• Title/Summary/Keyword: Power Quality Characteristics

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A Study on the Quality Characteristics of Brown Sauce by the Addition of Red Yeast Rice Powder Roux (홍국파우더 루 첨가량을 달리한 브라운소스의 품질특성에 관한 연구)

  • Kim, Se-Han;Shin, Kyung-Eun;Choi, Soo-Keun;Seo, Yoon-Weon
    • Culinary science and hospitality research
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    • v.18 no.4
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    • pp.222-232
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    • 2012
  • The purpose of this study is Red Yeast Rice power is added to Roux, which is widely used as the liaison to make Brown Sauce, and the chemical and visual characteristics of the Brown Sauce made using the Red Yeast Rice power. Moisture content of Brown Sauce that included the Red Yeast Rice powder. Viscosity and turbidity of the Brown Sauce which included Red Yeast Rice powder. pH, Sugar value, and Reducing Sugar of the Brown Sauce which included Red Yeast Rice powder. The quantitative description analysis of the Brown Sauce showed that the strength of red color intensity, thickness, sour taste, bitter taste and grainess increased as the amount of the added powder increased, while the scorched flavor decreased. The overall result indicates that the addition of the Red Yeast Rice powder influenced the overall acceptability of the sauce, and it appeared that the 30% addition of the powder resulted in the optimal mechanical characteristics and enhancement of the acceptance of the sauce.

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Implementation of a Photovoltaic System Simulator for Interconnecting with Bipolar ±750V DC distribution Grid (바이폴 ±750 직류 배전망 연계용 태양광 발전 시뮬레이터 구현)

  • Kim, Tae-Hoon;Kim, Seok-Woong;Cho, Jin-Tae;Kim, Ju-Yong;Jung, Jae-Seung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.11
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    • pp.1800-1805
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    • 2016
  • The micro-grid designed as bipolar ${\pm}750V$ low-voltage DC power distribution system demonstrated by KEPRI, demands interconnection of a number of small decentralized power source including variable renewable generator. Therefore, variable researches for the influence of interconnection with the bipolar typed DC grid and these variable power sources are required for superior quality of power distribution. Renewable power generation simulators for the bipolar ${\pm}750V$ low-voltage DC power distribution system are necessary for such researches. In this paper, we carry out a research on the photovoltaic simulator that be actually able to interconnect with a bipolar ${\pm}750V$ low-voltage micro-grid. Simulator for this research is not only able to simulate photovoltaic generation according to weather informations and PV modules characteristics, but also contribute to stabilization of bipolar ${\pm}750V$ low-voltage of the system. Therefore, the simulator was designed to develop a system that can situationally respond to variable control algorithms such as the MPPT control, droop control, EMS power control, etc.

Structural relations of convenience food satisfaction and quality of life according to dietary style -Focusing on singles in metropolitan area of Korea-

  • Kim, Boram;Joo, Nami
    • Nutrition Research and Practice
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    • v.8 no.5
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    • pp.564-570
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    • 2014
  • BACKGROUND/OBJECTIVES: Although the issues of singles' dietary style and quality of life are becoming important due to the increasing number of singles with economic power, little research has been conducted to date on singles' use of convenience food and quality of life in relation to their dietary style. Thus, the present study intends to provide basic data to improve the quality of life by determining the current status of the use of convenience food and explicating its relationship with quality of life through analyzing the dietary lifestyles of the singles. SUBJECTS/METHODS: The targets of this study were singles, identified as adults between the ages of 25 and 54, living alone, either legally or in actuality having no partner. A statistical analysis of 208 surveys from Seoul, respectively, was conducted using SPSS12.0 for Windows and SEM using AMOS 5.0 statistics package. RESULTS: The convenience-oriented was shown to have a significant positive effect on convenience food satisfaction. HMR satisfaction was found to have a significant effect on positive psychological satisfaction and the convenience-oriented was found to have a significant negative effect on all aspects of quality of life satisfaction. CONCLUSIONS: There must be persistent development of food industries considering the distinctive characteristics of the lives of singles in order to satisfy their needs and improve the quality of their lives.

Interconnection Capacity Evaluation of Distributed Resources at the Distribution Networks in View of Distribution Protection Coordination (배전계통의 보호협조측면에서 본 분산전원 연계용량 검토)

  • Choi, Joon-Ho;Ro, Kyoung-Soo;Park, Sung-Jun;Song, Kyung-Bin;Yun, Sang-Yun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.3
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    • pp.107-116
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    • 2007
  • The introduction of new renewable energy is going on increase with the second plan of the Korean Government "Technology Development, Utilization and Popularization of New Renewable Energy". In general, it is connected to the power system due to the nature of it's source characteristics but it's interconnection operation impacts on the power system planning and operation. The operation schemes of the existing power distribution system are based on the unidirectional power flow, but unidirectional power flow changes to bidirectional power flow due to the interconnection operation of new renewable energy. It degrade the existing protection coordination system and power quality of the power distribution system. Thus, the technical evaluation process of the interconnection of new renewable energy are necessary. In this paper, the characteristics of the existing automatic recloser and sectionalizer are reviewed and interconnection capacity evaluation method of the DR(distributed resources) in the existing automatic recloser-sectionalizer protective coordination system are proposed.

Characteristics of Particle Growth and Chemical Composition of High Concentrated Ultra Fine Dusts (PM2.5) in the Air around the Power Plant (고농도 초미세먼지 출현 시 발전소 주변 대기 입자 성장 및 화학조성 특성)

  • Suji, Kang;Jinho, Sung;Youngseok, Eom;Sungnam, Chun
    • KEPCO Journal on Electric Power and Energy
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    • v.8 no.2
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    • pp.103-110
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    • 2022
  • Ultrafine Particle number and size distributions were simultaneously measured at rural area around the power plant in Dangjin, South Korea. New Particle formation and growth events were frequently observed during January, 2021 and classified based on their strength and persistence as well as the variation in geometric mean diameter(GMD) on January 12, 21 and 17. In this study, we investigated mechanisms of new particle growth based on measurements using a high resolution time of flight aerosol mass spectrometer(HR-ToF-AMS) and a scanning mobility particle sizer(SMPS). On Event days(Jan 12 and 21), the total average growth rate was found to be 8.46 nm/h~24.76 nm/hr. These growth rate are comparable to those reported for other urban and rural sites in South Korea using different method. Comparing to the Non-Event day(Jan 17), New Particle Growth mostly occurred when solar radiation is peaked and relative humidity is low in daytime, moreover enhanced under the condition of higher precusors, NO2 (39.9 vs 6.2ppb), VOCs(129.5 vs 84.6ppb), NH3(11 vs 4.7ppb). The HR-ToF-AMS PM1.0 composition shows Organic and Ammoniated nitrate were dominant species effected by emission source in domestic. On the other hand, The Fraction of Ammoniated sulfate was calculated to be approximately 16% and 31% when air quality is inflow from China. Longer term studies are needed to help resolve the relative contributions of each precusor species on new particle growth characteristics.

Study on Aging Characteristics of Exploding Foil Initiator (고전압 기폭관의 노화 특성 연구)

  • Kim, Dong-seong;Jang, Seung-gyo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.48 no.8
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    • pp.581-588
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    • 2020
  • The aging characteristics of exploding foil initiator (EFI) are studied. In order to observe the aging characteristics, the main components of the exploding foil initiator were classified and the failure mechanism was defined. The aging characteristics were defined in terms of power and sensitivity, and the accelerated aging test plan was established based on the activation energy calculated by HFC (Heat Flow Calorimetry) and Arrhenius theory. The performance variation was observed using the sensitivity test (Neyer test) and power test (Dent test) for the aged samples. The aging characteristic was observed on the mean exploding point of the sensitivity test, but long-enough life span was predicted considering the related specification.

A Study of the Analysis of Characteristics of Nonlinear Dynamic System on Blood-Flow of Peripheral Blood-Vessel between Diabetic Patients and Control Subjects (당뇨병환자와 정상인의 말초혈관혈류의 비선형적 운동계 분석에 대한 연구)

  • Kim, D.H.;Choi, J.Y.;Yi, S.H.;Go, H.W.;Nam, S.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1996 no.11
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    • pp.363-367
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    • 1996
  • In general, the physiological systems have shown nonlinear complex phenomena. This study analyzes nonlinear characteristics of the flow of peripheral blood vessel dynamics in physiological systems using chaos theory. We performed this study by means of several quantity methods and power spectrum. The quantity methods are a phase space reconstruction and a poincare's map. And the power spectrum method is a conventional linear analysis. Experimental data have been acquired from examining 10 diabetic patients, and 10 control subjects in initial stable state. In acquisition experminetal data, we anlysized the differences of nonlinear characteristics between diabetic group and control group. The results of quality analysis methods showed the flow of peripheral blood vessel had the nonlinear and chaotic characteristics, screening a strange attractor on reconstructed phase space. In conclusion, the flow dynamics of peripheral blood vessel had a chaotic behavior of nonlinear dynamic systems, dynamic system, and differences of characteristic of nonlinear dynamic system.

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Harmonics Analysis for Electric Arc Furnace According to the Operation Condition (전기 아크로 운전 상태에 따른 고조파 해석)

  • Kim, Jae-Chul;Park, Kyung-Ho;Park, Hyun-Teak;Moon, Jong-Fil;Im, Sang-Kug;Son, Hag-Sig
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.18 no.5
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    • pp.118-125
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    • 2004
  • The use of electric arc furnace has been increasing as the steel consumption is increasing and the operation technique of electric arc furnace are developing. But as the use of electric arc furnace is increased, the furnace have produced the adverse effects of power quality: voltage and current harmonics, voltage and current imbalances, low power factor, and voltage flicker. One of the power quality problems, the harmonic have the characteristics of the time-varying and non-linear. This paper analyzed the harmonics for the various operation conditions of electric arc furnace. The power system model with electric arc furnace have been made, and the harmonic's effects on the power system has been analyzed according to the various operating conditions, first melting, second melting, so on. Also, the filter reducing the harmonic components have been designed and its effects on the power system have been examined.

Factors Influencing Quality of Life Elderly Who Live Alone, Depending on Gender (성별에 따른 독거노인의 삶의 질에 영향을 주는 요인)

  • Kwon, Myoungjin
    • Journal of Digital Convergence
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    • v.17 no.1
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    • pp.365-373
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    • 2019
  • This study was conducted to investigate the factors affecting the quality of life of elderly who live alone according to gender. The participants in this study were 959 elderly living alone from a total of 22,948 individuals studied in the 2013-2015 Korean national health and nutrition examination survey. IBM SPSS 23.0 was used to analyze the data. There were significant differences between the two groups in age, level of education, and amount of calorie intake. Economic status, presence of arthritis, presence of restrict activity, subjective health status had an influence on quality of life in men with an explanatory power of 50.5% (p < .001). Presence of back pain, subjective health status, suicidal ideation had an influence on quality of life in women with an explanatory power of 41.4% (p < .001). Therefore, in order to improve the quality of life of elderly living alone, it is necessary to provide appropriate intervention depending on gender.

A Study on Characteristic of Image Quality according to CT Table Height in Computed Tomography (컴퓨터단층촬영 검사 시 테이블 높이에 따른 화질 특성에 관한 연구)

  • Ki-Won Kim;Jung-Whan Min;Sang-Sun Lee;Young-Bong Lee;Ki-Jong Lee;Han-Sol Park;Joo-Young Oh
    • Journal of radiological science and technology
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    • v.46 no.4
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    • pp.295-301
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    • 2023
  • In addition to protocol adjustments during CT examinations, the height of the CT table can also affect image quality. Therefore, this study aimed to investigate the change in image quality depending on the height of the table in brain CT, which accounts for a large proportion of CT examinations, by measuring signal to contrast to noise ratio (CNR) and noise power spectrum (NPS) using the head phantom and evaluating them. The head phantom images were acquired using Philips Brilliance iCT 256. When the image was acquired, the table height was adjusted to 815, 865, 915, 965, 1015, and 1030 mm, respectively, and each scan was performed 3 times for each height. The CNR result showed the highest value at 965 mm, which is the height adjacent to the center of the head phantom. NPS showed the lowest NPS at 915 mm, the center of the head phantom in the low frequency region. From these results, it can be seen that the height of the table in CT examination is closely related to the image quality, and it can be seen the characteristics of image quality according to CT table through quantitative evaluation methods such as CNR and NPS.