• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2003년도 학술대회지
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• pp.410-413
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• 2003

건설시장에서 경쟁력을 강화하고 국제정책에 대응하기 위하여 설계업체와 시공업체의 협력을 장려하는 설계시공 일관입찰방식이 대두되었다. 설계시공일괄입찰방식은 공기단축, 사업비 절약, 품질 향상을 위한 전도 유망한 입찰방식이지만 국내 건설산업에서는 제도의 미비, 관계자들의 경험 및 인식부족 등으로 이러한 장점을 살리지 못하고 있다. 이에 따라 본 연구에서는 국내 공공공사 설계시공일괄입찰방식에서의 문제점을 사업비, 품질, 사업기간의 측면에서 분석하여 개선방안을 제안하고자 한다.

• 한국건설관리학회논문집
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• 제6권4호
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• pp.91-100
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• 2005

건설 전체 프로세스를 하나의 주체가 단일 책임하에 수행하는 일괄입찰방식은 설계와 시공의 연계로 인한 기술력확보, 공기단축, 사업비절감, 품질확보 등의 예상효과로 인해 적용이 확대되리라 예상되는 발주방식의 하나이다. 한편, 국내 일괄입찰방식의 낙찰자 결정방법은 일괄입찰방식으로 수행되는 모든 프로젝트에 동일한 배점기준을 적용하도록 되어 있어, 일괄사업자 선정시 발주자의 목적과 프로젝트의 특성을 반영하기 어려운 것이 현실이다. 이에 본 연구에서는 일괄사업자 선정에 있어서 발주자의 목적과 프로젝트의 특성을 반영할 수 있는 일괄입찰방식의 적격심사 분야별 배점 결정모델을 제안함으로써, 발주자가 당해 프로젝트에 최적인 일괄사업자를 합리적으로 선정하는 것을 돕고자 하였다.

• 한국디지털건축인테리어학회논문집
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• 제8권2호
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• pp.65-72
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• 2008

Therefore about the city research the research will be necessary from historical time. Are not adapted to a finally new situation the functions atrophy and they change, the different city function creating, they do. Specially, the time according to becoming, becomes the axial oneself more city intensive painter, or, in the city which extends the territory, compares the process which is special historically and the change which change etc. is various is rough (Japanese colonial time) with the atrophy which illustrates shows From the research which sees consequently (1) The background which the central area of the city comes to build and tries to analyze the features which changes from the cities and social viewpoints. And (2) Tries to investigate the city system which comes to make from the process which is special is a Japanese colonial time, Also (3) About movement of the process which the city central area which happens from that place comes to build and the city central area searches. With being like that, Space Syntax where uses from the research which sees makes the result which leads with objective the ground and the reporter comparison to analyze with social causes together does.

• Journal of Construction Engineering and Project Management
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• 제6권2호
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• pp.16-23
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• 2016

The use of inappropriate procurement methods to deliver construction projects has long been acknowledged as a major source of poor project performance and is particularly problematic for the Libyan Construction Industry. Poor procurement method selection has been recognised as a major contributory factor to frequent time and cost overruns. This paper offers a way of selecting specific procurement methods to maximize successful project performance. The methodology involves an intensive review of relevant literature, followed by a semi-structured questionnaire survey. The key findings of the study reveal that 11 out of its 12 common selection criteria exhibit a significant contribution to one or more project performance criteria (time, cost and quality). Project clients should therefore prioritise these criteria when selecting a design-bid-build method. Knowledge of the criteria that contribute positively to project performance will also enable clients to work out, prior to and during construction, the best measures and provisions for successful project outcomes.

• 한국정밀공학회지
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• 제16권11호
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• pp.139-147
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• 1999

Rapid Prototyping has made a drastic change in all industries which needs to reduce the time for the development of new products. Orientation and packing in rapid prototyping is considered as the most important factors to maximize the utilization of space in the build chamber and reduce build time. However, the decision of these parameter is mainly dependant on the operators's experience. This paper presents the methodology to find the optimal build layout considering an orientation and packing of multiple parts in SLS processing. Each part is represented as a voxel structure to deal with the inefficiency in a bounding box approach. Test results show that the adapted BL algorithm with a genetic algorithm(GA) can be applicable to a real industry.

• 한국CDE학회논문집
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• 제11권3호
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• pp.223-233
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• 2006

Layered manufacturing(LM) is emerging as a new technology that enables the fabrication of three dimensional heterogeneous objects such as Multi-materials and Functionally Gradient Materials (FGMs). Among various types of heterogeneous objects, more attention has recently paid on the fabrication of FGMs because of their potentials in engineering applications. The necessary steps for LM fabrication of FGMs include representation and process planning of material information inside an FGM. This paper introduces a new process planning algorithm that takes into account the processing of material information. The detailed tasks are discretization (i.e., decomposition-based approximation of volume fraction), orientation (build direction selection), and adaptive slicing of heterogeneous objects. In particular, this paper focuses on the discretization process that converts all of the material information inside an FGM into material features like geometric features. It is thus possible to choose an optimal build direction among various pre-selected ones by approximately estimating build time. This is because total build time depends on the complexity of features. This discretization process also allows adaptive slicing of heterogeneous objects to minimize surface finish and material composition error. In addition, tool path planning can be simplified into fill pattern generation. Specific examples are shown to illustrate the overall procedure.

• 한국정밀공학회지
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• 제15권2호
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• pp.154-161
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• 1998

Prototypes of a design are always needed for the purpose of visualization and evaluation in the aspect of manufacturability functionality, and aesthetic appearance. Since the prototyping process requires a significant amount of cost and time, various rapid prototyping processes are recently being introduced in the process. However, it is usually necessary for a part built up by a rapid prototyping system to be refined by a post-processing process, in which the stair steps on the surfaces, the support structures (if they exist), and the unprocessed material are eliminated. This post-processing is usually done manually and is a time-consuming task. Especially, eliminating the trapped volumes, the volume of the unprocessed material entrapped by the solidified portion, is sometimes impossible in some processes. This study provides a designer with a tool to detect the existence and to calculate the quantity of the trapped volumes at the given build-up direction, so that the proper build-up direction is chosen or the part is built by pieces to avoid the problems caused by the trapped volumes in advance. Since the proposed algorithm can efficiently calculate the amount of the trapped volumes at any build-up direction, it has the potential of such application as optimizing the build-up direction to minimize the trapped volumes.

• 정보저장시스템학회:학술대회논문집
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• 정보저장시스템학회 2005년도 추계학술대회 논문집
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• pp.96-102
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• 2005

The tribocharge build-up in the slider disk interface can cause ESD (electrostatic discharge) damage. In turn, ESD can cause severe melting damage to MR or GMR heads. We investigated the tribovoltage/current build-up with smooth and textured disks in HDD, operating at increasing disk accelerations. We found that tribe-voltage/current were generated during pico-slider/disk interaction and those levels were about 0.1 ${\~}$ 0.3 V and 10 ${\~}$ 40 pA, respectively. Tribovoltage/current were abruptly increased and dissipated within the acceleration time in the case of textured disk but in the case of smooth disk tribovoltage was continuously increased until the end of uniform velocity region and the tribocurrent did not dissipate within the acceleration time. In the case of textured dist tribovoltage/current was reduced with increasing disk acceleration, but in the case of smooth disk it was increased.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 춘계학술대회 논문집
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• pp.552-558
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• 1995

Stereolithography is a process used to rapidly produce polymer components directly from a computer-representation of the part. There are several considerations to be made for the efficient use of te process. Especially, the build-up orientation of part critically affect to the part accuracy, total build time and the volume of support structures. Te purpose of this study is to determine the optimal build-up part orientation for the SLA process with improving part accuracy, minimizing total build time, and the volume of supprot structures. The first factor is related to the area of surfaces which have staircase protrusions after solidification, the second factor is related to the total number of layers, and the third factor is related to the area of the surfaces which need to be supported with support structures. An algorithm is developed to calculate the staircase area with quantifying the process planning errors that the volume of materials is supposed to be removed or added to the part, and the optimal layer thickness for the SLA system whichcan hadle the variable layer thickness in different orientations achieved by rotating the given part to the specified finite directions. So the optimal part orientation is determined based on the user's selections of primary criterion and the optimal thickness of layers is calculated at any part orientations.

• International Journal of Precision Engineering and Manufacturing
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• 제4권4호
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• pp.51-56
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• 2003

Generally, the build-up printed circuit board manufactured by a sequential process involving etching, plating, drilling, etc, which requires many types of equipments and long lead time. Etching process is suitable for mass production, however, it is not adequate for manufacturing a prototype in the development stage. In this study, we introduce a screen printing technology for prototyping a build-up printed circuit board. As for the material, photo/thermal curable resin and conductive paste are used for the formation of dielectric and conductor. The build-up structure is made by subsequent processes such as formation of a liquid resin thin layer, solidification by a UV/IR light, and via hole filling with a conductive paste. By use of photo curable resin, productivity is greatly enhanced compared with thermal curable resin. Finally, the basic concept and the possibility of build-up printed circuit board prototyping are proposed in comparison with the conventional process.