• Journal of Sensor Science and Technology
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• v.22 no.2
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• pp.111-117
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• 2013

The autonomous driving method using magnetic sensors recognizes the position by measuring magnetic fields in autonomous robots or vehicles after installing magnetic markers in a moving path. The Position estimate method using magnetic sensors has an advantage of being affected less by variation of driving environment such as oil, water and dust due to the use of magnetic field. It also has the advantages that we can use the magnet as an indicator and there is no consideration for power and communication environment. In this paper, we propose an efficient sensor system for an autonomous driving vehicle supplemented for existing disadvantage. In order to efficiently eliminate geomagnetism, we analyze the components of the horizontal and vertical magnetic field. We propose an algorithm for position estimation and geomagnetic elimination to ease analysis, and also propose an initialization method for sensor applied in the vehicle. We measured and analyzed the developed system in various environments, and we verify the advantages of proposed methods.

• Herbal Formula Science
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• v.18 no.2
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• pp.215-225
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• 2010

In order to investigate the antidepressant effects of Lycii Radicis Cortex on the change of HPA-Axis system, the forced swimming test was performed. The expressions of CRF and c-Fos in the PVN were measured with immunohistochemical method and the concentration of ACTH in Serum was evaluated with ELISA method. And the results obtained were as follows. Results : 1. The duration of immobility in the forced swimming test was significantly decreased in the LRC100 group and the LRC400 group(P<0.001). 2. The expressions of CRF and c-Fos were significantly reduced in the LRC100 group and the LRC400 group(P<0.001). And the concentration of ACTH in Serum were significantly reduced in the LRC 100 group(P<0.05). According to the results above mentioned, it can be considered that Lycii Radicis Cortex has antidepressant effects.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.981-988
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• 2018

In order to acquire an accurate TOF, this paper proposes a method that produces TOF by using a mathematical model for the envelope of the received signal obtained from a system dynamic model of ultrasonic transducer. The proposed method estimates the arrival time of the received signal retrospectively by comparing its wave form obtained after triggering point with its mathematical envelope model. Experimental result shows that the error due to variation of triggering point can be dramatically decreased by implementing the proposed method.

• Journal of the Korean Magnetics Society
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• v.10 no.6
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• pp.302-309
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• 2000

An MFL (Magnetic Flux Leakage) testing system has been developed in order to inspect the non-metallic inclusions in the thin steel sheets. We have made a differential type flux-gate magnetometer using the measurement of apparent coercive field strength of soft magnetic core. The specifications of the electromagnet was determined using FEM software, and MFL testing system with 3 axis degree of freedom was constructed. The feasibility testing for non-metallic inclusion was shown using the system. By digitizing MFL signal and using 2-D graphic display, we could identify various surface defects other than the inclusions.

• Journal of Information Management
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• v.38 no.2
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• pp.59-83
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• 2007

This study develops and presents data modeling and metadata elements in order to build system based on FRBR for music resources. This process intends to build bibliographic system to systematically manage and efficiently retrieve music resources.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.620-630
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• 2018

In this paper, a positioning method of distributed power system is proposed to minimize the average voltage variation of a DC microgrid through voltage sensitivity analysis. The voltage sensitivity under a droop control depends on the position of the distributed power system. In order to acquire a precise voltage sensitivity under a droop control, we analyzed the power flow by introducing a droop bus with the considerations of the droop characteristics. The results of the positioning method are verified through PSCAD/EMTDC simulation.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1100-1102
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• 1998

This paper presents the Two-Phase Neural Network(TPNN) to slove the Optimal Economic Environmental Dispatch problem of thermal generating units in electric power system. The TPNN, Compared with other Neural Networks, is very accurate and it takes smaller computer time for a optimization problem to converge. In this work, in order to provide useful information to the system operator, we are used the total environmental weight and relative weighting of individual insults(e.g., $SO_2$, $NO_X$ and $CO_2$) also, presented the simulation results of the dispatch changes according to the weights. The Two-Phase Neural Network is tested on a 11-unit 3-pollutant system to prove of effectiveness and applicability.

• Journal of the Ergonomics Society of Korea
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• v.26 no.2
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• pp.123-129
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• 2007

In 2003 the Korean Government introduced 'the risk factors analysis system' in order to prevent the work-related musculoskeletal disorders. In addition, the proclamation by the Ministry of Labor delineated eleven spheres of work associated with musculoskeletal disorders. According to Occupational Safety and Health Regulations, business proprietors who have workers engaged in tasks associated with musculoskeletal disorders are required to carry out a survey on risk factors every three years. Effective risk factors analysis principles and practices will succeed by refining the workplaces continuously. However, numerous difficulties arise during the application of risk factors analysis to the various industries. We discuss a number of issues related to risk factors analysis system, and suggest a number of directions for future work in this area.

• Steel and Composite Structures
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• v.27 no.4
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• pp.465-477
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• 2018

In this research, vibration and smart control analysis of a concrete foundation reinforced by $SiO_2$ nanoparticles and covered by piezoelectric layer on soil medium is investigated. The soil medium is simulated with spring constants and the Mori-Tanaka low is used for obtaining the material properties of nano-composite structure and considering agglomeration effects. With considering first order shear deformation theory, the total potential energy of system is calculated and by means of Hamilton's principle in three displacement directions and electric potential, the six coupled equilibrium equations are obtained. Also, based an analytical method, the frequency of system is calculated. The effects of applied voltage, volume percent and agglomeration of $SiO_2$ nanoparticles, soil medium and geometrical parameters of structure are shown on the frequency of system. Results show that with applying negative voltage, the frequency of structure is increased.

• Smart Structures and Systems
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• v.21 no.2
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• pp.187-194
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• 2018

This paper focuses on the $H_{\infty}$ filter design problem for offshore steel jacket platforms. Its objective is to design a full-order state observer for offshore platforms in presence of unknown disturbances. To make the method more practical, it is assumed that the measured variables are available at discrete-time instants with time-varying sampling time intervals. By modelling the sampling intervals as a bounded time-varying delay, the estimation error system is expressed as a time-delay system. As a result, the addressed problem can be transformed to the problem of stability of dynamic error between the system and the state estimator. Then, based on the Lyapunov-Krasovskii Functional (LKF), a stability criterion is obtained in the form of Linear Matrix Inequalities (LMIs). According to the stability criterion, a sufficient condition on designing the state estimator gain is obtained. In the end, the proposed method is applied to an offshore platform to show its effectiveness.