• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.11
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• pp.2664-2675
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• 1993

In this paper, the effects of chip breaker configuration on cutting forces for various cutting conditions are investigated and a method for predicting cutting forces effectively for chip breaker insert in milling is described. Based on the shear plane model and the relevant equations already existing for the relation among the parameters, the method makes use of the analytic geometric approach considering the configuration of cutting too by a 3-dimensional coordinate transformation matrix. The groove type chip breaker insert is modeled to be a double rake insert, represented by the first radial rake angle, the second radial rake angle and the length of land, and the program analyzing the cutting forces is developed. The program capability is verified by comparing the results with the experimental ones for a single cutter; and in case of primary cutting forces, the results of simulation and experiments agree very well showing 2%~16.7% difference within the feed rate range investigated.

• Journal of Korea Multimedia Society
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• v.9 no.6
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• pp.709-719
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• 2006

To protect against unlawful reproductions and distribution, the current paper proposes a digital watermarking technique for architectural drawings produced using a CAD system. First, the POLYLINEs are extracted from the drawing; then, an adaptive algorithm is used to embed a watermark in the characteristics of each POLYLINE. Next, the CIRCLEs are embedded using an adaptive watermarking algorithm related to the radius of circle from drawing. The proposed watermarking scheme is robust to various attacks, such as the geometrical transformation. Additionally, the proposed method satisfies the requirement of transparency for CAD program. It used AutoCAD 2002, which is commonly used as a CAD program for experiments. Experimental results confirmed the robustness and invisibility of the embedded watermarks in several conversions of an architectural drawing.

• Journal of Korea Multimedia Society
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• v.4 no.6
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• pp.579-587
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• 2001

In this paper, we design and implement a parallel programming environment using graphicial user interface. Parallel program must be written according to the characters of various hardwares or programs. So it is difficult to write the parallel program. In this paper, we design and implement a parallel programming environment which solved this problem. The traditional parallel compiler provides the parallel information in the text environment. But this paper provides the parallel information using graphicial user interface so that the user may use it more easily. This parallel environment provide functions such as, data dependence analysis, CFG, HTF, and loop transformation.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.1
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• pp.59-66
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• 1989

The purpose of this study is to develop a personal computer aided 3-D geometric modeller. To perform this study, we set up a cube, cylinder, and a prism as primitives in the first segment of this study. By modelling the 3-D object through their transformation, addition, and subtraction, we proved the validity of the developed algorithm and its computer program. Some examples show the results of applying the program to model a few simple shapes of the machine parts. These results met the first aim of this study.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.10
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• pp.109-118
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• 1997

The purpose of this paper is to design cutter profiles for manufacturing rotors of screw compressor, which are based on universal milling machine. The surface profile of screw rotor which is helicoidal is derived as brief equation through the coordinates transformation of the section perpendicular to rotor axis. And the equations of contact lines between a cutter and the surface profile of screw rotor are derived. The computer program which can analyze the equation of contact lines numerically and design the cutter profiles of screw rotor is made, and verified through measuring screw rotors which are menufactured as the designed cutter by the computer program.

• Journal for History of Mathematics
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• v.17 no.4
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• pp.77-86
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• 2004

Felix Klein profoundly influenced mathematical developments throughout the world by showing a new direction for modem geometry. He also influenced the lives of excellent scientists like Einstein by reforming mathematical education. The first Felix Klein medal of the Internal Commission on Mathematical Instruction was awarded at ICME-10 in July of 2004. In this article, we discuss Klein's Erlangen Program and investigate his influence on modem mathematics and mathematical education with this medal as momentum.

• Management Science and Financial Engineering
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• v.18 no.2
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• pp.23-27
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• 2012

The problem of jointly determining a robust optimal bundle of price and order quantity for a retailer in a single-retailer, single supplier, single-product supply chain is considered. Demand is modeled as a decreasing power function of product price, and unit purchasing cost is modeled as a decreasing power function of order quantity and demand. Parameters defining the two power functions are uncertain but their possible values are characterized by ellipsoids. We extend a previous study in two ways; the purchasing cost function is generalized to take into account the economies of scale realized by higher product demand in addition to larger order quantity, and an exact transformation into an equivalent convex optimization program is developed instead of a geometric programming approximation scheme proposed in the previous study.

• Journal of Ocean Engineering and Technology
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• v.14 no.1
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• pp.95-101
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• 2000

In general, free form design depends on B-spline which is used for the generating hull lines in most of shipyards. But, nowadays, the NURBS method is applied to free form modeling method, which is able to more flexible transformation than B-Spline, and then became industrial standard in the various field. Therefore, this method has been considerably applied in new application fields which are required free form modelling. In this paper, the program called 2DSURF with 5 modules and developed for the generation of hull lines is described. It is examined whether the program can be applied to body lines, sheer lines, and half breadth lines.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.6
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• pp.7-14
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• 1998

A graphic user interface program for the design of vehicle suspension system is developed in this work. Graphic templates are designed by using a graphic language and a library and given to users for interactive data input. Several suspension types are graphically given, and the information of hard points can be directly provided on the graphic templates by users. The information is saved in a data structure which can be efficiently accessed, and transformed into another data format. The data transformation is for the interface to an analyzer by which suspension design characteristics can be calculated.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10a
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• pp.487-489
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• 1999

기존의 절차 중심적으로 개발되어진 시스템들은 일반적으로 오래 전에 개발되었으며 규모가 크고 구조화되어 있지 않아서 이해하기 어렵고 분석에 드는 비용이 크다. 그러나 그런 시스템들은 이미 운영환경에 관한 많은 비용과 중요한 정보들을 포함하고 있어서 시스템을 폐기하기 곤란하며 새로 개발하는 데에도 많은 비용과 시간이 요구된다. 이러한 절차 중심적 소프트웨어들이 제공하는 서비스를 계속 유지해가면서 그 시스템을 현대화하기 위한 방안으로 객체 지향 구조로의 소프트웨어 재공학이 요구되고 있다. 본 논문에서는 기존의 절차 중시적 소프트웨어 시스템을 객체 지향 소프트웨어 시스템으로 변환하는 방법에 관하여 논의한다. 이를 위해 프로그램에 내재되어 있는 타입 가시성 정보와 자료 가시성 정보를 그래프로 표현하고 이 그래프를 이용하여 객체를 추출하는 방법을 제시한다. 또한, 추출된 객체들을 클래스로 표현하고 클래스들 간의 관계를 파악하며, 클래스들을 기반으로 기존의 코드를 객체 지향 중심의 코드로 변환하기 위한 방법들을 연구한다.