• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.5
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• pp.1-13
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• 2016

This study aims to observe the impacts of entrepreneurship and market orientation of Seoul's business incubator (BI) CEO's on business performance, as well as investigate the moderating effects of BI supporting services. The main objectives of this study are as follows: first, to observe how the entrepreneurship of CEO's affects business performance; second, to observe how CEO's market orientation as a cultural factor attributes to business performance; third, to verify whether the utilization level of BI supporting services shows moderating effects between entrepreneurship and business performance, and finally to verify whether the utilization level of BI supporting services shows moderating effects between market orientation and business performance. Business incubators in Seoul registered with the Business Incubator Association were surveyed both online and offline to receive 127 responses out of 320 circulations. By filtering out insincere reponses, 117 were used for statistical analysis. Our results assert that the utilization level of physical BI supporting services does indeed strengthen the relation between initiative and financial performance. Also, it is interesting to note that the utilization level of physical BI supporting services supports the relation between risk sensitivity and financial performance. While risk sensitivity on its own shows no positive effect on business performance, a suitable utilization level of BI supporting services is likely to strengthen the connection. In addition, the utilization level of both physical and non-physical supporting services shows a moderating effect between initiative and non-financial performance. Based on the results above, risk-taking business incubator CEOs with initiative are likely to yield better financial performance in terms of increasing sales, if provided with various physical supporting services such as sufficient educational facilities including communal spaces and conference rooms.

• Radiation Oncology Journal
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• v.16 no.2
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• pp.159-165
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• 1998

Purpose : The best prognosis for hepatocellular carcinoma can be achieved with surgical resection. However, the number of resected cases is limited due to the advanced lesion or associated liver disease. A trial of combined transcatheter arterial chemoembolization(TACE) and local radiotherapy(RT) for unresectable hepatocellular carcinoma(HCC) was prospectively conducted and its efficacy and toxicity were investigated. Materials and Methods : From 1992 to 1994, 30 Patients with unresectable HCC due either to advanced lesion or to associated cirrhosis were entered in the study Exclusion criteria included the presence of extrahepatic metastasis, liver cirrhosis of Child's class C, tumors occupying more than two-thirds of the whole liver, and an ECOG scale of more than 3. Patient cHaracteristics were : mean tumor size $8.95\pm3.4cm$, serum AFP+ in all patients, portal vein thrombosis in all patients, liver cirrhosis in 22 patients, and UICC stage III and IVA in 10 and 20 patients, respectively. TACE was performed with the mixture of Lipiodol(5ml) and Adriamycin(50mg) and Gelfoam embolizatin. RT(mean dose $44.0\pm9.3Gy$) 10 days with conventional fractionation. Results : An objective response was observed in 19 patients($63.3\%$). Survival rates at 1 2, and 3 years were $67\%,\;33.3\%$ and $22.2\%$, respectively. Median survival was 17 months. There were 6 patients surviving more than 3 years. Distant metastasis occurred in 10 patients, with 8 in the lung only and 2 in both lung and bone, Toxicity included transient elevation of liver function test in all patients, fever in 20, thrombocytopenia in 4, and nausea and vomiting in 1. There was no treatment-related death. Conclusion : Combined TACE and RT appear to produce a favorable response and survival results with minimal toxicity.

• Journal of The Korean Association For Science Education
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• v.37 no.5
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• pp.825-833
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• 2017

The Korean Ministry of Education has emphasized human resource development with creative and convergent ability for future science and technology development. Korean STEAM Education aims to enhance students' interest and their understanding of science and technology as well as to develop students' creative problem-solving skills. Through STEAM R&E project, students experience self-directed research in order to solve the problem in the context of everyday life. In this study, we aim to find out whether the creative leader competency of high school students changed after they experienced the STEAM R&E project. The creative leader competency consisted of three domains: cognitive, affective, and societal domain. We measured the creative leader competency using the questionnaire scales. The questionnaire was administered to 612 high school students who participated in the 2016 STEAM R&E project. Pre- and post- test scores were collected, and we analyzed it. We compared the mean difference between pre- and post- test scores as well as the mean differences among science high school, gifted school, science core school, and general high school. From the result, we found that all student' creative leader competency improved after participating in the STEAM R&E project in all three domains. The result also showed that students' test scores of science high school and gifted school showed no significant mean differences, while student's scores of both science core school and general high school improved significantly. From the results, we concluded that STEAM R&E activities could be an effective tool in cultivating creative leader competency, especially for general high school students and science core school students. We also suggested that further researches are needed to find how we could enhance students' creative leader competency.

• Radiation Oncology Journal
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• v.16 no.1
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• pp.63-69
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• 1998

Purpose : This study is to evaluate the efficacy of small bowel displacement system(SBDS) in post-operative pelvic radiation therapy(RT) of rectal cancer patients by measurement of small bowel volume included in the radiation fields receiving therapeutic dose. Materials and Method : Ten consecutive new rectal cancer patients referred to the department of Radiation Oncology of Samsung Medical Center in May of 1997 were included in this study. All patients were asked to drink $Castrographin^(R)$ before simulation and were laid prone for conventional simulation and CT scans with and without SBDS. The volume of opacified small bowel on CT scans, which was to be included in the radiation fields receiving therapeutic dose, was measured using Picture archiving and communication system (PACS). Results : The average small bowel volumes with and without SBDS were 176.0ml(5.2-415.6ml) and 185.1ml(54.5-434.2ml), respectively The changes of small bowel volume with SBDS compared to those without SBDS were more than $10\%$ decrease in three, less than 10% decrease in two, less than $10\%$ increase in three, and more than $10\%$ increase in two patients. Conclusion : No significant advantage of using SBDS in post-operative pelvic RT for rectal cancer patients has been shown by small bowel volume measurement using CT scan considering additional effort and time needed for simulation and treatment setup.

• Journal of the Korean Society of Radiology
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• v.18 no.3
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• pp.187-201
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• 2024

Osteoporosis is a major health issue globally, often remaining undetected until a fracture occurs. To facilitate early detection, deep learning (DL) models were developed to classify osteoporosis using abdominal computed tomography (CT) scans. This study was conducted using retrospectively collected data from 3,012 contrast-enhanced abdominal CT scans. The DL models developed in this study were constructed for using image data, demographic/clinical information, and multi-modality data, respectively. Patients were categorized into the normal, osteopenia, and osteoporosis groups based on their T-scores, obtained from dual-energy X-ray absorptiometry, into normal, osteopenia, and osteoporosis groups. The models showed high accuracy and effectiveness, with the combined data model performing the best, achieving an area under the receiver operating characteristic curve of 0.94 and an accuracy of 0.80. The image-based model also performed well, while the demographic data model had lower accuracy and effectiveness. In addition, the DL model was interpreted by gradient-weighted class activation mapping (Grad-CAM) to highlight clinically relevant features in the images, revealing the femoral neck as a common site for fractures. The study shows that DL can accurately identify osteoporosis stages from clinical data, indicating the potential of abdominal CT scans in early osteoporosis detection and reducing fracture risks with prompt treatment.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.1
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• pp.95-107
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• 2017

In this study, a preliminary study was undertaken for development of a tunnel incident automatic detection system based on a machine learning algorithm which is to detect a number of incidents taking place in tunnel in real time and also to be able to identify the type of incident. Two road sites where CCTVs are operating have been selected and a part of CCTV images are treated to produce sets of training data. The data sets are composed of position and time information of moving objects on CCTV screen which are extracted by initially detecting and tracking of incoming objects into CCTV screen by using a conventional image processing technique available in this study. And the data sets are matched with 6 categories of events such as lane change, stoping, etc which are also involved in the training data sets. The training data are learnt by a resilience neural network where two hidden layers are applied and 9 architectural models are set up for parametric studies, from which the architectural model, 300(first hidden layer)-150(second hidden layer) is found to be optimum in highest accuracy with respect to training data as well as testing data not used for training. From this study, it was shown that the highly variable and complex traffic and incident features could be well identified without any definition of feature regulation by using a concept of machine learning. In addition, detection capability and accuracy of the machine learning based system will be automatically enhanced as much as big data of CCTV images in tunnel becomes rich.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.7
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• pp.2386-2396
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• 1996

A numerical simulation has been performed for isothermal and reacting flows in an exisymmetric, bluff-body research combustor. The present formulation is based on the density-weighted averaged Navier-Stokes equations together with a k-epsilon. turbulence model and a modified eddy-breakup combustion model. The PISO algorithm is employed for solution of thel Navier-Stokes system. Comparison between measurements and predictions are made for a centerline axial velocities, location of stagnation points, strength of recirculation zone, and temperature profile. Even though the numerical simulation gives acceptable agreement with experimental data in many respects, the present model is defictient in predicting the recoveryt rate of a central near-wake region, the non-isotropic turbulence effects, and variation of turbulent Schmidt number. Several possible explanations for these discrepancies have been discussed.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.353-360
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• 2017

In this study, the design and performance test of the air to water heat pump capable of producing hot water for greenhouse heating by using the surplus solar heat inside the greenhouse and the air heat outside greenhouse as the selective heat source were conducted. The heat storage operations using the surplus solar heat and the outside air heat were designed to be switched according to the setting temperature of the greenhouse in consideration of the optimum temperature range of the crop. In the developed system, it was possible to automatically control the switching of heat storage operation, heating and ventilation by setting 12 reference temperatures on the control panel. In the selective heat storage operation with the surplus solar heat and outside air heat, the temperature of thermal storage tank was controlled variably from $35^{\circ}C$ to $52^{\circ}C$ according to the heat storage rate and heating load. The heat storage operation times using the surplus solar heat and outside air heat were 23.1% and 30.7% of the experimental time respectively and the heat pump pause time was 46.2%. COP(coefficient of performance) of the heat pump of the heat storage operation using the surplus solar heat and outside air heat were 3.83 and 2.77 respectively and was 3.24 for whole selective heat storage operation. For the comparative experiment, the heat storage operation using the outside air heat only was performed under the condition that the temperature of the thermal storage tank was controlled constantly from 50 to $52^{\circ}C$, and COP was analyzed to be 2.33. As a result, it was confirmed that the COP of the heat storage operation using the surplus solar heat and outside air heat as selective heat source and the variable temperature control of the thermal storage tank was 39% higher than that of the general heat storage operation using the outside air heat only and the constant temperature control of the thermal storage tank.

• Journal of dental hygiene science
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• v.14 no.1
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• pp.43-50
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• 2014

The purpose of this study was to examine the influence of internal marketing activities on motivating dental hygienists in dental hospital in an effort to be of use for setting strategies geared toward boosting the productivity of dental hygienists. The findings of the study were as follows: Concerning internal marketing activities by general characteristics, the dental hygienists who received 4-year college or higher education received more education than the college graduates ($p{\leq}0.001$). As for the leave system, the dental hygienists who worked in general hospitals (p=0.011) and sited in Chungcheongnam-do ($p{\leq}0.001$) replied more leaves were provided. In terms of welfare benefits, there were significant differences in those regards according to the type of hospital (p=0.029) and service area ($p{\leq}0.001$). As to the reward system, their responses about this system were similar to their responses about education & training, leaves and welfare benefits. The motivating factors consisted of 6 motivation factors and 10 hygiene factors. The motivation factors included an opportunities to develop ability and appropriate training to their work. The hygiene factors involved implement of policies and procedures, work environments, relationship with colleagues. Regarding awareness of the motivation factors by general characteristics, there were differences in that aspect according to age (p=0.043), and their awareness of the hygiene factors was different according to service area (p=0.038). As a result of analyzing which factors affected motivating, the leave system (p=0.038) and communication (p=0.001) that belonged to the internal marketing activities were identified as the influential motivation factors. In terms of the hygiene factors, age and service area were influential among the general characteristics (p=0.047, p=0.045). Above findings of the study suggest that it will be possible for dental institutions to ensure successful management by conducting internal marketing activities tailored to the characteristics of their organizational members and by motivating dental hygienists especially through communication.

• Journal of Chest Surgery
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• v.35 no.5
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• pp.387-391
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• 2002

Background: Postoperative morbidity and mortality in destroyed lung are relatively high. We tried to identify the prognostic factors affecting postoperative morbidity and mortality in destroyed lung through a retrospective study. Material and method: The retrospective study was undertaken in 112 patients who had undergone pneumonectomy or pleuropneumonectomy for destroyed lung at Severance Hospital from 1970 to 2000. We analyzed the correlation between postoperative morbidity and mortality and etiology, duration of disease, preoperative FEV1, presence or absence of peroperative empyema, operation timing, the side of operation, duration of operation, and operation type. Result: There were 55 men and 57 women, aged 20 to 81 years (mean 44 years). Etiologic diseases were tuberculosis in 86 patients(76.8%) including tuberculos empyema in 20 and tuberculous bronchiectasis in 4, pyogenic empyema in 12(10,7%), bronchiectasis in 12(10.7%), and lung abscess in 2(1.8%). Postoperative morbidity were 25%(n=28) and postoperative mortality was 6%(n=7). The presence of preoperative empyema(p=0.016), pleuropneumonectomy(p=0.037) and preoperative FEV1 of less than 1.75 L(P=0.048) significantly increased the postoperative morbidity, If operation time was less than 300min, postoperative morbidity(p=0.002) and mortality(p=0.03) were significantly low. Conclusion: Postoperative morbidity and mortality in destroyed lung were acceptable. Postoperative morbidity and mortality were significantly low when operation time was less than 300 min. Preoperative existence of empyema, pleuropneumonectomy and preoperative FEV1 of less than 1.75 L significantly increased postoperative morbidity.