• 한국통계학회:학술대회논문집
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• 한국통계학회 2003년도 추계 학술발표회 논문집
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• pp.319-324
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• 2003

본 논문에서는 matched-pair design에서의 두 처리간 동등성/ 비열등성 검정에 대해 고려하였다. 기존에 비율차이나 risk ratio관점에서 동등성/비열등성 검정을 시행한 것과는 달리, 본 논문에서는 odds ratio에 기초하여 두 가지 검정통계량을 유도하였다. (1) constrained maximum likelihood estimator(mle)를 이용한 fieller type 통계량 (2) 제약없이 구한 mle를 사용한 wald-type 통계량). 비율 차이나 risk ratio에 기초한 기존의 통계적 방법들(비율차이에 근거한 (3) score-type 통계량과 (4) wald-type 통계량, risk ratio에 기초한 (5) fieller-type 통계량과 (6) wald-type 통계량)과 본 논문에서 제시한 두가지 통계량의 성능을 비교하기 위해 모의실험을 시행하였다. 모의실험 결과, 본 논문에서 제안한 constrained mle를 사용한 fieller type 통계량은 empirical type I error 측면에서 매우 만족스러운 결과를 보이고 있으며, 특히 비대각 셀의 확률이 작아질 경우에도 안정적인 성능을 보여준다.

• 전자공학회논문지A
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• 제32A권1호
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• pp.138-145
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• 1995

The offset voltage in silicon Hall plates is mainly caused by stress and strain in package, and by alignment in process. The offset voltage is appeared random for condition change with time in the factory, is non-linearly changed with temperature. In this paper proposed new method of design of Hall IC, and methematicaly proved relation layout of chip of 90$^{\circ}$-shift-current Hall plate pair is matched with "Differentail to single ended Conversion amplifier." In the experiment, the offset voltage is reduced about 1/100 time than the original offset voltage.

• 센서학회지
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• 제31권2호
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• pp.120-124
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• 2022

With advancements in underwater stealth technology for naval vessels, new sensor configurations for detecting targets have been attracting increased attention. Latest underwater mines adopt multiple sensor configurations that include electric field sensors to detect targets and to help acquire accurate ignition time. An underwater electric field sensor consists of a pair of electrodes, signal processing unit, and preamplifier. For detecting underwater electric fields, the preamplifier requires low-noise amplification at ultra-low frequency bands. In this paper, the specific requirements for low-noise preamplifiers are discussed along with the experimental results of various setups of matched transistors and chopper stabilized operational amplifiers. The results showed that noise characteristics at ultra-low frequency bands were affected significantly by the voltage noise density of the chopper amplifier and the number of matched transistors used for differential amplification. The fabricated preamplifier was operated within normal design parameters, which was verified by testing its gain, phase, and linearity.

• 한국전기전자재료학회논문지
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• 제23권9호
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• pp.667-670
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• 2010

In this paper, a high voltage current sensing circuit for boost converter is designed and verified by Cadence SPECTRE simulations. The current mirror pair, power and sensing metal-oxide semiconductor field effect transistors (MOSFETs) with size ratio of K, is used in our on-chip current sensing circuit. Very low drain voltages of the current mirror pair should be matched to give accurate current sensing, so a folded-cascode opamp with a PMOS input pair is used in our design. A high voltage high side lateral-diffused MOS transistor (LDMOST) switch is used between the current sensing circuit and power MOSFET to protect the current sensing circuit from the high output voltage. Simulation results using 0.35 ${\mu}m$ BCD process show that current sensing is accurate and the pulse frequency modulation (PFM) boost converter using the proposed current sensing circuit satisfies with the specifications.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.14-14
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• 2010

A high voltage current sensing circuit for LED driver IC is designed and verfied by Cadence SPECTRE simulations. The current mirror pair, power and sensing MOSFETs with size ratio of K, is used in our on-chip current sensing circuit. Very low drain voltages of the current mirror pair should be matched to give accurate current sensing, so a folded-cascode opamp with a PMOS input pair is used in our design. A high voltage high side LDMOST switch is used between the current sensing circuit and power MOSFET to protect the current sensing circuit from the high output voltage. Simulation results using 0.35um BCD process show that current sensing is accurate with properly frequency compensated opamp.

• 공학교육연구
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• 제25권5호
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• pp.68-74
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• 2022

The purpose of this study was to develop an infographic-based STEAM program for high school students and test its effectiveness. In this study, we converged high school 'art' education with 'Korean language' and 'mathematics.' The program was divided into four phases. The effectiveness of the program was analyzed by conducting matched pair t-test for 377 students at a girl's high school in Seoul before and after the program. The study found that the students' self-concept on mathematics and their attitude towards choosing science and engineering career showed significant increases after the program. By connecting high school courses through data visualization based on cognitive information design, findings from this study suggest that our infographic-based STEAM program should be implemented more frequently at high schools.

• 한국CDE학회논문집
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• 제9권1호
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• pp.51-61
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• 2004

Mechanical parts are often grouped into part families based on the similarity of their shapes, to support efficient manufacturing process planning and design modification. The 2-part sequence papers present similarity assessment techniques to support part family classification for machined parts. These exploit the multiple feature decompositions obtained by the feature recognition method using convex decomposition. Convex decomposition provides a hierarchical volumetric representation of a part, organized in an outside-in hierarchy. It provides local accessibility directions, which supports abstract and qualitative similarity assessment. It is converted to a Form Feature Decomposition (FFD), which represents a part using form features intrinsic to the shape of the part. This supports abstract and qualitative similarity assessment using positive feature volumes.. FFD is converted to Negative Feature Decomposition (NFD), which represents a part as a base component and negative machining features. This supports a detailed, quantitative similarity assessment technique that measures the similarity between machined parts and associated machining processes implied by two parts' NFDs. Features of the NFD are organized into branch groups to capture the NFD hierarchy and feature interrelations. Branch groups of two parts' NFDs are matched to obtain pairs, and then features within each pair of branch groups are compared, exploiting feature type, size, machining direction, and other information relevant to machining processes. This paper, the second one of the two companion papers, describes the similarity assessment method using NFD.

• 한국CDE학회논문집
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• 제9권1호
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• pp.44-50
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• 2004

Mechanical parts are often grouped into part families based on the similarity of their shapes, to support efficient manufacturing process planning and design modification. The 2-part sequence papers present similarity assessment techniques to support part family classification for machined parts. These exploit the multiple feature decompositions obtained by the feature recognition method using convex decomposition. Convex decomposition provides a hierarchical volumetric representation of a part, organized in an outside-in hierarchy. It provides local accessibility directions, which supports abstract and qualitative similarity assessment. It is converted to a Form Feature Decomposition (FFD), which represents a part using form features intrinsic to the shape of the part. This supports abstract and qualitative similarity assessment using positive feature volumes. FFD is converted to Negative Feature Decomposition (NFD), which represents a part as a base component and negative machining features. This supports a detailed, quantitative similarity assessment technique that measures the similarity between machined parts and associated machining processes implied by two parts' NFDs. Features of the NFD are organized into branch groups to capture the NFD hierarchy and feature interrelations. Branch groups of two parts' NFDs are matched to obtain pairs, and then features within each pair of branch groups are compared, exploiting feature type, size, machining direction, and other information relevant to machining processes. This paper, the first one of the two companion papers, describes the similarity assessment methods using convex decomposition and FFD.

• 대한감각통합치료학회지
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• 제10권1호
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• pp.1-10
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• 2012

목적 : 본 연구에서는 그룹감각통합치료가 감각통합장애아동의 또래 및 치료사와의 상호작용에 어떠한 영향을 미치는지 알아보고자 하였다. 연구 방법 : 연구대상은 만 3~5세의 학령전기 아동 3명으로, 실험기간은 2011년 9월에서 12월까지였다. 그룹감각통합 치료는 주1회, 회기 당 80분씩 총 15회기로 실시하였다. 또래 및 치료사와의 상호작용을 관찰하기 위해 사회적 상호작용 행동관찰 표를 사용하였다. 그룹감각통합치료 사전/사후의 상호작용 차이는 윌콕슨 순위검정(Wilcoxon matched-pair signed rank test)을 사용하여 분석하였다. 결과 : 그룹감각통합치료 프로그램을 실시하기 전보다 후에 또래 및 치료사와의 긍정적 상호작용은 증가하고 부정적 상호작용은 감소하였으나 통계적으로 유의한 차이가 없었다. 결론 : 본 연구의 결과는 그룹감각통합치료가 감각통합장애아동의 또래와 치료사와의 상호작용 향상에 긍정적인 영향을 미친다고 결론짓기에는 한계가 있다. 그러나 프로그램이 적용되는 동안 다른 아동들을 관찰하고 기존의 놀이에 참여하려는 행동이 늘어났다. 그리고 거부하기나 물건 던지기와 같은 부정적인 행동은 줄어드는 등 아동의 개별행동에는 긍정적인 변화가 있었다. 향후 연구기간, 연구대상자 선정의 고려 및 표준 데이터를 제시해 줄 수 있는 평가도구를 통해 그룹감각통합치료를 적용한다면 상호작용에 향상에 대한 명확한 결과를 볼 수 있을 것으로 기대한다.

• 대한감각통합치료학회지
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• 제7권1호
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• pp.1-12
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• 2009

목적: 본 연구는 감각통합치료를 통해 감각조절장애 아동의 놀이, 사회성, 작업수행도 및 작업만족도, 감각처리에 미치는 효과에 대하여 알아보았다. 연구방법: 연구대상은 만 4~7세의 감각조절장애 아동 5명으로, 실험기간은 2008년 6월에서 11월까지이었다. 감각통합치료는 주 2회(매50분), 총 48회기를 실시하였다. 놀이, 사회성, 작업수행도 및 만족도, 감각처리를 측정하기 위해 Revised Knox Preschool Play Scale(RKPPS), 사회성숙도 검사, Canadian Occupational Performance Measure(COPM), Japanese Sensory Inventory Revised(JSI-2)를 사용하였다. 감각통합치료의 효과를 알아보기 위해 단일집단 사전-사후 설계(one group pretest-posttest design)를 사용하였다. 감각통합치료 사전/사후의 RKPPS, 사회성숙도, COPM, JSI-2의 차이는 윌콕슨 순위검정(Wilcoxon matched-pair signed rank test)을 사용하여 분석하였다. 결과: 감각통합치료 전과 후의 RKPPS(Z=-2.023, p=.043), 사회성숙도(Z=-2.023, p=.043), 작업수행도(Z=-2.023, p=.043) 및 만족도(Z=-2.032, p=.042), 그리고 JSI-2 중 촉각계(Z=-2.032, p=.042) 점수에서 통계적으로 유의한 차이를 보였다. 결론: 본 연구는 감각통합치료가 촉각계 처리와 같은 작업수행요소뿐 아니라 놀이, 사회성과 같은 작업수행영역에도 효과가 있음을 보여주었다. 또한 감각통합 평가 및 중재 시 감각조절장애 아동의 놀이에 대해 고려해보도록 방향을 제시한 것에 의의가 있다. 그러나 연구대상자의 수가 적고, 다양한 환경적 요소에 의해 영향을 받을 수 있으므로 연구결과를 일반화하기에는 어려움이 있다. 따라서 향후 연구에서는 대상 아동의 수를 고려하고, 외적 변인을 제한하며, 타당도와 신뢰도가 높은 자료수집 방법을 사용해야 할 것으로 사료된다.