• Aerospace Engineering and Technology
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• 제1권1호
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• pp.28-41
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• 2002

The purpose of this paper is to show and define the performance, the system mechanization and the algorithm of the Strapdown Inertial Navigation System(SDINS). First, navigation equations are derived in the Earth Fixed mechanization and this mechanization apply to the two kinds of inertial measurement units which consist of same fiber optic gyros and different accelerometers(SDINS-1 and SDINS-2). Those two accelerometers have the different bias. To evaluate its performance, two kinds of tests have been performed - static motionless test, and rectangle-route moving test. The results of the moving test are compared with the results of Differential GPS which has an accuracy with ±2.0mm. and are presented in this paper.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제38A권4호
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• pp.318-324
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• 2013

For blind channel equalization, the reliability of signal estimate determines the convergence speed and steady-state performance of the equalizer. Therefore the nonlinear estimator and reference signal being used in signal estimate should be chosen appropriately. In this paper, to increase the reliability of the signal estimate, two errors were obtained by applying coarse signal points and dense signal points respectively to signal estimate, the relative reliabilities of two errors were calculated, then the equalizer was adapted deferentially utilizing the reliabilities. At this point, by applying two errors alternately, two modes of operation were smoothly combined. Through computer simulations the proposed method was confirmed to achieve fast transient state convergence and low steady-state error compared to traditional methods.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국해양정보통신학회 2005년도 춘계종합학술대회
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• pp.206-209
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• 2005

Optimal path search systems to take continuously changed traffic flows into consideration is necessary in order to reduce the cost to get destination. However, to search optimal path in client terminals with low computing power yields high computational cost. Thus, a method with low cost and near optimal path as well is required. In this paper, we propose a path search method using variable heuristic for the sake of reducing operation time. The heuristic is determined by the change of the average speeds of cars located in grid which means a rectangle region.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국해양정보통신학회 2005년도 춘계종합학술대회
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• pp.462-466
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• 2005

Dynamic (On-line) signature verification system consists of preprocessing, feature extraction, comparison and decision process for internal processing, and registration and verification windows for the user interface. We describe an implementation and design for an advanced dynamic signature verification system. Also, we suggest the method of feature extraction, matching algorithm, efficient user interface and an objective criteria for evaluating the performance.

• The KIPS Transactions:PartB
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• 제15B권3호
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• pp.253-258
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• 2008

Recently, game players want new game requiring more various tactics and strategies in the complex environment beyond simple and repetitive play. Various artificial intelligence techniques have been suggested to make the game characters learn within this environment, and the recent researches include the neural network and the genetic algorithm. The Genetic programming(GP) has been used in this study for learning strategy of the agent in the pursuit-evasion problem which is used widely in the game theories. The suggested GP algorithm is faster than the existing algorithm such as neural network, it can be understood instinctively, and it has high adaptability since the evolving chromosomes can be transformed to the reasoning rules.

• Journal of IKEEE
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• 제25권4호
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• pp.584-590
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• 2021

This paper proposes a removal method of signal interference between ultrasound sensors where ghost signals due to interference are excluded and correct signal is recognized in distance mensurement using ultrasound sensors. The proposed method detects and excludes ghost signals when previous measured distance is compared to current measured distance and the distance difference exceeds a threshold. The threshold is fixed in conventional methods, so ghost signals cannot be correctly excluded when ultrasound sensor or target object move rapidly. On the contrary, to improve accuracy, the threshold is not fixed in the proposed method, and the threshold is adpatively determined based on the relative velocity when ultrasound sensor or target object move. Experiments of distance measurement with ultrasound signal interference are carried out where multiple ultrasound sensors of same type are exploited with maximum interference, and the results show that the proposed method efficiently exclude ghost signals.

• Proceedings of the Korea Information Processing Society Conference
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• 한국정보처리학회 2024년도 춘계학술발표대회
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• pp.851-853
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• 2024

본 논문에서는 MediaPipe 라이브러리 및 OpenCV 를 활용한 포즈 추정 및 체형 인식 알고리즘을 통해 사용자의 체형과 선호도에 맞는 의류를 가상으로 입어볼 수 있는 생성형 FashionNet 을 제안한다. 구체적으로는 먼저 웹 카메라를 통해 얻어진 사용자의 외형 이미지로부터, 사용자의 신체 포즈를 추정하고, OpenCV 코드를 통해 사용자의 신체 윤곽을 검출한다. 이후 가상 옷장 데이터베이스로부터 선택된 가상 의류를 사용자의 신체 윤곽에 맞춰 입혀진 가상 피팅 이미지를 생성한다. 특히, 본 논문의 FashionNet 은 사용자와 카메라 간의 거리에 따른 인체 비율을 사전 실험으로 미리 설정해놓음으로써, 카메라와 사용자간의 거리에 관계없이 의류 사이즈가 사용자의 신체 조건에 맞게 자동으로 피팅되는 특징을 갖는다. 또한 가상 옷장 데이터베이스로부터 의류 아이템 선정의 편의를 제공하기 위해, 가상 현실 속에서 스크린상의 메뉴 버튼과 사용자의 포즈 동작간의 상호작용을 통해 FashionNet 의 다양한 기능을 수행할 수 있는 증강현실(AR) 기법을 적용하였다. 가상 옷장 데이터베이스를 사용한 다양한 가상 피팅 체험 실험을 통해 온라인상에서 자기가 원하는 의류를 가상으로 착용해 볼 수 있고 이를 통해 구매를 결정하는 등의 FashionNet 의 유효성과 가능성을 확인하였다.

• Journal of KIISE:Information Networking
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• 제32권4호
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• pp.471-482
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• 2005

The high-speed network permits Grid computing to handle large problem of management areas and share various computational resources. As there are many resources and changes of them in Grid computing, the resources should be detected effectively and matched correctly with tasks to provide high performance. In this paper, we propose a mechanism that maximizes the performance of Grid computing systems. According to a priority, grade and site of heterogeneous resources, we assign tasks to those resources. Initially, a volunteer's priority and ranking are determined by static information like as CPU speed, RAM size, storage size and network bandwidth. And then, the rank of resources is decided by considering dynamic information such as correctness, response time, and error rate. We find that overall Grid system performance is improved and high correctness using resource reallocation mechanism is achieved.

• Journal of the Institute of Electronics Engineers of Korea SD
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• 제41권1호
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• pp.81-90
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• 2004

The state assignment for a finite state machine greatly affects the delay, area, power dissipation, and testabilities of the sequential circuits. In order to improve the testabilities and power consumption, a new state assignment technique . based on m-block partition is introduced in this paper. By the m-block partition algorithm, the dependencies among groups of state variables are minimized and switching activity is further reduced by assigning the codes of the states in the same group considering the state transition probability among the states. In the sequel the length and number of feedback cycles are reduced with minimal switching activity on state variables. It is inherently contradictory problem to optimize the testability and power consumption simultaneously, however our new state assignment technique is able to achieve high fault coverage with less number of scan nfp flops by reducing the number of feedback cycles while the power consumption is kept low upon the low switching activities among state variables. Experiment shows drastic improvement in testabilities and power dissipation for benchmark circuits.

• The Journal of Engineering Geology
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• 제24권3호
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• pp.343-351
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• 2014

Tunnel face mapping plays an important role in risk analysis and infrastructure support decisions during tunnel construction. In this study, a digital mapping system using a mobile device is employed instead of existing face-mapping methods that rely upon face mapping sheets. The mobile device is then connected to the main server in the field, where a tunnel-specific database is compiled automatically. This information provides real-time feedback on the tunnel face to construction personnel and engineers, thus allowing for rapid assessment of tunnel face stability and infrastructure needs. The Douglas-Peucker algorithm, among others, is employed to resolve problems arising from the detailed mapping and speed problem by data accumulation. This system is expected to raise program optimization through field verification and additional functional improvements.