• Journal of Chest Surgery
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• v.51 no.3
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• pp.172-179
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• 2018

Background: This study aimed to compare preliminary data on the outcomes of sutureless aortic valve replacement (SU-AVR) with those of aortic valve replacement (AVR). Methods: We conducted a retrospective study of SU-AVR in moderate- to high-risk patients from 2013 to 2016. Matching was performed at a 1:1 ratio using the Society of Thoracic Surgeons predicted risk of mortality score with sex and age. The primary outcome was 30-day mortality. The secondary outcomes were operative outcomes and complications. Results: A total of 277 patients were studied. Ten patients (50% males; median age, 81.5 years) underwent SU-AVR. Postoperative echocardiography showed impressive outcomes in the SU-AVR group. The 30-day mortality was 10% in both groups. In our study, the patients in the SU-AVR group developed postoperative thrombocytopenia. Platelet counts decreased from $225{\times}10^3/{\mu}L$ preoperatively to 94.5, 54.5, and $50.1{\times}10^3/{\mu}L$ on postoperative days 1, 2, and 3, respectively, showing significant differences compared with the AVR group (p=0.04, p=0.16, and p=0.20, respectively). The median amount of platelet transfusion was higher in the AVR group (12.5 vs. 0 units, p=0.052). Conclusion: There was no difference in the 30-day mortality of moderate-to high-risk patients depending on whether they underwent SU-AVR or AVR. Although SU-AVR is associated with favorable cardiopulmonary bypass and cross-clamp times, it may be associated with postoperative thrombocytopenia.

• Journal of the Korean Society of Safety
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• v.35 no.1
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• pp.97-106
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• 2020

The objective of this paper is to suggest a new quantification method for multi-unit probabilistic safety assessment (PSA) that removes the overestimation error caused by the existing delete-term approximation (DTA) based quantification method. So far, for the actual plant PSA model quantification, a fault tree with negates have been solved by the DTA method. It is well known that the DTA method induces overestimated core damage frequency (CDF) of nuclear power plant (NPP). If a PSA fault tree has negates and non-rare events, the overestimation in CDF drastically increases. Since multi-unit seismic PSA model has plant level negates and many non-rare events in the fault tree, it should be very carefully quantified in order to avoid CDF overestimation. Multi-unit PSA fault tree has normal gates and negates that represent each NPP status. The NPP status means core damage or non-core damage state of individual NPPs. The non-core damage state of a NPP is modeled in the fault tree by using a negate (a NOT gate). Authors reviewed and compared (1) quantification methods that generate exact or approximate Boolean solutions from a fault tree, (2) DTA method generating approximate Boolean solution by solving negates in a fault tree, and (3) probability calculation methods from the Boolean solutions generated by exact quantification methods or DTA method. Based on the review and comparison, a new intersection removal by probability (IRBP) method is suggested in this study for the multi-unit PSA. If the IRBP method is adopted, multi-unit PSA fault tree can be quantified without the overestimation error that is caused by the direct application of DTA method. That is, the extremely overestimated CDF can be avoided and accurate CDF can be calculated by using the IRBP method. The accuracy of the IRBP method was validated by simple multi-unit PSA models. The necessity of the IRBP method was demonstrated by the actual plant multi-unit seismic PSA models.

• Biodesign
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• v.7 no.1
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• pp.24-27
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• 2019

Pnc1 converts nicotinamide to nicotinic acid to generate NAD⁺ through the Preiss-Handler pathway that is one of the NAD⁺-salvage pathway. By reducing levels of nicotinamide, an inhibitor of the NAD⁺-dependent histone deacetylase Sir2, yeast Pnc1 contributes gene silencing. In this study, to understand the structural features and molecular mechanism of nicotinamidase Pnc1, we overexpressed, purified, and crystallized the N-terminally His₆-tagged Pnc1 protein from Kluyveromyces lactis and obtained X-ray diffraction data at a resolution of 2.2 Å. The crystals of the K. lactis Pnc1 (KlPnc1) belonged to space group P2₁2₁2₁ with unit cell parameters a=38.5, b=77.3, c=83.3, and α=β=γ= 90°. There is one molecule in the asymmetric unit.

• Korean Journal of Plant Resources
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• v.9 no.3
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• pp.203-210
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• 1996

The activities of the antioxidative enzymes in the roots of Codonopsis lanceolata have been compared depending on the cultivated environments - wildness, cultivate paddy fields and cultivate dry fields - and the parts of the root. In the Codonopsis lanceolata raised in cultivate paddy fields, the activity of SOD was higher in 2 yrs old than 1 yr old, but the activity in 1 yr old was higher than in 2 yrs old for the plants raised in the cultivate dry fields. The specific activity of SOD in wildness plants 86.069unit/mg protein was the highest among plants studied. The tissue distribution of the SOD activity showed differences depending on the enviroment. The highest activity of SOD was shown in the upper part of the root for the cultivate paddy fields, the loewr parts for the cultivate dry fields and middle parts for the wildness. The specific activity of POD was increased with ages of the plants, and that in the wildness was the highest 68 unit/mg protein among the plants studied. The activity of POD in the parts of the roots was shown as middle>lower>upper. The activity of POD in the middle part of the root, rasied in Soebick province was 85 unit/mg protein. The specific activity of CAT was decreased with ages of the plants. The activities of wildness and cultivate paddy fields was similar, but that in cultivate dry fields was lower than others. The tissue distribution in the parts of the roots was upper>lower>middle. The activity of CAT middle part of rasied in the Sebuck area was 5.359 unit/mg protein. The activities antioxidative in the cells cultured in MSID(Murashige and Skoog +2.4-D 1mg/$\iota$) was followings: 1564 for CAT. 30 for POD and 22200 unit/mg protein for SOD. These figures were lower than that in in vivo.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.1
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• pp.107-120
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• 2019

The decommissioning of one nuclear power plant in a multi-unit nuclear power plant (multi-unit NPP) site may pose radiation exposure risk to decommissioning workers. Thus, it is essentially required to evaluate the exposure dose of decommissioning workers of operating multi-unit NPPs nearby. The ENDOS program is a dose evaluation code developed by the Korea Atomic Energy Research Institute (KAERI). As two sub-programs of ENDOS, ENDOS-ATM to anticipate atmospheric transport and ENDOS-G to calculate exposure dose by gaseous radioactive effluents are used in this study. As a result, the annual maximum individual dose for decommissioning workers is estimated to be $2.31{\times}10^{-3}mSv{\cdot}y^{-1}$, which is insignificant compared with the effective dose limit of $1mSv{\cdot}y^{-1}$ for the public. Although it is revealed that the exposure dose of operating multi-unit NPPs does not result in a significant impact on decommissioning workers, closer examination of the effect of additional exposure due to actual demolition work is required. The calculation method of this study is expected to be utilized in the future for planned decommissioning projects in Korea. Because domestic NPPs are located in multi-unit sites, similar situations may occur.

• Imaging Science in Dentistry
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• v.37 no.2
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• pp.65-68
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• 2007

Purpose: To compare the leakage and scattered radiation from hand-held dental X-ray unit with radiation from fixed dental X-ray unit. Materials and Methods: For evaluation we used one hand-held dental X-ray unit and Oramatic 558 (Trophy Radiologie, France), a fixed dental X-ray unit. Doses were measured with Unfors Multi-O-Meter 512L at the right and left hand levels of X-ray tube head part for the scattered and leakage radiation when human skull DXTTR III was exposed to both dental X-ray units. And for the leakage radiation only, doses were measured at the immediately right, left, superior and posterior side of the tube head part when air was exposed. Exposure parameters of handheld dental X-ray unit were 70 kVp, 3 mA, 0.1 second, and of fixed X-ray unit 70 kVp, 8 mA, 0.45 second. Results: The mean dose at the hand level when human skull DXTTR III was exposed with portable X-ray unit $6.39{\mu}Gy$, and the mean dose with fixed X-ray unit $3.03{\mu}Gy$ (p<0.001). The mean dose at the immediate side of the tube head part when air was exposed with portable X-ray unit was $2.97{\mu}Gy$ and with fixed X-ray unit the mean dose was $0.68{\mu}Gy$ (p<0.01). Conclusions: The leakage and scattered radiation from hand-held dental radiography was greater than from fixed dental radiography.

• Journal of Broadcast Engineering
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• v.17 no.2
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• pp.354-362
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• 2012

Recently, High Efficiency Video Coding (HEVC) is under development jointly by MPEG and ITU-T for the next international video coding standard. Compared to the previous standards, HEVC supports variety of splitting units, such as coding unit (CU), prediction unit (PU), and transform unit (TU). Among them, it has been known that the recursive quadtree structure of CU can improve the coding efficiency while the encoding complexity is increased significantly. In this paper, a simple conditional probability to predict the early termination condition of recursive unit structure is introduced. The proposed conditional probability is estimated based on Bayes' formula from local statistics of rate-distortion costs in encoder. Experimental results show that the proposed method can reduce the total encoding time by about 32% according to the test configuration while the coding efficiency loss is 0.4%-0.5%. In addition, the encoding time can be reduced by 50% with 0.9% coding efficiency loss when the proposed method was used jointly with HM4.0 early CU termination algorithm.

• Korean Institute of Interior Design Journal
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• v.16 no.4
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• pp.54-61
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• 2007

The purpose of this study was to investigate the spatial characteristics of residential and nursing units in large skilled nursing facilities for the elderly that were located in city areas, and to discuss the way for efficient unit care. For collecting the data, the researcher visited 6 facilities to make explorations and to interview the staff concerned. Most of the research facilities had systematic residential units that each unit basically had elderly private rooms and the spaces for small group. The number of elderly residents per unit was appropriate for the limit which was suggested by Kwon(2002), but the sizes of small group spaces were smaller than the standard limit($1.62m^{2}$ per resident). The nursing units were made up of nursing station, 2-4 residential units, spaces for large group of residents, hair dressing, nurse, living assistants, bathing, storage and etc. Some of them had problem in efficiency of space use because they did not have distinct usage. In conclusion, this study suggests that each floor has one nursing unit including 40 residents maximum and each nursing unit consists of 2-3 residential units that have 20 residents maximum per unit. In each residential unit, the furniture and spaces for efficient unit-care should be arranged, such as TV, dining table, kitchenette, bathroom, and rooms for living assistants. The hall type is better for the small group so that it has a transitional characteristic leading to the public spaces. The large group space needs to have clear usage such as conducting program differentiated from small group, and various furniture such as sofa, TV, table, and etc which encourage the elderly voluntary use.

• Journal of Industrial Technology
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• v.13
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• pp.89-96
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• 1993

In this paper, an OPS(Optical Protection Socket) unit is designed and prototyped for the application in the optical CPN(Customer Premises Network). The OPS unit, which plays an important role in the CPN for the enhanced network reliability, is consisted of $1{\times}2$ optical fiber splitter, combiner, and $1{\times}1$ optical switch to be a hybrid-typed unit. Various considerations, about power burget and optical information loss have given the most practical design for OPS. From the measurement of the realized OPS unit, it has proved such as the pertinent switching delay time with minimum data loss, the perceptive ability on the ONU degradation, the switching ability on the ONU malfunction.

• International Journal of Automotive Technology
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• v.4 no.2
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• pp.57-64
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• 2003

The Intelligent Power Unit (IPU) utilized in Honda's Civic Hybrid Integrated Motor Assist (IMA) system was developed with the aim of making every component lighter, more compact and more efficient than those in the former model. To reduce energy loss, inverter efficiency was increased by fine patterning of the Insulated Gate Bipolar Transistor (IGBT) chips, 12V DC-DC converter efficiency was increased by utilizing soft-switching, and the internal resistance of the IMA battery was lowered by modifying the electrodes and the current collecting structure. These improvements reduced the amount of heat generated by the unit components and made it possible to combine the previously separated Power Control Unit (PCU) and battery cooling systems into a single system. Consolidation of these two cooling circuits into one has reduced the volume of the newly developed IPU by 42% compared to the former model.