• 한국CDE학회논문집
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• 제4권2호
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• pp.87-99
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• 1999

We developed a Part Information Brokering System, namely PIBS, that can inter-link part suppliers and buyers using WWW(World Wide Web). The major contribution of this paper is that the system provides a 3D collaboration environment that enables multiple users to share the same workspace where they cooperatively manipulate part features in real time. PIBS carries out two major functions: one to maintain part data in a part library, and the other to provide the means for the clients to cooperate. An object-oriented database is used for the part library which stores apart information registered by part suppliers. VRML(Virtual Reality Modeling Language) the ISO standard for 3D visualization on WWW, is used to represent 3D part models. Several Java programs have been implemented to support synchronous and a synchronous communication of the 3D models. Once the users are interconnected through the system, a user's manipulation of part objects is transparently and instantaneously transmitted to the others. This means that all the participants can are the same view and movement of the 3D part models. Since the system is developed using a Java applet-server architecture, it requires no additional software other than standard web browser. The prototype system has been successfully implemented, and demonstrated its applicability to virtual 3D part information sharing.

• Journal of Ginseng Research
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• 제25권2호
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• pp.89-93
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• 2001

This study was carried out to investigate a point of difference in chemical characteristics between normal and inferior Korean red ginseng (Naeback red ginseng=red ginseng with white part of clear boundary in phloem and/or xylem of ginseng body, saengnaeback red ginseng=red ginseng with white part of indistinct boundary). content of total sugar as chemical components of naeback and saengnaeback part from Korean red ginseng were less than that of normal part, and content of reducing sugar in normal and saengnaebakc part showed higher than that of naeback part. But differences in content of total phenolic compounds was not found. The content of crude saponin in normal part was highest, amounts of ginsneoside were about same. The content of constituent amino acid in normal part was about 2 times as compared with those in naeback and saengnaeback part in red ginseng. Among the various amino acids, the contents of arginine, glutamic acid, aspartic acid, leucine and alanine of normal and naeback part were higher than others, but in saengnaeback proline, glutamic acid, aspartic acid, threonin and glycine etc. were higher. In the total amount of free amino acids, those in normal, naeback and saengnaeback part were about the same one another, and arginine, glutamic acid and aspartic acid were major free amino acids.

• 대한산업공학회지
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• 제28권4호
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• pp.360-367
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• 2002

The machine-part group formation is to group the sets of parts having similar processing requirements into part families, and the sets of machines needed to process a particular part family into machine cells. The purpose of this study is to develop a two-phase machine-part group formation algorithm based on Self-Organizing Maps (SOM). In phase I, it forms machine cells from the machine-part incidence matrix by means of SOM whose output layer is one-dimension and the number of output nodes is the twice as many as the number of input nodes in order to spread out the input vectors. In phase II, it generates part families which are assigned to machine cells by means of machine ratio related with processing part and it gives machine-part group formation. The proposed algorithm performs remarkably well in comparison with many well-known algorithms for the machine-part group formation problems.

• 항공우주시스템공학회지
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• 제7권2호
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• pp.42-46
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• 2013

In 2010, Airworthiness standard for VLA(Very Light Airplane) category was newly introduced as KAS Part VLA. KAS Part VLA is an adaption of EASA CS-VLA which was developed to reduce unnecessary burden of manufacturer of very light, simple, single-reciprocating-engine/propeller powered airplanes having low stall speeds by tailoring some requirements of Part 23. In this paper, difference and similarity of structural requirements between Part 23 and VLA was analyzed.

• 한국연소학회지
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• 제21권4호
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• pp.16-22
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• 2016

Pressure and temperature variations in a shock tube have been studied numerically by changing the diameter ratio of a driven part to a driver part. There are five cases where the adopted diameter ratios are 40%, 50%, 60%, 80%, and 100% respectively. The diameter of the driver part remains unchanged meanwhile the shock tube driven part diameter increases from 40% to 100% of the driver part. In the 100% ratio case, the driver part and driven parts have the same diameter of 66.9 mm. As the diameter ratio decreases, the pressure in the shock tube and available test time are increased.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.848-851
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• 2002

In the field of automobile industry, lightweight problems are very important in terms of reducing fuel and protecting environment. To satisfy these demands, the attempt to substitute aluminum automobile components for cast steel part has been actively carried out. To fabricate the aluminum automobile suspension part that has the same mechanical properties with cast steel part, design conditions such as shape and dimension of part shall be established. Therefore in this study, shape and dimension conditions of suspension part were proposed. Aluminum automobile suspension part was fabricated by semi-solid die-casting process under the obtained design conditions. Moreover to evaluate the possibility of application to the automobile component, stress and fatigue analysis were performed by using ABAQUS S/W and compared with those of conventional automobile suspension part.

• 대한기계학회논문집
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• 제18권11호
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• pp.3091-3097
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• 1994

An expert system for NC part programming of NC lathe (ESPP-1) is developed as a part of Computer-Adied Manufacturing system. Conventional computer-assisted part programming system essentially requires an NC part programmer who is an expert in NC part programming. But the developed ESSP-1 can allow an inexperienced person to make an excellent NC data for the NC Lathe without any problem, since the system has a knowledge base composed of EIA and ISO NC code, feed rate, spindle speed, machining coordinates selection, and tool selection etc., which were directly evoked from some skilled NC part programmers, and referenced some machining handbooks. This paper discusses the algorithm of the expert system for NC part programming of the NC lathe (ESPP-1) and the performance comparisons between the developed expert system and the conventional system.

• 대한산업공학회지
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• 제30권3호
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• pp.175-180
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• 2004

The machine-part group formation is to group the sets of parts having similar processing requirements into part families, and the sets of machines needed to process a particular part family into machine cells using grid computing. It forms machine cells from the machine-part incidence matrix by means of Self-Organizing Maps(SOM) whose output layer is one-dimension and the number of output nodes is the twice as many as the number of input nodes in order to spread out the machine vectors. It generates machine-part group which are assigned to machine cells by means of the number of bottleneck machine with processing part. The proposed algorithm was tested on well-known machine-part grouping problems. The results of this computational study demonstrate the superiority of the proposed algorithm.

• 전자공학회논문지SC
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• 제43권2호
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• pp.33-39
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• 2006

본 논문에서는 휴대용 적외선 야시경의 소형 경량화 및 저전력을 위한 전자회로부를 설계하였다. 설계한 전자회로부는 전압자동변환부와 전원공급부로 구성한다. 전압자동변환부는 배터리, 스위치부, 승압부, 전압선택부 등으로 구성한다. 전원공급부는 고광원 감지회로, 배터리 전압감지회로, 적외선 발광회로, 연결감지회로, 공급제어회로 등으로 구성한다. 설계한 전자회로부의 성능은 AN/PVS-14에 비하여 소모전력 및 상온 연속사용 시간에서 우수하였다.

• 한국CDE학회논문집
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• 제9권1호
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• pp.51-61
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• 2004

Mechanical parts are often grouped into part families based on the similarity of their shapes, to support efficient manufacturing process planning and design modification. The 2-part sequence papers present similarity assessment techniques to support part family classification for machined parts. These exploit the multiple feature decompositions obtained by the feature recognition method using convex decomposition. Convex decomposition provides a hierarchical volumetric representation of a part, organized in an outside-in hierarchy. It provides local accessibility directions, which supports abstract and qualitative similarity assessment. It is converted to a Form Feature Decomposition (FFD), which represents a part using form features intrinsic to the shape of the part. This supports abstract and qualitative similarity assessment using positive feature volumes.. FFD is converted to Negative Feature Decomposition (NFD), which represents a part as a base component and negative machining features. This supports a detailed, quantitative similarity assessment technique that measures the similarity between machined parts and associated machining processes implied by two parts' NFDs. Features of the NFD are organized into branch groups to capture the NFD hierarchy and feature interrelations. Branch groups of two parts' NFDs are matched to obtain pairs, and then features within each pair of branch groups are compared, exploiting feature type, size, machining direction, and other information relevant to machining processes. This paper, the second one of the two companion papers, describes the similarity assessment method using NFD.