• Journal of Chest Surgery
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• v.37 no.2
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• pp.146-153
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• 2004

As the experience of coronary artery bypass grafting (CABG) has been accumulated, the number of reoperation after CABG is increasing. We analyzed our clinical experience of redo-CABG. Material and Method: Fourteen patients who underwent redo-CABG between Jan. 1994 and Dec. 2002 were included in this study. The mean period from the first operation to reoperation was 66$\pm$56 (3∼157) months, and the average ages were 62.8$\pm$8.7 (51∼78) years. The survivors were followed up 39$\pm$29 (4∼101) months postoperatively. Indications of reoperation were stenosis or occlusion of previous grafts in 11 patients, progression of native coronary artery disease in one patient, and both etiologies in two patients. Result: There were two in-hospital mortalities (14.3%) resulting from low cardiac output syndrome, Postoperative morbidities were perioperative myocardiac infarction in 2 patients (14.3%), mediastinitis in one patient (7.2%), duodenal perforation in one patient, ischemic necrosis of the lower extremity in one patient, gastric perforation after mesenteric infarct in one patient, delayed brain infarct in one patient, and intraoperative splenic rupture in one patient. There was one late mortality at six months postoperatively during the follow up. There was no angina recurrence during the follow up. Conclusion: Although redo CABG demonstrated relatively high operative mortalities and morbidities, postoperative status and clinical outcome of the survivors were favorable.

• Fire Science and Engineering
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• v.20 no.3 s.63
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• pp.65-70
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• 2006

From the beginning of the construction stage, the fire protection regulation for the nuclear power plants conforms to the design requirements for the acquisition of the license permit. This regulation is based on the plant status of the normal operation, but it is not enough to be used as an application standard for fire protection at the transient mode of the plant and the outage time for refueling as well as for the plant decommissioning. While the advanced fire protection requirement that has been developed in America recently suggests the performance-based requirement and management rule applicable to the overall life time of the plant, it simply represents the conceptual application. It means that it can not be treated as appropriate standards because it does not deal with the qualitative and quantitative approach in specific ways. By the way, with the use of the performance-based fire risk analysis, the dynamic behavior of the heat and smoke at the fire compartment of the nuclear power plants can be analyzed and the thermal effect to the safety-related equipment and cables can be evaluated as well. At this paper, it suggests the ways to change the applicable fire protection regulations and the required evaluation items for the fire risk resulted from the plant configuration change with an intent to introduce the state-of-the-art quantitative fire risk analysis technology at the domestic nuclear power plants.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.5
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• pp.25-37
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• 2010

This study is aimed at enhancing mobility rights for the transportation underprivileged that has been made light of relatively compared to normal people. In order to do this, we've suggested having ITS (Intelligent Traffic System) built and improving satisfaction through the test operation of its main system. The existing sound signal device for the visually handicapped has one problem with managing it. Because, the people in charge of it had to visit each problematic site directly to maintain and fix some problems every time it was out of order. Moreover, it couldn't provide sustainable services about voice guidance and the visually handicapped had to control it by either confirming the location of buttons that were installed on the pillar of traffic light and then pressing one of them or using a remote controller on their own. In order to improve such inconveniences, we have created a new typed sound signal device for the visually handicapped by applying the cutting-edge wireless technology based on ergonomics considering actual road situations. Such technology enables it report the status of signal device and light to them by using its voice guidance system automatically every time they have access to it. Additionally, we've already introduced it to a couple of test areas and then known the fact that they recognized traffic situation more conveniently and safely compared to the existing sound signal device. That is above average in terms of satisfaction. In addition to that, we've provided LTS (Location Tracking System - Location-based service intended for elementary students) by utilizing the existing wireless infrastructure and founded the fact that about 87% of their parents were satisfied with the service based on LTS.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.12
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• pp.99-108
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• 2015

The embedded microcontroller which is operated by the logic gates synchronized on the clock pulse, is gradually used as main controller of mission-critical systems. Severe electrical situations such as high voltage/frequency surge may cause malfunctioning of the clock source. The tolerant system operation is required against the various external electric noise and means the robust design technique is becoming more important issue in system clock failure problems. In this paper, we propose on-chip backup clock change architecture for the automatic clock failure detection. For the this, we adopt the edge detector, noise canceller logic and glitch-free clock changer circuit. The implemented edge detector unit detects the abnormal low-frequency of the clock source and the delay chain circuit of the clock pulse by the noise canceller can cancel out the glitch clock. The externally invalid clock source by detecting the emergency status will be switched to back-up clock source by glitch-free clock changer circuit. The proposed circuits are evaluated by Verilog simulation and the fabricated IC is validated by using test equipment electrical field radiation noise

• The Korean Journal of Emergency Medical Services
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• v.11 no.1
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• pp.53-64
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• 2007

Purpose: Ths study aims to examine characteristics of patients using emergency room after execution of five-day workweek system by government and provide basic materials for operation of efficient emergency room. Methods: Data were collected tbrough medical records of patients visiting emergency room from July of 2004 to October of 2006 and they were analyzed with SPSSlPC 10.0. Conclusion : 1. The number of patients visiting emergency room was average 16.7 persons a day in 2004, 17.5 in 2005 and 18.6 in 2006 and it was found that it was increasing every year since the execution of five-day workweek system 2. Gender distribution of subjects using emergency room was higher in male than in female every year. 3. Means of transport to emergency room were mostly private car and others(public transport or on foot), but use of ambulance was increasing. 4. Residential areas of subjects were mostly 'Myeon area' in 2004~2005, but it was changed to residents at 'Eup area' in 2006. 5. Distribution of patients by medical departments was highest in internal medicine and surgery in 2004~2006 and rate of visiting pediatrics was increasing every year. 6. Time to stay at emergency room was most at 'below 30 min'. in 2004~2006, but cases of stay for 'more than 2 hours' were increasing every year. 7. On presence or absence of trauma in patients visiting emergency room, rate of visit to emergency room with 'no trauma' was higher and this result was increasing every year. 8. As a result of classifying severity of patients visiting emergency room, use rate of emergency room by 'non-emergency' patients was over 90% in 2004~2006 and such a phenomenon was deepened in 2006 compared to that in 2004. 9. Measures after emergency care of patients were most in case of 'discharge' in 2004~2006, but cases of admission to hospital after emergency care were increased every year. 10. According to use of emergency room by a day of the week, use on Sunday was most frequent in 2004~2006, but use on Friday the day before holiday was increasing. 11. According to distribution by age, use by those between '40~49' was most in 2004~2005, but use by those 'below 10' was most in 2006. 12. According to time to visit emergency room, using emergency room at "15:31~23:30 was most in 2004~2006, cases of visiting emergency room at day working hour were decreased every year and those at evening and night working hours were increased. Conclusion: In sum, it was found that characteristics of patients visiting emergency room and their actual status were changed after the execution of five-day workweek system and efforts to rearrange emergency medical system are required.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.6
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• pp.643-656
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• 2019

The development of hot social networking services, including the Internet, has transformed rental car services into IT-based car-sharing services. The car-sharing service is a service that allows people to rent cars online without having to face-to-face. It has become the preffered service among young people who are accustomed to drinking and eating alone. Users can use their smartphones to book their types of cars and hours of rent, and then go to a nearby designated parking lot to use their reserved cars. You can open a designated car door with a smart phone and drive. It is a very convenient service to pay for the distance you drive. However, the car-sharing service already in use in business has the following problems: underage who do not have a driver's license may drive a car borrowed by an acquaintance, the status of a license registered at the time of join membership with a car-sharing company may change to a suspension or cancellation of a license while renting and driving, or even a drunk person may rent a car and drive. In this paper, the method to solve these problems has been studied and proposed. The proposed method is to reduce the cost of investment by a car-sharing service provider and to minimize user inconvenience. And, it was compared and analyzed with the existing method. For the method to be used efficiently, the active operation of the car-sharing company and the government's policies will have to be supported.

• 대한공업교육학회지
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• v.42 no.1
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• pp.125-139
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• 2017

The purpose of this study was to provide a basic research data for increasing the satisfaction by analyzing perception of middle school beginning technology teachers 'technology home economics' class for free semester program. In order to investigate the class operation status, the survey questionnaires from 100 teachers were collected from middle school beginning teachers who teach technology home economics subject currently and analyzed by statistical program(SPSS ver.18). The main results of this study were as follows: First, there was no statistically significant difference to contents and satisfaction of lesson between teachers who experienced free semester program and not. In comparison of male teachers and female teachers, male teachers thought that free semester program was more helpful for student's 'career exploration' than female teachers, and there was statistically significant difference. Second, in the teacher's response according to have practice space and not, the satisfaction average of teachers who have practice space was higher(M=3.64) than those who have not at 'career exploration' and there was statistically significant difference satisfaction. Third, among the teachers who have experienced free semester program, male teachers were having more difficulty 'determining the assessment criteria' than the female teachers and there was statistically significant difference. Fourth, to improve the satisfaction of technical lesson, technology teachers asked to solve lack of practice material, increase of lesson-time, lack of practice space and lesson contents etc. Fifth, technology teachers asked free semester program seminars and information because free semester program lesson contents was given by internet and research groups of technology education.

• Journal of Information Technology and Architecture
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• v.9 no.2
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• pp.177-186
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• 2012

Navy establishes the Naval Task Forces (TF) for many kinds of maritime operations. Then the TF in the maritime environment performs simultaneous component operations such as ASUW (Anti-Surface Warfare), ASW (Anti-Submarine Warfare), AAW (Anti-Aircraft Warfare), and assault operations. The TF consists of many tactical systems for the completion of missions C4I, VOIP (Voice Over Internet Protocol), DMHS (Digital Massage Handling System), and TDLs (Tactical Data Links) such as LINK-11, 16, ISDL (Inter Site Data Link). When the TF executes naval operations to complete a mission, we are interested in the kill chain for the maritime operations in the TF. The kill chain is a standard procedure for the naval operations to crush enemy defenses. Although each ship has a procedure about a manual for 'how to fight', it leave something to be desired for the TF detailed kill chain currently. Therefore, in this paper, we propose the naval TF's kill chain to perform the naval operations. Then, the operational effectiveness of the TF in the kill chain environment is determined through operation scenarios of TDL system implementation. It is to see the operational information sharing effect to a data link model based on MND-AF OV 6c (statement of tracking operational status) in the maritime operations applied to TDL and is to identify improvements in information dissemination process. We made the kill chain of maritime TF for the effective naval operations.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.4
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• pp.337-344
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• 2017

The demand of liquified natural gas is increasing due to environmental issues. This reason has resulted in increasing the capacity of liquified natural gas cargo tank. The Mark-III type primary barrier directly contacts liquified natural gas. Also, the primary barrier is under various loading conditions such as weight of liquified natural gas and sloshing loads. During a ship operation, various loads can cause fatigue failure. Therefore, the fatigue life prediction should be evaluated to prevent leakage of liquified natural gas. In the present study, the fatigue analysis of insulation system including primary barrier is performed using a finite element model. The fatigue life of primary barrier is carried out using a numerical study. The value of principle stress and the location of maximum principle stress range are calculated, and the fatigue life is evaluated. In addition, the effects on the insulation panel status and the arrangement of knot or corrugation are analyzed by comparing the fatigue life of various models. The insulation system which has best structural performance of primary barrier was selected to ensure structural integrity in fatigue assessment. These results can be used as a design guideline and a fundamental study for the fatigue assessment of primary barrier.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.707-712
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• 2014

Purpose: Anastomotic leakage (AL) is associated with high morbidity and mortality, high reoperation rates, and increased hospital length of stay. Here we investigated the risk factors for AL after anterior resection for rectal cancer with a double stapling technique. Patients and Methods: Data for 460 patients who underwent primary anterior resection with a double stapling technique for rectal carcinoma at a single institution from 2003 to 2007 were prospectively collected. All patients experienced a total mesorectal excision (TME) operation. Clinical AL was defined as the presence of leakage signs and confirmed by diagnostic work-up according to ICD-9 codes 997.4, 567.22 (abdominopelvic abscess), and 569.81 (fistula of the intestine). Univariate and logistic regression analyses of 20 variables were undertaken to determine risk factors for AL. Survival was analysed using the Cox regression method. Results: AL was noted in 35 (7.6%) of 460 patients with rectal cancer. :Median age of the patients was 65 (50-74) and 161 (35%) were male. The diagnosis of AL was made between the 6th and 12th postoperative day (POD; mean 8th POD). After univariate and multivariate analysis, age (p=0.004), gender (p=0.007), tumor site (p<0.001), preoperative body mass index (EMI) (p<0.001), the reduction of TSGF on 5th POD less than 10U/ml (p=0.044) and the pH value of pelvic dranage less than or equal to 6.978 on 3rd POD (p<0.001) were selected as 6 independent risk factors for AL. It was shown that significant differences in survival of the patients were AL-related (p<0.001), high ASA score related (p=0.036), high-level EMI related (p=0.007) and advanced TNM stage related