• 제목/요약/키워드: Reduction Techniques

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VE 대상선정을 위한 평가항목의 가중치결정방법에 관한 연구 (A Study on the Subject Selection of VE Using Decision Weights Techniques)

  • 윤동진;신병윤;정용식;이상범
    • 한국건축시공학회지
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    • 제5권3호
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    • pp.83-90
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    • 2005
  • Was used at step space-time mainly after VE technique sponsors in domestic in the 1960s but have been expanded to design step recently. Possibility of value elevation or cost reduction must choose member that is effectively for active and effective application of VE technique. In this study, when enforce design VE examining for weight decision corrosion protection been using in weight grant composition estimation technique, target choice process wishes to suggest formality and method that can be achieved effectively Main conclusion of this study sorts valuation items step by step for weight appropriation of valuation basis and give point on article of high position point after expert which employer is included estimates article by low rank step and this presented high position method that do union item by item and establishes by item weight. Did these techniques for giving weights so that importance for weight appropriation developed estimation program, and data save of target estimation standard and target estimation standard is possible using straight sit.

VE 대상선정을 위한 평가항목의 가중치 결정방법에 관한 연구 (A Study on the Subject Selection of VE Using Decision Weights Techniques)

  • 유형한;배수용;황재우;윤동진;이상범
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2005년도 춘계 학술기술논문발표대회 논문집
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    • pp.149-155
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    • 2005
  • Was used at step space-time mainly after VE technique sponsors in domestic in the 1960s but have been expanded to design step recently. Possibility of value elevation or cost reduction must choose member that is effectively for active and effective application of VE technique. In this study, when enforce design VE examining for weight decision corrosion protection been using in weight grant composition estimation technique, target choice process wishes to suggest formality and method that can be achieved effectively. Main conclusion of this study sorts valuation items step by step for weight appropriation of valuation basis and give point on article of high position point after expert which employer is included estimates article by low rank step and this presented high position method that do union itembyitemandestablishesbyitemweight. Did these techniques for giving weights so that importance for weight appropriation developed estimation program, and data save of target estimation standard and target estimation standard is possible using straight sit.

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삼차원 자기공명영상법의 뇌 구조 영상을 위한 최적화 연구: 센스인자 변화에 따른 신호변화 평가 (Optimizations of 3D MRI Techniques in Brain by Evaluating SENSE Factors)

  • 박명환;이진완;이강원;류창우;장건호
    • Investigative Magnetic Resonance Imaging
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    • 제13권2호
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    • pp.161-170
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    • 2009
  • 목적 : 평행영상(Parallel imaging)기법의 개발로 긴 촬영시간 때문에 종종 사용되지 못하던 삼차원 영상기법이 최근 들어 환자 병을 진단하는데 새로이 사용되고 있다. 이 연구의 목적은 최근에 뇌 영상에서 개발되어 이용되고 있는 삼차원 자기공명영상을 사람의 뇌에서 짧은 시간 내에 얻을 수 있도록 2차원 평행영상 기법을 사용한 최적화 방법을 연구하는데 있다. 대상 및 방법 : 검사 장비는 3.0T 자기공명영상장치를 이용하였으며 8-채널 SENSE(sensitivity encoding) 머리 코일을 이용하였다. 팬텀 및 3명의 사람 머리에서 영상을 얻었다. 세 가지의 삼차원 영상법인 3D T1WI, 3D T2WI 및 3D FLAIR 영상 방법에 대하여 평행인자(SENSE factor)의 변화에 따른 팬텀 영상을 얻었다. 각각의 영상법에서 영상획득에 적당한 SENSE 인자를 찾기 위해 Phase encoding 방향과 Slice encoding 방향을 조합한 SENSE 인자를 변화시키면서 영상을 얻었다. 영상분석을 위하여 특정영역(ROI)를 설정한 후에 신호대 잡음비 (Signal-to-noise ratio, SNR), 감소분율(Percent Signal Reduction Rate, %R), 대조도(contrast-to-noise ratio, CNR)를 계산하였다. 결과 : 팬텀을 이용한 SENSE 인자 변화에 따른 SNR 및 %R 값의 변화 결과 3D T1WI 방법에서 SENSE 인자를 사용한 것들 중에서 SENSE 인자를 총 3인 경우 약 0.2%의 신호 감소가 나타났고 영상시간은 5분 이내였다. 3D T2WI 방법의 경우 SENSE 인자를 사용한 것들 중에서 SENSE 인자를 총 3인 경우에 약 1.0% 신호 감소가 나타났고 영상 시간은 약 5분 이내였다. 3D FLAIR 방법의 경우 SENSE 인자를 사용한 것들 중에서 SENSE 인자를 4를 사용한 경우에 약 0.2% 신호 감소가 나타났고 영상시간은 약 6분이었다. 사람을 대상으로 할 경우 3D T1W 및 3D T2W영상에서 SNR 및 CNR은 SENSE 인자를 3으로 한 경우에서 SENSE 인자를 4로 한 경우 보다 높게 나타났다. 3D FALIR 영상의 경우 CNR은 SENSE 4에서는 SENSE 3에 비하여 낮았다. 결론 : 본 연구에서는 3가지 3차원 영상법을 실제 임상적용이 가능한 시간 영역에서 SENSE 인자를 변화 시키면서 치적의 영상을 얻도록 하는 연구를 실시한 결과 SNR 감소를 최소화 하면서 영상획득 시간을 약 5분에서 6분 정도 소요되는 2차원 SENSE 인자를 찾았다. 이를 뇌 영상에 적용하였을 경우 SENSE 인자를 적용하지 않은 경우와 비교하면 신호 감소는 최소화 하면서 영상의 질은 큰 영향을 주지 않은 것으로 나타났다. 3D T1W및 3D T2W는 SENSE 인자를 3으로 3D FLAIR인자는 SENSE 인자를 4로 하는 것이 환자를 대상으로 한 뇌 영상에 적합하다고 생각된다. 앞으로는 이들 영상법이 뇌 영상뿐만 아니라 다른 영역의 영상에 적용을 위한 최적화가 필요하다고 생각된다.

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Adjuvant Radiotherapy after Breast Conserving Treatment for Breast Cancer:A Dosimetric Comparison between Volumetric Modulated Arc Therapy and Intensity Modulated Radiotherapy

  • Liu, Zhe-Ming;Ge, Xiao-Lin;Chen, Jia-Yan;Wang, Pei-Pei;Zhang, Chi;Yang, Xi;Zhu, Hong-Cheng;Liu, Jia;Qin, Qin;Xu, Li-Ping;Lu, Jing;Zhan, Liang-Liang;Cheng, Hong-Yan;Sun, Xin-Chen
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권8호
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    • pp.3257-3265
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    • 2015
  • Background: Radiotherapy is an important treatment of choice for breast cancer patients after breast-conserving surgery, and we compare the feasibility of using dual arc volumetric modulated arc therapy (VMAT2), single arc volumetric modulated arc therapy (VMAT1) and Multi-beam Intensity Modulated Radiotherapy (M-IMRT) on patients after breast-conserving surgery. Materials and Methods: Thirty patients with breast cancer (half right-sided and half left-sided) treated by conservative lumpectomy and requiring whole breast radiotherapy with tumor bed boost were planned with three different radiotherapy techniques: 1) VMAT1; 2) VMAT2; 3) M-IMRT. The distributions for the planning target volume (PTV) and organs at risk (OARs) were compared. Dosimetries for all the techniques were compared. Results: All three techniques satisfied the dose constraint well. VMAT2 showed no obvious difference in the homogeneity index (HI) and conformity index (CI) of the PTV with respect to M-IMRT and VMAT1. VMAT2 clearly improved the treatment efficiency and can also decrease the mean dose and V5Gy of the contralateral lung. The mean dose and maximum dose of the spinal cord and contralateral breast were lower for VMAT2 than the other two techniques. The very low dose distribution (V1Gy) of the contralateral breast also showed great reduction in VMAT2 compared with the other two techniques. For the ipsilateral lung of right-sided breast cancer, the mean dose was decreased significantly in VMAT2 compared with VMAT1 and M-IMRT. The V20Gy and V30Gy of the ipsilateral lung of the left-sided breast cancer for VMAT2 showed obvious reduction compared with the other two techniques. The heart statistics of VMAT2 also decreased considerably compared to VMAT1 and M-IMRT. Conclusions: Compared to the other two techniques, the dual arc volumetric modulated arc therapy technique reduced radiation dose exposure to the organs at risk and maintained a reasonable target dose distribution.

시스템엔지니어링 기법 적용에 따른 경량전철 전기시스템의 생명주기비용 절감에 관한 연구 (A study on the Life Cycle Cost reduction of the LRT's power systems based on the advanced Systems Engineering)

  • 최원찬;배준호;허재훈;주지영
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 춘계학술대회 논문집
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    • pp.1434-1439
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    • 2011
  • The purpose of this study is based on the optimize the system life cycle cost apply to the advanced systems engineering techniques consideration thought to the system life cycle for the power system which is the one of the major component of the light rail transit system. Generally, the systems engineering techniques apply to the LRT's power systems are not optimize the whole life cycle cost of the power systems because systems engineering management activities are concentrate in performing the key-technology oriented at the construction stage of the dedicated power systems for light rail transit. Through this study, All the stakeholders can be utilize a this advanced systems engineering techniques which is fully considered the life cycle cost through the considering in whole system life cycle (such as concept, design, operation, maintenance and dispose stage as well as construction stage) and adopted by KSX ISO/IEC 15288 system life cycle processes.

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Validation of Efficient Welding Technique to Reduce Welding Displacements of Ships using the Elastic Finite Element Method

  • Woo, Donghan
    • 해양환경안전학회지
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    • 제26권3호
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    • pp.254-261
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    • 2020
  • Welding is the most convenient method for fabricating steel materials to build ships and of shore structures. However, welding using high heat processes inevitably produces welding displacements on welded structures. To mitigate these, heavy industries introduce various welding techniques such as back-step welding and skip-step welding. These techniques effect on the change of the distribution of high heat on welded structures, leading to a reduction of welding displacements. In the present study, various cases using different and newly introduced welding techniques are numerically simulated to ascertain the most efficient technique to minimize welding displacements. A numerical simulation using a finite element method based on the inherent strain, interface element and multi-point constraint function is introduced herein. Based on several simulation results, the optimal welding technique for minimizing welding displacements to build a general ship grillage structure is finally proposed.

우리나라 친환경 농업의 현황과 발전방향 (Technical Development and Direction of Sustainable Agriculture in Korea)

  • 박무언
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2001년도 추계 학술대회지
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    • pp.3-33
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    • 2001
  • A review on the technical development and agricultural policy direction for sustainable agriculture has been made to clarify the present conditions of agricultural environment for food production and natural resource conservation and to study prospects and solutions successfully to achieve food safety and environment conservation as the 21st agricultural paradigm. Although great improvement of environmentally sound and resource-conserving techniques, sustainability of Korean agriculture has been damaged by quantitative reduction and quality deterioration of agricultural land resources, insufficient implementation of low-input and organic matter recycling techniques and also improper cropping system. It is concluded that goal of sustainable agriculture can be successfully achieved by further improvement of environmentally friendly techniques, and stronger escalation of national implementation programmes with more financial supports including direct payments for sustainability of agriculture under systematical support and cooperation of AKS (agricultural knowledge system).

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제철용 고로의 유한요소해석 (Finite Element Analysis for Iron-Making Furnace)

  • 이만승;백점기;이제명
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2004년도 가을 학술발표회 논문집
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    • pp.245-253
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    • 2004
  • There has been recent demand for extending the life of age-degraded structures and equipment by such techniques as diagnosis, maintenance, safety assessment, and estimating residual life on iron-making plants and hydraulic, thermal, and nuclear power plants. These techniques take into account comprehensive scenarios that may cause malfunction and structural damage and allow an assessment of risk based on the likely scenarios. In particular the safety assessment and residual life estimation of age-degraded ships and equipment facilities require consideration of various factors such as mechanical and thermal stresses, corrosion, hardness, load variation due to changes of operating condition, crack generation and strength reduction of material by fatigue. In this study, a detail thermal stress analysis, one of useful techniques of safety assessment and maintenance, is performed on a blast furnace by using general FEM code (MSC/NASTRAN).

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두 가지 동적 진동실험을 통한 Carbon-epoxy와 Graphite-Epoxy복합재료의 동적 탄성계수 측정 (Experimental Determinations of Elastic Constants Composite Materials, Carbon-epoxy and Graphite-epoxy, Using Two Dynamic Vibratory Techniques)

  • 이동환;박세만;박명균
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 추계학술대회논문집A
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    • pp.596-602
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    • 2001
  • Structures in current use are required of weight reduction and strength in many instances. This naturally necessitates frequent applications of composite materials in many areas. Elastic constants are one of key parameters in determining design guidelines for the specific applications of particular materials. In this research two vibratory techniques (acoustic resonance method and impulse technique)are utilized to evaluate elastic constants. Both techniques are suitable for the measurements of dynamic elastic constants. The Impulse technique provides a quick method for the measurement while the acoustic resonance method produces the values of elastic constants which agree better with theoretical values.

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에너지 부하 감소를 위한 인텔리전트 외피 디자인의 분류 및 표현특성에 관한 연구 (A Study on Classifications and Expression Characteristics of Intelligent Skin Design for Reduction of Energy Load)

  • 서원덕
    • 한국주거학회논문집
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    • 제19권5호
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    • pp.67-75
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    • 2008
  • The Progress and development of technology occurring since the 20th century has improved the quality of life of most people. However, serious energy problems have arisen as a result of this lifestyle of convenience and prosperity. These problems have already stared to threaten the very survival of human beings. Architecture and energy are no longer separate concepts. They are now considered as coexisting subject areas. The mutual relevance of energy, technology and architecture is expected to be more emphasized in the future. This study is concerned with the skin design of intelligent housing, which defines the external and infernal boundary. Applicable design techniques are suggested. The purpose of his study is to classify intelligent skin technologies and applications, and to grasp the design characteristics, advantages and disadvantages, as well as design techniques of each items related to Housing. This study will also suggest application techniques that can be used as basic data for determining an appropriate skin type when designing single buildings.