• Progress in Medical Physics
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• v.17 no.2
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• pp.77-82
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• 2006

The image display is an Important component of PACS and of medical digital imaging chain. Displayed image qualify is affected by the physical characteristics of display device, appropriate clinical settings and calibrations, and ambient lighting conditions. The performance of display systems is continuously degraded over time due to luminance deterioration and changes of clinical setting parameters. A routine QC is recommended because the performance of display systems is continuously degraded over time. Ten flat panel monochrome LCD display devices were included in the evaluation of the QC effect. The effect of QC on primary class LCD medical display devices for selected QC tests was evaluated by comparing the performances, luminance response, luminance dependencies, display resolution and display chromaticity in this study, of before and after the calibration procedures. The effects of the QC are significant to luminance response and luminance spatial dependencies test and the other side, are slight to the display resolution and display chromaticity test. A routine QC of display device is essential for the consistency of medical image display and presentation. The study of the QC effects of display devices will play an important role in practical QC procedures of display devices.

• Journal of Korean Home Economics Education Association
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• v.33 no.4
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• pp.31-48
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• 2021

The purpose of this study was to provide an understanding of the trajectories of multidimensional health among older adults, including depression, chronic diseases, and cognitive function. Data were drawn from the 1-6 waves of the Korean Longitudinal Study of Ageing(KLoSA), and a sample of 2,059 respondents aged 65 and older at baseline was used for the analyses. Latent growth curve models and growth mixture models were used to explore the changes in depression, chronic diseases, cognitive function, and heterogeneous trajectories among them. One-way ANOVAs with Scheffé post-hoc analysis and chi-square tests were used to find differences in sociodemographic characteristics, health behaviors, and life satisfaction across the latent trajectory classes. Latent growth curve models revealed that depressive symptoms and the number of chronic diseases increased over time, while cognitive function showed gradual decreases. Three heterogeneous patterns of multidimensional health trajectories were identified: normal aging, increase in chronic diseases, and chronic deterioration. Significant differences were observed in sociodemographic characteristics, health behaviors, and life satisfaction across the three latent classes. In particular, low educational attainment, household income, and life satisfaction were associated with the chronic deterioration class. Based on the findings, we discussed suggestions for health promotion education targeting older adults. This study also emphasizes the importance of home economics education in promoting health literacy across the life course.

• Journal of Chest Surgery
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• v.29 no.9
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• pp.971-976
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• 1996

From March 1988 to October 1992, 201 CarboMedics cardiac valve prostheses (150 mitral, 50 aortic and 1 tricuspid) were implanted in 166 consecutive patients (mean age 38 years, male/female 66/100) by one surgical team operating on adult cardiac patients at Kyungpook University Hospital. Total follow up represen:toed 6646 patient-months (mean 40mon1hs) and follow up rate was 96%. One hundred and twenty-four patients (74.7 %) were in NYHA functional class 111 or tV preoperatively and 164 patients (98.7 %) were in class I or ll postoperatively. Hospital mortality was 4.2 % and late death was 4.2%. The actuarial survival at 78 months was 89.4%. The linearized incidence of valve related death, prosthetic valve thrombosis, anticoagulant related hemorrhage, non-structural dysfunction and reoperation was 0.72%/pt-yr, 0.18%/pt-yr, 0.18%trapt-yr, 0.18 %/pt-yr and 0. 36%/pt-yr respective y. The 78 month rates of freedom from valve related death, prosthetic valve thrombosis, anticoagulant related hemorrhage, non-structural dysfunction and reoperation were 94.9%, 99.4%, 99.4%, 98.6 % and 97.9 % respectivly. The 78 month rate of freedom from all valve related complications and deaths including hospital mortality was 90.9%. These fact suggest that the CarboMedics cardiac valve has execellent result, low incidence of valve-ie-lated complications and no structural deterioration, and long term follow up study is necessary.

• 보존과학연구
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• s.22
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• pp.41-52
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• 2001

The wooden building is mainly damaged by the termite which have an effect of the structure by making emptied inner part of wood. One class, Japanese termite, inhabits throughout Korea and is often detected. So the deterioration by termite attacking the wooden building needs to be controlled. Termites are over 2,800 species in the world, usually they inhabit in the tropical or subtropical region and don’t over winter in dormant condition. So their activity and distribution are chiefly restricted by temperature and humidity. The termite inhabiting in Korea is Reticulitermes speratus kyushuensis Morimoto, which known to have an optimal temperature range at $12~30^{\circ}C$ and minimum temperature at $6^{\circ}C$ for activation. These temperatures correspond to the mean temperature($5.6^{\circ}C$~$25.8^{\circ}C$) from March to November and the activity time of termitein Seoul. In addition, as a result of environmental pollution by industrial development, the climate of Korea is getting warm. The increase of mean temperature in Korea has been $1.1^{\circ}C$ for the past seventy five years, so it is expected that the damage of wooden building by termite will increase gradually. Therefore, in order to protect wooden building from damages by termite, it needs not only development of new pest control methods, but also studies on the control of environmental factors having an effect on the activity and growth of termite. For the conservation of the large cultural properties such as the wooden building in the open air, it would be effective to use the methods of fumigation, insecticidal and antiseptic chemical treatment of wood materials, soil termiticideinjection treatment, and termite colony elimination system.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.92-94
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• 2003

The autotransformer currently used on the electric railway system is made of class A insulation material and uses the paper insulation method. As a power converter supplying power to the trolley wire, the autotransformer is one of critical equipment in the railway system. In the autotransformer, load irregularly changes and overload often occurs. These cause overheating of the autotransformer and facilitate deterioration of the autotransformer resulting in burnout accidents due to insulation breakdown. Also, the current autotransformer has poor insolation and short-circuit strength which often badly affect the service life of the transformer, and needs to improve its quality urgently. To overcome one of existing shortcomings of the mold transformer, manufacturers use epoxy resins that have superior flame retardancy to get rid of fro and explosion possibilities during accidents. Currently, new mold transformers are used in indoor distribution facilities with fire-fighting equipments. Coils molded in epoxy resins do not have their insulation performance compromised by humidity, dust, etc enabling easy inspection and maintenance. Comparing to the oil immersed transformer, the mold transformer does not have any concern about environmental pollutions by oil leak or replacement Therefore, to reduce breakdowns and improve reliability of the autotransformer, it is necessary to develop a new mold autotransformer with low loss suitable for our environment to suppress breakdowns of the autotransformer and improve the reliability. This study is about development of a low-loss mold autotransformer necessitated by reasons mentioned earlier.

• Transactions of the Korean hydrogen and new energy society
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• v.17 no.3
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• pp.293-300
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• 2006

KIER has been developing a Ru-based preferential oxidation catalysts and a novel fuel processing system to provide hydrogen rich gas to residential PEMFCs system. The catalytic activity of Ru-based catalysts was investigated at different Ru loading amount and different support structure. The obtained result indicated that 2 wt% loaded Ru-based catalyst supported on ${\alpha}-Al_2O_3$ showed high activity in low temperature range and suppressed the methanation reaction. The developed prototype fuel processor showed thermal efficiency of 78% as a HHV basis with methane conversion of 92%. CO concentration below 10 ppm in the produced gas is achieved with separate preferential oxidation unit under the condition of $[O_2]/[CO]=2.0$. The partial load operation have been carried out to test the performance of fuel processor from 40% to 80% load, showing stable methane conversion and CO concentration below 10 ppm. The durability test for the daily start-stop and 8 h operation procedure is under investigation and shows no deterioration of its performance after 50 start-stop cycles. In addition to the system design and development.

• Korean Journal of Environment and Ecology
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• v.5 no.1
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• pp.91-103
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• 1991

Use impacts on environmental deteriorations of trail and campsite were studied in Chirisan National Park in 1991. The entire width, bare width and maximum depth of trail as the trail condition were significantly greater on the more heavily used trail. Trail conditions, especially altitude, entire width and maximum depth of deteriorated points which were surveyed at the total of 82 were significantly different from those of non-deteriorated points. On the ridge trail, the damaged are more severe than Class 4 reaches about 34,000$m^2$ and use impacts on campsite and deterioration were also accelerated. The dominant trees of the upper layer in trail edge vegetation are changed from Carpinus tschonoskii to Quercus serrata, Carpinus laxiflora and to Quercus mongolica, Carpins laxiflora at Hwaeomsa trail, and from Quercus serrata to Quercus mongolica at Piagol trail. Also Lespedoza maximowiczii, Symplocos chinensis, Deutzia prunifolia, Weigela Subsessilis appear as the dominant lower species at Hwaeomsa trail, L. maximowiczii, S. chinensis, Stephanandra incisa, Rhododendron schlippenbachii for Piagol trail.

• Journal of the Earthquake Engineering Society of Korea
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• v.5 no.6
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• pp.37-46
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• 2001

In this research, a controller design method based on optimization is proposed that can satisfy constraints on maximum responses of building structures subject to around excitation modeled by partially stochastic process. The class of controllers to be optimized is restricted to LQR. Weighting matrix on controlled outputs is used as design variable. Objective function, constraint functions and their gradients are computed by the parameterization of control gain with Riccati matrix. Full state feedback controllers designed by proposed optimization method satisfy various design objectives and their necessary maximum control forces are computed for the production of actuator. LQG controllers composed of Kalman filter and LQR designed by proposed method perform well with little deterioration. So it is possible to design output feedback controllers satisfying constraints on various maximum responses of structures.

• Journal of Chest Surgery
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• v.27 no.12
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• pp.989-994
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• 1994

Between January 1986 and August 1993, 11 patients underwent surgical repair of ventricular septal defect [VSD] complicated with myocardial infarction. The ages of patients were ranged from 22 years to 83 years with a mean of 64 years. There were 8 male and 3 female patients. The preoperative cineangiograms of all patients were reviewed to measure both ventricular function and to evaluate coronary artery disease. The mean time interval between occurance of VSD and operation was 13 days. The operations were performed as soon as possible if there were hemodynamic derangement. Postmyocardial infarction VSD were repaired simultaneuously with coronary artery bypass graft in 3 patients, repaired with left ventricular aneurysmectomy in 6 patients, with left ventricular thrombectomy in 1 patient and with mitral valve chordae repair in 1 patient. There was no early death [within 30 days]. There were 6 postoperative complications; one with perioperative myocardial infarction, two with recurred VSD on postoperative 1 and 6 days respectively, two with lower leg embolism associated with intraaortic balloon pump insertion, one with wound infection. Of the complicated patients, 1 patient with lower leg embolism performed left above ankle amputation. Among two patients with recurred ventricular septal defect, one patient is doing well without problem. On follow up echocardiogram, the residual VSD was occluded completely. However another patient was with recurred VSD died 3 months after the operation because of congestive heart failure. Of the long term survivors, all patients are in NEW YORK Heart Association functional Class I or II. Although number of patients were small, our results of surgical closure of postmyocardial infarction VSD were favored to the others. Moreover, seven patients with preoperative cardiogenic shock among 11 were performed early operation after diagnosis of ventricular septal rupture. All of the patients were survived and doing well during the follow up period. Therefore early diagnosis with aggressive preoperative care with intraaortic balloon pumping and early operation seems to be very important for prevention of deterioration of vital organ.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.2
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• pp.55-62
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• 2005

There are many risk factors of electrical shock caused by a minimum of protective devices, loose working environments, deterioration of installations at temporary power installations of construction sites. An insulation cover for instrument transformer(MOF) used in 22.9[kV] class power receiving system hasn't shown good performance in terms of electrical safety because of short clearance between insulation cover and each input and output wire junction part. The insulation cover is easily moved by outside environment as wind or rain because of different size between insulation cover and busing, also can be leaded to breakdown by tracking. Therefore, we have proposed the insulation cover which effectively can prevent from electrical disaster in this paper, and a utility model patent had been registered already. To decrease the electric field concentrated on specific part, we had roundly designed the shape of insulation cover and the clearance between cover and live part was adjusted to be longer than the existing thing. The proposed insulation cover was evaluated by using the electric field solution program.