• 한국건축시공학회지
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• 제9권4호
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• pp.75-83
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• 2009

현재 기계굴착공법인 올케이싱, 어스 드릴, 역순환공법이 널리 활용되고 있음에도 불구하고, 시공 현장에서 발생되는 부조화로 인하여 말뚝의 품질이 저하되거나 부실시공이 빈번히 발생되고 있다. 본 연구에서는 이 문제를 줄이는 방법으로 올케이싱, 어스 드릴, 역순환공법을 중심으로 현장 콘크리트타설 말뚝 시공시 발생되는 부조화 종류별로 부조화 발생요인을 현장기술자들을 대상으로 설문조사를 수행 하였다. 그리고 설문분석결과를 토대로 부조화 종류별로 빈번히 발생되는 부조화 요인을 분석함으로서 대응방안을 제시하였다. 본 연구에서 분석된 자료는 향후 건설현장에서 기계굴착공법으로 시공될 때, 부조화를 최소화 할 수 있는 효과적인 자료가 될 것으로 사료된다.

• 한국자동차공학회논문집
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• 제6권5호
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• pp.28-36
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• 1998

In order to establish the hydraulic design process of the torque converter, pump, turbine and stator were designed by reverse design method including one dimensional analysis, angular momentum distribution and forced vortex design. And the significance of evaluation of the circulation flow rate in torus of the torque converter was verified by numerical calculation if the combined blade rows of pump and turbine. It was confirmed that the computational method using interrow mixing model by Park and Cho was reliable to predict the flow-field and performance of the torque converter.

• 태양에너지
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• 제7권2호
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• pp.37-53
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• 1987

This study has been prepared for the purpose of developing the system performance prediction method of natural circulation solar hot water system. The storage tank of the natural circulation solar hot water system equipped with flat-plate solar collector is located at higher elevation than the solar collectors. Therefor, the storage tank temperature distribution formed accordance with configuration of storage tank by flow rate of circulating fluid affect system collection efficiency. In this study measure the storage tank temperature distribution with various experimental system under real sun condition and present the theoretical prediction method of the storage tank temperature. Moreover measure the flow rate not only day-time but also night-time reverse flow rate with die injection visual flow meter. Main conclusion obtain from the present study is as follows; 1) The storage tank temperature distribution above the connecting pipe connection position is the same as that of the fully mixed tank and below the connection position is the same as that of stratified tank. 2) The system performance sensitive to the storage tank temperature distribution. Therefore detailed tank model is necessary. Average storage tank temperature can be calculate 3% and storage tank temperature profile can get less than 10% difference with this model system.

• Nuclear Engineering and Technology
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• 제53권11호
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• pp.3635-3642
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• 2021

Natural circulation systems (NCSs) are extensively applied in nuclear power plants because of their simplicity and inherent safety features. For some passive natural circulation systems in floating nuclear power plants (FNPPs), the ocean is commonly used as the heat sink. Condensation induced water hammer (CIWH) events may appear as the steam directly contacts the subcooled seawater, which seriously threatens the safe operation and integrity of the NCSs. Nevertheless, the research on the formation mechanisms of CIWH is insufficient, especially in NCSs. In this paper, the characteristics of flow rate and fluid temperature are emphatically analyzed. Then the formation types of CIWH are identified by visualization method. The experimental results reveal that due to the different size and formation periods of steam slugs, the flow rate presents continuous and irregular oscillation. The fluid in the horizontal hot pipe section near the water tank is always subcooled due to the reverse flow phenomenon. Moreover, the transition from stratified flow to slug flow can cause CIWH and enhance flow instability. Three types of formation mechanisms of CIWH, including the Kelvin-Helmholtz instability, the interaction of solitary wave and interface wave, and the pressure wave induced by CIWH, are obtained by identifying 67 CIWH events.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.145-156
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• 2009

Large diameter bored pile was selected as the foundation type for Taipei 101. The pile construction method and specific construction procedures were determined based on the results of trial installation and pile load tests. The baseline for foundation design was established using the friction versus depth characteristics of each ground layer obtained from the pile load tests. As the ground profile and depth to the top of rock formation varied significantly on this site, the pile length, bearing capacity and settlement for single pile were analyzed using the information interpreted from adjacent boreholes. The post grouting at pile tip was mandatory for pile construction. Nevertheless, it was treated as a measure reducing the influence of construction uncertainties and providing extra safety for the foundation system.

• Archives of Plastic Surgery
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• 제36권4호
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• pp.445-449
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• 2009

Purpose: A successful surgical treatment for a wide alveolar cleft with bone graft is difficult to achieve due to several factors such as the limitation of gingivoperiosteal flap, the presence of large scar tissues, and the poor blood circulation. To overcome these problems, alveolar distraction osteogenesis using Liou alveolar distraction device was applied. We analyzed the consequences of this surgical treatment. Method: Between 2006 January and 2007 August, we have conducted analysis on the methods and consequences of Liou alveolar distraction osteogenesis for 6 patients. The age of patients was 12 years and 6 months in average. The follow up period was 19 months in average. The Reverse L osteotomy followed by the placement of the Liou alveolar distraction device was performed. After serial distraction, the distractor was removed after 5 months of the process of osteogenesis, and the result was analyzed using the computed tomography and the x-ray films of the alveolar bone and the teeth. Results: The alveolar cleft with 12.5 mm in average width was filled with 8.5 mm of newly formed bone tissue in average width after 5 months of osteogenesis. Among the 6 cases, 5 required the additional bone graft and 1 case only required the gingivoperioplasty. The newly formed bone tissues did not show any signs of bone resorption. However, a considerable degree of teeth displacement was shown. Conclusion: For the alveolar cleft too wide to be reconstructed by a general bone graft, it is strongly recommended to perform the reverse L osteotomy of the cleft side with Liou alveolar distraction device to initiate the alveolar osteogenesis. However, the migrated teeth showed some degree of relapse, thus, the orthodontic treatment is essential following the distraction osteogenesis treatment.

• 대한기계학회논문집A
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• 제26권12호
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• pp.2615-2623
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• 2002

In this paper, a systematic design approach for a three shaft hydromechanical transmission(HMT) system is proposed by considering the power characteristics and speed ratio range. Using network analysis, possible configurations of the 3 shaft HMT are analyzed and it is found that the influence of HSU stroke on the power distribution of the HMT can be investigated by the network analysis. In addition, design methods are presented from the viewpoint of (1) power distribution and (2) speed ratio range. From the power distribution and the speed ratio range, a HMT configuration can be constructed, which minimizes the power circulation and provides the desired speed ranges. Based on the 3 shaft HMT analyses and the proposed design approach, a 3 shaft HMT is designed which provides 4 speeds in forward and 1 speed in reverse while keeping the power circulation less than 150% of the input power. It is expected that the design method suggested in this study can be used in a systematic design of the 3 shaft HMT.

• 약학회지
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• 제44권3호
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• pp.251-256
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• 2000

Sterically stabilized liposomes (SSL) composed of distearoylphosphatidylcholine, cholesterol, dicetylphosphate and distearoylphosphatiodylethanolamine-N-poly(ethyleneglycol) 2000 (DSPE-PEG 2000) were made by reverse phase evaporation method to prolong biological half-life and decrease toxic side effect of drug. Streptozocin (572), a water-soluble antitumor agent with short half-life, was selected as a model drug. The size of SSL was controlled by polycarbonate extrusion to 100 nm which is adequate size for long circulation in plasma. The release rate of drugs from SSL in PBS was evaluated. And the stability of STZ-containing liposomes against drug leakage into rat plasma was evaluated in order to investigate the interaction of liposome and plasma protein. Incorporation of DSPE-PEG 2000 into conventional liposomes significantly decreased the drug leakage into rat plasma.

• Archives of Reconstructive Microsurgery
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• 제17권1호
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• pp.14-18
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• 2008

Purpose: Evaluation of results of free flap as a method of reconstruction in soft tissue defect after wide excision of soft tissue tumor of extremity. Materials and Methods: From 2000 through 2007, 11 patients received free flap surgery for soft tissue defect after wide excision operation for soft tissue tumor of limbs. Four cases were upper extremities and seven were lower extremities. Four subjects were diagnosed as squamous cell carcinoma, three as malignant melanoma, two as synovial sarcoma and one as malignant fibrous histiocytoma and alveolar soft part sarcoma. Donor sites of free flap varied with anterolateral thigh flaps in six cases, latissimus dorsi flaps in four, reverse forearm flap in one. By the method of doppler ultrasound, venous circulation was evaluated for the survival of each flap on the third, fifth and seventh day respectively after the operation. Results: 10 of 11 free flaps were successfully survived. Necrosis of free flaps in 1 cases occurred in case of anterolateral thigh flap. Conclusion: Free flap can be a useful method for reconstruction of soft tissue defect after wide excision of soft tissue sarcoma of extremity.

• 한국실내디자인학회논문집
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• 제16권6호
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• pp.36-46
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• 2007

Regeneration of old buildings is one of the most imperative responses to the 21th century issue of sustainable urban architectural environment. In particular, creative circulation of generation which conversion means highlights the conversion as a new design method. In this study, by examining buildings built over the last decade, the mutual relationship between old elements of existing buildings and new elements of newly required functions was analyzed and types of relationships such as 'alien insertion', 'mediate intervention', 'endogenous expansional enveloping', 'contrastive confliction' and 'over-layering' were defined. In addition, design strategies including the paradoxical curio, fore-grounding and unification were derived from each relationship. Finally, according to the relation type and design strategy, this study suggests several features of conversion design; (1) maximization of symbolism using unfamiliarities - emphasizing futuristic or contextual symbol with intentional contrasts by preserving the work or using contemporary addition; (2) time confusion using neutral space - meeting the need by harmonizing and cooperating existing elements and new elements; (3) mutual emphasizing by individualization - revealing differences between old and new for an aesthetical tension; (4) synchronism by constructional combination - making the one unity of different layers; (5) expansion by enveloping - experience of visual reverse and creation of extra space by roofing above building groups. The reconversion should be continuously researched in the future since conversion is a sustainable design method for the future of architecture.