• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1623-1627
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• 2002

If the ambient temperature rises in AC PDP, some of the discharged cells arc turned off because of the addressing failure. Particularly, the addressing failure at the last scan line is more serious than at the first scan line. The failure is accompanied with delay of the address discharge and reduction of total charge involved. In order to compensate this kind of misfiling, the progressively increasing address voltage waveform is used instead of constant one. In this method, we found that the total charge and address time at the last scan line are similar to those of the first line. As a result, we can have stable discharge without misfiring even at the high ambient temperature.

• Journal of Korea Society of Digital Industry and Information Management
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• v.15 no.4
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• pp.1-8
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• 2019

In this paper, we study the BESS of a standalone hybrid street light. The proposed BESS proposed a BESS with the function of efficiently charging irregularly generated power from two or more generators. AC generated by wind power is converted to DC using an AC / DC converter and then to a voltage that can charge the battery through the DC / DC converter. The lack of voltage and current, which is a disadvantage of the MPPT method used in solar power generation, is compensated by the DC value of wind power generation. The compensation method is to convert the DC generated from solar power into a voltage suitable for charging the battery through a DC / DC converter, and then connect the DC generated in wind power in parallel to compensate for the insufficient current to charge the battery in a short time. Allow this to begin. By securing the maximum charging time, the usage time of the stand-alone hybrid street light is huge. Experimental results show that the battery has a short charging time and can be efficiently applied to battery-dependent standalone hybrid street lights.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.379-381
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• 1994

Volume holograms recorded in photorefractive materials can find important applications in optical memories and optical computing systems. One problem with a photorefractive hologram is that it gets erased by the readout light. Nondestructive readout can be achieved by hologram fixing, and several fixing methods have been reported. Fixing is accomplished by thermally activated motion of an unknown ionic defect, which neutralizes the electronic space-charge patterns. At room temperature the ionic patterns are stabilized. When the electrons are partially redistributed by light, a net space-charge pattern appears, and tile fixed hologram can be read out. In this paper, theoretical modeling and some experimental results are presented for thermal fixing of volume phase holograms in photorefractive $LiNbO_3$:Fe. Thermal fixing can be done during or after recording and depends on fixing temperature ($100{\sim}200^{\circ}C$ range) and grating length. Fixed Slating can be erased completely at the temperature over $300^{\circ}C$. Theoretical modeling shows weil the compensation of electronic Slating by ionic grating and is in good agreement with experimental results. In experiments the dependence of thermal fixing on temperatures and grating lengths is investigated.

• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.189-194
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• 2024

This paper presents a radiation-hardened-by-design preamplifier that utilizes a self-compensation technique with a charge-sensitive amplifier (CSA) and replica for total ionizing dose (TID) effects. The CSA consists of an operational amplifier (OPAMP) with a 6-bit binary weighted current source (BWCS) and feedback network. The replica circuit is utilized to compensate for the TID effects of the CSA. Two comparators can detect the operating point of the replica OPAMP and generate appropriate signals to control the switches of the BWCS. The proposed preamplifier was fabricated using a general-purpose complementary metal-oxide-silicon field effect transistor 0.18 ㎛ process and verified through a test up to 230 kGy (SiO₂) at a rate of 10.46 kGy (SiO₂)/h. The code of the BWCS control circuit varied with the total radiation dose. During the verification test, the initial value of the digital code was 39, and a final value of 30 was observed. Furthermore, the preamplifier output exhibited a maximum variation error of 2.39%, while the maximum rise-time error was 1.96%. A minimum signal-to-noise ratio of 49.64 dB was measured.

• Journal of Environmental Policy
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• v.8 no.2
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• pp.25-61
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• 2009

These days, environmental policies have changed from being command and control systems toward economic incentive systems, with various incentives having been established by OECD countries. In Korea, many environmental charges have been established in order to diminish activities which damage natural resources. Among them, the Ecosystem Conservation Cooperation Charge and the Replacement Charge for Forest Resources Creation are considered to be representative environmental charges. These charges, along with a few others, were designed to encourage efforts to protect natural resources. The charges include a number of different features, utilize varying methods, and altered ranges of jurisdiction. However, the charges may pose serious inequity problems in terms of their estimated values and their conditions of reduction and exemption. For instance, although the Ecosystem Conservation Cooperation Charge is a primary charge applied to natural resource damage, the charge does not fully secure its original objectives due to its low levy and limited range of provisions. Moreover, the Replacement Charge for Forest Resources Creation has been criticized because of similar reduction and exemption provisions. Therefore, this study analyzes the inequity problems associated with the charges and proposes solutions. First of all, the Ecosystem Conservation Cooperation Charge should be redesigned in such a way that it reflects the substantial value of natural resource damage through either abrogate or increased maximum limits of the charge. With regard to the Replacement Charge for Forest Resources Creation, the cases and ranges of reduction and exemption provisions should be narrowed. Finally, the charges collected should be expended in conformity with their original objectives, and their expenditure should be restricted to either restoration activities or activities directly related to compensation and mitigation of damaged natural resources.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.12 s.354
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• pp.74-80
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• 2006

This work presents a novel architecture of phase locked loop (PLL) with the current compensating scheme to improve phase noise performance. The proposed PLL has two Charge Pump (CP), main-CP (MCP) and sub-CP (SCP). The smaller SCP current with same time duration but opposite direction of UP/DN MCP current is injected to the loop filter (LF). It suppress the voltage fluctuation of LF. In result, it improves phase noise characteristic. The Proposed PLL has been fabricated with 0.35fm 3.3V CMOS process. Measured phase noise at 1-MHz offset is -103dBc/Hz resulting in a minimum 3dBc/Hz phase noise improvement compared to the conventional PLL.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.10
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• pp.1935-1940
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• 2016

This paper proposes a phase-locked loop (PLL) to minimize the loop filter output voltage fluctuation by using a comparator including RC time constant circuits. The voltage variation of loop filter is inputted to RC time constant circuits which have two RC time constants, large and small. While a small RC time constant circuit quickly conveys the output voltage variation of loop filter, a large RC time constant circuit conveys slowly the output voltage variation of loop filter and its output looks like constant voltage. The output signal of the comparator controls the sub charge pump and reduces the input voltage variation of voltage-controlled oscillator (VCO). Therefore, the proposed PLL generates a phase noise reduced signal. It has been designed with a 1.8V supply voltage, 0.18um multi - metal and multi - poly layer CMOS process and proved by Hspice simulation.

• Journal of the Korean Society of Radiology
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• v.16 no.5
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• pp.639-647
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• 2022

This study analyzed the job characteristics of radiological technologists in charge of ultrasound examinations in the Yeongnam region. The measuring tool used in the study was a questionnaire, and the subjects were radiological technologists in charge of ultrasound examination at medical institutions located in the Yeongnam region from August 01 to November 30, 2021. In consideration of the COVID-19 situation, statistical analysis was performed using the SPSS/PC Ver 18.0 program using e-mail and SNS in a non-face-to-face manner with 158 questionnaires. As a result of analyzing the job characteristics of the radiological technologists in charge of ultrasound examination, the job satisfaction was 3.24±0.61. In the effect of job characteristic factors on job satisfaction, professional position, self-esteem, and trust relationship formation were found to be higher than the average of 3.0. However, as the dissatisfaction factor, compensation and appropriateness of work were cited. Therefore, in order to improve the job characteristics and satisfaction level of radiological technologists in charge of ultrasound examinations, it is necessary to do their best to improve the appropriate work environment of medical institutions and to continuously secure professionalism of radiological technologists in charge of ultrasound examinations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2358-2370
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• 2010

This research aims to empirically analyze the factors that affect the success of technology marketing by Korean universities. The total of 207 universities which successfully made technology transfers from 2006 to 2008 was examined to test the nine hypotheses. For the purpose of testing the hypotheses, technology infrastructure (research costs and the number of SCIE papers), the compensation system for the patents (application and registration), the number of patents (application and registration), TLO staff (the number of people in charge of technology transfer and the job experience in industries), the compensation system for technology transfers (researchers and contributors), and attitudes of university management and industries were analyzed with structural equation methods to figure out their effects on the revenues of technology transfer. The results of this research are summarized as follows. First, technology infrastructures of universities were found to have positive effects on securing patents. As the university research costs in the field of science and technology are increases, the research capabilities are enhanced and this a larger number of researchers are conducted. Second, this research shows that compensation systems for patent application and registration in universities have motivated researchers to take out patents for the outputs of their research. Third, the number of patents universities possess was found to have a positive effect on technology transfer. An increase in the number of patents universities possess implies an increase in the diversity and excellence of the target technologies for transfer. Fourth, the number of patents universities possess turned out to have a positive effect on TLO staff. The number of experts in charge of technology transfer including technology dealers, valuation analysis and patent attorneys should be increased as target technologies for transfer increase according to the increase of patents possessed. Because the technologies are transferee from universities to businesses, businesses (job) experience of TLO staff in industries are also important. This research is meaningful because it has identified the factors affecting the results of technology transfer by employing structural equation methods. In particular, an official governmental survey data for the academic-industrial cooperation were analyzed systematically in terms of technology infrastructure, compensation systems related to patents, the number of patents, TLO staff, compensation systems for technology transfer, and attitudes of university management and industries. All these facts might could differentiate this study from the previous studies.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.453-454
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• 2016

The ESS(Energy Storage System) connected with distributed generation is drawing attention due to improving the quality load leveling, peak shaving for enhancing reliability of the power grid. The grid-connected inverter makes frequency adjustment to the active power's charge discharge according to the load variation. In addition, the inverter is possible to act as a reactive power compensation device to eliminate harmonic operates as power factor change inhibiting, anti-transient voltage fluctuation, active filter. In this paper, we propose a design method of igbt stack considering the reactive power supply capacity to improve the quality and reliability of the inverter. Moreover, the grid-connected inverter considering the four-quadrant rated operation designed stack and verified the feasibility of the design through a thermal analysis.