• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.709-712
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• 2012

In this paper, current-voltage have been considered for DGMOSFET, using the analytical model. The Possion equation is used to analytical. Threshold voltage is defined as top gate voltage when drain current is $10^{-7}A$. Investigated current-voltage characteristics of channel length changed length of channel from 20nm to 100nm. Also, The changes of current-voltage have been investigated for various channel thickness and doping concentration using this model, given that these parameters are very important in design of DGMOSFET. The deviation of conduction path and the influence of conduction path on current-voltage have been considered according to the dimensional parameters of DGMOSFET.

• Journal of Digital Convergence
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• v.14 no.10
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• pp.399-406
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• 2016

As the paradigm of science education has been changing from offering scientific knowledge to 'Public Understanding', ways of communication through visual tools in science education has become increasingly important. In this study, I considered 'Pataphor' as a visual tool for scientific communication, and suggested its functions and forms. By studying the notion of pataphor, which was used an overlapped image of virtual reality and reality in literature, in the perspective of contents design, I defined 'Pataphor' as a visual way of deducing or making the metaphysical similarity with the reality based on scientific imagination. Also, I deduced the functions of pataphor as a visual mediacy and suggested its types as "Pataphor of duplicated reality", "Pataphor of reflected reality", "Pataphor of metamorphosed reality", and "Pataphor of artificial reality". Through this study, it was found to be necessary to study in detail the ways to use pataphor depending on contents producing media's and learners' awareness process of contents so there will be a follow-up study on the ways to use pataphor.

• Tunnel and Underground Space
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• v.25 no.5
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• pp.450-461
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• 2015

Extensive numerical experiments have been carried out to investigate effect of block size and fracture geometry on hydraulic characteristics of fractured rock masses based on connected pipe flow in DFN systems. Using two fracture sets, a total of 72 2-D fracture configurations were generated with different combinations of fracture size distribution and deterministic fracture density. The directional block conductivity including the theoretical block conductivity, principal conductivity tensor and average block conductivity for each generated fracture network system were calculated using the 2-D equivalent pipe network method. There exist significant effects of block size, orientation, density and size of fractures in a fractured rock mass on its hydraulic behavior. We have been further verified that it is more difficult to reach the REV size for the fluid flow network with decreasing intersection angle of two fracture sets, fracture plane density and fracture size distribution.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.6
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• pp.1338-1342
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• 2011

In this paper, threshold voltage characteristics have been analyzed as one of short channel effects occurred in double gate(DG)MOSFET to be next-generation devices. The Gaussian function to be nearly experimental distribution has been used as carrier distribution to solve Poisson's equation, and threshold voltage has been investigated according to projected range and standard projected deviation, variables of Gaussian function. The analytical potential distribution model has been derived from Poisson's equation, and threshold voltage has been obtained from this model. Since threshold voltage has been defined as gate voltage when surface potential is twice of Fermi potential, threshold voltage has been derived from analytical model of surface potential. Those results of this potential model are compared with those of numerical simulation to verify this model. As a result, since potential model presented in this paper is good agreement with numerical model, the threshold voltage characteristics have been considered according to the doping profile of DGMOSFET.

• Journal of Biomedical Engineering Research
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• v.28 no.4
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• pp.539-548
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• 2007

In the paper, a wireless charger with the function of auto-shutdown for fully implantale middle ear hearing devices (F-IMEHD) has been designed. The wireless charger can communicate with an implant module to be turned off automatically shutdown after an internal rechargeable battery has been fully-charged by electromagnetic coupling using two coils. For the communication with an implant module, the wireless charger uses the load shift keying (LSK) method. But, the variation of the mutual inductance due to the different distance between two coils can cause the communication error in receiving the fully-charged signal from an implant module. To solve the problem, the implemented wireless charger has a variable reference generator for LSK communication. The wireless charger generates proper level of the reference voltage for a comparator using an ADC (analog-to-digital converter) and a DAC (digital-to-analog converter). Through the result of experiment, it has been confirmed that the presented wireless charger can detect signals from implantable module. And wireless charger can stop generating electromagnetic flux after an implanted battery has been fully charged in spite of variable coil distance according to different skin thickness.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.1-6
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• 2008

최근 제품이나 서비스를 기획할 때, 사용자 경험 (User Experience)의 측면에 대한 고려를 해야 한다는 이야기가 많아지고 있다. 이는 기능이나 성능을 결정할 때 기능 추가, 몇 %의 성능 상승같이 좁은 방법으로 제품이나 서비스의 기획의 방향을 결정하는 것이 아니라, 사용자가 그 기능이나 성능에서 대해서 어떻게 느끼고, 기능이나 성능을 통해서 어떤 경험을 했는지에 대한 전반적인 고려가 필요하다는 것을 여러 분야에서 공감하고 있다는 증거라 하겠다. 그러나 사용자 경험이라는 개념이 명확하게 정의되어 있지 않고, 그에 대한 실증적인 연구가 부족하여, 더 나은 사용자 경험을 제공하기 위해서 어떤 노력이 필요한지에 대해서 명확하고 쉽게 파악하기 어려운 실정이다. 기존의 HCI 분야에서는 제품이나 서비스를 평가할 때 사용성 (Usability)에 초점을 맞추어서 사용성 평가 (Usability Testing)를 통해서 정량적으로 문제점을 조사하는 방법론에 대한 연구가 많이 이루어졌다. 그러나 이러한 사용성 평가 는 사용자들의 과업 수행 시간, 과업 수행 여부 등 사용자들이 제품이나 서비스를 통해서 진행하는 결과에 대한 성능 (Performance)에 주목하고 있어서 전반적인 사용자 경험을 중요시하는 현재 HCI 가 가야 할 방향과 현업의 필요와는 부합하지 않는다고 할 수 있다. 본 논문에서는 심층 인터뷰를 통해서 사용자에게 제품 경험에 있어서 중요한 요소를 찾아내고, 각 요소를 이용하여 제품에 대한 사용자의 전반적인 경험을 설문으로 물어본 후 구조방정식 모형분석을 통하여 각 경험 요소의 가중치를 도출하였다. 또한 이러한 가중치를 바탕으로 핸드폰, MP3 플레이어, LCD TV, 냉장고의 실제 제품 평가에 적용하여 사용자 경험을 바탕으로 한 제품 평가를 진행하였다. 또한 이러한 방법론을 한국뿐만 아니라 러시아, 독일, 인도의 사용자들에게도 같은 방식으로 진행하여 실증적으로 본 연구에서 개발된 방법론이 가능한지 여부를 확인하였다.

• Journal of Sensor Science and Technology
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• v.16 no.3
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• pp.165-173
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• 2007

A differential floating mass transducer has been developed in Korea for fully implantable middle ear hearing devices (F-IMEHDs). In particular, the performance of a differential floating mass transducer (DFMT) is very important among the parts of the F-IMEHDs because the mechanical vibration generated by DFMT is delivered to the inner ear directly. In this paper, the electrical model is proposed to analyze the DFMT vibration characteristic using the mechanical model of the DFMT. The electrical model enables the simple analysis of DFMT vibration characteristics using a computer program. The proposed electrical model is simulated through PSpice as changing the values of passive elements in the electrical model. To verify the proposed model, the DFMT has been implemented on the basis of the simulated results and the experiment for vibration measurement has been carried out. Through the comparison, it is verified that the proposed model is useful to analyze the vibration characteristics of the DFMT.

• Solar Energy
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• v.16 no.2
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• pp.97-112
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• 1996

The purpose of research is to complement the circulating pump of gas boiler for the domestic and to develop a pump housing with internal three way valve: Housing and three way valve have been apart in the existing pump system. Based on the experimental result on can-typed circulating pump with existing housing, a new housing with internal three way valve was designed and manufactured. The performance of can-typed circulating pump with the new housing, and the performance of circulating pump of boiler system were tested. As a result ot the test, the new housing with internal three way valve has been excellent in respect of pump performance, weight and manufacturing cost. So It is expected to have an effect of import substitution.

• Journal of KIISE:Software and Applications
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• v.32 no.9
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• pp.888-900
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• 2005

Several researches have been proposed to formalize the knowledge preconditions problem - j.e., an action or a plan is epistemically feasible. However, since the feasibility is only checked at design-time and is assumed that it will also 1)e feasible at run-time, it is not suitable in the context of Semantic Web services composition, where many agents should share the limited resources required for the execution of Web services composition. Therefore, in this paper, we formalize a transactionally executable Web services composition which enables to guarantee its atomicity. Moreover, in order to formalize the transactional executability, we propose $TL-ALCFK_{NF}$ which extends TL-ALCF with the modal operators K and A. Based on $TL-ALCFK_{NF}$, we show how to carry out the epistemic reasoning with TL-ALCF as a language to represent Semantic Web services composition.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.508-508
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• 2015

'설계홍수량 산정요령(2012, 국토교통부)'에서 홍수량 산정시 유역면적이 $250km^2$이하의 유역을 하나의 유역으로 처리하여 홍수량을 산정하도록 제시하고 있다. 이는 소유역을 많이 분할하고 하도 홍수추적 및 합성을 통하여 홍수량을 산정할 경우 단일유역에 비해 홍수량이 과대하게 산정됨으로 이에 대한 개선방안으로 제시된 산정요령이다. 홍수량 산정 방법으로 실무에서 가장 많이 사용되고 있고 '설계홍수량 산정요령'에서 채택한 모형인 Clark 단위도법에 의한 방법으로 산정된 홍수량의 크기에 미치는 민감도가 도달시간보다 저류상수가 훨씬 크므로 합리적인 저류상수 결정방법이 매우 중요하다. 저류상수를 결정하는 방법에는 여러 가지 경험공식이 적용되고 있으며 그 중 '설계홍수량 산정 요령(2012, 국토교통부)'에서는 유역면적이나 유역형상 등을 고려하고 있는 Sabol 공식을 적용하도록 하고 있다. Sabol 공식은 유역형상계수에 의해 많은 영향을 받으며, 유역형상계수는 형상이 흐름방향으로 길쭉한지 넓적한지를 나타내는 지표로서 유역 평균폭을 본류 연장으로 나눈 값으로 정의되며, 통상 유역면적을 본류 유로연장의 제곱으로 나타낸다. 따라서 유역의 형상이 폭에 비해 길면 형상계수가 1보다 작아지며 반대로 길이에 비해 폭이 넓거나 형상이 둥글면 형상계수는 1에 근접하며, 일반적으로 우리나라 하천의 형상계수는 대부분 약 0.5~0.1 정도의 범위를 나타내고 있다. 그러나, Sabol공식을 적용하여 저류상수를 산정할 경우 유역형상계수가 극히 작을 경우 홍수량이 과소하게 산정되므로 적절한 유역분할을 통해 홍수량을 보정할 필요가 있다. 따라서, 미호천 권역에서 유역형상계수가 0.1 이하인 유역을 대상으로 단일유역으로 산정한 홍수량과 적절한 유역 분할 후 홍수량을 산정하여 비교하고 비슷한 규모의 인근유역의 홍수량과 기산정된 홍수량을 비교하여 유역형상계수 0.1이하에서의 적절한 소유역 분할 기준을 제시하여 홍수량이 과대 및 과소하게 산정되지 않도록 조정하는데 있다.