• Journal of the Korean Society for Precision Engineering
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• v.29 no.1
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• pp.96-102
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• 2012

The current establishment of car engineering plastic piping polyethylene (PE) tube used as bonding state or part of the health or safety of fusion is very important. A part of these fusion methods to determine the soundness of the short-term trials and long-term tests can be largely classified. Typical tests included short-term strength, tensile strength, impact strength, compressive strength, resiliency and compression. Polyethylene (PE) pipes installed in the domestic terms of overall penetration rate of 45% has been used. However, polyethylene (PE) pipes have reliability problems, and these occurs mostly in part by defective welding. Therefore, the test is necessary for safety. Non-destructive methods (ultrasonic testing) are difficult to be used. Therefore, Polyethylene (PE) pipe are used. Fusion of thses materilas is necessary in these field however, its technical, and basic research has not been studied well. In this research, short-term strength of welding parts, its tensile strength, hardness, fatigue, and microstructure have been analyzed to find the optimum process conditions to improve mechanical properties.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.112-120
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• 2008

Today, the use of a vacuum cleaner gave us the higher quality of life than past time, but sometimes made us w1comfortable in the house because of the specific noise that is annoying. So we need to study how sound absorbtion materials affect sound power level and sound quality with sound metrics. In this paper, we will measure and calculate sound power level for vacuum cleaner and analyze characteristics of the noise for 10 Signals according to materials positioned in vacuum cleaner. The multiple regression analysis can estimate the nonlinear characteristics of relation between subjective evaluation and sound metrics. So we will develop sound quality index for vacuum sound.

• Proceedings of the KWS Conference
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• 1998.10a
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• pp.288-291
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• 1998

Inconel 600 alloy is used as the material of nuclear steam generator tubing because of its mechanical properties, formability, and corrosion properties. According to reports, the life time of nuclear power plants decreases because of the pitting, intergranular attack, primary water stress corrosion cracking(PWSCC), and intergranular stress corrosion cracking(IGSCC), and denting in the steam generator. The SCC test is very important because of SCC appears in various environment such as solutions, materials, and stress. The C-Rig specimen was made of the steam generator welded sleeve repairing by the pulsed Nd:YAG laser. In the corrosion invironment, corrosion solutions are Primary Water, Caustic, and Sulfate solution and corrosion time is 1624-4877hr. The permitted stress is 30-60ksi.In this C-Ring SCC test is the relationship between corrosion depth, crack and corrosion environment is evaluated. SCC was happens in Sulfate and Corrosion solution but doesn't happen in Primary Water. The corrosion time and stress is very affected by the severely environment of Sulfate or Caustic solution. The microstructure observation indicates that SCC causes interganular failure in the grain boundary of vertical direction.

• Journal of Chest Surgery
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• v.3 no.1
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• pp.3-12
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• 1970

During the last 10 years of period, one hundred patients with various pulmonary diseases were pneumonectomized upon at the Department of Chest Surgery of Pusan University Hospital. This paper is concerned with the clnical results of these patients along with the serious postoperative complications such as postoperative intrapleural infection and hemorrhage. The results were obtained as follows. 1.Left pneumonectomy was done in sixty-six of 100 patients [66 %] and the right one was done in the rest thirty-four[34 %]. The ratio between left and right was nearly 2:1. 2.Of all oostoperative complications, the intrapleural infection was most common, and these were 53 % in empyema thoracis and 12.7 % in pulmonary tuberculosis respectively. 3.More postoperative complications could be seen after right pneumonectomy than the left one. 4.It was thought that the postoperative intrapleural infection was closely correlated with the methods of pleural dissection at pneumonectomy,postoperatlve tube drainage, time of operation, massive hemorrhage during operation, prolongation of bleeding time, and dysfunction of the liver. 5.The repeated thoracenteses with infusion of neomycin into the infected thoracic cavity and intravenous administrations of the high units of penicillin were effective in treatment of the postoperative intrapleural infection, however, the refractory cases have to be cured by thoracoplasty with open window. 6.Immediate secondary open thoracotomy appears to be the method of choice in life saving who developed massive intrathoracic hemorrhage after pneumonectomy. 7.The mortality rate was 10 % in our cases and the main causes of death were postoperative respiratory insufficiency, pulmonary edema, hemorrhage and sudden cardiac arrest.

• Journal of Chest Surgery
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• v.26 no.8
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• pp.613-619
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• 1993

As developing surgical techniques and postoperative cares, a pneumonectomy is a relatively popular surgical method in disease which is not treated completely with other type of pulmonary resection, but a postpneumonectomy complication is a life-threatening serious problem if it occurred. We performed one hundred twenty-five cases of pneumonectomy for treatment of various causes of pulmonary diseases in Kosin Medical College during about ten years, and we experienced 41 cases of postoperative complications in 29 patients, so we analyzed them. The most common complication is an empyema thoracis in 13 cases[10.4%], of which one case combined with bronchopleural fistula died on early postoperative day. Of them except one case, the early postoperative empyema thoracis[within 30 days] were 6 cases, and the late postoperative empyema thoracis[above 30 days] were 6 cases. The main etiologic pathogens were a staphylococcus in early postoperative empyema and a streptococcus in late postoperative empyema, but the most cases were mixed infections with pseudomonas, klebsiella, acinectobacter, and candida. The treatment of postoperative empyema thoracis were that 4 cases were treated with open drainage using chest tube, 7 cases with Clagett`s operation, and 1 case with thoracoplasty. The next common complication was a postoperative serious respiratory insufficiency in 7 cases. And the other complications were massive postoperative bleeding in 5 cases, of which 2 cases advanced to occurrence of postoperative empyema thoracis, and wound disruption in 4 cases, cardiac arrhythmia in 3 cases, contralateral pneumothorax and pneumonia in each of 2 cases, esophagopleural fistula in 1 case. The postoperative deaths were 9 cases[7.2%] of 125 cases, the causes of death were respiratory insufficiency in 6 cases, sepsis in 2 cases, and cardiac arrhythmia in 1 case.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.05a
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• pp.115-121
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• 2000

As the development of industry water quality of river is going to bad because of waste water of an industrial complex and general home agricultural chemicals exhaust of $SO_3$ and CO gas acid rain and so on. Corrosion damage of boiler factory equipment and so forth occur quickly due to using of the polluted water resulting in increasing leak accident. Especially working life of hot water boiler using the polluted water becomes more short and energy loss increases. The cathodic protection method is the most economical and reliable one to prevent corrosion damage of steel structures. Mg-base alloys galvanic anode protection of cathodic protection method is suitable for than application of hot water boiler using water with high specific resistance such as tap water. This paper is studied on the cathodic protection characteristics of how water boiler. In tap water and 0.001mol/$\ell$ NaCl solution the characteristics of anodic polarization of Mg-base alloys galvanic anode and tube material is investigated the measurement of cathodic protection potential according to the time elaspsed is carried out.

• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1406-1416
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• 2017

In complex and large-scale industries, properly designed fault detection and identification (FDI) systems considerably improve safety, reliability and availability of target processes. In thermal power plants (TPPs), generating units operate under very dangerous conditions; system failures can cause severe loss of life and property. In this paper, we propose a bagged auto-associative kernel regression (AAKR)-based FDI approach for steam boilers in TPPs. AAKR estimates new query vectors by online local modeling, and is suitable for TPPs operating under various load levels. By combining the bagging method, more stable and reliable estimations can be achieved, since the effects of random fluctuations decrease because of ensemble averaging. To validate performance, the proposed method and comparison methods (i.e., a clustering-based method and principal component analysis) are applied to failure data due to water wall tube leakage gathered from a 250 MW coal-fired TPP. Experimental results show that the proposed method fulfills reasonable false alarm rates and, at the same time, achieves better fault detection performance than the comparison methods. After performing fault detection, contribution analysis is carried out to identify fault variables; this helps operators to confirm the types of faults and efficiently take preventive actions.

• Nutrition Research and Practice
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• v.5 no.1
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• pp.3-10
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• 2011

Women's nutrition has received little attention in nutrition programming, even though clinical trials and intervention trials have suggested that dietary improvement or supplementation with several nutrients may improve their health, especially in low-income settings, the main focus of this paper. Most attention so far has focused on how improvements in maternal nutrition can improve health outcomes for infants and young children. Adequate vitamin D and calcium nutrition throughout life may reduce the risk of osteoporosis, and calcium supplementation during pregnancy may reduce preeclampsia and low birth weight. To reduce neural tube defects, additional folic acid and possibly vitamin $B_{12}$ need to be provided to non-deficient women before they know they are pregnant. This is best achieved by fortifying a staple food. It is unclear whether maternal vitamin A supplementation will lead to improved health outcomes for mother or child. Iron, iodine and zinc supplementation are widely needed for deficient women. Multimicronutrient supplementation (MMS) in place of the more common iron-folate supplements given in pregnancy in low-income countries may slightly increase birth weight, but its impact on neonatal mortality and other outcomes is unclear. More sustainable alternative approaches deserve greater research attention.

• Structural Monitoring and Maintenance
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• v.2 no.1
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• pp.65-75
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• 2015

Among the destruction instances of half-through arch bridges, the shorter hangers are more likely to be ruined. For a thorough investigation of the hanger system durability, we have studied vehicle impact effect on hangers with vehicle-bridge coupling method for a half-through concrete-filled-steel-tube arch bridge. A numerical method has been applied to simulate the variation of dynamic internal force (stress) in hangers under different vehicle speeds and road surface roughness. The characteristics and differences in impact effect among hangers with different length (position) are compared. The impact effect is further analyzed comprehensively based on the vehicle speed distribution model. Our results show that the dynamic internal force induced by moving vehicles inside the shorter hangers is significantly greater than that inside the longer ones. The largest difference of dynamic internal force among the hangers could be as high as 28%. Our results well explained a common phenomenon in several hanger damage accidents occurred in China. This work forms a basis for hanger system's fatigue analysis and service life evaluation. It also provides a reference to the design, management, maintenance, monitoring, and evaluation for this kind of bridge.

• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1481-1485
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• 2020

The creep behavior of Ni-Cr-W alloy at 950 ℃ has been investigated by a novel creep testing system which is capable of in-situ measurement of strain. Tubular specimens were pressurized with argon gas for effective stresses up to 32 MPa. Experimental results show that the thermal fatigue reduces the creep life of the tubular specimens and with the introduction of thermal cycling fatigue the primary stage disappears and the creep rate higher than the pure thermal creep (without thermal fatigue). Also the creep behavior of Ni-Cr-W alloy doesn't consist in the secondary stage. A new creep equation has been derived and implemented into finite element method. The results from the finite element analyses are in good agreement with the creep experiment.