertainties throughout the cost analysis and provides final solution range in the form of intervals. In this regard, it is essential and extremely important that significant research has to be carried out in understanding the principles of life cycle costing methodology and its applicability to cost analysis of transmission lines along with uncertainties involved in the cost assessment process. In this paper, economic analysis of power transmission lines using interval mathematics has been studied. Life cycle costing studies are performed using net present value analysis on a range transmission lines used in India and the results are analyzed. A cost break even analysis considering right of way costs was carried out to determine the point of economy indifference.

• 식물분류학회지
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• 제44권1호
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• pp.9-12
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• 2014

Talipariti simile (Blume) Fryxell (아욱과)을 베트남 미기록 종으로 처음으로 보고한다. 본 종은 줄기에 털이 없는 유사종인 T. macrophyllum (Roxb. ex Hornem.) Fryxell 와는 달리 줄기에 자색을 띠는 작은 털이 있으며, 탁엽은 피침상 타원형으로 크기가 작으며, 삭과는 난형이며 끝이 뾰족하지 않거나 부리모양이 아니다. 종 동정을 위한 분류학적 기재, 식물도해, 원색사진을 첨부하였다. 또한 유사 종들과의 비교를 위한 검색형질을 제시하였다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1998년도 춘계학술대회논문집
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• pp.185-195
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• 1998

A new blank design method is proposed to predict the optimum initial blank shape in the sheet metal forming process. The rollback method for blank shape design takes the difference between final deformed shape and target contour shape into account. Based on the method, a computer program composed of blank design module, FE-analysis program and mesh generation module is developed. The rollback method is applied to square cup drawing process with the flange of unifiorm size around its periphery to confirm its validity. The optimum initial blank shape is obtained from an arbitrary square blank after three modifications. Good agreements are recognized between the numerical results and the published results for initial blank shape and thickness strain distribution. The optimum blank shape for two parts of automobile sub-frame is designed. The thickness distribution and the level of punch load is improved. Also, the method is applied to design the weld line in the tailor-welded blank. It is concluded that the rollback method is an effective and convenient method for an optimum blank shape design.

• 건축역사연구
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• 제6권3호
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• pp.89-108
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• 1997

This study has been researched mainly about the gradual changing patterns of site plan and plan layout of 17 sampling traditional houses in kyungpuk province during the time period of 1877-1945. The objective of this study is to closely examine the characteristics of locality and trend of the times. Survey and Measured drawing, personal interviews with clients has been carried out and the result is as down below; 1.The certain changes have shown that the furnace in sarangchae(outer wing for men) in ㅁ shaped and ${\ulcorner}$ ${\lrcorner}$ shaped houses served only for that purpose and inner gate has been built in sideward of sarangchae. 2.As living standard was upgraded storage space and size of the rooms got bigger. On the other hand, spacial formation was emphasized by its function accordding to house activities and living circulation because the family members in direct line became reality of the time. 3.The modernistic thought of rationalism and convenience are well expressed in the plan layout and house living as a whole.

• 한국조경학회지
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• 제27권4호
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• pp.137-142
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• 1999

The purpose of this study is to develope a CAD-based tool for rasterization of polygonal vector map in AutoCAD. To identity the layer property of polygonal entity with user-defined coordinates as topology, algorithm in processing entity data of selection set that intersected with scan line was used, and the layers were extracted sequentially by sorted intersecting points in data-list. In addition to the functions for querying and modifying topology, two options for mapping were set up to construct plan projection type and to change meshes' properties in existing DTM data. In case of plan projection type, user-defined cell size of 3DFACE mesh is available for more detailed edge, and topological draping on landform can be executed in case of referring DTM data as an AutoCAD's drawing. The concept of algorithm was simple and clear, but some unexpectable errors were found in detecting intersected coordinates that were AutoCAD's error, not the utility's. Also, the routines to check these errors were included in algorithmic processing. Developed utility named MESHMAP was written in entity data control functions of AutoLISP language and dialog control language(DCL) for the purpose of user-oriented interactive usage. MESHMAP was proved to be more effective in data handling and time comparing with GRIDMAP module in LANDCADD which has similar function.

• 공학교육연구
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• 제17권6호
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• pp.53-61
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• 2014

This study aims to identify on the possibility of the convergence education in engineering. Delphi survey on a panel of experts was chosen to be the main methodology for this study, drawing the main factors of convergence education in engineering. From Oct. 10 to Nov. 25, 2013, a three-round Delphi survey was implemented to collect data. A panel of eighteen experts were involved in this survey. For statistical processing, descriptive statistics including frequency, percentage, mean and standard deviation were carried out along with internal reliability test on the survey instrument. First, the possible convergence of disciplines in engineering were found to Design, Industrial design, ICT, Health care services, Video media, Business and Administration, Organizational psychology, Sociology, Humanities and Aesthetics. Second, the convergence education factors to be most important demanded creativity, idea generation techniques such as the expression of thought communication skills, technical expertise in the field per line, understanding of basic knowledge, verification of common elements among different disciplines, understanding of other disciplines fusion in engineering, artistry and imagination, etc. Third, requirements for the talented person of convergence were the open mind and enthusiasm, creative imagination, accept the opinions of others, skills capacity as a creative expression, and challenges. Above-mentioned requirements are found to be the necessary elements for convergence education.

• 식물분류학회지
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• 제46권1호
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• pp.55-59
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• 2016

Justicia kampotiana Benoist (쥐꼬리망초과)를 베트남 미기록종으로 보고한다. 본 종은 유사종인 J. ingrata Benoist와 달리 외화관에 털이있으며, 화통은 판연 보다 약간 길고 화병보다는 아주 짧다. 종 동정을 위한 기재, 그림도해 및 컬러사진과 함께 본 종과 유사종의 비교를 위한 검색형질들을 제시하였다.

• 제어로봇시스템학회논문지
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• 제17권4호
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• pp.362-367
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• 2011

The collision-free path of a manipulator should be regenerated in the real time to achieve collision safety when obstacles or humans come into the workspace of the manipulator. A probabilistic roadmap (PRM) method, one of the popular path planning schemes for a manipulator, can find a collision-free path by connecting the start and goal poses through the roadmap constructed by drawing random nodes in the free configuration space. The path planning method based on the configuration space shows robust performance for static environments which can be converted into the off-line processing. However, since this method spends considerable time on converting dynamic obstacles into the configuration space, it is not appropriate for real-time generation of a collision-free path. On the other hand, the method based on the workspace can provide fast response even for dynamic environments because it does not need the conversion into the configuration space. In this paper, we propose an efficient real-time path planning by combining the PRM and the potential field methods to cope with static and dynamic environments. The PRM can generate a collision-free path and the potential field method can determine the configuration of the manipulator. A series of experiments show that the proposed path planning method can provide robust performance for various obstacles.

• 한국군사과학기술학회지
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• 제16권1호
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• pp.27-33
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• 2013

Helmet Mounted Display(HMD) has great advantages on the navigation and mission symbologies for the pilot's forward looking display and, therefore, has been remarkably drawing attention as the up coming display of the next generation aircraft. The essential technology to process the Line of Sight-Foward(LOS-F) data in real-time is to estimate exact helmet situation and position. In this paper, we research a acoustic helmet tracking technique. For the reason that mechanical acoustic noises might interfere with Helmet Tracking System(HTS) and unnecessary acoustic noises are inevitable when using acoustic technique, this approach has not been adapted. In order to overcome this problem. We propose that acoustic wave of which the wave length is longer than audio frequency and, especially, we used beating signal envelope which is composed of two close high frequency.