• Title/Summary/Keyword: Rating Frequency Weight

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Utility Interactive Inverter with High-frequency Link for Photovoltaic Power System (고주파링크 방식을 이용한 계통연계형 태양광발전시스템)

  • Jung, Y.S.;Yu, G.W.;Lee, S.H.
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.1050-1052
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    • 2000
  • An investigation into power conditioners that interface with photovoltaic array and utilities has been completed. The rating for this investigation is residential system (3-5kW) that interface with a 220V single phase utility connection. As the result of this investigation. a 3kW high frequency PWM IGBT inverter feeding a high frequency isolation transformer with a sinusoidal current wave was selected. The output of the transformer rectified with a diode bridge rectifier four IGBT, used as 60Hz switched, reverse the polarity of the rectified current on every other half cycle of the utility voltage. Even though the high frequency link system used more power semiconductors, a net size, weight, and parts cost saving result compared to the other systems due to elimination of 60Hz transformer.

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High-Frequency DC Link Inverter for Grid-connected PV System (계통연계형 태양광발전시스템을 위한 고주파 DC 링크 인버터)

  • Jung Young-Seok;Yu Gwon-Jong
    • Proceedings of the KIPE Conference
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    • 2001.07a
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    • pp.46-49
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    • 2001
  • An investigation into power conditioners that interface with photovoltaic array and utilities has been completed. The rating for this investigation is residential system(3-5kVA) that interface with a 220V single phase utility connection. As the result of this investigation, a 3kVA high frequency PWM IGBT inverter feeding a high frequency isolation transformer with a sinusoidal current wave was selected. The output of the transformer rectified with a diode bridge rectifier. four IGBT, used as 60Hz switched, reverse the polarity of the rectified current on every other half cycle of the utility voltage. Even though the high frequency link system used more power semiconductors, a net size, weight, and parts cost saving result compared to the other systems due to elimination of 60Hz transformer.

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Testing the Validity and Reliability of FIPS(Face Interval Pain Scale) with Children림s Pain from Intramuscular Injection (환아에게 적용한 얼굴그림 동통척도의 타당도 및 신뢰도 연구)

  • 김주희;김분한
    • Journal of Korean Academy of Nursing
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    • v.24 no.3
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    • pp.461-472
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    • 1994
  • The main purpose of this study was to test the validity and reliability of FIPS as an assessment tool for pain in children. The subject were 81 children whose ages ranged from 3 to 14 years old who were experiencing pain from an intramuscular injection. 40 were being seen in a local primary hospital and 41 in a university hospital. The data were collected in two settings at a 6 month interval, the first was on Nov. 5th 1991 in a local clinic by one doctor, the second was on May 1st. 1992 in a university hospital by two nurse. McGrath's(1985) face interval cards and weight box scale which is a numeral scale that contains from one to five boxes of cards were used as measures. To analyze the subject's ability to use the face scale and weight box scale, statistical frequency was employed. To determine the difference in the rated pain in-tensity on the face interval scale and the weight box, Pearson correlation coefficient and t-test were employed. To compare the difference in the rated pain intensity of the face interval scale and the weight box scale according to subject's general characteristics, X²-test was employed. The findings were as follows : 1. The subject's ages were from 3 to 14 with a mean age of 8.3 years old. There were 54(66.7%) male children and 27(33.3%) female children. 2. The number of subjects who correctly displayed cards ranging from none to severe pain was 66(81.5%) and the number who correctly compared two cards 3 times was 73(90.l%). 3. Correlation coefficients between each level card of the FIPS and WBS (Weight Box Scale) were r=.52∼.80 P<0.01. 4. There was no statistical difference in rating of the intensity on the FIPS and WBS.(t=1.12∼l.02, P<0.22∼0.45). 5. The differences in rating pain intensity according to the children's general characteristics were re-lated to age(X²=8.94, P<0.05), but not to sex (X²=0.23, P=0.80).

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Investigation of the heavy-weight floor impact sound field in a testing building with bearing wall structure (벽식구조 표준시험동에서 중량충격음장에 관한 연구)

  • Yoo, Seung-Yup;Lee, Sin-Young;Jeon, Jin-Yong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.969-973
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    • 2007
  • The heavy-weight floor impact sound field of the receiving room in a testing building with bearing wall structure was investigated using bang machine and impact ball. The sound field was investigated through the impact sound pressure level distribution by the field measurement and computational analysis. Predicted sound field using the computational analysis agree with measurement result in the low frequency band. Result shows that standard deviations of the single number rating value are about 2dB in each impact source. Particularly, impact sound pressure level at 120cm height in 63Hz octave band was 5dB lower than spatial averaging value. It was found that receiving positions in the ministry of construction and transportation notice should be reconsidered.

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Performance Improvement of Overpass Bridge by Weight Reduction (고가교 경량화에 따른 성능개선)

  • Kim, Sung Bae;Nam, Sang Hyeok;Kim, Jang-Ho Jay
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.2
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    • pp.51-60
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    • 2011
  • In this study, structural safety capacity analysis of the overpass railway bridge between Konkuk Univ. and Guui station railroad has been performed. The overpass is expected to have suffered durability reduction by deterioration. The weight reduction of the overpass has been implemented to prevent further durability reduction and to improve performance capacity. To reduce the weight, 3 procedures of replacing concrete soundproofing wall to light-weight soundproofing wall, replacing gravel ballast to concrete ballast, and reducing the weight of trough have been performed. The analysis of static/dynamic behaviors and improved capacity of the light-weighted overpass bridge has been performed. The structural safety verification of the improved structure has been implemented by using rating factors of load carrying capacity of PSC I girder. The results have shown that the deflection has been reduced by 2.6mm and tensile strength has been improved by 1.07MPa, which indicate that the structural capacity has effectively been improved. Also, the natural frequency has improved by approximately 30% where vibration reduction and dynamic behavior improvement have been achieved. Moreover, in the rating factor evaluation based on analysis and test results, an improvement from 1.82 to 1.93 has been observed. Therefore, weight reduction method for the overpass is effective considering overall results.

Deviation of sound pressure level in receiving room according to the heavy-weight floor impact sources and it's positions (중량 바닥충격음 충격원의 종류 및 위치에 따른 수음실 음압레벨 변화)

  • Ju, Mun Ki;Han, Myung Ho;Oh, Yang Ki
    • KIEAE Journal
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    • v.9 no.4
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    • pp.23-28
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    • 2009
  • Standard sound source currently used in heavy-weight floor impact sounds that cause many social problems has excessive low-frequency energy within a range from 63 Hz to 125 Hz, and is difficult to evaluate and measure. To solve these problems, studies are widely performed using a new impact source, the impact ball. In this study, the sound fields in a receiving room were compared and analyzed according to the current impact source, the bang machine, and the impact ball. And deviation of sound pressure level according to the impact source positions were compared. In case of impact ball, the sound pressure level was lower at 63 Hz and below and higher at 125 Hz and above. The same trend was observed at the low-frequency range on the horizontal and vertical planes, regardless of the type of the impact source, which showed the influence of the room mode. There was a problem with the variations in the sound pressure level according to the size or shape of the receiving room. And it also shows that change of source positions may effect the single number rating scheme.

A Design of HPPS(Hybrid Preference Prediction System) for Customer-Tailored Service (고객 맞춤 서비스를 위한 HPPS(Hybrid Preference Prediction System) 설계)

  • Jeong, Eun-Hee;Lee, Byung-Kwan
    • Journal of Korea Multimedia Society
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    • v.14 no.11
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    • pp.1467-1477
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    • 2011
  • This paper proposes a HPPS(Hybrid Preference Prediction System) design using the analysis of user profile and of the similarity among users precisely to predict the preference for custom-tailored service. Contrary to the existing NBCFA(Neighborhood Based Collaborative Filtering Algorithm), this paper is designed using these following rules. First, if there is no neighbor's commodity rating value in a preference prediction formula, this formula uses the rating average value for a commodity. Second, this formula reflects the weighting value through the analysis of a user's characteristics. Finally, when the nearest neighbor is selected, we consider the similarity, the commodity rating, and the rating frequency. Therefore, the first and second preference prediction formula made HPPS improve the precision by 97.24%, and the nearest neighbor selection method made HPPS improve the precision by 75%, compared with the existing NBCFA.

Application of Finite Element Method to Floor Impact Vibration Analysis in the Apartment Buildings (공동주택의 바닥 충격 진동 해석을 위한 유한요소법 응용)

  • Seo, Sang-Ho;Jeon, Jin-Yong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.387-390
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    • 2005
  • Finite element method was applied to the vibration analysis of concrete slab system in apartment building. To save the time and cost the 2 dimensional finite element model was proposed. At first, experimental results show that sound peak components to influence the overall level and the rating of floor impact sound insulation were coincident with natural frequencies of the reinforced concrete slab. Second, there is linear relationship between the impact sound pressure level and vibration acceleration level. Third, 2 dimensional finite element model was enough to analyze the vibration analysis of floor structure system.

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A study on the Improvement of Facility Layout in Locomotive Maintenance Workshop (철도차량 정비공장의 설비배치 개선에 관한 연구)

  • 이상설;안도만;강희정
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.22 no.49
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    • pp.89-98
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    • 1999
  • The objective of this study is to develop an improved algorithm for layout problems. Computerized facility layout program was also applied to solve the layout problem in locomotive maintenance workshop. The current facility layout is structured in the large space without considerations of many variable factors. For this reason, effectiveness of layout results in loss on effective space utility. This study is to develop an algorithm in the consideration of importance weight and desirable shape of specific department in the computerized layout planning and quantitative relationship rating between each department was used. Standard process duration of locomotive maintenance workshop was used to select the main activities of locomotive maintenance work. This study could generate more efficient facility layout design to reduce the number of movement frequency and travel distance in maintenance workshop.

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A Case Report on Chronic Intestinal Pseudo-obstruction Presenting as Unspecified Abdominal Pain in an Adult (만성 거짓 장폐쇄로 진단한 상세불명의 복통 환자 증례 보고)

  • Ha, Yu-bin;Jang, Han-sol;Shin, Gil-cho
    • The Journal of Internal Korean Medicine
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    • v.42 no.5
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    • pp.1094-1101
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    • 2021
  • Objectives: This study examined a case of chronic intestinal pseudo-obstruction (CIPO) in an adult with unspecified abdominal pain.Methods: The patient was treated with herbal medicine, acupuncture, and moxa. Treatment progress was evaluated by follow-up monitoring of the intensity, frequency, and duration (in hours) of abdominal pain and body weight. Results: The average abdominal pain level on the Numerical Rating Scale (NRS) and its incidence decreased. The duration of pain was 15 hours maximum and 2.5 hours minimum. The body weight repeatedly increased and decreased but increased overall. Despite no remarkable findings from X-rays, air-fluid levels and coil-shaped folds of the small bowel were observed. Conclusions: Korean medical treatment based on a dialectic effectively relieved chronic abdominal pain and suspected CIPO-a disease that requires continuous management and therapeutic intervention.