• 드라이브 ㆍ 컨트롤
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• 제15권4호
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• pp.30-38
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• 2018

Electronic control units (ECUs) are currently popular, and have evolved further towards the high-end application of autonomous vehicles in the automotive industry. Such digital technologies have also become widespread, in agriculture and construction equipment. Likewise, transmission control of high-speed tracked vehicles is based on the transmission control unit (TCU), performing complex gear change control functions, and diagnostic algorithms (a TCU's self-diagnostic and reporting capability of malfunction data through CAN communication). Since all functions of TCU are implemented by embedded-software, it is hardly possible to analyze specifications by reverse engineering. In this paper a real-time transmission simulator adaptable to TCU is presented, for analysis of diagnosis algorithm and standards. Signal simulation circuits are deliberately designed considering electrical characteristics of TCU inputs and various analysis tools, such as analog input auto scan function, and global output enable switch, are implemented in software. Test results from hardware-in-the-loop simulator verify tolerance time for each error, as well as cause of fault, error reset conditions.

• Nuclear Engineering and Technology
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• 제54권6호
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• pp.2147-2155
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• 2022

Nuclear safety-related underground liquid storage tanks, such as those used to store fuel for emergency diesel generators, are critical components for safety of hundreds of existing nuclear power plants (NPP) worldwide. Since most of those NPP will continue to operate for decades, a beyond design base (BDB) seismic screening of safety-related underground tanks in those NPP is beneficial and essential to public safety. The analytical methodology for buried tank subjected to seismic effect, including a BDB seismic evaluation, needs to consider both soil-structure and fluid-structure interaction effects. Comprehensive analysis of such a soil-structure-fluid system is costly and time consuming, often subjected to availability of state-of-art finite element tools. Simple, but practically and reasonably accurate techniques for seismic evaluation of underground liquid storage tanks have not been established. In this study, a mechanics based solution is proposed for the evaluation of a cylindrical underground liquid storage tank using hand calculation methods. For validation, a practical example of two underground diesel fuel tanks in an existing nuclear power plant is presented and application of the proposed method is confirmed by using published results of the computer-aided System for Analysis of Soil Structural Interaction (SASSI). The proposed approach provides an easy to use tool for BDB seismic assessment prior to making decision of applying more costly technique by owner of the nuclear facility.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.331-337
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• 2009

This paper summarizes some of approaches that could be taken for data exchange in a non-interoperable work environment and reports lessons learned from the Dongdaemun Design Plaza and Park project. Today's widespread application of building information modeling (BIM) to the construction and architectural design industries requires a change in the cooperation between business organizations and their methods of communication. In particular, the interoperability of information between interdisciplinary organizations, which use specific programs for different purposes, has become a critical issue. More than just a technical problem, it is also highly related to an organization's collaboration culture and the particulars of a specific project. This paper describes the interoperability issue that occurred during the construction documentation phase of the irregularly shaped building project, Dongdaemun Design Plaza and Park, designed by Zaha Hadid Architects and Samoo Architects and Engineers, from the perspective of the technological problem and the collaborative organizations' communications. Although the perfect compatibility of information is not possible, this paper deals with a practical approach to the interoperability issue by examining the way the end-users of computer-aided design (CAD) resolved the interoperability problems in practice.

• 한국산학기술학회논문지
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• 제16권1호
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• pp.507-515
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• 2015

본 연구는 초음파영상에서 컴퓨터보조진단으로 유방질환의 병변인식률을 알아보고자 6가지 질감특성분석 파라미터(평균밝기, 대조도, 평탄도, 왜곡도, 균일도, 엔트로피) 알고리즘을 제안하였다. 2013년 8월에서 2014년 1월까지 부산소재 대학병원을 내원한 환자 중 영상의학과 전문의의 판독과 세포병리학 진단 결과를 토대로 한 90증례의 유방 초음파영상을 대상으로 하였다. 연구방법은 유방 초음파영상에서 관심영역을 $50{\times}50$ 픽셀 크기로 설정하였으며, 획득된 실험영상(정상, 양성, 악성)에 히스토그램 평활화의 전처리 과정 후 MATLAB을 이용한 질감특성분석 알고리즘의 결과값을 산출하였다. 그 결과 제안된 질감특성분석 파라미터 중 평균밝기, 왜곡도, 균일도, 엔트로피의 정상과 악성의 병변인식률은 100%로 높게 나타났으며. 정상과 양성의 병변인식률은 약 83~96%를 나타내었다. 이러한 결과는 유방질환에서 감별진단의 전처리 단계로 자동진단의 가능성을 나타내며, 향후 제안된 알고리즘의 추가적인 연구와 다양한 임상증례에 대한 신뢰성과 재현성이 제공된다면 컴퓨터보조진단의 실용화기반을 마련할 수 있을 것이고, 다양한 초음파 영상에 대한 적용이 가능할 것으로 사료된다.

• 대한치과보철학회지
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• 제59권1호
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• pp.43-54
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• 2021

디지털기술의 급격한 발전으로 보철 수복치료에 있어서도 많은 기술들이 활용되고 있다. 특히 최근에는 구강스캐너와 3D printing 기술이 광범위하게 사용되고, 더 나아가 안면스캔 기술 또한 접목되어 활용되고 있다. 본 증례는 37세 여성환자에서 전통적인 방식으로 제작되고 장착되어 충분히 평가된 전악 고정성 임시수복상태를 구강스캐너와 안면스캐너, 3D printing 등의 다양한 디지털 기술을 활용하여 안모와 조화를 이루는 최종보철물로 이행하는 과정을 거쳤다. 이를 통해 안정적인 교합을 회복하고 기능적, 심미적으로 만족할만한 결과를 얻었기에 보고하는 바이다.

• 대한치과보철학회지
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• 제59권1호
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• pp.116-125
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• 2021

디지털 치의학에서의 주요한 발전 중 하나인 3차원 구강스캐너는 최근 고정성 보철물에 널리 사용되고 있으며 가철성 보철물에서도 사용이 증가하고 있다. 전신성 피부경화증에 의한 안면부 연조직의 경화는 개구량 제한을 일으켜 치아상실을 야기하며 기존의 통상적인 보철 치료를 어렵게 한다. 본 증례에서는 디지털 치의학의 발전을 통한 3차원 구강스캐너를 이용하여 개구량 제한과 그에 따른 소구증을 가진 전신성 피부경화증 환자에서 3차원 구강구조를 광학인상 채득하고, 이를 바탕으로 3D 프린터를 이용한 임시의치 제작을 통해 3차원 구강스캐너를 통한 가철성 보철물 제작의 가능성을 확인하였다. 이후 최종 지대치 정리 후 최종 광학인상 채득하여 국소의치 금속구조물을 제작하였다. 금속구조물의 적합도는 임상적으로 만족스러웠으며 이후 최종 국소의치 제작, 장착하여 상실부위에 대한 수복을 진행, 임상적으로 만족스러운 결과를 얻을 수 있었다.

• 대한치과보철학회지
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• 제60권2호
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• pp.222-230
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• 2022

디지털 기술은 점차 그 영역을 넓혀 치의학의 여러 분야에 큰 영향을 미치고 있다. 최근 디지털 치의학에서는 다양한 삼차원적(3D) 이미지 데이터를 하나로 중첩시켜 진단 및 보철물 제작에 활용하는 것의 중요성이 대두되고 있다. 안면 스캔, 구내 스캔, 하악 운동 기록(mandibular movement recording) 등의 데이터를 통합하면 가상 환자 모델을 구성할 수 있다. 가상 환자(Virtual patient)란 구내 및 구외 연조직, 잔존 치열, 동적 교합 등 디지털 3D 진단 데이터를 통합하여 형성되며 이를 통해 보철 치료의 결과 등을 가상으로 시뮬레이션을 시행할 수 있다. 본 증례에서의 환자는 37세 여성 및 55세 여성 환자로 각각 기존 보철물의 외형이 틀어진 것 같다는 주소와 근관치료 후 전치부 보철물의 재제작을 주소로 내원하였다. 각 환자에서 3D 안면 스캔을 채득하였으며, ARCUS Digma 2 (KaVo Dental GmbH, Biberach an der Riss, Germany)를 통해 환자의 하악 운동을 기록하였다. 수집한 데이터를 computer-aided design (CAD) 소프트웨어(Exocad dental CAD; exocad GmbH, Darmstadt, Germany) 상에서 하나로 통합하여 가상 교합기에 옮겨 디지털 가상 환자를 형성하였다. 이를 통해 임시 고정성 보철물을 디자인하고 수복하여 평가하였으며, 최종수복물로 옮겨 심미적, 기능적으로 만족할 만한 결과를 보였기에 이를 보고하고자 한다.

• 대한치과교정학회지
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• 제24권3호
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• pp.735-758
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• 1994

This study was designed to investigate the displacements and reaction forces of teeth caused by the application of the rectangular shape-memory arch wires with curve of Spee. Computer-aided three dimensional finite element method was adopted. This finite element model consists of brick element for teeth, beam element for the wire, and contact element for the periodontal ligament. And the application of the MEAW(Multiloop Edgewise Arch Wire) was also studied so that the results of the two methods can be compared each other. Total number of the nodes and elements were found to be 5925 and 4031, repectively. In addition, several types of elastics and corresponding displacements and reaction forces were examined. The findings of this study were as follows: 1. When the rectangular shape-memory arch wire with curve of Sun was used alone, the intrusion and labioversion was noticeable on the upper incisors, while the upper molars showed less intrusion. With MEAW, the intrusion and labioversion of the upper incisors were slightly larger than those when the shape-memory arch wire was used, but on the upper molars the opposite result was obtained with respect to the intrusion. 2. The shape-memory arch wire with the vertical elastics caused the larger downward displacement on the upper canine than that when the MEAW was used with the vertical elastics. However, the downward displacement of the upper incisors was larger in MEAW. The uprighting and buccoversion of the molars were observed in both cases. 3. The use of the Class II or III elastics showed the extrusion and changes in torque of the corresponding teeth. The downward displacement of the upper canine was increased when the Class II and vertical elastics were applied simultaneously, but it was decreased when both of the Class III and vertical elastics were used.

• 제어로봇시스템학회논문지
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• 제7권8호
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• pp.689-696
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• 2001

Large-scale Multi-disciplinary Systems(LMS) such as transportation, aerospace, defense etc. are complex systems in which there are many subsystems, interfaces, functions and demanding performance requirements. Because many contractors participate in the development, it is necessary to apply methods of sharing common objectives and communicating design status effectively among all of the stakeholders. The processes and methods of systems engineering which includes system requirement analysis; functional analysis; architecting; system analysis; interface control; and system specification development provide a success-oriented disciplined approach to the project. This paper shows not only the methodology and the results of model-based systems engineering to Automated Guided Transit(AGT) system as one of LMS systems, but also propose the extension of the model-based tool to help manage a project by linking WBS (Work Breakdown Structure), work organization, and PBS (Product Breakdown Structure). In performing the model-based functional analysis, the focus was on the operation concept of an example rail system at the top-level and the propulsion/braking function, a key function of the modern automated rail system. The model-based behavior analysis approach that applies a discrete-event simulation method facilitates the system functional definition and the test and verification activities. The first application of computer-aided tool, RDD-100, in the railway industry demonstrates the capability to model product design knowledge and decisions concerning key issues such as the rationale for architecting the top-level system. The model-based product design knowledge will be essential in integrating the follow-on life-cycle phase activities. production through operation and support, over the life of the AGT system. Additionally, when a new generation train system is required, the reuse of the model-based database can increase the system design productivity and effectiveness significantly.

• International Journal of Fluid Machinery and Systems
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• 제4권2호
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• pp.271-288
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• 2011

The mathematical modelling of screw compressor processes and its implementation in their design began about 30 years ago with the publication of several pioneering papers on this topic, mainly at Purdue Compressor Conferences. This led to the gradual introduction of computer aided design, which, in turn, resulted in huge improvements in these machines, especially in oil-flooded air compressors, where the market is very competitive. A review of progress in such methods is presented in this paper together with their application in successful compressor designs. As a result of their introduction, even small details are now considered significant in efforts to improve performance and reduce costs. Despite this, there are still possibilities to introduce new methods and procedures for improved rotor profiles, design optimisation for each specified duty and specialized compressor design, all of which can lead to a better product and new areas of application. A review of methods and procedures which lead to modern screw compressor practice is presented in this paper. This paper is intended to give a cross section through activities being done in mathematical modelling of screw compressor process through last five decades. It is expected to serve as a basis for further contributions in the area and as a challenge to the forthcoming generations of scientists and engineers to concentrate their efforts in finding future and more extended approaches and submit their contributions.