• 제목/요약/키워드: Manufacturing Systems Engineering

검색결과 2,095건 처리시간 0.033초

Bending and stability information of cylindrical structures in the application of sports equipment

  • Xiaoyuan Liu;Radzliyana Radzuwan;Nadiah Diyana Tan Binti Abdullah
    • Advances in concrete construction
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    • 제16권4호
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    • pp.189-203
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    • 2023
  • This study investigates the bending and stability properties of cylindrical constructions, with a focus on their use in the design and implementation of sporting equipment. The work focuses on a cylindrical construction resembling nanomotors, similar to components seen in sports equipment, using mathematical modeling based on high-order beam theory and nonlocal strain gradient theory. The analysis provides important insights into the dynamic behavior of these systems, revealing light on the impact of numerous factors such as rotational velocity, section change rate, and structural dimensions. The results show a relationship between angular velocity growth and section change rate, which leads to an increase in fundamental frequency values. Furthermore, the research emphasizes the effect of structural factors on dynamic deflection, giving critical information for increasing the stability and performance of sporting equipment. This study adds to the area of sports engineering by providing a more nuanced understanding of how cylindrical constructions react under diverse settings. The results will help to guide the design and manufacturing processes of sports equipment, assuring improved stability and performance for players across a wide range of sports.

카메라 기반 객체의 위치인식을 위한 왜곡제거 및 오검출 필터링 기법 (Distortion Removal and False Positive Filtering for Camera-based Object Position Estimation)

  • 진실;송지민;최지호;진용식;정재진;이상준
    • 대한임베디드공학회논문지
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    • 제19권1호
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    • pp.1-8
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    • 2024
  • Robotic arms have been widely utilized in various labor-intensive industries such as manufacturing, agriculture, and food services, contributing to increasing productivity. In the development of industrial robotic arms, camera sensors have many advantages due to their cost-effectiveness and small sizes. However, estimating object positions is a challenging problem, and it critically affects to the robustness of object manipulation functions. This paper proposes a method for estimating the 3D positions of objects, and it is applied to a pick-and-place task. A deep learning model is utilized to detect 2D bounding boxes in the image plane, and the pinhole camera model is employed to compute the object positions. To improve the robustness of measuring the 3D positions of objects, we analyze the effect of lens distortion and introduce a false positive filtering process. Experiments were conducted on a real-world scenario for moving medicine bottles by using a camera-based manipulator. Experimental results demonstrated that the distortion removal and false positive filtering are effective to improve the position estimation precision and the manipulation success rate.

대형이산 행렬 시스템의 초대형병렬컴퓨터에서의 해법을 위한 병렬준비 행렬의 비교 (Comparison of Parallel Preconditioners for Solving Large Sparse Linear Systems on a Massively Parallel Machine)

  • 마상백
    • 한국정보처리학회논문지
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    • 제2권4호
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    • pp.535-542
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    • 1995
  • 이 논문에서 우리는 CM-5와 같은 초대형병렬컴퓨터에서 대형 이산선형체제를 풀기 위한 준비행렬로써 두 가지를 소개한다. 대다수의 초대형병렬컴퓨터들은 프로세서간의 통신을 메세지패씽(messagepassing)에 의존하는데 현재의 기술수준하에서는 이 통신속 도가 실수계산속도에 비해 매우 느리므로 종래의 메모리공유컴퓨터에서와는 달리 데이 터통신량을 최소화하는 알고리듬이 요구된다. 블록 SOR에 다중색채기법을 가미한 알고 리듬이 그 한 예로써 우리는 이를 CM-5에서 구현한 결과 N=512x512 행렬에서 프로세서 의 수가 16에서 512의 범위 하에서 50%의 효율을 실현하였다. 반면 종래의 효율적인 병렬 준비행렬로 알려진 AKI알고리듬은 방대한 량의 데이터통신 때문에 매우 열등한 결과를 보여준다.

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공리적 설계를 이용한 비대칭 내부 짐벌을 가진 진동형 자이로스코프의 강건설계 (Robust Design of the Vibratory Gyroscope with Unbalanced Inner Torsion Gimbal Using Axiomatic Design)

  • 박경진;황광현;이권희;이병렬;조용철;이석한
    • 대한기계학회논문집A
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    • 제26권5호
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    • pp.914-923
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    • 2002
  • Recently, there has been considerable interest in micro gyroscopes made of silicon chips. It can be applied to many micro-electro-mechanical systems (MEMS): devices for stabilization, general rate control, directional pointing, autopilot systems, and missile control. This paper shows how the mechanical design of the gyroscope can be done using axiomatic design, followed by the application of the Taguchi robust design method to determine the dimensions of the parts so as to accommodate the dimensional variations introduced during manufacturing. Functional requirements are defined twofold. One is that the natural frequencies should have fixed values, and the other is that the system should be robust to large tolerances. According to the Independence Axiom, design parameters are classified into a few groups. Then, the detailed design process is performed fellowing the sequence indicated by the design matrix. The dimensions of the structure are determined to have constant values fur the difference of frequencies without consideration of the tolerances. It is noted that the Taguchi concept is utilized as a unit process of the entire axiomatic approach.

다변량 목표변수를 갖는 의사결정나무의 노드분리에 관한 연구 (A Study on the Node Split in Decision Tree with Multivariate Target Variables)

  • 김성준
    • 한국지능시스템학회논문지
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    • 제13권4호
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    • pp.386-390
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    • 2003
  • 데이터마이닝은 많은 양의 데이터로부터 의사결정에 유용한 패턴을 발견하는 과정으로서 최근 경영 및 공학 분야의 폭넓은 영역에서 많은 관심을 모으고 있다. 어떤 그룹을 여러 하위그룹으로 분류해내는 일은 데이터마이닝의 주요 내용 중 하나이다. 의사결정나무로 알려진 트리기반 기법은 그러한 분류모형을 수립하는 데 효율적인 방안을 제공한다 트리학습에 있어서 우선적인 관건은 목표변수에 의해 측정되는 노드불순도를 최소화하는 것이다. 하지만 공정관측, 마케팅과학, 임상분석 등과 같은 문제에서는 여러 목표변수를 동시에 고려해야 하는 상황이 쉽게 등장하는 데, 본 논문의 목적은 이처럼 다변량 목표변수를 갖는 데이터셋에서 활용할 수 있는 노드불순도 측정방안을 제시하는 데 있다. 아울러 수치 예를 이용하여 적용결과에 대해 논의한다.

인공지능형 삼차원 Foot Scanning 시스템에 관한 연구 (A Study on the Intelligent 3D Foot Scanning System)

  • 김영탁;박주원;탁한호;이상배
    • 한국지능시스템학회논문지
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    • 제14권7호
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    • pp.871-877
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    • 2004
  • 본 논문은 맞춤형 신발제작을 위하여 신발에 필요한 화형제작용 데이터를 3차원 측정 장치를 통해 획득한 발의 형상을 인공지능 기법을 기반으로 하는 최적화된 형상을 복원하는 방법을 제시하고자 한다. 본 연구를 위해 개발된 시스템은 PC를 기반으로 하는 기존의 3차원측정 방식을 이용하여 상, 하, 좌, 우로 각각 장착된8대의 CCD 카메라와 4대의 laser를 통해 화형 및 발의 형상 데이터를 획득한다. 획득된 데이터들은 인공지능 기법을 이용한 영상처리 알고리즘으로 처리되며, 처리 결과는 기존의 지능 기법을 도입하지 않은 시스템에 비해 노이즈제거 특성이 향상되었고, 후처리과정을 간소화 할 수 있다. 따라서 본 논문에서는 3차원 측정을 위해 하드웨어적인 부분과 이를 제어하기 위한 소프트웨어 및 GUI로 전체 시스템을 구성하고, 본 논문에서는 데이터 처리용 소프트웨어에서 입력영상의 전처리 과정 중 영상의 이진화 단계에서 임계값을 결정하기 위하여 신경망을 사용하였으며, 이에 대한 결과를 제시하고자 한다.

위치기반 유사도 검증을 이용한 도로표지 안내지명 자동인식 개선방안 연구 (A Study on the Improvement of Automatic Text Recognition of Road Signs Using Location-based Similarity Verification)

  • 정규수
    • 한국ITS학회 논문지
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    • 제18권6호
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    • pp.241-250
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    • 2019
  • 도로표지는 도로 이용자를 위한 시설물로서 관리 및 유지보수의 편의성 증진을 위해 국토교통부에서는 관리시스템을 구축하여 운영 중에 있다. 향후 자율주행 시대에 도로표지의 역할은 감소하겠지만 그 필요성은 지속되고 있다. 이에 도로표지에 표기된 안내지명의 정확한 기계적 판독을 위해 도로표지 자동인식 장비를 개발하여 영상 기반의 문자 인식 기술을 적용하고 있지만 불규칙적인 규격과 수작업 제조, 조도, 빛반사, 강우 등 외부환경에 의해 오인식되는 경우가 다수 발생하고 있다. 본 연구에서는 영상 분석 등으로 극복할 수 없는 오인식 결과를 개선하기 위해 위치기반의 안내지명 후보를 도출하여 기준으로 하고, 오인식된 지명의 음소 분리를 통한 레벤슈타인 문자 유사도 검증 방법을 이용해 도로표지 안내지명 자동인식율을 개선하고자 하였다.

Investigation of 0.5 MJ superconducting energy storage system by acoustic emission method.

  • Miklyaev, S.M.;Shevchenko, S.A.;Surin, M.I.
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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    • pp.961-965
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    • 1998
  • The rapid development of small-scale (1-10 MJ) Superconducting Magnetic Energy Storage Systems (SMES) can be explained by real perspective of practical implementation of these devices in electro power nets. However the serious problem of all high mechanically stressed superconducting coils-problem of training and degradation (decreasing) of operating current still exists. Moreover for SMES systems this problems is more dangerous because of pulsed origin of mechanical stresses-one of the major sources of local heat disturbances in superconducting coils. We investigated acoustic emission (AE) phenomenon on model and 0.5 MJ SMES coils taking into account close correlation of AE and local heat disturbances. Two-coils 0.5 MJ SMES system was developed, manufactured and tested at Russian Research Center in the frames of cooperation with Korean Electrical Engineering Company (KEPCO) [1]. The two-coil SMES operates with the stored energy transmitted between coils in the course of a single cycle with 2 seconds energy transfer time. Maximum operating current 1.55 kA corresponds to 0.5 MF in each coil. The Nb-Ti-based conductor was designed and used for SMES manufacturing. It represents transposed cable made of Nb-Ti strands in copper matrix, several cooper strands and several stainless steel strands. The coils are wound onto fiberglass cylindrical bobbins. To make AE event information more useful a real time instrumentation system was used. Two main measured and computer processed AE parameters were considered: the energy of AE events (E) and the accumulated energy of AE events (E ). Influence of current value in 0.5 MJ coils on E and E was studied. The sensors were installed onto the bobbin and the external surface of magnets. Three levels of initial current were examined: 600A, 1000A, 2450 A. An extraordinary strong dependence of the current level on E and E was observed. The specific features of AE from model coils, operated in sinusoidal vibration current changing mode were investigated. Three current frequency modes were examined: 0.012 Hz, 0.03 Hz and 0.12 Hz. In all modes maximum amplitude 1200 A was realized.

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설비공학 분야의 최근 연구 동향 : 2013년 학회지 논문에 대한 종합적 고찰 (Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2013)

  • 이대영;김사량;김현정;김동선;박준석;임병찬
    • 설비공학논문집
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    • 제26권12호
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    • pp.605-619
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    • 2014
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2013. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and relative parts including orifices, dampers and ducts, fuel cells and power plants, cooling and air-conditioning, heat and mass transfer, two phase flow, and the flow around buildings and structures. Research issues dealing with home appliances, flows around buildings, nuclear power plant, and manufacturing processes are newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for general analytical model for desiccant wheels, the effects of water absorption on the thermal conductivity of insulation materials, thermal properties of Octadecane/xGnP shape-stabilized phase change materials and $CO_2$ and $CO_2$-Hydrate mixture, effect of ground source heat pump system, the heat flux meter location for the performance test of a refrigerator vacuum insulation panel, a parallel flow evaporator for a heat pump dryer, the condensation risk assessment of vacuum multi-layer glass and triple glass, optimization of a forced convection type PCM refrigeration module, surface temperature sensor using fluorescent nanoporous thin film. In the area of pool boiling and condensing heat transfer, researches on ammonia inside horizontal smooth small tube, R1234yf on various enhanced surfaces, HFC32/HFC152a on a plain surface, spray cooling up to critical heat flux on a low-fin enhanced surface were actively carried out. In the area of industrial heat exchangers, researches on a fin tube type adsorber, the mass-transfer kinetics of a fin-tube-type adsorption bed, fin-and-tube heat exchangers having sine wave fins and oval tubes, louvered fin heat exchanger were performed. (3) In the field of refrigeration, studies are categorized into three groups namely refrigeration cycle, refrigerant and modeling and control. In the category of refrigeration cycle, studies were focused on the enhancement or optimization of experimental or commercial systems including a R410a VRF(Various Refrigerant Flow) heat pump, a R134a 2-stage screw heat pump and a R134a double-heat source automotive air-conditioner system. In the category of refrigerant, studies were carried out for the application of alternative refrigerants or refrigeration technologies including $CO_2$ water heaters, a R1234yf automotive air-conditioner, a R436b water cooler and a thermoelectric refrigerator. In the category of modeling and control, theoretical and experimental studies were carried out to predict the performance of various thermal and control systems including the long-term energy analysis of a geo-thermal heat pump system coupled to cast-in-place energy piles, the dynamic simulation of a water heater-coupled hybrid heat pump and the numerical simulation of an integral optimum regulating controller for a system heat pump. (4) In building mechanical system research fields, twenty one studies were conducted to achieve effective design of the mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, and renewable energies in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment is mostly focused on indoor environment and building energy. The main researches of indoor environment are related to infiltration, ventilation, leak flow and airtightness performance in residential building. The subjects of building energy are worked on energy saving, operation method and optimum operation of building energy systems. The remained studies are related to the special facility such as cleanroom, internet data center and biosafety laboratory. water supply and drain system, defining standard input variables of BIM (Building Information Modeling) for facility management system, estimating capability and providing operation guidelines of subway station as shelter for refuge and evaluation of pollutant emissions from furniture-like products.

ANSIM 문서관리시스템에서 연구로사업 문서흐름 (Document Flow for the Research Reactor Project in ANSIM Document Control System)

  • 박국남;김권호;김준연;우상익;오수열
    • 산업경영시스템학회지
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    • 제36권4호
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    • pp.18-24
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    • 2013
  • A document control system (DCS), ANSIM (KAERI Advanced Nuclear Safety Information Management) was designed for the purpose of documents preparation, review, and approvement for JRTR (Jordan Research and Training Reactor) project. The ANSIM system consists of a document management, document container, project management, organization management, and EPC (Engineering, Procurement and Construction) document folder. The document container folder run after specific contents, a revision history of the design documents and drawings are issued in KAERI. The EPC document work-scope is a registry for incoming documents in ANSIM, the assignment of a manager or charger, document review, preparing and outgoing PM memorandum as attached the reviewed paper. On the other hand, KAERI is aiming another extra network server for the NRR (New Research Reactor) by the end of this year. In conclusion, it is the first, computation system of DCS that provides document form, document number, and approval line. Second, ANSIM increases the productivity of performance that can be recognized the document work-flow of oneself and all participants. Finally, a plenty of experience and knowledge of nuclear technology can be transmitted to next generation for the design, manufacturing, testing, installation, and commissioning. Though this, ANSIM is expected to allow the export of a knowledge and information system as well as a research reactor.