• 대한미세수술학회:학술대회논문집
• /
• 1995.11a
• /
• pp.74.1-74.1
• /
• 1995

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.24 no.6
• /
• pp.206-216
• /
• 2020

As the number of aging railway bridges in Korea increases, maintenance costs due to aging are increasing and continuous management is becoming more important. However, while the number of old facilities to be managed increases, there is a shortage of professional personnel capable of inspecting and diagnosing these old facilities. To solve these problems, this study presents an improved model that can detect Local damage to structures using machine learning techniques of AI technology. To construct a damage detection machine learning model, an analysis model of the bridge was set by referring to the design drawing of a non-ballasted plate-girder railroad bridge. Static strain data according to the damage scenario was extracted with the analysis model, and the Local damage index based on the reliability of the bridge was presented using statistical techniques. Damage was performed in a three-step process of identifying the damage existence, the damage location, and the damage severity. In the estimation of the damage severity, a linear regression model was additionally considered to detect random damage. Finally, the random damage location was estimated and verified using a machine learning-based damage detection classification learning model and a regression model.

• Journal of Korean Orthopaedic Sports Medicine
• /
• v.10 no.2
• /
• pp.86-93
• /
• 2011

Purpose: The purpose of this study was to analyze the characteristics of the injuries of the national elite Taekwondo players with the best performance in the international championship competition. Materials and Methods: Fifty-two athletes who got the injury in the 2011 Gyeongju World Taekwondo Championship competition were included in this sturdy. 950 members of national team of 146 countries participated in this game, 1,063 matches were performed. We analyzed the characteristics of the injuries such as injury rate by gender, age, weight class, injured region and injury type. Results: Fifty-two athletes of 950 athletes in 1,063 matches got injured and injury rate was 5.47 per 100 participants and 24.47/1,000 athlete-exposures. Injury rate of female athletes was higher than mail, but there was no significant statistical difference (p=0.512). Injury rate of over 30 years old was 17.39 per 100 participants, and injury rate of over 87 kg in male weight class and 68 to 73kg in female weight class were highest than other groups, but there was no significant statistical difference (p=0.838). Overall injury rate of the lower extremity was 13.17/1,000 A-E, higher than upper extremity or head and neck or trunk, but injury rate of the hand was 5.17/1,000 A-E, highest as a specific injured region, followed by the knee, 4.70/1,000 A-E (p=0.714). Injury rate of the sprain was 10.81/1,000 A-E, highest as an injury type, the second most common injury type was the fracture, 5.40/1,000 A-E in men, and was the contusion, 9.63/1,000 A-E in women (p=0.033). As one of the most serious injury, 4 of 8 fractures were occurred in hand. Conclusion: Overall injury rate of the elite Taekwondo players in 2011 Gyeongju World Taekwondo Championship was 5.47 per 100 participants and 24.46 per 1,000 athlete exposures. Although the most common type of injury was the sprain of the knee and ankle, the fractures were more commonly occurred in hand.

• Korean Journal of Food Science and Technology
• /
• v.47 no.1
• /
• pp.81-86
• /
• 2015

Intense pulsed light (IPL), a nonthermal technology, has attracted increasing interest as a food processing technology. However, its efficacy in inactivating microorganisms has not been evaluated thoroughly. In this study, we investigated the influence of IPL treatment on the inactivation of Escherichia coli O157:H7 depending on light intensity, treatment time, and pulse number. Increased light intensity from 500 V to 1,000 V, raised the inactivation rate at room temperature. At 1000 V, the cell numbers were reduced by 7.1 log cycles within 120 s. In addition, increased pulse number or decreased distance between the light source and sample surface also led to an increase in the inactivation rate. IPL exposure caused a significant increase in the absorption at 260 nm of the suspending agent used in our experiments. This indicates that IPL-treated cells were damaged, consequently releasing intracellular materials. The growth of IPL-irradiated cells were delayed by about 5 h. The degree of damage to the cells after IPL treatment was confimed by transmission electron microscopy.

• Journal of Yeungnam Medical Science
• /
• v.19 no.1
• /
• pp.49-54
• /
• 2002

The central pain in patient with spinal cord injury is a common and disabling sequela. The microsurgical DREZ(Dorsal Root Entry Zone)otomy is a surgical procedure effective in the treatment of intractable pain and spasticity in spinal cord injured patients. It consists of a microsurgical lesions performed in the ventrolateral region of the dorsal root entry zone at the selected levels. This report presents one case with incomplete paraplegia patient, who had chronic central neuropathic pain ineffective to many conservative treatments in bilateral T10 and right T11 segments and both lower extremities, is relieved from the pain after microsurgical DREZotomy. In conclusion, microsurgical DREZotomy is one method of effective treatments for spinal cord injured patients with intractable central neuropathic pain.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.4
• /
• pp.447-452
• /
• 2011

It is well known that the dominant damage mechanisms in high-temperature steam turbine facilities such as rotor and casing are creep and fatigue damages. Even though coupling of creep and fatigue should be considered while predicting the life of turbine facilities, the remaining life of large steam turbine facilities is generally determined on the basis of creep damage because the turbines must generate stable base-load power and because they are operated at a high temperature and pressure for a long time. Almost every large steam turbine in Korea has been operated for more than 20 years and is made of steel containing various amounts of principal alloying elements nickel, chromium, molybdenum, and vanadium. In this study, creep damage model of 1Cr1Mo1/4V steel for turbine rotor is proposed and that can assess the high temperature creep life of large steam turbine facilities is proposed.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.329-329
• /
• 2010

반도체 및 디스플레이의 진공부품은 알루미늄 모제에 전해연마법(electrolytic polishing), 양극산화피막법(Anodizing), 플라즈마 용사법(Plasma spray) 등을 사용하여 $Al_2O_3$ 피막을 성장시켜 사용되고 있다. 반도체 제조공정 중 30~40% 이상의 비중을 차지하는 식각(etching) 및 증착(deposition) 공정은 대부분 플라즈마를 사용하고 있다. 플라즈마에 의해 화학적, 물리적 침식이 발생하여 코팅막에 손상을 일으켜 코팅막이 깨지거나 박리되면서 다량의 Particle을 생성함으로써 생산수율에도 문제를 야기 시킨다고 알려져 있다. 하지만 이들 코팅막을 평가하는 방법은 거의 전무하여 산업계에서 많은 애로를 겪고 있다. 이러한 코팅부품의 내플라즈마 성능평가 방법과 기준이 없어 적절한 교체시기를 파악하기 위한 코팅부품의 손상정도를 정량화 및 평가 방법의 표준화를 구축하는 연구를 수행하였다. 본 연구에서는 이러한 소재의 특성평가를 위해 공정에서 사용 중 손상되어 교체된 샘플의 모폴로지 관찰하고 내전압 측정으로 전기적 특성을 분석하여 손상 전, 후의 변화를 관찰하였다. 또한 플라즈마의 영향에 따른 코팅 막 형태 변화 및 전기적 특성의 변화를 알아보기 위하여 양극산화피막법(Anodizing)으로 $Al_2O_3$를 성장시킨 평가용 샘플을 제작한 후, Plasma chamber 장비를 이용하여 플라즈마 처리에 따른 코팅막의 내전압, 식각율, 표면 미세구조의 변화를 측정하였고 이를 종합적으로 고려하여 진공 장비용 코팅부품의 공정영향에 의한 내플라즈마 특성평가방법 개발에 관하여 연구하였다. 이러한 실험을 통해 플라즈마 처리 후 코팅 막에 크랙이 발생되는 것을 확인할 수 있었고 코팅 막의 손상으로 전기적 특성이 감소를 것을 확인할 수 있었다. 또한 ISPM 장비를 이용하여 진공 장비용 코팅부품이 플라즈마 공정에서 발생하는 오염 입자를 측정할 수 있는 방법을 연구하였다. 이러한 결과를 이용하여 진공공정에서 사용되는 코팅부품이 플라즈마에 의한 손상정도를 정량화 하고 평가방법을 개발하여 부품 양산업체의 진공장비용 코팅부품 개발 신뢰성 향상이 가능할 것으로 본다.

• 재활복지
• /
• v.22 no.4
• /
• pp.83-102
• /
• 2018

The purpose of this study is to provide basic data for effective management and prevention of chronic diseases and secondary complications as elderly spinal cord injuries(SCI). The subjects were 200 spinal cord injuries admitted to S hospital from April, 2013 to April, 2018. We investigated the occurrence of chronic diseases and secondary complication through medical records. The results showed that SCI were affected chronic diseases and secondary complications over 50years. The prevalence of chronic diseases and secondary complications over 50 years of age had the odds ratio 11.8 times higher in hypertension and 6.7 times diabetes mellitus. Secondary complications had the odds ratio Osteoporosis 7.5 times, Pneumonia 5.2 times, and central pain 0.4 times. We suggest that continuous management and service of chronic diseases and secondary complications of elderly SCI are necessary. It will be necessary to expand the target population and to study various characteristics including.

• Fire Science and Engineering
• /
• v.33 no.2
• /
• pp.139-144
• /
• 2019

The increase in the elderly population also increased the damage and deaths of the elderly drivers. However, studies on the severity and severity of the elderly driver are not actively conducted and the factors are unknown. In this study, I tried to find out the factors affecting the damage and severity of the elderly driver in the frontal collision and to utilize them additionally in the severity classification. Collision Deformation Classification (CDC) Code was used to check the extent of damage to the vehicle. Abbreviated Injury Scale (AIS) was used to determine the injury parts and severity of injury, and the Injury Severity Score (ISS) to confirm the severity of the patient. The odds ratios of severe injury patients were found to be 7.381 in the subjects with 5 or more deformation extent and the ${\beta}$ value of the deformation extent was 0.453 in the analysis of the severity by linear regression analysis. Therefore, the degree of deformation extent of 5 or more can be suggested as a criterion that can be used additionally to the severity classification in the elderly driver.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.33 no.6
• /
• pp.401-409
• /
• 2020

Seismic fragility assessments include a procedure to combine the random variables of response and capacity to produce the relationship between failure probability and seismic intensity. The evaluation of the failure probability of simultaneous multiple failures of two or more components assumes that the failure probability of each component is independent of those of the others. However, a correlation is expected to exist because several random factors have the same cause. The multiple-failure probability can differ depending on this correlation and may be unconservative without considering the seismic correlation. Therefore, a practical methodology for fragility assessment should be evaluated using the seismic correlation and correlation coefficient for each random variable. In this study, several random variables were selected for numerical evaluation of the correlation coefficient. The correlation coefficient was then compared with each variable and the combined variables. The correlation coefficient using simplified and complex models were also compared to determine and analyze the differences between each of the approaches.