• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.433-434
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• 2006

The limited slip differential(LSD) is a device which enables the driving force to be transmitted from one slipping wheel to another wheel in such case that the car is stuck in clay or snow. When the unwanted slipping occurs on one wheel, the LSD temporarily restraints the differential motion to transmit the driving force in the other wheel. So far, many types of LSD were developed such as mechanical lock type, disk clutch type, viscous coupling type, torsion type and multiple clutch type. we designed a new type of the hydraulic LSD which uses the principle of trochoid gear pump.

• Journal of the Korean Regional Science Association
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• v.10 no.1
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• pp.71-88
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• 1994

In Korea large scale land development projects have been initiated, in general, by public sector. Due to the on-going liberalization and deregulation trends, however, the need for the land development by private enterprizes is growing very fast. Nontheless, the present situation including institutional setting is not favorable enough for the private participation. The purpose of this study is to provide necessary strategies for vitalizing private participation in the land development. The main contents of this study are devided into four parts. First, the background logic of the private participation in land development is investigated theoretically through reference review. Second, the present situation especially in terms of institutional aspects in analysed and criticized. Third, similar experiences of foreign countries, such as Japan, Germany, France, England, are reviewed in short. Finally, some measures and strategies for improving the present institutional settings are provided and recommended. These include the simplification of the complicated planning system, alleviation of the restraints against private land development, diversification of land development methods and etc.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.5
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• pp.805-816
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• 2015

In the present study, external restraints imposed normal to the plate during the cooling stage were determined to be effective for reduction of the angular distortion of butt-welded or fillet-welded plate. A welding analysis model under external force during the cooling stage was idealized as a prismatic member subjected to pure bending. The external restraint was represented by vertical force on both sides of the work piece and bending stress forms in the transverse direction. The additional bending stress distribution across the plate thickness was reflected in the improved inherent strain model, and a set of inherent strain charts with different levels of bending stress were newly calculated. From an elastic linear FE analysis using the inherent strain values taken from the chart and comparing them with those from a 3D thermal elasto-plastic FE analysis, welding deformation can be calculated.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10b
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• pp.922-927
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• 1998

Pipe cooling has been popularly used in the mass concreting work to reduce temperature of the structure since it is known to be the easiest way to apply and has been the customary usage. But wrong application of the system results in the harmful effect on the structure by crack formation due to thermal shocks and improper cooling schemes. Thus, this study aims at the suppling of effective cooling methods through parametric study. For this, circulating method, velocity of water supply and circulating duration were selected as critical factors affecting the effectiveness of cooling system. As a results of thermal analysis, it was found that too much thermal gradient in the vicinity of the pipe creates localized radial or circumferential cracks. The duration of circulating cooling may be recommended to be as short as several days which may safely reduce the concrete temperature to below a final stable value. It was also found that pipe cooling is more effective to decrease the degree external restraints than internal one.

• Journal of the Korean Society of Costume
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• v.5
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• pp.13-22
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• 1981

The stone caves in Korea, though they were first influenced by Chinese cave temples, were not made same with their predecessors in style. Nearly all Korean stone caves are the simulated ones built artificially, and they are divided into the following: A. The caves that were made up with several pieces of natural rocks with some wood works done over them to cover the open spaces between the rocks. B. Wood works were added in front of the rock-cut images of Buddha in order to construct the cave. C. The men-made caves Suk-kul-am in Kyung-ju is well-known among the above kind of the caves. In short, Korean stone caves have their distinction in which they were inspired by the Indian and Chinese examples and developed their own styles to meet the specific conditions and restraints of the Korean mountains. The extant Silla cave temples are classified in the following four groups: 1) The type of Shin-sun-sa(神仙寺) at Kyung-ju 2) The type of Ka-heung-ri cave(可興里) at Yong-ju(榮州) 3) The type of Kun-wi cave(軍威) 4) The type of Suk-kul-am(石窟庵) at Kyung-ju

• Structural Engineering and Mechanics
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• v.24 no.6
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• pp.741-764
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• 2006

The time-dependent analysis of prestressed concrete bridges built adopting the incremental launching technique is presented. After summarizing the well known results derived from the elastic analysis, the problem is approached in the visco-elastic domain taking into account the effects consequent to the complex load history affecting the structure. In particular, the effects produced by prestressing applied both in the launching phase and after it and by application of imposed displacements and of delayed restraints during the launching phases are carefully investigated through a refined analytical procedure. The reliability of the proposed algorithm is tested by means of comparisons with reference cases for which exact solutions are known. A case study of general interest is then discussed in detail. This case study demonstrates that a purely elastic approach represents a too crude approximation, which is unable to describe the specific character of the problem.

• Structural Engineering and Mechanics
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• v.39 no.5
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• pp.643-659
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• 2011

The design of box girders requires the determinations the buckling stress of the flange and the webs. Existing design equations available in codes of practice ignore the interactions between the box girder components. The paper illustrates the influence of the geometric interaction on the buckling stress of box girders. Generalized equations are first derived in terms of the web the flange geometric properties. Industrial examples are then presented showing the variation of the flange buckling stress for various stiffening configurations. The influence of the flange/web proportions on the buckling stress of box girder components is also highlighted. It is shown that buckling strength of the flange is largely affected by the restraints imposed by the webs or attached diaphragms. Graphs are presented showing various limiting states of box girders. These graphs are useful to use in practice in order to achieve economical and efficient design of box girders and rationally predict local buckling stress.

• Steel and Composite Structures
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• v.3 no.1
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• pp.1-12
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• 2003

Cantilevers are unique statically determinate structural elements with respect to their mode of overall buckling, in that the tension flange is the critical flange under gravity loading, and is the flange that deflects greatest during overall buckling. While this phenomenon does not complicate the calculation of the lateral buckling load, either theoretically or in structural design codes, it has been shown in previous research that the influence of distortion in the elastic buckling of cantilevers is not the same as that experienced in the elastic buckling of simply supported beams. This paper extends the study of the distortional buckling of cantilevers into the hitherto unconsidered inelastic range of structural response. A finite element method for studying the inelastic bifurcative instability of members whose cross-sections may distort during buckling is described, and the efficacy of the method is demonstrated. It is then used to study the inelastic distortional buckling of hot-rolled I-section cantilevers with two common patterns of residual stresses, and which may be restrained elastically from buckling by other structural elements.

• Journal of the Semiconductor & Display Technology
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• v.11 no.3
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• pp.51-56
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• 2012

In this paper, we propose a telemedicine system based ECG data using a bio-signal meter and a smart device for treating faraway patients. This system is composed of a patch-shaped portable bio-signal meter, patient's smart device application, and doctor's PC software. Using these components, doctors and patients can do telemedicine. First, a patient measures his own ECG signal with a bio-signal meter and send the data to a doctor using a smart device application. Then, the doctor checks the ECG data, and make and send a diagnosis chart to web server. Likewise, doctors and patients can be offered a medical environment without time and space restraints. Applying this system to real medical system can improve the problem of low accessibility and efficiency and also can reduce medical expenses.

• Journal of the Semiconductor & Display Technology
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• v.11 no.3
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• pp.45-50
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• 2012

In this paper, we propose a real-time ECG monitoring system for personal health records. This study aims to provide services that help patients to monitor their own physical condition and manage their own health records consistently, whereas existing medical services are Medical Institute-Centric model. The system is composed of web server, smart phone, and ECG meter, and web page. Without time and space restraints, It provides us with managing personal health records by performing patient's ECG measurement and real-time monitoring. And also Real-time bidirectional communication between smart phone and web page can be performed rapidly by applying the ECG monitoring with WebSocket Technology that follows HTML5 standard. Through this system, It can handle patient in need immediately.