• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.869-872
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• 2006

본 연구에서는 나노구조 이중게이트 FinFET에 대하여 문턱전압이동 특성을 분석하였다. 분석을 위하여 분석학적 전류모델을 개발하였으며 열방사 전류 및 터널링 전류를 포함하였다. 열방사전류는 포아슨방정식에 의하여 구한 포텐셜분포 및 맥스월-볼쯔만통계를 이용한 캐리어분포를 이용하여 구하였으며 터널링전류는 WKB(Wentzel-framers-Brillouin)근사를 이용하였다. 이 두 모델은 상호 독립적이므로 각각 전류를 구해 더함으로써 문턱전압을 구하였다. 본 연구에서 제시한 모델을 이용하여 구한 문턱전압이동값이 이차원시뮬레이션값과 비교되었으며 잘 일치함을 알 수 있었다. 분석 결과 10nm이하에서 특히 터널링의 영향이 증가하여 문턱전압이동이 매우 현저하게 나타남을 알 수 있었다. 이러한 단채널현상을 감소시키기 위하여 채널두께 및 게이트산화막의 두께를 가능한한 얇게 제작하여야함을 알았으며 이를 위한 산화공정개발이 중요하다고 사료된다.

• 한국정보통신학회논문지
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• 제11권4호
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• pp.760-765
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• 2007

본 연구에서는 나노구조 이중게이트 FinFET에 대하여 문턱전압이동 특성 및 드레인유기장벽저하(Drain Induced Barrier Lowering; DIBL)특성을 분석하였다. 분석을 위하여 분석학적 전류모델을 개발하였으며 열방사전류 및 터널링전류를 포함하였다. 열방사전류는 포아슨방정식에 의하여 구한 포텐셜분포 및 맥스월-볼쯔만통계를 이용한 캐리어분포를 이용하여 구하였으며 터널링 전류는 WKB(Wentzel-Kramers-Brillouin)근사를 이용하였다. 이 두 모델은 상호 독립적이므로 각각 전류를 구해 더함으로써 문턱 전압을 구하였다. 본 연구에서 제시한 모델을 이용하여 구한 문턱 전압 이동값이 이차원 시뮬레이션값과 비교되었으며 잘 일치함을 알 수 있었다. 분석 결과 10nm 이하에서 특히 터널링의 영향이 증가하여 문턱전압이동 및 DIBL이 매우 현저하게 나타남을 알 수 있었다. 이러한 단채널현상을 감소시키기 위하여 채널두께 및 게이트산화막의 두께를 가능한한 얇게 제작하여야함을 알았으며 이를 위한 산화공정개발이 중요하다고 사료된다.

• The Korean Journal of Pain
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• 제33권2호
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• pp.121-130
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• 2020

Background: Transcutaneous electrical nerve stimulation (TENS), manual acupuncture (MA), and spinal cord stimulation (SCS) are used to treat a variety of pain conditions. These non-pharmacological treatments are often thought to work through similar mechanisms, and thus should have similar effects for different types of pain. However, it is unclear if each of these treatments work equally well on each type of pain condition. The purpose of this study was to compared the effects of TENS, MA, and SCS on neuropathic, inflammatory, and non-inflammatory pain models. Methods: TENS 60 Hz, 200 ㎲, 90% motor threshold (MT), SCS was applied at 60 Hz, an intensity of 90% MT, and a 0.25 ms pulse width. MA was performed by inserting a stainless-steel needle to a depth of about 4-5 mm at the Sanyinjiao (SP6) and Zusanli (ST36) acupoints on a spared nerve injury (SNI), knee joint inflammation (3% carrageenan), and non-inflammatory muscle pain (intramuscular pH 4.0 injections) in rats. Mechanical withdrawal thresholds of the paw, muscle, and/or joint were assessed before and after induction of the pain model, and daily before and after treatment. Results: The reduced withdrawal thresholds were significantly reversed by application of either TENS or SCS (P < 0.05). MA, on the other hand, increased the withdrawal threshold in animals with SNI and joint inflammation, but not chronic muscle pain. Conclusions: TENS and SCS produce similar effects in neuropathic, inflammatory and non-inflammatory muscle pain models while MA is only effective in inflammatory and neuropathic pain models.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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• pp.63-68
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• 1998

This paper proposes fuzzy regression analysis with non-symmetric fuzzy coefficients. By assuming non-symmetric triangular fuzzy coefficients and applying the quadratic programming fomulation, the center of the obtained fuzzy regression model attains more central tendency compared to the one with symmetric triangular fuzzy coefficients. For a data set composed of crisp inputs-fuzzy outputs, two approximation models called an upper approximation model and a lower approximation model are considered as the regression models. Thus, we also propose an integrated quadratic programming problem by which the upper approximation model always includes the lower approximation model at any threshold level under the assumption of the same centers in the two approximation models. Sensitivities of Weight coefficients in the proposed quadratic programming approaches are investigated through real data.

• International Journal of Air-Conditioning and Refrigeration
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• 제16권2호
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• pp.51-63
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• 2008

A study of literatures on flow boiling heat transfer and two-phase flows inside microchannels is summarized. The potential applications, fabrication method and efforts to determine certain dimensional threshold for microchannels classifications are discussed. For the last two decades, numerous two-phase flow and heat transfer models for microchannels have been developed; many of them were derived from empirical models originally applied for conventional channels. Those models are discussed here along with a brief review on recent development of theoretical and phenomenological-based models for microchannels. This study is devoted to provide a review of important issues on flow boiling heat transfer and two-phase flows inside microchannels, including two-phase flow patterns, boiling heat transfer mechanism and correlations developments, pressure drop and prediction methods, and critical heat flux.

• 한국음향학회지
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• 제23권1호
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• pp.82-89
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• 2004

고음질 합성을 하면서도 다양한 음색을 갖도록 하기 위해서는 파형부호화를 이용한 합성법에 적용할 수 있는 피치 변경법이 필요하다. 따라서 본 논문에서는 스펙트럼 왜곡률을 최소화하는 영교차 단위의 시간축 조절에 의한 피치 변경법과 피치 동기분석이 용이하고 다른 영역으로의 변환과정이 불필요한 피치시점 검출법을 제안함으로써 고음질을 유지하면서 시간영역에서만 처리됨으로써 계산량을 줄이고 스펙트럼 왜곡률을 최소화하고 위상을 그대로 보존할 수 있는 시간영역에서의 피치 변경법을 제안하였다. 결과적으로 전체 피치 변경율에 대해서는 기존의 방법에 비해서 제안한 방법의 스펙트럼 왜곡률이 0.73%개선되었고 피치 압축시에는 제안한 방법의 스펙트럼 왜곡율이 2.18%개선되었다.

• 대한토목학회논문집
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• 제12권1호
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• pp.115-122
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• 1992

실시간 유출예측에서 주로 쓰이는 추계학적 강우-유출 과정모형은 모형구조가 간단하고 상태 공간 모형으로 수식화하기에 용이한 TF모형이다. 이 모형을 이용하여 실시간 유출예측을 효율적으로 수행하기 위해서는 정확한 모형구조의 결정이 선행되어야 하며, 특히 예측초기의 오차를 줄일 수 있는 방법이 요구된다. 본 연구에서는 이를 위하여 유역의 초기습윤상태를 나타낼 수 있는 5일 선행강우지수를 threshold개념으로 도입하고, 각각의 TF모형을 Box-Jenkins 방법으로 등정하여 비교 검토하여 보았다.

• 원예과학기술지
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• 제30권5호
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• pp.596-602
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• 2012

Infestations of Aphis gossypii per leaf in greenhouse cultivation of cucumbers were investigated to develop binomial sampling plans. An empirical $P_T-m$ model, $ln(m)={\alpha}+{\beta}ln[-ln(1-P_T)]$, was used to evaluate relationship between the proportion of infested leaves with ${\leq}$ T aphids per leaf ($P_T$) and mean aphid density (m). Tally thresholds (T) were set to 1, 3, 5, 7, and 9 aphids per leaf to find appropriate T in greenhouse cultivation of cucumbers. Increasing sample size had little effect on the precision of the binomial sampling plan. However, the precision increased with tally threshold. The binomial model with T = 5 provided appropriate predictions of the mean densities of A. gossypii in the greenhouse cultivation of cucumbers. Using a binomial model with T = 5 (sample size = 200), a wide range of densities (1.2 - 222.8 aphids per leaf) could be estimated with precision levels of 0.346 - 0.380 for $P_T$ values between 0.15 and 0.96. Binomial models were validated at T = 5 and 7 using 12 independent data sets. Both binomial models were robust and adequately described aphid densities; most of the independent sampling data fell within 95% confidence intervals around the prediction model.

• 지역연구
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• 제15권1호
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• pp.63-73
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• 1999

It is generally believed that there is a trade-off between economic growth and environmental quality since pollutants are generated in the process of production and consumption of commodities. Several researchers have shown this prevailing belief using the short-term input-output models. The literature, however, shows that there have been few attempts to investigate the relationship using long-term forecasting models. This motivates the current paper. This paper attempts to build a reginal growth model in a partial equilibrium framework taking into consideration the requirements of capital invested for pollutant abatement. Model is largely neoclassical. Labor is assumed to move a region with high utility specified in regional per capita average was income and pollution level while capital is partially mobile to a region with high returns. The regional growth is explored in a phase diagram. The paper shows that there are two stable growth equilibria which a region can converge over time and that the equilibria are distinguished by the initial threshold capital stock that a region holds. If the initial capital stock of a region is over(under) than the threshold size, the region converges to the higher (lower) growth equilibrium over time. Moreover, based on this result an environmental quality enhancing policy is analyzed in the phase diagram. It has revealed that the policy calls for the relocation of growth equilibrium points, specifically speaking, it stimulates an increase in labor stock and a decrease in capital stock. Hence the paper has suggested that the prevailing belief which the environmental policy negatively impacts on a regional economic growth is not always true.

• 한국멀티미디어학회논문지
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• 제25권6호
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• pp.886-893
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• 2022

Outlier detection refers to the task of detecting data that deviate significantly from the normal data distribution. Most outlier detection methods compute an outlier score which indicates the degree to which a data sample deviates from normal. However, setting a threshold for an outlier score to determine if a data sample is outlier or normal is not trivial. In this paper, we propose a binary prediction method for outlier detection based on spectral clustering and one-class SVM ensemble. Given training data consisting of normal data samples, a clustering method is performed to find clusters in the training data, and the ensemble of one-class SVM models trained on each cluster finds the boundaries of the normal data. We show how to obtain a threshold for transforming outlier scores computed from the ensemble of one-class SVM models into binary predictive values. Experimental results with high dimensional text data show that the proposed method can be effectively applied to high dimensional data, especially when the normal training data consists of different shapes and densities of clusters.