• Journal of the Korean Society for Railway
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• v.2 no.3
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• pp.36-45
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• 1999

The basic idea of cable-stayed girder bridges is the utilization of high strength cables to provide intermediate supports for the bridge girder so that the girder can span a much longer distance. In the cable-stayed bridge, the cables exhibit nonlinear behavior because of the change in sag, due to the dead weight of the cable, which occurs with changing tension in the cable resulting from the movement of the end points of the cable as the bridge is loaded. Techniques required for the static analysis of cable-stayed bridges has been developed by many researchers. However, little work has been done on the dynamic analysis of such structures. To investigate the characteristics of the dynamic response of long-span cable-stayed bridges due to various dynamic loadings likes moving traffic loads. two different 3-D cable-stayed bridge models are considered in this study. Two models are exactly the same in structural configurations but different in finite element discretization. Modal analysis is conducted using the deformed dead-load tangent stiffness matrix. A new concept was presented by using divided a cable into several elements in order to study the effect of the cable vibration (both in-plane and swinging) on the overall bridge dynamics. The result of this study demonstrates the importance of cable vibration on the overall bridge dynamics.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.5
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• pp.85-98
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• 1993

A method of analysis for the material and geometric nonlinear analysis of planar prestressed concrete cable-stayed bridges including the time-dependent effects due to load history, creep, shrinkage, aging of concrete and relaxation of prestress is described. The analysis procedure, based on the finite element method, is capable of predicting the response of these structures through elastic, cracking, inelastic and ultimate ranges. The nonlinear formulation for the description of motion is based on the updated Lagrangian approach. To account for the material nonlinearity, nonlinear stress-strain relationship and cracking of concrete, nonlinear stress-strain relationships of reinforcing steel, prestressing steel, and cable, including load reversal are given. Results from a numerical examples on ultimate analyses of cable-stayed bridges are presented to illustrate the analysis method.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.1040-1047
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• 2006

Bridges are exposed to constantly changing weather conditions and temperature. The temperature change is induced by a change in atmospheric temperature and solar radiation. Atmospheric temperature change acts on the whole structure. Thus, it is relatively easy to consider in the design. Solar radiation, however, causes un-uniform temperature distribution in the structure, depending on the shape of the structure and its shadows. Un-uniform temperature distribution causes a torsional moment in bridge section and a deformation of bridge. A deformation can make differences of dynamic and static behavior of bridge. In this study, the method for analysis of static and dynamic behavior considering deformation and changes of material properties due to temperature variation was developed. By this method, it is found from dynamic analysis results that the change of frequency in analysis model is similar with test results of public used cable-stayed bridge. When a temperature goes down, a frequency goes up. And it is found that the change of frequency is affected by the change of material properties.

• Journal of the military operations research society of Korea
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• v.32 no.1
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• pp.188-212
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• 2006

The purpose of this study is to extract relavant factors that affect military accidents. A survey was conducted for 227 officers and noncommissioned officers and 300 private soldiers. The survey results extracted 9 important factors that cause military accidents, including 3 troop factors, 3 social environment factors, and 3 personal character factors. Through a regression analysis using these 9 factors as independent variables and 4 types of military accidents as dependent variables, several factors were found to be very useful to explain military accidents. The findings of this study can be used to develop an early warning system for military accidents reduction.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.9
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• pp.34-42
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• 2010

Agricultural automation has become more and more important by environmental change. The automation demands the highest technology due to the ever changing various conditions in agriculture system. In the paper, semi-autonomous pesticide spray robot system has been developed for rose farming in the glass house. The robot is in autonomous mode during pesticide spraying process driven on pipe rail. The robot is manually driven while moving from a rail to the next rail. The drive platform and autonomous operation control system are developed based on IT fusion technology. The pesticide spray system is also developed with nozzles and booms for precision mist spray system. Experimental data of nozzle test is also included.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.6
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• pp.1499-1504
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• 2012

This challenge trying to bag earlier when soldiers prefer to learn what they do not prefer those factors suggested in the bag so that the business can be a smooth transition. Subject research results are as follows. First, the preferences of the average of the soldiers on the previous business bag. 4.00, respectively. Dual prefer that the most important responsibility (4.11) and the efforts of sex and adequacy were analyzed. Second, the male soldiers (3.96) M yeobyeol preference emphasis on commitment and accountability, while a woman soldier (4.12) to be a lot of interest in the adequacy and sotongseong analyzed. Third NCO Title By expertise and responsibilities from the outset, while the officer adequacy utmost importance.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.1
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• pp.56-66
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• 2017

This paper investigates university-level curriculum by comparing education systems among maritime universities, fishery universities and naval academy. It was found that maritime university programs are full of effective courses related to the concept of Sea Power along with the duties of maritime officers. It is recommended that more interest be paid to on the increase of national sea power by renovating current educational systems and adding more national supports by providing additional maritime policies to establish sustainable development goals for Sea Power.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.238-241
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• 2022

North Korea launched an ICBM and declared Moratorium for the September 19 military talks. The Armed Forces must protect military security for national defense and security. The Ministry of National Defense, which received a hacking attack from North Korea, must protect its military security even more. Recently, the leakage of military data through smartphones is occurring through smartphones. Officers and non-commissioned officers can use smartphones while working. Therefore, smartphone forensics is required to check information leakage of military data from smartphones. In this study, forensic leaks of military data from the Galaxy S20 model of S company. Research integrity verification for securing smartphone forensic evidence, securing metadata, and adopting evidence. This study will contribute to the development of military security and forensic technology.

• Convergence Security Journal
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• v.24 no.1
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• pp.95-105
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• 2024

Although the importance of reserve forces has been emphasized again since the outbreak of the Ukraine War, there is a serious shortage of so-called mid-level officers such as field officers, non-commissioned officers, sergeants, and sergeant s in the Army. This is because, according to related laws such as the Military Personnel Mannagement Act, mid-level executives who have served for more than 20 years can choose to retire. To solve this problem, we studied recent papers spanning 10 years from April to July 2023. As a result of the study, first, mid-level executives must serve in the reserve forces for at least 5 years after expiration of active duty service. Second, the reserve force promotion system must be reorganized to eliminate restrictions on number and rank. In addition, the significance and implications of the study and future directions were discussed.

• Journal of National Security and Military Science
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• s.1
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• pp.155-190
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• 2003

The objective of this study is to provide basic information for planning and practicing social welfare services for married nurse officers serving in the Korean military. For such a purpose, this study identifies the difficulties which married nurse officers have faced and the necessary services which are supposed to alleviate them. The data were collected by sending a questionnaire to 114 married nurse officers from July 16 to August 10, 2001. The results of this study are as follows: First, the married nurse officers were relatively dissatisfied with such domains as child care and education, health, and housing. And among the thirty-four problems, the married nurse officers expressed the most serious dissatisfaction with the difficulty in attending the events held in child's school, lack of children's dormitory run by the military, difficulty in adjusting to the school due to frequent house-moving, and limited access to dental care. Second, the married nurse officers needed services in domains such as housing, child care and education, and health. Specifically, they wanted the military-run housing, child care facility within military hospitals, maternity leave for child care and education, extension of risk allowances, and support for BOQ. Third, with regard to the seriousness of problems as well as the priority of services, the married nurse officers gave higher priority to such domains as child care and education, health, and housing. These results indicate that married nurse officers were to the largest extent concerned with these three domains and that they had the urgent need for services relevant to those domains. The importance of routine need assessments as well as solutions to the family-related problems for married nurse officers is therefore suggested in this study.