• The Journal of the Korea institute of electronic communication sciences
• /
• v.18 no.4
• /
• pp.701-708
• /
• 2023

Local governments are required to take measures to prevent occupational accidents under Articles 4(2) and 4(3) of the Occupational Safety and Health Act, and this study suggested the necessity of establishing an IT-based integrated safety and health information sharing system for serious accident reduction and safety and health management through the case of Incheon Metropolitan City. Recently, as local governments have established labor and health ordinances and basic plans, the need for an independent integrated safety and health management system based on local industrial characteristics has increased. It is necessary to establish a cooperation and support system with basic local governments and hub institutions, share integrated safety and health information with related institutions and organizations, and play a pivotal role in regional safety and health management by managing occupational accident statistics and implementing basic policies. The system through local governments' safety and health management will reduce serious accidents in the region, and the comprehensive safety and health management system for small businesses and projects ordered by local governments will strengthen the operability of the site, which will be effective in preventing critical accidents and industrial accidents.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
• /
• v.6 no.3
• /
• pp.191-202
• /
• 2016

Social distance can indicate cognitive and behavioral attitudes toward a social group, and is useful for investigating people situated in a socially vulnerable position. When the children from multicultural family aware negative attitudes from peer Korean children, self-confidence and social competence can be disturbed. This study intended to examine influential factors on children's social distance towards children from multicultural families including multicultural contact experience, stereotype, ethnically homogeneous nationalism, thereby providing empirical evidence on social distance regarding multicultural families and their children. The results of this study are as follows. First, when the Korean children felt closeness with a multicultural child, when the ethnicity of the foreigner resided in the neighbor is White or Black, when they contact multicultural children through the media and a multicultural education, the level of social distance was higher, while the neighbor's ethnicity is Abrab, social distance was lower. Second, there was a significant association between the higher level of Korean children's positive cognition and emotion and the lower level of social distance. Third, hierarchial regression analyses demonstrated that positive emotion and cognition decreased the level of social distance, while both closeness with a multicultural child and taking the multicultural education increased the level of social distance. Finally, based on these results, this study suggested implications for social work practice and research to better understand and reduce children's social distance towards children from multicultural families.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.4D
• /
• pp.671-678
• /
• 2006

In this study, to describe vehicle-structure dynamic interaction phenomena with 1/4 vehicle model, nonlinear Hertzian contact spring and nonlinear contact damper are adopted. The external loads acting on 1/4 vehicle model are selfweight of vehicle and geometry information of running surface. The constraint equation on contact surface is implemented by the Penalty method with stabilization and the reaction from constraint violation. To describe pitching motion of various vehicles two types of the displacement constraint equations are exerted to connect between car bodies and between bogie frames, i.e., the rigid body connection and the rigid body connection with pin, respectively. For the time integration of dynamic equations of vehicles and structure Newmark time integration scheme is adopted. To reduce the error caused by inadequate time step size, adaptive time-stepping technique is also adopted. Thus, it is expected that more versatile dynamic interaction phenomena can be described by this approach and it can be applied to various railway dynamic problems with low computational cost.

• The Journal of the Convergence on Culture Technology
• /
• v.10 no.4
• /
• pp.437-442
• /
• 2024

The unification of the Korean Peninsula is not only a national aspiration but also holds significant economic implications. By maximizing the economic synergy between South and North Korea and reconstructing the North Korean economy, balanced development across the peninsula can be promoted. However, the unification process will face various economic challenges, including the substantial costs of unification, integrating different economic systems, and bridging the economic disparity between the two Koreas. This paper aims to analyze these anticipated economic issues and propose systematic and phased solutions. Specifically, it discusses the objective estimation of unification costs and funding strategies, suggests effective integration methods for the disparate economic systems of the two Koreas, and identifies policy tasks to reduce economic disparities. The paper reviews existing studies on unification costs, explores strategies for the balanced development of South and North Korean economies through industrial restructuring and gradual transition to a market economy, and proposes concrete measures such as the expansion of North Korea's social overhead capital (SOC) and the development of human capital. The goal is to establish a solid economic foundation for peaceful unification and create opportunities for the economic resurgence of the Korean Peninsula.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.11B no.3
• /
• pp.112-118
• /
• 2001

In the near future, the voltage of power system for passenger vehicle will be changed to 42V from existing 14V./ Because of increasing power and voltage ratings used in the vehicle the motor drive system has high switching dv/dt and it generates electromagnetic interference (EMI) To solve these problems multi-level inverter system may be used The feature of multi-level inverter is the output voltage to be synthesized from several levels of voltage Because of this feature high switching dv/dt and EMI can be reduced in the multi-level inverter system But as the number of level is increased manufacturing cost is getting expensive and system size is getting large. Because of these disadvantages the application of multi-level inverter has been restricted only to high power drives. The method to reduce manufacturing cost and system size is to integrate circuit of multi-level inverter into a few chips But isolated power supply and signal isolation circuit using transformer or opto-coupler for drive circuit are obstacles to implement the integrated circuit (IC) In this paper a drive circuit of 4-level inverter suitable for integration to hybrid or one chip is proposed In the proposed drive circuit DC link voltage is used directly as the power source of each gate drive circuit NPN transistors and PNP transistors are used to isolate to transfer the control signals. So the proposed drive circuit needs no transformers and opto-couplers for electrical isolation of drive circuit and is constructed only using components to be implemented on a silicon wafer With th e proposed drive circuit 4- level inverter system will be possible to be implemented through integrated circuit technology Using the proposed drive circuit 4- level inverter system is constructed and the validity and characteristics of the proposed drive circuit are proved through the experiments.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.1 no.1
• /
• pp.1-10
• /
• 1997

Current seismic design philosophy for reinforced concrete (RC) structures on energy dissipation through large inelastic defomations. A nonlinear dynamic analysis which is used to represent this behavior is time consuming and expensive, particularly if the computations have to be repeated many times. Therefore, the selection of an efficient yet accurate alogorithm becomes important. The main objective of the present study is to propose a new technique herein called the prediction approach with siffness measure (PASM) method in the convetional direct integration methods, the triangular decomposition of matrix is required for solving equations of motion in every time step or every iteration. The PASM method uses a limited number of predetermined decomposed effective matrices obtained from stiffness states of the structure when it is deformed into the nonlinear range by statically applied cyclic loading. The method to be developed herein will reduce the overall numerical effort when compared to approaches which recompute the stiffness in each time step or iteration.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
• /
• v.39
• /
• pp.281-310
• /
• 2008

An understanding of importance of port has increased according to the in and out environment changes surrounding port. And the jurisdiction of physical distribution including port logistics integrated to Ministry of Land, Transport and Maritime Affairs. It is a good time for review the related port law once more. Present related port law has no problems itself. But because there are many laws about port, so overlap is shown in many aspects. According to this viewpoint, this study has focused to reduce the overlap in the contents of the laws and propose the improvement methods. So as to achieve this goal, I divided study fields into three aspects. The first is the subject of port management and second is the object of port management, the third is contents of port management. And also improvement plan provided in three aspects. Improvement plan is as follows. Firstly, the diversity of management subject is reduced considerably due to the integration of government organization but the problem which what laws among the various laws would adopt to same object is still remained. So it is necessary to make into one or two laws. Secondly, in the case of object of port management, it is essential to cover the port, port facilities and port hinterland with one comprehensive law. Therefore it is important to adjust the related clauses in various laws. Thirdly, in connection with the contents of port management, port development plan or other related port business and etc. described in various laws have to cordinated. At the same time, it is desirable that the similar terminology used in various laws would be unified.

• Journal of Korea Multimedia Society
• /
• v.11 no.2
• /
• pp.269-280
• /
• 2008

The information flow through RFID techniques such as, standardized EPC and EPCglobal network suggests new change in the method of cooperating and sharing information in the supply chain. Common function should be prepared for communication, security techniques, and business processes based on the EPCglobal standard to introduce efficient RFID techniques. And the standard architecture which can deal with the RFID environment flexibly is quite necessary. Therefore, this paper suggests Enterprise Application Framework (EAF) for developing efficient and secure RFID applications. EAF offers essential services to develop RFID enterprise systems : a communication environment which uses various standard communication protocols, a security function based on PKI, and abstract business services for flexible introduction of RFID businesses. It simplifies the RFID business integration, minimizes the development complexity, and thus EAF is expected to reduce the cost of RFID application development. EAF guarantees constructing secure RFID applications due to PKI-based security mechanism.

• Journal of Institute of Control, Robotics and Systems
• /
• v.7 no.10
• /
• pp.812-818
• /
• 2001

This paper proposes an optimum design method of structural and control systems, taking a 2-D truss structure as an example. The structure is supposed to be subjected to initial static loads and disturbances. For the structure, a FEM model is formed, and using modal transformation, the equation of motion is transformed into that of modal coordinates in order to reduce the D.O.F. of the FEM model. The structure is controlled by an output feedback $H^$\infty$$ controller to suppress the effect of the disturbances. The design variables of the simultaneous optimal design of control-structure systems are the cross sectional areas of truss members. The structural objective function is the structural weight. The control objective function is the $H^$\infty$$ norm, that is, the performance index of control. The second structural objective function is the energy of the response related to the initial state, which is derived from the time integration of the quadratic form of the state in the closed-loop system. In a numerical example, simulations have been carried out. Through the consideration of structural weight and $H^$\infty$$ norm, an advantage of the simultaneous optimum design of structural and control systems is shown. Moreover, while the optimized performance index of control is almost kept, we can acquire better design of structural strength.

• Journal of Institute of Control, Robotics and Systems
• /
• v.17 no.1
• /
• pp.61-67
• /
• 2011

The GPS new civil signal is modulated on the L2 carrier at a frequency of 1227.6MHz. The L2C signal is composed of two multiplexed code signals, which include CM code with a 10,230 chip sequency repeating every 20ms, and CL code which has a 767,250 chip sequency repeating every 1.5 seconds. Thus, the new civil signal have much improved cross correlation properties so that the position fixing can be possible even with very weak signals. However, it requires very long acquisition time because of its long code length. This paper presents an efficient signal acquisition method for L2C AGPS receiver. Snapshot mode and coarse time assistance are assumed and total integration time is given by 1.5 sec. By SNR worksheet and computer simulation, it is proven that L2C signal can be acquired with very weak power less than -150dBm. Considering the acquisition time and the sensitivity, it is recommended that the highest power signal is acquired with CM code first to reduce TTFF. By the timing synchronization, at this time, search space of the code phase for other signals can be greatly reduced so that CL code can be used in signal acquisition to maximize sensitivity with small computation.