• International Journal of Air-Conditioning and Refrigeration
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• v.9 no.2
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• pp.62-68
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• 2001

It is a serous subject for energy conservation to prevent the energy loss caused by the mixture of heated and cooled air jets in perimeter and interior zone of a building operated with tow kinds of air-conditioning system simultaneously. The purpose of this paper is to clarify the quantitative and qualitative mechanisms of mixing loss and to propose a evaluation method for it. By using the dynamic heat load calculation, heat extraction load of a typical office building in Busan are calculated. According to the results, numerical simulations based on CFD(Computational Fluid Dynamics) were performed in order to evaluate mixing loss in the physical size of HVAC system. Then, the distributions of air temperature and airflow patterns according to the differences of set-point temperature are analyzed to grasp relations how to influence mixing loss.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.433-444
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• 2008

Nowadays, subway station has provided not only transportation but living spaces for everyday activities. Therefore, a variety of facilities have been installed for a safety of citizens such as fire-fighting equipment, platform screen doors and giving high level of benefits such as air-conditioning and heating equipment, escalators, lighting apparatus. In order to operate these facilities appropriately, it is needless to say that electric power supply must be reliable. Many protection relays have been installed to protect electric apparatus and power system, nevertheless it..s study has been insufficient in the concrete. From this paper, through analyzing of protection relay system of electric room operated in line 2 of Seoul metro, we can help to improve stable power supply system of subway station.

• Journal of Korean Neurosurgical Society
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• v.43 no.1
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• pp.48-50
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• 2008

We experienced a case of giant arachnoid granulation misdiagnosed as dural sinus thrombosis. A 66-year-old woman presented with a one month history of progressive occipital headache. Computed tomography angiography and cerebral angiography showed a round filling defect at the transverse sinus which was speculated as a transverse sinus thrombosis. Anticoagulation therapy was performed to prevent worsening of thrombosis for 2 weeks and then a Gadolinium-enhanced magnetic resonance imaging scan was performed. The filling defect lesion at the transverse sinus revealed a non-enhancing granule with central linear enhancement, which was compatible with giant arachnoid granulation. We checked the intrasinus pressure difference across the lesion the through the dural sinus in order to exclude the lesion as the cause of headache. Normal venous pressure with no significant differential pressure across the lesion was noted. Headache was treated with medical therapy.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.315-320
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• 1998

In this work, an automatic software verification method for Nuclear Power Plant (NPP) protection system is developed. This method utilizes Colored Petri net (CPN) for modeling and Prototype Verification system (PVS) for mathematical verification. In order to help flow-through from modeling by CPN to mathematical proof by PVS, a translator has been developed in this work. The combined method has been applied to a protection system function of Wolsong NPP SDS2(Steam Generator Low Level Trip)and found to be promising for further research and applications.

• International Journal of Control, Automation, and Systems
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• v.2 no.3
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• pp.384-389
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• 2004

Recently a method of model reduction for discrete systems has been proposed in the literature based on a new impulse response Gramian. In this method, the system matrix$A_r$ of a reduced model is computed by approximating the reduced-order impulse response Gramian. The remaining matrices $b_r$ and $c_r$ are obtained so that various initial Markov parameters and time-moments of the original system are preserved in the reduced model. In this paper a different approach is presented based on the recursive relationship among the impulse response Gramians.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.311-318
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• 2002

A GIS-based tunnelling risk management system (GIS-TURIMS) has been developed in this study, The developed system uses ArcView 8.2 as a basic platform and the built-in interface (VBA) has been used to perform first-order simplified analyses for prediction of tunnelling-induced ground movements and building damage assessment. The main emphasis in this study was to develop a working framework that can be used in the perspective of tunnelling risk management. The developed system is capable of carrying out computationally intensive analyses for ground movement prediction as well as building/utilities damage assessment with fully taking advantage of the GIS technologies. This paper describes the concept and details of the GIS-TURIMS development and implementation

• Journal of Korean Port Research
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• v.13 no.2
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• pp.289-302
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• 1999

As the size and complexity of network increase Distributed System Management (DSM) will be significant issue within information network in order to increase the high reliability and to improve the flexibility of network management. The OSI management model has several problems. The key problems are that it does not fully address the problem of how to develop communication protocol in support of DSM and how to classify the management connection criteria. In this paper to solve first problem described above this paper propose the connectionless CMIP to accomplish for effectively managing the distributed management managing systems to handle the dynamic informations. To work out second problem we introduce the connection criteria in the hierarchy of management system and finally evaluate the efficiency of a suggested protocol during cooperative negotiation among the managing system.

• KIEE International Transactions on Power Engineering
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• v.4A no.2
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• pp.69-72
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• 2004

Nowadays, one of the serious problems in the KEPCO system is a much higher fault current than the SCC (Short Circuit Capacity) of the circuit breaker. Since superconductivity technology has become more developed, the HTS-FCL (High Temperature Superconductor-Fault Current Limiter) may become an attractive alternative to solving the fault current problem. In order to achieve the best performance, the parameters of HTS-FCL should be designed optimally. Under this setting, this paper presents the optimal design method of parameters for resistive type HTS-FCL using the Monte Carlo technique.

• Spatial Information Research
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• v.9 no.2
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• pp.171-184
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• 2001

The nature of ill-defined planning problems makes expert systems difficult to acquire and represent knowledge for decision making in urban planning processes. In order to resolve these problems, a case-based reasoning method was applied to develop a spatial analysis system for urban planning. A case study was conducted in a residential land use planning process. The result of the study revealed the effectiveness of reasoning by the spatial analysis system and the possibility of its future application. More accumulation of information on other successful cases should be sought to yield better results

• Journal of the Korea Safety Management & Science
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• v.4 no.2
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• pp.113-122
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• 2002

The marketing environment of recent security business has been changed as goods and service have been changed variously. Under this condition, the security corporations have been trying to have good relationship with customers and to have high gains as well. But the management of the customers in the bond marketing is not enough. Then, this paper suggests some methods to promote the CRM at bond brokerage in order to make profits in the security corporation. First, the customers will know the earning rate of the bond that they have and also they can analysis the difference selling the bond and keeping it until the due date. The developed bond management system analyzes customers' preference from questionaire which is responded by customers. It also can make customers actively sell and buy the bond through recommendations corresponding with customers' preference. Moreover, this paper suggests the video conference consulting system for close relationship with corporation and customers. We have tested this bond management system and we expect that this system activates the buying and selling of the bond that non-experts can easily invest bonds and the security corporations can increase profit.