• Electric Engineers Magazine
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• s.161
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• pp.40-43
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• 1996

프로그래머블 컨트롤러(PC)라고 하는 제어장치가 1970년대말부터 급격하게 사용되기 시작된 것은 주지하는 바와 같다. 그후 어느 조사에 의하면 PC의 연간 신장률이 $30\~40\%$나 됐다고 한다. 본고는 앞으로 1년간에 걸쳐 (1) 종래 전자 릴레이 시퀀스 제어기술 영역의 업무에 종사해 왔지만 PC와 접하지 않으면 안되게 된 사람과 (2) 새로 학교나 직업훈련소를 나와 앞으로 PC를 취급하는 직장에 종사하게 된 사람들을 대상으로 연재를 시작하는 것이므로 시퀀스 제어의 동작, 회로, 회로도를 보는 방법, 그리는 방법에 대해서 일단의 지식과 경험이 있어야 하는 것이 전제조건이 된다. 본 연재는 종래의 시퀀스 제어회로를 PC의 프로그램으로 표현하려면 어떻게 생각하면 되는가를 중심으로 완결된 프로그램을 들어 기술한다. 즉, 지금까지 전선으로 릴레이간을 배선하여 제어회로를 작성하고 있던 것을 PC의 프로그램으로 만드는(이것을 소프트 와이어드라고도 한다) 방법이 설명되고 있다. PC 프로그램 작성은 용이성이 필요 조건이 된다. 이를 위해 본고에서는 명령의 수를 제한하고 프로그램의 논리구조가 명확해지는 방법을 사용하였다. 본 연재는 앞에서 언급한 바와 같이 소형 PC를 릴레이 대신 사용하는 방법에 대해서 기술하는 것으로서, 시퀀스 제어계의 설계에 관해서는 취급하고 있지 않다. 그것은 별차원의 것이기 때문이다. 그러나 PC로 시퀀스 제어회로를 간단히 작성하게 되면 다음은 회로를 어떻게 해서 만드는가 또는 회로를 만드는 것이 아니고 기계의 움직임을 그대로 표현하고 그것을 프로그램으로 하는 것같은 이른바 설계법으로 PC의 과제가 이동해 하는 것은 확실하다. 소프트 와이어드화의 힘이 붙으면 다음은 시퀀스 제어계의 동작 표현법, 설계법으로 흥미가 옮겨 가게 된다. 본고가 이것으로의 교량역할이 된다면 다행이겠다.

• Journal of the Korea Institute of Building Construction
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• v.17 no.1
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• pp.31-37
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• 2017

The use of half PC slab has been increasing to shorten construction period. Because the drying shrinkage of topping concrete is restrained by PC slab, the tensile stress is generated at the topping concrete and the cracks can be occurred at the topping concrete due to drying shrinkage. Therefore, it is important to predict the tensile strain of half PC slab due to drying shrinkage to improve the quality of half PC slab. However, there is no studies on prediction of shrinkage behavior of half PC slab yet. Therefore, in this study, half PC slab was made, and the predictability of tensile strain generated at half PC slab due to drying shrinkage was investigated. The step by step method considering creep was used to estimate the tensile strain of half PC slab. In result, good agreement was obtained between the analytical and experimental values.

• 정보화사회
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• s.81
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• pp.23-25
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• 1994

최근 PC통신망에 게재된 "이적표현물"의 국가보안법 적용을 중심으로 "불온통신물"게재에 대한 법적 문제를 살펴본다.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.3
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• pp.19-25
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• 1999

The photoreceptor films with double layer structure were prepared by the plasma polymerization and the dip-coating method. The blocking layer was coated with A1$_2$O$_3$ on the Al substrate and the charge generation layer was formed by H$_2$ phthalocyanine (H$_2$Pc). Poly 9-Vinylcarbazole was used as a charge transport layer. H$_2$Pc film prepared by the vacuum evaporation had absorption peaks on 613.6[nm] and 694.8[nm], and H$_2$Pc film prepared by the plasma polymerization had a dull peaks between 600 and 700[nm]. The surface potential of PVCz increased with increasing the applied voltage and the thickness of PVCz. The dark decay characteristic, the light decay time and the residual time increased with increasing the thickness of PVCz. The surface charge of PVCz of 15[${\mu}{\textrm}{m}$] thickness was 134[nc/$\textrm{cm}^2$] at the surface potential of -600[V] and the charge generation efficiency of H$_2$Pc was 0.034.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05b
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• pp.981-986
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• 1995

이 논문의 목적은 축대칭 프리스트레스트 콘크리트 탱크의 시간의존성 유한요소해석법을 제안하는 것이다. 오늘날 PC구조물은 교량, 포장판, 해상구조물, 원자로 격납구조물, 대규모 액체저장용 탱크 등 여러 형태의 구조물에서 그 사용 예를 쉽게 찾아볼 수 있다. 특히 본 논문에서 고려하고자 하는 압력창기나 액체 저장용 탱크의 경우 유체압력 등의 내부압력에 의해 발생하는 균열은 프리 스트레스를 도입함으로써 매우 효과적으로 제어할 수 있기 때문에 상당히 유리한 구조형식이 된다. 그러니 이러한 구조물의 해석과 설계에 있어서 균열의 예측과 더불어 콘크리트의 크리이프, 건조수축 및 PC강재의 리락세이션 등과 같은 시간 의존성 변형으로 인한 프리스트래스의 손실, 여러 단계의 긴장력을 도입함으로써 발생하는 순간변형인 탄성단축 및 이로 인한 긴장력 감소 등을 정확히 계산하는 일은 매우 복잡하고 어려운 일이다. 본 논문에서는 크리이프, 건조수축 및 리락세이션 등과 같은 시간의존성 변형과 순차적으로 다단계의 프리스트레스 도입으로 인한 순간변형 및 탄성단축의 영향을 고려한 축대칭 PC 탱크 구조물의 시간에 따른 거동 및 긴장력의 변화를 유한요소법을 적용하여 해석할 수 있는 해법체계를 정리하고 이를 전산 프로그램화하여, 축대칭 PC탱크 구조물의 시간 의존성 거동에 대한 보다 정밀한 해석을 수행하였다.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.589-592
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• 2008

Recently, as importance of quality control of the structure has been recognized, non-destructive testing, determining quality of the structure without damage, has been widely applied. However, its application has been primarily focused on laboratory development because variety of parameters in field has been not fully experienced and understood. This study aims to evaluate the field applicability of the ultrasonic testing method for PC beams. Material properties of 18 cylinders, cured in the same field condition, were measured up to 60 days and compared to those of the ultrasonic measurements from 34 PC beams in field before tensioning. Test results indicate that uni-axial strength and elastic modulus of PC beams can be predicted within reasonable range using the ultrasonic technique. However, it is also noted that considerations on field condition is required to increase the reliability of estimation.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.30-35
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• 2008

The purpose of this study is to analyze and define user's emotional satisfaction factors to the PC OS GUI image. The study is to investigate the relationship between PC OS GUI Image and Sensitive Vocabula교 based on user's emotional preference. 47 user preferred sensitive words are collected by the initial survey. Through the similarity test, 47 words are narrowed down to 20 comprehend words. The semantic differential methods is used in the final survey with 5 step questionnaire. From this process, user preferred the GUI design that is vocabularized as Clear, Easy, Safety, Stability. Additionally, the result shows that the image of Clear is related to Safety and the image of Easy is related to Stability. The result of the study could be used in design PC OS GUI as base data.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.7-8
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• 2016

The use of half PC slab is increasing to shorten construction period. Because the drying shrinkage of topping concrete is restrained by PC slab, the tensile stress is generated at the topping concrete and the cracks can be occurred at the topping concrete due to drying shrinkage. Therefore, it is important to predict the tensile strain of half PC slab due to drying shrinkage to improve the quality of half PC slab. However, there is no studies on prediction of shrinkage behavior of half PC slab yet. Therefore, in this study, half PC slab was made, and the predictability of tensile strain generated at half PC slab due to drying shrinkage was investigated. The step by step method considering creep was used to estimate the tensile strain of half PC slab. In result, good agreement was obtained between the analytical and experimental values.

• Polymer(Korea)
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• v.39 no.3
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• pp.388-393
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• 2015

Low molecular weight species were extracted from PC and SAN by a solvent extraction method in order to investigate the effect of low molecular weight species on interfacial tension and affinity between PC and SAN. From the analysis of molecular weight distribution by the GPC, it was confirmed that the low molecular weight species were effectively eliminated by the solvent extraction. Interfacial tension measurements and morphological observation were carried out with the PC and SAN of which the low molecular weight species were extracted. Interfacial tension was increased and the infinity was decreased for the extracted PC and SAN pair. This result implied that the low molecular weight species play a role as a compatibilizer between two polymers. Among two polymers, low molecular weight SAN contributes more in the compatibilization. Thus, it is favorable to use SAN containing a larger amount of low molecular weight species in fabrication of PC/ABS blend.

• Journal of Korea Technology Innovation Society
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• v.8 no.1
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• pp.135-153
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• 2005

With an explosive growth of internet and a change of consumer's demand, Post PC is emerging as a substitute for the existing desktop computer and laptop computer. Post PC is a new computer which is portable with wireless networking, cheaper than the existing PCs and specialized in the specific function that consumers want. Furthermore, the shape and the ability of Post PC are dependent on its specific function. The rudimentary Post PCs such as PDA, web-pad and smart-phone are already usable. And in the future, owing to the progress of technologies, the heterogeneity of relate companies and the low entry barrier, various Post PCs will be developed. In this paper, we analyze consumers' willingness-to-pay for Post PC with the attributes such as the portability, the speed of CPU, the data input method (using key board, or notepad etc), the size of monitor and price. To estimating consumers' willingness-to-pay for the attributes of Post PC, we apply a contingent ranking method, which makes the respondents rank hypothetical Post the portability, the speed of CPU, the data input method (using key board, or notepad etc),the size of monitor and price. To estimating consumers' willingness-to-pay for the attributes of Post PC, we apply a contingent ranking method, which makes the respondents rank hypothetical Post PC alternatives featuring various combinations of attributes, to a survey data collected in Korea. Using the estimated willingness-to-pay, we predict the shape and the ability of future's Post PC and draw policy implications for the national and company level R&D strategies.