• 미생물학회지
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• 제37권4호
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• pp.259-264
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• 2001

S. typhimurium cadBA operon의 발현에는 산성 pH와 고농도의 lysine 등 적어도 두 가지의 세포외부 신호가 요구된다. pH와 lysine신호에 따른 cadBA 발현 조절 기작을 이해하기 위하여, Tn10삽입, 자발적 돌연변이, EMS돌연변이 등을 수행하여 JF2238과 cadA-lacZ의 발현특성에 차이를 보이는 돌연변이체를 선별하였다. cadBA의 양성적 조절자의 유전자인 cadC내의 돌연변이 중 cadC4 돌연변이는 pH-비의존성, lysine-의존성 발현을, cadC6 돌연변이는 pH-비의존성, lysine-비의존성 cadA-lacZ 발현을 나타내었다. 산성 pH, lysine이 없는 조건에서 cadA-lacZ 발현을 유도하는 cadR::Tn10과 cadR3 돌연변이체를 분리하여 cadR이 lysine이 없는 조건에서 cadBA 발현을 음성적으로 조절하는 음성적 조절자의 유전자임을 알 수 있었다. cadR 돌연변이체는 lysine의 독성 유사체인 thiosine에 대해 내성($Ts^{r}$)을 나타냈으며, E. coli의 lysP 클론을 갖고 있는 pLYSP에 의해 돌연변이 형질이 보상되었다. 또한 lysine decarboxylase (CadA)의 반응산물인 cadaverine은 cadC+ 균주에서 cadA-lacZ 발현에 억제효과를 나타냈으나, cadC 돌연변이에는 억제효과가 나타나지 않았다.

• Journal of Microbiology and Biotechnology
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• 제18권11호
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• pp.1755-1761
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• 2008

The present study revealed that Lrp, a leucine-responsive regulatory protein, is involved in the regulation of cadBA transcription through activation of $P_{cadBA}$. The influence of Lrp on $P_{cadBA}$ was mediated by CadC, and thereby, CadC was able to compensate for the lack of Lrp in the activation of $P_{cadBA}$. Western blot analyses and EMSA demonstrated that the cellular level of CadC was not significantly affected by Lrp, and that Lrp exerted its effect by directly binding to $P_{cadBA}$. These combined results suggested that CadC and Lrp function cooperatively to activate the $P_{cadBA}$ rather than sequentially in a regulatory cascade.

• Journal of Microbiology
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• 제39권2호
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• pp.109-115
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• 2001

Salmonella typhimurium possesses a cad operon, which contributes to an adaptive response against an acidifying environment. In Escherichia coli, the activation of the cad operon is dependent on cadC, which is located upstream of the operon. However, the activator of cad operon in S. typhimurium has not been known until now. In this study, we selected a putative cadC mutant by trasposon mutagenesis and cloned the cadc of S. typhimurium. Moreover, the cadC mutant was complemented by cadC clone. The cadC gene from S. typhimurium LT-2 consists of 1539 bp encoding a polypeptide ob 512 amino acids, and shows sequence similarity to cadC of E. coli with 53% identity and 67% similarity. The hydrophobicity profile of th S. typhimurim CadC sequence is very similar to E. coli CadC.

• 한국의류산업학회지
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• 제1권1호
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• pp.26-33
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• 1999

Nowadays the Apparel CAD is required in the clothing industries. So many domestic Apparel education institutions are interested in the Apparel CAD education. By investigating the present Apparel CAD education situations in college, the writer shows some data that are helpful to solve the problems in these parts. The purpose of this study is to give some helps in teaching the Apparel CAD in college. The results of this study are as followings, as the use of CAD systems is growing in the clothing industries, many colleges are concerned with the Apparel CAD. As a result, many colleges equip the Apparel CAD systems and the Apparel CAD is taught as special lectures, the part of other courses or regular course in many colleges. Apparel CAD should be taught as a regular course in colleges. And it should be taught systematically with Design CAD and Pattern CAD. But it is taught limitedly as special lectures, the part of other courses and post graduate studies. So it is impossible to educate the students professionally. As many colleges the CAD equipments are not opened to the students, the student's use of CAD systems are limited, so educational environment needs to improve to use CAD systems freely.

• 한국디지털건축인테리어학회논문집
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• 제1권1호
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• pp.24-30
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• 2001

This study conducts a questionnaire with undergraduate students in the Dept. of Architecture who will lead the architectural field in future, examines environment and perception of CAD in their home and universities and aims at supplying the data required for setting CAD educational index and building its use environment, and it could obtain the following results. Individual CAD environment of undergraduate students in the Dept. of Architecture reach a considerable level in hardware part, but they don't have the same level in software part as the hardware and use illegal copy programs. It is shown that they spend their time in using CAD for five to eight hours a week and its main purposes are to perform a project related to architectural design or make report requiring drawing. Major places using CAD are CAD room in university or public PC room equipped with CAD compared to their own houses and most of them have a negative recognition of the convenience of its use. Their satisfaction with CAD use is considerably high and when they submitted their assignments of architectural design project by means of CAD, they had a positive evaluation from their professors and they have such hopes that 'Korean Support Strengthening', 'lowering price through version supply for students' and 'diversification of design symbol' in CAD S/W, and especially, most of respondents have an intention to purchase the original goods when version only for students will be marketed in future. Accordingly, for a qualitative improvement of CAD environment for undergraduate students in the Dept. of Architecture, universities must be equipped with the various types of CAD S/W and Applications and students' opportunity to access them should be increased. In addition, a method which can enhance using convenience of CAD room and PC room is required and CAD related S/W developers must market the version for students which consider the reality of undergraduates in Korea properly with an appropriate price level in order to settle a sound S/W culture.

• 인터넷정보학회논문지
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• 제2권4호
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• pp.25-32
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• 2001

ASIC 설계용으로 이미 개발된 여러 CAD 도구 또는 추후 개발될 CAD도구들은 고유의 기능을 가지고 있으며, 서로 다른 환경에서 상이한 방식으로 운영되는 경우가 많다. 따라서 목표하는 최종적인 결과를 도출하기 위한 작업을 수행하기 위해서는 상호 밀접한 관계가 있는 여러 CAD도구들을 하나의 시스템에 통합하여 운영할 수 있는 통합 CAD Framework의 사용이 효과적이다. 본 논문에서는 주로 Unix Shell 상에서 개발된 기존의 국내외 CAD도구들을 Unix 운영체계의 X-windows라는 규격화된 그래픽 인터페이스 상에서 통합하여 수행할 수 있게 하는 기법을 소개한다. 이를 위해 메뉴 구성 및 실행 환경 설정을 위한 각종 파일 양식과 메타 언어를 정의ㆍ개발하였으며, 성능 확인을 위해 기존에 개발되어 있던 두 가지 CAD 도구들을 제안된 CAD Framework상에 통합시킨 Prototype 시스템을 개발하고, 이를 토대로 테스트하였다.

• 한국CDE학회지
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• 제2권1호
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• pp.1-6
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• 1996

CG 등의 컴퓨터 지원에 의한 도형처리 시스템 중에서 특히 설계제도를 지원하는 시스템으로서 CAD가 제공되고 있다. CAD에는 대형 컴퓨터를 플랫폼으로 하는 메인프레임(집중형) CAD와 EWS(엔지니어링 워크 스테이션)을 플랫폼으로 하는 EWS/CAD 및 퍼스널 컴퓨터를 베이스로 한 퍼스널 CAD가 있는데 최근에 컴퓨터의 고성능화와 소형화의 흐름에 따라 퍼스널 CAD가 CAD의 주류로 되고 있다. 그 큰 요인으로서 퍼스널 CAD는 하드웨어 및 소프트웨어를 포함한 시스템 가격이 EWS/CAD 등을 비롯한 다른 CAD에 비하여 저렴한 가격대라는 것과 조작성이 우수하다는 점을 들 수 있다. 또한 최근에는 OS(Operating System: 컴퓨터를 움직이기 위한 기본적 소프트웨어)의 주류가 싱글 유저.싱글 태스크인 MS-DOS(이하 DOS라 한다)에서 싱글 유저.의사 멀티 태스크인 MS-Windows(이하 Windows라 한다)에로 이행하고 있으며 퍼스널 CAD도 그에 대응하는 것으로 되고 있다. 여기서는 이 Windows에 대응하는 퍼스널 CAD의 최신의 기술동향 및 OS에 대하여 설명한다.

• 대한기계학회논문집A
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• 제30권5호
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• pp.488-495
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• 2006

The demand for the use of 3D CAD data over the Internet environment has been increased. However, transmission of 3D CAD data has delayed the communication effectiveness because of the CAD data size. Lightweight CAD file design methodology is required for rapid transmission in the distributed environment. In this paper, to derive lightweight CAD files from commercial CAD systems, a file translation system producing a native file is constructed first by using the InterOp and API of the ACIS kernel. Using the B-rep model and mesh data extracted from the native file, the lightweight CAD file with topological information is constructed as a binary file. Since the lightweight CAD file retains topological information, it is applied to the dimensional verification, digital mock-ups and visualization of CAD files. Effectiveness of the proposed lightweight CAD file is confirmed through various case studies.

• 한국실내디자인학회논문집
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• 제18호
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• pp.16-22
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• 1999

The purpose of this study is to analyze the drafting process by using AutoCAD for the basic course as well as to suggest the educational basic data of CAD in interior desigv. This research is to show not only practical use of CAD as a drafting tool function, but offering optimizing ways of AutoCAD command usage. The method used for this study is based on an analyzing of 6 types of total 98 types AutoCAD tutorial manual in CAD section of Kyobo book center. After the analysis of the AutoCAD command usage in creating floor plan, characteristics of drafting process is nearly the same as traditional drafting process. It means that traditional drafting process grafted on to computer aided drafting process. And the practical usage of AutoCAD command type is Draw, Modify, Format and View command in creating floor plav. That is emphasis on a specific functiov. Therefore, it should be developed basic course program which adapted various function of AutoCAD.

• 한국정밀공학회지
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• 제8권1호
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• pp.105-115
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• 1991

This paper describes an integrated CAD and CAPP system for prismatic parts of injection mold which generates a complete process plan automatically from CAD data of a part without human intervention. This system employs Auto CAD as a CAD model and GS-CAPP as an automatic process planning system for injection mold. The proposed CAD/CAPP system consists of three modules such as CAD data conversion module, manufacturing feature recognition module, and CAD/CAPP interface module. CAD data conversion module transforms design data of AutoCAD into three dimensional part data. Manufacturing feature recognition module extracts specific manufacturing features of a part using feature recognition rule base. Each feature can be recognized by combining geometry, position and size of the feature. CAD/CAPP interface module links manufacturing feature codes and other head data to automatic process planning system. The CAD/CAPP system can improve the efficiency of process planning activities and reduce the time required for process planning. This system can provide a basis for the development of part feature based design by analyzing manufacturing features.