• The Journal of the Korean bone and joint tumor society
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• v.10 no.2
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• pp.79-87
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• 2004

Purpose: The recent development of MR has made to possible radiological diagnosis in various soft tssue tumors. But multifarious components within soft tissue tumors and their periodic change have made to difficult even differentiation of malignant from benign soft tissue tumors solely on the MR. So authors retry to differentiate malignant from benign soft tissue tumors with clinical and MR finding complex. Materials and methods: We were analysed 82 pathologically confirmed soft tissue solid tumors (37 cases as malignancy including intermediate tumors and 45 cases as benign including inflammatory masses) which are correlated with clinical findings such as age, size, and location, MR findings such as tumor border, texture on T2 and contrast-T1 images, and enhancement area retrospectively. Many typical lipoma and cysts including of ganglion and abscess are rejected in the benign soft tissue tumor group because not difficult to diagnose on MR. Results: Malignant soft tissue tumors were more frequent in 21~40 and 61~80 years old of the age, above 3.0 cm of the size, trunk-pelvis-lower extremities of the location, and MR findings with irregular border and above 50% of the enhancement area than those of benign soft tissue tumors. Conclusion: The clinical finding that divided to two locations as trunk-pelvis-lower extremities and upper extremities-shoulder-spine was statistically significant to differentiate malignant from benign soft tissue solid tumors. However, the others would provide some useful informations to differentiate them never specific.

• The Journal of the Korean bone and joint tumor society
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• v.15 no.2
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• pp.122-129
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• 2009

Purpose: To evaluate treatment outcomes of malignant melanoma and to analyze the factors that contributes to outcomes. Materials and Methods: We reviewed the 51 cases of malignant melanoma from March, 1997 to March, 2004 and were followed up more than 5 years. Average age was 49.4. We compared 5-year survival rate for each age, gender, site of occurrence, depth of tumor, metastasis of regional lymph node and immuno-chemo therapy. Results: 5-year survival rate was 88.5% for the age group below 65, 88.0% for the age group 65 and above, 62.5% for male and 100% for female. 5-year survival rate for the site of occurrence showed 100% in upper extremities, and 80.0% in lower extremities and 100% in other sites. 5-year survival rate was 100% for the stage below Clark stage III and 79.3% for the stage above IV. In surgical resection, 5-year survival rate was 66.7% for lymph node metastasis group and 94.9% for non-lymph node metastasis group. Conclusion: The prognostic factors of malignant melanoma were gender, tumor site, depth of tumor (Clark's stage) and metastasis of regional lymph node. But, there was no relation between the age and the survival rate in our study.

• The Journal of the Korean bone and joint tumor society
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• v.15 no.2
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• pp.104-110
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• 2009

Purpose: Compared to soft tissue sarcoma, the relative risk of extraskeletal osteosarcoma is still not clear. The purpose of this study is to identify the difference in survival and local recurrence rate between two soft tissue sarcomas. Materials and Methods: Twelve patients with pathologically confirmed extraskeletal osteosarcoma were analysed. For retrospective matched case-control study, we selected 72 patients who were confirmed as high grade soft tissue sarcoma and had similar tumor location, tumor size and age to extraskeletal osteosarcoma. Results: Median age was 50 years old. Five cases were located in upper extremity, four in the buttocks, three in the lower extremity. Overall survival rate of extraskeletal osteosarcoma group and high grade soft tissue sarcoma group at 5 years were 52% and 55%. There is no significant difference (p=0.8). Local recurrence rate and metastasis rate were 58%, 67% in extraskeletal osteosarcoma group and 36%, 51% in soft tissue sarcoma group, which were not stastistically significant(p=0.2, p=0.4). Conclusion: Extraskeletal osteosarcoma have similar local recurrence, metastasis and survival rate compare to high grade soft tissue sarcoma. The number of patients of this study were too small to identify outcome of extraskeletal osteosarcoma. Further multi-institutional study should be attempted.

• The Journal of the Korean bone and joint tumor society
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• v.17 no.1
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• pp.30-35
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• 2011

Purpose: This study was designed to evaluate the treatment results of malignant melanoma and to analyze the factors influencing prognosis. Materials and Methods: Thirty one cases of malignant melanoma were included in this study. They were treated in our hospital surgically, medically and immunologically from January 1996 to December 2005, and were followed more than 5 years. We compared 5 year survival rate (5YSR) according to the age, gender, anatomical site, depth of tumor, TNM stage, involvement of lymph node and immuno-chemotherapy. Results: Overall 5YSR was 80.6%. 5YSR of the age group below 65 years was 89.7% and 66.7% for the age group over 65 (p=0.033). 5YSR for men was 75% and 90.9% for women. 5YSR according to the site of occurrence showed 66.7% in upper extremities, 89.5% in lower extremities, and 66.7% in other site. 5YSR was 100% for the Clark level below III and 62.5% for the level above IV (p=0.032). 5YSR was 53.8% for lymph node metastasis group and 100% for non-lymph node metastasis group (p=0.021). Conclusion: We concluded that early diagnosis and wide excision was the most important in treatment of malignant melanoma. The prognostic fractors of malignant melanoma were age, depth of tumor (Clark's stage) and metastasis of lymph node.

• The Journal of Engineering Geology
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• v.25 no.1
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• pp.115-129
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• 2015

The cut-slope of a large-sectional tunnel portal is recognized as a potential area of weakness due to unstable stress distribution and possible permanent displacement. This paper presents a case study of a slope failure and remediation for a large-scale cut-slope at a tunnel portal. Extensive rock-slope brittle failure occurred along discontinuities in the rock mass after 46 mm of rainfall, which caused instability of the upper part of the cut-slope. Based on a geological survey and face mapping, the reason for failure is believed to be the presence of thin clay fill in discontinuities in the weathered rock mass and consequent saturationinduced joint weakening. The granite-gneiss rock mass has a high content of alkali-feldspar, indicating a vulnerability to weathering. Immediately before the slope failure, a sharp increase in displacement rate was indicated by settlement-time histories, and this observation can contribute to the safety management criteria for slope stability. In this case study, emergency remediation was performed to prevent further hazard and to facilitate reconstruction, and counterweight fill and concrete filling of voids were successfully applied. For ultimate remediation, the grid anchor-blocks were used for slope stabilization, and additional rock bolts and grouting were applied inside the tunnel. Limit-equilibrium slope stability analysis and analyses of strereographic projections confirmed the instability of the original slope and the effectiveness of reinforcing methods. After the application of reinforcing measures, instrumental monitoring indicated that the slope and the tunnel remained stable. This case study is expected to serve as a valuable reference for similar engineering cases of large-sectional slope stability.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.4
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• pp.239-247
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• 2013

Recently renewable energy such as offshore wind energy takes a higher interest due to the depletion of fossil fuel and the environmental pollution. This paper deals with multi-body dynamics (MBD) analysis technique for offshore wind turbine system considering aerodynamic loads and Thevenin equation used for determination of electric generator torque. Dynamic responses of 5MW offshore wind turbine system are evaluated via the MBD analysis, and the system is the horizontal axis wind turbine (HAWT) which generates electricity from the three blades horizontally installed at upwind direction. The aerodynamic loads acting on the blades are computed by AeroDyn code, which is capable of accommodating a generalized dynamic wake using blade element momentum (BEM) theory. In order that the characteristics of dynamic loads and torques on the main joint parts of offshore wind turbine system are simulated similarly such an actual system, flexible body modeling including the actual structural properties are applied for both blade and tower in the multi-body dynamics model.

• Journal of the Korean Society of Food Culture
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• v.27 no.4
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• pp.407-413
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• 2012

In previous studies, we performed joint animal studies and clinical trials between Yonsei University and Oryza Oil & Fat Chemical Co. Ltd. We have shown that coffee bean extract has potent anti-obesity and hypotriglyceridemic activities as well as beneficial effects on body fat reduction.In this study, the effects of coffee bean extract (100 mg/capsule) on body fat reduction were evaluated in overweight/obese women (body mass index of 25~30 $kg/m^2$ or body fat > 30%) not diagnosed with any type of disease. Subjects were randomly assigned to a coffee bean extract group (n=10) or placebo group (n=10). We measured anthropometric parameters, abdominal fat distribution by computed tomography and blood components before and after the 8week intervention period. After supplementation, the coffee bean extract group showed body weight (p=0.08), body mass index (p=0.06), hip circumference (p<0.05), and upper waist circumference (p< 0.01). In addition, after 8 weeks, the coffee bean extract group showed a significant decrease in abdominal internal fat area compared to 0 weeks (0 weeks : $155.8cm^2$; 8 weeks : $145.9cm^2$, ${\Delta}$ change : $-9.9cm^2$, respectively). However, there were no significant differences in lipid profiles or serological measurements between the coffee bean extract group and placebo group. The results of our human study demonstrated that coffee bean extract supplementation for 8 weeks has beneficial effects on reducing abdominal internal fat area as well as hip and waist circumferences.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1334-1343
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• 2008

Growing needs for efficient management of water resources urge the joint operation of dams and integrated management of whole basin. As one of the tools for supporting above tasks, this study aims to constitute a hydrologic model that can simulate the streamflow discharges at some control points located both upper and down stream of dams. One of the currently available models is being studied to be applied with a least effort in order to support the ongoing project of KWATER (Korea Water Resources Corporation), "Establishment of integrated operation scheme for the dams in Han River Basin". On this study, following works have been carried out : division of Han River Basin into 24 sub-basins, use of rainfall data of 151 stations to make spatial distribution of rainfall, selection of control points such as Soyanggang Dam, Chungju Dam, Chungju Release Control Dam, Heongseong Dam, Hwachun Dam, Chuncheon Dam, Uiam Dam, Cheongpyung Dam and Paldang Dam, selection of SSARR (Streamflow Synthesis and Reservoir Regulation) model as a hydrologic model, preparation of input data of SSARR model, sensitivity analysis of parameter using hydrologic data of 2002. The sensitivity analysis showed that soil moisture index versus runoff percent (SMI-ROP), baseflow infiltration index versus baseflow percent (BII-BFP) and surface-subsurface separation (S-SS) parameters are higher sensitive parameters to the simulation result.

• Journal of radiological science and technology
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• v.32 no.1
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• pp.69-78
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• 2009

The cardiovascular disease has been known as a common cause of death for a long time in the west. The eating habits of Asia, including Korea, have changed recently, so that this disease is also a problem in Asia now. Annual Report on the Cause of Death Statistics from 1996 to 2006 reported that the cardiovascular disease would become the number one cause of death in the next $5{\sim}10$ years. Therefore we realize that more accurate examination is required. The aim of this study was to investigate the accuracy of Calcium-scoring CT and the relationship between risk factor and quantitative scores of Calcium-scoring CT. Through this study we expect that the national public health will be improved. Seventy patients with chest pain were chosen at random. The patients were undergone both coronary CT antigraphy and Calcium - scoring CT at G hospital in Incheon from February 1 to June 30, 2008. The result of the Calcium-scoring CT showed its usefulness for Ischemic cardiovascular disease, with an accuracy similar to that of exercise/pharmacologic stress or ECG when it is difficult for a patient to exercise due to joint problems, aging or for other reasons.

• Korean Journal of Applied Biomechanics
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• v.16 no.3
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• pp.137-148
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• 2006

The purpose of this study was to compare muscle activity in the lower extremity during walking wearing jogging and roller shoes. Twelve male middle school students (age: 15.0 yrs, height 173.7 cm, weight 587.7 N) who have no known musculoskeletal disorders were recruited as the subjects. Seven pairs of surface electrodes (QEMG8, Laxtha Korea, gain = 1,000, input impedance >$1012{\Omega}$, CMMR >100 dB) were attached to the right-hand side of the body to monitor the rectus femoris (RF), vastus medialis (VM), vastus lateralis (VL), biceps femoris (BF), tibialis anterior (TA), and medial (GM) and lateral gastrocnemius (GL) while subjects walked wearing roller and jogging shoes in random order at a speed of 1.1 m/s. An event sync unit with a bright LED light was used to synchronize the video and EMG recordings. EMG data were filtered using a 10 Hz to 350 Hz Butterworth band-passdigital filter and further normalized to the respective maximum voluntary isometric contraction EMG levels. For each trial being analyzed, five critical instants and four phases were identified from the recording. Averaged IEMG and peak IEMG were determined for each trial. For each dependent variable, paired t-test was performed to test if significant difference existed between shoe conditions (p<.05). The VM, TA, BF, and GM activities during the initial double limb stance and the initial single limb stance reduced significantly when going from jogging shoe to roller shoe condition. The decrease in EMG levels in those muscles indicated that the subjects locked the ankle and knee joints in an awkward fashion to compensate for the imbalance. Muscle activity in the GM for the roller shoe condition was significantly greater than the corresponding value for the jogging shoe condition during the terminal double limb stance and the terminal single limb stance. Because the subjects tried to keep their upper body weight in front of the hip to prevent falling backward, the GM activity for the roller shoe condition increased. It seems that there are differences in muscle activity between roller shoe and jogging shoe conditions. The differences in EMG pattern may be caused primarily by the altered position of ankle, knee, and center of mass throughout the walking cycle. Future studies should examine joint kinematics during walking with roller shoes.