• International Journal of Fluid Machinery and Systems
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• v.4 no.1
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• pp.133-139
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• 2011

In this paper, Based on Two-dimensional Flow Theory, adopting quasi-orthogonal method and point-by-point integration method to design the impeller of the low specific speed centrifugal pump by code, and using RANS (Reynolds Averaged N-S) Equation with a standard k-${\varepsilon}$ two-equation turbulence model and log-law wall function to solve 3D turbulent flow field in the impeller of the low specific speed pump. An analysis of the influences of the blade profile on velocity distributions, pressure distributions and pump performance and the investigation of the flow regulation pattern in the impeller of the centrifugal pump are presented. And the result shows that this method can be used as a new way in low speed centrifugal pump impeller design.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1003-1005
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• 2000

The switched reluctance drive provides a good adjustable steed characteristics like a D.C series motor. However, because of the torque production mechanism, it also has some disadvantage such as higher torque ripple and fluctuation in speed. To reduce torque ripple and to control speed precisely at low condition current level technique is adopted. The SRM drive with current control of invariable frequency and phase swichting control has good speed regulation characteristics. Digital control system with an 80c196kc micro-controller is used to realize this drive system. Test results show that the control system has the goof ability to achive precise speed control at low speed.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.112-122
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• 2006

Is the high speed train with 300km/h running speed safe from derailment when it meets the mid or small-size earthquakes? In the present step, it is not so easy to judge whether it'll be derailed or not during an earthquake. However, we could elevate the running safety of high speed train as making it slow or even stop. The main objective of this study is to make the domestic running regulation and the re-running manual for high speed train with reference to the standards of France, Japan etc. To do so, numerical analysis and experiment will be performed from the next year. In addition, we'll evaluate possible places of derailment during an earthquake and make a database based on the Geographic Information System to effectively manage them.

• Journal of Power System Engineering
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• v.18 no.4
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• pp.11-16
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• 2014

Although smoke emitted from ships is not included in IMO(International Maritime Organiztion) regulation yet, it is one of the substance what is polluting mainly the air. Especially, its concentration is very high when an engine is started and a load is rapidly changed. This is caused by unburned fuel what is injected more than necessary quantity after combustion period. It is possible to decrease smoke concentration emitted at starting engine by controlling fuel injection quantity, but it is concerned that time to rated speed must be spent. Then a governor what can reduce the smoke concentration without a loss of time to rated speed is needed. We adopted a electro-hydraulic governor what can control dual fuel start limit function and achieved very low level of smoke concentration without greater the loss of time to rated speed.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.980-987
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• 2024

As buildings become increasingly diverse in size and type, a continuous process of generating and processing various information within these structures occurs. This process is being addressed with the advancement of high-speed information and communication technology, which is being extensively applied in buildings. Such changes are institutionalized through the certification of high-speed information and communication buildings. This certification is crucial for ensuring the quality and connectivity of the essential communication infrastructure in modern buildings. Building Information Modeling (BIM) has established itself as an effective tool for the integrated management of design, construction, and operation in architectural projects. This research aims to refine and categorize the evaluation criteria suitable for the building certification based on high-speed information and communication criteria and to explore the applicability of BIM tools based on these criteria. By enhancing the substitution and connection of each library, the functionalities of BIM programs for a comprehensive review of information and communication facilities are expected to be applied in a more utilitarian direction.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1432-1438
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• 2011

This paper presents the simulation of traction power supply system for the evaluation of voltage drop in Kyungbu high speed line. This simulation is performed in circumstance of extended feeding through vicinity substation. Extended feeding should be considered from design of system. Therefore, voltage drop at extended feeding must be accepted against regulation. In this paper, voltage drop is evaluated under condition of extended feeding targeting section from Shinchungju and Pyungtaek S/S.

• Journal of Korean Association for Spatial Structures
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• v.5 no.1 s.15
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• pp.65-71
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• 2005

This research analyzed dynamic responses of the preflex railroad bridge. Vertical deflection and acceleration induced by operating train loads and test train loads were measured. Deflection of bridge by train traveling satisfies deflection limitation regulation (L/800) about the concrete bridge, but compare with UIC standard, vibration acceleration happened fairly greatly. Also test result show that acceleration receives greatly effect about the speed than deflection. It must discuss about vibration acceleration problems for speed elevation hereafter.

• Proceedings of the KSR Conference
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• 1999.05a
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• pp.267-274
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• 1999

This paper is mainly concerned with the development of the ATO(Automatic Train Operation) System. The ATO system is used for automatic or driverless operation of a train using various informations from TCMS, ATC, TWC. In this paper, the general architecture of the ATO system, implementation of ATO application software and the algorithm using servo-controller for automatic train speed restriction/regulation is presented.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1021-1027
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• 2004

This research analyzed dynamic responses of the preflex railroad bridge. Vertical deflection and acceleration induced by operating train loads and test train loads were measured. Deflection of bridge by train traveling satisfies deflection limitation regulation (L/800) about the concrete bridge, but compare with UIC standard, vibration acceleration happened fairly greatly. Also test result show that acceleration receives greatly effect about the speed than deflection. It must discuss about vibration acceleration problems for speed elevation hereafter.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.452-455
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• 2003

Based on a field-oriented model of induction motor, adaptive backstepping approach using neural network(RBFN) is proposed for the control of induction motor in this paper. In order to achieve the speed regulation with the consideration of avoiding singularity and improving power efficiency, rotor angular speed and flux amplitude tracking objectives are formulated. rotor resistance uncertainty is compensated by adaptive backstepping and mechanical lumped uncertainty such as load torque disturbance, inertia moment, friction by RBFN. Simulation is provided to verify the effectiveness of the proposed approach.