• Nuclear Engineering and Technology
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• v.48 no.5
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• pp.1083-1095
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• 2016

The design of Prototype Gen-IV Sodium-Cooled Fast Reactor (PGSFR) has been developed and the validation and verification (V&V) activities to demonstrate the system performance and safety are in progress. In this paper, the current status of test activities is described briefly and significant results are discussed. The large-scale sodium thermal-hydraulic test program, Sodium Test Loop for Safety Simulation and Assessment-1 (STELLA-1), produced satisfactory results, which were used for the computer codes V&V, and the performance test results of the model pump in sodiumshowed good agreement with those in water. The second phase of the STELLA program with the integral effect tests facility, STELLA-2, is in the detailed design stage of the design process. The sodium thermal-hydraulic experiment loop for finned-tube sodium-to-air heat exchanger performance test, the intermediate heat exchanger test facility, and the test facility for the reactor flow distribution are underway. Flow characteristics test in subchannels of a wire-wrapped rod bundle has been carried out for safety analysis in the core and the dynamic characteristic test of upper internal structure has been performed for the seismic analysis model for the PGSFR. The performance tests for control rod assemblies (CRAs) have been conducted for control rod drive mechanism driving parts and drop tests of the CRA under scram condition were performed. Finally, three types of inspection sensors under development for the safe operation of the PGSFR were explained with significant results.

• Convergence Security Journal
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• v.19 no.3
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• pp.71-79
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• 2019

The demand of smart cars is increasing rapidly. International stand organize such as 3GPP and 5GAA are proposing standard communication protocvols for connected-car, and automotive network infrastructure. But Smart car network have many security threats and more dangerous against the existed wire communication network. Typically, peripheral devices of a smart car may disguise their identity and steal location information and personal information about the vehicle. In addition, the infrastructure elements around smart cars can conspire and put driving cars in danger, threatening lives. This is a very serious security threat. Therefore, in order to solve these problems, we proposed a system that is secure from collusion and tampering attacks using attribute-based authorize delegation method and threshold encryption algorithms. We have demonstrated using a semantic safety model that the proposed system can be safe from collusion attack.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.1
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• pp.1-7
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• 2012

This paper introduces the mechanical design, fabrication, and control of a biomimetic fish robot whose driving motions resemble a real fish's flexibility and movement. This robot uses two motors create flexible movement like that of a fish. Several schemes, such as neutral buoyancy, fast underwater swimming, and direction changes, are introduced. The tail of the fish robot is made of a polymer material for flexible movement. The interior of the tail contains a joint and a wire. A sine wave command was applied to the tail to produce motion resembling a real fish swimming, and a buoy control device was installed. The up and down motion of the robot fish was controlled using this device.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.6
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• pp.434-440
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• 2023

This paper propose the method that measure the main system parameters for current control of a.c. motor adopting the vector control technique. The automatical method that tuning PI control gains for current control of servo motors are used frequently through the information of main system parameters, wire resistance and inductance. In this study, the techniques to measure these two system parameters through the control of 3-phase inverter are presented. These control and measuring method are implemented by measuring output phase current obtained as a results of the step current control using simple proportional feedback input. Moreover, this method use freewheeling current of inverter at special switching mode for measuring inductance. This analytic strategy is could measure and calculate the system parameters without the complex measurement algorithm and new additional measuring circuits. That is could measure the total resistance and total inductance including wiring resistance and conduction resistance of switching devices using real driving circuits to control the motors.

• Proceedings of the KIPE Conference
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• 2009.11a
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• pp.105-110
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• 2009

The On Line Electric Vehicles(OLEV) that can pick up inductive power from underground coils on driving with high efficiency have been developed this year, and is now proposed in this paper. The IPS(Inductive Power Supply) system consists of power supply inverters, power supply rails, pick up modules, and a regulator. There are 3 generations of IPS have been developed so far, and the $4^{th}$ generation IPS is being developed. The $1^{st}$ generation has been demonstrated this Feb. 27, which is equipped with mechanically auto tracking pick-up module with 1cm air gap, and showed 80% power efficiency. The $2^{nd}$ generation IPS applied to an 120kW (average)/240kW(peak) motor powered electric bus has 17cm air gap with 72% power efficiency. For the $2^{nd}$ generation IPS, the Power supply inverter has 440V, 3phase input and 200A @ 20kHz output. The test power supply rail of 240m long is segmented by 60m each, where newly developed core structure and power cable are constructed under the road covered with asphalt of 5cm thickness. The pick-up modules which consist of core, winding wire, and rectifiers are fixed to the bottom of the bus which can carry more than 40 passengers and can pick up max. 60kW. To remove parasitic component and to transfer maximum power between them resonant circuit topology is applied to the primary and secondary sides. The EMF level is below 62.5mG at 1.75m from the center of the road to meet the regulation. Several effective ways of reducing EMF levels have been developed. In addition, effective ways to solve problems related high frequency power cables buried in ground and it's proof from soil have been studied also. This development shows that the IPS system is capable of supplying enough power to the pick-up of OLEV and can reduce battery size, weight and cost, which means the IPS with OLEV is one of the best candidate for EV.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.578-585
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• 2018

This paper proposes a design method for a 3-phase interior permanent magnet synchronous motor (IPMSM) and clamping force control method for an electro-mechanical brake (EMB) using co-simulation for a high-speed train (HST). A traditional pneumatic brake system needs much space for the compressor, brake reservoir, and air pipe. However, an EMB system uses up to 50% less space due to the use of a motor and electric wires for controlling the brake caliper. In addition, it can reduce the latency time for brake control because of the fast response and precise control. A train that has many brakes is advantageous for safety because of the control by sharing the braking force. In this paper, a driving method for a cam-shaft-type EMB is modeled. It is different from the ball-screw-type brakes that are widely used in automobiles. In addition, a co-simulation method is proposed using JMAG and Matlab/Simulink. The IPMSM was designed and analyzed with the JMAG tool, and the control system was simulated using Matlab/Simulink. The effectiveness of the co-simulation results of the mechanical clamping force and braking force was verified by comparison with the clamping force specifications of a HEMU-430X HST.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.11
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• pp.2689-2696
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• 2015

Radioactive isotopes which are manufactured using a cyclotron in a radioisotope used for radiation diagnosis is affected by the production yield according to size and shape of the beam and beam uniform degree from irradiated location when the proton beam investigated the target by cyclotron. Therefore, in this paper developed the BPM(Beam Profile Monitor) device capable of measuring the beam cross-section at the cyclotron beam line. It was configured so as to be able to remote control the BPM device in LabView and used the BPM program it was to be able to easily monitor and display to analyze the graph of two-dimensional graph and a three-dimensional beam distribution numerical information of the beam obtained while scanning the tungsten wire to the X and Y axis. The time it takes to measure the beam can be confirmed 37seconds when step motor driving speed was 2000pps. Through a beam readjusted based on the measured beam distribution information by optimizing the beam distribution it can be made to maximize the RI production yield and contribute supply stabilization.