• 환경위생공학
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• 제23권4호
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• pp.73-82
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• 2008

In this study, a dry single-phase anaerobic digestion process (Dranco system) was investigated to evaluate the optimum operational conditions. Several factors such as injection rate of organic waste, biogas production, $CH_4$ content in the biogas, pH of the sludge, $NH_3$-N and VFA concentration were investigated based on the operation of the digestion process for 2 months (short term) and 8 months (long-term). The operation results showed that a small quantity of food waste should be injected every week and that a 10% increase of the microorganism injection rate should be needed. However, normal operation was conducted after 11 weeks based on the designed quantity. The $CH_4$ content in the biogas was high at the beginning and the end of the food injection. However, it was low during week days. When the biogas production was high, the $CH_4$ concentration was low. The biogas production increased with an increase of the injection rate. $100m^3$/ton of biogas was produced from normal operation of the digestion process based on the designed quantity. The pH values of the digestion tank based on short-term operation ranged from 8 to 8.5. However, the pH values ranged from 7.45 to 8.15 after 4 weeks of long-term operation. The $NH_3$-N concentration of short-term operation ranged from 4,500 to 5,500 ppm and it gradually decreased to 2,000ppm after normal operation was commenced. For long-term operation, it was 5,000ppm initially and 3,800ppm after normal operation was commenced. The VFA concentration of sludge was less than 900ppm and 2,500ppm for short and long-term operations, respectively, after normal operation. Overall, the differences between sludge pH, $NH_3$-N and VFA concentrations may be due to the different types of microorganisms and the digestion ability of the microorganisms which exist in the accumulation of non digested organics. Moreover, it may be also caused by the type of food waste. Further investigation is needed to confirm these relationships.

• 전기학회논문지
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• 제58권1호
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• pp.199-202
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• 2009

Scan design is currently the most widely used structured Design For Testability approach. In scan design, all storage elements are replaced with scan cells, which are then configured as one or more shift registers(also called scan chains) during the shift operation. As a result, all inputs to the combinational logic, including those driven by scan cells, can be controlled and all outputs from the combinational logic, including those driving scan cells, can be observed. The scan inserted design, called scan design, is operated in three modes: normal mode, shift mode, and capture mode. Circuit operations with associated clock cycles conducted in these three modes are referred to as normal operation, shift operation, and capture operation, respectively. In spite of these, scan design methodology has defects. They are power dissipation problem and test time during test application. We propose a new methodology about scan shift clock operation and present low power scan design and short test time.

• 한국임상수의학회지
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• 제18권2호
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• pp.124-132
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• 2001

The purpose of this study is to know whether single layer continuous connell suture is an acceptable alternative to simple interrupted approximating suture for end-to-end intestinal anastomosis in dogs. Fourteen mixed-breed dogs weighing 2 to 5 kg were allotted to group treated with simple interrupted approximating suture (Group I) and group treated with single layer continuous Connell suture (Group II), each of 7 dogs. All dogs in each suture pattern were compared with time for total operation ad suture elapsed for intestines to anastomose, clinical signs, changing of pre-and postoperative luminal size, status of feces, adhesion at anastomotic site for 14 days after operation. Time for total operation and suture time for intestinal anastomosis were none significant between Group I and Group II, although those in Group II was about 3 minutes shorter than those in Group I, respectively. Group I spent average 47.08${\pm}$11.10 minutes on total operation, 20.97${\pm}$5.54 minutes on suture time for intestinal anastomosis and Group II spent average 44.74${\pm}$7.77 minutes, 17.73${\pm}$3.05 minutes, respectively. All dogs were no special differences in vitality, vomiting, appetite between Group I and Group II for 14 days after operation. All dogs, except one dog in Group I, had showed normal vitality and appetite since 6~8 days after operation. Initial return of fecal passage showed in all dogs before 6 days after operation and thereafter most dogs showed normal feces. According to results, it was thought that all dogs with normal vitality and appetite before 8 days had showed good prognosis. There were no changes of intestinal luminal size in 2 dogs performed Group In and one dog performed Group II between at operation and 14 days after operation. Narrowing rate of intestinal lumen in Group I was average 9.3% of the normal diameter, whereas in Group II, 9.5% of normal diameter. In complications after operation, only one dog in Group I showed intestinal intussusception but the others didn't. Length of adhesion was measured between intestinal anastomotic site and omental graft. Length of adhesion in dogs performed Group II was mostly shorter than that of Group I. Adhesion with proximate intestines occurred in five dogs, which consisted of 3 dogs performed Group I and 2 dogs performed Group II. Concurrently, they had a great length of adhesion between anastomotic site and omental graft. There were no great differences between Group I and Group II about speed of operation, clinical signs, complications such as leakage and stricture. And all dogs performed intestinal anastomosis showed good clinical condition and prognosis. In conclusion, Single layer continuous Connell suture can safely perform an intestinal anastomosis and be an alternative of simple interrupted approximating suture in aspect of speed clinically.

• 한국재난정보학회 논문집
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• 제18권1호
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• pp.80-90
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• 2022

연구목적: 본 연구는 고속철도와 도시철도 장대터널 계측기기의 정상 작동율 현황을 조사하고 분석하여 장대터널에서 스마트계측과 계측관리 기술을 향상시키고자 한다. 연구방법: 고속철도 장대터널 3개 노선인 수서평택선, 경부선, 호남선과 도시철도 장대터널 2개 노선인 서울도시철도 5,6,7호선과 9호선을 대상으로 장대터널별 6-8종류의 계측기기에 대하여 정상 작동율을 조사하고 분석하여 상호 비교를 실시한다. 연구결과: 계측기기의 정상 작동이 높은 순서는 수서평택고속철도 92.1%, 서울도시철도 5,6,7호선 85.8%, 서울도시철도 9호선 85.2%, 경부고속철도 80.5%, 호남고속철도 46.7%로 나타났다. 결론: 3개 고속철도 장대터널 계측기기의 정상 작동율 평균은 83.4%이며, 2개 도시철도 장대터널 평균은 85.5%를 보여 편차는 크지 않는 것으로 나타났으며, 고속철도와 도시철도 5개 노선의 장대터널 계측기기의 정상 작동율 평균은 84.2%를 보였다.

• Nuclear Engineering and Technology
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• 제54권2호
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• pp.644-652
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• 2022

During the pyroprocessing operation, various signals can be collected by process monitoring (PM). These signals are utilized to diagnose process states. In this study, feasibility of using PM for nuclear safeguards of electrorefining operation was examined based on the use of machine learning for detecting off-normal operations. The off-normal operation, in this study, is defined as co-deposition of key elements through reduction on cathode. The monitored process signal selected for PM was cathode potential. The necessary data were produced through electrodeposition experiments in a laboratory molten salt system. Model-based cathodic surface area data were also generated and used to support model development. Computer models for classification were developed using a series of recurrent neural network architectures. The concept of transfer learning was also employed by combining pre-training and fine-tuning to minimize data requirement for training. The resulting models were found to classify the normal and the off-normal operation states with a 95% accuracy. With the availability of more process data, the approach is expected to have higher reliability.

• 한국위성정보통신학회논문지
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• 제8권2호
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• pp.80-87
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• 2013

통신, 해양, 기상의 세 분야 복합 임무를 수행하는 천리안위성(Communication Ocean Meteorological Satellite: COMS)은 정지궤도 동경 $128.2{\circ}$에서 2011년 4월부터 현재 정상 운영 임무를 수행하고 있다. 세 임무를 수행하기 위해 천리안위성에는 3가지 탑재체인 기상탑재체(Meteorological Imager: MI), 해양탑재체(Geostationary Ocean Color Imager: GOCI), 통신탑재체(Ka-band communication payload)가 실려 있다. 세 가지 임무 운영과 위성 유지 관리를 위해 위성 관제가 실시간 운영으로 수행된다. 위성 실시간 운영은 명령과 원격측정자료를 통해 위성과 직접 통신하는 업무이다. 본 논문에서는 천리안위성의 실시간 운영 특성으로 지상국 장비 구성과 일일, 주간, 월간, 계절별, 연간 운영 업무 특성을 논하였다. 천리안위성의 궤도상 시험(In-Orbit-Test: IOT) 말기와 정상 운영 첫 해가 포함되는 2011년의 1년간 운영 결과에 대한 토의를 통해 성공적인 실시간 운영 결과 확인도 제시하였다.

• Journal of Chest Surgery
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• 제18권4호
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• pp.679-691
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• 1985

Ninety patients underwent mitral valvular heart surgery associated with or without aortic valve surgery and subjected to a clinical study in relation to their control of postoperative atrial fibrillation. There were 26 males and 64 females ranged in age from 16 to 56 years with a mean of 35.2 years. Systemic arterial embolizations were observed in 11 patients [12.2%]. Four patients of them were in normal sinus rhythm and 7 in atrial fibrillation. Out of these, left atrial thrombi were found only in 2 at the operation. Intraoperatively confirmed left atrial thrombi were in 16 patients [17.7%] of all 90 patients: Eleven patients occurred at the age of more than 40 years, 14 were in atrial fibrillation and 2 only had previous episodes of systemic arterial embolization. Sixty three patients underwent isolated mitral valve surgery [OMC 28, MVR 35] and 27 patients associated with aortic valve surgery along with mitral valve [OMC+AVR 13, MVR+AVR 14]. Preoperatively, 44 patients [48.9%] were in normal sinus rhythm. Of them, 35 patients [79.5%] revealed normal sinus rhythm thoroughly after operation without any aid of digitalis or quinidine and 5 patients [11.4%] restored normal sinus rhythm with digitalization alone. Other 3 patients converted to normal sinus rhythm with the addition of quinidine, however, in 1 patient who was resistant to quinidine therapy, electrocardioversion was carried out on the postoperative third week showing normal sinus rhythm. Thus, the most atrial fibrillations that occurred for the first time in the postoperative period, were able to reverted to normal sinus rhythm responding well to antiarrhythmic therapy. Preoperatively, 46 patients [51.1%] were in atrial fibrillation. Of them, only 5 patients returned to sinus rhythm after operation without any aid of digitalis or quinidine and other 5 restored normal sinus rhythm with digitalization: namely 2 restored within early postoperative period and 3 after more than 3 months. Eight patients well responded to quinidine therapy showing normal Sinus rhythm. So far, 25 patients have remained in persistent atrial fibrillation on 6 to 36 months follow-up. In view of these, 17 patients [68%] were over 40 years of age, 22[80%] had long duration of symptom over 5 years and 10[40%] have had atrial thrombi before operation. Left atrial dimension were still more than 40mm in 21 patients on follow up M-mode echocardiogram. One month after operation, 87 hospital survivors were improved by at least one functional NYHA class. There were 3 operative deaths [3.3%, bleeding 1, LCOS 2] and 4 late deaths [LCOS 1, valve thrombosis 1, late bleeding 1, fulminant hepatitis 1] during follow-up period. According to our limited experience, we may conclude that better results will be expected with the addition of quinidine therapy judiciously in the cases of postoperative persistent atrial fibrillation who were aged or had longer history of symptom and left atrial thrombi.

• Nuclear Engineering and Technology
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• 제54권8호
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• pp.2840-2851
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• 2022

Electric boilers (EBs) are the backup steam source for the auxiliary steam system of high-temperature gas-cooled reactor nuclear power plants. When the plant is in normal operations, the EB is always in hot standby status. However, the current hot standby operation strategy has problems of slow response, high power consumption, and long operation time. To solve these problems, this study focuses on the optimization of hot standby operations for the EB system. First, mathematical models of an electrode immersion EB and its accompanying deaerator were established. Then, a control simulation platform of the EB system was developed in MATLAB/Simulink implementing the established mathematical models and corresponding control systems. Finally, two optimization strategies for the EB hot standby operation were proposed, followed by dynamic simulations of the EB system transient from hot standby to normal operations. The results indicate that the proposed optimization strategies can significantly speed up the transient response of the EB system from hot standby to normal operations and reduce the power consumption in hot standby operations, improving the dynamic performance and economy of the system.

• Journal of Chest Surgery
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• 제15권4호
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• pp.460-466
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• 1982

A analysis of CPK & LDH Isoenzyme was done on the consecutive patients undergoing thoracic operations from July 1982 to October 1982 in the Department of Thoracic and Cardiovascular Surgery, Capital Armed Forces General Hospital. Eighteen patients were analysed by three groups, such as open heart surgery [group A], major thoracic operation [group B] , minor thoracic operation group [group C]. In all patients serial determination of total level and Isoenzyme of CPK, LDH wad done on preoperative operative and up to 8th post-operative day, The results obtained are as follows. 1. The average value of serum CPK before the operation was 61 IU/L. The value of serum CPK was increased following the operation mainly MM portion and reached to the maximal level of 536107 IU/L in A group 1200191 IU/L in B group, 306150 IU/L in C group on the first postoperative day. The enzyme activity was gradually decreased thereafter and returned to the normal range on the 3rd or 4th day after the operation. 2. The average value of serum LDH before the operation was found to be 83 IU/L. The value was increased during the operation and reached to the maximal level of 481108 IU/L in group A, 14827 I U/L in group B, 10035 IU/L in group C on the second day after the operation. The enzyme activity was gradually decreased thereafter and returned to the normal range on the seventh day after the operation. The enzyme activity was dependent to the duration of operation, severity of muscle damage, type of thoracotomy, effect of extracorporeal circulation, state of disease.

• 말소리와 음성과학
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• 제3권3호
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• pp.157-165
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• 2011

This study investigated speech rate and intonation slope (least square method; F0, quarter-tone) in normal and CI children's utterances. Each group consisted of 12 people and were divided into groups of children with CI operation (before 3;00), children with CI operation (after 3;00), and normal children. Materials are composed of four kinds of grammatical dialogue sentences which are lacking in respect. Given three groups as independent variables and both speech rate and intonation slope as dependent variables, a one-way ANOVA showed that normal children had faster speech rates and steeper intonation slopes than those of the CI group. More specifically, there was a statistically significant speech rate difference between normal and CI children in all of the sentential patterns but imperative form (p<.01). Additionally, F0 and qtone slope observed in sentential final word showed a significant statistical difference between normal and CI children in imperative form (f0: p<.01; q-tone: p<.05).