• Computers and Concrete
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• v.8 no.2
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• pp.193-206
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• 2011

The use of Carbon Fiber Reinforced Polymers (CFRP) to strengthen reinforced concrete beams under bending and shear has gained rapid growth in recent years. The performance of shear strengthened beams with externally bonded CFRP laminate or fabric strips is raising many concerns when the beam is loaded under cyclic loading. Such concerns warrant experimental, analytical and numerical investigation of such beams under cyclic loading. To date, limited investigations have been carried out to address this concern. This paper presents a numerical investigation by developing a nonlinear finite element (FE) model to study the response of a cantilever reinforced concrete T-beam strengthened in shear with side bonded CFRP fabric strips and subjected to cyclic loading. A detailed 3D nonlinear finite element model that takes into account the orthotropic nature of the polymer's fibers is developed. In order to simulate the bond between the CFRP sheets and concrete, a layer having the material properties of the adhesive epoxy resin is introduced in the model as an interface between the CFRP sheets and concrete surface. Appropriate numerical modeling strategies were used and the response envelope and the load-displacement hysteresis loops of the FE model were compared with the experimental response at all stages of the cyclic loading. It is observed that the responses of the FE beam model are in good agreement with those of the experimental test. A parametric study was conducted using the validated FE model to investigate the effect of spacing between CFRP sheets, number of CFRP layers, and fiber orientation on the overall performance of the T-beam. It is concluded that successful FE modeling provides a practical and economical tool to investigate the behavior of such strengthened beams when subjected to cyclic loading.

• Journal of the Korean GEO-environmental Society
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• v.11 no.7
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• pp.45-49
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• 2010

We have developed and demonstrated the use of a new kinetic method as an analytical tool for the measurement of $HO_2{\cdot}/O_2{\cdot}^-$. This new method is based on the reduction of $Fe^{3+}$-Ethylene Diamine Tetra Acetate, EDTA) into $Fe^{2+}$-EDTA by $HO_2{\cdot}/O_2{\cdot}^-$ and the well-known Fenton-like reaction of $H_2O_2$ and $Fe^{2+}$-EDTA to yield the hydroxyl radicals ($OH{\cdot}$). Since this method for $HO_2{\cdot}/O_2{\cdot}^-$ shows high sensitivity and allows a simple calibration system, it can contribute significantly to understanding the basic functions of $HO_2{\cdot}/O_2{\cdot}^-$ in advanced oxidation processes for water treatment. Moreover, the present technique has the advantage of using inexpensive and easily available nonenzymatic reagents and of being insensitive to the moderate concentration of possible interferences often found in aqueous phase.

• Information Systems Review
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• v.13 no.3
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• pp.1-14
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• 2011

In recent years, SNS (Social Network Service) has spread globally and general corporate' utilization of SNS is gradually increasing. Accordingly, the scope of utilizing SNS is expanding not only as a simple publicity of products and services but also as a communication tool among the company members, the customer service and the product development, etc. This study is examining the related cases classified by the premier activities and the supportive activities of the private companies' viewpoints of utilizing the SNS. Based on this study results, we are proposing the strategic considerations for the private companies' SNS adoption by synthesizing the results of the analytical researches of the SNS cases that support the companies' value chain and the considerations of companies' utilization of the SNS that are proposed by the various private companies' research laboratories.

• Journal of the Ergonomics Society of Korea
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• v.34 no.6
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• pp.549-561
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• 2015

Objective: The purpose of this study was to investigate the job stress factors of mobile communication network construction workers using survey based on 'Job stress factors evaluation tool for Koreans' that was developed by KOSHA in 2003. Background: Due to the rapid growth of penetration rate of smartphone, the necessity of LTE service changing from 3G network was brought up. The demand of LTE network construction in a short period of time leads to the aggravation of the job stress of mobile communication network construction workers. Method: Two hundred and fifty workers who were in the mobile communication network industry participated in this study, and among them 206 responses were analyzed for this study due to the unreliability and insincerity of responses. The eight job stress factors which are physical environment, job demand, job autonomy, relation conflict, job instability, organizational system, inadequate compensation, workplace culture were analyzed. Results: The job stress factors of mobile communication network construction workers were compared to those of other industry workers, and other work related characteristics were analyzed. The results showed that the stress level of a physical environment and job requirement were relatively higher than those of manufacturing industry workers, meaning that mobile communication network construction workers have rough working conditions and increased amount of work due to the demand of LTE network construction. The stress level of physical environment for outdoor job workers was relatively higher than that of indoor job workers. With the analytical result for level of job satisfaction, significant difference was observed (p <0.05) with every factor, and the job stress was found the highest with those not satisfied with every factor Conclusion: From the results of this study, the work loss due to the job stress could be prevented, and accurate stress factors could be removed at the workplace. Application: The results of this study may not represent the whole mobile network construction workers, the effort for job stress management is needed to improve the work efficiency and the workers' quality of life.

• Journal of Astronomy and Space Sciences
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• v.32 no.4
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• pp.411-417
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• 2015

Several optical monitoring strategies by a ground-based telescope to protect a Geostationary Earth Orbit (GEO) satellite from collisions with close approaching objects were investigated. Geostationary Transfer Orbit (GTO) objects, Inclined GeoSynchronous Orbit (IGSO) objects, and drifted GEO objects forced by natural perturbations are hazardous to operational GEO satellites regarding issues related to close approaches. The status of these objects was analyzed on the basis of their orbital characteristics in Two-Line Element (TLE) data from the Joint Space Operation Center (JSpOC). We confirmed the conjunction probability with all catalogued objects for the domestic operational GEO satellite, Communication, Ocean and Meteorological Satellite (COMS) using the Conjunction Analysis Tools by Analytical Graphics, Inc (AGI). The longitudinal drift rates of GeoSynchronous Orbit (GSO) objects were calculated, with an analytic method and they were confirmed using the Systems Tool Kit by AGI. The required monitoring area was determined from the expected drift duration and inclination of the simulated target. The optical monitoring strategy for the target area was analyzed through the orbit determination accuracy. For this purpose, the close approach of Russian satellite Raduga 1-7 to Korean COMS in 2011 was selected.

• Korean Journal of Social Welfare
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• v.60 no.1
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• pp.103-125
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• 2008

Recently, it has been observed that social workers in Korea face diverse difficulties in designing social work programs. These difficulties require researchers to conduct a study on the contextual features of the difficulties. This study is to analyze the characteristics of the social work program proposals on the basis of program components. Research method used in the study is content analysis. Two researchers developed the analytic tool based on literature review and a pilot test, and analyzed 73 proposals submitted to a private welfare foundation from nationwide social work agencies in 2005 and 2006. As a result, although each program was designed in a proposal according to standardized form, there were creative diversities in designing social work programs. In addition, there were confusions in the three areas: conceptual and logical confusion, research and analytical confusion, and concrete and procedural confusion. Finally the researchers suggested several tasks and recommendations for the areas of research, education, and practice to solve these confusions in Korea.

• Culinary science and hospitality research
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• v.6 no.3
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• pp.25-55
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• 2000

AS the number of tourist has been increased. hotel industry will be able to not be existed and developed if not adapted to the need of customer's which is changed according to the change of Hotel's function. Traditionally. F&B department is enlarged compared to the past. But. it cause negative result in terms of clear profit. A menu is a marketing tool which delivers restaurant's image aid message to customers and communicate need and wants to restaurant. So far, studies on menu have been done in an analytical way from a management's viewpoint and inadequate to reflect customer's need and wants. A research on customer's menu selection procedure is critical to satisfying their needs and wants yield profit. This study examined the theories on menu-design and customer behavior through literature review and verified hypotheses through an empirical analysis. A questionnaire-survey had been used in luxury hotel's main grills and all most restaurants in Seoul. Collected data were analyzed. using SPSS/PC+ package. The important findings are as follows. In this study is to examine the factors that have an influence on customer's menu selection. The factors affected the customers' menu selection of hotel restaurant in the four factors. Four factors are hotel's restaurant of environmental factor. menu-choice factor. value of menu items, information. Correction between the evaluation criteria and selection of menu was examined. All four evaluation criteria, menu-choice factor was found to be most strongly collected with selection of menu. In conclusion, As a study on the Customer' menu Selection Behavior factor of Restaurant Menus in Hotels, It raises to exert us in the menu management of hotel restaurant.

• Korean Journal of Health Education and Promotion
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• v.18 no.2
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• pp.115-128
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• 2001

This study was carried out to offer the basic data for more qualitative lives of the adulthood with obesity through their health maintenance and control. So, the researcher reviewed and analyzed the health problems of the subjects according to sex, age, and positive rate on the screening tests. The subjects were 91 obese persons in K university hospital in Seoul from December 1, 2000 to January 31, 2001. A Questionnaire developed by researcher to obtain subject's general characteristics, main symptoms, medical examination, diagnosed disease was used as the tool for the study. The results of this study are as follows: 1. For the distribution of diagnosis in subjects, liver disease was most frequent and hypertension was second. 2 The most common complaints were indigestion in the digestive system, throat pain in the respiratory system, dyspnea in cardiovascular system, thirsty in endocrine system, frequent urine in the urinary system, vertigo in the hematologic system. 3. The main symptoms according to sex were for females, a statistically significant higher rate of complaints in the digestive system, musculoskeletal system as compared to males. 4. The main symptoms according to age were that in the fourth decade there were higher rate of complaints in the musculoskeletal system. 5. In screening tests according to sex, males showed a higher positive rate for Alk-Phosphatase and females, in FBS, urine-micro, VDRL. 6. In screening tests according to age, higher positive rates of BP, Chest X-ray, mammography, ESR, CRP were seen in the fourth decades. 7. Obesity was positively related to cardiovascular system, endocrine system, urinary system, musculoskeletal system, mental and nervous system in main symptoms. 8. Obesity was positively related to BP, Sonography, FBS, SGOT, SGPT in screening tests.

• Explosives and Blasting
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• v.36 no.3
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• pp.10-18
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• 2018

The dynamic behaviour of the rock mass under the dynamic load is different from the static application of the maximum load of the same size. An experimental approach to investigating rock behavior under dynamic loads is more difficult than that under static conditions in control of dynamic loads, measurement and analysis of the results. Numerical methods are less constrained by performing the experiments numerically, rather than experimental ones, so they can be very powerful analytical tool at the design stage. However, even if the algorithms of the analysis method are appropriate, careful analysis is required because the calculation results may vary largely depending on input data and boundary conditions. In this paper, when investigating the behavior of rock structures under dynamic load numerically, the effects of boundary conditions, dynamic load and calculation time step, and dynamic load characteristics on the calculation results were reviewed to provide guidance on setting up boundary conditions and calculation time step related to dynamic analysis.

• Journal of Korean Society of societal Security
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• v.1 no.2
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• pp.53-59
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• 2008

The lack of water resources is becoming a serious issue throughout the world. The water shortage in Korea is expected to increase. Groundwater can be a solution to this matter in some places. Especially, bank filtrations are known to be advantageous over conventional reserviors, even if they have some drawbacks such as their limited location for development and small sizes. The AHP(Analytic Hierarchy Process) is an analytical tool, supported by simple mathematics, which enables one to explicitly rank tangible and intangible factors against each other for the purpose of resolving conflicts or setting priorities. In order to check the applicability of AHP to the evaluation of bank filtration sites, four candidate locations were chosen. They have suffered from problems like water-supply shortage and delayed dam construction. The analysis results are compared with those of the previous study using a conventional method. It is believed that the developed method can a basis for reasonable decision-making regarding bank filtration development.