• Journal of Power Electronics
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• 제5권3호
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• pp.173-179
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• 2005

In this paper, a very low cost and robust sensing method for the rotor position of a TSRM(Toroidal Switched Reluctance Motors) is described. Position information of the rotor is essential for SRM drives. The rotor position sensor such as an opto-interrupter or high performance encoder is generally used for the estimation of rotor position. However, these discrete position sensors not only add complexity and cost to the system but also tend to reduce the reliability of the drive system. In order to solve these problems, in the proposed method, rotor position detection is achieved using voltage waveforms induced by the time varying flux linkage in the search coils, and then the appropriate phases are excited to drive the SRM. But the search coil's EMF is generated only when the motor rotates. Therefore the rotor position sensing method using squared Euclidean distance at a standstill is also examined. The simulation and experimental results are presented to verify the performance of the proposed method in this paper.

• 한국통신학회논문지
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• 제41권9호
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• pp.1057-1059
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• 2016

무선 센서 네트워크에서 센싱 정보의 수집 시간과 노드의 에너지 소비량 간의 트레이드오프를 고려하여 에너지 소비를 최소화하면서도 빠른 시간 내에 센싱 정보를 수집하는 에너지 효율적인 데이터 병합 트리의 생성 방법을 제안한다. 본 제안 방안은 빠른 정보 수집을 위하여 센서노드와 싱크노드간 최대 거리의 증가를 최소화하면서 에너지 소비를 줄이기 위하여 노드간 연결 링크 비용을 최소화하는 병합 트리를 생성한다. 시뮬레이션 결과, 제안 방법은 기존 방법 보다 병합 트리를 보다 더 낮은 복잡도로 생성 가능하며 기존 방식 대비 높은 에너지 효율을 보여 준다.

• 한국산학기술학회논문지
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• 제8권5호
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• pp.1135-1140
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• 2007

본 논문은 자연영상에서 문자의 크기와 방향에 무관한 적응적 문자-에지 맵을 이용한 에지-기반 텍스트 영역검출 알고리즘을 제안한다. 첫 번째로, 에지 이미지로부터 에지 레이블을 얻고, 레이블 이미지로부터 문자를 찾기 위해 배열문법을 이용하여 적응적 문자-에지 맵을 적용한다. 선택된 레이블은 이웃 레이블과의 거리를 기준으로 클러스터 된다. 그 결과 텍스트 후보 영역이 얻어진다. 최종적으로, 텍스트 후보 영역은 경험적 규칙과 텍스트 영역에 대한 수평/수직 프로파일을 분석함으로서 검증된다. 실험결과 제안한 알고리즘은 다양한 문자의 크기 변화, 문자열의 방향, 그리고 복잡한 배경에서도 강인한 텍스트 영역 검출 결과를 보였다.

• 전기학회논문지
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• 제61권1호
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• pp.135-142
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• 2012

In this paper, we proposed a new architecture called radial basis function-based polynomial neural networks classifier that consists of heterogeneous neural networks such as radial basis function neural networks and polynomial neural networks. The underlying architecture of the proposed model equals to polynomial neural networks(PNNs) while polynomial neurons in PNNs are composed of Fuzzy-c means-based radial basis function neural networks(FCM-based RBFNNs) instead of the conventional polynomial function. We consider PNNs to find the optimal local models and use RBFNNs to cover the high dimensionality problems. Also, in the hidden layer of RBFNNs, FCM algorithm is used to produce some clusters based on the similarity of given dataset. The proposed model depends on some parameters such as the number of input variables in PNNs, the number of clusters and fuzzification coefficient in FCM and polynomial type in RBFNNs. A multiobjective particle swarm optimization using crowding distance (MoPSO-CD) is exploited in order to carry out both structural and parametric optimization of the proposed networks. MoPSO is introduced for not only the performance of model but also complexity and interpretability. The usefulness of the proposed model as a classifier is evaluated with the aid of some benchmark datasets such as iris and liver.

• 한국멀티미디어학회논문지
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• 제5권4호
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• pp.386-392
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• 2002

본 논문에서는 유리 B 스플라인 곡선을 이용한 새로운 블록 효과 감소 방법을 제안한다. 블록 효과는 매우 낮은 비트율로 블록 기반 부호화 방식을 수행할 때 복원 영상에서 나타나는 블록 형태의 왜곡을 의미한 다 제안된 기법에서는 컴퓨터 그래픽스 분야에서 제어점을 근사하는 부드러운 곡선을 생성하기 위해 사용되는 유리 B 스플라인 곡선을 이용하여 블록 효과를 감소시킨다 즉 블록 경계 영역의 화소들을 제어점으로 사용하며, 처리될 화소와 블록 경계간의 거리에 따라 가중치를 차등적으로 설정함으로써 블록 효과가 효율적으로 감소되도록 한다. 모의 실험은 제안된 방법이 기존 방법들에 비해 우수한 블록효과 감소 성능을 가지는 것을 나타낸다.

• 한국발생생물학회지:발생과생식
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• 제24권4호
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• pp.327-335
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• 2020

Genomic DNA (gDNA) extracted from two populations of natural and cultured river pufferfish (Takifugu obscurus) was amplified by polymerase chain reaction (PCR). The complexity of the fragments derived from the two locations varied dramatically. The genetic distances (GDs) between individuals numbered 15 and 12 in the cultured population was 0.053, which was the lowest acknowledged. The oligonucleotide primer OPC-11 identified 88 unique loci shared within each population reflecting the natural population. The OPC-05 primer identified 44 loci shared by the two populations. The average band-sharing (BS) values of individuals in the natural population (0.683±0.014) were lower than in those derived from the cultured population (0.759±0.009) (p<0.05). The shortest GD demonstrating a significant molecular difference was found between the cultured individuals # 15 and # 12 (GD=0.053). Individual # 02 of the natural population was most distantly related to cultured individual # 22 (GD=0.827). A cluster tree was built using the unweighted pair group method with arithmetic mean (UPGMA) Euclidean GD analysis based on a total of 578 various fragments derived from five primers in the two populations. Obvious markers identified in this study represent the genetic structure, species security, and proliferation of river pufferfish in the rivers of the Korean peninsula.

• 시스템엔지니어링학술지
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• 제17권2호
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• pp.129-138
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• 2021

Today, as the number of vehicles equipped with autonomous driving functions increases, the use of various sensors increases, and the complexity of system configuration increases. The ISO 26262 standard was published to prevent caused by systematic errors. Recently, the issue of external environmental factors rather than mechanical failure has increased. This issue is a problem outside of the scope of ISO 26262, and the ISO/DIS 21448 standard was published to solve this problem. Also, Mobileye proposed the RSS model that defined safe distance for dangerous situations in order to secure the safety of autonomous vehicles and who is responsible in case of an accident. In this paper, integrated process of ISO 21448 and RSS model, and through these results, we expect that possible to contribute to securing the safety and reliability of autonomous vehicles in the future.

• 대한임베디드공학회논문지
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• 제18권2호
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• pp.75-80
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• 2023

Unmanned drone stations for automatic charging have been developed in order to overcome the flying time limitation of rotary wing drones. Since the drone stations is an unmanned operating system, each of the drones will be required to have a high degree of landing accuracy. Drone precision landing has been mainly studied depended on image processing technologies, but the image processing systems make several problems, such as the mission weight, the drone cost, and the development complexity increases, and the flight time decrease. Thus, this paper researched accuracy of precision landing based on RTK (real time kinetics) for rotary wing drones. For the experiments of RTK based precision landing, a drone repeatedly performed three missions. The survey accuracies of the RTK about missions respectively were set as 0.3, 0.2, and 0.1 meters. Each mission has one take-off point, two way-points and one landing-point, and was repeated ten times. The experiment results revealed landing error distance means of around 0.258, 0.12 and 0.057 meters on each of RTK setting.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.776-783
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• 2022

Since Mechanical, Electrical, and Plumbing(MEP) routing is a repetitive and experience-centered process that requires considerable time and human resources, if automated, design errors can be prevented and the previously required time and human resources can be reduced. Although research on automatic routing has been conducted in many industries, the MEP routing in AEC projects has yet to be identified due to the complexity of system configuration, distributed expertise, and various constraints. Therefore, the purpose of this study is to identify the target subjects for MEP routing automation and the constraints of each subject. The MEP design checklist provided by a CM company and existing literature review were conducted, and target subjects and constraints were identified through process observation and in-depth expert interviews for five days by visiting a MEP design company. The target subjects were largely divided into six categories: air conditioning plumbing, air conditioning duct, restroom sanitary plumbing, heating plumbing, and diagram. The findings from interviews show that work reduction and error reduction has the greatest effect on air conditioning plumbing while the level of difficulty is the highest in air conditioning duct and restroom sanitary plumbing. Major constraints for each subject include preventing cold drafts on air conditioning pipes, deviation in ventilation volume in air conditioning ducts, routing order on restroom sanitary plumbing, and separation distance from the wall on heating plumbing. In this way, subjects and constraints identified in this study can be used for MEP automatic routing.

• 한국정보통신학회논문지
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• 제8권1호
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• pp.123-136
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• 2004

본 논문에서는 $GF({2^n})$상 곱셈의 복잡도와 규칙도를 GF(2)상의 다항식 곱셈을 표현하는 행렬식의 행과 열의 해밍 가중치를 이용하여 정의한다 차분공격에 강한 블록 암호 알고리즘을 만들기 위해서는 치환계층과 확산계층의 $GF({2^n})$상 곱셈의 복잡도와 규칙도가 높아야함을 실험을 통하여 보인다. 실험 결과를 활용하여 우리나라 표준인 128 비트 블록 암호 알고리즘인 SEED의 S 박스와 G 함수를 구성하는 방식을 제안한다. S 박스는 비 선형함수와 아핀변환으로 구성한다. 비 선형함수는 차분공격과 선형공격에 강한 특성을 가지며, '0'과 '1'을 제외하고 입력과 출력이 같은 고정점과 출력이 입력의 1의 보수가 되는 역고정점을 가지지 않는 $GF({2^8})$ 상의 역수로 구성한다. 아핀변환은 입력과 출력간의 상관을 최저로 하면서 고정점과 역고정점이 없도록 구성한다. G 함수는 4개의 S 박스 출력을 $GF({2^8}) 상의 4 {\times} 4$ 행렬식을 사용하여 선형변환한다. 선형변환 행렬식 성분은 높은 복잡도와 규칙도를 가지도록 구성한다 또한 MDS(Maximum Distance Separable) 코드를 생성하고, SAC(Strict Avalanche Criterion)를 만족하고, 고정점과 역고정점 및 출력이 입력의 2의 보수가 되는 약한 입력이 없도록 G 함수를 구성한다. 비선형함수와 아핀변환 및 G 함수의 원시다항식은 각기 다른 것을 사용한다. 본 논문에서 제안한 S 박스와 G 함수는 차분공격과 선형공격에 강하고, 약한 입력이 없으며, 확산 특성이 우수하므로 안전성이 높은 암호 방식의 구성 요소로 활용할 수 있다.