• 한국통신학회논문지
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• 제15권5호
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• pp.353-363
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• 1990

본 논문은 Data Bit Jitter(DBJ)가 Data 동기수신회로의 Bit Slip Rate(BSR) 에 미치는 영향에 관하여 고찰하였다. 특히 이 논문에서는 BSR치를 계산하는데 필요한 특성 jitter parameter 들을 부각시켰으며 또한 DBJ에 관한 새로운 규격설정을 제시하였다. 새로이 제시된 방법에 의하면 종래의 방법에 비하여 복잡해진 점은 있으나, 반면 보다 현실적이고 보다 더 정확하게 DBJ의 BSR에 관한 영향을 예측할 수 있는 장점이 있다고 생각된다. 새로이 제시된 방법에서는 수신기에 의존하는 parameter들이 부각되었으며 jitter spectrum의 각 부분(저주파, 고주파 부분등)에 대한 적절한 비중이 고려되었다.

• 융합정보논문지
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• 제9권5호
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• pp.1-6
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• 2019

모바일 시장의 확장과 함께 멀티모달 미디어 콘텐츠의 제공을 위한 플랫폼이 다양해지고 있다. 멀티모달 미디어 콘텐츠에는 이종데이터들이 복합적으로 포함되어 있어 사용자들이 선호 콘텐츠를 선택하기 위해 시간과 노력이 요구된다. 따라서 본 논문에서는 추천을 위한 키워드 가중치를 이용한 멀티모달 미디어 콘텐츠 분류를 제안한다. 제안하는 방법은 멀티모달 미디어 콘텐츠의 텍스트 데이터에서 키워드 가중치를 통해 콘텐츠를 가장 잘 나타내는 키워드를 추출한다. 추출된 키워드를 기반으로 서브클래스를 갖는 장르 클래스를 생성하고 이에 적절한 멀티모달 미디어 콘텐츠를 분류한다. 또한 개인화된 추천을 위해 사용자의 선호도 평가를 진행하여 사용자의 콘텐츠 선호도 분석 결과를 기반으로 멀티모달 콘텐츠를 추천한다. 성능평가는 추천 결과의 정확도와 만족도를 통해 우수함을 검증한다. 이는 사용자가 선호하는 장르와 키워드를 모두 고려하여 추천하기 때문에 정확도는 74.62%, 만족도는 69.1%로 높게 나타난다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1979년도 하계 전자.전기연합학술발표회논문집
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• pp.155-157
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• 1979

The Fourier convolution algorithms are used to reconstruct a 3-D density function from the projection data sets. The convolved data are then back projected to obtain a density function. There are several choices of the weighting function for the design of the reconstruction(deblurring) filter. Present paper reviews the design of reconstruction filter considering the problems such as the effects of sampling rate, aliasing, and noise.

• 전기학회논문지
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• 제68권3호
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• pp.471-479
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• 2019

This research proposes a indoor magnetic map matching algorithm that improves the position accuracy by employing multiple magnetic sensors and probabilistic candidate weighting function. Since the magnetic field is easily distorted by the surrounding environment, the distorted magnetic field can be used for position mapping, and multiple sensor configuration is useful to improve mapping accuracy. Nevertheless, the position error is likely to increase because the external magnetic disturbances have repeated pattern in indoor environment and several points have similar magnetic field distortion characteristics. Those errors cause large position error, which reduces the accuracy of the position detection. In order to solve this problem, we propose a method to reduce the error using multiple sensors and likelihood boundaries that uses human walking characteristics. Also, to reduce the maximum position error, we propose an algorithm that weights according to their importance. We performed indoor walking tests to evaluate the performance of the algorithm and analyzed the position detection error rate and maximum distance error. From the results we can confirm that the accuracy of position detection is greatly improved.

• 한국농림기상학회지
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• 제2권4호
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• pp.175-182
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• 2000

표준관측소의 점 단위 기온 관측 및 예보값을 농업분야에서 활용하기 위해서는 공간내삽이 필요한 경우가 많지만 기후학적 평년값 같은 장기간의 평균값 내삽과는 달리 지형효과를 반영하기 어려워 거리역산가중법이 수정 없이 사용되고 있다. 우리 나라처럼 지형이 복잡한 산악지역에서는 수평 거리에만 의존한 내삽 결과에 심각한 오류가 포함될 수 있으므로, 영농지원 정보로서 중요한 일 최저기온을 대상으로 추정오차의 최대근원인 해발고도의 영향을 보정 할 수 있는 간단한 공간내삽모형을 작성하였다. 먼저 남한 육지 상에 위치한 63개 표준관측소에서 수집된 일 최저기온자료와 관측소의 위치, 해안으로부터 거리, 경사향, 표고 등 국지기온 결정인자를 회귀분석 하여 표고에 따른 기온감율 추정식을 날짜의 함수로 표현하였다. 63개 관측점의 표고값을 공간내삽 하여 재구성한 전국의 가상 지형으로부터 1 km$\times$ 1 km 공간단위의 전국 수치고도값 편차를 계산하고, 여기에 해당 날짜의 기온감율을 적용하여 보정값을 계산한다. 기존의 거리역산가중법에 의한 기온추정값을 이 보정값에 의해 수정함으로써 최종 기온값을 얻는다. 임의로 선발된 1999년의 월별 하루씩 총 12일에 대하여 이 모형과 기존 거리역산가중법을 각기 적용하여 267개 자동기상관측지점의 일 최저기온을 추정한후 실측값과 비교하였다 오차평균, 절대오차평균, 그리고 평방근오차평균 등 세가지 추정오차를 분석한 결과 이 방법이 거리역산가중법에 비해 산악지역에서의 일 최저기온 추정에 있어 뚜렷한 개선효과를 보였다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2003년도 The Fifth Asian Computational Fluid Dynamics Conference
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• pp.237-239
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• 2003

The present study investigates on design optimization of rib-roughened two-dimensional channel to enhance turbulent heat transfer. Response surface method with Reynolds-averaged Navier-Stokes analysis is used as an optimization technique. Standard $k-{\varepsilon}$model with wall functions is adopted as a turbulence closure. The objective function is defined as a linear combination of heat transfer and friction drag coefficients with weighting factor. Computational results for overall heat transfer rate show good agreements with experimental data. Four design variables are optimized for weighting factor of 0.02.

• 한국정밀공학회지
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• 제33권9호
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• pp.715-721
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• 2016

In this paper, the classification rate of micro-cracks in silicon wafers was improved using a SVM. In case I, we investigated how feature data of micro-cracks and SVM parameters affect a classification rate. As a result, weighting vector and bias did not affect the classification rate, which was improved in case of high cost and sigmoid kernel function. Case II was performed using a more high quality image than that in case I. It was identified that learning data and input data had a large effect on the classification rate. Finally, images from cases I and II and another illumination system were used in case III. In spite of different condition images, good classification rates was achieved. Critical points for micro-crack classification improvement are SVM parameters, kernel function, clustered feature data, and experimental conditions. In the future, excellent results could be obtained through SVM parameter tuning and clustered feature data.

• 자동차안전학회지
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• 제3권2호
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• pp.28-33
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• 2011

This paper presents driving path estimation algorithm for adaptive cruise control system and advanced emergency braking system using multi-sensor fusion. Through data collection, yaw rate filtering based road curvature and vision sensor road curvature characteristics are analyzed. Yaw rate filtering based road curvature and vision sensor road curvature are fused into the one curvature by weighting factor which are considering characteristics of each curvature data. The proposed driving path estimation algorithm has been investigated via simulation performed on a vehicle package Carsim and Matlab/Simulink. It has been shown via simulation that the proposed driving path estimation algorithm improves primary target detection rate.

• Journal of Forest and Environmental Science
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• 제28권3호
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• pp.170-178
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• 2012

Dipterocarps or Dipterocarpaceae is a commercially important timber producing and dominant keystone tree family in the rain forests of Borneo. Borneo's landscape is changing at an unprecedented rate in recent years which affects this important biodiversity. This paper attempts to model the natural occurrence (distribution including those areas with natural forests before being converted to other land uses as opposed to current distribution) of dipterocarp species in Sarawak which is important for forest biodiversity conservation and management. Local modeling method of Inverse Distance Weighting was compared with commonly used statistical method (Binary Logistic Regression) to build the best natural distribution models for three genera (12 species) of dipterocarps. Database of species occurrence data and pseudoabsence data were constructed and divided into two halves for model building and validation. For logistic regression modeling, climatic, topographical and edaphic parameters were used. Proxy variables were used to represent the parameters which were highly (p>0.75) correlated to avoid over-fitting. The results show that Inverse Distance Weighting produced the best and consistent prediction with an average accuracy of over 80%. This study demonstrates that local interpolation method can be used for the modeling of natural distribution of dipterocarp species. The Inverse Distance Weighted was proven a better method and the possible reasons are discussed.

• 대한기계학회논문집B
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• 제28권9호
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• pp.1051-1057
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• 2004

A numerical optimization procedure for the shape of three-dimensional channel with angled ribs mounted on one of the walls to enhance turbulent heat transfer is presented. The response surface method is used as an optimization technique with Reynolds-averaged Wavier-Stokes analyses of flow and heat transfer. SST turbulence model is used as a turbulence closure. Computational results for local heat transfer rate show reasonable agreements with experimental data. The pitch-to-height ratio of the rib and rib height-to-channel height ratio are set to be 9.0 and 0.1, respectively, and width-to-rib height ratio and attack angle of the rib are chosen as design variables. The objective function is defined as a linear combination of heat-transfer and friction-loss related terms with weighting factor. Full-factorial experimental design method is used to determine the data points. Optimum shapes of the channel have been obtained in the range from 0.0 to 0.1 of weighting factor.