• Progress in Medical Physics
• /
• v.18 no.3
• /
• pp.144-148
• /
• 2007

Current digital radiography systems are rapidly glowing in clinical applications. The purpose of this study was to evaluate the characteristics of a mobile digital radiographic system. The performance of the mobile DR system was evaluated by measuring the modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE). Measurements were made on a LISTEM Mobix-1000 generator and a Teleoptic PRA Alpha-R4000 detector. Imaging characteristics were measured for these two systems using the IEC-61267 defined RQA5 (kVp: 74, additional filtration: 21 mmAl) radiographic condition. The MTF at 10% was measured as 2.4 cycles/mm and the DQE(0) values for radiation exposure 0.19, 0.5, and 1.3 mR were measured as 54%, 55%, and 76%, respectively. The NPS curves gradually decreased at high spatial frequencies. This high DQE at low frequencies, may be useful for low frequency information. The results suggested that mobile DR system could be integrated with emergency ambulance system in teleradiologic imaging applications.

• Research in Community and Public Health Nursing
• /
• v.14 no.2
• /
• pp.200-210
• /
• 2003

Purpose: This quasi-experimental study was performed to investigate the effects of a health promotion program(HPP) on self-efficacy, healthy lifestyle and blood lipid profile in employees with hyperlipidemia. Methods: The subjects were forty-three employees who were diagnosed as having hyperlipidemia during routine health examination at two worksites in Seoul in 2001. Of the forty-three subjects, thirty were allocated to the experimental group and the remaining thirteen were allocated to the control group. Data were collected from September 24, 2001 to March 16, 2002. The HPP was applied to the experimental group for 11 weeks and included health education, diet counseling, watching videos, conference, and so on. The health education included information about exercise, smoking cessation, and abstinence from drinking alcohol and seven sessions of hyperlipidemia education. The experimental group was requested to keep a daily health promotion lifestyle diary. This diary was analyzed by a dietician and subjects were instructed based on the results. As for data analyses, wilcoxon signed rank test and wilcoxon rank sum test and x2-test were carried out using SAS program. Results: 1. Self-efficacy scores of the experimental group were significantly more increased than those of the control group (experimental: 5.86 10.80, control: -4.04 11.91, p=0.018). 2. Healthy lifestyle scores of the experimental group were significantly more increased than those of the control group (experimental: 0.19 0.26, control: -0.05 0.29, p=0.024). 3. Blood total cholesterol values of the experimental group were significantly more decreased than those of the control group (experimental: -13.07 30.10mg/dl, control: 10.00 26.57mg/dl, p=0.033). 4. Blood triglyceride values of the experimental group were significantly more decreased than those of the control group (experimental: -29.17 192.40mg/dl, control: 63.31 107.53mg/dl, p=0.050). Conclusion: These findings indicate that the HHP could be effective in improving self-efficacy, healthy lifestyle and blood HDL cholesterol and decreasing blood total cholesterol in employees with hyperlipidemia. Therefore, the HHP could be suggested as an effective nursing intervention for employees in the worksite by ultimately preventing cerebral and cardiac vessel complications related to hyperlipidemia.

• Journal of Korean Neurosurgical Society
• /
• v.29 no.2
• /
• pp.167-179
• /
• 2000

Objective : We studied to clarify the effective time zone of mild hypothermic neural protection during ischemia and/or reperfusion after middle cerebral artery occlusion. Methods : In a reversible cerebral infarct model which maintained reperfusion of blood flow after middle cerebral artery occlusion for two hours, the size of cerebral infarction, cerebral edema and the extent of neurological deficit were observed and analyzed for comparison between the control and the experimental groups under hypothermia($33.5^{\circ}C$). The temporalis muscle temperature was reduced to $33.5^{\circ}C$ by surface cooling for two hours during middle cerebral artery occlusion for study group I. The following groups applied hypothermia for two-hour periods after reperfusion : group II(0-2 hours), group III(2-4 hours), and group IV(4-6 hours). They were rewarmed to $36.5^{\circ}C$ until sacrified at 2, 4, 6, 12, and 24 hours after reperfusion. Control group was maintained at normothermia without hypothermia. Results : In the experimental groups with hypothermia, the average value of the size of cerebral infarction($mean{\pm}SD$) was $1.97{\pm}1.65%$, which was a remarkable reduction over that of the control, $4.93{\pm}3.79%$. In the control, a progressive increase was shown in the size of infarction from point of reperfusion to 6 hours after reperfusion without further changes in size afterward. Intra-ischemic hypothermia(group I) prevented ischemic injury but did not prevent reperfusion injury. Group II examplified the most neural protective effect in comparison to the control group and group IV(p<0.05). The cortex was more vulnerable to reperfusion injury than the subcortex. Mild hypothermia showed more neural protective effects on the cortex than subcortex. Conclusion : The most appropriate time zone for application of mild hypothermia was defined to be within four hours following reperfusion.

• Progress in Medical Physics
• /
• v.14 no.3
• /
• pp.161-166
• /
• 2003

To evaluate the performance of cadmium sulfide as a multi-function X-ray dosimeter, we made an X-ray detector that was based on cadmium sulfide using evaporation technology, and measured its response to X-ray exposure. The voltages of cadmium sulfide were measured on the various X-ray tube potentials, X-ray tube currents and exposure times. The regression analysis of the voltage response of CdS on the tube-potential variation was y=0.0995x-0.1146 ($R^2$=0.9595, $\sigma$=0.08, standard error=2%) and the regression analysis of the voltage response of CdS on the tube-potential variation was y=0.0439x+1.1891 ($R^2$=0.9021, $\sigma$=0.04, standard error=1.8%) The regression analysis of the voltage response of CdS on the X-ray exposure time variation was y=8.2853+5.5878 ($R^2$=0.7287, $\sigma$=0.06, standard error=1.9%). In conclusion, cadmium sulfide responded linearly to the variation X-ray conditions, suggesting cadmium sulfide to be a feasible X-ray sensor of multi-function dosimeter related instruments.

• Journal of Energy Engineering
• /
• v.26 no.2
• /
• pp.99-120
• /
• 2017

In SS branch of Korea District Heating Corporation, Combined Heat & Power power plant with 99MW capacity and 98Gcal / h capacity is operated as a district electricity business. In this region, it is difficult to operate the generator due to the problem of surplus heat treatment between June and September due to the economic recession and the decrease in demand, so it is urgent to develop an economical energy new business model. In this study, we will develop an optimized operation model by introducing a renewable energy hybrid system based on actual operation data of this site. In particular, among renewable energy sources, fuel cell (Fuel Cell) power generation which can generate heat and electricity at the same time with limited location constraints, photovoltaic power generation which is representative renewable energy, ESS (Energy Storage System). HOMER (Hybrid Optimization of Multiple Energy Resources) program was used to select the optimal model. As a result of the economic analysis, 99MW CHP combined cycle power generation is the most economical in terms of net present cost (NPC), but 99MW CHP in terms of carbon emission trading and renewable energy certificate And 5MW fuel cells, and 521kW of solar power to supply electricity and heat than the supply of electricity and heat by 99MW CHP cogeneration power, it was shown that it is economically up to 247.5 billion won. we confirmed the results of the improvement of the zone electricity business condition by introducing the fuel cell and the renewable energy hybrid system as the optimization process model.

• Journal of the Korean Institute of Gas
• /
• v.13 no.2
• /
• pp.41-48
• /
• 2009

I collected the cases of CNG vehicle accidents which had happened for 30 years and analyzed the causes of the accidents according to each type of cylinders. There are about six accidents including three cylinder explosion accidents due to bad heat treatment, one composite damage, one CNG vehicle fire, and one fuel piping accident owing to the poor maintenance. When looking into the cylinder types involved in the accidents and the causes, 29% of the cylinder accidents are Type I and 24% Type IV, 16% Type II, and 14% Type III. 37% of the accidents are caused by the defects of the raw materials and the errors of a manufacturing process, 16% by the stress corrosion cracking as a result of the repetitive use, 15% by the cylinder's explosion on account of the malfunction of PRD(Pressure Relief Device) and the overpressure. The remainders of the causes are fire and unknown causes. Therefore, cylinder manufacturers have to strengthen quality management of raw materials and manufacturing process and painting regardless of each type of cylinder. Also bus operators need to make an effort to keep safety condition through every day check.

• Journal of Biomedical Engineering Research
• /
• v.31 no.3
• /
• pp.199-209
• /
• 2010

The locking compression plates-distal femur(LCP-DF) are being widely used for surgical management of the extra-articular complex fractures of the distal femur. They feature locking mechanism between the screws and the screw holes of the plate to provide stronger fixation force with less number of screws than conventional compression bone plate. However, their biomechanical efficacies are not fully understood, especially regarding the number of the screws inserted and their optimal configurations. In this study, we investigated effects of various screw configurations in the shaft and the condylar regions of the femur in relation to structural stability of LCP-DF system. For this purpose, a baseline 3-D finite element (FE) model of the femur was constructed from CT-scan images of a normal healthy male and was validated. The extra-articular complex fracture of the distal femur was made with a 4-cm defect. Surgical reduction with LCP-DF and bone screws were added laterally. To simulate various cases of post-op screw configurations, screws were inserted in the shaft (3~5 screws) and the condylar (4~6 screws) regions. Particular attention was paid at the shaft region where screws were inserted either in clustered or evenly-spaced fashion. Tied-contact conditions were assigned at the bone screws-plate whereas general contact condition was assumed at the interfaces between LCP-DF and bone screws. Axial compressive load of 1,610N(2.3 BW) was applied on the femoral head to reflect joint reaction force. An average of 5% increase in stiffness was found with increase in screw numbers (from 4 to 6) in the condylar region, as compared to negligible increase (less than 1%) at the shaft regardless of the number of screws inserted or its distribution, whether clustered or evenly-spaced. At the condylar region, screw insertion at the holes near the fracture interface and posterior locations contributed greater increase in stiffness (9~13%) than any other locations. Our results suggested that the screw insertion at the condylar region can be more effective than at the shaft during surgical treatment of fracture of the distal femur with LCP-DF. In addition, screw insertion at the holes close to the fracture interface should be accompanied to ensure better fracture healing.

• Journal of the Korean Dietetic Association
• /
• v.21 no.2
• /
• pp.91-109
• /
• 2015

The present study was conducted to provide the basis for improvement of clinical nutrition services through development of job standards of clinical dietitian for the clinical nutrition therapy to cancer patients in hospitals. Developing A Curriculum (DACUM) method was used for job analysis and development of job standards for clinical dietitians for cancer care. Based on DACUM analysis, information about duties, tasks, and task elements of clinical dietitians for cancer care was collected. Developed job standards were applied to clinical nutrition care for cancer patients in hospitals for evaluation. Based on DACUM analysis, consultations from professionals, and field application tests, the final job standards were composed of four duties, 18 tasks, and 56 task elements. The duties consisted of nutritional assessment, nutrition diagnosis, nutrition intervention, and nutrition monitoring evaluation. For cancer nutrition care, 109 work activities were developed. They were composed of 75 basic and 34 recommended work activities. The application of developed job standards for clinical dietitians for cancer care at 10 hospitals showed a performance rate of 72.3%. In conclusion, job standards for clinical dietitians for cancer care developed in this study might be effectively used as guidelines for providing clinical nutrition services for cancer patients in hospitals.

• Journal of Korean Foot and Ankle Society
• /
• v.12 no.2
• /
• pp.197-202
• /
• 2008

Purpose: Haglund's disease represents a painful heel caused by mechanically induced inflammation of the retrocalcaneal bursa and insertional Achilles tendinosis may coexist. Traditional open surgery can cause complications such as skin breakdown, painful scar and altered sensation around the heel. Endoscopic treatment offers the advantages that are related to minimally invasive procedure and we evaluate the clinical results and operative techniques of endoscopic decompression of retrocalcaneal space for Haglund's disease. Materials and Methods: Our retrospective study included seven heels in six consecutive patients for which nonoperative treatment had failed and endoscopic decompression was performed. The mean age was forty-one years (range, 28 to 53 years). All of the patients had typical complaints of inflammation of the retrocalcaneal bursa and Fowler-Philip angle of more than $75^{\circ}$ and positive parallel pitch lines were present on the lateral calcaneal radiograph. The endoscopic procedure consists of the resection of inflamed retrocalcaneal bursa and enough bone to prevent impingement of the bursa between the calcaneus and Achilles tendon. All patients were evaluated with radiologic angle, visual analogue scale (VAS) for pain and Ogilvie-Harris functional score. The mean follow-up was 18 months (range, 15 to 21 months). Results: The mean operation time was 61 minutes (range, 50 to 85 minutes). VAS for pain and Fowler-Philip angle were decreased from preoperative 8.7 and $82^{\circ}$ to postoperative 2.3 and $57^{\circ}$, respectively. One patient with ankylosing spondylitis had a fair result, 2 patients had good results and the remaining 3 patients had excellent results according to Ogilvie-Harris functional score. There were no surgical complications such as infection, Achilles tendon avulsion or abnormal heel sensation. Conclusion: The endoscopic decompression for Haglund's disease was demonstrated to have several advantages including low morbidity, allowance of functional rehabilitation, short recovery time and quick sports resumption. However a comparative study is needed to determine the value of endoscopic decompression and particular caution should be exerted for the enthesiopathy.

• The Journal of the Korean Society for Microbiology
• /
• v.35 no.3
• /
• pp.203-214
• /
• 2000

Porphyromonas gingivalis has been implicated in periodontal diseases. Accumulating evidence suggests that cardiovascular disease is the most prevalent medical problem in patients with periodontal diseases. In order to check the possibility that P. gingivalis is involved in coronary heart disease, the present study was performed to observe P. gingivalis adherence and invasion of human coronary artery endothelial cells (HCAEC) and production of cytokines and growth factors by HCAEC upon P. gingivalis infection. $^3H$-labeled P. gingivalis 381 was incubated with HCAEC for 90 min. The radioactivity of the washed HCAEC was a measure of the absorbed (adhering and invading) P. gingivalis. The absorption radioactivity of the HCAEC infected by P. gingivalis was determined to be 59.58% of the input bacterial cells. In contrast, the absorption radioactivity of the cells infected by S. gordonii Challis which was employed as a control was negligible (0.59%). DPG3, a P. gingivalis mutant defective of fimbriae, appeared to be impaired to some extent in capability of adherence/invasion as compared to that of the parental strain 381, showing 43.04% of the absorption radioactivity. The absorption radioactivity of the HCAEC infected by P. gingivalis 381 in the presence of excessive fimbriae at the concentrations of $50\;{\mu}g$ and $100\;{\mu}g/ml$ was 57.27 and 45.44%, respectively. Invasion of HCAEC by P. gingivalis 381 was observed by an antibiotic (metronidazole) protection assay and transmission electron microscopy (TEM). In the antibiotic protection assay, invasion by the bacterium was measured to be 0.73, 1.09, and 1.51% of the input bacterial cells after incubation for 30, 60, and 90 min, respectively. Invasion by DPG3 was shown to be 0.16% after 90-min incubation. In comparison of invasion efficiency at 90 min of the incubation, the invasion efficiency of DPG3 was 0.37% while that of its parental strain 381 was 2.54%. The immunoblot analysis revealed fimbriae of P. gingivalis did not interact with the surface of HCAEC. These results suggest that fimbriae are not the major contribution to the adherence of P. gingivalis to HCAEC but may be important in the invasion of HCAEC by the bacterium. The presence of cytochalasin D ($1\;{\mu}g/ml$) and staurosporine ($1\;{\mu}M$) reduced the invasion of HCAEC by P. gingivalis 381 by 78.86 and 53.76%, respectively, indicating that cytoskeletal rearrangement and protein kinase of HCAEC are essential for the invasion. Infection of P. gingivalis induced HCAEC to increase the production of TNF-${\alpha}$. by 60.6%. At 90 min of the incubation, the HCAEC infected with P. gingivalis cells was apparently atypical in the shape, showing loss of the nuclear membrane and subcellular organelles. The overall results suggest that P. gingivalis may cause coronary heart disease by adhering to and invading endothelial cells, and subsequently damaging the cells.