• The KSFM Journal of Fluid Machinery
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• v.15 no.6
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• pp.70-76
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• 2012

Recently, because people are taking a great interest in the water supply system and the related facilities are getting larger, the surge suppression is very important problem. The waterhammer occurs when the pumps are started or stoped for operation or tripped due to the power failure. As the waterhammer problems as a result of the pump power failure were very serious, these situations were carefully investigated. Accordingly, we carried out both numerical simulations and field tests to confirm the safety of Juam intake pumping station in which had the in-line pumps. In this paper, it was reviewed that the water supply system has the reliability on the pressure surge, in case the air chambers were installed at both the inlet and the oulet of the in-line pumping station. From the numerical simulations, we found that negative pressure occurred at the inlet disappeared and high pressure occurred at the outlet reduced due to the air chambers. And these results of numerical simulations verified by the field tests. The field tests carried out in case of normal start, normal stop, one and two of pumps emergency stop. By results of simulations and field tests, we are sure that Juam intake pumping station in which have the air chambers is safe for the waterhammer. In addition, we suggested the operation methods of facilities for safe maintenance of the pumping station.

• Journal of Chest Surgery
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• v.29 no.1
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• pp.86-89
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• 1996

This is a report of successful conversion arterial switch operation for failed Sunning procedure in transposition of the great arteries(TGA) with ventricular septal defect(VSD). A 15 month-male patient was admitted due to intractable congestive heart failure after Sunning operation was done at the age of 8 months. Angiography revealed marked dysfunction of the morphologic right ventricle with tricuspid regurgitation and residual VSD. The pulmonary ventricle 1 systemic ventricle pressure ratio' of 75/85 at catheter study enabled us to do the take down of denning repair, patch closure of VSD and arterial switch without pulmonary artery banding. After the operation, the baby showed good growth with normal ventricular function.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.601-603
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• 2004

Multi-Spectral Camera(MSC) is a payload on the KOMPSAT -2 satellite to perform the earth remote sensing. The instrument images the earth using a push-broom motion with a swath width of 15 km and a ground sample distance (GSD) of 1 m over the entire field of view (FOV) at altitude 685 Km. The instrument is designed to have an on-orbit operation duty cycle of $20\%$ over the mission lifetime of 3 years with the functions of programmable gain! offset and onboard image data compression/storage. MSC instrument has one(1) channel for panchromatic Imaging and four(4) channel for multi-spectral Imaging covering the spectral range from 450nm to 900nm using TDI CCD Focal Plane Array (FPA). In this paper, the configuration, the interface of MSC hardware and the MSC operation concept are described. And the method of the MSC calibration are described and the design of MSC calibration operation to measure the change of MSC after Launch & Early Operation(LEOP) and normal mission operations are discussed and analyzed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.119-120
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• 2020

In order to establish an evaluation method that can quantitatively evaluate the fire safety of existing buildings in Korea, a stochastic approach is needed to consider the extent of damage in the event of actual fire, along with the operation and installation of facilities. Accordingly, as a basic study for the establishment of fire safety assessment methods for buildings, this study aims to analyze the results of safety inspection and the degree of damage caused by the operation of fire doors and fire shutters in order to derive the reliability of fire doors and fire shutters. As a result, the results of inspection of fire shutters and fire doors and the results of operation using fire statisticians are as follows. As a result of the inspection, the positive rate of fire doors was about 82% and 98% of normal operation was derived from the fire investigation.

• Archives of Plastic Surgery
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• v.34 no.6
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• pp.741-747
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• 2007

Purpose: In order to determine the differences in speech outcome based on timing of operation in submucous cleft palate, we have reviewed our experiences in the Furlow palatoplasty over the last 11 years. Methods: From March 1996 to March 2006, 38 submucous cleft palate patients received Furlow palatoplasty. 10 developmentally delayed patients were excluded and 5 patients were lost to follow up. The rest 23 patients were reviewed. Speech was evaluated preoperatively and postoperatively, and speech therapy was performed accordingly. Perceptual speech assessment included hypernasality, nasal emission and articulation disorder. Cinefluorography was performed to aid perceptual assessment. Based on timing of operation, the patients were divided into 3 groups as following: Group A under 24 months(8 patients), Group B from 25 to 48 months(6 patients), and Group C over 49 months (9 patients). Except 1 patient under speech therapy yet, resultant speech was compared. 200707Results: The rate of abnormal speech was higher in Group C(3/9, 33.3%) than in Group A(0%) or B(0%). All 3 patients who had been discontinued of speech therapy from the parent's judgment had abnormal speech. The reason for the discontinuation was that the regular speech therapy was a burden at school age. Any patients who had continued speech therapy had normal speech. Conclusion: The results of our study shows that operative timing is associated with speech development. Maintenance of speech therapy was an important factor for normal speech development. It will be helpful to perform a palatoplasty before 48 months of age to complete speech therapy before the school age.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.5
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• pp.923-930
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• 2020

In modern society, various DC power supplies are required to operate the system circuits of various electric devices. A stable DC supply is essential for the normal operation of the circuit and the importance of the converter for this is very high. This study proposed a PWM DC-DC converter circuit that applied a 3-pole 2-zero voltage controller to a KY converter, a step-up DC-DC converter, to maintain a stable supply of output voltage regardless of load fluctuations. In order to prove the normal operation characteristics of the proposed converter circuit, a PSIM simulation and a circuit operation experiment on the PCB board were performed in comparison with the conventional converter circuit.

• Journal of Astronomy and Space Sciences
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• v.27 no.3
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• pp.253-262
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• 2010

The electrical power system (EPS) of Korean satellites in low-earth-orbit is designed to achieve energy balance based on a one-orbit mission scenario. This means that the battery has to be fully charged at the end of a one-orbit mission. To provide the maximum solar array (SA) power generation, the peak power tracking (PPT) method has been developed for a spacecraft power system. The PPT is operated by a software algorithm, which tracks the peak power of the SA and ensures the battery is fully charged in one orbit. The EPS should be designed to avoid the stress of electronics in order to handle the main bus power from the SA power. This paper summarizes the results of energy balance to achieve optimal power sizing and the actual trend analysis of EPS performance in orbit. It describes the results of required power for the satellite operation in the worst power conditions at the end-of-life, the methods and input data used in the energy balance, and the case study of energy balance analyses for the normal operation in orbit. Both 10:35 AM and 10:50 AM crossing times are considered, so the power performance in each case is analyzed with the satellite roll maneuver according to the payload operation concept. In addition, the data transmission to the Korea Ground Station during eclipse is investigated at the local-time-ascending-node of 11:00 AM to assess the greatest battery depth-of-discharge in normal operation.

• Journal of the Korea Society of Computer and Information
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• v.13 no.4
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• pp.87-95
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• 2008

In this paper, we developed a selectable observation Point test architecture and test procedure for clocked 4-bit synchronous counter circuit based on boundary scan architecture. To develope, we analyze the operation of Sample/Preload instruction on boundary scan architecture. The Sample/Preload instruction make Possible to snapshot of outputs of CUT(circuit under test) at the specific time. But the changes of output of CUT during normal operation are not possible to observe using Sample/Preload in typical scan architecture. We suggested a selectable observation point test architecture that allows to select output of CUT and to observe of the changes of selected output of CUT during normal operation. The suggested a selectable observation point test architecture and test procedure is simulated by Altera Max 10.0. The simulation results of 4-bit counter shows the accurate operation and effectiveness of the proposed test architecture and procedure.

• Journal of Chest Surgery
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• v.18 no.1
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• pp.104-110
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• 1985

The anomalous systemic arterial supply to the lung without sequestration is an uncommon congenital anomaly characterized by the presence of a part of lung tissue which supplied by an aberrant artery from the aorta or its branch and normal communication with the normal bronchial tree, and it was reported by Huber in 1777 first. It differs from bronchopulmonary sequestration in having normal bronchial communication from the remainder lung and normal lung histology. We experienced a case of anomalous systemic arterial supply to the lung without sequestration, which was confirmed preoperatively. The patient was 16 year old male and came to us with complaints of mild fever and profuse sputum with coughing. Chest film showed a ring-like soft tissue shadow in Rt. middle lung field. Aortogram revealed an aberrant artery originated from abdominal aorta at 12th thoracic vertebral level and supplying a part of Rt. lower lobe of lung. At. the time of operation, an aberrant systemic artery which originated from the abdominal aorta supplying the Rt. lower lobe was noted, and the bronchial communications were normal. After division and ligation of the aberrant artery, Rt. lower lobectomy was performed The postoperative courses were uneventful and the patient was discharged with good condition.

• The Journal of Economics, Marketing and Management
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• v.7 no.1
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• pp.1-14
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• 2019

Purpose - Currently, the economic globalization has become a common channel for China's enterprise to perform the international economic activities. Due to this background, this paper tries to analyze the influence of internationalization level on operation performance of enterprises. Research design, data, and Methodology - This paper aims at 296 companies going listed in Shanghai Stock Exchange and Shenzhen Stock Exchange. The data about the listed companies during the 12 years from 2005 to 2016 have been collected. Relevant theories, including the theory of comparative advantage, monopolistic advantage and product life cycle in developed countries as well as the small scale technology and state on localized technological capacities in developing countries, have been summarized to provide theoretical basis for the influence of international operation on operation performance of the enterprises. Moreover, the current status of international operation of China's enterprises, including the dynamic cause of the internationalization of China's enterprises, its competitive advantage and disadvantage as well as the interest and potential risk of the internationalization, have been also analyzed. Results - Via adopting the panel data to conduct an empirical analysis, It can be found that the relationship between international operation level and operation performance of China's enterprises can be expressed as the S-curve of declining, rising and declining again. Conclusions - This paper has taken the lead in using Ohlson corporate value model to fill the gap in the relevant researches in China. It can also provide guidance for the international operation of China's enterprises. Meanwhile, the two systems for international operation and performance evaluation index have been put forward. The performance of international operation can be classified as financial performance or corporate value so that the operation effect of those China's enterprises going abroad can be better evaluated.