• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.8
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• pp.1654-1660
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• 2004

In this paper, we describes the design and implementation of LonWorks communication module for distributed intelligent control using LonWorks technology of Echelon. LonWorks communication module can be divided hardware and firmware. First, hardwares is divided into microcontroller attaching sensors and LonWorks components for working together control network and data network. Hardwares are consisted of neuron chip, microcontroller, transceiver, LONCard. Second, operating firmware is realized with neuron C using NodeBulider 3.0 development tool. Produced and implemented LonWorks communication module is pretested using LTM-10A, Gizmo 4 I/O board, parallel I/O Interface. For field test, microcontroller module part is tested by HyperTerminal, communication procedure in data network is certified by transmitting and receiving short message using LonMaker for Windows tool. Herewith, LON technology is based on network communication technique using LonWorks.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.5
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• pp.577-584
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• 2015

A photovoltaic (PV) system generates electricity by installing a solar energy array; therefore, the photovoltaic system can be easily exposed to external factors, which include environmental factors such as temperature, humidity, and radiation. These factors-as well as shading, in particular-lead to power degradation. When there is an output loss in the solar cell of a PV module package, the output loss is partly controlled by the bypass diode. As solar cells become highly efficient, the characteristics of series resistance and parallel resistance improve, and the characteristics of reverse voltage change. A bypass diode is connected in parallel to the string that is connected in series to the PV module. Ideally, the bypass diode operates when the voltage is -0.6[V] around. This study examines the bypass diode operating time for different types of crystalline solar cells. It compares the reverse voltage characteristics between the single solar cell and polycrystalline solar cell. Special modules were produced for the experiment. The shading rate of the solar cell in the specially made solar energy module was raised by 5% each time to confirm that the bypass diode was operating. The operation of the bypass diode is affected not only by the reverse voltage but also by the forward bias. This tendency was verified as the number of strings increased.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.189-192
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• 2004

A LNA module, integrated microwave assemblies (IMAs) were developed for use in Ka-band Satellite Communication Satellite Payload that operates in the frequency range of 29,6 ${\~}$ 30.0GHz. The module will be placed directly behind their respective antenna feed horns to minimize the required waveguide and system noise figure impact. Two MMIC LNA Chips were used in the module design. The measured result shows that the module has 32dB gain and 2.4dB NF performance. The module size is 51m ${\times}$ 36m ${\times}$ 22 and the mass is 92g. The Noise Figure performance is the best result of currently available modules for satellite payload operating in the same frequency range. The module will be assembled using space-qualified process and tested for space qualification.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.11
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• pp.1280-1287
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• 2012

The 3.2~6.5 GHz wideband YTO(YIG Tuned Oscillator) module is designed, fabricated and measured. To improve the phase noise characteristic of the YTO module, offset PLL(Phase Locked Loop) structure with sampling mixer is applied. This YTO module is composed of sampling mixer, phase detector, loop filter, current driver, and YTO. The phase noise of the fabricated YTO module is measured as -100 dBc/Hz at 10 kHz offset frequency, which approximates the predicted result at the center frequency of 4.5 GHz. This YTO module presents over 10 dB improved phase noise compared to conventional PLL module from operating frequency.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.8
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• pp.177-184
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• 2019

Recently, electric power usages and peak loads from buildings are increasing due to higher outdoor air temperatures and/or abnormal climate during the summer period. As one of the eco-friendly measures, a renewable energy system has been received much attention. Particularly, interest on a photovoltaic (PV) system using solar energy has been rapidly increasing in a building sector due to its broad applicability. In using the PV system, one of important factors is the PV efficiency. The normal PV efficiency is determined based on the STC(Standard Test Condition) and the NOCT(Nominal Operating Cell Temperature) performance test. However, the actual PV efficiency is affected by the temperature change at the module surface. Especially, higher module temperatures generally reduce the PV efficiency, and it leads to less power generation from the PV system. Therefore, the analysis of the relation between the module temperature and PV efficiency is required to evaluate the PV performance during the summer period. This study investigates existing algorithms for calculating module surface temperatures and analyzes resultant errors with the algorithms by comparing the measured module temperatures.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.6_1
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• pp.927-939
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• 2022

This study was conducted to develop a Web-GIS based monitoring module of smart city that can effectively respond, manage and improve situation in all stages of illegal dumping management on a city scale. First, five technologies were set for the core technical elements of the module configuration. Five core technical elements are as follows; video screening technology based on motion vector analysis, human behavior detection based on intelligent video analytics technology, mobile app for receiving civil complaints about illegal dumping, illegal dumping risk model and street cleanliness map, Web-GIS based situation monitoring technology. The development contents and results for each set of core technical elements were evaluated. Finally, a Web-GIS based 'illegal dumping monitoring module' was proposed. It is possible to collect and analyze city data at the local government level through operating the proposed module. Based on this, it is able to effectively detect illegal dumpers at relatively low cost and identify the tendency of illegal dumping by systematically managing habitual occurrence areas. In the future, it is expected to be developed in the form of an add-on module of the smart city integration platform operated by local governments to ensure interoperability and scalability.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.11
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• pp.2285-2291
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• 2011

In this paper, H.264 high profile intra frame encoder, which integrates intra prediction, context-based adaptive variable length coding(CAVLC), and DDR2 memory control module, is proposed. The designed encoder can be operated in 440 cycle for one-macroblock. In order to verify the encoder function, we developed the reference C from JM 13.2 and verified the developed hardware using test vector generated by reference C. The designed encoder is verified in the FPGA (field programmable gate array) with operating frequency of 200 MHz for DMA (direct memory access), operating frequency of 50 MHz of Encoder module, and 25 MHz for VIM(video input module). The number of LUT is 43099, which is about 20 % of Virtex 5 XC5VLX330.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.130-136
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• 2014

This paper reviews the research on silicon based phased array system operating from microwave to millimeter wave frequencies. First, the design of phase shifter using CMOS technology is presented. The passive phase shifter is applied to the transmit/receive module from one to 16 channel in a single chip. The 35 GHz 4-element T/R module consumes less than 200 mW both transmit and receive modes. The architecture can extend to 16-channel operating at 44 GHz, thereby improving transmit power and linearity. The Ku-band 2-antenna 4-element receiver was developed using active phase shifter based on vector sum method. It is important to minimize coupling between beams because the chip contains four independent beams. The method of coupling is presented and verified.

• Journal of Power Electronics
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• v.4 no.2
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• pp.77-86
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• 2004

This paper presents a novel three-phase power module bridge type auxiliary resonant AC link snubber for the three-phase voltage-fed sinwave soft switching PWM inverter operating under specific instantaneous space voltage vector modulation. The operating principle of this resonant snubber is described for current source load model during one switching period, along with its design approach based on the simulation data. The performance evaluations of space vector modulation three-phase sinewave soft switching inverter with a new three-phase active auxiliary resonant AC link snubber are discussed as compared with those of three-phase voltage source-fed sinewave hard switching PWM inverter with a standard space voltage vector modulation strategy. The power loss analysis and conventional efficiency estimation of three-phase soft switching PWM inverter using ICBT modules are carried out including all the conduction power losses based upon the measured v-i characteristics of IGBT and its antiparallel diode as well as their switching losses.

• Journal of Biosystems Engineering
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• v.24 no.3
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• pp.267-274
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• 1999

An internet and network based software and related interface have been developed, which can remotely control and manage an on-site operating system. Developed software modules were composed of two parts: monitoring/management modules and control/diagnosis modules were developed for the network status, warehouse, production and selling status. Modules of control with diagnosis were developed for the on-site operating system and interface. Each module was integrated and the whole modules have been tested with an automatic mushroom grading/sorting system which was built in a laboratory. Developed software modules worked successfully without any uncommon situations such as system down caused by the software or data transfer error. Each software module was developed independently in order to apply easily to other existing on-site systems such as rice processing centers, fruit and vegetable sorting, packaging and distribution centers scattered over the country.