• 제목/요약/키워드: contribution ratio

검색결과 682건 처리시간 0.023초

공작기계 주축의 요소별 정동적 강성기여율 및 개선에 관한 연구 (The Contribution of Spindle Parts to Static, Dynamic Stiffness and Design Improvement)

  • 이찬홍;박천홍;이후상
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 추계학술대회 논문집
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    • pp.985-988
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    • 2002
  • The Spindle-]fearing System is very important unit for geometrical accuracy in machine tools. To improve effectively the weak point of spindle system, it is necessary that the contribution ratio of spindle core parts to static and dynamic stiffness is clarified. In this paper, static contribution ratio of core parts is calculated by overlapping static deformation of basic spindle design with one flexible parts. The dynamic contribution ratio for natural frequency and dynamic deformation at spindle end is obtained by calculating correlation between original and basic spindle deformation, by curve fitting with regressive method. It is proved the validity of estimation result is correct.

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부산지역 봄철 주중/주말의 PM10 중 이온성분의 화학적 조성 (Weekday/weekend Chemical Characteristics of Water-Soluble Components of PM10 at Busan in Springtime)

  • 전병일
    • 한국환경과학회지
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    • 제24권6호
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    • pp.785-792
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    • 2015
  • This study investigates weekday/weekend characteristics of $PM_{10}$ concentration and chemical composition of water-soluble ions in Busan in the spring of 2013. Contribution rate of water-soluble ions to PM10 concentration in weekday/weekend were 41.5% and 38.5%, respectively. Contribution rate of SO_4{^{2-}}$ to total ion mass in weekday/weekend were 30.4% and 33.8%, respectively. Contribution rate of total inorganic water-soluble ions in PM10 in weekday/weekend were 42.2% and 39.1% (mean 41.4%), respectively. $[NO_3{^-}/SO_4{^{2-}}]$ ratio in weekday/weekend were 1.01 and 0.97(mean 0.99), respectively, which indicated that weekday ratio was higher. Contribution rate of sea salts and $Cl^-/Na^+$ ratio in PM10 in weekday/weekend were 8.1% and 7.6%, 0.37% and 0.41%, respectively. This research will help understand chemical composition of water-soluble ions during the weekday/weekend and will be able to measure the contribution level of artificial anthropogenic source on urban air.

배수구역의 유달오염부하량이 소양호 유역에 미치는 기여율 평가 (Evaluation of the Contribution Ratio that the Pollution Loads of the Drainage Areas Affect Soyang-lake)

  • 박수진
    • 한국산학기술학회논문지
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    • 제15권8호
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    • pp.5363-5368
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    • 2014
  • 본 논문은 소양호 유역을 대상으로 배수구역의 유달오염부하량을 산정하여 유황 및 계절변화에 따른 소양호 유역에 미치는 기여율을 평가 하였다. 유황변화에 따른 배수구역의 기여율을 보면 인북천 유역의 SS와 T-P 항목이 평수량 이상과 저수량 기간에서 46%와 51%의 기여율을 T-P는 평수량 49.5%, 저수량 기간은 48.5%의 기여율을 보였다. 다음으로 계절 변화에 따른 기여율을 관찰한 결과, 인북천 SS 항목이 전 계절 동안 39.6%에서 44.3%를 T-P는 53.8%로 다른 배수구역에 비하여 높은 기여율을 보였다. T-N은 전 계절에서 내린천 유역이 39.6%에서 44.3%의 기여율을 보였다. 전체적으로 인북천 유역의 SS와 T-P 항목, 내린천의 T-N이 소양호 유역의 오염물질 유출에 높은 기여율을 보였다.

Concrete contribution to initial shear strength of RC hollow bridge columns

  • Kim, Ick-Hyun;Sun, Chang-Ho;Shin, Myoungsu
    • Structural Engineering and Mechanics
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    • 제41권1호
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    • pp.43-65
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    • 2012
  • The primary objective of this study was to identify concrete contribution to the initial shear strength of reinforced concrete (RC) hollow columns under lateral loading. Seven large-scale RC rectangular hollow column specimens were tested under monotonic or cyclic lateral loads. The most important design parameter was column length-to-depth aspect ratio ranging between 1.5 and 3.0, and the other test variables included web area ratio, hollow section ratio, and loading history. The tests showed that the initial shear strength reduced in a linear pattern as the column aspect ratio increased, and one specimen tested under cyclic loading achieved approximately 83% of the shear strength of the companion specimen under monotonic loading. Also, several pioneering shear models proposed around the world, all of which were mainly based on tests for columns with solid sections, were reviewed and compared with the test results of this study, for their possible applications to columns with hollow sections. After all, an empirical equation was proposed for concrete contribution to the initial shear strength of RC hollow columns based on fundamental mechanics and the test results.

Super High Contrast Ratio of TN mode TFT- LCD by Taguchi Design

  • Huang, Y.J.;Chao, Andy;Huang, K.T.;Hung, Y.W.;Yu, C.H.;Wu, H.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.1652-1655
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    • 2008
  • A new high contrast LCD structure for TN mode TFT-LCD, of which the contrast ratio is 1.2 times hi gher than that of the conventional one, has been developed. The contrast ratio of TFT-LCD display can be improved by some modified materials, which like as polarizer, liquid crystal, color filter and light enhancement film. In order to know which condition can get the major contribution for the upgrade of the contrast ratio, we used Taguchi method and analyzed the contribution ratio for each composition and succeed to build up the formula of contrast ratio. From this study, we could achieve the highest CR value as 1200:1 of TN mod e TFT-LCD nowadays.

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감속단 백래시 기여율 변화에 따른 2단 기어 감속서보 시스템의 주파수 응답 특성 (Frequency Response Characteristics of Two-Staged Gear Reduction Servo System According to the Backlash Contribution Ratio Variation of Each Gear Reduction Stage)

  • 백주현;홍성민;양태석;김수현;곽윤근
    • 한국정밀공학회지
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    • 제19권5호
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    • pp.103-109
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    • 2002
  • The paper investigates the change of frequency response characteristics on two-stage gear reduction servo system according to the variation of backlash amount of each gear reduction stage, under the condition that the backlash of total system is constant. It is shown that the frequency response characteristics of the system heavily depend on the contribution ratio which is defined as a ratio of the first backlash amount to the total backlash. It is also found that there is an optimal backlash combination to maximize the bandwidth of two-stage gear reduction servo system when the allowable total backlash is determined.

Molecular Weight Distribution of Liquid Phase AN and Solid Phase Polymer in Precipitation Polymerization of AN By Changing Solution Composition and Temperature

  • Liu, Weiwei;Zhang, Shuangkun;Wang, Jing;Ryu, Seung Kon;Jin, Ri-Guang
    • Carbon letters
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    • 제13권3호
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    • pp.133-138
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    • 2012
  • According to kinetic mechanisms, liquid phase polymerization and solid phase polymerization are different in acrylonitrile (AN) polymerization, and so the relationship between the contribution ratio and molecular weight distribution (MWD) was obtained through theoretic analysis. The precipitation homopolymerization of AN was carried out in a mixture solution of dimethyl sulfoxide (DMSO) and water at $50{\sim}65^{\circ}C$ using ${\alpha}$,${\alpha}^{\prime}$-azobisisobutyronitrile as an initiator. The contribution ratio decreased and approached 0; the MWD also decreased and approached 2 with the increase of the $H_2O$/DMSO ratio from 10/90 to 90/10. The experimental data were found to coincide well with the theoretical equation derived from the mechanisms.

Moment ratio considering composite beam action for steel special moment frames

  • Sang Whan Han;Soo Ik Cho;Taeo Kim;Kihak Lee
    • Steel and Composite Structures
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    • 제47권4호
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    • pp.489-502
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    • 2023
  • The strong column-weak beam (SCWB) moment ratio is specified in AISC 341 to prevent an abrupt column sway in steel special moment frames (SMFs) during earthquakes. Even when the SCWB requirement is satisfied for an SMF, a column-sway can develop in the SMF. This is because the contribution of the composite beam action developed in the concrete floor slab and its supporting beams was not included while calculating the SCWB moment ratio. In this study, we developed a new method for calculating the SCWB moment ratio that included the contribution of composite beam action. We evaluated the seismic collapse performance of the SMFs considering various risk categories and building heights. We demonstrated that the collapse performance of the SMFs was significantly improved by using the proposed SCWB equation that also satisfied the target performance specified in ASCE 7.

우리나라 부부의 가계에 대한 경제적 기여도 평가를 위한 총노동시간 및 노동분담률 분석 (Total Labor Tune and The Ratio of Labor Division for Estimating of Economic Contribution to Household on Korean Married Couples)

  • 윤소영
    • 대한가정학회지
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    • 제40권8호
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    • pp.23-36
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    • 2002
  • The purpose of this study is to analyze the actual condition of labor during the marriage by estimating the total labor-time of husband and wife and to prove the contribution of labor-time to household. The statistical life-time research data of Bureau of Statistics were used to prove the overwork of wives compared with husbands during the marriage. The result of the study can help to prove the wife's contribution of labor-time to household.

Mode identifiability of a multi-span cable-stayed bridge utilizing stabilization diagram and singular values

  • Goi, Y.;Kim, C.W.
    • Smart Structures and Systems
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    • 제17권3호
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    • pp.391-411
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    • 2016
  • This study investigates the mode identifiability of a multi-span cable-stayed bridge in terms of a benchmark study using stabilization diagrams of a system model identified using stochastic subspace identification (SSI). Cumulative contribution ratios (CCRs) estimated from singular values of system models under different wind conditions were also considered. Observations revealed that wind speed might influence the mode identifiability of a specific mode of a cable-stayed bridge. Moreover the cumulative contribution ratio showed that the time histories monitored during strong winds, such as those of a typhoon, can be modeled with less system order than under weak winds. The blind data Acc 1 and Acc 2 were categorized as data obtained under a typhoon. Blind data Acc 3 and Acc 4 were categorized as data obtained under wind conditions of critical wind speeds around 7.5 m/s. Finally, blind data Acc 5 and Acc 6 were categorized as data measured under weak wind conditions.