• Wind and Structures
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• v.2 no.3
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• pp.133-150
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• 1999

Significant costs to the public and private sectors due to recent extreme wind events have motivated the need for systematic post-hurricane damage data collection and analysis. Current post disaster data are collected by many different interested groups such as government agencies, voluntary disaster relief agencies, representatives of media companies, academicians and companies in the private sector. Each group has an interest in a particular type of data. However, members of each group collect data using different techniques. This disparity in data is not conducive to quantifying damage data and, therefore, inhibits the statistical and spatial description of damage and comparisons of damage among different extreme wind events. The data collection does not allow comparisons of data or results of analyses within a group and also prohibits comparison of damage data and information among different groups. Typically, analyses of data from a given event lead to different conclusion depending upon the definition of damage used by individual investigators and the type of data collected making it difficult for members of groups to compare the results of their analyses with a common language and basis. A formal method of data collection and analysis-within any single group-would allow comparisons to be made among different individuals, hazardous events and eventually among different groups, thus facilitating the management and reduction of damage due to future disaster. This research introduces a definition of damage to single family dwellings, and a common method of data collection and analysis suited for groups interested in regional characterization of damage. The current state-of-data is presented and a method for data collection is recommended based on these existing data collection methods. A fixed-scale damage index is proposed to consider the damage to a dwelling's feature. Finally, the damage index is applied to three dwellings damaged by Hurricane Iniki (1992). The damage index reflects the reduced functionality of a structure as a single family detached dwelling and provides a means to evaluate regional damage due to a single event or to compare damage due to events of different severity. Evaluation of the damage index and the data available support recommendation for future data collection efforts.

• Structural Engineering and Mechanics
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• v.24 no.6
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• pp.709-725
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• 2006

In this paper the buckling and post-buckling behavior of slender bars under self-weight are studied. In order to study the post-buckling behavior of the bar, a geometrically exact formulation for the non-linear analysis of uni-directional structural elements is presented, considering arbitrary load distribution and boundary conditions. From this formulation one obtains a set of first-order coupled nonlinear equations which, together with the boundary conditions at the bar ends, form a two-point boundary value problem. This problem is solved by the simultaneous use of the Runge-Kutta integration scheme and the Newton-Raphson method. By virtue of a continuation algorithm, accurate solutions can be obtained for a variety of stability problems exhibiting either limit point or bifurcational-type buckling. Using this formulation, a detailed parametric analysis is conducted in order to study the buckling and post-buckling behavior of slender bars under self-weight, including the influence of boundary conditions on the stability and large deflection behavior of the bar. In order to evaluate the quality and accuracy of the results, an experimental analysis was conducted considering a clamped-free thin-walled metal bar. As this kind of structure presents a high index of slenderness, its answers could be affected by the introduction of conventional sensors. In this paper, an experimental methodology was developed, allowing the measurement of static or dynamic displacements without making contact with the structure, using digital image processing techniques. The proposed experimental procedure can be used to a wide class of problems involving large deflections and deformations. The experimental buckling and post-buckling behavior compared favorably with the theoretical and numerical results.

• The Journal of Information Systems
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• v.29 no.2
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• pp.287-306
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• 2020

Purpose Youth unemployment is a social problem that continues to emerge in Korea. In this study, we create a model that predicts the employment of college graduates using decision tree, random forest and artificial neural network among machine learning techniques and compare the performance between each model through prediction results. Design/methodology/approach In this study, the data processing was performed, including the acquisition of the college graduates' vocational path survey data first, then the selection of independent variables and setting up dependent variables. We use R to create decision tree, random forest, and artificial neural network models and predicted whether college graduates were employed through each model. And at the end, the performance of each model was compared and evaluated. Findings The results showed that the random forest model had the highest performance, and the artificial neural network model had a narrow difference in performance than the decision tree model. In the decision-making tree model, key nodes were selected as to whether they receive economic support from their families, major affiliates, the route of obtaining information for jobs at universities, the importance of working income when choosing jobs and the location of graduation universities. Identifying the importance of variables in the random forest model, whether they receive economic support from their families as important variables, majors, the route to obtaining job information, the degree of irritating feelings for a month, and the location of the graduating university were selected.

• Journal of Digital Convergence
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• v.18 no.7
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• pp.299-306
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• 2020

The purpose of this study is to find out specific measures that can help the management strategy of patient-centered medical institutions by conducting research on patient experience surveys of convergence outpatient medical services using data mining techniques according to changes in patient-centered medical culture. Using the raw data of the 2018 Medical Service Experience Survey, 8,843 people over the age of 15 who had patient experience in outpatient medical services were analyzed. Decision tree analysis was performed. The determinants of satisfaction with outpatient medical services patient experience were the doctor's area and patient's rights protection area, and the determinants of intention to recommend outpatient medical services were the doctor's area and facilities comfort. Women evaluated the experience positively in overall satisfaction as compared to men, and those over the age of 60 positively evaluated the overall satisfaction and intention to recommend. It is significant that the outpatient experience decision-making model is presented, and that the doctor's area, patient's rights protection area, and facility comfort are important factors. Long-term research on the 'Medical Service Experience Survey' is needed, and research on the inpatient medical service experience is needed.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.5
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• pp.639-654
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• 2010

This study attempted to research the local food of various regions at a personal level by discovering how food has developed das part of a region's culture base. Discovery of the characteristic story behind the making of a region's characteristic food as local delicacies can inspire self-esteem in the culture, and enhance the real-life image as appropriate to a region, and thereby be made a part of local tourism and thus contributing to the local economy. For this reason, the native foods of the region of Chungcheongnam-do were researched in terms of the cultural sensibilities that inform the unique history of that region. The study was designed so as to aid in understanding food's characteristic value in Chungcheongnam-do and to give a historical representation of Chungcheongnam-do's image by means of storytelling techniques; thus, the local food's character can be presented alongside a story that appeals to the five senses. For this purpose, Chungcheongnam-do's representative native rice table was cast as the 'Hyunchoong rice meal table' - after the figure of admiral Yi Sun Shin of Asan area region, a representative image of Chungcheongnam-do - and 'Choosa rice meal table', after the figure of 'Choosa' Kim Jeong Hee of Yesan region, of which various literary works form a representative image of Chungcheongnam-do. 'Hyunchoong rice meal table' was composed of a health food centered menu which could supply sufficient nutrition as a food ration in times of war or winter shortage, thus providing an image of nutrition and power as appropriate to these situations. Also, to assess the health effectiveness of each rice table, the functionality of the ingredients were investigated as reported in 'Sik-ryo-chan-yo : a dietary treatment' which was published by Soon-Ui Cheon in the Chosun era and by which the foods of the early Chosun era won recognition as being both healthy profitable.

• Journal of the Korea Society for Simulation
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• v.27 no.3
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• pp.37-44
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• 2018

In applying modeling and simulation (M&S) techniques to analyze complex discrete event dynamic systems, conventionally users had to use different simulation environments depending on the user-level. To solve the inconvenience, this paper proposes an integrated development environment for M&S depending on user-level and a formalized interface to manage the model in the development environment efficiently. The interface consists of an extended DEVS formalism and model making rules. The development environment is divided into a modeling environment and a simulation environment. In the modeling environment, three modeling methods are provided for each level of the users. Users inputs several parameters to the model generated as a result of the modeling process, and experiments in various cases by using the simulation environment. The case study shows the implementation of the proposed M&S environment, and using the implemented environment, it shows the M&S process of the complex defense combat system.

• Journal of Service Research and Studies
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• v.3 no.1
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• pp.9-16
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• 2013

Data analysis is the universal classification techniques, which requires a lot of effort. It can be easily analyzed to understand the results. Decision tree which is developed by Breiman can be the most representative methods. There are two core contents in decision tree. One of the core content is to divide dimensional space of the independent variables repeatedly, Another is pruning using the data for evaluation. In classification problem, the response variables are categorical variables. It should be repeatedly splitting the dimension of the variable space into a multidimensional rectangular non overlapping share. Where the continuous variables, binary, or a scale of sequences, etc. varies. In this paper, we obtain the coefficients of precision, reproducibility and accuracy of the classification tree to classify and evaluate the performance of the new cases, and through experiments to evaluate.

• Water for future
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• v.29 no.3
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• pp.197-205
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• 1996

Flow carrying capacity of water distribution systems is getting reduced by deterioration of pipes in the systems. The objective of this study is to develop a managerial decision-making model for the rehabilitation of water distribution systems with a minimum cost. The decisions made by the model also satisfy the requirements for the discharge and pressure at demanding nodes in the system. The replacement cost, pipe break repair cost, and pumping cost are considered in the economic evaluation of the decision along with the break ratio and interest ratio to determine the optimal replacement time for each pipe. Then, the hydraulic integrity of the water distribution system is checked for the decision by a pipe network simulator, KYPIPE, if the discharge and pressure requirements, the decision made for the optimal replacement time is revised until the requirements are satisfied. The model is applied to an existing water distribution system, the Metropolita Water Supply Project (1st Phase). The result shows that the decisions for the replacement time determined by the economix analysis are accepted as optimal and the hydraulic integrity of the system is in good condition.

• Journal of Korea Society of Industrial Information Systems
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• v.20 no.4
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• pp.1-9
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• 2015

This paper proposes CAC method that is more efficient for RRM using game theory combined with Multiple Attribute Decision Making(MADM). Because users request services with different Quality of Service(QoS), the network preference values to alternative networks for each service are calculated by MADM methods such as Grey Relational Analysis(GRA), Simple Additive Weighting(SAW) and Technique for Order Preference by Similarity to Ideal Solution(TOPSIS). According to a utility function representing preference value, non-cooperative game is played, and then network provider select the requested service that provide maximum payoff. The appropriate service is selected through Nash Equilibrium that is the solution of game and the game is played repeated. We analyze two overlaid networks among four Wireless LAN(WLAN) systems with different properties. Simulation results show that proposed MADM techniques have same outcomes for every game round.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.6
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• pp.561-569
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• 2008

Currently, satellite image, aerial image and airborne laser scanning data are mostly used to build 3D image models. However, we are in need of quality 3D image models as current models cannot express topographic and features most elaborately and realistically. When making 3D image models, the model is first built and textures from terrestrial photos are applied to add realistic features to the model. This study analyzed techniques to use photogrammetry and laser scanning data to create a 3D image models with topography, building and statue that emphasize spatial accuracy, delicate depiction and photo-realistic imaging. 3D image models with spatial accuracy and photographic texture were built to be served via 3D image map services systems on the internet. The 3D image models can be used for various purposes, such as daylight and view right analysis, landscape analysis, facility management system.