• Earthquakes and Structures
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• 제15권3호
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• pp.263-273
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• 2018

Operational modal analysis is being widely used in aerospace, mechanical and civil engineering. Common research fields include optimal design and rehabilitation under dynamic loads, structural health monitoring, modification and control of dynamic response and analytical model updating. In many practical cases, influence of noise contamination in the recorded data makes it difficult to identify the modal parameters accurately. In this paper, an improved frequency domain method called Enhanced Least Square Complex Frequency (eLSCF) is developed to extract modal parameters from noisy recorded data. The proposed method makes the use of pre-defined approximate mode shape vectors to refine the cross-power spectral density matrix and extract fundamental frequency for the mode of interest. The efficiency of the proposed method is illustrated using an example five story shear frame loaded by random excitation and different noise signals.

• 한국ITS학회 논문지
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• 제22권2호
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• pp.195-211
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• 2023

자율주행자동차(Automated Vehicle, AV)의 상용화를 위해서는 ADS의 운행가능영역(Operational Design Domain, ODD)이 명확하게 정의되어야 하며, AV 관련 이해관계자들이 ODD에 대해 모두가 동일한 기준을 가지고 동일한 수준으로 이해할 수 있도록 공통된 언어와 일관된 양식이 마련되어야 한다. 따라서, 국외에서는 표준화된 ODD 프레임워크를 제시하고, ODD를 기반으로 ADS 특정 기능을 평가할 수 있는 시나리오 개발에 박차를 가하고 있다. 하지만, ODD는 도로환경, 기상환경, 교통환경 등 해당 국가별 특성이 반영된 조건이 포함되기 때문에 국외에서 정의된 항목을 그대로 적용하는 것이 아니라, 그 항목의 의미를 명확히 이해하고 국내의 여건을 반영하여 이를 정합화할 필요가 있다. 따라서, 본 연구에서는 국제표준을 기반으로 국내 주행환경을 분석하여 ODD 분류 체계 국내 최적화를 수행하였으며, 개발된 국내 ODD 항목을 기반으로 현재 운영 중인 자율주행차 시범운행지구(서울 상암, 광주)의 주행환경을 조사하고 그 결과를 바탕으로 시험운행지구별 ODD의 범위를 비교하였다.

• Journal of Semiconductor Engineering
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• 제1권2호
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• pp.64-73
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• 2020

As CMOS technology scales down, the design of analog signal processing circuit becomes far more difficult because of steadily decreasing supply voltage and smaller intrinsic gain of transistors. With sub-1V supply voltage, the conventional analog signal processing relying on high-gain amplifiers is not an effective solution and different approach has to be sought. One of the promising approaches is "time-domain analog signal processing" which exploits the improving switching speed of transistors in a scaled CMOS technology. In this paper, various time-domain analog signal processing techniques are explained with some experimental results.

• 한국ITS학회 논문지
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• 제21권6호
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• pp.299-310
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• 2022

자율주행시스템은 자율주행 센서, 판단 및 제어 알고리즘 등을 기반으로 스스로 자율주행할 수 있는 기능을 갖추고 있다. 자율주행의 안전성은 도로 네트워크의 운영 상태와 관련성이 높고 도로 인프라와의 협력이 필요하다. 자율주행의 안전한 운행을 위해서는 지속적으로 도로와 교통 조건이 적합한지를 모니터링 할 필요가 있다. 본 연구는 자율주행시스템의 ODD (Operational Design Domain) 특성에 따라 선정된 모니터링 항목을 관리할 수 있는 체계를 구축하기 위한 노드와 링크 체계를 제시하였다. 확장성을 고려하여 기존의 ITS 표준 노드링크 체계를 기반으로 하였으며, 모니터링 대상을 노드와 링크로 표출하는 방안을 제시하였다. 위험도를 5단계로 구분하고 관리하는 방안과 최적경로 탐색 및 통제 시 노드와 링크의 정보를 활용하는 방안을 제시하였다. 세종시를 대상으로 제시된 노드와 링크체계를 기반으로 한 시스템구축 사례를 소개하였다.

• Journal of Information Technology Applications and Management
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• 제25권3호
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• pp.29-41
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• 2018

The purpose of constructing university information system is for improvement in diversification and throughput of information, streamlines business processes, rapid exchange of information, sharing of information, decision-making information, and securing educational facilities. Similar to business information technology system, university information system does not have a review system for sharing and overlapping investment of information. Due to the lack of project management for outsourcing and vulnerability of system suitability, system audit is absolutely needed for the university information system. This paper especially focuses on an operational phase in the audit of university information system. Additionally, we proposed operating model and checklists of the university information system based on Management Guidelines of ITIL V3 Operational and Information System. We derived the checklists of operation audit by each domain of service strategy, service design, service transition, service operation, and continual service improvement. As the result, this study appear to have more than average satisfaction the suitability results were.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.38-40
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• 2007

In this paper, we propose a novel architecture, which is based on DCT (Discrete Cosine Transform), for ME (Motion Estimation) and MC (Motion Compensation). The traditional algorithms of ME and MC based on DCT did not suffer the advantage of the coarseness of the 2-dimensional DCT (2-D DCT) coefficients to reduce the operational time. Therefore, we derive a recursion equation for transform-domain ME and MC and design the structure by using highly regular, parallel, and pipeline processing elements. The main difference with others is removing the IDCT block by using to transform domain. Therefore, the performance of our algorithm is more efficient in practical image processing such as DVR (Digital Video Recorder) system. We present the simulation result which is compare with the spatial domain methods. it shows reducing the calculation cost. compression ratio. and peak signal to noise ratio (PSNR).

• 한국ITS학회 논문지
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• 제21권5호
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• pp.197-217
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• 2022

자율주행자동차(Automated vehicle, AV) 교통사고가 지속적으로 발생하면서 자율주행시스템(automated driving system, ADS)의 안전성 및 신뢰성을 확보하기 위한 안전성 검증의 중요성이 강조되고 있다. 안전성 및 신뢰성을 확보하기 위해서는 ADS의 운행가능영역(operational design domain, ODD)을 정의하고 ODD를 벗어나는 상황에서의 대응 능력을 평가하면서 ADS의 안전성을 검증해야 할 필요가 있다. 이를 위해 SAE, BSI, NHTSA, ISO 등의 국제 기구에서는 ODD 분류 기준 및 표준을 규정하고 있으나 국내의 경우 ODD 기준이 부재하여 AV의 ODD 표현 방법 및 안전성 검증 및 평가가 적절히 이루어지지 않고 있다. 이에 본 연구에서는 해외 ODD 분류 기준을 분석하고 안전성 검증 및 평가에 적합한 분류 기준을 선정하였다. 선정된 ODD를 기반으로 ADS 안전성 검증 및 평가에 필요한 평가요소를 제시하였다. 특히, ADS 기술 개발을 지원하는 자율주행 실험도시(K-City)의 평가환경을 분석하여 평가요소를 제시하였다.

• 시스템엔지니어링학술지
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• 제6권2호
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• pp.29-35
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• 2010

In general, an Architecture of a system is embodied as applied results of a requirement analysis of a system in early development phase. These efforts play a important role in analyzing and understanding a system considering operational, functional, and physical view and deriving a correct solution before developing the system. In this paper, the architecture of the Tube Transportation System(TTS) known as the new transportation system in Railway Domain is depicted by performance parameter has already developed. The existing performance parameters are shown by a variety of types with many meanings rather than types of general requirements refined. As these early performance parameters have analyzed and complemented to a level of requirement by requirement managers and other domain specialists, the architecture of the Tube Transportation System was developed systematically and then system requirements will be drawn up definitely. The presented architecture will provide a framework of developing a TTS and also offer an information in performance analysis of TTS.

• 한국군사과학기술학회지
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• 제27권1호
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• pp.60-69
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• 2024

The importance of geospatial information is increasingly highlighted in the defense domain. Accurate and up-to-date geospatial data is essential for situational awareness, target analysis, and mission planning in millitary operations. The use of high-resolution geospatial data in military operations requires large storage and fast image processing capabilities. Efficient image processing is required for tasks such as extracting useful information from satellite images and creating 3D terrain for mission planning, In this paper, we designed a cloud-based operational situation mixed reality visualization system that utilizes large-scale geospatial information distributed processed on a cloud server based on the container orchestration platform Kubernetes. We implemented a prototype and confirmed the suitability of the design.

• 대한임베디드공학회논문지
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• 제19권2호
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• pp.115-121
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• 2024

Each ADS must have a validation and evaluation scenario for ODD. This requires a large number of scenarios, so a scenario library must be developed. In order to effectively utilize the scenario library, a system that supports testing in the ODD of the user's choice is required. In other words, in order to develop a scenario library, it is necessary to build a database on actual driving road conditions (geometry, etc.). Accordingly, in this study, we establish a domestic driving environment database based on HD-Map for driving safety testing, design a system that can search test target sections in connection with the ODD of the scenario, and present the implementation results. In the future, it is expected that the domestic driving environment database will be able to create scenarios through linking with the scenario library and directly utilize them for scenario-based evaluation of various demand sources.