• Journal of Advanced Marine Engineering and Technology
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• 제29권1호
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• pp.124-131
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• 2005

This paper suggests LOS(Line-Of-Sight) guidance system of a surface vessel in straight-line navigation under ocean currents An LOS vector from the vessel to a point on the path between two way-points is decided and a heading angle is calculated to converge to follow the desired path based on the LOS vector This guidance system is called LOS guidance system. The suggested LOS guidance law has parameters to be properly chosen according to navigational environment. Parameters of LOS guidance system are optimized to reduce propulsive energy and/or position error between desired Position and present position of a ship using genetic algorithm which is a strong optimization algorithm with adaptational random search The effectiveness of the suggested LOS guidance system is assured through computer simulations.

• 한국도로학회논문집
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• 제17권2호
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• pp.123-134
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• 2015

PURPOSES : The key point of a multimodal LOS (level-of-service) evaluation system is that all of the modes are mutually associated to determine each mode's LOS. For example, the LOS of the bicycle mode is measured based on not only bicycle volumes, but also automobile volumes. However, the Korea Highway Capacity Manual (KHCM) still focuses on the automobile mode in evaluating the LOS of the roads. Additionally, the KHCM's LOS of the other modes, except for the automobile, is not consistent with actual road conditions. The KHCM, therefore, needs to develop and introduce a multimodal LOS system in order to evaluate the service conditions more accurately. METHODS: As a preliminary step to the introduction of multimodal LOS research, in this study the current problem of the KHCM's LOS system through a close review and comparison with other HCMs (highway capacity manuals) was identified. Secondly, a field survey and investigation of the urban streets to apply the HCM's multimodal LOS system was conducted. Finally, a comparison analysis of the results of the HCM and KHCM LOS was performed. RESULTS: In the study, it was found that the results of the LOS for the automobile mode did not show a significant difference between the HCM and KHCM. However, the LOS of the bicycle and pedestrian mode tended to be worse in the multimodal LOS system, which results from considering the effects of the automobile mode. Moreover, it was found that many cases have the potential to improve the overall LOS conditions, while reducing the automobile capacity. CONCLUSIONS: With the introduction of the multimodal LOS system, road diet and complete streets can be easily applied to ans actual road improvement project. Ultimately, the multimodal LOS system should be introduced into the KHCM, which can then be applied to traffic impact studies and other road improvement projects for more accurate evaluations.

• 한국도로학회논문집
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• 제16권4호
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• pp.75-86
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• 2014

PURPOSES: The aim of this paper is developing user-oriented flexible Level Of Service (LOS) system for integrated asset management of various road facilities. It is essential to overcome limitations of general management systems which only focus on a type of assets (e.g. pavement, bridge etc.), and to serve a customizable LOS platform for smooth implementation and future improvement of the LOS considering various managerial environments of road agencies. METHODS: This study suggested a total framework of the LOS system as a process for self-development, operation and improvement of LOS system to conduct the PDCA (Plan-Do-Check-Act) in management process. In the process, we adopted user-customizable elements regarding asset definition, service index and evaluation method to match with the managerial environment of road agencies. In addition, we conducted an empirical study on the entire process of the suggested LOS system with a real road agency (Korea Express Highway) to prove applicability of the LOS system. RESULTS: From the empirical study, we confirmed that the suggested LOS system framework were suitable for development of customized LOS system. In addition, evaluation of asset conditions by LOS ratings, and quantification of vision achievement of the Korea Express Highway were successfully made. It would be the first trial in integrated management approach with LOS systems for numerous road facilities. CONCLUSIONS : It was recognized that easy application and sustainable improvement of the LOS was the most critical point in asset management. The suggested LOS system would be a powerful weapon as a managerial tool in preparing tight budget, aging infrastructures, and increased demands for more accountability both in Korea and internationally. Implementation of the LOS system needs to be expanded to the other infrastructure members to serve satisfactory level of service to taxpayers.

• 제어로봇시스템학회논문지
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• 제11권4호
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• pp.363-368
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• 2005

This paper proposes an LOS(line-of-sight) guidance system of a ship for path following. From the viewpoint of a control configuration, guidance is a special type of compensation algorithm that is placed in front of the controller to accomplish navigational objects. A guidance system generates a reference trajectory for trajectory tracking or path control and decides the desired velocity, position and heading angle. A control system executes commands based on a reliable guidance law during navigation. An LOS vector from the vessel to a point on the path between two way-points in straight-line navigation or a point among turning circle in turning navigation is selected, and then a heading angle is calculated to converge the desired path based on the LOS vector. The LOS guidance law is defined for the straight-line and the turning circle, respectively. The effectiveness of the suggested LOS guidance system is assured through computer simulation.

• 디지털융복합연구
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• 제15권2호
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• pp.273-283
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• 2017

본 연구는 의료기관이 자체적으로 재원일수관리 활동을 하도록 유도하기 위해 외래정보로 재원일수를 예측하여 입원환자 재원일수를 예측하고 재원일수관리의 효율성을 제공할 수 있는 융복합 맞춤형 재원일수 관리 시스템을 개발 방안을 제시하고자 하였다. 외래정보 자료를 기반으로 개발된 재원일수 예측 모형을 이용한 융복합의 맞춤형 재원일수 관리 웹 프로그램은 실시간 예측 재원일수 산출되도록 구현되었다. 예측 모형을 기반으로 장기재원예측 환자군, 집중 관리 환자군 등 재원일수관리 서비스 대상이 도출되었다. 장기재원예측 환자군, 집중관리 환자군에 장기 재원 예상 알림 서비스, 재원일수 초과 알림 서비스 등을 제공할 수 있어 맞춤형 재원일수 관리 시스템이 맞춤형 재원일수 관리에 효율적인 시스템인 것이 확인되었다. 이에 융복합 맞춤형 재원일수 관리 시스템 웹 활용을 위해서는 재원일수 예측 질환의 확대와 국가 차원의 시범운영 정책 추진 방안이 필요하다.

• 제어로봇시스템학회논문지
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• 제7권12호
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• pp.1024-1030
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• 2001

In this paper, a horizontal LOS(line of sight) rate estimator for conventional sea skimming ASM(anti-ship missile) is proposed. A LOS rate dynamics model for a 2-axis gimbal system and the homing geometry is derived. A new LOS rate estimator is proposed by applying the Kalman filter theory to the LOS rate dynamics model. The proposed filter estimates LOS rates by taking roll motions into account. Simulation results show that the proposed filter produces smaller estimation errors than a conventional method.

• 한국군사과학기술학회지
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• 제13권4호
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• pp.642-649
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• 2010

LOS analysis is used for optimal deployment of mid-range guided weapon system or system engagement effectiveness simulation. Comparing to real-world, LOS analysis includes error sources such as coarse terrain data resolution, refraction of radio waves, and several ideal assumptions. In this research, exact LOS algorithm under assumption of constant earth curvature and error analysis of that is investigated. It proved that LOS algorithm under assumption of constant earth curvature has negligible error in mid-range guidance weapon system's scope.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1594-1611
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• 2008

도로의 경우, 서비스 수준은 A에서 F까지로 구분되어 있다. (도로용량 편람, 건교부). 장래 도로시설 계획 시, 시간당 교통량과 용량을 기준으로 하여 고속도로의 경우 서비스 수준 C를, 국도의 경우 D를 목표로 삼고 있는 실정이다. LOS C의 경우 용량의 약 75%수준에 해당되는 수준이다. 하지만, 철도의 경우는 현재까지 서비스 수준에 대한 개념이 정리되어 있지 못하고 있을 뿐만 아니라, 철도시설 계획 시에는 하루수요를 사용하고 있으며, 구체적인 서비스 수준을 고려하고 있지 못한 실정이다. 철도의 계획 시 용량과 서비스 수준은 결국 운영자와 승객의 입장에서 어느 정도의 철도서비스를 제공할 것인지에 대한 공감대를 형성하는 매우 중요한 사항임에도 불구하고, 명시적으로 서비스 수준을 고려하지 못하고 있는 현실이다. 또한 사용자의 수요의 발현도 결국은 철도서비스의 질에 달려 있는 점을 고려하면 철도서비스 수준을 명시적으로 고려하는 게 기대할 수 있는 수요를 정확하게 계산할 수 있도록 해 줄 것이다.

• 디지털융복합연구
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• 제13권5호
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• pp.89-99
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• 2015

본 연구는 의료기관이 자체적으로 재원일수관리 활동을 하도록 유도하기 위해 타 의료기관과 재원일수 관리 수준을 비교하여 의료기관의 재원일수 수준을 평가하고 재원일수관리의 효율성을 제공할 수 있는 재원일수 벤치마킹 시스템을 개발 방안을 제시하고자 하였다. 퇴원손상심층조사 자료를 기반으로 개발된 재원일수 중증도 모형을 이용한 융복합의 재원일수 벤치마킹 웹 프로그램은 병상 규모별, 지역별 비교되도록 구현되었고, 엑셀 파일 다운로드와 함께 리포트기능도 추가되었다. 또 실시간 중증도 보정 재원일수 산출 기능도 구현되었다. 시범운영 결과, 병원 운영진 또는 해당 임상 과로부터 질환별, 지역별 비교통계를 요청받으므로, 재원일수 벤치마킹 시스템이 장기재원관리, 질환별 재원관리 등 재원일수 관리에 효율적인 시스템인 것이 확인되었다. 이에 재원일수 벤치마킹 시스템 웹 활용을 위해서는 중증도 보정 질환의 확대와 국가 차원의 정책 추진 방안이 필요하다.

• 제어로봇시스템학회논문지
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• 제20권10호
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• pp.1014-1022
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• 2014

In mechatronic systems using electric signals to drive control systems, driving signals including the frequency band of the unwanted signals, such as resonant frequencies and noise frequencies, can affect the accuracy of the controlled system and can cause serious damage to the system due to the resonance phenomenon of the mechatronic system. An LOS (Line of Sight) control unit is used to automatically rotate the gimbal system with a video imaging system generally mounted on modern aerial vehicles. However, it still suffers from natural frequency variation problems due to variations of operational temperature. To prevent degradation in performance, this paper proposes an adaptive filtering technique based on real-time noise analysis and adaptive notch-filtering for LOS control systems, and verifies how our proposed method maintains the LOS stabilization performance. Additionally, this filtering technique can be applied to the image noise filtering of the video imaging system. It is designed to reduce image noises generated by switching circuits or power sources. The details of design procedures of the proposed filtering technique and the experiments for the performance verification are described in this paper.