• International Journal of Advanced Culture Technology
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• 제8권3호
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• pp.307-315
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• 2020

The physique and health status of Chinese college students have received a generous concern in recent years. The physical condition of Chinese college students is not good and this phenomenon is especially obvious among female college students, which has been an disputable fact. This study starts from exercise intervention to study the concrete influence of taijiquan (a kind of traditional Chinese shadow boxing) and five-animal exercises on human body balance ability; the study uses experimental apparatus to measure the specific impact of exercise intervention on human body balance ability; meanwhile, the study also applies data analysis to longitudinally study whether the two studied sports items affect body balance, and whether there is difference in terms of the influence of two sports items on human body balance ability. The conclusions are as follows: firstly, 24-style taijiquan and five-animal exercises can improve ankle muscle strength, and the focus and degree of the improvement are different; secondly, five-animal exercises have a better improvement effect on the flexor and extensor muscles of ankle joint and 24-style taijiquan is in the second place. Moreover, compared with 24-style taijiquan, there is no significant difference in terms of the improvement caused by five-animal exercises; thirdly, 24-style taijiquan has a better effect on the improvement of internal rotation and evertors muscle strength. Compared with 24-style taijiquan, five-animal exercises have no significant difference in terms of the improvement degree.

• 한국측량학회지
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• 제34권1호
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• pp.43-52
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• 2016

기상과 시간의 제약을 받지 않고 영상을 획득할 수 있는 레이더 위성 영상은 오랫동안 홍수 탐지 분야에서 이용되어 왔다. 많은 연구들이 홍수를 효율적으로 탐지하기 위하여 다양한 기법들을 적용하였고 그 결과 홍수 지역의 탐지율은 비약적으로 상승하였다. 홍수는 침수피해를 유발하는 특성상 침수지와 비침수지의 경계 부분이 뚜렷하게 구분돼야하고 아주 세밀한 탐지가 가능해야한다. 이를 위해서는 레이더 자체의 해상도가 좋아야 할 뿐만 아니라 필터링 과정에서 해상도 저하를 최소화해야 한다. 레이더 위성의 해상도는 기술이 발전함에 따라 고해상도의 위성이 증가하고 있지만 필터링 기법을 달리하여 홍수 탐지의 정확도 및 효율성을 비교하여 홍수탐지에 적합한 필터링을 찾는 연구는 부족한 것이 현실이다. 본 연구에서는 Lee, Frost, NL-means(Non-Local means) 필터링을 위성레이더 영상에 적용하였고 필터링된 영상을 이용하여 홍수 지도를 생성한 뒤 각각의 결과를 비교하였다. Frost와 NL-means 필터는 Lee 필터에 비해 스펙클 노이즈를 저감하는데 효과적이었다. 하지만 Frost 필터의 경우에는 해상도의 저하가 심하다는 문제가 있었다. NL-means 필터는 다른 필터에 비해 shadow 현상을 효과적으로 제거하지 못하였고 이로 인해 잘못 탐지되는 픽셀이 존재한다는 문제가 있었다. 그럼에도 전체 영상의 픽셀 수에 비해 shadow 효과의 영향을 받아 오탐지되는 픽셀 수가 많지 않기 때문에 NL-means 필터를 이용한 경우가 가장 높은 홍수 탐지율을 보였다. 테스트 지역에서 필터링이 적용되지 않은 영상을 이용하여 홍수를 탐지한 경우 카파계수가 0.55로 나타났고 Lee, Frost, NL-means 필터를 적용한 경우 각각 0.64, 0.74, 0.81로 나타났다. 또한 NL-means 필터를 적용한 영상은 해상도의 변화가 거의 없는 상태에서 노이즈를 효과적으로 감소하였기 때문에 침수지와 비침수지의 경계를 가장 명확하게 구분할 수 있어 효과적으로 분석 결과를 도출하였다.

• Journal of Electrical Engineering and Technology
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• 제12권6호
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• pp.2268-2277
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• 2017

As constantly increasing wind power penetrates power grid, wind power plants (WPPs) are exerting a direct influence on the traditional power system. Most of WPPs are using variable speed constant frequency (VSCF) wind turbines equipped with doubly fed induction generators (DFIGs) due to their high efficiency over other wind turbine generators (WTGs). Therefore, the analysis of DFIG has attracted considerable attention. Precisely measuring optimum reference speed is basis of utilized maximum wind power in electric power generation. If the measurement of wind speed can be easily taken, the reference of rotation speed can be easily calculated by known system's parameters. However, considering the varying wind speed at different locations of blade, the turbulence and tower shadow also increase the difficulty of its measurement. The aim of this study is to design fuzzy controllers to replace the wind speedometer to track the optimum generator speed based on the errors of generator output power and rotation speed in varying wind speed. Besides, this paper proposes the fuzzy adaptive PID control to replace traditional PID control under rated wind speed in variable-pitch wind turbine, which can detect and analyze important aspects, such as unforeseeable conditions, parameters delay and interference in the control process, and conducts online optimal adjustment of PID parameters to fulfill the requirement of variable pitch control system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1573-1576
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• 2003

The quality of bundles is closely related with the apparent thickness. Especially the variation of apparent thickness of bundle determines the qualify of the plane structure made or the bundle such as surface evenness, pore size, and the shape of air-gap, etc.,. This study is dealing with the development of a new measuring system of the thickness of bundle or cross-section by determining the size of the shadow of the object covered by a laser slit beam. Also the measured signal is characterized in terms of the correlogram, the irregularity in wavelength. The correlogram for the irregularity of several sample types could be represented by a sinusoidal function with exponentially decaying amplitude. Moreover, influence of the measuring speed on the signal and the characteristic differences according to the different types of bundle are investigated.

• 반도체디스플레이기술학회지
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• 제11권1호
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• pp.79-83
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• 2012

We use adaptive method and determine threshold coefficient so that the algorithm could decide a suitable binarization threshold coefficient of the image to detecting a marker; therefore, we solve the light influence on the shadow area and dark region. In order to improve the speed for reducing computation we created Integral Image. The algorithm detects an outline of the image by using canny edge detection for getting damage or obscured markers as it receives the noise removed picture. The strength of the line of the outline is extracted by Hough transform and it extracts the candidate regions corresponding to the coordinates of the corners. Markers extracted using the equation of a straight edge to find the coordinates. By using the equation of straight the algorithm finds the coordinates the corners. of extracted markers. As a result, even if all corners are obscured, the algorithm can find all of them and this was proved through the experiment.

• 전기학회논문지
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• 제61권12호
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• pp.1864-1871
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• 2012

This paper proposes the hybrid proportional integral(HBPI) controller for maximum power point tracking(MPPT) control of photovoltaic system. The output characteristics of the solar cell are a nonlinear and affected by a temperature, the solar radiation and influence of a shadow. The MPPT control is a very important technique in order to increase an output and efficiency of the photovoltaic system. The conventional constant voltage(CV), perturbation and observation(PO) and incremental conductance(IC) are the method which finding maximum power point(MPP) by the continued self-excitation vibration, and uses the fixed step size. If the fixed step size is a large, the tracking speed of maximum power point is faster, but the tracking accuracy in the steady state is decreased. On the contrary, when the fixed step size is a small, the tracking accuracy is increased and the tracking speed is slower. Therefore, in order to solve these problems, this paper proposes HBPI controller that is adjusted gain of conventional PI control using fuzzy control, and the maximum power point tracks using this controller. The validity of the controller proposed in this paper proves through the results of the comparisons.

• 한국지역지리학회지
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• 제15권6호
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• pp.689-706
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• 2009

주택입지에 영향을 미치는 공간변수의 우선순위를 평가하는 과정은 일부 전문가의 경험과 직관에 의존해 온 것이 사실이다. 산간 분지에서 주택(134채)의 밀도와 태양광도 관련 공간변수의 상관성을 파악하기 위해 다중공간 회귀분석 기법이 활용되었다. 전통적인 이론에서 주택 입지를 설명하는 전형적인 변수인 고도, 경사, 도로에 대한 접근성 등은 주택밀도에 대한 영향력에서 주요 변수로서 역할을 하지 못하였다 동지의 일사량과 일조시간이 산간분지에서 주택밀도를 설명할 수 있는 결정적인 변수였다. 산간분지에서 주택 입지가 전통적인 이론에서 제시하는 고도, 경사 등 이상적인 지형특성보다는 그림자로 인한 음지를 피하는 것을 최우선 순위로 고려하는 것이 확인되었다.

• 수완나부미
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• 제11권1호
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• pp.41-70
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• 2019

As a response to Peter Jackson's call for a Southeast Asian Area Studies beyond Anglo-America, this paper argues that the achievement of this salient objective hinges on an understanding of the idea of positionality and what it entails. Drawing from reflections from Filipino scholars, positionality can be understood not merely as one's determination through geographic location or self-knowledge of one's condition within the politics of knowledge production; rather, it is the power and opportunity to claim a place from which one understands reality in one's own terms, and the capacity to effect influence within her intellectual domain. In redefining positionality as such, one realizes that crucial to establishing Southeast Asian Area studies beyond Anglo-America is acknowledging the importance of the vernacular in the production and circulation of knowledge, as well as the constant danger of English as the global lingua franca, established in the guise of an advocacy that resolves unevenness by providing equal opportunity for all intellectuals to gain "global prominence." This paper argues that, instead of trying to eradicate unevenness, one can acknowledge it as the condition of being located in a place and as a privileged position to think and create beyond the shadow of Anglo-American theory.

• 한국통신학회논문지
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• 제36권1B호
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• pp.51-59
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• 2011

본 논문은 옥내에 모바일 브로드밴드 서비스를 제공하고 음영지역을 제거하여 커버리지를 확장시킬수 있는 모바일 소행기지국 기술을 이용한 통신사업자의 와이브로 펨토셀 시법서비스 제공을 배경으로 한다. 본 논문에서는 와이브로 펨토셀 시범서비스에 대한 시범가입자의 만족도를 분석하고 이를 토대로 와이브로 펨토셀 서비스의 시장접근에 대한 전략적 시사점을 제시한다. 모바일 서비스의 만족도에 관한 기존 연구 문헌들에서 제시된 광범위한 영향 요인들을 기초로 와이브로 펨토셀 서비스의 만족도에 대한 영향 요인의 관심 범위를 시스템 품질, 서비스 품질, 요금 특성으로 한정하여 이들 요인이 미치는 영향력에 대해 분석한다. 연구 결과, 기술 및 시장에서 아직 미성숙 단계인 와이브로 펨토셀 서비스는 시스템 품질과 과금 체계가 서비스 만족도에 상당한 영향을 미치는 경향이 있는 것으로 확인됐으며 이들 요인을 우선 고려한 시장접근이 유효할 것으로 보인다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권12호
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• pp.4292-4307
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• 2021

For the research field of night infrared surveillance video, the target imaging in the video is easily affected by the light due to the characteristics of the active infrared camera and the classical ViBe algorithm has some problems for moving target extraction because of background misjudgment, noise interference, ghost shadow and so on. Therefore, an improved ViBe algorithm (I-ViBe) for moving target extraction in night infrared surveillance video is proposed in this paper. Firstly, the video frames are sampled and judged by the degree of light influence, and the video frame is divided into three situations: no light change, small light change, and severe light change. Secondly, the ViBe algorithm is extracted the moving target when there is no light change. The segmentation factor of the ViBe algorithm is adaptively changed to reduce the impact of the light on the ViBe algorithm when the light change is small. The moving target is extracted using the region growing algorithm improved by the image entropy in the differential image of the current frame and the background model when the illumination changes drastically. Based on the results of the simulation, the I-ViBe algorithm proposed has better robustness to the influence of illumination. When extracting moving targets at night the I-ViBe algorithm can make target extraction more accurate and provide more effective data for further night behavior recognition and target tracking.