• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.1
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• pp.17-22
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• 2005

The movement of drifting ships on the sea is closely related to marine environmental forces such as waves, currents, winds, etc. To develop a prediction model for trajectories oi drifting ships, an experiment on the movement of drifting ships was carried out in the Southeastern Sea of Korea. Five types of ships including a lire raft and tour ships with G/T 10tons, G/T 2o tons, G/T 50 tons, and G/T 80 tons, were considered in the experiment. The G/T 50 ton class ship was used as a base ship for obtaining the currents, winds and heading angles of ship following the trajectory. The trajectory of each ship was measured by DGPS(Differential Global Positioning System) and collected using APRS(Automatic Position Reporting System) installed on the base ship. The error range in position fix of DGPS are approximately ±1 m. The drift speed of ship in the experiment was between 3％ to 5％ of wind speed and drift direction of ship was deflected by ±90° from wind direction. Also, the heading of drifting ship was normal to wind direction.

• Journal of the Korean Data and Information Science Society
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• v.20 no.5
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• pp.845-855
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• 2009

The purpose of this study was to examine the category function, the item structure, and the model-data fit of the Copenhagen neck functional disability scale (CNFDS) with neck pain subjects using Rasch rating scale analysis. The data was obtained from the assessments of 71 college students with neck pain. The 'concentration' item showed misfit and fourteen items were founds to be fits for self-reporting of disability due to neck pain. The most difficult item of the remaining 14 items was 'help' and the easiest item was 'social contact'. The subjects and items reliability of separation reliability were 0.85 and 0.97. The CNFDS for self-reporting of disability due to mild neck pain has been proved valid and reliable. This study is suggested that individuals with mild neck pain may be used the modified CNFDS that were not included 'concentration' item and were adjusted the 2 response levels.

• Journal of Environmental Health Sciences
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• v.40 no.5
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• pp.385-396
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• 2014

Objectives: By conducting a meta-analysis of cohort studies reporting standardized mortality ratios (SMRs) for workers exposed to trichloroethylene, we attempted to adjust for healthy hired effect by applying the same methods as described in a recent report from the Agricultural Health Study. Methods: Among all cohort studies that evaluated the association between all cancer, non-Hodgkin's lymphoma (NHL), kidney cancer, liver cancer and occupational exposure to trichloroethylene, a total of 10 studies reporting SMR values were selected. A random-effects model was used to estimate the summary SMRs or rSMRs and 95% confidence intervals. Relative SMR ($rSMR=SMR_x/SMR_{not\;x}$) was calculated comparing observed and expected counts for all cancer, NHL, kidney cancer, and liver cancer with an independent referent set of values consisting of the observed and expected counts for other causes. Results: The SMR values for all causes ranged from 0.68 to 1.03, suggesting moderate to weak healthy worker effect for the selected studies. When the healthy worker hire effect was taken into account, the summarized risk became statistically significant; the summary SMR of all cancer was 0.95 (0.91-1.00) and the summary rSMR of all cancer was 1.10 (1.04-1.15). The summary SMR of NHL was 1.04 (0.93-1.14) and the summary rSMR of NHL was 1.23 (1.04-1.46). The summary SMR of kidney cancer was 1.08 (0.88-1.33) and the summary rSMR of kidney cancer was 1.23 (1.02-1.49). The summary SMR of liver cancer was 0.88 (0.78-0.99), and the summary rSMR of liver cancer was 0.95 (0.84-1.07). Conclusion: The rSMR method is useful to determine summary risk adjusted for healthy worker effect through meta-analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.190-196
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• 2020

FRACAS(Failure Reporting, Analysis and Corrective Action System) has been applied in various industries to improve the reliability of the systems. FRACAS is effective in improving reliability by repeating failure analysis, proper corrective action, and result verification for identified failures. However, FRACAS has many limitations in terms of process, data collection and management to be integrated into the existing development environment. In the domestic defense industry, studies on the development of FRACAS system and process improvement have been conducted to solve the difficulties of applying FRACAS, but most of them are concentrated in the operation/maintenance phase. Since FRACAS should be conducted in consideration of TLCSM(Total Life Cycle System Management), it is necessary to study the reference architecture so that FRACAS can be applied from the early design phase. In this paper, we studied the TLCSM-based integrated architecture considering the system life cycle phases, FRACAS closed-loop process, and FRACAS essentials in order to effectively apply FRACAS throughout the life cycle of defense systems. The proposed architecture was used as a reference model for FRACAS in a shipboard combat system.

• The Journal of Korean Academic Society of Nursing Education
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• v.21 no.2
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• pp.276-284
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• 2015

Purpose: This study was conducted to investigate the factors that affect subjective well-being in nursing students. Methods: A total of 236 nursing students participated in the study. Data was collected from November through December 2013 using a self-reporting questionnaire that surveyed the level of gratitude, interpersonal relationship ability, subjective happiness, and life satisfaction. Data was analyzed by descriptive analysis, t-test, ANOVA, Pearson correlation coefficients and multiple regression with the SPSS/WIN 18.0 program. Results: Subjective happiness positively correlated with gratitude (r=.41, p<.001) and interpersonal relationship ability (r=.55, p<.001). Life satisfaction positively correlated with gratitude (r=.53, p<.001) and interpersonal relationship ability (r=.37, p<.001). Significant predictors of subjective happiness included gratitude (${\beta}=.38$, p<.001), interpersonal relationship ability (${\beta}=.28$, p<.001) and major satisfaction (${\beta}=.17$, p=.002). The regression model explained 39.3% of subjective happiness. Significant predictors of life satisfaction included gratitude (${\beta}=.42$, p<.001), academic achievement (${\beta}=.15$, p=.006), interpersonal relationship ability (${\beta}=.16$, p=.008) and major satisfaction (${\beta}=.12$, p=.035). The regression model explained 35.3% of life satisfaction. Conclusion: To improve subjective well-being among nursing students, nurse educators should develop educational intervention programs to promote gratitude and interpersonal relationships.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.4
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• pp.60-66
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• 2016

Compound logistics is a service aimed to enhance logistics efficiency by supporting that shippers and consigners jointly use logistics facilities. Many of these services have taken place both domestically and internationally, but the joint logistics services for e-commerce have not been spread yet, since the number of the parcels that the consigners transact business is usually small. As one of meaningful ways to improve utilization of compound logistics, we propose a brokerage service for shipper and consigners based on the hybrid recommendation system using very well-known classification and clustering methods. The existing recommendation system has drawn a relatively low satisfaction as it brought about one-to-one matches between consignors and logistics vendors in that such matching constrains choice range of the users to one-to-one matching each other. However, the implemented hybrid recommendation system based brokerage agent service system can provide multiple choice options to mutual users with descending ranks, which is a result of the recommendation considering transaction preferences of the users. In addition, we applied feature selection methods in order to avoid inducing a meaningless large size recommendation model and reduce a simple model. Finally, we implemented the hybrid recommendation system based brokerage agent service system that shippers and consigners can join, which is the system having capability previously described functions such as feature selection and recommendation. As a result, it turns out that the proposed hybrid recommendation based brokerage service system showed the enhanced efficiency with respect to logistics management, compared to the existing one by reporting two round simulation results.

• Journal of the Korean Institute of Gas
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• v.22 no.5
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• pp.107-113
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• 2018

While accident data are used to show alertness to accidents or to review similar cases, the analysis of nature of accident data its association with surrounding environment is very insufficient. Therefore, it is very necessary to demonstrate the possibility of an accident for a particular region by developing analysis techniques with the related accident data. The purpose of this study is to develop an analysis model and implement a system that produces regional accident probability based on historical weather information data and accident and reporting data. In other words, the system is designed and developed to create models by k-NN and decision tree algorithms with optional user-environment variables based on the probability between weather and accidents about many particular region of Korea. In the future, the models developed in this study are intended to be used to analyze and calculate the risk of a more narrow area.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.4
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• pp.203-212
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• 2002

This study was conducted to remove the urban heat island effects embedded in the interpolated surfaces of daily minimum temperature in the Korean Peninsula. Fifty six standard weather stations are usually used to generate the gridded temperature surface in South Korea. Since most of the weather stations are located in heavily populated and urbanized areas, the observed minimum temperature data are contaminated with the so-called urban heat island effect. Without an appropriate correction, temperature estimates over rural area or forests might deviate significantly from the actual values. We simulated the spatial pattern of population distribution within any single population reporting district (city or country) by allocating the reported population to the "urban" pixels of a land cover map with a 30 by 30 m spacing. By using this "digital population model" (DPM), we can simulate the horizontal diffusion of urban effect, which is not possible with the spatially discontinuous nature of the population statistics fer each city or county. The temperature estimation error from the existing interpolation scheme, which considers both the distance and the altitude effects, was regressed to the DPMs smoothed at 5 different scales, i.e., the radial extent of 0.5, 1.5, 2.5, 3.5 and 5.0 km. Optimum regression models were used in conjunction with the distance-altitude interpolation to predict monthly normals of daily minimum temperature in South Korea far 1971-2000 period. Cross validation showed around 50% reduction in terms of RMSE and MAE over all months compared with those by the conventional method.conventional method.

• Journal of Internet Computing and Services
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• v.5 no.4
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• pp.11-22
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• 2004

Works that improve the process and notify the improved process, the product and the change of tasks to all users are essential in achieving project. Existent project management tools support the definition and the change of project activities, and configuration management tools support version check, workspace management. build management. etc. It costs too much to buy each tool. as well as, it is burdensome to learn usage for various tools. Therefore the web-based integrated tool is proposed to manage the process and artifacts at a time in this paper. The proposed tool defines component based development process model. and achieves recording of process progression, processing the request of change, reporting the progression of each task, product registering and change, version recording, artifact or form search, etc. using ebXML. Furthermore, the stakeholders get the systematic management and standardization by sharing information that are necessary in process achievement and configuration management in distributed environment using the integrated management tool.

• Journal of Forest and Environmental Science
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• v.30 no.2
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• pp.233-242
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• 2014

Estimating above-ground biomass is important in establishing an applicable methodology of Measurement, Reporting and Verification (MRV) System for Reducing Emissions from Deforestation and Forest Degradation-Plus (REDD+). We developed an estimation model of diameter at breast height (DBH) from IKONOS-2 image that led to above-ground biomass estimation (AGB). The IKONOS image was preprocessed with dark object subtraction and topographic effect correction prior to watershed segmentation for tree crown delineation. Compared to the field observation, the overall segmentation accuracy was 64%. Crown detection percent had a strong negative correlation to tree density. In addition, satellite-based crown area had the highest correlation with the field measured DBH. We then developed the DBH allometric model that explained 74% of the data variance. In average, the estimated DBH was very similar to the measured DBH as well as for AGB. Overall, this method can potentially be applied to estimate AGB over a relatively large and remote tropical forest in Northern Borneo.