• Journal of Chest Surgery
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• v.14 no.1
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• pp.40-48
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• 1981

Total anomalous venous return defines a group of congenital heart disease which have in common the entire pulmonary venous drainage returning directly or indirectly to the right atrium instead of to the left atrium. Despite of recent advance in treatment, this severe malformation in its various anatomical forms has a high surgical mortality during early infancy. Because of the high mortality in the untreated infant and the surgical risk in the first year of life, the timing of the operation remains important for optimal result. Three cases of T APV R, two supracardiac types and one mixed type, were treated with extracorporeal circulation during last three years in the Dept. of Thoracic and Cardiovascular Surgery, Seoul National University Hospital. The first one was 10 months old male with supracardiac type which drained through left innominate vein, and he was operated with profound hypothermia and total circulatory arrest but failed. The second case was 7 years old male with supracardiac type drained through left innominate vein, and he was well post operatively, and followed periodically for 12 months. The third case was 24 years old female with mixed type drainage (left upper pulmonary vein drained through left innominate vein, and the others through coronary sinus) was successfully corrected, and she was followed for 4 month without problem. All cases were diagnosed with cardiac catheterization and angiocardiogram, and also with echocardiogram in last two cases. In first two cases of supracardiac type, total circulatory arrest was used in brief period during anastomosis between common pulmonary venous trunk and left atrium. In the last case of mixed type, usual cardiopulmonary bypass with moderate hypothermia was used and total circulatory arrest was not needed.

• Archives of Plastic Surgery
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• v.43 no.3
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• pp.242-247
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• 2016

Background Median cleft lip is a rare anomaly consisting of a midline vertical cleft through the upper lip. It can also involve the premaxillary bone, the nasal septum, and the central nervous system. In our current report, we present the clinical features of 6 patients with a median cleft lip and their surgical management according to the accompanying anomalies. Methods From December 2010 to January 2014, 6 patients with a median cleft lip were reviewed. Five of these cases underwent surgical correction; alveolar bone grafting was performed in a patient with a median alveolar cleft. The surgical technique included inverted-U excision of the upper lip and repair of the orbicularis oris muscle. The mean follow-up period was 20.4 months (range, 7.4-44.0 months). Results The study patients presented various anomalous features. Five patients received surgical correction, 4 with repair of the median cleft lip, and one with iliac bone grafting for median alveolar cleft. A patient with basal sphenoethmoidal meningocele was managed with transoral endoscopic surgery for repair of the meningocele. Successful surgical repair was achieved in all cases with no postoperative complications. Conclusions Relatively mild forms of median cleft lip can be corrected with inverted-U excision with good aesthetic outcomes. In addition, there is a broad spectrum of clinical features and various anomalies, such as nasal deformity, alveolar cleft, and short upper frenulum, which require close evaluation. The timing of the operation should be decided considering the presence of other anomalies that can threaten patient survival.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.6
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• pp.290-297
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• 2014

The synchronization of OFDM receiver is consisted of symbol timing offset(STO) estimation in time domain and carrier frequency offset(CFO) estimation in frequency domain. This paper proposes new algorithm for correcting the integer CFO after we have done correcting the STO and partial CFO. ICFO must be corrected, since the ICFO lead to degrade bit error rate(BER) of demodulation performance. The PN sequence has information which is subcarrier order since the modified PN sequence, length is same subcarrier, is used in this paper and is modulated each subcarrier by each chip. Thus the receiver track phase of PN sequence after FFTin order to find the subcarrier frequency offset. The proposed algorithm is faster and more simple than convenient methode as measuring carrier energy.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.3
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• pp.322-330
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• 2014

New effective techniques to repair "small" design errors in integrated circuits are presented. As semiconductor chip complexity increases and the design period becomes tight, errors frequently remain in a fabricated chip making revisions required. Full mask revision significantly increases the cost and time-to-market. However, since many "small" errors can be repaired by modifying several connections among the circuit blocks and spare cells, errors can frequently be repaired by revising metal layers. Metal only revision takes significantly less time and involves less cost when compared to full mask revision, since mask revision costs multi-million dollars while metal revision costs tens of thousand dollars. In our research, new techniques are developed to further reduce the number of metal layers to be revised. Specifically, we partition the circuit blocks with higher error probabilities and extend the terminals of the signals crossing the partition boundaries to the preselected metal repair layers. Our partitioning and pin extension to repair layers can significantly improve the repairability by revising only the metal repair layers. Since pin extension may increase delay slightly, this method can be used for non-timing-critical parts of circuits. Experimental results by using academia and industrial circuits show that the revision of the two metal layers can repair many "small" errors at low-cost and with short revision time. On the average, when 11.64% of the spare cell area and 24.72% of the extended pins are added to the original circuits, 83.74% of the single errors (and 72.22% of the double errors) can be corrected by using two metal revision. We also suggest methods to use our repair techniques with normal commercial vender tools.

• International Journal of Aeronautical and Space Sciences
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• v.6 no.1
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• pp.44-51
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• 2005

To provide more accurate and reliable positioning and timing services to Korean nationwide users, the Ministry of Maritime Affairs and Fisheries of Korea is implementing Korean NDGPS (Nationwide DGPS), which is operational partly. And it also has a plan to construct WADGPS (Wide Area Differential GPS) system using sites and equipments of the NDGPS reference stations. For that, Seoul National University GNSS Laboratory is implementing and testing prototypes of WRS (Wide-area Reference Station) and WMS (Wide-area Master Station). Until now, because there are not enough installed WRSs to be used for computing wide area correction information, we cannot test algorithms of WMS with the data processed actually in WRSs. Therefore to evaluate the performance of the algorithms, we made a MATLAB program which can process RINEX (Receiver INdependent Exchange) format data with WADGPS algorithm. Using that program which consists of WRS, WMS and USER modules, we processed the data collected at NDGPS reference stations, which are saved in RINEX format. In WRS module, we eliminate the atmospheric delay error from the pseudorange measurement, smooth the measurement by hatch filter and calculate pseudorange corrections for each satellite. WMS module collects the processed data from each reference stations to generate the wide area correction information including estimated satellite ephemeris errors, ionospheric delays at each grid point, UDRE (User Differential Range Error), GIVE (Grid Ionosphere Vertical Error) and so on. In USER part, we use the measurements of reference stations as those of users and estimate the corrected users' positions and protection levels (HPL, VPL). With the results of estimation, we analyzed the performance of the algorithms. We assured the estimated UDRE /GIVE values and the protection levels bound the corresponding errors effectively. In this research, we can expect the possible performance of WADGPS in Korea, and the developed modules will be useful to implementation and improvement of the algorithms.

• The Journal of the Korean bone and joint tumor society
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• v.4 no.1
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• pp.22-29
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• 1998

A limb-sparing operation has a definitive role in the treatment of osteosarcoma in the lower extremity of skeletally-immature patients. After a limb-sparing operation, leg length discrepancy remains as a major disability that should be corrected. This study was designed to suggest methods of tumor resection and proper timing of leg length equalization in skeletally immature osteosarcoma patients. From September 1990 to January 1998, we reviewed eight osteosarcoma patients in an immature skeletal age. There were 4 males and 4 females, and their mean duration of follow-up was 50.37 months (range : 25 to 88 months). Mean skeletal age was 8 years (range : 8 months to 11 years). The patients were classified according to the methods of tumor resection ; intercalary resection in 1 case, transepiphyseal resection in 1, intra-articular resection in 5, and extra-articular resection in 1. The results were as follows ; 1. The leg lengthening was begun when a patient's leg length discrepancy reached 4-5cm. 2. The age of final lengthening with permanent reconstruction was 14 years in males and 12 years in females (about 2 years before skeletal maturity). 3. When reconstruction was performed with a temporary spacer, the site of lengthening Was in the soft tissue, not in bone, and then a permanant reconstruction was done. 4. Reconstruction with a biologic spacer to preserve the joint function was a reasonable method for equalization of leg length. In conclusion, the appropriate choice of reconstructive method and the age at which to correct the leg length discrepancy in a skeletally-immature osteosarcoma patients are important factors for maintaining leg length at full maturity.

• KDI Journal of Economic Policy
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• v.34 no.3
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• pp.1-29
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• 2012

Based on the spatial and land price data of innovation cities and their periphery areas in Korea, this study examines the degree and timing of changes in land price in relation to projects concerning innovation city. The study result confirms that the current system is inconsistent with the principle of restitution of development gain and therefore, this study attempts to seek improvement measures so that the current system can better fit the principle. The analysis reveals that most innovation cities, excluding Sinseo-dong of Daegu and Ujeong-dong of Ulsan, recorded a statistically significant increase in land prices since 2005, compared to those of their neighboring areas. It can be said that the information related to projects concerning innovation city was reflected in the land price since 2005. However, the standard land price pursuant to Article 70 of the Land Compensation Act is the officially assessed land price released on 1st of January 2007, and this official land price was actually applied to the compensation process. Therefore, estimating the compensation amount for land expropriation based on this land price will contradict the principle of restitution of development gain. In other words, despite the fact that development-related information was already reflected in land prices of innovation cities from 2005 to the end of 2006, the compensation process were carried out without institutional arrangements or efforts to exclude such reflection. To solve this problem, this study makes two suggestions. First, it is necessary to cast aside the limitations of the official land price that can be retroactively applied in accordance with Paragraph 5 of Article 70 of the Land Compensation Act, and instead apply the land price which is the most latest but deemed to have no reflection of development gains. Based on this revised standard land price, if the compensation amount is corrected by the average inflation rate and the average rate of increase in land price during the period until the time of the recognized land price, the amount would better satisfy the principle of restitution of development gain. Second, it is necessary to clearly stipulate the standards of development gains being reflected on the land price by including it in the secondary legislation. Under the current system, it is highly likely that appraiser's arbitrary interpretation on development gains is included in the process of calculating the amount of compensation for land expropriation. In this regard, it is necessary to improve the standards on determining whether development gains are reflected based on the results of this academic research and the existing guidelines for appraisal of compensation for land expropriation published by the Korea Association of Property Appraisers.

• The Journal of Engineering Geology
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• v.32 no.1
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• pp.113-126
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• 2022

The tectonic history of the Chukchi Abyssal Plain in the Amerasia Basin, Arctic Ocean, has not been fully explored due to the harsh conditions of sea ice preventing detailed observation. Existing models of the tectonic history of the region provide contrasting interpretation of the timing of formation of the crust (Mesozoic to Cenozoic), crust type (from hyper-extended continental crust to oceanic crust), and formation process (from parallel/fan-shaped rifting to transformation faulting). To help determine the age of the oceanic crust, the geothermal gradient was measured at three stations in the south of abyssal plain at depth of 2,160-2,250 m below sea level. Heat flow measurement stations were located perpendicular to the spreading axis over a 40 km-long transect. In-situ thermal conductivity measurement, corrected by the laboratory test, gave observed marine heat flows of 55 to 61 mW/m². All measurements were taken during Arctic expeditions in 2018 (ARA09C expedition) and 2021 (ARA12C expedition) by the Korean ice-breaking research vessel (IBRV) Araon. Given the assumption of oceanic crust, the results correspond to formation in the Late Cretaceous (Mesozoic). The inferred age supports the hypothesis of formation activated by the opening of the Makarov Basin during the Late Mesozoic-Cenozoic. This would make it contemporaneous with rifting of the Chukchi Border Land immediately east of the abyssal plain. The heat flow data indicate the base of the gas hydrate stability zone is located 332-367 m below the seafloor, this will help to identify the gas hydrate-related bottom simulating reflector in the future seismic survey, as already identified on the Chukchi Plateau. Further geophysical surveys, including heat flow measurements, are required to increase our understanding of the formation process and thermal mantle structure of the abyssal plain.

• Tuberculosis and Respiratory Diseases
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• v.42 no.3
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• pp.361-369
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• 1995

Background: A number of different weaning techniques can be employed such as spontaneous breathing trial, Intermittent mandatory ventilation(IMV) or Pressure support ventilation(PSV). However, the conclusive data indicating the superiority of one technique over another have not been published. Usually, a conventional spontaneous breathing trial is undertaken by supplying humidified $O_2$ through T-shaped adaptor connected to endotracheal tube or tracheostomy tube. In Korea, T-tube trial is not popular because the high-flow oxygen system is not always available. Also, the timing of extubation is not conclusive and depends on clinical experiences. It is known that to withdraw the endotracheal tube after weaning is far better than to go through any period. The tube produces varying degrees of resistance depending on its internal diameter and the flow rates encountered. The purpose of present study is to evaluate the effectiveness of weaning and extubation following a 60 minutes spontaneous breathing trial with simple oxygen supply through the endotracheal tube. Methods: We analyzed the result of weaning and extubation following a 60 minutes spontaneous breathing trial with simple oxygen supply through the endotracheal tube in 18 subjects from June, 1993 to June, 1994. They consisted of 9 males and 9 females. The duration of mechanical ventilation was from 38 hours to 341 hours(mean: $105.9{\pm}83.4$ hours). In all cases, the cause of ventilator dependency should be identified and precipitating factors should be corrected. The weaning trial was done when the patient became alert and arterial $O_2$ tension was adequate($PaO_2$ > 55mmHg) with an inspired oxygen fraction of 40%. We conducted a careful physical examination when the patient was breathing spontaneously through the endotracheal tube. Failure of weaning trial was signaled by cyanosis, sweating, paradoxical respiration, intercostal recession. Weaning failure was defined as the need for mechanical ventilation within 48 hours. Results: In 19 weaning trials of 18 patients, successful weaning and extubation was possible in 16/19(84.2 %). During the trial of spontaneous breathing for 60 minutes through the endotracheal tube, the patients who could wean developed slight increase in respiratory rates but significant changes of arterial blood gas values were not noted. But, the patients who failed weaning trial showed the marked increase in respiratory rates without significant changes of arterial blood gas values. Conclusion: The result of present study indicates that weaning from mechanical ventilation following a 60 minutes spontaneous breathing with $O_2$ supply through the endotracheal tube is a simple and effective method. Extubation can be done at the same time of successful weaning except for endobronchial toilet or airway protection.