• Journal of Chest Surgery
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• v.44 no.2
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• pp.169-177
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• 2011

Background: Video-assisted thoracic surgery (VATS) lobectomy has been performed with increasing frequency over the last decade. However, there is still controversy as to its indications, safety, and feasibility. Especially regarding lung cancer surgery, it is not certain whether it can reduce local recurrences and improve overall survival. Materials and Methods: We retrospectively reviewed 1,067 cases of VATS lobectomy performed between 2003 and 2009, including the indications, postoperative morbidity, mortality, recurrence, and survival rate. Results: One thousand and sixty seven patients underwent VATS lobectomy for the following indications: non-small cell lung cancer (NSCLC) (n=832), carcinoid tumors (n=12), metastatic lung cancer (n=48), and benign or other diseases (n=175). There were 63 cases (5.9%) of conversion to open thoracotomy during VATS lobectomy. One hundred thirty one (15.7%) of the 832 NSCLC patients experienced pathologic upstaging postoperatively. The hospital mortality rate was 0.84% (9 patients), and all of them died of acute respiratory distress syndrome. One hundred forty-nine patients (14.0%) experienced postoperative complications. The median follow-up was 22.9 months for patients with NSCLC. During follow-up, 120 patients had a recurrence and 55 patients died. For patients with pathologic stage I, the overall survival rate and disease-free survival rate at 3 years was $92.2{\pm}1.5%$ and $86.2{\pm}1.9%$, respectively. For patients with pathologic stage II disease, the overall survival rate and disease-free survival rate at 3 years was $79.2{\pm}6.5%$ and $61.9{\pm}6.6%$, respectively. Conclusion: Our results suggest that VATS lobectomy is a technically feasible and safe operation, which can be applied to various lung diseases. In patients with early-stage lung cancer, excellent survival can be also achieved.

• Tuberculosis and Respiratory Diseases
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• v.39 no.5
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• pp.425-432
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• 1992

Background: The prevalence of tuberculosis in Korea decreased remarkably for the past 30 years, while for at least the recent 10 years, the frequency of disease attributable to mycobacteria other than tuberculosis (MOTT) began to increase both in actual numbers and in the proportion of the total burden of mycobacterioses. Method: Twenty nine cases, diagnosed as having pulmonary disease due to MOTT on the basis of repeated isolations of the relevant organisms from sputum specimens and chest X-ray findings from Jan. 1982 throught Dec. 1991 at the Chest Clinic of the Korean Institute of Tuberculosis, were reviewed in terms of clinical features and courses. Results: 1) Nineteen cases (66%) were infected with Mycobacterium avium-intracellulare, 5 cases (17%) with M. fortuitum, 4 cases (14%) with M. chelonei, and 1 cases (3%) with M. szulgai. 2) The ratio of male versus female patients was 1.9:1. 3) The peak incidence was in the fifth decade. 4) Eighteen cases (62%) had moderately advanced disease and 11 cases (38%) had far advanced disease on chest P-A film. 5) The common symptoms were cough (59%), sputum (52%), and dyspnea (34%). 6) All cases had a previous history of tuberculosis. 7) Most of the isolates were highly resistant to the major antituberculosis drugs and 48~52% showed a sensitivity to cycloserine, kanamycin or enviomycin. 8) Of 19 cases which were treated and followed-up for over 12 months, 3 cases attained negative conversion on cultures (2 M. fortuitum infections, 1 M. szulgai infection). Sixteen cases failed in attaining negative conversion on cultures. However, their clinical courses were chronic and indolent despite of persistant culture positivity. Conclusion: Treatment of these patients has been difficult because of the frequency of severe underlying conditions and the natural resistance of most of the nontuberculous mycobacteria to the presently available drugs.

• Korean Journal of Community Nutrition
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• v.14 no.5
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• pp.565-575
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• 2009

The purpose of this study was to propose the appropriate sizes and dish combination for nutritional-balanced lunch boxes delivered to children under the government-funded meal service program in Korea. The study was based on the 3 : 1 : 2 Meal Box Magic, a nutrition education method developed in Japan. A total of 290 lunch menus, comprising of 10 day menus from 29 organizations having delivered lunch boxes to children during summer vacation of 2008, were analyzed and used as the base data for lunch box combination. Dishes of the menus were classified into 6 groups: Rice group, Protein side dish group (including meat, fish, egg, and bean dishes), Vegetable side dish group, Kimchi group (including kimchi and jangajji), Soup stew group, and the other group. Nutrient analysis was conducted for 100 ml of these dishes by CAN Pro 3.0 utilizing volume and weight conversion data used for analysis of the Korea Health and Nutrition Examination Survey and those from the Nutrient Composition of Food for Consumers. All the possible combinations of 5 dishes, comprising of 3 dishes from Rice group, Protein side dish group, and Kimchi group, respectively, and 2 dishes from Vegetable side dish group, were made using the frequently served dishes from the respective dish group. Nutrient analysis of each combination was conducted based on the assumption that a lunch box was 600 ml and filled up to 80% by dishes using the volume ratio of 3 : 1 : 1.5 : 0.5 for Rice group : Protein side dish group : Vegetable side dish group : Kimchi group. The mean and standard deviation of energy and nutrients of all combinations calculated by weighting the serving frequency of each dish selected for the combinations were $621\pm81$ kcal for Energy, $22.1\pm5.0$ g for Protein, $120\pm45$ mg for Calcium, $4.1\pm1.1$ mg for Iron, $201\pm130\;{\mu}g$ RE for Vitamin A, $0.34\pm0.10$ mg for Thiamin, $0.27\pm0.10$ mg for Riboflavin, and $24.3\pm9.6$ mg for Vitamin C. The energy percentages from Carbohydrate, Protein and Fat were 66%, 14% and 20%. The analysis results met the nutrition standard of lunch boxes for male elementary students in grades 4 through 6 under the government-funded meal service program regarding calories, nutrients except calcium and riboflavin, and macronutrient distribution ranges. Accordingly appropriate box sizes were suggested for different age and sex groups to meet the respective nutrition standards. In addition, milk or dairy products were suggested to accompany lunch boxes to supplement calcium and riboflavin intake. The method of selecting box sizes and making dish combination suggested in this study could be useful for the organizations preparing lunch boxes under the government-funded children's meal service program where nutrition professionals are not available.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.6
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• pp.117-125
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• 2007

Recently, a fuel cell with low voltage and high current output characteristics is remarkable for new generation system. It needs both a DC-DC step-up converter and DC-AC inverter to be used in fuel cell generation system. Therefor, this paper, consists of an isolated DC-DC converter to boost the fuel cell voltage 380[VDC] and a PWM inverter with LC filter to convent the DC voltage to single-phase 220[VAC]. Expressly, The fuel cell system which it proposes DC-DC the efficient converter used PWM the phase transient control law and it depended to portion resonance ZVS switching, loss peek voltage and electric current of realization under make schedule, switching frequency anger and the switch reduction. And mind benevolence it sprouted 2 in stop circuit and it added and a direct current voltage and the electric current where the ingredient is reduced in load side ripple stable under make whom it will be able to supply. Besides the efficiency of 92[%]is obtained over the wide output voltage regulation ranges and load variations. Also, under make over together the result leads simulation and test, the propriety confirmation.

• Journal of the Institute of Convergence Signal Processing
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• v.17 no.2
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• pp.83-92
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• 2016

In this paper, we introduce the results of the testing and observation systems for performance wideband expansion in the Korean VLBI Network(KVN). The KVN performs VLBI observations to 1024 Mbps data rate, and 8192 Mbps observing for four simultaneous observation is now evaluating for normal operation. The VLBI stations in several world countries developed their own wideband observing systems to observe the celestial objects with high precision and high resolution or are working with several countries. The KVN is planning to introduce a high-speed sampler, OCTAD, for sampling directly up to 2048 MHz bandwidth for RF signal of K/Q/W/D band in the frequency band without conversion. Therefore, as a preliminary study for the performance scalability of the KVN then through the close cooperation with National Astronomical Observatory of Japan (NAOJ), the OCTAD high-speed sampler and OCTADISK2 high-speed recorder were installed in the KVN Yonsei station, and verify the performance through a wideband.

• Journal of IKEEE
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• v.22 no.4
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• pp.1006-1011
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• 2018

This paper proposes a three level buck converter utilizing multi-bit flying capacitor voltage control. The conventional three-level buck converter can not control the flying capacitor voltage, so that the operation is unstable or the circuit for controlling the flying capacitor voltage can not be applied to the PWM mode. Also when the load current is increased, an error occurs in the inductor voltage. The proposed structure can control the flying capacitor voltage in PWM mode by using differential difference amplifier and common mode feedback circuit. In addition, this paper proposes a 3bit flying capacitor voltage control circuit to optimize the operation of the three level buck converter depending on the load current, and a triangular wave generation circuit using the schmitt trigger circuit. The proposed 3-level buck converter is designed in $0.18{\mu}m$ CMOS process and has an input voltage range of 2.7V~3.6V and an output voltage range of 0.7V~2.4V. The operating frequency is 2MHz, the load current range is 30mA to 500mA, and the output voltage ripple is measured up to 32.5mV. The measurement results show a maximum power conversion efficiency of 85% at a load current of 130 mA.

• Journal of Intelligence and Information Systems
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• v.27 no.2
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• pp.33-54
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• 2021

With the fourth industrial revolution and the arrival of the New Normal era due to Corona, the importance of Non-contact technologies such as artificial intelligence and big data research has been increasing. Convergent research is being conducted in earnest to keep up with these research trends, but not many studies have been conducted in the area of nuclear research using artificial intelligence and big data-related technologies such as natural language processing and text mining analysis. This study was conducted to confirm the applicability of data science analysis techniques to the field of nuclear research. Furthermore, the study of identifying trends in nuclear spent fuel recognition is critical in terms of being able to determine directions to nuclear industry policies and respond in advance to changes in industrial policies. For those reasons, this study conducted a media trend analysis of pyroprocessing, a spent nuclear fuel treatment technology. We objectively analyze changes in media perception of spent nuclear fuel dry treatment techniques by applying text mining analysis techniques. Text data specializing in Naver's web news articles, including the keywords "Pyroprocessing" and "Sodium Cooled Reactor," were collected through Python code to identify changes in perception over time. The analysis period was set from 2007 to 2020, when the first article was published, and detailed and multi-layered analysis of text data was carried out through analysis methods such as word cloud writing based on frequency analysis, TF-IDF and degree centrality calculation. Analysis of the frequency of the keyword showed that there was a change in media perception of spent nuclear fuel dry treatment technology in the mid-2010s, which was influenced by the Gyeongju earthquake in 2016 and the implementation of the new government's energy conversion policy in 2017. Therefore, trend analysis was conducted based on the corresponding time period, and word frequency analysis, TF-IDF, degree centrality values, and semantic network graphs were derived. Studies show that before the 2010s, media perception of spent nuclear fuel dry treatment technology was diplomatic and positive. However, over time, the frequency of keywords such as "safety", "reexamination", "disposal", and "disassembly" has increased, indicating that the sustainability of spent nuclear fuel dry treatment technology is being seriously considered. It was confirmed that social awareness also changed as spent nuclear fuel dry treatment technology, which was recognized as a political and diplomatic technology, became ambiguous due to changes in domestic policy. This means that domestic policy changes such as nuclear power policy have a greater impact on media perceptions than issues of "spent nuclear fuel processing technology" itself. This seems to be because nuclear policy is a socially more discussed and public-friendly topic than spent nuclear fuel. Therefore, in order to improve social awareness of spent nuclear fuel processing technology, it would be necessary to provide sufficient information about this, and linking it to nuclear policy issues would also be a good idea. In addition, the study highlighted the importance of social science research in nuclear power. It is necessary to apply the social sciences sector widely to the nuclear engineering sector, and considering national policy changes, we could confirm that the nuclear industry would be sustainable. However, this study has limitations that it has applied big data analysis methods only to detailed research areas such as "Pyroprocessing," a spent nuclear fuel dry processing technology. Furthermore, there was no clear basis for the cause of the change in social perception, and only news articles were analyzed to determine social perception. Considering future comments, it is expected that more reliable results will be produced and efficiently used in the field of nuclear policy research if a media trend analysis study on nuclear power is conducted. Recently, the development of uncontact-related technologies such as artificial intelligence and big data research is accelerating in the wake of the recent arrival of the New Normal era caused by corona. Convergence research is being conducted in earnest in various research fields to follow these research trends, but not many studies have been conducted in the nuclear field with artificial intelligence and big data-related technologies such as natural language processing and text mining analysis. The academic significance of this study is that it was possible to confirm the applicability of data science analysis technology in the field of nuclear research. Furthermore, due to the impact of current government energy policies such as nuclear power plant reductions, re-evaluation of spent fuel treatment technology research is undertaken, and key keyword analysis in the field can contribute to future research orientation. It is important to consider the views of others outside, not just the safety technology and engineering integrity of nuclear power, and further reconsider whether it is appropriate to discuss nuclear engineering technology internally. In addition, if multidisciplinary research on nuclear power is carried out, reasonable alternatives can be prepared to maintain the nuclear industry.