• 한국전자파학회논문지
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• 제8권6호
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• pp.645-655
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• 1997

본 논문에서는 CDMA 시스댐에 적용하기 위해 기저 대역에서 설계된 비동기식 동기 추적 회로의 성능을 이론적으로 분석하고 컴퓨터 시뮬레이션을 통해 검증한다. AWGN 채널 환경에서 지터 분산을 펼스 성형 필터, 타이밍 오프셋, 신호 대 잡음 비, 루우프 필터 계수의 함수로 이론적으로 유도하고 2차 동기 추적 회로를 중심으로 루우프 필터의 설계에 판해 고찰한다. 끝으로, 설계된 동기 추적 회로를 ETRI에서 IMT-2000을 위해 설계한 동기식 CDMA 시스템의 역방향 링크에 적용하여 AWGN과 레일라이 페이딩 환경에서의 성능을 시율레이션을 통해 검증한다.

• 한국통신학회논문지
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• 제37A권12호
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• pp.1145-1151
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• 2012

본 논문에서는 binary offset carrier (BOC) 신호 추적을 위해 주변 첨두는 완벽히 제거하면서, 기존의 BOC 상관함수들보다 좁은 폭의 주 첨두를 갖는 새로운 BOC 상관함수를 제안한다. 구체적으로는 BOC 신호를 구성하는 부반송파 펄스를 펄스 구간이 더 좁은 두 개의 펄스의 합으로 해석하고, 그에 따른 부분상관함수들을 생성한다. 이후 부분상관함수들을 재조합함으로써 주변 첨두를 제거하면서도 기존 BOC 상관함수보다 상관함수의 폭이 좁은 새로운 상관함수를 생성한다. 모의실험을 통해 제안한 상관함수를 이용한 경우, 기존의 상관함수들을 이용한 경우들에 비해 더욱 향상된 신호 추적 성능을 가지는 것을 보인다.

• 한국군사과학기술학회지
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• 제11권3호
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• pp.50-57
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• 2008

A telemetry ground station has a highly directional, parabolic tracking antenna to receive a weak telemetry signal from a target at a distance. The tracking antenna with narrow beam-width normally uses the auto-track method for the target tracking. This paper presents several issues in the auto-track method and introduces a new tracking method using Self-Slaving technique. Self-Slaving means that the tracking antenna is slaved to not data measured by RADAR but GPS/INS informations received by the telemetry system for pointing. The Self-Slaving method shows good performance in comparison with auto-track method.

• 제어로봇시스템학회논문지
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• 제17권3호
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• pp.283-288
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• 2011

In this paper, an adaptive signal tracking loop for a GPS L1/L2C/L5 receiver is designed. The design parameters is adjusted according to the receiver's operating conditions such as the signal strength and the receiver dynamics by using the different characteristics of GPS L1, L2C and L5 signal. Simulation results show that the tracking accuracy of the proposed signal tracking loop is better than those of L1, L2C and L5 only signal tracking loop.

• 항공우주기술
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• 제10권1호
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• pp.45-53
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• 2011

본 연구는 직접대역확산방식(DSSS)에 대한 기술검토 자료로서 현재까지 직접대역확산방식이 적용되고 있는 통신시스템들을 알아보고 각각의 주파수, 코드길이, 확산이득, 데이터 전송속도 등의 대역확산 규격에 대하여 소개한다. 또한 발사체에 직접대역확산방식을 적용하기 위해 고려되어야 하는 사항에 대하여 알아보고 특히 도플러천이(Doppler Shift)가 직접대역확산방식의 동기획득에 미치는 영향에 대하여 기존에 연구된 사례들을 조사하고 정리하였다. 도플러천이에 대한 영향을 다루는 이유는 발사체와 같이 빠르게 이동하는 시스템에 있어서 도플러천이는 DSSS시스템의 코드추적에 주요오차요인으로 작용한다. 따라서 시스템에 적용을 위해서는 이에 대한 검토가 필요하다.

• ETRI Journal
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• 제45권3호
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• pp.462-478
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• 2023

In quantum computing, the use of Pauli frames through software traces of classical computers improves computation efficiency. In previous studies, error correction and Pauli operation tracking have been performed simultaneously using integrated Pauli frames in the physical layer. In such a complex processing structure, the number of simultaneous operations processed in the physical layer exponentially increases as the distance of the surface code encoding logical qubit increases. This study proposes a Pauli frame management architecture partitioned into two layers for a lattice surgery-based surface code and describes its structure and operation rules. To evaluate the effectiveness of our method, we generated a random circuit according to the gate ratios constituting the commonly known quantum circuits and compared the generated circuit with the existing Pauli frame and our method. Simulations show a decrease of about 5% over traditional methods. In the case of experiments that only increase the code distance of the logical qubit, it can be seen that the effect of reducing the physical operation through the logical Pauli frame becomes more important.

• Nuclear Engineering and Technology
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• 제53권7호
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• pp.2334-2340
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• 2021

Radioactive particle tracking (RPT) is a minimally invasive nuclear technique that tracks a radioactive particle inside a volume of interest by means of a mathematical location algorithm. During the past decades, many algorithms have been developed including ones based on artificial intelligence techniques. In this study, RPT technique is applied in a simulated test section that employs a simplified mixer filled with concrete, six scintillator detectors and a¹³⁷Cs radioactive particle emitting gamma rays of 662 keV. The test section was developed using MCNPX code, which is a mathematical code based on Monte Carlo simulation, and 3516 different radioactive particle positions (x,y,z) were simulated. Novelty of this paper is the use of a location algorithm based on a deep learning model, more specifically a 6-layers deep rectifier neural network (DRNN), in which hyperparameters were defined using a Bayesian optimization method. DRNN is a type of deep feedforward neural network that substitutes the usual sigmoid based activation functions, traditionally used in vanilla Multilayer Perceptron Networks, for rectified activation functions. Results show the great accuracy of the DRNN in a RPT tracking system. Root mean squared error for x, y and coordinates of the radioactive particle is, respectively, 0.03064, 0.02523 and 0.07653.

• Journal of information and communication convergence engineering
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• 제8권5호
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• pp.493-497
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• 2010

This paper address the problem of tracking multiple objects encountered in many situation in developing condensation algorithms. The difficulty lies on the fact that the implementation of condensation algorithm is not easy for the general users. We propose an automatic code generation program for condensation algorithm using MATLAB tool. It will help for general user who is not familiar with condensation algorithm to apply easily for real system. The merit of this program is that a general industrial engineer can easily simulate the designed system and confirm the its performance on the fly.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 추계학술발표회논문집(1)
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• pp.64-69
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• 1997

The code WIMS-AECL has been used for the lattice analysis of DUPIC fuel. The lattice parameters calculated by the code is sensitive to the choice of number of parameters, such as the number of tracking lines, number of condensed groups, mesh spacing in the moderator region, other parameters vital to the calculation of probabilities and burnup analysis. We have studied this sensitivity with respect to these parameters and recommend their proper values which are necessary for carrying out the lattice analysis of DUPIC fuel.

• ETRI Journal
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• 제38권4호
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• pp.767-775
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• 2016

Automatic container code recognition from a captured image is used for tracking and monitoring containers, but often fails when the code is not captured clearly. In this paper, we increase the accuracy of container code recognition using multiple views. A character-level integration method combines recognized codes from different single views to generate a new code. A decision-level integration selects the most probable results from the codes from single views and the new integrated code. The experiment confirmed that the proposed integration works successfully. The recognition from single views achieved an accuracy of around 70% for the test images collected on a working pier, whereas the proposed integration method showed an accuracy of 96%.