• Title/Summary/Keyword: Power factor improvement

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A Study on IT Outsourcing Service Satisfaction Assessment : Focused at System Operation Management Service (정보시스템 아웃소싱 서비스에 대한 만족도 연구 - 시스템 운영관리 서비스를 중심으로 -)

  • Lim, Gyoung Chul;Yeom, Sae Hun
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.7 no.2
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    • pp.173-183
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    • 2011
  • The business is faced with the situation must improve a power in an increasingly competitive environment due to the recent rapid advance in information technology and the opening and expansion of global market, fast technological change, and various customer demand. The rapid change in information technology is having an effect on not only all the processes to develop products, but information contents that is provided for the purpose of customer value, and the appearance of products. In other words, the information technology is being recognized as a very important factor among other factors for companies to enhance their competitiveness. In addition, it is more efficient to focus on key factor to maintain the competitive advantage on the using of information technology by outsourcing information systems, rather than by operating the systems under their own. Since the global financial crisis, the long-term recession has been increasing companies who is ready to adopt outsourcing or adopted already. This study is to understand the environment and unique characteristics of outsourcing services and related industries focusing on information system operation and management in information outsourcing services, and is to set the concept needed through my theory that is connected to the service quality and customer satisfaction. A lot of business wiew the improvement of service quality and ensuring customer satisfaction as the major factors of business growth, and lots of ongoing studies have focused on service management in the Information outsourcing service industry. Yet few studies have ever concentrated on the quality of information system operation management service. This study, moreover, is to define the quality of service related with customer satisfaction from customer's viewpoint, measuring effects on customer satisfaction. The quality of outsourcing service on information system in this study is a great help to companies who are offering information outsourcing service, and company's managers and staffs who outsourcedto specialized company.

The Effect of the Fault Tolerant Capability due to Degradation of the Self-diagnostics Function in the Safety Critical System for Nuclear Power Plants (원자력발전소 안전필수시스템 고장허용능력에 대한 자가진단기능 저하 영향 분석)

  • Hur, Seop;Hwang, In-Koo;Lee, Dong-Young;Choi, Heon-Ho;Kim, Yang-Mo;Lee, Sang-Jeong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.8
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    • pp.1456-1463
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    • 2010
  • The safety critical systems in nuclear power plants should be designed to have a high level of fault tolerant capability because those systems are used for protection or mitigation of the postulated accidents of nuclear reactor. Due to increasing of the system complexity of the digital based system in nuclear fields, the reliability of the digital based systems without an auto-test or a self-diagnostic feature is generally lower than those of analog system. To overcome this problem, additional redundant architectures in each redundant channel and self-diagnostic features are commonly integrated into the digital safety systems. The self diagnostic function is a key factor for increasing fault tolerant capabilities in the digital based safety system. This paper presents an availability and safety evaluation model to analyze the effect to the system's fault tolerant capabilities depending on self-diagnostic features when the loss or erroneous behaviors of self-diagnostic function are expected to occur. The analysis result of the proposed model on the several modules of a safety platform shows that the improvement effect on unavailability of each module has generally become smaller than the result of usage of conventional models and the unavailability itself has changed significantly depending on the characteristics of failures or errors of self-diagnostic function.

Presumed Influence Factors of User Satisfaction of Seoul Digital Industrial Complex using PLS-Regression Model (PLS 회귀분석을 통한 서울디지털산업단지 이용자 만족도 영향요인 규명)

  • Jeong, Gwang-Seop;Park, Gyu-Yong;Lee, Joo-Hyung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.6
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    • pp.3931-3943
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    • 2014
  • Domestic industrial complexes have more loss competitiveness due to their deterioration length and environmental problems. Therefore, it is necessary to suggest the direction of realignment as advanced industrial estates and establish new alternative plans for improving the quality of public and environmental designs as well as reinforcing the competitive power. This study examined the design planning factors affecting the service users' satisfaction in the Seoul Digital Industrial Complex through a PLS regression model. The research result showed that 12 crucial design planning factors out of a total 31 planning factors have a more than 1.0 VIP. In addition, 8 comparatively important planning aspects that were measured between 0.9 and 1.0 were also investigated. These factors were the strategic design planning factors estimating the quantitative priority while enforcing the design improvement project and they should be considered as a useful material for strengthening the competitive power of the Seoul Digital Industrial Complex.

Effects of Pinitol Supplementation and Strength Training on Anaerobic Performance and Status of Energy Substrates in Healthy Young Men

  • Lee, Dae-Taek;Lee, Woon-Yong
    • Nutritional Sciences
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    • v.8 no.3
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    • pp.189-195
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    • 2005
  • To assess the effect of pinitol supplementation and strength training for two weeks on the anaerobic capacity during and after exercise, and improvement of glucose metabolism during the recovery period of muscular fatigue with repeated acute bouts of cycling exercise, a total of 24 healthy young men were recruited and randomly and equally divided into three groups; pinitol supplementation group (PSG), placebo group (PLG), and control group (CON). Using a randomized double-blinded design, subjects in PSG were provided pinitol supplement, consumed orally 1.2 g/day, and participated in the resistance exercise program and cycling exercise for two weeks. Subjects in PLG underwent the same protocol as those in PSG but consumed the same amount of placebo. No supplementation and exercise program was given to CON. Before and after the intervention, all subjects were tested for their anaerobic capacities evaluated by Wingate test twice separated by 30 min. During the test, peak anaerobic power (PP), mean anaerobic power, total work, and fatigue index were evaluated During resting and recovery, blood samples were drawn and plasma pinitol, myo-inositol, chiro-inositol, insulin, free fatty acid, glucose, and lactate levels were analyzed After two weeks, PP and relative PP of the second biking were improved from the first biking in PSG only (p<0.05). No changes were found in all other variables of Wingate test in all groups. No statistical differences between groups and pre- and post-intervention were observed in concentrations of pinitol, myo-inositol, and chiro-inositol, but pinitol concentration was higher during recovery compared to the baseline in all groups and testings (p<0.05). Lactate level during recovery was higher than the resting level, but no other blood parameters were significantly changed. In conclusion, two weeks of pinitol supplementation in conjunction with short duration of anaerobic training in healthy young men did not induce any obvious benefits in terms of anaerobic capacity and energy metabolism Individual and/or population susceptibility may be one factor responsible for adopting pinitol supplementation.

A Study on the Improvement of Coloring in Dye-sensitized Solar Cell (염료감응형 태양전지의 착색 특성 개선 연구)

  • Seo, Hyun-Woong;Kim, Mi-Jeong;Son, Min-Kyu;Lee, Kyoung-Jun;Hong, Ji-Tae;Kim, Hee-Je
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.11a
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    • pp.297-300
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    • 2007
  • In this study, we have attempted a new method to enhance the coloring of dye on the $TiO_2$ surface in the dye sensitized solar cell. In the conventional coloring process in a dye sensitized solar cells, dye is absorbed by the covalent bond between TiO2 and dye molecule while the photo-electrode coated with $TiO_2$ layer is soaked in dye solution for about 12-24 hours. But this process takes long time, so we have researched more effective and faster way than the conventional process by applying electric field. Three kinds of electric power such as direct voltage, alternating voltage and pulse voltage were applied to the transparent conducting oxide during the coloring process. As a result, we achieved improved power, fill factor and efficiency of dye-sensitized solar cell in case of applying direct voltage and pulse voltage. In contrast, alternating voltage tend to reduce the dye adsorption on the $TiO_2$ surface and hence the efficiency. We measured the absorption spectra of dye by UV-VIS spectrophotometer before and after soaking the $TiO_2$ in the dye and found no characteristic change in the dye was observed. In this study, we researched on shortening time of coloring process which spent much time in the whole process.

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A Study on the Volumetric Efficiency Improvement by Variable Induction & Exhaust System in a Turbocharged Diesel Engine (가변 흡.배기시스템에 의한 과급디젤기관의 체적효율 향상에 관한 연구)

  • Kang, H.Y.;Koh, D.K.
    • Journal of Power System Engineering
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    • v.12 no.1
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    • pp.13-19
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    • 2008
  • In this study, a variable induction and exhaust system is applied to turbocharged diesel engine to improve the volumetric efficiency, especially, in a low and transient engine speed range where much of the pollutant matters are expelled out. The volumetric efficiency is known as one of the most important factor which affects significantly engine performance, fuel economy and further emission and noise level. As the torque increase with the engine speed up, the gas flow in an exhaust pipe become pulsating and then has an effect on boost up capacity of air charging into the cylinder and expelling capacity to atmosphere simultaneously. But at a low and idling speed, the pulsation effect was not so significant. Accordingly, resonator was employed to compensate their loss. The variable induction system consists of the secondary pipe, resonator, intercooler, and torque variance were examined with extended operating conditions. In the mean time, for interpretation and well understanding for the phenomena of wave action that arising during intake and exhaust process between turbocharger and variable intake system, the concept of the combined supercharging was introduced. Some of results are depicted which deal with a pressure history during valve events of induction process. Consequently, by the governing of these phase and amplitude of pulsating wave, it enables us to estimate and evaluate for the intake system performance and also, designing stage of the system layout.

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Design and Making of PWM Control-based AC-DC Converter with Full-Bridge Rectifier (전파 정류기를 가지는 PWM 제어 기반의 AC-DC 컨버터 설계 및 제작)

  • Bum-Soo Choi;Sang-Hyeon Kim;Dong-Ki Woo;Min-Ho Lee;Yun-Seok Ko
    • The Journal of the Korea institute of electronic communication sciences
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    • v.18 no.4
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    • pp.617-624
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    • 2023
  • Recently, miniaturization and low power consumption of electronic products and improved efficiency and power factor improvement have become a matter of great interest. In this paper, an AC-DC converter based on PWM control was designed and made. The AC-DC converter is designed with a structure in which one rectifier circuit and one output voltage control circuit are connected in series. The rectifier circuit is a diode-based single phase full-wave current circuit and the output voltage control circuit is a DC-DC conversion circuit based on PWM control. Arduino was used as the main control device for PWM control, and LCD was configured at the output stage so that the control result could be checked. The error between the output voltage displayed on the oscilloscope and LCD and the target output voltage was confirmed through repeated experiments with the test circuit, and the validity of the proposed design methodology was confirmed by showing an error rate of about 5% based on the oscilloscope measurement value.

A Study on the Illumination analysis and Improvement plan for the Public Library Environment (공공도서관의 환경개선을 위한 조도 분석 및 개선 방안에 관한 연구)

  • Kwon, Sun-young
    • Journal of the Korea Convergence Society
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    • v.9 no.8
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    • pp.47-52
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    • 2018
  • Recently, the appearance of the library has changed dramatically more than ever, and it is true that the spatial factor of the library is a big part of this change. The purpose of this study is to establish the criteria for improvement of the illuminance standard of library by comparing analysis of related workd related to illumination, survey, and illuminance related standards of each country. In order to achieve the purpose of research, we measured the illuminance and the users' perceptions of the 14 public libraries in the D region. Finally, the comparison of domestic and international illuminance standards should be improved in the future. As a result of the analysis, it is found that the domestic illumination standard (KSA 3011) needs to be supplemented in accordance with the environment and the case of each country. Also, it is necessary to recognize the importance of differentiation and illuminance according to the age group of users. This study is expected to be a basic research that will raise the interest of the overall illumination improvement and illumination management of the library in the future. In addition, it is expected that it will be a great power for the improvement of the environment including the illumination of the public library in Korea if the interest is maintained based on the revision of the domestic illumination standard in accordance with the revised tendency of overseas recommendation and the continuous research on the future illumination of the library.

An Improvement of Stochastic Feature Extraction for Robust Speech Recognition (강인한 음성인식을 위한 통계적 특징벡터 추출방법의 개선)

  • 김회린;고진석
    • The Journal of the Acoustical Society of Korea
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    • v.23 no.2
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    • pp.180-186
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    • 2004
  • The presence of noise in speech signals degrades the performance of recognition systems in which there are mismatches between the training and test environments. To make a speech recognizer robust, it is necessary to compensate these mismatches. In this paper, we studied about an improvement of stochastic feature extraction based on band-SNR for robust speech recognition. At first, we proposed a modified version of the multi-band spectral subtraction (MSS) method which adjusts the subtraction level of noise spectrum according to band-SNR. In the proposed method referred as M-MSS, a noise normalization factor was newly introduced to finely control the over-estimation factor depending on the band-SNR. Also, we modified the architecture of the stochastic feature extraction (SFE) method. We could get a better performance when the spectral subtraction was applied in the power spectrum domain than in the mel-scale domain. This method is denoted as M-SFE. Last, we applied the M-MSS method to the modified stochastic feature extraction structure, which is denoted as the MMSS-MSFE method. The proposed methods were evaluated on isolated word recognition under various noise environments. The average error rates of the M-MSS, M-SFE, and MMSS-MSFE methods over the ordinary spectral subtraction (SS) method were reduced by 18.6%, 15.1%, and 33.9%, respectively. From these results, we can conclude that the proposed methods provide good candidates for robust feature extraction in the noisy speech recognition.

BER performance analysis of successive interference cancellation(SIC) algorithm for W-CDMA HSDPA receiver (W-CDMA HSDPA수신기의 직렬간섭제거 알고리즘의 오류율 성능해석)

  • Koo Je-Gil
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.41 no.1
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    • pp.13-22
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    • 2004
  • This paper drives the exact expression of bit error rate(BER) performance for successive interference cancellation(SIC) algorithm against multipath interference components in a high-speed downlink packet access(HSDPA) system of W-CDMA downlink and the BER performance is evaluated by numerical analysis. Numerical results showed that the average BER performance is rapidly saturated in terms of increasing the number of multipath and is revealed significant improvement for improvement Processing gain(PG). For example, the average BER Performance of the SIC algorithm is superior to the performance of conventional scheme by more than 7dB and 1.4dB for processing gain PG=54 and 128 under the two-path channel and average BER=$1.0{\times}10^{-3}$, respectively. This results also indicated that the average BER saturation is occurred at nearly one weight factor which is assigned to pilot and data channels. Likewise, the average BER performance is greatly degraded due to increasing the interference power in proportional to the number of multipath with increasing multicode K. And the smaller multipath fading channel gain is arrived later, the more the average BER performance is improved. The results of performance analysis in this paper indicated that the multipath interference cancellation is required to improve the BER performance in a HSDPA system under multicode for high-speed packet transmission, low spreading factor, and multipath fading channel.