• Journal of Preventive Medicine and Public Health
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• v.30 no.1 s.56
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• pp.195-207
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• 1997

High price equipment is one of the major factors that increases national health expenditure in developed countries. Computerized Tomography(CT), one of the important high price equipment, has been concerns of health service researchers and policy makers in many countries. In Korea, CT, first introduced in 1984, have spreaded nationwide with rapid speed. Though the Committee for Approving Import of High Price Medical Equipment, founded in 1981, tried to regulate the introduction of high price medical equipment including CT, the effort resulted in failure. The exact situation of diffusion of the high price equipment, however, was not yet investigated. We aimed at the description of the diffusion of CT in Korea and analysis of influencing factors on hospitals for the adoption of CT. We mainly used the database of CT, made in 1996 by the National Federation of Medical Insurance for the purpose of insurance payment for CT. Also characteristics of hospitals were gathered from yearbooks published by the central and local governments and by the Korean Hospital Association. We calculated the cumulative number of the CT per one million population year by year. In turn, multiple linear logistic regression was done to find out the contributing factors for the adoption of CT by each hospital. In the logistic regression model, it is regarded as dependent factor whether a hospital retained CT or not in 1988 and 1993. The major categories of the independent factors were hospital characteristics, environmental factors and competitive conditions of hospitals at the period of the adoption. The results are as follows: Number of CT scanners per one million persons in Korea marked more higher level compared with those of most OECD countries. Major influencing factors on the adoption of CT scanners were hospital characteristics, such as hospital referral level, and competitive condition of hospitals, such as number of CT scanners per 10,000 persons in each district where the hospital was located. In Korea, CT diffused with rather rapid speed, comparable with those of the United States and Japan. The major factors contributing on the adoption of CT for hospitals were competitive condition and hospital characteristics rather than regional health care need for CT. In conclusion, a kind of regulating mechanism would be necessary for the prevention of the indiscreet adoption and inefficient use of high price equipment including CT.

• Journal of Korean Society of Steel Construction
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• v.17 no.2 s.75
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• pp.227-241
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• 2005

This paper presents a practical and realistic Life-Cycle Cost (LCC) optimum design methodology for steel bridges considering the long-term effect of environmental stressors such as corrosion and heavy truck traffics on bridge reliability. The LCC functions considered in the LCC optimization consist of initial cost, expected life-cycle maintenance cost, and expected life-cycle rehabilitation costs including repair/replacement costs, loss of contents or fatality and injury losses, road user costs, and indirect socio-economic losses. For the assessment of the life-cycle rehabilitation costs, the annual probability of failure, which depends upon the prior and updated load and resistance histories, should be accounted for. For the purpose, Nowak live load model and a modified corrosion propagation model, which takes into consideration corrosion initiation, corrosion rate, and repainting effect, are adopted in this study. The proposed methodology is applied to the LCC optimum design problem of an actual steel box girder bridge with 3 continuous spans (40m+50m+40m=130m). Various sensitivity analyses are performed to investigate the effects of various design parameters and conditions on the LCC-effectiveness. From the numerical investigation, it has been observed that local corrosion environments and the volume of truck traffic significantly influence the LCC-effective optimum design of steel bridges. Thus, these conditions should be considered as crucial parameters for the optimum LCC-effective design.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.1
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• pp.105-109
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• 2010

While numerous information services are provided on the Web as a core infrastructure of information society, semantic services using the Semantic Web technologies still stay deployed number and application range. This situation would be mainly originated from the failure of securing reliability to the user. Thus, this paper introduces an evaluation method for measuring reliabilities of the semantic services comparatively. To measure the reliability of the compared systems, the observer assesses 'precision in task performance' as a quantitative analysis and 'reliability of expectation-result' as a qualitative analysis described by the test persons. On the other hand, the test person should rate the functional reliability and reliability of the served information on the vector graph by himself with a scale from 0 to 5. Experimental results show that assessment by the observer is very similar to rating value by test persons, and that the accuracy of the served information has a close effect on the functional reliability. Through this paper, we can verify the essential factors for evaluating the reliability of semantic service systems. These are functional reliability and reliability of served information resulting from function execution. In particular, it has been proven that the reliability of the semantic information services largely influences the "Quality in Use" and therefore determines the major factors of the semantic service reliability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.542-550
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• 2020

A stream serve the functions of different water utilization, flood control, and the environment, and contributes to the development of national life and culture. On the other hand, it is difficult to efficiently evaluate various projects, such as effectiveness verification and comparison between projects, because the evaluation procedures and evaluation techniques of projects are not uniform and different for each institution. Therefore, a standardization technology was developed for a post-assessment of stream projects that can recognize stream problems and comprehensively evaluate stream-related projects. To this end, various projects, such as project evaluation techniques, national R&D projects, and social welfare projects, were compared and analyzed, and the standardization stages of the project were first suggested. In addition, based on the standardization stage, the evaluation indices for each stage were derived to develop an evaluation table that can evaluate stream-related projects comprehensively. Finally, it is possible to prevent the repeated use of failure factors in the planned projects.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.469-475
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• 2010

The railway signalling system plays an essential role in the safe and efficient train operation as serving control functions of train operation intervals and train routes. The reliability and safety of the system are very important because the failure of the railway signalling system can lead to train collision or derailment as well as train operation stop. Until now, in railway signalling system the conventional wayside signal mode has been used generally. There are, however, the risk of accidents such as human mistakes caused by that the driver identifies the signal lamp status and controls train speed with the naked eye. It is also necessary to refurbish the obsolete system. Thereby, It is being effective that the onboard signal mode has been recently introduced and applied in order to transmit the speed control information to train by using the computer and communication equipment. It is necessary to switch over the system in a way while providing passengers with an operation service to replace the obsolete signal system. In this paper, we verify the cases through trial assessment which are solved by the way of adding specific functionalities in the problems of interference among the procedure of switch-over processes and a serial of processes for system verification while a train is operated in the new system in parallel to the existing system.

• Journal of Korean Neurosurgical Society
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• v.63 no.5
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• pp.649-656
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• 2020

Objective : Unclear mental state is one of the major factors contributing to diagnostic failure of occult skeletal trauma in patients with traumatic brain injury (TBI). The aim of this study was to evaluate the overlooked co-occurring skeletal trauma through whole body bone scan (WBBS) in TBI. Methods : A retrospective study of 547 TBI patients admitted between 2015 and 2017 was performed to investigate their cooccurring skeletal injuries detected by WBBS. The patients were divided into three groups based on the timing of suspecting skeletal trauma confirmed : 1) before WBBS (pre-WBBS); 2) after the routine WBBS (post-WBBS) with good mental state and no initial musculoskeletal complaints; and 3) after the routine WBBS with poor mental state (poor MS). The skeletal trauma detected by WBBS was classified into six skeletal categories : spine, upper and lower extremities, pelvis, chest wall, and clavicles. The skeletal injuries identified by WBBS were confirmed to be simple contusion or fractures by other imaging modalities such as X-ray or computed tomography (CT) scans. Of the six categorizations of skeletal trauma detected as hot uptake lesions in WBBS, the lesions of spine, upper and lower extremities were further statistically analyzed to calculate the incidence rates of actual fractures (AF) and actual surgery (AS) cases over the total number of hot uptake lesions in WBBS. Results : Of 547 patients with TBI, 112 patients (20.4 %) were presented with TBI alone. Four hundred and thirty-five patients with TBI had co-occurring skeletal injuries confirmed by WBBS. The incidences were as follows : chest wall (27.4%), spine (22.9%), lower extremities (20.2%), upper extremities (13.5%), pelvis (9.4%), and clavicles (6.3%). It is notable that relatively larger number of positive hot uptakes were observed in the groups of post-WBBS and poor MS. The percentage of post-WBBS group over the total hot uptake lesions in upper and lower extremities, and spines were 51.0%, 43.8%, and 41.7%, respectively, while their percentages of AS were 2.73%, 1.1%, and 0%, respectively. The percentages of poor MS group in the upper and lower extremities, and spines were 10.4%, 17.4%, and 7.8%, respectively, while their percentages of AS were 26.7%, 14.2%, and 11.1%, respectively. There was a statistical difference in the percentage of AS between the groups of post-WBBS and poor MS (p=0.000). Conclusion : WBBS is a potential diagnostic tool in understanding the skeletal conditions of patients with head injuries which may be undetected during the initial assessment.

• Journal of Korea Water Resources Association
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• v.41 no.4
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• pp.379-394
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• 2008

Recently, extreme precipitation events beyond design capacity of hydraulic system have been occurred and this is the causes of failure of hydraulic structure for flood prevention and of severe flood damage. Therefore it is very important to understand temporal and spatial characteristics of extreme precipitation events as well as expected changes in extreme precipitation events and distributional characteristics during design period under future climate change. In this paper, climate change scenarios were used to assess the impacts of future climate change on extreme precipitation. Furthermore, analysis of future extreme precipitation characteristics and I-D-F analysis were carried out. This study used SRES B2 greenhouse gas scenario and YONU CGCM to simulate climatic conditions from 2031 to 2050 and statistical downscaling method was applied to establish weather data from each of observation sites operated by the Korean Meteorological Administration. Then quantile mapping of bias correction methods was carried out by comparing the simulated data with observations for bias correction. In addition Modified Bartlett Lewis Rectangular Pulse(MBLRP) model (Onof and Wheater, 1993; Onof 2000) and adjust method were applied to transform daily precipitation time series data into hourly time series data. Finally, rainfall intensity, duration, and frequency were calculated to draw I-D-F curve. Although there are 66 observation sites in Korea, we consider here the results from only Seoul, Daegu, Jeonju, and Gwangju sites in this paper. From the results we found that the rainfall intensity will be increased and the bigger intensity will be occurred for longer rainfall duration when we compare the climate conditions of 2030s with present conditions.

• Journal of Korean Neurosurgical Society
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• v.50 no.4
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• pp.332-340
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• 2011

Objective : Pyogenic spondylitis often results in acute neurological deterioration requiring adequate surgical intervention and appropriate antibiotic treatment. The purpose of this study was to conduct an analysis of the clinical effect of continuous irrigation via laminotomy in a series of patients with pyogenic spondylitis in thoracic and lumbar spine. Methods : The authors conducted a retrospective investigation of 31 consecutive patients with pyogenic thoracic and lumbar spondylitis who underwent continuous irrigation through laminotomy from 2004 to 2008. The study included 22 men and 9 women, ranging in age from 38 to 78 years (mean 58.1 years). The average follow-up duration was 13.4 months (range, 8-34 months). We performed debridement and abscess removal after simple laminotomy, and then washed out epidural and disc space using a continuous irrigation system. Broad spectrum antibiotics were administered empirically and changed according to the subsequent culture result. Clinical outcomes were based on the low back outcome scale (LBOS), visual analogue scale (VAS) score, and Frankel grade at the last follow-up. Radiological assessment involved plain radiographs, including functional views. Results : Common predisposing factors included local injection for pain therapy, diabetes mellitus, chronic renal failure, and liver cirrhosis. Causative microorganisms were identified in 22 cases (70.9%) : Staphylococcus aureus and Streptococcus spp. were the main organisms. After surgery, LBOS, VAS score, and Frankel grade showed significant improvement in most patients. Spinal stability was maintained during the follow-up period, making secondary reconstructive surgery unnecessary for all patients, except one. Conclusion : Simple laminotomy with continuous irrigation by insertion of a catheter into intervertebral disc space or epidural space was minimally invasive and effective in the treatment of pyogenic spondylitis. This procedure could be a beneficial treatment option in patients with thoracolumbar spondylitis combined with minimal or moderate destructive change of vertebrae.

• Journal of The Korean Association For Science Education
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• v.24 no.3
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• pp.468-480
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• 2004

It has been criticized that there are discrepancy between 'general statements' of the curriculum and subject-matter curricula. The possible reasons for this are as follows: The developers of the general statements were educational curriculum specialists. These specialists were not good enough to develop general statements and guidelines of subject matter curricula reflecting the characteristics of science contents, to examine developed science curriculum, and to give feedback to science curriculum developers. Under the present curriculum developing system where curriculum is developed in ten months or less by the research team commissioned unpredictably and imminently, it might be difficult to develop valid and precise science curriculum reflecting the purport of the general statements and teachers' needs. The inadequacy of these curriculum development processes resulted in (1) inconsistent statement about the school year to be applied to differentiated curriculum, (2) abstract and ambiguous stating about the characteristics, teaching-learning and assessment guidelines of enrichment activities, and (3) failure to reduce science contents to a reasonable level. Therefore curriculum development centers should be designated in advance to do basic research at ordinary times, and organized into a cooperative system among them. Two years or more of developing time and wider participation of scientists are recommended to develop more valid and precise science curriculum. In addition, commentaries on science curriculum should be published before textbook writing begins.

• Composites Research
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• v.24 no.1
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• pp.24-30
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• 2011

Low-velocity impact can cause various damages which are mostly hidden inside the laminates or occur in the opposite side. Thus, these damages cannot be easily detected by visual inspection or conventional NDT systems. And if they occurred between the scheduled NDT periods, the possibilities of extensive damages or structural failure can be higher. Due to these reasons, the built-in NDT systems such as real-time impact monitoring system are required in the near future. In this paper, we studied the impact monitoring system consist of impact location detection and damage assessment techniques for composite flat and stiffened panel. In order to acquire the impact-induced acoustic signals, four multiplexed FBG sensors and high-speed FBG interrogator were used. And for development of the impact and damage occurrence detections, the neural networks and wavelet transforms were adopted. Finally, these algorithms were embodied using MATLAB and LabVIEW software for the user-friendly interface.