• Proceedings of the Korea Information Processing Society Conference
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• 2003.11b
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• pp.1037-1040
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• 2003

본 논문에서는 LAN 상에서 유휴 PC 들을 연산에 활용하는 PC Cluster 시스템에 대해 연구하였다. 특히, PC 실습실에 있는 PC 들의 유휴시간(Idle time)대를 이용하여 Cluster 연산에 사용함으로써 별도의 전용 클러스터 시스템을 설치하기 위한 하드웨어 및 설치 공간이 필요로 하지 않는다는 장점을 갖는다. PC 실습실의 PC 들은 주간에는 주로 교육 및 실습에 사용되며 오후 6시부터 오전 9시까지의 실습에 사용되지 않는 유휴시간을 CPU-Intensive 한 작업들을 병렬로 수행하는 PC Cluster로 구성하여 저가격의 고성능 시스템을 구축할 수 있다. 그리고 특정 연산을 전담하는 노드들을 지정하고 이 노드들의 연산 결과를 인접한 다른 노드들에게 전달함으로써 연속적인 다음 연산을 적용할 수 있도록 파이프라인(Pipeline) 형태로 구성한다. 파이프라인 형태의 PC Cluster 에서 연산을 겹침(Overlapped)으로서 처리량(Throughput)을 높일 수 있다. LAN으로 연결된 PC 실습실의 PC 들은 인터넷상의 연산 자원들보다 안정되고 신뢰성이 있기 때문에 복잡한 보안 기법을 사용하지 않아도 된다. 또한 연산시간이 유휴시간으로 고정되어 있기 때문에 네트워크의 부하 및 노드의 부하를 고려하는 복잡한 부하균등화 기법이나 스케줄링 기법이 필요로 하지 않는다.

• Journal of the Korean Institute of Gas
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• v.21 no.1
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• pp.27-33
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• 2017

In this study, the stability of trench slope was analysed in summer and winter seasons for the construction of pipelines in permafrost regions. The construction standards of Korea, Russia and UK were compared for obtaining an optimum trench shape for a pipeline of 30 in. diameter. Using the geotechnical properties of soil in Yakutsk (Russia), the stability of trench slope was analysed using Strength Reduction Method (SRM) according to the horizontal slope angle values of $0^{\circ}$, $10^{\circ}$, $20^{\circ}$ and $30^{\circ}$ and vertical slope angle values of $20^{\circ}$, $30^{\circ}$ and $40^{\circ}$. In both seasons, an increase in the slope angle results in a decrease in the factor of safety. The results show that horizontal slope angle of $30^{\circ}$ was not safe in summer season. At the vertical slope angle of $20^{\circ}$, trench side failure was observed, whereas, ground slope failure was observed at the vertical slope angles of $30^{\circ}$ and $40^{\circ}$. Due to the solidification of pore water at temperatures below $0^{\circ}C$, cementation of soil particles take place. Therefore, the trench slope was found to be stable in the winter season at all vertical and horizontal slop angles, except for special load cases and abrupt temperature changes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.5D
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• pp.473-481
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• 2012

Demand of Natural Gas (NG) consumption is continuously increasing by long service life and low environmental impact than other fossil fuels. Because of this reasons, Gas wells exploration and huge LNG plant construction project are being boosted world-widely. Especially, overseas NG pipe-line projects are emerging by considering safe and efficiency at the inter-country sections. At the same time, Korean contractors are being achieved to record-breaking performance at 2011's overseas construction market and 80% of new-record was attained from overseas plant construction projects. Nevertheless, Korean contractors are behind than overseas leading contractors by geographical distance from gas wells and concentrated demand for storage plant. In these reasons, this paper aims to develop the standardized business process model(BPM) for overseas NG pipe-line project at project planning phase to support the project entry. To this aim, first of all, extract the BPM through the broad literature and overseas construction market review and domestic/overseas pipe-line project analysis. Second, Test-bed was performed to confirm of practical applicability by 4 experts. And then 15 experts survey were performed to validate the usability and effectiveness of BPM for overseas NG pipe-line project. Consequently, if Korean contractors are using this BPM with their own know-how and experiences, it will be returned to more reasonable and rational references for decision making in overseas NG pipe-line project.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.4
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• pp.1-9
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• 2018

The development of new technology and process in industrial Plant which builds integrated structures, facilities and systems. Has become a key element for strengthening its competitiveness. Although domestic industrial Plant has demonstrated excellence in technology with a persistent increase in order quantity and orders received, the technology gap between countries has narrowed due to global construction trend. Therefore, it is necessary to develop new technology that could help overcome constraints and limitations of the current one to follow the trend in the age of unlimited competition. This study has focused on assembly technology of Pipe-rack joint connection in an effort to strengthen technological competitiveness in industrial Plant. Through an analysis of earlier studies on Pipe-rack and a coMParative analysis of strengths and weaknesses of current assembly technology of it, a new design plan has been made to improve it efficiently. In doing this, standards for design factors of both structural and performance features have been drawn, and value of stress, strain, moment and rotation has been calculated using finite element analysis. As a result, installation technology of modular type Pipe-rack, which has not been developed in Korea and is differentiated from the current one, has been developed. It is considered that the technology reduces work time and saves cost due to simplified joint connection of steel structure, unlike the current one. Moreover, since it is installed without a welding process in the field, industrial accidents would be reduced, which is likely to have economic competitiveness and satisfy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5763-5768
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• 2015

A relief valve is a mechanical element to keep safety by controlling high pressure. Usually, the high pressure is relieved by using the spring force and letting the fluid to flow from another way out of system. When its normal pressure is reached, the relief valve can return to initial state. The relief valve should be designed for smooth operation and should satisfy the structural safety requirement under operating condition. The commercial software ANSYS/WORKBENCH is utilized for flow and structural analysis. Very high pressure may cause structural problem due to severe stress. The study suggests the design satisfying the structural design requirement

• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.2
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• pp.175-188
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• 2009

When a new tunnel is excavated by the drill and blast method near pre-existing underground structures or tunnels due to the region restricted condition such as urban area, the ground will be relaxed by the excavation. In this case, issues can be created in terms of stability of pre-existing underground structures. One of major factors determining the stability of pre-existing underground structures can be a separation distance between pre-existing underground structures and a newly excavated tunnel. The region of ground relaxation defined by the plastic zone due to new excavation can be varied by separation distance. In this study, in other to estimate an influence of new tunnel excavation in terms of separation distance on the stability of pre-existing large pipelines, two-dimensional scaled model tests using plaster were performed for six models which have a different separation distance, The results show that based on the analysis of induced displacement during tunnel construction, the displacement decreases as the separation distance between large pipeline and new tunnel is increased until the distance is 2.5 times of pipeline diameter. Beyond this point, however, the displacement has become stabilized.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.425-428
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• 2006

Natural gas hydrate has been a major problem for its plugging nature in the pipeline. With the demand of deep-water production, the importance of flow assurance technology, preventing hydrate, asphaltene and wax in the pipeline becomes bigger Kinetic models combined with the flow simulator are being developed to explain the nature of hydrate plug formation in the pipeline. To simulate the hydrate plug formation, each stage including the nucleation, growth and agglomeration should be considered. The hydrate nucleation is known to be stochastic and is believed hard to be predicted. Recent publications showed hydrate growth and agglomeration can be observed rigorously using a particle size analyzer. However properties of the hydrate should be investigated to model the growth and agglomeration. The attractive force between hydrate particles, supposed to be the capillary force, was revealed to be stochastic. Alternative way to model the hydrate agglomeration is to simulate by the discrete element method. Those parameters, particle size distribution, attractive force, and growth rate are embedded into the kinetic model which is combined Into the flow simulator. When compared with the flowloop experimental data, hydrate kinetic model combined into a flow simulator showed good results. With the early results, the hydrate kinetic model is promising but needs more efforts to improve it.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.5809-5818
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• 2013

This study proposes a technology portfolio analysis method for technology outsourcing of pharmaceutical cooperations by applying the concepts of 'Pipeline Soundness' and 'Patent Validity'. This study also applied the developed portfolio analysis method to a 'real world case' of Amgen's acquisition of Onyx Pharmaceuticals to prove the applicability of the method to the real world cases and investigated the validity of the acquisition affair between the two companies. The results of portfolio analysis showed that Amgen's technology portfolio will be improved by acquiring Onyx Pharmaceuticals especially in cancer field which is their main field. So we concluded that Amgen's choice of Onyx pharmaceuticals as a source of technology outsourcing was reasonable. We think that the technology portfolio analysis method developed by this study will be a valuable tool for pharmaceutical cooperations for investigating their current technology status and selecting target companies for technology outsourcing.

• Journal of the Korean Society of Marine Environment & Safety
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• v.2 no.1
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• pp.77-82
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• 1996

Subsea pipelines are exposed to several potential risks of damage due to wave, soil instability and other hazards. Structural failure of the steel pipelines will result in serious consequences such as release of transported hydrocarbons, pollution to the ocean environment and heavy costs due to repair. This paper examines the safety of subsea pipelines with free span which is one of high potential damages. The variation of an allowable length of static free span is examined for different boundary conditions and is given in a curve which is useful for the dsign of the subsea pipeline with a free span.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.1B
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• pp.21-30
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• 2012

Sensor networks are composed of a great number of sensor nodes with constrained battery. Disjoint multipath scheme based flooding method has a merit that efficiently construct multipath in irregular networks, but causes lots of energy consumption in networks. Flooding method is not a suitable technology in wireless sensor networks with constrained battery. We introduce energy-efficient geographic routing scheme considered as an efficient, simple, and scalable routing protocol for wireless sensor networks. The geographic routing scheme on multipath generates a problem with a congestion. So we introduce the concept of multipath pipeline as a congestion avoidance strategy. But multipath pipelines have a big problem on the boundary of holes under irregular networks. We propose a novel disjoint multipath scheme as combined method with geographic routing scheme and hole detouring algorithm on multipath. A novel disjoint multipath scheme constructs disjoint multipath pipelines efficiently for reliability without a collision in irregular wireless sensor networks. Simulation results are provided to validate the claims.