• Journal of the Korean Arthroscopy Society
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• v.17 no.1
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• pp.31-37
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• 2013

Purpose: This study performed to compare degree of joint stiffness and clinical results between early and delayed reconstruction of acute posterior cruciate ligament (PCL) injuries. Materials and Methods: Thirty-two Patients who underwent PCL reconstruction between March 2008 and October 2011 enrolled this study. We performed transtibial single bundle reconstruction using the allo-achilles tendon in all cases. We divided the patient into two groups, early reconstruction group underwent surgery before a week, delayed reconstruction group underwent surgery after 3 weeks, before 6 weeks. All the patients underwent aggressive joint motion exercise till surgery and enrolled post operative rehabilitation program. We checked posterior drawer stress radiography, range of motion, the Lysholm score, the International Knee Documentation Committee (IKDC) score and the Tegner score to evaluate the results. Results: At the final follow up the Lysholm score was 92.1 in the early group and 93.8 in the delayed group. All the cases were rated above B (near normal) on IKDC score (p=0.808, p=0.722). The Tegner score was 6.6 in the early reconstruction group and 6.2 in the delayed group (p=0.480), The average of maximum flexion and extension angle was $133.9^{\circ}$, $1.4^{\circ}$ in the early group and $133.6^{\circ}$, $1.1^{\circ}$ in the delayed group (p=0.560, p=0.581), no complication such as deep vein thrombosis or infection, no difference in posterior drawer stress radiography (p=0.750). Conclusion: We could obtain satisfactory clinical results in both the early and delayed reconstruction groups of acute PCL injuries. Therefore, the early reconstruction of PCL performed before a week could be one of the treatment options for acute PCL injury.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.4
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• pp.348-353
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• 2008

Oxygen isotope has not been used actively in water mass studies because of difficulties on the analysis though it has advantages as a water mass tracer. The most popular method to analysis the oxygen isotope ratio in water samples is equilibration method: isotopic equilibrium of water with $CO_2$ at constant temperature. The precision of oxygen isotope analysis using commercial automatic $H_2O/CO_2$ equilibrator is ${\pm}0.1%o$. This value is not sufficient for studies in open ocean. The object of this study is to improve the analytical precision enough to apply open ocean studies by modification of the instrument. When sample gas is transferred by the pressure difference, the fractionation which is preferential transportation of light isotope can be occurred since the long transportation path between the equilibrator and mass spectrometer. And the The biggest source of error during the analysis is long distance and large volume of the pathway of sample gas between. Therefore, liquid nitrogen trap and high vacuum system are introduced to the system. The precisions of 14 time analysis of same seawater sample are ${\pm}0.081%o$ and ${\pm}0.021%o$ by built-in system and by modified system in this study, respectively.

• Journal of Korea Technology Innovation Society
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• v.10 no.1
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• pp.73-97
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• 2007

R&D into future technologies should be conducted in conjunction with technological innovation strategies that are linked to corporate survival within a framework of information and knowledge-based competitiveness. As such, future technology strategies should be ensured through open R&D organizations. The development of future technologies should not be conducted simply on the basis of future forecasts, but should take into account customer needs in advance and reflect them in the development of the future technologies or services. This research aims to select as segmentation variables the customers' attitude towards accepting future telecommunication technologies and their value orientation in their everyday life, as these factors wilt have the greatest effect on the demand for future telecommunication services and thus segment the future telecom service market. Likewise, such research seeks to segment the market from the stage of technology R&D activities and employ the results to formulate technology development strategies. Based on the customer attitude towards accepting new technologies, two groups were induced, and a hierarchical customer segmentation model was provided to conduct secondary segmentation of the two groups on the basis of their respective customer value orientation. A survey was conducted in June 2006 on 800 consumers aged 15 to 69, residing in Seoul and five other major South Korean cities, through one-on-one interviews. The samples were divided into two sub-groups according to their level of acceptance of new technology; a sub-group demonstrating a high level of technology acceptance (39.4%) and another sub-group with a comparatively lower level of technology acceptance (60.6%). These two sub-groups were further divided each into 5 smaller sub-groups (10 total smaller sub-groups) through two rounds of segmentation. The ten sub-groups were then analyzed in their detailed characteristics, including general demographic characteristics, usage patterns in existing telecom services such as mobile service, broadband internet and wireless internet and the status of ownership of a computing or information device and the desire or intention to purchase one. Through these steps, we were able to statistically prove that each of these 10 sub-groups responded to telecom services as independent markets. We found that each segmented group responds as an independent individual market. Through correspondence analysis, the target segmentation groups were positioned in such a way as to facilitate the entry of future telecommunication services into the market, as well as their diffusion and transferability.

• Journal of Korea Water Resources Association
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• v.40 no.9
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• pp.697-707
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• 2007

In this study, we estimated the PMP(Probable Maximum Precipitation) and its transition in case of the typhoon Rusa which happened the biggest damage of all typhoons in the Korea. Specially, we analysed the moisture maximizing rate under the consideration of meteorological condition based on the orographic property when it hits in Gangneung region. The PMP is calculated by the rate of the maximum persisting 12 hours 1000 hPa dew points and representative persisting 12 hours 1000 hPa dew point. The former is influenced by the moisture inflow regions. These regions are determined by the surface wind direction, 850 hPa moisture flux and streamline, which are the critically different aspects compared to that of previous study. The latter is calculated using statistics program (FARD2002) provided by NIDP(National Institute for Disaster Prevention). In this program, the dew point is calculated by reappearance period 50-year frequency analysis from 5% of the level of significant when probability distribution type is applied extreme type I (Gumbel distribution) and parameter estimation method is used the Moment method. So this study indicated for small basin$(3.76km^2)$ the difference the PMP through new method and through existing result of established storm transposition and DAD(Depth-Area-Duration). Consequently, the moisture maximizing rate is calculated in the moisture inflow regions determined by meteorological fields is higher $0.20{\sim}0.40$ range than that of previous study. And the precipitation is increased $16{\sim}31%$ when this rate is applied for calculation.

• The Korean Journal of Nuclear Medicine
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• v.38 no.5
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• pp.338-343
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• 2004

Purpose: The purpose of this study was to develop a small animal PET using dual layer phoswich detector to minimize parallax error that degrades spatial resolution at the outer part of field-of-view (FOV). Materials and Methods: A simulation tool GATE (Geant4 Application for Tomographic Emission) was used to derive optimal parameters of small PET, and PET was developed employing the parameters. Lutetium Oxyorthosilicate (LSO) and Lutetium-Yttrium Aluminate-Perovskite(LuYAP) was used to construct dual layer phoswitch crystal. $8{\times}8$ arrays of LSO and LuYAP pixels, $2mm{\times}2mm{\times}8mm$ in size, were coupled to a 64-channel position sensitive photomultiplier tube. The system consisted of 16 detector modules arranged to one ring configuration (ring inner diameter 10 cm, FOV of 8 cm). The data from phoswich detector modules were fed into an ADC board in the data acquisition and preprocessing PC via sockets, decoder block, FPGA board, and bus board. These were linked to the master PC that stored the events data on hard disk. Results: In a preliminary test of the system, reconstructed images were obtained by using a pair of detectors and sensitivity and spatial resolution were measured. Spatial resolution was 2.3 mm FWHM and sensitivity was 10.9 $cps/{\mu}Ci$ at the center of FOV. Conclusion: The radioactivity distribution patterns were accurately represented in sinograms and images obtained by PET with a pair of detectors. These preliminary results indicate that it is promising to develop a high performance small animal PET.

• Tuberculosis and Respiratory Diseases
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• v.40 no.5
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• pp.565-574
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• 1993

Background: Pulmonary hamartomas are benign tumors that occur in the parenchyma or in the bronchi. They present as a solitary pulmonary nodule(SPN) or as a cause of bronchial obstruction. The incidence, once minimal, is increasing in Korea. To get clinical spectrum about the tumor, we analyzed all the reported cases in Korea since 1964. Methods: We reviewed the clinical, radiological and pathological findings of 13 patients of intrapulmonary or endobronchial hamartomas in Severance Hospital and of 38 reported cases in Korea published in literatures from 1964 to 1992 retrospectively. Results: Including 17 endobronchial hamartomas, 54 cases were studied. There were 25 men and 29 women, with a mean age of 47.2 years; 45.3 years in endobronchial type and 51.3 years in parenchymal type. Pulmonary symptoms were present in 8 patients (22%) of intrapulmonary type and in all patients of endobronchial type: cough (65%), dyspnea (53%), sputum (35%), fever (29%) in order. On chest X-rays, atelectasis was seen in 10 patients (59%) in endobronchial type; but SPN was noted in 36 patients (97%) of intrapulmonary type. Calcification was present in 7 intapulmonary hamartomas (23%); but is in 2 endobronchial hamartomas (12%). The diagnostic yield was 6 out of 14(43%) in endobronchial ones; 4 out of 7(57%) in intrapulmonary ones. Fifty patients underwent operations as follows: lobectomy (28), enucleation (8), resection (8), bilobectomy (4), pneumonectomy (2). The hamartomas were 1.2 times more common in the right lung; mean transverse diameter at the time of operation was 2.3 cm in endobronchial type, 3.8 cm in intrapulmonary ones. Chondroid components were present in 11(65%) of 17 endobronehial ones but in 30(91%) of 33 intrapulmonary hamartomas. No malignant changes were seen perioperative period and up to early 1993. Conclusion: The younger age in endobronchial hamartomas, the preponderance of the female sex and the more incidence in the right lung, and the diagnostic choice of lobectomies were different from the studies of the Western countries.

• Korean journal of food and cookery science
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• v.20 no.1
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• pp.1-10
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• 2004

This study was executed to find the effects of dietary control and oral health care on dental caries and oral problems in elementary school students, including the effects of nutritional and oral health education on the prevention of dental caries. 1. The oral health study found that 88.9％ of students brushed their teeth everyday, 63.7％ 2 times a day, and 50.4％ in the morning and at night. 2. According to the general characteristics whether or not, the female students had more dental caries than the males, and 29.1％ of the students that had dental caries ate snacke 1 or 2 times a day. 3. After the nutritional education, more students brushed their teeth in the after meal 4. According to gender, grade and nutritional education for oral health care, male students and higher grade students were more aware that “brushing teeth after meals is better than before”. The male and higher grade students, after the nutritional education, were more aware that “Bones and teeth are made from calcium”, and “Fluorine prevents teeth from dental caries” and the differences between the genders were statistically significant in relation to both these facts (p〈0.05) and before and after education (p〈0.01). The male and higher grade students, and those nutritionally educated were more conscious that “vegetables and fruits are good for teeth”, with the differences before and after the nutritional education were statistically significant (p〈0.05). The male and higher grade students were well aware that “Foods that have sugar cause dental caries”, and significant differences were shown between grades (p〈0.05). The male and higher grade students, after the nutritional education and were well aware that “Milk is good for teeth”, with a significant gender difference (p〈0.05). The female and higher grade students, and those after nutritional education were well aware that “Dental caries can not be perfectly cured once it had already occurred”. after nutrition, but not much differences.

• Pediatric Infection and Vaccine
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• v.8 no.2
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• pp.199-205
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• 2001

Purpose : Since the first report of vancomycin-resistant enterococci(VRE) in 1986, the resistance to vancomycin in enterococci has been increasingly rapidly. In this study, we investigated the clinical manifestations of pediatric patients with VRE and the pattern of the antibiotic use with increasing the rate of VRE in pediatrics Methods : We studied retrospectively 36 pediatric patients who were isolated VRE from January 1998 to December 2000. We classified patients into ICU and non ICU groups and reviewed species of VRE, specimens in which VRE were first detected and procedures performed before VRE detected. Results : We have found that the number of pediatric patients isolated VRE is increasingly annually in this study. In addition, the number of VRE-isolation in the ICU group and in patients who were operated or who underwent active procedures is much higher than that of in the non ICU group and in patients who were taken medication only. Enterococcus faecium is the main species of VRE. VRE showed high resistance to almost all antibiotics except tetracycline, and resistance was closely related to the duration of hospitalization and history of the antibiotic use. The proportion of the cephalosporin use was higher than any other antibiotic before VRE detection. In contrast, that of teicoplanin was higher than any other antibiotic after VRE detection(P<0.05). The cases of superinfection is higher in the ICU group than in non ICU group. Conclusion : In the hospital level, prevention of nosocomial infection through proper administrative policies, through surveillance of high risk VRE regions and prudent antibiotic use can prevent VRE outbreaks and corresponding side effects.

• Journal of Korean Society of Transportation
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• v.19 no.4
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• pp.35-47
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• 2001

Traffic represents one of the largest sources of primary air pollutants in urban area. As a consequence. numerous abatement strategies are being pursued to decrease the ambient concentration of pollutants. A characteristic of most of the these strategies is a requirement for accurate data on both the quantity and spatial distribution of emissions to air in the form of an atmospheric emission inventory database. In the case of traffic pollution, such an inventory must be compiled using activity statistics and emission factors for vehicle types. The majority of inventories are compiled using passive data from either surveys or transportation models and by their very nature tend to be out-of-date by the time they are compiled. The study of current trends are towards integrating urban traffic control systems and assessments of the environmental effects of motor vehicles. In this study, a methodology of motor vehicle emission calculation by using real-time traffic data was studied. A methodology for estimating emissions of CO at a test area in Seoul. Traffic data, which are required on a street-by-street basis, is obtained from induction loops of traffic control system. It was calculated speed-related mass of CO emission from traffic tail pipe of data from traffic system, and parameters are considered, volume, composition, average velocity, link length. And, the result was compared with that of a method of emission calculation by VKT(Vehicle Kilometer Travelled) of vehicles of category.

• Korean Journal of Environmental Agriculture
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• v.19 no.3
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• pp.194-200
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• 2000

The amount of swine wastewater reaches about $197,000m^3$ per day at live-stock houses in the whole country. A half of the swine wastewater resources are too small to be restricted legally. This untreated wastewater causes the eutrophication in the water bodies. In case of swine wastewater treatment, the solid-liquid separation must be performed because feces(solid phase) and urine(liquid phase) have large differences in nitrogen and phosphorus concentration. It is necessary to assess exactly the concentration of the pollutants in swine wastewater for planning the wastewater treatment facilities. A full-scale operation was carried out in K city and the plant is consists of conventional plant, the supplementary flocculation basin of chemical treatment process and $anaerobic{\cdot}aerobic$ basin for nitrogen removal. The improved full-scale swine wastewater treatment plant removed the $1,500{\sim}3,000mg/l$ of total-nitrogen(T-N) to 120mg/l of T-N and $131{\sim}156mg/l$ of total-phosphorus(T-P) to $0.15{\sim}1.00mg/l$ of T-N. Accordingly, as a results of operational improvement, the removal efficiencies of T-N and T-P were over $92{\sim}96%$, 99%, respectively. The continuous supply of organic carbon sources and the state of pH played important roles for the harmonious metabolism in anaerobic basin and the pH value of anaerobic basin maintained at about 9.0 for the period of the study.