• Title/Summary/Keyword: Load correlation

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A study on the Limitation presumption of Maximum Weightlifting load of Snatch three dimention motion analysis (3D 인상 동작에서 최대중량부하의 극한계치 추정에 관한 연구)

  • 이창민;서국웅;김용재
    • Proceedings of the ESK Conference
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    • 1997.10a
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    • pp.168-176
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    • 1997
  • The purpose of this study is to know load for each human body's knee joint to endure load efficiently, when weight lifter pulls suitable bar in the each weight lifting level. To use the difference of load and correlation between men and women, the conclusion of this stduy is to find parameters to conduct maximum limitation of maximum load to search maximum limitation. The moment of each joint in the lower area was to have a much difference between group of the turunk in the first step. It decreased rapidly until decent and greatly pulled in the second step. Neuromusclar moment increased suddenly in the decrease phase. This phenomenon resulted from shock-absorbing function to sbsorb a load from bar.

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Short-term Load Forecasting of Using Data refine for Temperature Characteristics at Jeju Island (온도특성에 대한 데이터 정제를 이용한 제주도의 단기 전력수요 예측)

  • Kim, Ki-Su;Song, Kyung-Bin
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2008.10a
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    • pp.225-228
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    • 2008
  • The electricity supply and demand to be stable to a system link increase of the variance power supply and operation are requested in jeju Island electricity system. A short-term Load forecasting which uses the characteristic of the Load is essential consequently. We use the interrelationship of the electricity Load and change of a summertime temperature and data refining in the paper. We presented a short-term Load forecasting algorithm of jeju Island and used the correlation coefficient to the criteria of the refining. We used each temperature area data to be refined and forecasted a short-term Load to an exponential smoothing method.

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Power Load Density Analysis considering Structure and Characteristics of Subway Stations (지하철 역사의 구조 및 특성을 고려한 동력부하밀도 분석)

  • Jung, Hyun-Ki;Cha, Kwang-Seok
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.912-920
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    • 2006
  • The purpose of this study is to present the design standard for load density in subway station. From the data of electric equipment capacity and electric power consumption for 43 subway stations, current levels of the load density and excess capacity factor were surveyed and analyzed, In addition mean value, standard deviation, maximum value, median value and correlation coefficient were evaluated through excel program. Also it was carried out the regression analysis. The estimation method of load density and design criterion were studied. As a result, load density in this thesis have been proposed : 51.3 $[VA/m^2]$ on the general power load can be a standard value for subway station.

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The preliminary study of developing strong corrugated box board against aggravated service condition(I) (환경변화에 강한 골판지 개발을 위한 기초연구(제1보))

  • 서영범;오영순
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.30 no.1
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    • pp.29-43
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    • 1998
  • This study was to investigate the effect of .compressive load and cyclic humidity(2$0^{\circ}C$, 65% and 90% RH) on the physical and mechanical properties of corrugated board. Corrugated boards in the study were under compressive load and under cyclic humidity, and their properties were compared to those without load. Results were summarized as follows ; 1 Statistically significant correlation was shown between the ring crush of the boards and the compressive strength of cylinder specimen made from the boards. So we could study the compressive behavior of board with cylinder specimen. 2. The boards under the compressive load increased their moisture content and thickness much more than those without load both in constant and in cyclic RH. 3. The compressive and tensile strength of board samples were inversely and closely proportional to the sheet moisture content regardless of their load and humidity history. 4. The moisture content did not show any significant proportionality to the change of burst strength of boards within this experiment. 5. Board reconditioning in standard condition led to the recovery of the strength loss that had occurred under various load and humidity condition. 6. The handsheets prepared from the boards that had experienced compressive load and cyclic humidity, and those with no-load and 65% RH did not show any significant difference in strength properties. No physical damage or load-carrying properties of the wood fiber were observed by the compressive load and cyclic humidity history.

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Accuracy of combination rules and individual effect correlation: MDOF vs SDOF systems

  • Reyes-Salazar, Alfredo;Valenzuela-Beltran, Federico;de, Leon-Escobedo, David;Bojorquez, Eden;Lopez-Barraza, Arturo
    • Steel and Composite Structures
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    • v.12 no.4
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    • pp.353-379
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    • 2012
  • The accuracy of the 30% and SRSS rules, commonly used to estimate the combined response of structures, and some related issues, are studied. For complex systems and earthquake loading, the principal components give the maximum seismic response. Both rules underestimate the axial load by about 10% and the COV of the underestimation is about 20%. Both rules overestimate the base shear by about 10%. The uncertainty in the estimation is much larger for axial load than for base shear, and, for axial load, it is much larger for inelastic than for elastic behavior. The effect of individual components may be highly correlated, not only for normal components, but also for totally uncorrelated components. The rules are not always inaccurate for large values of correlation coefficients of the individual effects, and small values of such coefficients are not always related to an accurate estimation of the response. Only for perfectly uncorrelated harmonic excitations and elastic analysis of SDOF systems, the individual effects of the components are uncorrelated and the rules accurately estimate the combined response. In the general case, the level of underestimation or overestimation depends on the degree of correlation of the components, the type of structural system, the response parameter, the location of the structural member and the level of structural deformation. The codes should be more specific regarding the application of these rules. If the percentage rule is used for MDOF systems and earthquake loading, at least a value of 45% should be used for the combination factor.

Evaluation of J-R Curve for Aluminum 5083 Alloy Weldment by Load Ratio Analysis (Load Ratio 해석에 의한 알루미늄 5083 합금 용접부의 J-R곡선 평가)

  • 윤한기;김연겸
    • Journal of Welding and Joining
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    • v.15 no.4
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    • pp.178-186
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    • 1997
  • The purpose of this study is to evaluate the J-R curve characteristics for the 5083 aluminum alloy weldment by the load ratio analysis. The results of the load ratio analysis are compared with those of the J-R curve which are obtained by the ASTM unloading compliance method. The crack length calculated by the load ratio analysis is agrees well with the measured final crack length. The slope of the exponential J-R curve estimated by the load ratio analysis is slightly smaller than that by the ASTM unloading compliance method. The exponential correlation of the J-R curve for the 5083 aluminum alloy base metal by the load ratio analysis is J = 93.88 ${\Delta}{\alpha}^{0.375}$. That for the weld metal and HAZ is J = 69.87 ${\Delta}{\alpha}^{0.389}$ and J = 70.59 ${\Delta}{\alpha}^{0.359}$ respectively. The J-R curve obtained by the ASTM unloading compliance method is overpredicted and should be offsetted due to the initial negative crack. On the other hand, the load ratio analysis method can evaluate the J-R curve by only load displacement curve without particular crack measurement equipment.

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A Study on Modeling of Users a Load Usage Pattern in Home Energy Management System Using a Copula Function and the Application (Copula 함수를 이용한 HEMS 내 전력소비자의 부하 사용패턴 모델링 및 그 적용에 관한 연구)

  • Shin, Je-Seok;Kim, Jin-O
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.1
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    • pp.16-22
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    • 2016
  • This paper addresses the load usage scheduling in the HEMS for residential power consumers. The HEMS would lead the residential users to change their power usage, so as to minimize the cost in response to external information such as a time-varying electricity price, the outside temperature. However, there may be a consumer's inconvenience in the change of the power usage. In order to improve this, it is required to understand the pattern of load usage according to the external information. Therefore, this paper suggests a methodology to model the load usage pattern, which classifies home appliances according to external information affecting the load usage and models the usage pattern for each appliance based on a copula function representing the correlation between variables. The modeled pattern would be reflected as a constraint condition for an optimal load usage scheduling problem in HEMS. To explain an application of the methodology, a case study is performed on an electrical water heater (EWH) and an optimal load usage scheduling for EHW is performed based on the branch-and-bound method. From the case study, it is shown that the load usage pattern can contribute to an efficient power consumption.

A Study on Solar Radiation Analysis and Saving Elements of Heating Load according to the Location and Type of Housing in Multi-family Apartments (공동주택 주동형태별 세대위치에 따른 일사분석 및 난방부하 절감요소에 관한 연구)

  • Kim, Soo-Jeong;Park, Doo-Yong;Kim, Kang-Soo
    • KIEAE Journal
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    • v.13 no.1
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    • pp.47-55
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    • 2013
  • This study aims to evaluate the correlation between vertical solar radiation and the level of heating load according to the location and type of housing in multi-family apartments. This study shows that heating load is related with factors such as wall loss, window loss, ventilation loss and solar radiation gain. The heating load increases in the order of the middle floors, the highest floors and the lowest floors. The lowest and the highest floors are the most vulnerable floors, and it should be as emphasized as the middle floors. The heating load saving proposal contains 52 Alt. that shows heating load savings from min. 4% to max. 49%. The goal is to reduce the heating load of the highest and the lowest floors to the level of the middle floors. The result showed that there are 3 Alt. for the lowest floors and 16 Alt. for the highest floors as the heating load saving proposal. This study suggests integrated application to compose saving elements of heating load. so it could be utilized as a data for the construction of passive houses.

The Distribution Characteristics of Organic Matters in the Contaminated Tributaries of Han River Region (한강권역 우심지류 하천의 유기물 분포 특성)

  • Kim, Ho-Sub;Park, Yun-Hee;Kim, Yong-Sam;Kim, Sang-Yong
    • Journal of Korean Society on Water Environment
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    • v.34 no.5
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    • pp.494-502
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    • 2018
  • The purpose of this study was to understand distribution characteristics of organic matters through concentration of $BOD_5$, $COD_{Mn}$ and TOC in 31 streams in Han River region, and to establish the relationship among organic matter concentration, and discharge load and flow rate. Concentration of $BOD_5$ and TOC in 22 streams were above IV grade except 9, and the average 80.9 % of total organic matter (by TOC) accounted for dissolved organic type. Correlation among organic matter parameters were higher ($r^2$ > 0.78) and the relationship between TOC and $COD_{Mn}$ concentration was higher than $BOD_5$. Ratio of biodegradable organic matter/total organic matter in the 31 streams was estimated at 41.4 % with $BOD_5$ oxidation rate, and 78.0 % with $BOD_5/COD_{Mn}$ concentration ratio. Ratio of $NBOD/BOD_5$ concentration in four sites with $BOD_5/COD_{Mn}$ concentration ratio exceeding 1 ranged from 54.5 % ~ 79.3 %. Among 979 flow rate data measured at 31 streams, 87 % of measured data was below 0.1 cms and increased water pollution under low flow conditions. Correlation between $BOD_5$ concentration and $BOD_5$ discharge load in the watershed was low, and it was revealed that several streams have more $BOD_5$ delivery load than $BOD_5$ discharge load. Results suggest that many biodegradable forms of organic matter are being introduced into the stream from pollutant sources in the watershed.

Field monitoring of the train-induced hanger vibration in a high-speed railway steel arch bridge

  • Ding, Youliang;An, Yonghui;Wang, Chao
    • Smart Structures and Systems
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    • v.17 no.6
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    • pp.1107-1127
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    • 2016
  • Studies on dynamic characteristics of the hanger vibration using field monitoring data are important for the design and evaluation of high-speed railway truss arch bridges. This paper presents an analysis of the hanger's dynamic displacement responses based on field monitoring of Dashengguan Yangtze River Bridge, which is a high-speed railway truss arch bridge with the longest span throughout the world. The three vibration parameters, i.e., dynamic displacement amplitude, dynamic load factor and vibration amplitude, are selected to investigate the hanger's vibration characteristics in each railway load case including the probability statistical characteristics and coupled vibration characteristics. The influences of carriageway and carriage number on the hanger's vibration characteristics are further investigated. The results indicate that: (1) All the eight railway load cases can be successfully identified according to the relationship of responses from strain sensors and accelerometers in the structural health monitoring system. (2) The hanger's three vibration parameters in each load case in the longitudinal and transverse directions have obvious probabilistic characteristics. However, they fall into different distribution functions. (3) There is good correlation between the hanger's longitudinal/transverse dynamic displacement and the main girder's transverse dynamic displacement in each load case, and their relationships are shown in the hysteresis curves. (4) Influences of the carriageway and carriage number on the hanger's three parameters are different in both longitudinal and transverse directions; while the influence on any of the three parameters presents an obvious statistical trend. The present paper lays a good foundation for the further analysis of train-induced hanger vibration and control.