• Journal of Navigation and Port Research
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• v.32 no.8
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• pp.569-576
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• 2008

By the development of international trade in last decades, Korean International Trade has been grown rapidly and Korean Port and Port facilities have been improved stimultaneously: finally volume of the marine traffic increased rapidly. Presently, 15 VTS centers have serving in Korean waters and since the introduction of the first VIS Center in Korea there is no quantitative analysis to find workload of VIS operator. After that Port-MIS and De-brief data have been gathered for 7 days and inbound-outbound vessels time-g/t table prepared and traffic volume examined for each V1S center. Hence $L^2$ conversion traffic volume and dangerous vessel ratio obtained Later on conversion controlled number obtained by denoting ratio 1.0 to directly controlled vessels by VTSO and denoting ratio 0.3 to indirectly controlled vessels by VTSO. Traffic volume, large vessel ratio, dangerous vessel ratio, dimension of VTS controlled area, marine accident occurrence frequency and communication volume of comm. log can be counted as a factor which influence to workload of VTSO. All those factors have been examined and analyzed. Finally, ship's size and dangerous vessel ratio have been chosen to derive the Number of composite conversion control for workload formula.

• Korean Journal of Construction Engineering and Management
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• v.19 no.6
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• pp.46-54
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• 2018

In the 21st century, the Earth has continued its efforts to reduce carbon emissions to overcome the crisis caused by climate change. The construction industry, which is a representative industry that produces large amounts of the environmental load during construction, should actively reduce the amount of the environmental load. From the planning stage of the construction facility, it is necessary to consider the environmental load such as route selection and structure type selection to reduce the environmental load. However, the environmental load can be estimated based on the input resource amount. However, in the planning stage, it is difficult to accurately calculate the environmental load due to lack of information on the construction amount. The purpose of this study is to select the environmental load factors for IPC girder bridges to be used in the environmental load estimation model in the planning stage. Specific information related to the environmental load was selected from a list of information available in the planning stage, reflecting the Life Cycle Assessment(LCA), correlation, principal components analysis and expert opinion. The list of selected planning stage information is 10 such as span length and bridge extension, and it is expected to be used as a basic data for the future development of environmental load estimation model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.218-225
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• 2016

Recently, Korea has undergone rapid social and economic development, and with that came various changes in living habits and disease patterns; the nation, accordingly, has been alerted to the associated risks of chronic ailments. As risk factors of metabolic syndrome commonly include causal factors of chronic diseases, prevention is important. The prevalence of metabolic syndrome in Korean adults is 22.4%, which comprises a large portion of the whole disease (Korean National Health and Nutrition Examination Survey, 2013). This study aims to examine the elements of healthy living practices by analyzing the risk factors of metabolic syndrome and health behaviors, and provide basic materials to contribute to the activation of health promotion. Among 12,481 subjects of the source data from the 2014 community health survey, which was performed on adults aged 19 and over in Jeonlabuk-do, 12,185 people were analyzed in this study using SPSS 23.0. There were significant differences with respect to sex, smoking status, age, education level, and number of days of physical activity among the results of the difference of the risk factors of the metabolic syndrome according to the characteristics of the health behavior of the subjects. Of the risk factors for metabolic syndrome, this study emphasized the necessity of strategies to promote health programs regarding the management of drinking, smoking, physical activities, depression, subjective health condition and quality of life to the group of those with dyslipidemia, hypertension, and diabetes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.35-46
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• 2017

This study analyzed the role of innovation intermediaries on the performance of technology-based firms in Korea. Technology-based firms are important to the economy because they contribute to regional economic development and national competitiveness. In Korea, various types of intermediaries, such as Techno-parks and incubators have been established to foster technology-based firms. Researchers analyzed various factors influencing the performance of technology-based firms. On the other hand, there have been few studies on the relationship between the innovation intermediaries and the performance of technology-based firms in Korea. This study identified the firms' capabilities, institutional and environmental factors in the light of the literature. A total of 2,313 technology-based firms in Techno-parks, business incubator of public institutes and universities were surveyed. Of these, 110 respondents were used for empirical analysis. OLS techniques were applied to analyze the data. The empirical results showed that the marketing competence, R&D capacity, which is a firms' innovation capacity, have a positive effect on the performance. The support of intermediaries positively affects the performance of technology-based firms. The economic aspects of regional innovation infrastructure, and cooperation with the customer has a positive effect on the performance of technology-based firms.

• YAKHAK HOEJI
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• v.59 no.3
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• pp.98-106
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• 2015

Analytical method for related substances can be categorized into two methods depending on the necessity of reference standard (RS). The analytical method of related substances with RS is fast and accurate, but it's very expensive and technically difficult to synthesize RS due to their complicated structure. Another method is using relative retention time (RRT) and relative response factor (RRF) which are already validated with RS. Validation of this method is not easy and time consuming, but once it has been developed, it can save cost and time. In this study, we developed the analytical method for related substances of fenofibrate using RRT and RRF. We validated the method by evaluating specificity, linearity, accuracy and precision according to the "Manual for Guideline Application for Validation of Analytical Procedures" of MFDS. Also, we calculated RRT and RRF between fenofibrate and fenofibrate related substances. The results of this study showed high specificity for fenofibrate and fenofibrate related substances. Correlation coefficient(r) of all substances were more than 0.99, and the recovery of fenofibrate, fenofibrate related substance I, II and III were 99.44%, 100.84%, 99.14% and 101.58%, respectively. Precision of fenofibrate and its related substances were ranged between RSD 0.29% and 0.93%. Quantification limits of fenofibrate, fenofibrate related substance I, II and III were determined to be $0.03{\mu}g/ml$, $0.05{\mu}g/ml$, $0.04{\mu}g/ml$ and $0.02{\mu}g/ml$, respectively by confirming signal to noise ratio of each chromatogram. The RRT for fenofibrate related substance I, II and III were determined to be 0.35, 0.41 and 1.34, respectively. Also, the RRF for fenofibrate related substance I, II and III were determined to be 1.28, 0.98 and 0.79, respectively. The developed method was applied to determine contents for fenofibrate related substances in commercial fenofibrate (active pharmaceutical ingredient). As a result, developed analytical methods of related substances will be used for revising the monograph of fenofibrate in Korean Pharmacopoeia revision and contribute quality control of drugs by improving cost and time consuming problem of RS.

• International Journal of Highway Engineering
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• v.16 no.3
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• pp.43-50
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• 2014

PURPOSES : The dynamic modulus can be determined by applying the various theories from the Impact Resonance Testing(IRT) Method. The objective of this paper is to determine the best theory to produce the dynamic modulus that has the lowest error as the dynamic modulus data obtained from these theories(Complex Wave equation Resonance Method related to either the transmissibility loss or not, Dynamic Stiffness Resonance Method) compared to the results for dynamic modulus determined by using the Universal Testing Machine. The ultimate object is to develop the predictive model for the dynamic modulus of a Linear Visco-Elastic specimen by using the Complex Wave equation Resonance Method(CWRM) came up for an existing study(S. O. Oyadiji; 1985) and the Optimization. METHODS : At the destructive test which uses the Universal Testing Machine, the dynamic modulus results along with the frequency can be used for determining the sigmoidal master curve function related to the reduced frequency by applying Time-Temperature Superposition Principle. RESULTS : The constant to be solved from Eq. (11) is a value of 14.13. The reduced dynamic modulus obtained from the IRT considering the loss factor related to the impact transmissibility has RMSE of 367.7MPa, MPE of 3.7%. When the predictive dynamic modulus model was applied to determine the master curve, the predictive model has RMSE of 583.5MPa, MPE of 3.5% compared to the destructive test results for the dynamic modulus. CONCLUSIONS : Because we considered that the results obtained from the destructive test had the most highest source credibility in this study, the dynamic modulus data obtained respectively from DSRM, CWRM were compared to the results obtained from the destructive test by using th IRT. At the result, the reduced dynamic modulus derived from DSRM has the most lowest error.

• Journal of the Korea Society for Simulation
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• v.25 no.2
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• pp.21-29
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• 2016

Indoor location system has been used Wi-Fi to get a location. After the development of BLE(Bluetooth Low Energy), the interest in the method of a indoor positioning had been move on. It has more advantages than using Wi-Fi. Easy installation, low power consumption, low signal interference and changeable setting(Advertising interval, tx power, etc.). These things can improve efficiency or accuracy in a indoor positioning system. For this reason, recent indoor positioning system uses BLE rather than Wi-Fi. Accordingly, error factors of BLE beacon based indoor positioning should be studying for high accuracy of indoor positioning. In this research, set up few experiment scenarios and keep a close watch on how technological, environmental factor is affecting positioning accuracy. When a application uses largest signal strength to get the indoor location, the mean error of experimental results was decreased compare to using received signal strength in real-time. The result was same when the application applied average and standard deviation to get the indoor location. Changing advertising interval had an effect on the mean error of indoor positioning. Short advertising interval makes the lower mean error than large advertising interval.

• Journal of the Society of Naval Architects of Korea
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• v.54 no.6
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• pp.476-484
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• 2017

The purpose of this paper is to verify the structural integrity of a region with numerous penetration-holes in offshore structures such as semi-submersible rig and FPSO. In order to effectively check the yielding and buckling strength of plate members with penetration-holes, a screening analysis program was developed with the FE analysis tool to generate fine meshed model using the theoretical and analysis methods. When a hole is appeared in the plate structure members, the flow of stress is altered such that concentrations of stress form near the hole. Stress concentrations are of concern during both preliminary and detail design and need to be addressed from the perspectives of strength. To configure the geometrical shape, very fine meshed FE analysis is needed as the most accurate method. However, this method is practically impossible to apply for the strength verifications for all perforated plates. In this paper, screening analysis method was introduced to reduce analysis tasks prior to detailed FE analysis. This method is applied to not only the peak stress calculation combined stress concentration factor with nominal stress but also nominal equivalent stress calculation considering cutout effects. The areas investigated by very fine meshed analysis were to be chosen through screening analysis without any reinforcements for penetration-holes. If screening analysis results did not satisfy the acceptance criteria, direct FE analysis method as the 2nd step approach were applied with one of the coarse meshed model considering hole or with the very fine meshed model considering the hole shape and size. In order to effectively perform the local fine meshed analysis, automatic model generating program was developed based on the MSC/PATRAN which is pre-post FE analysis program. Buckling strength was also evaluated by Common Structure Rule (CSR) adopted by IACS as the stress obtained from very fine meshed FE analysis. Due to development of the screening analysis program and automatic FE modeling program, it was able to reduce the design periods and structural analysis costs.

• Journal of Chest Surgery
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• v.31 no.12
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• pp.1159-1164
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• 1998

Background: Although operative outcome is progressing due to the development of operative techniques and myocardial protection, some patients face an increased morbidity and mortality. Therefore, it has become increasingly important to predict the operative morbidity and mortality. Material and Method: This retrospective study reports the results of risk factor analysis of morbidity and mortality of 137 consecutive patients who were underwent coronary artery bypass graft surgery(CABG). Preoperative variables were age, sex, preoperative myocardial infarction, operative priority, left ventricular ejection fraction, obesity and triple vessel disease. Postoperative morbidities were arrhythmia, wound infection, cerebral infarction, prolonged postoperative hospitalization, pneumonia, acute renal failure, prolonged use of ventilator and operative death. Result: The mean age of total patients was 56.7 years, from 27 to 74. The overall mortality was 6.6%(9 of 137) with the mortality of 3.9%(5 of 128) for elective operation, and 44.4%(4 of 9) for emergent or urgent cases. The morbidity of patients over 65 years was stastistically higher than that of under 65 years. Sex distribution showed no difference in morbidity, however operative mortality rate was slightly higher in women (5/41, 12.19%) than in men(4/96, 4.17%). Morbidity of emergent or urgent operation was 100%, much higher than that of the elective operation. Mortality of the patients whose left ventricular ejection fraction was under 50% was higher than that of those over 50%. Conclusion: We concluded that the risk factors of morbidity after CABG were old age above 65 years and emergent or urgent operation, and that risk factors of mortality were low left venticular ejection fraction under 50% and emergent or urgent operation.

• Journal of Korea Water Resources Association
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• v.47 no.4
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• pp.357-370
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• 2014

This study aims to develop a rainfall field tracking method for depth-area-duration (DAD) analysis and assess whether the proposed tracking methods are able to properly estimate the maximum average areal rainfall (MAAR) within the study area during a rainfall period. We proposed three different rainfall field tracking algorithms (Box-tracking, Point-tracking, Advanced point-tracking) and then applied them to the virtual rainfall field with 1hr duration and also compared DAD curves of each method. In addition, we applied the three tracking methods and a traditional GIS-based tool to the typhoon 'Nari' rainfall event of the Yongdam-Dam watershed and then assess applicability of the proposed methods for DAD analysis. The results showed that Box-tracking was much faster than the other two tracking methods in terms of searching for the MAAR but it was impossible to describe rainfall spatial pattern during its tracking processes. On the other hand, both Point-tracking and Advanced point-tracking provided the MAAR by considering the spatial distribution of rainfall fields. In particular, Advanced point-tracking estimated the MAAR more accurately than Point-tracking in the virtual rainfall field, which has two rainfall centers with similar depths. The proposed automatic rainfall field tracking methods can be used as effective tools to analyze DAD relationship and also calculate areal reduction factor.