• Journal of Chest Surgery
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• v.29 no.1
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• pp.32-37
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• 1996

Between May 1991 and September 1995, 7 patients underwent surgical repair of ventricular septal defect (VSD) complicated with myocardial infarction in Asan Medical Center. The patients included two male and five female. The ages of patients were ranged from 54 years to 76 years with a mean of 65 years. The sites of postinfarction ventricular septal defect were consist of anterior septal defect in 6 patients and anteroposterior septal defect in 1 patient. Preoperative 2D-echocardiography & angiography were performed in all patients in order to measure ventricular function and evaluate the extent of coronary artery disease. The operations were delayed till mean 24 $\pm$ 12days after myocardial infarction. All patients underwent infarctectomy and Teflon patch closures through the area of the left ventricle infarction or aneurysm in the anterior or apical aspect of postinfarction ventricular septal defect. The ventricular septal defect repaired simultaneously with coronary artery b pass graft in 3 patients, with ventricular aneurysmectomy in 5 patients, and with left ventricular thrombectomy in 1 patient. Patch fixation in the left side of interventricular septum by tracts-septal interrupted pledget suture reduced the recurrence rate of VSD. There were 2 postoperative complications : One with pneumonia, 1 patient with the skin necrosis of left thigh. There was ilo early death. The 6 patients except for one emigrant were followed up postoperatively between 3 and 63 months(mean .28 months), without any sequelae and late death. They are in New York Heart Association functional class I-II.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.10
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• pp.82-90
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• 2011

Because of the development of Smart phone devices, the demands of high performance FPU(Floating-point Unit) becomes increasing. Therefore, we propose the high-speed single-/double-precision FPU design that includes an elementary add/sub unit and improved multiplier and compare and convert units. The most commonly used add/sub unit is optimized by the parallel rounding unit. The matrix operation is used in complex calculation something like a graphic calculation. We designed the Multiply-Add Fused(MAF) instead of multiplier to calculate the matrix more quickly. The branch instruction that is decided by the compare operation is very frequently used in various programs. We bypassed the result of the compare operation before all the pipeline processes ended to decrease the total execution time. And we included additional convert operations that are added in IEEE754-2008 standard. To verify our RTL designs, we chose four hundred thousand test vectors by weighted random method and simulated each unit. The FPU that was synthesized by Samsung's 45-nm low-power process satisfied the 600-MHz operation frequency. And we confirm a reduction in area by comparing the improved FPU with the existing FPU.

• Journal of Agricultural Extension & Community Development
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• v.23 no.2
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• pp.195-210
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• 2016

The study Development of the Agricultural Cooperative in Cambodia seek to explore the progress of agricultural cooperative( AC) development in Cambodia and South Korea. The experiences of Korea AC development are used to improve the Cambodian ACs. The results of study gave a lessons that the Korea ACs, which were multipurpose cooperatives were formed and owned by the government and had been considered as a successful development strategy for rural and agricultural development. As the government directly managed the businesses and other operations, available budgets, close with monitoring, and active member's participation the AC in Korea progressed rapidly for both the members and business scopes and it hugely contributed to rural development of Korea. For the future development of AC in Cambodia recommendations based on lessons from Korea AC will give a message to government and NGO. Rural Development always related with farmer's life. To live well in rural area provide effective mechanism to income increase. To development of AC in Cambodia is future of rural development.

• Journal of the Korea Society of Computer and Information
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• v.26 no.11
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• pp.1-9
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• 2021

3D-NAND flash memory provides high capacity per unit area by stacking 2D-NAND cells having a planar structure. However, due to the nature of the lamination process, there is a problem that the frequency of error occurrence may vary depending on each layer or physical cell location. This phenomenon becomes more pronounced as the number of write/erase(P/E) operations of the flash memory increases. Most flash-based storage devices such as SSDs use ECC for error correction. Since this method provides a fixed strength of data protection for all flash memory pages, it has limitations in 3D NAND flash memory, where the error rate varies depending on the physical location. Therefore, in this paper, pages and layers with different error rates are classified into clusters through the K-means machine learning algorithm, and differentiated data protection strength is applied to each cluster. We classify pages and layers based on the number of errors measured after endurance test, where the error rate varies significantly for each page and layer, and add parity data to stripes for areas vulnerable to errors to provides differentiate data protection strength. We show the possibility that this differentiated data protection policy can contribute to the improvement of reliability and lifespan of 3D NAND flash memory compared to the protection techniques using RAID-like or ECC alone.

• Atmosphere
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• v.31 no.2
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• pp.241-249
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• 2021

A smart city utilizes data collected from various sensors through the internet of things (IoT) and improves city operations across the urban area. Recently substantial research is underway to examine all aspects of data that requires for the smart city operation. Atmospheric data are an essential component for successful smart city implementation, including Urban Air Mobility (UAM), infrastructure planning, safety and convenience, and traffic management. Unfortunately, the current level of conventional atmospheric data does not meet the needs of the new city concept. New and innovative approaches to developing high spatiotemporal resolution of observational and modeling data, resolving the complex urban structure, are expected to support the future needs. The geographic information system (GIS) integrates the atmospheric data with the urban structure and offers information system enhancement. In this study we proposed the necessity and applicability of the high resolution urban meteorological dataset based on heavy fog cases in the smart city region (e.g., Sejong and Pusan) in Korea.

• Informatization Policy
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• v.30 no.1
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• pp.41-66
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• 2023

This study aims to reveal the direction of municipal ordinances for smart cities, while focusing on 74 municipal ordinances from 72 municipal governments through topic modeling. As a result, the main keywords that show a high frequency belong to establishment and operations of the Smart City Committee. From the result of topic modeling Latent Dirichlet Allocation(LDA), it classifies municipal ordinances for smart cities into eight topics as follows: Topic 1(security for process of smart cities), Topic 2(promotion of smart city industry), Topic 3(composition of a smart city consultative body for local residents), Topic 4(support system for smart cities), Topic 5(management for personal information), Topic 6(use of smart city data), Topic 7(implementation for intelligent public administration), and Topic 8(smart city promotion). As for topic categorization by region, Topics 5, 6, and 8 which are mostly related to the practical operation of smart cities have a significant portion of municipal ordinances for smart cities in the Seoul metropolitan area. Then, Topics 2, 3, and 4 which are mostly related to the initial implementation of smart cities have a significant portion of municipal ordinances for smart cities in provincial areas.

• The Journal of Society for e-Business Studies
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• v.20 no.1
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• pp.183-199
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• 2015

Due to the Four Major Rivers Restoration Project, Nakdong River Estuary Barrage's designed flood quantity has been largely increased, and this has caused to construct several drainage gates at the right side of Eulsukdo island to secure the safety of downstream river area. For successful functioning of Nakdong River Estuary Barrage, such as flood control, disaster prevention, and the securing of sufficient water capacity, drainage gates at the both sides of island have to operate systematically and reliably. To manage this under restricted personnel and resources, we have implemented the IOS (Integrated Operation System) by integrating previous facilities and resources via information and communication technologies. The IOS has been designed to have higher availability and fault tolerance to function continuously even with the partial system's failure under the emergency situation like flood. Operators can use the system easily and acknowledge alarms of facilities through its IWS (Integrated Warning System) earlier. Preparing for Integrated Water Resources Management and Smart Water Grid, the architecture of IOS conformed to open system standards which will be helpful to link with the other systems easily.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.2
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• pp.26-32
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• 2008

Video compression schemes have been developed and used for many years. Currently, H.264/AVC is the most efficient video coding standard. The H.264/AVC baseline profile adopts CAVLC(Context-Adaptive Variable Length Coding) method as an entropy coding method. CAVLC gives better performance in compression ratios than conventional VLC(Variable Length Coding). However, because CAVLC decoder uses a lot of VLC tables, the CAVLC decoder requires a lot of area in terms of hardware. Conversely, since it must look up the VLC tables, it gives a worse performance in terms of software. In this paper, we propose a new hierarchical grouping method for the VLC tables. We can obtain an index of codes in the reconstructed VLC tables by simple arithmetic operations. In this method, the VLC tables are accessed just once in decoding a symbol. We modeled the proposed algorithm in C language, compiled under ARM ADS1.2 and simulated it with Armulator. Experimental results show that the proposed algorithm reduces execution time by about 80% and 15% compared with the H.264/AVC reference program JM(Joint Model) 10.2 and the arithmetic operation algorithm which is recently proposed, respectively.

• The Korean Journal of Applied Statistics
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• v.28 no.6
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• pp.1275-1288
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• 2015

A microscale weather analysis module (about 1km or less) is a microscale numerical weather prediction model designed for operational forecasting and atmospheric research needs such as radiant energy, thermal energy, and humidity. The accuracy of the module is directly related to the usefulness and quality of real-time microscale weather information service in the metropolitan area. This paper suggests an object based verification method useful for spatio-temporal evaluation of the accuracy of the microscale weather analysis module. The method is a graphical method comprised of three steps that constructs a lattice field of evaluation statistics, merges and identifies objects, and evaluates the accuracy of the module. We develop lattice fields using various evaluation spatio-temporal statistics as well as an efficient object identification algorithm that conducts convolution, masking, and merging operations to the lattice fields. A real data application demonstrates the utility of the verification method.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.24 no.2
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• pp.201-208
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• 2006

Currently, 1/5,000 Digital Topographic Map covers the whole country with administrative boundary of Gu, while some region has already been constructed with 1/1,000 digital topographic map has legal boundary of Dong. Here, Dong in 1/1,000 scale represents the legal boundary which is used in the address most of time. Therefore, there is no administrative-Dong yet although it is very useful in various fields. In this study, we suggested a method to construct the administrative boundary extending to the level of Dong empirically. In addition, the practical application of the administrative boundary in GIS is discussed. Two methods are applied to construct the administrative boundary to the level of administration-Dong; using the edited cadastral map and the digital topographic map. When the edited cadastral map is used, some problems such as boundary discordance to superordinate administrative area is appeared. On the other hand, using digital topographic map showed simple construction processes and easy connection with other framework data. Therefore, it is recommended that the digital topographic map should be used in the construction of the administrative boundary. It would be useful as framework data in various industries and public operations.