• Korean Journal of Mathematics
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• 제29권2호
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• pp.387-393
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• 2021

In this paper, we introduce the notion of symmetric bi-derivations on subtraction algebra and investigated some related properties. We prove that a map D : X × X → X is a symmetric bi-derivation on X if and only if D is a symmetric map and it satisfies D(x - y, z) = D(x, z) - y for all x, y, z ∈ X.

• 미생물학회지
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• 제27권3호
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• pp.201-209
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• 1989

Mu dJ(km lac) peron 융합을 이용하여 Salmonella typhimurium에서 산소에 의해 조절되는 여러개의 새로운 유전자좌를 확인하였다. 산소가 있는 조건에서 유도된 9개의 유전자와 무산소조건에서 유도된 13개의 유전자가 분리되었다. 유전자 융합체들은 조절윤전자 oxrA의 control에 근거하여 2classe로 구분되었는데, class I 유전자들은 ozrA에 의해 조절되고, class II 유전자들은이 조절 유전자에 의해 영향을 받지 않았다. 몇몇 anti-lacZ 유전자 융합체들으 최소배지에서 발현되지 않았고, LB상에서나 혹은 CAA 첨가배지에서 그 활성을 나타내었다. 대부분의 유전자 융합체들은 nitrate와 fumarate에서 발현이 억제되었다. ani 유전자 가운데 3개의 유전자는 상호형질도입 빈도에 의해 각각 $59{\pm}0.14$ map unit (YK114), $64{\pm}0.2$ map unit(YK120), and $93{\pm}0.29$ map unit(YK112) 로 결정되었다.

• 한국정밀공학회지
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• 제20권2호
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• pp.176-183
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• 2003

The paper presents a feature recognition and segmentation method for surface approximation in reverse engineering. Efficient digitizing plays an important role in constructing a computational surface model from a physical part-surface without its CAD model on hand. Depending on its measuring source (e.g., touch probe or structured light), each digitizing method has its own strengths and weaknesses in terms of speed and accuracy. The final goal of the research focuses on an integration of two different digitizing methods: measuring by the structured light and that by the touch probe. Gathering bulk of digitized points (j.e., cloud-of-points) by use of a laser scanning system, we construct a coarse surface model directly from the cloud-of-points, followed by the segmentation process where we utilize the z-map filleting & differencing to trace out feature boundary curves. The feature boundary curves and the approximate surface model could be inputs to further digitizing by a scanning touch probe. Finally, more accurate measuring points within the boundary curves can be obtained to construct a finer surface model.

• Journal of applied mathematics & informatics
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• 제42권1호
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• pp.213-221
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• 2024

A family of sixth-order multiple-root solver have been developed and the special case of weight function is investigated. The dynamical analysis of selected iterative schemes with uniparametric polynomial weight function are studied using Möbius conjugacy map applied to the form ((z - A)(z - B))^m and the stability surfaces of the strange fixed points for the conjugacy map are displayed. The numerical results are shown through various parameter spaces.

• East Asian mathematical journal
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• 제14권2호
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• pp.269-279
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• 1998

For a codimension 1 submanifold in a Euclidean 2n-space, the degree of the gauss map mod 2 is the semi-characteristic of the manifold in $Z_2$ coefficient.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.116-121
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• 2001

Verification of tool collision is an important issue in die and mold machining. In this paper three functions of verification are schematically explained based on Z-Map model. The first function is getting a collision-free region when a tool assembly and a part surface model are given. The second function estimates the shortest length of cutter shank with that the tool cuts all of a region without collision. The last one is cutting simulation considering all parts of tool assembly as well as cutter blade. Those functions can be easily implemented by using several basic operators of Z-Map model which are explained also. Proposed approaches have enough accuracy to verify collision in reasonable computing time.

• 한국CDE학회논문집
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• 제2권3호
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• pp.161-174
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• 1997

In this paper, the techniques for graphic simulation of material removal process are described. The concepts of the bounding box and base plane are proposed. With these concepts, a real-time shaded display of a Z-map model being milled by a cutting tool following an NC path can be implemented very efficiently. The base planes make it possible to detect the visible face of Z-map model effectively. And the bounding box of tool sweep volume provides minimum area of screen to be updated. The proposed techniques are suitable for implementation in raster graphic device and need a few memories and a small amount of calculation. Proposed method is written in C and executable on MS-Windows95 and Window-NT.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.822-826
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• 1997

근래에 들어, 금형생산 시간의 단축과 고정밀도의 제품을 생산하기 위해 실가공전의 설계단계에서 금형 데이터를 수치적으로 검증할 필요가 높아지고 있다. 기존의 저가형 CAM시스템에서 사용된 경로표시법으 로는 이러한 검증이 불가능하기 때문에 새로운 방법의 도입이 필요하며 모의가공 형상의 표현에서도 비매 개변수형 곡면을 이영하는 방법이 널리 사용되고 있다. 본 연구는 3축 금형가곡에 사용되는 볼앤드밀, 평 엔드밀 공구에 대해 Z-map을 기반으로 절삭부위를 비매개변수형 곡면으로 모델링하여 모의가공을 수행하 고자 한다. 또한, 새로운 backeting영역지정 방법을 사용하여 모의가공의 효율을 높였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.3-6
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• 2002

This paper presents the cutting simulation system for prediction and regulation of cutting force in CNC machining. The cutting simulation system includes geometric model, cutting force model, and off-line fred rate scheduling model. ME Z-map(Moving Edge node Z-map) is constructed for cutting configuration calculation. The cutting force models using cutting-condition-independent coefficients are developed for flat-end milling and ball-end milling. The off-line feed rate scheduling model is derived from the developed cutting force model. The scheduled feed rates are automatically added to a given set of NC code, which regulates the maximum resultant cutting force to the reference force preset by an operator. The cutting simulation system can be used as an effective tool for improvement of productivity in CNC machining.

• 충청수학회지
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• 제31권1호
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• pp.47-52
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• 2018

Let ${\delta}$ be a derivation in a noetherian integral domain A. It is shown that a natural map induces a homeomorphism between the spectrum of $A[z;{\delta}]$ and the Poisson spectrum of $A[z;{\delta}]_p$ such that its restriction to the primitive spectrum of $A[z;{\delta}]$ is also a homeomorphism onto the Poisson primitive spectrum of $A[z;{\delta}]_p$.