• 제목/요약/키워드: LOM

검색결과 101건 처리시간 0.039초

LOM 공정에서의 제품 치수 오차 분석에 관한 연구 (Dimensional Error Analysis of Products from LOM Process)

  • 하성도;김경환;송용억;박태권;김창희
    • 한국정밀공학회지
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    • 제15권12호
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    • pp.89-96
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    • 1998
  • LOM (Laminated Object Manufacturing) process is one of rapid prototyping processes, where shapes are formed by accumulating cross sections of laser-cut paper. The process expects wide popularity since it is simple and the material is familiar to conventional mockup makers. However the dimensional accuracy of LOM parts is not so good as that of traditional wooden mockups, since the stack of adhesive-spread papers causes significant dimensional error. Also it is unclear how the other unknown environmental effects cause the errors as well. In this work the dimensional errors of LOM parts are measured and analysed. Experiments with test parts were performed in order to see the effects of part shape, moist, and sealer on dimensional variations. The characteristic of the paper is also analysed. Re-heating LOM parts, which is shown to have the effect of recovering dimensional changes, is applied to an example part.

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Sloped-LOM 방식 3D 프린터를 이용한 비정형 EPS 거푸집 제작 공법 개발 (Development of Method for Manufacturing Freeform EPS Forms Using Sloped-LOM Type 3D Printer)

  • 안희재;이동윤;지우종;이우재;조훈희
    • 한국건축시공학회지
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    • 제20권2호
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    • pp.171-181
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    • 2020
  • 최근 비정형 건축물이 한 나라의 기술적 우월성을 나타내는 새로운 척도로 부상하기 시작하면서 비정형 건축물을 효율적으로 제작하는 기술이 중요해지고 있다. 하지만 기존의 목재, 철재 거푸집 등을 CNC 기술로 가공하여 비정형 거푸집을 제작하는 방식은 제작시간과 재료 비용 측면에서 한계점이 존재한다. 따라서 본 연구에서는 S-LOM 방식의 3D 프린팅 기술을 통한 비정형 EPS 거푸집 제작 공법을 개발하고 제작 프로세스를 제시하였다. 또한 실물 모형 시험을 통해 기존 CNC 밀링 기술과의 제작시간 및 정밀도에 대한 비교 분석을 실시하였다. 연구결과, S-LOM 방식의 3D 프린팅 기술을 활용할 경우 CNC 밀링 기술 대비 약 57.4%의 제작시간 단축 효과가 있었다. 또한 S-LOM 방식의 3D 프린팅 기술의 경우 설계도면 대비 약 20.5mm의 오차의 최대 절댓값이 발생하였다. 본 연구의 결과는 거푸집 제작시간과 정밀도 측면에서 S-LOM 방식 기술의 현장 적용 가능성을 확인하여, S-LOM 방식 기술의 개선 및 공법 활성화에 기여할 수 있을 것으로 사료된다.

LOM 시스템을 이용한 패턴제작에 관한 연구 (A Study on Manufacturing Process of Pattern with LOM System)

  • 최만성;최배호
    • 한국정밀공학회지
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    • 제18권3호
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    • pp.47-52
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    • 2001
  • Rapid Prototyping(RP) has been widely applied in designing and developing process of new products. RP can reduce the lead time and expense required to bring a new product form initial concept to production. Among several RP process can dramatically reduce the total build time and be applied for fabrication of large-sized and free form object because it uses in LOM the paper thickness is 0.05∼0.38mm as deposition feature segment. In this study, mechanical properties of pattern with LOM system is studied for optimal design of sand mold casting. The main result is that tensile, compressive strength and pattern size are significantly affected by temperature of hot roll.

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분산 트레이더를 지원하는 경량 (lightweight) 객체 모델 설계 및 구현 방안 연구 (A Study on the Design and Implementation of the Lightweight Object Model Supporting Distributed Trader)

  • 진명숙;송병권
    • 한국정보처리학회논문지
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    • 제7권4호
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    • pp.1050-1061
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    • 2000
  • This paper presents a new object model, LOM(Lightweight Object Model) and an implementation method for the distributed trader in heterogeneous distributed computing environment including mobile network. Trader is third party object that enables clients to find suitable servers, which provide the most appropriate services to client in distributed environment including dynamic reconfiguration of services and servers. Trading service requires simpler and more specific object model than genetic object models which provide richer multimedia data types and semantic characteristics with complex data structures. LOM supports a new reference attribute type instead of the relationship, inheritance and composite attribute types of the general object oriented models and so LOM has simple data structures. Also in LOM, the modelling step includes specifying of the information about users and the access right to objects for security in the mobile environment and development of the distributed storage for trading service. Also, we propose and implementation method of the distributed trader, which integrates the LOM-information object model and the OMG (object Management Group) computational object model.

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ebXML 등록저장소를 이용한 이러닝 객체 메타데이터의 표현과 관리 (Representation and Management of e-Learning Object Metadata Using ebXML)

  • 김형도
    • 한국콘텐츠학회논문지
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    • 제6권11호
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    • pp.249-259
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    • 2006
  • 이러닝 자원에 대한 재사용 과정을 편리하게 하기 위해서는 표준을 준수하는 메타데이터를 사용하여 이러닝 객체를 적정하게 기술하고 분류하는 작업이 필수적으로 요구된다. 이러한 메타데이터는 이러닝 객체의 재사용에 있어서 중복된 노력을 최소화하고 의미를 상호 이해할 수 있도록 등록저장소에 공개되는 것이 바람직하다. 본 논문은 이러닝 객체에 관한 메타데이터를 생성하고, 저장하고, 발견하며, 추출하는데 있어서 국제 표준인 ebXML(Electronic Business using extensible Markup Language) 등록저장소를 이용하는 방안을 제시한다. 국제적으로 광범위하게 채택되고 있는 IEEE LOM 표준을 준수하여 작성된 이러닝 객체 메타데이터를 ebXML 등록저장소에서 표현하고 관리할 수 있도록, LOM과 ebXML 정보모델간의 변환 체계를 제시하고, 이를 바탕으로 ebRR4LOM이라고 하는 이러닝 등록저장소 프로토 타입을 개발하여 이러한 등록저장소의 유용함을 설명한다.

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관절 가동범위 제한을 동반한 급성 요추부 염좌 환자에 요부사반법(腰部斜搬法)과 한방치료를 병행한 치험 3례 (Three Clinical Cases on Acute Lumbar Sprain Patients with Limited Range of Motion by Chuna Treatment (Saban-Method Technique) and Oriental Medical Treatments)

  • 이경무;안희빈;임상훈;김순중;정수현
    • 한방재활의학과학회지
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    • 제19권4호
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    • pp.189-202
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    • 2009
  • Objectives : This study was performed to evaluate the effects of Chuna treatment (Saban-method technique) on acute lumbar sprain patients with limited range of motion(LOM). Methods : Three patients suffered from acute lumbar sprain with LOM, were treated with Chuna therapy(Saban-method technique), acupuncture, herbal medicine, physical therapy and measured by VAS(Visual Analogue Scale) and ODI(Oswestry Disability Index). Results : After Chuna treatment and oriental medical treatments, we found out a recovery from three patients suffering from acute low back pain with LOM. Conclusions : Through this study, we suggest that Chuna treatment(Saban-method technique) and oriental medical treatments was effective to cure acute lumbar sprain patient with LOM.

ARENA를 활용한 3D 프린팅 기술 기반 거푸집 공사의 생산성 분석 시뮬레이션 모델 개발 (Development of Productivity Analysis Simulation Model for Formwork Based on 3D Printing Technology Using ARENA)

  • 안희재;이창수;김하림;김태훈;조훈희;강경인
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2021년도 가을 학술논문 발표대회
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    • pp.188-189
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    • 2021
  • The technology of manufacturing freeform molds with S-LOM based 3D printer has advantages in the production period and the curvature range. However, there is no any support tool about productivity analysis of S-LOM technology because S-LOM technology is early-stage technology. There can be problems about increase of construction time and cost without any decision support tool like productivity analysis models etc. Therefore, in this study, the productivity analysis simulation model for freeform formwork based on S-LOM technology was developed using ARENA software. The process and logic of manufacturing freeform molds can be easily visualized in this model. Futhermore, the resource like labor, equipment and material can be easily optimized with this model. As a result, it can contribute to preventing the increase of construction time and cost in formwork with further productivity analysis.

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전방 십자 인대 수술 후 합병된 슬관절 강직 - 원인분석 및 치료 - (Stiff Knee Following Anterior Cruciate Ligament Reconstruction - Cause Analysis and Treatment -)

  • 최남용;이인주;최문구;고해석;김승기;박성진;한석구;강영목
    • 대한관절경학회지
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    • 제2권1호
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    • pp.72-76
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    • 1998
  • Between March 1992 and December 1995 at St. Paul's, Holy Family, St. Vincent and Eui Jung Bu St. Mary Hospitals Catholic University, two hundred and eighty patients underwent arthroscopic anterior cruciate ligament(ACL) reconstruction using central one-third bone-patellar tendon-bone autograft. Nine of these patients had limitation of motion(LOM) defined as a knee flexion contracture greater than 10o or less than 125o of passive knee flexion. This study analyzes the causes of LOM after ACL reconstruction as well as the results after passive manipulation or arthroscopic adhesiolysis under anesthesia for LOM. The results are as follows: 1. Out of nine patients, initially three had isolated ACL injuries and six had combined injuries. Seven of nine cases were perfomed by ACL reconstruction within four weeks and two were performed after four weeks following injury. 2. Treatment for LOM after ACL reconstruction was done after 5.5 months on average. 3. Arthroscopic adhesiolysis was done in 5 cases. There were fibrous adhesions at suprapatellar pouch and femoral intercondylar notch in all cases, respectively, infrapatellar fat pad in 3 cases and medial para patellar gutter in 2 cases. Two patients had a fibrous nodule, "cyclops" lesion, which formed anterior to the ACL graft. 4. Range of motion and Lysholm knee score were much improved following passive manipulation or arthroscopic adhesiolysis under anesthesia for LOM.

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분산 전원의 고립 운전 검출 기법 개발 (Development of a Loss of Mains Detection Method for Distributed Resources)

  • 장성일;김광호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 춘계학술대회 논문집 전력기술부문
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    • pp.42-45
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    • 2001
  • The islanding protection for distributed resources (DR) becomes an important and emerging issue in power system protection since the distributed generator installations are rapidly increasing and most of the installed systems are interconnected with distribution network. In order to avoid the negative impacts on distributed network resulting from islanding operations of DR, it is necessary to detect the loss of mains (LOM) effectively. This paper presents a new LOM detection method using the rate of change in total harmonic distortion (THD) of current. The proposed method effectively detects LOM of the DR unit operating in parallel with the distribution network. We also verified the efficiency of the proposed method using the radial distribution network of IEEE 34 bus model.

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