• Journal of the Korean Society for Precision Engineering
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• v.29 no.3
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• pp.307-312
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• 2012

This study aims to investigate the effect of the post weld treatments on the fatigue life of T-type welded structure made by a SM50A steel material, generally used for excavators, because changes in the geometry, material and surface properties of welded regions affect the fatigue life of welded structures. T-type test specimens were prepared by the CO2 welding of rolled steel plates (SM50A steel) with a thickness of 10 mm at a welding speed of 30 cm/min and these Ttype welded specimens were further treated by UIT (Ultrasonic Impact Treatment) and/or toegrinding post welding treatment methods. In order to investigate improvements on the fatigue life of the samples. 3-point bending fatigue tests were conducted with a stress ratio of R=0.1 under a cyclic loading environment at a frequency of 5 Hz, via a hydraulic fatigue testing machine (${\pm}100\;kN$, MTS 809). The tests were performed at room temperature. The fatigue life of UIT specimens was approximately 25 times longer than that of as-welded specimens at a stress amplitude of 281 MPa, while toe-grinding specimens exhibited 4.15 times longer fatigue life. The current results could provide important guidelines to determine the proper post weld treatment methodologies of T-type welded parts for excavators with a satisfactory fatigue life although under severe operating conditions.

• Journal of Trauma and Injury
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• v.30 no.1
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• pp.6-11
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• 2017

Purpose: The establishment of the trauma system has changed the quality of trauma care in many countries. As one of the first designated level I trauma centers in Korea, we hypothesized that there were changes in laparotomy patterns and subsequent survival rates after the center was established. Methods: This was a 5-year retrospective study of all severe hemoperitoneum patients who were transfused with more than 10 units of packed red blood cells (RBCs) within 24 h of hospitalization. Variables related to trauma were collected throughout the study period, and the patients admitted before (period 1) and after (period 2) the establishment of a trauma center were compared. Results: Forty-five patients were managed from January 2009 to March 2015. The baseline patient characteristics of the two groups, including age, Injury Severity Score, blood pressure, and hemoglobin levels, were similar. The time to the operating room (OR) was $144.3{\pm}51.5$ min (period 1) and $79.9{\pm}44.1$ min (period 2) (p<0.0001). Damage control surgery (DCS) was performed in 17% of patients during period 1 and in 73% during period 2. The number of actual survivors (n=10) was higher than expected (n=8) in period 2. Conclusion: This is the first study analyzing the impact of a trauma center on the management of specific injuries, such as severe hemoperitoneum, in patients in Korea. During the study, the time to OR was shortened and DCS was used to a greater extent as a surgical procedure.

• Journal of Trauma and Injury
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• v.30 no.4
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• pp.166-172
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• 2017

Purpose: Thoracic traumas represent 10-15% of all traumas and are responsible for 25% of all trauma mortalities. Traumatic cardiac injury (TCI) is one of the major causes of death in trauma patients, rarely present in living patients who are transferred to the hospital. TCI is a challenge for trauma surgeons as it provides a short therapeutic window and the management is often dictated by the underlying mechanism and hemodynamic status. This study is to describe our experiences about emergency cardiac surgery in TCI. Methods: This is a retrospective clinical analysis of patients who had undergone emergency cardiac surgery in our trauma center from January 2014 to December 2016. Demographics, physiologic data, mechanism of injuries, the timing of surgical interventions, surgical approaches and outcomes were reviewed. Results: The number of trauma patients who arrived at our hospital during the study period was 9,501. Among them, 884 had chest injuries, 434 patients were evaluated to have over 3 abbreviated injury scale (AIS) about the chest. Cardiac surgeries were performed in 18 patients, and 13 (72.2%) of them were male. The median age was 47.0 years (quartiles 35.0, 55.3). Eleven patients (61.1%) had penetrating traumas. Prehospital cardiopulmonary resuscitations (CPR) were performed in 4 patients (22.2%). All of them had undergone emergency department thoracotomy (EDT), and they were transferred to the operating room for definitive repair of the cardiac injury, but all of them expired in the intensive care unit. Most commonly performed surgical incision was median sternotomy (n=13, 72.2%). The majority site of injury was right ventricle (n=11, 61.1%). The mortality rate was 22.2% (n=4). Conclusions: This study suggests that penetrating cardiac injuries are more often than blunt cardiac injury in TCI, and the majority site of injury is right ventricle. Also, it suggests prehospital CPR and EDT are significantly responsible for high mortality in TCI.

• Progress in Superconductivity and Cryogenics
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• v.18 no.1
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• pp.41-45
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• 2016

The technology of supplying the electric power by wireless power transfer (WPT) is expected for the next generation power feeding system since it can supply the power to portable devices without any connectors through large air gap. As such a technology based on strongly coupled electromagnetic resonators is possible to deliver the large power and recharge them seamlessly; it has been considered as a noble option to wireless power charging system in the various power applications. Recently, various HTS wires have now been manufactured for demonstrations of transmission cables, motors, MAGLEV, and other electrical power components. However, since the HTS magnets have a lower index n value intrinsically, they are required to be charged from external power system through leads or internal power system. The portable area is limited as well as the cryogen system is bulkier. Thus, we proposed a novel design of wireless power charging system for superconducting HTS magnet (WPC4SM) based on resonance coupling method. As the novel system makes possible a wireless power charging using copper resonance coupled coils, it enables to portable charging conveniently in the superconducting applications. This paper presented the conceptual design and operating characteristics of WPC4SM using different shapes' copper resonance coil. The proposed system consists of four components; RF generator of 370 kHz, copper resonance coupling coils, impedance matching (IM) subsystem and HTS magnet including rectifier system.

• Journal of The Korea Institute of Healthcare Architecture
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• v.22 no.3
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• pp.45-56
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• 2016

Purpose: The MERS(Middle East Respiratory Syndrome) outbreaks in Korea highlighted dramatically the failings of traditional hospital environment for controlling or preventing infections among both patients and healthcare workers. MERS is transmitted by droplets that can be airborne over a limited area. The point should be emphasized that MERS in South Korea was predominantly a hospital-acquired (not a community-acquired) infection, because approximately 93% of MERS cases were resulted from exposure in hospital settings. This paper tries to suggest the design guidelines of negative pressured isolation ward for the sake of proper control of severe respiratory infectious diseases. Methods: Literature survey on the design guideline and regulations of airborne infection wards in Korea, Europe U.K. and CDC of U.S. have been carries out. 4 special infection wards in Hongkong, Germany, Japan and Korea have been surveyed in order to make the best use of the experiences related to facility design and operations. Results: Operating system influencing the facility design, space organizations of infectious ward including required space and zoning, and circulations of patients, staffs and materials are proposed. Implications: The results of this paper can be the basic data for the design of the airborne infection ward and relevant regulations. Afterwards in-depth study such as the development of space standards for the single bedroom, locker room and so on could be explored.

• The Journal of Korean Academic Society of Nursing Education
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• v.16 no.1
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• pp.92-100
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• 2010

Purpose: This study was conducted to investigate the cognition level and the performance level of universal precautions on blood-borne infections and to analyze related-factors on the performance level for universal precautions among the nurses. Method: A total of 166 nurses participated in the survey. We performed multiple linear regression to assess the related-factors on the performance level for universal precautions. Result: The mean scores of cognition and performance level for universal precautions were 65.61(${\pm}8.74$) and 53.98(${\pm}8.42$) respectively. The mean score of the cognition level was significantly lower than the performance level in all items. The cognition level was associated with the working field. The performance level was highest for nurses working over 36 years, nurses in university hospitals, and nurses in the operating room. The cognitive level for universal precautions, education level, exposure to blood-borne infection, family's income, and marital status significantly predicted the performance level for universal precautions in the multiple linear regression model (Adjusted $R^2=0.42$). Conclusion: The cognition level for universal precautions is the strongest predictor on the performance level for universal precautions. An integrated approach should incorporate training experiences to improve cognition and perception of risk on universal precautions for preventing blood-borne infections.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.9 s.180
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• pp.2183-2190
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• 2000

A thermal aging is observed in a primary reactor cooling system(RCS) made of a casting stainless steel when the RCS is exposed for long period at the reactor operating temperature, 290~3300C An investigation of effects of thermal aging on a low cycle fatigue characteristics included a stress variations caused by a reactor operation and trip, is required. The purpose of the present investigation is to find an effect of a thermal aging of the CF8M on a low cycle fatigue life. The specimen of CF8M are prepared by an artificially accelerated aging technique holding 300 and 1800hr at 4300C respectively. The low cycle fatigue tests for the virgin and two aged specimens are performed at the room temperature for various strain amplitudes($\varepsilon$ta), 0.3, 0.5, 0.8, 1.0, 1.2 and 1.5% strain. Through the experiment, it is found that the fatigue life is rapidly reduced with an creasing of the aging time. The experimental fatigue life estimation formulas between the virgin and two aged specimen are obtained and are proposed to a analysis purpose.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.8
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• pp.951-956
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• 2011

Inconel alloys are generally used as steam generator tubes in nuclear power plants. These alloys are highnickel chromium alloys that exhibit excellent resistance to aqueous corrosion. In this paper, the effects of elevated temperatures such as an operating temperature of $320^{\circ}C$ on the fretting fatigue behavior of inconel 600 and 690. We observed that the plain and fretting fatigue limits at $320^{\circ}C$ were slightly lower than those at room temperature. The frictional forces varied depending on the number of load cycles. After each test, we studied the fretting fatigue mechanisms via SEM observations. These results can be used for structural integrity evaluations at elevated temperatures and for studying fretting damage in steam generator systems.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.1701-1704
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• 2016

Background: Stomach cancer (SC) is the second leading cause of cancer death with the rate of 10.4% in the world. The correlation between the incidence and mortality rates of SC and human development index (HDI) has not been globally determined. Therefore, this study aimed to determine the association between the incidence and mortality rates of SC and HDI in various regions. Materials and Methods: In this global ecological study, we used the data about the incidence and mortality rate of SC and HDI from the global cancer project and the United Nations Development Programme database, respectively. Results: In 2012, SCs were estimated to have affected a total of 951,594 individuals (crude rate: 13.5 per 100,000 individuals) with a male/female ratio of 1.97, and caused 723,073 deaths worldwide (crude rate: 10.2 per 100,000 individuals). There was a positive correlation between the HDI and both incidence (r=0.28, P<0.05) and mortality rates of SC (r=0.13, P = 0.1) in the world in 2012. Conclusions: The high incidence and mortality rates of SC in countries with high and very high HDI is remarkable which should be the top priority of interventions for global health policymakers. In addition, health programs should be provided to reduce the burden of this disease in the regions with high incidence and mortality rates of SC.

• Korean Journal of Adult Nursing
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• v.12 no.4
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• pp.666-677
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• 2000

The purpose of this study was to identify the needs which were perceived by patients who were received spinal anesthesia for surgery. The subjects consisted of 50 adult patients who were admitted to 2 university hospitals and 2 general hospitals in Pusan city and 1 general hospital in Koje City for surgery under spinal anesthesia. Thirty eight percent of subjects received information about anesthesia before the operation. The instrument for this study was developed by the researcher based on literature and a pretest. Data were collected from December 10, 1999 to February 10, 2000 and were analyzed by content analysis. The results were that there were 533 meaningful statements in the needs of spinal anesthesia patients. The needs of spinal anesthesia patients had 51 items (preoperation (6), induction of anesthesia(5), intraoperation (27), postoperation(13)) and 6 categories (information, emotional welfare, physical welfare, post anesthetic management, control of physical environment, humane treatment). From the results, it can be concluded that: 1. In the pre-operation period, we have to explain anesthesia procedures, adequate position of anesthesia, duration before anesthesia wears off and sensation of paralysis. We have to supply emotional support to relieve anxiety because of anesthesia. 2. In induction of anesthesia, we have to support patient's position for anesthesia, and relieve anxiety so that patients participate in induction of anesthesia well. 3. In intra-operative period, we have to check the level of anesthesia, and keep up a comfortable position for operation and care for physical discomfort such as thirst, nausea, vomiting, dyspnea and to maintain body temperature of the patient. Since the patient is conscious, we have to communicate with the patient to relieve anxiety, maintain privacy, inform the patient of the process of the operation and encourage the surgeon to explain the outcome of the operation. The operating team needs the careful about what they say and to place the instrument well. We have to ventilate the room air and reduce noise. 4. In the post-operative period, we have to explain the purpose and duration of bed rest, complications of anesthesia and care for physical discomfort such as pain, dysuria, headache, backache. Also we have to maintain body temperature of the patient and maintain privacy.