• Journal of Welding and Joining
• /
• v.17 no.2
• /
• pp.44-52
• /
• 1999

This study deals with spot weld ability of dissimilar aluminum alloy sheets in order to take advantage of its lightweight and strength. The paper also shows the relationship between weld elements(i.e. current, welding time and tip force) and weld quality on the resistance spot weld part of the same and dissimilar Al alloy. The conclusions are: (1) Because of excessive tip force, deep indentation remained at the Al 5182 side which is lower stiffness at the dissimilar Al alloy. (2) Weld quality (i.e. tensile shear strength) of dissimilar Al alloy is superior to that of the same Al 6061 alloy. (3) As long cycles, fatigue life of spot weld specimen on dissimilar Al alloy sheets was better than that of the same Al alloy.

• Tuberculosis and Respiratory Diseases
• /
• v.43 no.1
• /
• pp.14-21
• /
• 1996

Objectives: Although outbreak of MDR Tb has been a recent problem in western countries, it has been a longstanding problem in Korea. The poor outcome of MDR Tb is mainly due to poor compliance, high rate of side reaction of secondary drugs, and limitation in number of available drugs. Thus, to improve the outcome of MDR Tb, it is crucial to make individualized adequate prescription based on the knowledge of the patterns of resistance to each drugs in the community as well as the natural history. The purpose of present study is to evaluate the clinical features of Korean MDR Tb patients including patterns of drug resistance and success rate of treatment which was prescribed according to the sensitivity tests. Methods: Retroscpective analysis of 71 Korean patients with MDR Tb was made. All strains isolated from patients showed resistence to at least two first line drugs. Patients profile, previous treatment history, patterns of drug resistance, outcome of treatment was analysed. Initial treatment regimen was selected according to the previous treatment history and was modified according to the sensitivity reports. The regimen was composed to include at least 4 sensitive drugs when possible. Results: The patients showed resistance to 4.1 drugs on average. 90% of them were resistant to INH and RFP. Among 71 patients, 35 patients(49%) had cavitary lesions in CXR. Treatment outcome was analysed in 55 patients. 35 patients(67%) were improved after treatment and 18 patients(33%) showed treatment failure. 5 patients showed primary resistance. Treatment outcome could be evaluated in 4 of them and all showed improvement after treatment. 14 patients(20%) had to change their regimens due to drug side effects. The most frequent side effect was elevation of liver enzymes(6 patients). Others included dizziness, hyperuricemia, tinnitus, skin rash, GI troubles. More than 50% of side effects developed within 3 months. In repeated drug sensitivity test, the concordance rate of resistance to INH was 100% and RFP 98%. EMB, PZA showed 80% concordance rate. But in the other drugs, the concordances were less than 50%. Operation was done in 5 patient - 1 patients as a adjunctive means of chemotherapy -. In that case, negative conversion of sputum AFB was done. Conclusion: 2/3 patients of multidrug-resistant tuberculosis were improved by appropriate prescription and regular medication suggesting that more aggressive management and monitoring is indicated in multidrug-resistant tuberculosis.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2008.11a
• /
• pp.518-523
• /
• 2008

The modular beam made of steel material is wholly responsible for the load stress of the structure, therefore securing the fire-resistant capacity of the steel beam is absolutely important. The economic efficiency achieved by minimizing the thickness of the fire-resistant board attached, is also essential at the same time. Accordingly, a study of optimization of the thickness and interval of fire-resistant boards shall be conducted side by side. Therefore, in this study we have anticipated fire-resistant capacity by using a general-purpose S/W for finite elements, ABAQUS(6.7.1), in order to propose the configurable conditions that can secure the optimal fire-resisting capacity of modular beam. As a result of this analysis, it was impossible to secure the fire-resistance capacity when directly attaching fire-resistant board(30mm) on the modular board in accordance with KS F 2257-1, and the fire-resistant boards were manufactured in shape of module in consideration of its installation interval rather than direct application.

• Journal of the Korean Society of Safety
• /
• v.29 no.6
• /
• pp.137-143
• /
• 2014

Asbestos is given to a variety of six naturally occurring silicate minerals. These minerals possess high tensile strength, flexibility, resistance to chemical and thermal degradation, and electrical resistance. These minerals have been used for decades in thousands of commercial products, such as insulation and fireproofing materials, automotive brakes, textile products, cement and wallboard materials. When handled, asbestos can separate into microscopic-size particles that remain in the air and are easily inhaled. It is now known that prolonged inhalation of asbestos fibers can cause serious and fatal illnesses including malignant lung cancer, mesothelioma, and asbestosis. Therefore the use of asbestos and asbestos products has dramatically decreased in recent years. Also all constructions including asbestos should be removed under strictly controlled conditions and very tightly implemented health & safety management systems. In this study, the process of the removal work of the asbestos cement slate was analyzed by IDEF-0 modeling and evaluated by 4M risk assessment method. The results show that removal work of the asbestos cement slate was classified five process and eighteen detail process. The risk of safety side the higher than the risk of health side in 4M risk assessment.

• Archives of Plastic Surgery
• /
• v.32 no.4
• /
• pp.496-502
• /
• 2005

This study was performed to compare the effect of external ultrasound assisted PAL(power assisted liposuction) with that of PAL alone. We performed 17 cases of liposuction from January 2003 to June 2003. For comparing both systems, we treated the right side(study group) with external ultrasound assisted PAL and the left side(control group) with PAL alone. To evaluate the difference in results between two groups, we surveyed three objective and four subjective items. Objectives were categorized as "Reduction rate of postoperative swelling", "Efficiency of suction" and "Histologic finding of aspirated fat tissue". Subjectives were also filed as "Degree of postoperative bruising", "Cannula resistance that operator felt", "Degree of postoperative pain" and "Patient's satisfaction". We assessed by questionnaire three times at 1day, 7 days and 30 days after operation. There were statistically significant differences in two of the subjective items; "Degree of postoperative pain at postoperative 1 day" and "Cannula resistance that operator felt". This study concludes that external ultrasound PAL is more effective high mobility of fat tissue and low tension of surrounding tissue. External ultrasound PAL will be more useful in case of large volume liposuction and revision procedures.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.16 no.4
• /
• pp.88-96
• /
• 2008

Effects of the duct inlet guide vane on the flowrate distribution characteristics of the defroster nozzle exit in a defrost duct system were investigated experimentally to design the optimum heating, ventilation and air conditioning (HVAC) system applied in an automotive compartment. A 3-dimensional hot-wire anemometer system was used to measure the velocity field in the vicinity of the defroster nozzle jet flow and the velocity distributions near the windshield interior surface. At first, two cases of with- and without-duct inlet guide vanes were considered as the test condition, and then three cases of the duct inlet guide vane were tested to determine the optimum guide vane shape and their positions. The arrangement of the duct inlet guide vanes has an effect on the improved flowrate distribution at the defroster nozzle exit and near the windshield interior surface. However, the application of the lots of guide vane to control the flow direction leads to increase the flow resistance, resulting in the decreased flowrate issuing from the defroster nozzle. The shape of the duct inlet guide vane affects not only the flowrate distribution between the driver side and the assistant driver side but also the reduction of the flow resistance in the defrost duct system.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.27 no.10
• /
• pp.1686-1694
• /
• 2003

The foam-filled tube beams can be used for the front rail and firewall structures to absorb impact energy during frontal or side collision of vehicles. In the case of side collision where bending is involved in the crushing mechanism, the foam filler would be effective in maintaining progressive crushing of the thin-walled structures so that much impact energy could be absorbed. In this study, bending behaviors of the closed-cell-aluminum-alloy-foam-filled stainless steel tube were investigated. The various foam-filled specimens including piecewise fillers were prepared and tested. The aluminum-alloy-foam filling offered the significant increase of bending resistance. Their suppression of the inward fold formation at the compression flange as well as the multiple propagating folds led to the increase of load carrying capacity of specimens. Moreover, the piecewise foams would provide the easier way to fill the thin-walled shell structures without the drawback of strength.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.9
• /
• pp.4391-4394
• /
• 2016

Background: Platinum-based regimens are effective treatments for advanced non-small cell lung cancer (NSCLC), but the five-year survival rate is still less than 20%. One possible factor appears to be resistance involving polymorphisms in the CTR1 gene which plays an importance role in accumulation of platinum in the cytoplasm. Purpose: To establish both prevalence of CTR1 polymorphism and its impact on treatment related toxicity in Thai advanced NSCLC patients. Materials and Methods: Thirty-two advanced NSCLC participants received carboplatin and gemcitabine during January to June 2016 at King Chulalongkorn Memorial Hospital (KCMH) were recruited for analysis of the CTR1 rs12686377 genotype. These participants were planning to be treated with platinum-based chemotherapy for at least two cycles. Results: Allele frequency of CTR1 polymorphism $G{\rightarrow}T$ was found to be 25%. The results showed that genetic polymorphism at CTR1 rs12686377 was associated with emesis side effects (P = 0.020) and neuropathic symptoms (P = 0.010). In addition, hematologic side effects in terms of anemia also tended to be related to this polymorphism. Conclusions: This is the first study suggesting that polymorphism at CTR1 rs12686377 may be associated with toxicity from platinum-based regimens. Therefore, it could be a factor to aid in treatment decision-making.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.51-56
• /
• 2007

Pantograph of the electric train is the important part receiving current by adhereing contact wire. Wearing rate of pantograph or contact wire is changed by the type of pantograph and material of adhering part. In special, the weather influences the relative wearing rate and wearing type of pantograph Slider and Contact wire with steep wearing in arc and life cycle of pantograph slider. Presently, the weather causes side-wearing and over-wearing of pantograph slide installed in electric train. So it is difficult to manage and operate the electric train. Although the quality of slide using in line4 vehicle was finished the test in line 2 vehicle experimentally, it has to apply after pantograph is installed in some electric trains and check the influence in it and contact wire. It is because line4 section is very different from line2 section. Experimental application is the sequence to certify the safety and abrasion resistance importantly by enlarging experimental application with increase of the experimental electric train. The lenth of line4 in Seoul Metro is 71.5[km]. It is long section. The line is mixed DC 1,500[V] section and AC 25,000[V] section. It has underground section of 41.5[km] and ground section of 30[km]. Ground section is about 42% and receives much influence in the rain during the rainy season. After experimental application we found that this pantograph slide has twice as much abrasion resistance despite a little deviation and found the occurrence probability of arc and side-wearing is decreased considerably.

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.4 s.181
• /
• pp.116-123
• /
• 2006

During the last two decades, many researchers investigated influences of stress triaxiality on ductile fracture for various specimens and structures. With respect to a transferability issue, the local approach reflecting micro-mechanical specifics is one of effective methods to predict constraint effects. In this paper, the applicability of the local approach was examined through a series of finite element analyses incorporating modified GTN (Gurson-Tvergaard-Needleman) and Rousselier models as well as fracture toughness tests. To achieve this goal, fracture resistance (J-R) curves of several types of compact tension (CT) specimens with various crack length, with various thickness and with/without 20% side- grooves were estimated. Then. the constraint effects were examined by comparing the numerically estimated J-R curves with experimentally determined ones. The assessment results showed that the damage models might be used as useful tool for fracture toughness estimation and both the crack length and thickness effects should be considered for realistic structural integrity evaluation.