• Progress in Medical Physics
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• v.25 no.1
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• pp.23-30
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• 2014

The purpose of this study is to evaluate the developed dose verification program for in vivo dosimetry based on transit dose in radiotherapy. Five intensity modulated radiotherapy (IMRT) plans of lung cancer patients were used in the irradiation of a homogeneous solid water phantom and anthropomorphic phantom. Transit dose distribution was measured using electronic portal imaging device (EPID) and used for the calculation of in vivo dose in patient. The average passing rate compared with treatment planning system based on a gamma index with a 3% dose and a 3 mm distance-to-dose agreement tolerance limit was 95% for the in vivo dose with the homogeneous phantom, but was reduced to 81.8% for the in vivo dose with the anthropomorphic phantom. This feasibility study suggested that transit dose-based in vivo dosimetry can provide information about the actual dose delivery to patients in the treatment room.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.7
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• pp.486-494
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• 2009

One-dimensional modeling of $CH_4$/air premixed flame was conducted to validate the heat loss model and investigate NOx formation characteristics in the postflame region. The predicted temperature and NO concentration were compared to experimental data and previous heat loss model results using a constant gradient of temperature (100 K/cm). The following conclusions were drawn. In the heat loss model using steady-state heat transfer equation, the numerical results using the effective heat loss coefficient ($h_{eff}$) of $1.0\;W/m^2K$ were in very good agreement with the experiments in terms of temperature and NO concentration. On the other hand, the calculated values using the constant gradient of temperature (100 K/cm) were lower than that in the experiments. Although the effects of heat loss suppress NO production near the flame region, a significant difference in NO concentration was not found compared to that under adiabatic conditions. In the postflame region, however, there were considerable differences in NO emission index as well as the contribution of NO formation mechanisms. In particular, in the range of ${\phi}\;{\geq}\;0.8$, the prompt NO mechanism plays an important role in the NO reduction under the adiabatic condition. On the other hand, the mechanism contributes to the NO production under the heat loss conditions.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.9
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• pp.4377-4380
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• 2016

Background: To compare diagnostic performance in differentiating benign from malignant ovarian masses between IOTA (the International Ovarian Tumor Analysis) simple rules and subjective sonographic assessment. Materials and Methods: Women scheduled for elective surgery because of ovarian masses were recruited into the study and underwent ultrasound examination within 24 hours of surgery to apply the IOTA simple rules by general gynecologists and to record video clips for subjective assessment by an experienced sonographer. The diagnostic performance of the IOTA rules and subjective assessment for differentiation between benign and malignant masses was compared. The gold standard diagnosis was pathological or operative findings. Results: A total of 150 ovarian masses were covered, comprising 105 (70%) benign and 45 (30%) malignant. Of them, the IOTA simple rules could be applied in 119 (79.3%) and were inconclusive in 31 (20.7%) whereas subjective assessment could be applied in all cases (100%). The sensitivity and the specificity of the IOTA simple rules and subjective assessment were not significantly different, 82.9% vs 86.7% and 94.0% vs 94.3% respectively. The agreement of the two methods in prediction was high with a Kappa index of 0.835. Conclusions: Both techniques had a high diagnostic performance in differentiation between benign and malignant ovarian masses but the IOTA rules had a relatively high rate of inconclusive results. The IOTA rules can be used as an effective screening technique by general gynecologists but when the results are inconclusive they should consult experienced sonographers.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.3
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• pp.250-260
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• 2009

To improve work environment for health managers, it was investigated about effect of job stress, psychosocial stress and job satisfaction of health managers on job commitment. The sample used in this study consisted of 166 persons of industrial health managers. The data were collected with self-administered questionnaires between November 2007 and January 2008, and the results analyzed with ANOVA and multiple regression analysis. Job stress was evaluated by using a Korean Occupational Stress Scale(KOSS), and Psychosocial wellbeing index-Short Form(PWI-SF) was used for a psychosocial stress level evaluation. Organized commitment evaluated loyalty, compensation, welfare, job immersion, external employment opportunity, total agreement with employer and personal ability development. In path analyses, interpersonal conflict, lack of reward, psychosocial distress were associated with job satisfaction. And psychosocial distress, job demand, job insecurity, organizational system, occupational climate were associated with organizational commitment. In considering above findings, the health program for psychosocial distress, improvement of job demand, job insecurity, organizational system, occupational climate would be implemented to increase organizational commitment of Health manager.

• Wind and Structures
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• v.24 no.1
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• pp.1-24
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• 2017

Wind environment in urban residential areas is an important index to consider when evaluating the living environment. However, due to the complexity of the flow field in residential areas, it is difficult to specify the correct inflow boundary conditions in the large eddy simulation (LES). In this paper, the weighted amplitude wave superposition (WAWS) is adopted to simulate the fluctuating velocity data, which satisfies the desired target wind field. The fluctuating velocity data are given to the inlet boundary of the LES by developing an UDF script, which is implemented into the FLUENT. Then, two numerical models - the empty numerical wind tunnel model and the numerical wind tunnel model with spires and roughness elements are established based on the wind tunnel experiment to verify the present method. Finally, the turbulence generation approach presented in this paper is used to carry out a numerical simulation on the wind environment in an urban residential area in Lisbon. The computational results are compared with the wind tunnel experimental data, showing that the numerical results in the LES have a good agreement with the experimental results, and the simulated flow field with the inlet fluctuations can generate a reasonable turbulent wind field. It also shows that strong wind velocities and turbulent kinetic energy occur at the passageways, which may affect the comfort of people in the residential neighborhood, and the small wind velocities and vortexes appear at the leeward corners of buildings, which may affect the spreading of the pollutants.

• Journal of the Korean association of regional geographers
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• v.5 no.1
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• pp.137-150
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• 1999

Five land use change detection methods were applied to 1994 and 1997 Landsat Thematic Mapper (TM) images of Pook-Gu, Taegu city to determine the land-cover changes between the two dates. The two images were coregistred to UTM coordinates. A post-classification comparison method was the most commonly used quantitative method of change detection. A pre-classification comparison method was more effective method to change detection of land cover than a post-classification comparison method. Two indices were used to assess the accuracies of the studied methods. A image differencing method was found to be most accurate for detecting change verse no change among five land use change detection methods. The difference image of band 2 was found to be most accurate. The overall accuracy and Kappa index agreement of the difference image of band 2 were 0.810 and 0.447.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.2
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• pp.112-119
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• 2010

A Monte-Carlo simulation method is proposed which can evaluate the target failure/safety levels on any failure modes of harbor structures as a function of central safety factor. Unlike the calibration method based on the average safety level of conventional design criteria, the target failure/safety level can be directly evaluated by only using central safety factors of the harbor structures which have been designed by safety factor method during the past several decade years. Several mathematical relationships are represented to straightforwardly connect the conventional safety factor design method with reliability-based design method. Even though limited data have been used in applying Monte-Carlo simulation method to sliding failure mode of the vertical breakwaters, it is found that target reliability indices evaluated by the suggested method in this paper is satisfactorily agreement with new criteria of reliability index of Japan.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.66
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• pp.285-312
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• 2015

Export and import of food, agriculture, forestry, fishery products are suffering from low growth rate due to the European financial crisis, global recession, and Japan's 2012 export expansion following the aftermath of 2011 earthquake. Upon the signing and enactment of Free Trade Agreement with the U.S. and the EU, agriculture and fishery product have become the center of attention. Agriculture and fishery was reported to be 80million dollars, 1.46% of total national export, in 2012. Starting from2000, South Korea's government began its effort to expand agriculture and fishery export and as a result, export has steadily increased despite decreased consumption led by global recession. K-Sure has started an insurance program with the purpose of promoting SME business's export. It protects SME business against risk arising from credit, emergency, bad debt, and domestic price increase. This study aims to evaluate the service quality of K-Sure's insurance program via surveying SME businesses in the agriculture and fishery industry. Also this study will identify key service factors for SME businesses and explore ways to expand SME exports of agriculture and fishery by analyzing consumer satisfaction index. Results indicated service product quality factor, service communication quality factor, and social quality factor was key to improving consumer satisfaction for SME businesses in agriculture and fishery industry. Service product quality factor had a negative effect on consumer satisfaction in term of variety and results indicated that service communication quality factor's responsiveness element had minimal impact on consumer satisfaction. Conversely, all elements for social quality factor had positive effects on consumer satisfaction. Thus, leading to the conclusion that improvements in service product quality factor and service communication quality factor will indeed increase consumer satisfaction.

• Journal of Trauma and Injury
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• v.22 no.2
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• pp.134-141
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• 2009

Purpose: Patients with traumatic brain injury (TBI) were referred from other hospitals for further management. In addition, patients routinely underwent computed tomography examinations of the head (HCT) in the referral hospitals. The purpose of this study was to evaluate retrospectively the utility of routine HCT scans according to the severity of TBI. Methods: Patients with TBI referred to our hospital between December 2005 and July 2008 were included in this study. We investigated HCT findings, indications for repeat HCT examinations (routine versus a neurological change), and neurosurgical interventions. The head injury severity was divided into three categories according to the Glasgow Coma Scale (GCS) score, including mild, moderate, and severe TBI. The use of neurosurgical interventions between patients who underwent routine HCT scans and patients who underwent HCT scans for a neurological change were compared according to the severity of TBI. Results: A total of 81 patients met the entry criteria for this study. Among these patients, 67%(n=54) of the patients underwent HCT scans on a routine basis, whereas 33%(n=27) of the patients underwent HCT scans for a neurological change. A total of 21 patients showed signs of a worsening condition on the HCT scans. Neurosurgical intervention was required for 23(28.4%) patients. For patients who underwent routine HCT examinations, no patient with mild TBI underwent a neurosurgical intervention. However, one patient with moderate TBI and three(13%) patients with severe TBI underwent neurosurgical interventions. The kappa index, the level of agreement for HCT indications of intervention and referral reasons for intervention, was 0.65 for high hierarchy hospitals and 0.06 for low hierarchy hospitals. Conclusion: Routine serial HCT examinations in the referred hospitals would be useful for patients with severe head injury and for patients from low hierarchy hospitals where no emergency physicians or neurosurgeons are available.

• Fire Science and Engineering
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• v.27 no.5
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• pp.64-69
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• 2013

The autoignition temperatures (AITs) of solvent mixture was important index for the safe handling of flammable liquids which constitute the solvent mixtures. This study measured the AITs and ignition delay time for n-propanol and formic acid system by using ASTM E659 apparatus. The AITs of n-Propanol and Formic acid which constituted binary system were $435^{\circ}C$ and $498^{\circ}C$, respectively. The experimental AITs of n-propanol and formic acid system were a good agreement with the calculated AITs by the proposed equations with a few A.A.D. (average absolute deviation). And n- Propanol and formic acid system was shown the minimum autoignition temperature behavior (MAITB).