• Journal of the Korean Society for Precision Engineering
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• v.16 no.1 s.94
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• pp.26-33
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• 1999

Automatic monitoring of cutting process is one of the most important technologies for increasing the stability and the reliability of unmanned manufacturing system. In this study, basic methods which use the acoustic emission (AE) signals and cutting forces were proposed to monitor flank wear (width of flank wear) quantiatively. First, in order to detect flank wear, it was investigated that the influence of cutting conditions, that is, cutting velocity, feed and depth of cut, on AE signals (${AE_rms}$) and cutting forces. Furthermore, the relation between flank wear and the measured signals (${AE_rms}$, cutting force) was discussed.

• Journal of the Korean Regional Science Association
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• v.15 no.3
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• pp.33-51
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• 1999

After the 1997 currency crisis, the real estate prices had been rapidly dropped and the deregulation in the Korean real estate merket has been performed. It is analyzed whether these transactions caused a structural change in real estate market, or not. The Pettitt test shows there exists a turing point in real estate prices in 1998. It is found that the degrees of co-movement between the change in real estate prices and real GDP growth rate are increased. Consequently, the factor, represented as real GDP growth rate, determining the market fundamental of real estate prices will effect on the behavioral pattern and the real estate prices in the long run. While the factors determining the portfolio selection behaviors, such as interest rate and stock prices, will cause short-term variations.

• The Magazine of the IEIE
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• v.11 no.1
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• pp.39-53
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• 1984

계산량 이론을 역사적으로 개관하였다. 문제의 본질적 계산복잡도를 정의하는 것 및 계산량의 상계, 하계를 증명하는데 있어서의 기본적인 문제점에 중점을 두었다. 확률적 계산 및 병열계산에 관해서도 논하였다. 이 강연은 계산량(계산복잡도, computational complexity)이론에 관한 튜링상 수상 강연으로서는 두번째의 것이다. 첫번째 것은 1976년에 Michael Rabin의 것이다. Rabin의 탁월한 기념강연을 지금 다시 읽어보면 그 이래로 이 분야에 얼마나 많은 연구가 이룩되었는지를 절감하게 된다. 이 개설에서는 계산량에 관한 연구가 1960년에 시작된 이래 가장 중요하고 흥미를 끄는 결과라고 생각되는 문제에 대해서 언급하고자 한다. 이와같이 광범한 분야에 있어서는 화제의 선택이 개인적인 취향에 치우치는 것을 피할 수는 없지만 나로서는 어떠한 기준으로 보더라도 기본적이라 할 수 있는 논문은 포함시키도록 하겠다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.862-865
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• 2000

The object of this paper is to evaluate the surface roughness using the experimental equation of surface roughness, which is developed in turning by an orthogonal array method. $L_9{3^4}$ orthogonal array method, one of fractional factorial design has been used to study effects of main cutting parameters such as cutting speed, feed rate and depth of cut, on the surface roughness. And the analysis of variance (ANOVA)-test has been used to check the significance of cutting parameters. Using the result of ANOVA-test, the experimental equation of surface roughness, which consists of only significant cutting parameter - feed rate, has been developed. The coefficient of determination of this equation is 0.962.

• Journal of Information Technology Applications and Management
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• v.17 no.3
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• pp.43-56
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• 2010

Completely Automated Public Turing test to tell Computers and Humans Apart or CAPTCHA has received remarkable attention. Deciphering distorted texts is still a human task. The current CAPTCHA mainly requires users to read English alphabets. As such, Thai CAPTCHA may be the choice for Thai online practitioners. However, no published work has examined how Thai online practitioners perceive CAPTCHA. This study thus attempts to fill this void. Based on the 112 number of usable online questionnaire submission, Thai online practitioners are all aware of CAPTCHA. Also, nine out of ten samples identified correctly the prime benefits of CAPTCHA. Using exploratory factor analysis, their attitude towards CAPTCHA was classified into two dimensions. They perceived (1) drawback of general CAPTCHA and (2) feasibility of Thai CAPTCHA. In addition to extending our insight into application of CAPTCHA, policy-makers responsible for electronic commerce in Thailand could initiate plans in response to Thai online practitioners' perception.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.4
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• pp.33-39
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• 2001

During the turning of the workpiece, cutting heat causes thermal deformation of the cutting tool which influences the surface characteristics of the machined part. This paper presents a study of thermal deformation of the cutting tool. For this purpose, cutting tool is modeled based of Pro/Engineering and the thermal deformation is simulated by means of the finite element method. The thermal effect on the surface roughness profile is simulated by using surface-shaping system. It has been shown that the results of simulation are similar to those of experiment.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.1179-1185
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• 2003

시뮬레이션 상의 입력모델에 대한 기존의 연구는 과거의 자료를 바탕으로 선형의 모수적인 (parametric) 모형을 개발하는데 초점을 두고 있다. 그러나 이 경우에는 입력이 매우 복잡한 형태를 가지면 모수적인 모형을 잦는 것이 불가능해지므로 비모수적인(non-parametric) 접근방법이 절실한 실정이다 예로 인터넷 트래픽 모델의 시뮬레이션 수행시 입력으로 제공되는 단위 시간당 요구되는 웹 페이지의 수 같은 경우 데이터들 간데 종속관계가 매우 심하고 복잡하여 모수적 모형을 세우는데 어려움이 있다. 이러한 시스템들을 시뮬레이션 방법으로 분석 하고자 할 때, 기존의 trace-driven 시뮬레이션 방법이나 모수적 모형을 찾아 다수의 사실적인 시뮬레이션 입력 자료를 확보하는 것은 현실적으로 어려움이 있다. 따라서. 비모수적인 방법으로 다수의 사실적인 시뮬레이션 입력 자료를 생성하는 것이 필요하다. 이러한 비모수적인 방법에 대한 평가기준 설정은 시뮬레이션 상의 입력 모델에 대한 타당성을 제시한다는 점에서 또한 매우 중요하다. 본 논문에서는 붓트스트 랩의 방법중의 하나인 임계값 붓트스트랩을 이용하여 시뮬레이션 입력 자료 생성 방법을 개발하였고 Turing test를 통해 붓스트랩으로 생성산 입력 시나리오를 검증하였다.

• The Korean Journal of Community Living Science
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• v.12 no.2
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• pp.15-32
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• 2001

This research was performed to examine the ratio of blindness to the child care environment and compare the evaluation of it among principals, teachers and mothers. Data were collected from questionnaires completed by respondents of this research were 37 principals, 37 teachers and 261 mothers of infants and toddlers at child care centers in Incheon, Korea. Cross tabulation, one-way ANOVA and Duncan's Multiple Range Test were utilized to analyze the data. In almost all of the items about the child care environment, mothers showed higher degrees of blindness than principals and teachers. In most of the items, mothers'evaluations were higher than those of principals and teachers. As a result, the researchers recognize a pressing need far programs far parents to improve the quality of child care.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.891-894
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• 1997

The asphericals lenses are used as objective lens of optical pickup. To examine the design factor the sample product is made before manufacturing of injection mould of lens. The optimum cutting condition of PMMA lens sample with ultra precision SPDT, he main spindle sped, the depth of cut, the feedrate are found. The demanded surface roughness 10nm Ra, aspherical form error 0.5${\mu}{\textrm}{m}$ P-V for aspherical lens of optical data storage device are satisfied.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.975-978
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• 2003

This paper presents an artificial intelligent model for a soccer robot. We classified soccer robot as artificial intelligent model into three elemental groups as instinct, intuition, reason. Instinct is responsible for keeping the ball, driving or rushing toward the ball. This is very simple fundamental action without regard to associates and enemies. Intuition contributes to the fast/slow moving and simple basic turing to get near to the ball and to make a goal noticing associates and enemies. Reason is the most intelligent part. The law of reason is not simple relatively with instinct and intuition. We also compared nerve system and muscles of human being model with controller and motor of physical soccer robot model individually. We had designed several algorithms and made programs th investigate effects and control soccer robot.