• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1053-1056
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• 2008

An application of CSG (Constructive Solid Geometry) modeling technique in Machining Simulation is introduced in this paper. The current CSG model is based on z-buffer CSG Rendering Algorithm. In order to build a CSG model, frame buffers of VGA (Video Graphic Accelerator) should be used in term of color buffer, depth buffer, and stencil buffer. In addition to using CSG model in machine simulation Stock and Cutter Swept Surface (CSS) should be solid. Method to create a solid Cuboid stock and Ball-end mill CSS are included in the present paper. Boolean operations are used to produce the after-cut part, especially the Difference operation between Stock and CSS as the cutter remove materials form stock. Finally, a small program called MaSim which simulates one simple cut using this method was created.

• Journal of Korea Foundry Society
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• v.37 no.2
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• pp.38-44
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• 2017

Given that the conventional extrusion of high-strength Al alloys such as 7075 aluminum alloys is difficult due to their very low extrudability as compared to that of 6061 aluminum alloys, thixo-extrusion can be used to obtain a high-strength material easily at a lower extrusion pressure as compared to conventional extrusion. In this study, hot- and thixo-extruded 7075 aluminum alloys are prepared by a vertical forward extrusion process and their microstructures, hardness levels, and compressive properties are investigated. Hot-extruded alloy bars are assessed to obtain a microstructure elongated in the extrusion direction, whereas with thixo-extruded alloy bars, it was possible to obtain a microstructure having fine and equiaxed grains by dynamic recrystallization. The resulting isotropy and improved formability at the hot deformation temperature of the thixo-extruded alloy were attributed to the fine and equiaxed grains formed by the thixo-extrusion process.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1991.10a
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• pp.67-76
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• 1991

For several years, graduate students and faculty of the Engineering Systems Research Center at U.C., Berkeley have been studying new methods of planning and scheduling in a computer integrated manufacturing environment, with particular emphasis on large scale integrated circuit fabrication. One part of this work, focusing on short interval scheduling, uses simulation models as a primary research tool. We have built two versions of the same basic model (programmed in C) to study two different problems (one deals with machine down time and the other with setup times). These have proven to be efficient for studying particular problems, but are difficult and time consuming to modify. We are convinced that our research will be more effective: (1) if it were easier to build special purpose models tailored to the research question at hand; and (2) if we had better interfaces to graphics output. Commercially available factory simulators are inadequate for this research for a variety of reasons. Existing packages such as SIMKIT, SLAM, SIMAN and EXCELL have their own weaknesses. Typically, they are hard to develop and to modify. They do not allow for adding new dispatching decisions or release decision. Also, it is hard to add more machines to existing environment or change the route the product flows. For these various reasons, we had developed a new simulation package having flexibility and modularity. In this paper, based on experiences gained in the application of object oriented programming, we discuss unique features of the simulator developed in OOPS and ways to take advantage of features in developing and using manufacturing simulation software written in the OOPS

• Korean Journal of Artificial Intelligence
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• v.7 no.2
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• pp.13-17
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• 2019

Currently, the sports market continues to grow every year, and among them, professional baseball's entry income is larger than the rest of the professional league. In sports, strategies are used differently in different situations, and the analysis is based on data to decide which direction to implement. There is a part that a person misses in an analysis, and there is a possibility of a false analysis by subjective judgment. So, if this data analysis is done through artificial intelligence, the objective analysis is possible, and the strategy can be more rationalized, which helps to win the game. The most popular baseball to be applied to artificial intelligence to analyze athletes' strengths and weaknesses and then efficiently establish strategies to ease the competition. The data applied to the experiment were provided on the KBO official website, and the algorithms for forecasting applied linear regression. The results showed that the accuracy was 87%, and the standard error was ±5. Although the results of the experiment were not enough data, it would be possible to effectively use baseball strategies and predict the results of the game if the amount of data and regular data can be applied in the future.

• Knowledge Management Research
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• v.18 no.1
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• pp.67-81
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• 2017

As the important breakthrough continues in the field of machine learning and artificial intelligence recently, there has been a growing interest in the analysis and the utilization of the big data which constitutes a foundation for the field. In this background, while the economic value of the data held by the corporates and public institutions is well recognized, the research on the evaluation of its economic value is still insufficient. Therefore, in this study, as a part of the economic value evaluation of the data, we have conducted the economic value measurement of the data generated through the small business guarantee program of Korean Federation of Credit Guarantee Foundations (KOREG). To this end, by examining the previous research related to the economic value measurement of the data and intangible assets at home and abroad, we established the evaluation methods and conducted the empirical analysis. For the data value measurements in this paper, we used 'cost-based approach', 'revenue-based approach', and 'market-based approach'. In order to secure the reliability of the measured result of economic values generated through each approach, we conducted expert verification with the employees. Also, we derived the major considerations and issues in regards to the economic value measurement of the data. These will be able to contribute to the empirical methods for economic value measurement of the data in the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4569-4573
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• 2011

Resolver doesn't have a advantage to price in comparision with encorder. However, resolver is used to the case of detecting a absoluteness position and is used to a fine control in the place of having a stability by mechanic. The position by resolver and the method by speed detecting is applied by observer and have a part of processing analog signal. In this paper, we used the method which output signal of resolver is demodulated by cos and sin waveform and the demodulated analog signal is transmitted to controller. We designed the estimated on the program of a controller and observed the movement on the low speed.

• The KIPS Transactions:PartB
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• v.10B no.6
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• pp.579-586
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• 2003

In this paper, we propose a novel approach to employ emotional features to document retrieval systems. Fine emotional features, such as HAPPY, SAD, ANGRY, FEAR, and DISGUST, have been used to represent Korean document. Users are allowed to use these features for retrieving their documents. Next, retrieved documents are learned by classification methods like cohesion factor, naive Bayesian, and, k-nearest neighbor approaches. In order to combine various approaches, voting method has been used. In addition, k-means clustering has been used for our experimentation. The performance of our approach proved to be better in accuracy than other methods, and be better in short texts rather than large documents.

• Annual Conference of KIPS
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• 2005.05a
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• pp.553-556
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• 2005

ANSI C 언어는 UNIX 시스템에서 뿐만 아니라 DOS 환경에서 수행되는 C 컴파일러와 각종 지원 도구가 개발되어 보급됨으로써 오늘날 널리 사용되는 범용 프로그래밍 언어 중 하나이다. EVM(Embedded Virtual Machine)은 ANSI C 언어와 SUN사의 Java 언어 등을 모두 수용할 수 있는 임베디드 시스템을 위한 가상 기계이며, SIL(Standard Intermediate Language)은 EVM에서 실행되는 중간언어로 다양한 프로그래밍 언어를 수용하기 위해서 객체지향 언어와 순차적 언어를 모두 수용하기 위한 연산 코드 집합을 갖고 있다. EVM을 위한 ANSI C 컴파일러는 ANSI C 언어를 받아 들여 EVM의 중간 언어인 SIL 코드를 출력한다. ANSI C 컴파일러에서 어휘 분석과 구문 분석 과정에서 인식되는 명칭에 대해서 그 속성들을 수집하고 이용한다. 이 속성들은 명칭이 명시적으로 혹은 묵시적으로 정의되는 곳에서 심벌 테이블에 수집된다. 본 논문에서는 수집된 정보가 올바르게 되었는지 확인하기 위하여 심벌 테이블에 있는 정보를 다시 ANSI C 언어로 복원시키는 역변역기(detranslator)를 구현하였다.

• The KIPS Transactions:PartB
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• v.19B no.2
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• pp.135-148
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• 2012

This paper proposes a model for recognizing sentential paraphrases through Predicate-Argument Tuple (PAT)-based approximate alignment between two texts. We cast the paraphrase recognition problem as a binary classification by defining and applying various alignment features which could effectively express the semantic relatedness between two sentences. Experiment confirmed the potential of our approach and error analysis revealed various paraphrase patterns not being solved by our system, which can help us devise methods for further performance improvement.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.12
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• pp.771-777
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• 2000

This paper deals with the design and fabrication of a novel superconducting power supply system, and characteristics have been investigated through experiments. Superconducting power supply consists of rotating and static parts, and superconducting magnet. In this experiment, superconducting foils were placed in parallel within the static part of the machine, pumping currents were measured with respect to rotor speeds and excitation currents. In addition, in order to observe the rotating flux distribution in the superconducting foils, several hall-sensors were placed in it. With the flux distribution acquired, effect of the flux on the superconducting foil during the process of current pumping has been discussed. Also, the general operational characteristics of the superconducting power supply system have been investigated on the basis of the current and voltage data, and magnetic field values acquired through the experiments.