• Proceedings of the Korea Concrete Institute Conference
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• 1995.10a
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• pp.198-203
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• 1995

The objective of this study is to provide the information on the techniques of manufacturing and experiment in small scale modeling of precast concrete(P.C.)large panel structures. The adopted scale was 1/5th 4types of experiments were performed : material tests for model concrete and model reinforcement, compressive test of horizontal joint, shear test of vertical joint and cyclic static test of 2-story subassemblage structure. Based on the experimental results, the following conclusions are drawn: (1)Model concrete may have in general larger compressive strength than expected. (2) Model reinforcement can show less ductility if the annealing processes were performed without using vaccuum tube. (3) Failure modes of horizontal and vertical joints were almost same for both prototype and model. But the strength of model appears to be higher than required by similitude law. (4)Hysteretic behavior of 1/5 scale subassemblage model can be made quite similar to prototype's if the ductility of model reinforcement and compressive strength of model concrete could be representative of those of prototype.

• Journal of Chest Surgery
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• v.37 no.2
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• pp.188-192
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• 2004

Treatment of huge chronic tuberculous empyema with cardiopulmonary dysfunction. Drainage of empyemal space by closed thoracostomy in chronic tuberculous empyema is generally contraindicated because of the possibility of empyema necessitatis and ascending infection. But in case that serious cardiopulmonary dysfunction is present, drainage of empyema and decompression is necessary. We experienced a case in which chronic tuberculous empyema was big enough to cause mediastinal shifting and cardiopulmonary failure. Immediate drainage of pleural cavity with tube thoracostomy was performed. Afterward, pleuropneumonectomy was done following cyclic irrigation for one month. The patient had successful postoperative course without any evidence of complication or relapse of infection.

• Journal of the Korean Society of Safety
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• v.12 no.1
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• pp.29-36
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• 1997

Precision electronic equipments for outdoor use are composed of sophisticated microcircuits that are extremely vulnerable to lightning-caused voltage spike. This transient voltage spike may cause upset, latent failure or Interference on electronic equipments. In order to develop efficient lightning protection measures on AC power lines of a road traffic controller as a electronic equipment for outdoor use, experimental surge immunity tests were conducted according to IEC standard 801-5. The combination of gas tube arrester and metal-oxide varistor was installed at the input of AC power lines and the silicon avalanche suppressor installed at the output of DC power supply for the lightning protection measures.

• Journal of Chest Surgery
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• v.22 no.6
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• pp.1044-1048
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• 1989

In this study, 26 cases of bilateral spontaneous pneumothorax experienced at the department of thoracic and cardiovascular surgery, Chungnam National University Hospital during from 1985 to August 1989 were analyzed retrospectively. The results were as follows; 1. The incidence of bilateral spontaneous pneumothorax was 13.5 % and sex ratio was 7.7:1 with male preponderance. 2. Among the nonsimultaneously occurring cases of bilateral pneumothorax, 12 patients [75 %] were developed at contralateral side within a year. 3. The most patients [65.4%] belonged to the age group between 15 and 25 year-old, and among 57 male patients suffered spontaneous pneumothorax in the same age group, 16 cases[28%] developed bilaterally. 4. The etiologic factors were as follows; blebs or bullae; 65.4 %, tuberculosis; 15.4 %, unknown; 19.2 %. 5. In the method of treatment, 15 patients were treated by closed tube thoracotomy and underwater-seal drainage only, 10 patients were treated by open thoracotomy. One patient died of respiratory failure due to severe destructed lung.

• Journal of Chest Surgery
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• v.21 no.2
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• pp.395-402
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• 1988

Increasing success in the management of patients with severe respiratory failure by mechanical respirators has produced iatrogenic tracheal stenosis. And the surgical management of these lesions have provided a major field for tracheal reconstructive surgery. Recently we have experienced three cases of postintubation tracheal stenosis between December, 1985 and October, 1987 and successfully performed circumferential resection and end to end anastomosis of the trachea. The lesion of the first case which was located in the subcricoid level was resected about 2cm length with cervical incision. And the lesion of the second case located at the cuff site was also resected about 2.5cm length with cervical and median sternotomy incision. Also the lesion of the third case located at the stoma site was resected about 1.8cm length with cervical incision. The postoperative courses were uneventful but there was extubation difficulty in the third case because of stupor mentality and problem of secretion excretion. So we have observed the postoperative course after T-tube insertion.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.345-349
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• 2003

The dynamic behavior of CANDU nuclear fuel channel was analyzed by the use of 3-dimensional finite element method, under the various fault conditions such as a fault in the end fitting support and the removal/migration of the garter spring in the fuel channel, in order to predict the dynamic behavior for a degraded symptoms of CANDU nuclear fuel channel. Moreover, the frequency response analysis for possible fault conditions was also peformed considering the effects of the pressure tube vibration and flow-induced vibration by the coolant flow. From the analysis of the frequency responses, defects in the garter spring have influenced the changes of 2nd and 3rd modes and all the important modes are varied for the failure in the journal bearing in the end fitting body.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.6
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• pp.195-200
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• 2001

Composites have wide applications in aerospace vehicles and automobiles because of the inherent flexibility in their design for improved material properties. Composite tribes in particular, are potential candidates for their use as energy absorbing elements in crashworthiness applications due to their high specific energy absorbing capacity and the stroke efficiency. Their failure mechanism however is highly complicated and rather difficult to analyze. This includes fracture in fibres, in the matrix and in the fibre-matrix interface in tension, compression and shear. The purpose of this study is to investigate the energy absorption characteristics of CFRP(Carbon Fiber Reinforced Plastics) tubes on static and impact tests. Static compression tests have been carried out using the static testing machine and impact tests have been carried out using the vertical crushing testing machine. Interlaminar number affect the energy absorption capability of CFRP tubes. Also, theoretical and experimental have the same value.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.474-479
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• 2005

For the safe operation of an air conditioner, the liquid car η 'over to compressors should be minimized and compressors should be operated in the specified region of suction and discharge pressures recommended by compressor manufactures. In this study, a capillary assisted tandem-type airconditioner was considered. A variable speed outdoor fan was used to control operating points of the system. Test results showed the possibilities to move system operating points to the safe region by controlling the speed of an outdoor fan.

• Steel and Composite Structures
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• v.8 no.4
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• pp.297-312
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• 2008

A concrete filled double skin tubular (called CFDST in abbreviation) member consists of two concentric circular steel tubes and filled concrete between them. Purpose of this study is to investigate their bending characteristics experimentally. The two test parameters of the tubes considered were an inner-to-outer diameter ratio and a thickness-diameter ratio. As a result, their observed failure modes were controlled by tensile cracking or local buckling of the outer tube. Discussion is focused on the confinement effect on the filled concrete due to the both tubes and also the influence of the inner-to-outer diameter ratios on their deformability and load carrying capacity.

• Journal of the Korean Society of Safety
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• v.18 no.4
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• pp.16-22
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• 2003

Generally the rupture of steam generator tubes proceeds from significant plastic deformation before failure. In this study, the burst pressures of damaged steam generator tubes were calculated from the plastic instability analysis with the finite element method. Two wear types, flat and circumferential types were considered. An equation for the burst pressure was proposed by using the strength reduction factor and the Svensson equation. The analysis results were compared with the experiment data from published references and they showed a good agreement with the experiment data.