• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.1
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• pp.5-24
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• 2010

Data fusion is an attractive technology because it allows various trade-offs related to performance metrics, e.g., energy, latency, accuracy, fault-tolerance and security in wireless sensor networks (WSNs). Under a complicated environment, each sensor node must be equipped with more than one type of sensor module to monitor multi-targets, so that the complexity for the fusion process is increased due to the existence of various physical attributes. In this paper, we first investigate the process and performance of multi-attribute fusion in data gathering of WSNs, and then propose a self-adaptive threshold method to balance the different change rates of each attributive data. Furthermore, we present a method to measure the energy-conservation efficiency of multi-attribute fusion. Based on our proposed methods, we design a novel energy equilibrium routing method for WSNs, viz., multi-attribute fusion tree (MAFT). Simulation results demonstrate that MAFT achieves very good performance in terms of the network lifetime.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.2
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• pp.1-5
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• 2011

For measuring quad-band module system using WiBro network, frequency converter was developed. The size of the fabricated frequency converter is $3.1cm{\times}3.1cm{\times}0.4cm$. Noise figure of the receiver part of the frequency converter was 2.62 ~ 3.45 dB, EVM of that is -37.5 dB ~ -34.5 dB. And EVM of the transmission part was -42.5 ~ -35.5 dB. Quad-band module was fabricated with the developed frequency converter. Testing the quad-band module in 2.3 GHz WiBro network results the excellent internet connection for 2.5 GHz, 3.5 GHz and 5.5 GHz band.

• The Journal of Sustainable Design and Educational Environment Research
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• v.16 no.2
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• pp.54-63
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• 2017

The various colors and transparency of DSC and operability unrelated with directions greatly expand the use of BIPV, as a multi-functional composite of module. Therefore the possibility of DSC BIPV is examined by the case study and the analysis and then its applicability is examined. Most of the DSC BIPVs, which are found through a total of six case studies and analyzes in Korea and abroad, are mainly implemented with window glass and shading devices. This is related to the DSC transparency property. Improvements are due to the irritation of the eye due to the color of the red module. Therefore, it is important to take into account the color of the BIPV window depending on the use of the building and the room. Meanwhile, some colors of application model may stimulate eyes and such colors should be considered by use of buildings and rooms in the application of BIPV window. DSC BIPV has prospective diffusibility with the development of flexible module for the application of building surface.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.6
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• pp.585-592
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• 2014

In this study, a multibody simulator was developed to analyze the bio-mimetic motion of a lizard robot design. A RecurDyn multibody dynamics model of a lizard was created using a micro-computerized tomography scan and motion capture data. The bio-mimetic motion simulator consisted of a trajectory generator, an inverse kinematics module, and an inverse dynamics module, which were used for various walking motion analyses of the developed lizard model. The trajectory generation module produces spinal movements and gait trajectories based on the lizard's speed. Using the joint angle history from an inverse kinematic analysis, an inverse dynamic analysis can be carried out, and the required joint torques can be obtained for the lizard robot design. In order to investigate the effectiveness of the developed simulator, the required joint torques of the model were calculated using the simulator.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.2
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• pp.145-152
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• 2009

Currently almost all in-service-inspection techniques, applied in domestic nuclear power plants, are partial to field inspection technique. These kinds of techniques are related to managing nuclear power plants by the operation of foreign-produced inspection devices. There have been so many needsfor development of native in-service-inspection device because there is no native diagnosis device for nuclear power plant inspection yet in Korea. In this research, we developed several core techniques to make an automated ultrasonic pipe inspection system for nuclear power plants. A high performance multi-channel ultrasonic pulser/receiver module, an A/D converter module and a digital main CPU module were developed and the performance of the developed modules was verified. The S/N ratio, noise level and signal acquisition performance of the developed modules showed proper level as we designed in the beginning.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.6
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• pp.504-513
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• 2009

This paper proposes the new type LED driver modularization for illumination LED driver. The proposed LED driver circuit insulates a hot GND of AC input power and a cold GND of LED driver part by using a fly-back converter. In order to control easily the current of the LED, the fly-back converter is operated in the discontinuous mode with excellent dynamic characteristics, and the characteristics of the LED are verified after the closed loop control is performed using a KIA2431. The LED driver module allows the wide AC power input ranges and realizes the burst dimming function which directly regulates a PWM control IC. This paper describes the operation principle of the LED driver module and it is proved the usefulness through the real model with experimentation. Besides, this paper proposes the multi-channel LED driver which the miniaturized and modularized LED driver module are connected by parallel, and verified its propriety by experiments.

• Membrane Journal
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• v.27 no.5
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• pp.449-457
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• 2017

In this study, the 10 stages stacked module was designed by increasing the number of unit cells in the membrane capacitive deionization(MCDI) process. The aminated polysulfone and sulfonated poly(ether ether ketone) were synthesized and coated on porous carbon electrode by casting method. The salt removal efficiency was measured for the 10 stage stacked module under the operation conditions of adsorption voltage and time, desorption voltage and time, flow rate and concentration of feed water, and di-valent solutions including $CaSO_4$, $MgCl_2$ and tap water. Typically, when 100 mg/L of NaCl as the feed was used, the salt removal efficiency was 98.3% at a flow rate of 100 mL/min, the adsorption condition of 1.2 V/3 min and desorption condition of -0.5 V/5 min.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.11
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• pp.1109-1117
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• 2017

In this work, a new control module and communication system associated with DSP are proposed to overcome the limitations of the contemporary prevailing PLC-based industrial equipment controller, and the performance of the proposed system was experimentally verified. In the light of this issue, a communication conversion scheme from RS-485 to Modbus, the dominant communication protocol used by PLC, was developed and shown to yield enhanced compatibility between devices. The proposed system allows for ~50％ cost reduction as well as downsizing of the industrial controllers. Furthermore, the design includes 24 V general digital I/O pins, which facilitate partial expansion of inputs and outputs. With Modbus communication implemented in DSP with the RS-485 interface, multi-to-multi communication may also be achieved.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.2
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• pp.70-77
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• 2010

This study proposed an auto focusing method for a multi-focus image in assembling lens modules in digital camera phones. A camera module in a camera phone is composed of a lens barrel, an IR glass, a lens mount, a PCB board and aspheric lenses. Alignment among the components is one of the important factors in product quality. Auto-focus is essential to adjust image quality of an IR glass in a lens holder, but there are two focal points in the captured image due to thickness of IR glass. So, sharpness, probability and a scale factor are defined to find desired focus from a multi-focus image. The sharpness is defined as clarity of an image. Probability and a scale factors are calculated using pattern matching with a registered image. The presented algorithm was applied to a lens assembly machine which has 5 axes, two vacuum chucks and an inspection system. The desired focus can be determined on the local maximum of the sharpness, the probability and the scale factor in the experiment.

• Progress in Superconductivity
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• v.7 no.2
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• pp.114-119
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• 2006

High critical current density, high n value, multiple faults endurances, and fast recovery characteristics of YBCO thin films are very attractive characteristics for developing resistive type superconducting fault current limiters. But due to the limited current and voltage ratings of one YBCO module, it is needed to construct series and parallel module connections for high capacity electric networks. Especially for distribution network, more than 30 units should be connected in series to meet voltage level. So in order to construct distribution-level superconducting fault current limiter, simultaneous quench in one YBCO thin films should be realized, and furthermore, quench should be occurred in all fault current limiting units equally to avoid local heating and failures. In this paper, we proposed optimum design of YBCO thin films for fault current limiting module and technical method using shunt resistor to achieve simultaneous quench between multi current limiting units. From the analytical and the experimental results, optimal current path and thickness of shunt material was determined for YBCO thin films and shunt resistor between modules was developed. Finally, 14 kV one phase resistive fault current limiter using multi YBCO thin films was constructed and it was possible to get satisfactory test results.