• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.512-514
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• 2004

The Electro-Optical Camera (EOC) is a high spatial resolution, visible imaging sensor which collects visible image data of the earth's sunlit surface and is the primary payload on KOMPSAT-l. The purpose of the EOC payload is to provide high resolution visible imagery data to support cartography of the Korean Peninsula. The EOC is a push broom-scanned sensor which incorporates a single nadir looking telescope. At the nominal altitude of 685Km with the spacecraft in a nadir pointing attitude, the EOC collects data with a ground sample distance of approximately 6.6 meters and a swath width of around 17Km. The EOC is designed to operate with a duty cycle of up to 2 minutes (contiguous) per orbit over the mission lifetime of 3 years with the functions of programmable gain/offset. The EOC has no pointing mechanism of its own. EOC pointing is accomplished by right and left rolling of the spacecraft, as needed. Under nominal operating conditions, the spacecraft can be rolled to an angle in the range from +/- 15 to 30 degrees to support the collection of stereo data. In this paper, the status of EOC such as temperature, dark calibration, cover operation and thermal control is checked and analyzed by continuously monitored state of health (SOH) data and image data during the mission life of 3 years. The aliveness of EOC and operation continuation beyond mission life is confirmed by the results of the analysis.

• Journal of Korean Society of Transportation
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• v.32 no.2
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• pp.119-129
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• 2014

This study aims to evaluate the accident reduction effects of 'Section Speed Enforcement System' (SSES) operation in freeways. In pursuing the above, this study collects the accident data for 5 years (2 years before operation and 3 years after operation) at all 9 sections where SSESs are operated, and evaluates annually the effects before and after operation using the comparison group method (C.G. Method). The measures of effectiveness are total accidents (TAs), fatal and serious accidents (FSAs), total injuries (TIs) and fatal and serious injuries (FSIs). The main results are as follows. First, TAs and TIs are reduced to 41.7 and 17.1%, respectively. Second, FSAs and FSIs are reduced to 41.7 and 32.2%, respectively. Therefore, SSES has more effectiveness at fatal and serious accident. Third, the accident reduction effect has been increasing, and particularly the effect of 'after three years' is evaluated to be notable.

• Journal of The Korean Digital Architecture Interior Association
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• v.10 no.2
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• pp.5-12
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• 2010

Unlike housing development project that can ensure profit by selling built units, a hotel development depends on long-term business operation to be profitable due to characteristics of service industry. The expected cash flow has substantial uncertainty depending on room occupancy rate and room charge. Thus, even after construction is complete, business risk tends to rise. It is necessary to ensure strategic response to uncertainty in future value of a hotel. The objective of the study is to explore strategic measures to deal with risk and uncertain future value in hotel development project by adopting abandonment option, which is a type of real options. The case in analysis had sevenyears of project period: Two years for construction, and five years for operation; a plan was made to sell the hotel after five years' of operation. For the research purpose, option value ofrecoverable investment amount was estimated, and value of abandonment option was KRW 124.921 billion. When abandonment option is applied, the project value was deemed to be KRW 120.592 billion. Generally, the amount of loss is enormous when a real estate project like a hotel development fails, and therefore, application of option is expected to be an effective measure to leverage uncertainty of a project.

• Journal of Chest Surgery
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• v.24 no.1
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• pp.48-53
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• 1991

This report documents the clinical k pathologic features of 33 patients treated for thymoma for 11 years & 6 months between September 1977 and February 1989. At the Thoracic & Cardiovascular Surgery, Yonsei University, College of Medicine of the group, 31 patients treated with surgery were examined for the result of operation & prognosis. Mean age was 50 years. Thirteen were female and twenty were male. Dyspnea on exertion and chest discomfort were common in the patients without myasthenia gravis. Fourteen patients[42.6%] had myasthenia gravis and one patient had autoimmune thyroid disease. Four patients[12.1%] presented without symptoms attributable to their thymoma. Histologic review disclosed 12[36.4%] epithelial thymoma, 10[30.3%] mixed lymphoepithelial, 9[27.3%] lymphocytic, 1[3.0%] spindle cell and 1[3.0%] unknown cell thymoma. They were classified according to Masaoka`s clinical staging criteria; by these criteria, 8 patients were stage I, 5 patients were stage II, 15 patients were stage III and 3 patients were stage IV. Total excision of mass was possible in 20 patients. Partial excision of mass in 4 patients and biopsy in 7 patients were carried out during the operation. There was only one operation mortality. Follow-up was possible in 26 patients and follow-up ranged from 4 months to 10.5 years[mean 28.9 months]. One-year survival rates were 77.8% and eight patients expired during follow-up period. Eleven[78.6%] patients with myasthenia gravis were improved after the operation. This observation suggests that the most significant factor determining the survival is whether or not total surgical excision had been performed.

• Journal of Society of Preventive Korean Medicine
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• v.5 no.1
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• pp.10-30
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• 2001

Oriental medicine needs to be armed with theories on health-improvement concept under it and basic data matching its views, in order to participate in the health-improvement service in industrial work places. The Orient medicine health-improvement program defines factors that determine individuals' lifestyle, and provides information and technologies for workers to practice in life. To that end, this research compares and analyzes health-improvement concept and health care, defines relations between individuals' health state and their lifestyle as the basic data needed to perform health-improvement business for workers. 1. The subjects employed for this research is categorized into; by gender, males 52.1% and females 47.9% with no big difference between them; and by age, 20s, 6.1%, 30s. 33.9%, 40s, 34.1%, and 50s, 24.8% with 30-50 accounting for most of it. By marriage status, unmarried represents 7.1%, and married 79.1% with most of them married; by revenue, under one million won represents 3.0%, 1-2 million won 26.4%, 2-2.49 million won 11.2%, above 2.5 million won 11.2%, and 1-2.5 million won a majority. By living location, owned houses represents 65.4%, rented houses 14.7%, monthly-rented 9.5%; and by education, elementary and middle school represent 16.9%, high school and its dropouts 22.6%, and junior college and higher 51.6%, with high school and higher occupying most of the group. 2. By job, office workers and managerial workers represent 12.3%, part-timers 21.0%, manual workers 11.4%, jobless 0.6%, professionals 35.6%, service 0.6%, housewives 8.4%, and equipment/machinery operation/assemblers 10.1%. Of this, jobless and part-timers, totaling three, are dropped from this research. By years worked, 0-3.9 years represents 9.7%, 4-7.9 years 6.7%, 8-14.9 years 18.4%, above 15 years 28.7%, and no respondents 36.5%. 3. The degree of the subjects practicing life-improvement lifestyle, on a scale of 1 to 4, is an average of 2.69, personal relations 3.04, self-realization 2.92, stress management 2.76, nutritional state 2.73, responsibility for health 2.47, and athletic activities 2.18, with personal relations earning the highest points and athletic activities the lowest. As for factors influencing health-improvement lifestyle, there is no significant difference between gender, age, and marriage status. Meanwhile, there is significant difference between revenue, dwelling pattern, education level, etc. That is, higher income-bracket, owned houses, rented houses, monthly-rented houses, and higher-educated, in this order, show higher average in health-enhancement lifestyle. By job, housewives, manual workers, office workers, professionals, equipment/ machinery operation/ assemblers, and part-timers, in this order show higher points, while there is no difference with significance by years worked. 4. Factors that affect health-improvement lifestyle are shown below. Self-realization is influenced by age, marriage status, type of dwellings, and level of education; responsibility for health by type of dwellings; athletic activities by gender and age; nutrition by age, marriage status and type of dwellings; personal relations by marriage status; and stress management by type of dwellings. 5. Areas with high points by job show this: in self-realization, office workers, manual workers, housewives, professionals, equipment/ machinery operation/ assemblers, in this order, show difference with significance; in the area of responsibility for health, manual workers, housewives, equipment/ machinery operation/ assemblers, professionals, office workers and part-timers, in this order, do. In athletic activities, manual workers, housewives, office workers, professionals, equipment/ machinery operation/ assemblers, and part-timers, in this order, show difference with significance; in nutrition, housewives, office workers, manual workers, professionals, equipment/ machinery operation/ assemblers, and part-timers, in this order do; and in stress, housewives, office workers, manual workers, professionals, equipment/ machinery operation/ assemblers, part-timers, in this order do. By years worked, more years showed higher points in the area of responsibility for health and nutrition; in the area of athletic activities, above 15 years, 4-8 years, below 4 years and 8-14 years, in this order, show higher points; and no difference shows in realization, personal relation, and stress area. 6. To look at correlation between overall and divisional health-improvement practice degree, this researcher has analyzed it using Person's correlation coefficient. Self-realization, responsibility for health, athletic activities, nutrition, support for personal relations, and stress management show significant correlation with the sub-divisions, while all health-improvement lifestyle shows significant correlation with the six sub-divisions.

• Journal of Korean Neurosurgical Society
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• v.50 no.4
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• pp.381-384
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• 2011

The authors report a case of atypical extraventricular neurocytoma (EVN) transformed from EVN which had been initially diagnosed as an oligodendroglioma 15 years ago. An 8-year-old boy underwent a surgical resection for a right frontal mass which was initially diagnosed as oligodendroglioma. When the tumor recurred 15 years later, a secondary operation was performed, followed by salvage gamma knife treatment. The recurrent tumor was diagnosed as an atypical EVN. The initial specimen was reviewed and immunohistochemistry revealed a strong positivity for synaptophysin. The diagnosis of the initial tumor was revised as an EVN. The patient maintained a stable disease state for 15 years after the first operation, and was followed up for one year without any complications or disease progression after the second operation. We diagnosed an atypical extraventricular neurocytoma transformed from EVN which had been initially diagnosed as an oligodendroglioma 15 years earlier. We emphasize that EVN should be included in the differential diagnosis of oligodendroglioma.

• Advances in pediatric surgery
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• v.14 no.1
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• pp.58-66
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• 2008

Untreated cryptorchidism contributes to infertility and may play a role in increasing the risk of malignancy. The appropriate time of operation was considered before school age in 1970s, 2 years of age in 1980s, and between 1 and 2 years of age from 1990s to present time. Orchiopexy is the most common operation for congenital urological problem of children. We analyze our experience of orchiopexies to evaluate the results and to identify the role of the pediatric surgeon. We reviewed the medical records of 91 patients who underwent orchiopexy from January 1996 to December 2007. The patient age at orchiopexy were as follows: 48 cases (52.7 %) under 2 years of age, 24 cases (26.4 %) between 3 and 5 years, 16 cases (17.6 %) between 6 and 10 years, and 3 cases (3.3 %) over 11 years. Location of testes was preperitoneum in all 91 cases. There were 84 unilateral and 7 bilateral cases. Among the unilateral cases, the undescended testes were on right side in 54 cases and on the left side in 30 cases. The surgical procedure employed in all cases was trans-inguinal orchiopexies. Seventy-nine patients had excellent results. There were 12 complications; 5 cases of wound infection and 7 cases of temporary incomplete descent. Seven cases of incomplete descent have become normal from 3 to 6 months after orchiopexy. According to our results, 43 cases (47.3 %) underwent orchiopexies over 2 years of age. In conclusion, orchiopexies were successful in most cases of cryptorchidism in terms of testicular position and growth. We suggest that pediatric surgeons should educate their primary care physicians and parents concerning the potential complications of cryptorchidism and the appropriate time of operation.

• Speech Sciences
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• v.14 no.4
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• pp.203-212
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• 2007

This study was to compare some acoustic characteristics of vowels produced by children with cochlear implant (CI) and the children with normal hearing. 20 subjects under ten years old were further classified into two groups (one group of CI children under four years old and the other group of CI children over four years old). For the normal hearing group, 20 subjects are participated in the experiment. Some acoustic parameters including fundamental frequency (F0) and formant frequencies (F1, F2) were measured in the two groups according to the age of cochlear implant operation. For the CI group, three comer vowels (/a/, /i/, /u/) were recorded five times in isolation and analyzed with Multi-Speech (Kay Elemetrics, model 3700), and two independent t-tests on their formant data were conducted using SPSS 11.5. The result showed that the implanted group over four years had a significant difference in F0 and F1 comparing with the implanted group under four years of age as well as the normal hearing group. Those values of the children with the implanted group under four years old were closer to those of the children with the normal hearing. As to the F2, there was no significant difference among implanted groups. However, it was shown that the vowel space for the implanted groups regardless the operation age indicated much smaller than that for the normal hearing children. This acoustic results suggest that CI surgery would be much more effective if it is done under the age of four years old.

• Journal of Chest Surgery
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• v.23 no.4
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• pp.731-735
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• 1990

Simultaneous and non simultaneous bilateral spontaneous pneumothorax patients[273] were reviewed retrospectively from April 1986 to March 1990 in the Dept. of Thoracic and Cardiovascular Surgery, Kyung Hee University Medical College. The incidence of bilateral spontaneous pneumothorax was 13.6%[37] and sexual distribution was male dominant [Male:33, Female:4]. The patients were classified into three major groups according to therapeutic methods: Group I [7]; who were treated with simultaneous bilateral operation for unilateral recurred spontaneous pneumothorax through median sternotomy. Mean age was 20.7 years[17 \ulcorner28] and follow up duration was 7.7 months [3 weeks \ulcorner2 years]. Group II [23];who were treated with staged lateral thoractomy, unilateral thoracotomy and non simultaneous contralateral closed thoracostomy, or simultaneous or non simultaneous bilateral closed thoracostomy. Mean age was 28.6 years [17 \ulcorner56] and follow up duration was 9.8 months[one week \ulcorner3.5 years]. Group III[10] ;who were treated with simultaneous bilateral operation for simultaneous or non simultaneous bilateral spontaneous pneumothorax through median sternotomy. Mean age was 21.4 years[17 \ulcorner28] and follow up duration was 12.8 months[2 weeks \ulcorner2.7 years]. Among the patients managed through median sternotomy simultaneously [Group I and III], there were visible blebs or bullous changed lesions mainly in the apicoposterior segment bilaterally in 15 patients[88.2%] Postoperative complications were 3 cases in Group II [wound infection:2 cases, temporary left wrist drop: one case] but none in Group I and III. Spontaneous pneumothorax recurred in 2 cases, one in Group II and another in Group III but none in Group I. 12 cases of 94 patients[12.8%o] who were treated with unilateral thoracotomy needed contralateral thoracotomy mean 14.9 months[7.5 \ulcorner 25 months] later. Mean age was 20.9 years [17 \ulcorner28]. In conclusion, simultaneous bilateral operation through median sternotomy should be considered in managements of spontaneous pneumothorax, especially in late teens and early twenties except young women for cosmetic reasons.

• Journal of Chest Surgery
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• v.24 no.10
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• pp.979-986
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• 1991

From October 1988 to November 1989, seven patients underwent valve replacement during the active phase of native valve endocarditis. There were 4 males and 3 females whose mean age was 41 years[range, 16 to 68 years]. Preoperative two-dimensional and Doppler echocardiography showed vegetations and severe valvular regurgitation in all patients. Blood cultures were positive in 4, and negative in 3 patients Organisms were alpha-hemolytic Streptococcus in 2, Staphylococcus epidermidis in 1, Erysipelothrix rhusiopathiae in 1 patient Valve tissue cultures were negative in all patients. Intravenous antibiotic therapy had been done for 3 to 18 days in 5 patients pre-operatively and was not done in 2 patients, Indications for operation were heart failure in h, and systemic emboli in 1 patient. The aortic valve was involved in 3, mitral in 1, and both aortic and mitral in 3 patients, One operative death[14.4%] occurred in patient with cardiogenic shock before operation. Late death occurred in one on 14 months after operation. The remaining 5 patients were followed up over a two year period in good condition. In conclusion, native valve endocarditis with severe heart failure must be considered for early operation.