• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 춘계학술대회 논문집
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• pp.796-802
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• 2013

In this study, we investigates active control technology to reduce the noise transmitted to the outside through the opening of enclosures. A numerical model based on acoustic boundary element method is first established. Using the numerical model, the acoustic transfer functions of the field points over the opening to the primary source at arbitrary locations are estimated. The feedforward control to minimize the acoustic power through the opening is then numerically implemented. The controller generates the secondary source to destructively interfere the noise transmission through the opening. Finally, a parametric study is conducted to evaluate the effects of the location and the number of the microphones on the control performance. Furthermore, the effects of the location of the secondary source on the performance of active noise control are investigated. It is followed that the control system implemented in this study leads to a significant reduction of about 35dB in sound power through the open using only on secondary source located at the optimized position.

• 한국소음진동공학회논문집
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• 제14권2호
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• pp.164-171
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• 2004

Active control techniques have been used in wide areas of noise and nitration control engineering and a noise barrier is one of them. Omoto's work in 1993 would be one of the fundamental and systematic studies on the actively controlled noise barrier, in which he used equal number of control sources and error sensors. The error sensors were placed uniformly along the top edge of the noise barrier with equal distance apart and the control sources were placed in the exactly same way some distance apart from the error sensors. Since then, a couple of studies were made on the secondary sources'arrangement rather than the optimality of secondary source positions. Shao's results showed that arc shaped arrangement for secondary sources is better than the straight line one, and later work of Yang showed that the more important factor is the average distance between the primary source and secondary sources. However, since these studies were all executed with a simple uniform distribution of the secondary sources along the straight line or arc, it is difficult to conclude which arrangement is superior In order for the fare comparison. the optimality of the source positions in each arrangement must be given in prior. The primary goal of this study is focused on this aspect and some major factors were investigated and compared. The computer simulation results showed that the arc shaped arrangement is marginally better than the straight line one, and more importantly slightly tuned position can greatly improve the performance of the control system.

• Journal of Power Electronics
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• 제16권4호
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• pp.1621-1628
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• 2016

Experiencing power declines when the secondary coil is at the middle position between two primary coils is a serious problem in segmented on-road charging systems with a single energized segmented primary coil. In this paper, the topological transformation of a primary circuit and a hierarchical compensation capacitor control are proposed. Firstly, the corresponding compensation capacitors and receiving powers of different primary structures are deduced under the condition of a fixed frequency. Then the receiving power characteristics as a function of the position variations in systems with a single energized segmented primary coil and those with double segmented primary coils are analyzed comparatively. A topological transformation of the primary circuit and hierarchical compensation capacitor control are further introduced to solve the foregoing problem. Finally, an experimental prototype with the proposed topological transformation and hierarchical compensation capacitor control is carried out. Measured results show that the receiving power is a lot more stable in the movement of the secondary coil. It is a remarkable fact that the receiving power rises from 10.8W to 19.2W at the middle position between the two primary coils. The experimental are in agreement with the theoretical analysis.

• BMB Reports
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• 제39권2호
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• pp.178-182
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• 2006

Four strains of Acidithiobacillus ferrooxidans with different iron oxidation capacity were isolated from different mine drainage stations. The 16S rRNA gene of these strains were cloned and sequenced. Based on our sequences analysis on the four strain and the data on the other strains deposited in Genbank, all A. ferrooxidans may be classified into three phylogenetic groups. The analysis data showed that nucleotide variables (signature sites) were detected in 21 positions, and most of them were found in the first 800bp from 5' terminal except position 970 and 1375. Interestingly, the first 13 signature sites were located in two main regions:the first region (position 175-234) located in V2 while the second region (position 390-439) were detected in constant region between V2 and V3. Furthermore, the secondary structure and minimal free energy were determined in two regions among strains of three groups. These results may be useful in characterizing the microevolutionary mechanisms of species formation and monitoring in biohydrometallurgical application.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.31-33
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• 1989

In this paper, a short primary-short secondary single-sided LIM which is used as a driving source for automatic conveyor system, is selected as a analysis model. And with a method for analyzing eddy current distribution and thrust force which are produced according to the relative position of primary and secondary, FEM in which current vector potential is introduced is adopted. Also, analysis results are compared with experimental results, so propriety of this at study is proved.

• 대한전기학회논문지
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• 제39권5호
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• pp.453-461
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• 1990

In this paper, a short primary-short secondary single-sided linear induction motor which is used as the driving source for an automatic conveyor system, is selected as an analysis model. The finite element method in which the current vector potential is introduced is adopted to analyze the eddy current distribution and thrust force which are produced according to the relative position of the primary and the secondary. Also, the analysis results are compared with experimental ones, to show the propriety of this model.

• Current Optics and Photonics
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• 제3권4호
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• pp.329-335
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• 2019

Wide FOV imaging systems are important for acquiring rich visual information. A conventional catadioptric imaging system deploys a camera in front of a curved mirror to acquire a wide FOV image. This is a cumbersome setup and causes unnecessary occlusions in the acquired image. In order to reduce both the burden of the camera deployment and the occlusions in the images, this study uses a secondary planar mirror in the catadioptric imaging system. A compact design of the catadioptric imaging system and a condition for the position of the secondary planar mirror to satisfy the central imaging are presented. The image acquisition model of the catadioptric imaging system with a secondary planar mirror is discussed based on the principles of geometric optics in this study. As a backward mapping, the acquired image is restored to a distortion-free image in the experiments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.60-62
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• 1994

In this paper, the LVDT with compensating secondary coil and secondary current boost circuit is proposed. The LVDT was experiment with a test device, and analyzed with numerical method (FEM), It is shown that the LVDT has a good linearities for the measurement of the displacement and position, etc..

• 한국컴퓨터그래픽스학회논문지
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• 제18권2호
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• pp.55-62
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• 2012

본 논문에서는 GPU의 정점 셰이더에서 각 정점별 질량-스프링 모의 실험을 수행하여, 매우 빠른 속도로 피부의 2차 변형을 표현하는 새로운 방법을 제안한다. 3차원 캐릭터의 각 피부 정점에 대해, 길이가 0인 스프링으로 가상 정점을 연결하고, 캐릭터 동작에 따라서 피부 정점의 위치 및 속도가 변화하면, 질량-스프링 모의 실험을 통해 렌더링 될 가상 정점의 위치를 GPU의 정점 셰이더를 사용하여 병렬적으로 계산한다. 본 논문에서 제시하는 방법을 통해 피부의 재질 특성을 반영하는 2차 변형을 매우 빠르게 표현할 수 있으며, 각 피부 정점에 제안한 방법을 동적으로 적용하면 전통적인 2차원 애니메이션에서 관찰되는 수축-팽창(squash-and-stretch), 추종(follow-through)과 같은 효과도 매우 빠른 연산시간에 효과적으로 표현할 수 있다. 따라서 본 논문의 결과는 게임과 같은 실시간 응용분야에서 가상 캐릭터의 피부 변형을 표현하는데 효과적으로 사용될 수 있다.

• 한국통신학회논문지
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• 제37권3B호
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• pp.189-203
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• 2012

CR 네트워크에서 비인가 사용자는 인가 사용자에게 간섭 영향을 주지 않기 위해 주기적인 센싱 결과를 기반으로 유휴 채널에 기회적으로 접근한다. 하지만 비인가 송신기의 간섭 범위 내에 숨겨진 인가 수신기들이 존재할 수 있기 때문에 지역적인 센싱만으로는 인가 사용자들에 대한 완전한 보호를 보장할 수 없게 된다. 또한 유휴 채널이 존재하지 않을 경우 비인가 시스템의 지속적인 서비스 수행이 불가능해진다. 따라서 동일 채널에서의 인가시스템들을 보호함과 동시에 비인가 사용자들의 채널 이용률을 최대화하기 위해서 다양한 네트워크 시나리오를 염두에 두고 적절한 공존 방안을 도출할 필요가 있다. 본 논문에서는 uplink/downlink 스케줄과 사용자 위치 정보를 사용하여 인가 사용자에게 간섭을 주지 않는 비인가 사용자의 공존 조건을 제안한다. 비인가 기지국으로 주어진 스케줄 정보와 인가 및 비인가 사용자의 위치 정보 획득 가능 여부에 따라 네 가지 시나리오로 분류하였고, 각 시나리오 별로 인가 사용자 및 비인가 사용자의 uplink/downlink 스케줄 조합을 고려하여 공존 상황에서의 비인가 사용자의 최대 가능한 처리량을 분석하였다. 컴퓨터 모의실험 결과는 비인가 장치들의 통신 가능성을 향상시키기 위해서 제안된 방식이 실제 무선 인지 시스템에 적용될 수 있음을 다양한 상황 하에서 보여준다.