• Title/Summary/Keyword: Saturation

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Case Study on Collection Saturation of Public Library (공공도서관 장서의 포화에 관한 사례 연구)

  • Kim, Hong-Ryul
    • Journal of Korean Library and Information Science Society
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    • v.50 no.3
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    • pp.49-69
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    • 2019
  • The purpose of this study is to measure the saturation of the collection in public library and to propose a solution to this problem. In order to conduct this study, one local government was selected to measure the collection saturation status of each library and to clarify the cause of collection saturation. Based on the research results derived from this study, the public library in Korea measures the degree of collection saturation and recognizes the seriousness of collection saturation, and suggests the task of identifying the cause of collection saturation and solving it.

Analysis of Saturation Flow Rate on Interrupted Flow During Rainfall (강우시 단속류 포화교통류율 변화 분석)

  • Kim, Bongseok;Roh, Chang-Gyun;Son, Bongsoo
    • Journal of Korean Society of Transportation
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    • v.33 no.1
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    • pp.90-99
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    • 2015
  • The climate of Korea has clear rainy and dry season due to seasonal wind. In general, The rainy season in Korea is from early summer through to early fall. And precipitation accounted for more than half of the total annual rainfall in this period. This study is aiming to analysis of variation in saturation flow rate at signalized intersection during rainfall. The range of spatial is urban signalized intersections in Seoul and temporal is rainfall or ideal condition in daylight. Traffic data are collected through CCTV of Seoul Metropolitan Police Agency, and on-site video recordings directly. Weather condition data are collected from the Korea Meteorological Administration. In addition, the value of saturation headway and saturation flow rate, in rainfall condition, are derived through video frame analysis. As a results of analysis, decrease of saturation flow rate and increase of saturation headway during rainfall were confirmed by comparison with non-rainfall. The higher rainfall rate is, the more decreased saturation flow rate at the intersections. Rainfall rate is divided three area by the results of statistical test, and saturation flow rate decrease 7%, 17%, 21%, respectively.

The Formation of Transient Saturation Zone and the Subsurface flow on the Steep Hillslope by Rains (降雨에 의한 急斜面의 일시적인 飽和帶形成과 중간류 流出)

  • An, Jung-Gi
    • Journal of Korea Water Resources Association
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    • v.31 no.2
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    • pp.167-176
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    • 1998
  • On steep hillslopes, saturation zone formations and subsurface flows were monitored through the observation systems of observation wells, tensiometers and trenches. By the 103 mm rain which had fallen on the hillslope with dry soil moisture, the saturation zone began to be formed at the top of hillslope during the rain and developed to be formed within a few hours after the end of rain on all hillslope. Subsurface water outflowed mainly from the soil profile of 0-40 cm depth, but did not outflow from the one of 40-80 cm depth. This saturation zone seemed to be formed by partially saturation of soil. This resulted for two reasons. Firstly, the saturation zone was formed by a smaller amount of rain than that required. Secondly the soil at a certain depth below the water table was unsaturated. Saturation zones formed by pre-rains responded rapidly to rains and subsurface water outflowed mainly from the soil profile of 40-80 cm depth simultaneously with the rising of the water level. The rates of subsurface discharge from the soil profile of 40-80 cm depth to the precipitation were related to the antecedent precipitation although the maximum water levels of saturation zone formed by four rains were similar.

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High Dynamic Range Imaging Using Inverted Local Patterns with Saturation Compensation (포화도 보상의 반전 지역 패턴을 이용한 HDR 영상화)

  • Kwon, Oh Seol
    • Journal of Broadcast Engineering
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    • v.23 no.5
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    • pp.714-717
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    • 2018
  • This paper presents a method of HDR imaging with adaptive saturation compensation for brightness change. The saturation of HDR images were lighten on dark region because conventional HDR methods have focused on brightness change. Therefore, the proposed HDR method compensates saturation adaptively according to brightness change. For experiments of several images, the proposed algorithm is superior to conventional HDR methods qualitatively and quantitatively in terms of color saturation.

Analytical Study Considering Both Core Loss Resistance and Magnetic Cross Saturation of Interior Permanent Magnet Synchronous Motors

  • Kim, Young-Kyoun
    • Journal of Magnetics
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    • v.17 no.4
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    • pp.280-284
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    • 2012
  • This paper presents a method for evaluating interior permanent magnet synchronous motor (IPMSM) performance over the entire operation region. Using a d-q axis equivalent circuit model consisting of motor parameters such as the permanent magnetic flux, copper resistance, core loss resistance, and d-q axis inductance, a conventional mathematical model of an IPMSM has been developed. It is well understood that in IPMSMs, magnetic operating conditions cause cross saturation and that the iron loss resistance - upon which core losses depend - changes according to the motor speed; for the sake of convenience, however, d-q axis machine models usually neglect the influence of magnetic cross saturation and assume that the iron loss resistance is constant. This paper proposes an analysis method based on considering a magnetic cross saturation and estimating a core loss resistance that changes with the operating conditions and speed. The proposed method is then verified by means of a comparison between the computed and the experimental results.

Force Reflection Control with a Speed Saturation Compensation Scheme for Telemanipulators (원격조작기의 속도포화 보상 힘반영 제어)

  • Ahn, Sung-Ho;Yoon, Ji-Sup;Lee, Sang-Jeong
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.10
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    • pp.894-902
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    • 2000
  • This paper proposes a force reflection control method with a speed saturation compensation scheme for the slave manipulators having a speed saturation due to the high reduction ratio joints. When speed saturation is generated, the proposed force reflection control method not only shows an anti-windup feature in controlling the slave manipulator but also makes the master manipulator move slowly using the force reflection caused by saturation. In this way, the position of the slave manipulator tracks the reference position regardless of speed saturation. The experimental results show that the proposed control method provides excellent performance.

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Shear Characteristics of Weathered Granite Soils for Degree of Weathering and Saturation (화강토의 풍화도와 포화도에 따른 전단특성)

  • Song, Chang-Seob;Jang, Wong-Hee
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.3 no.3
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    • pp.1-7
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    • 2000
  • The aim of the work described in this paper is to study the shear characteristics of the weathered granite soil. To this end, a series of consolidated undrained triaxial compression tests are carried out to investigate the shear parameters-cohesion and internal friction angle for the degree of saturation and degree of weathering. From the results, it is found that the shear parameters of weathered granite soil are influenced on the degree of saturation, degree of weathering and disturbance. Especially, internal friction angle is more influenced on the upper factors than cohesion. And shear parameters are more acted on the degree of saturation than the degree of weathering in the test range. It is, therefore, recommended that must be considered the conditions of granite soil-degree of saturation, degree of weathering and disturbance etc-in case of the calculation of bearing capacity, stability analysis and other designs with shear parameters.

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A Busbar Current Differential Relay with a Compensating Algorithm (보상 알고리즘을 적용한 모선보호용 전류차동 계전기)

  • 강용철;윤재성
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.53 no.4
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    • pp.214-220
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    • 2004
  • This paper describes a busbar current differential relay in conjunction with a current transformer(CT) compensating algorithm irrespective of the level of the remanent flux. The compensating algorithm detects the start of first saturation if the third-difference function of the current exceeds the threshold; it estimates the core flux at the first saturation start by inserting the negative value of the third-difference function of the current into the magnetization curve; thereafter, it calculates the core flux during the fault and compensates the distorted current using the magnetization curve. The algorithm estimates the correct secondary current irrespective of the level of the remanent flux and needs no saturation point of the magnetization curve. The proposed relay can improve not only security of the relay on an external fault with CT saturation but sensitivity of the relay on an internal fault; the relay can improve the operating speed on n internal fault with CT saturation. This paper concludes by implementing the relay into a digital signal processor based prototype relay.

Reduction of Transconduce in Saturation Region of Short Channel LDD(Lightly Doped Drain) NMOSFETs (짤은 채널 LDD(Lightly doped Drain)NMOSFET의 포화영역 Transconductance 감소)

  • 이명복;이정일;강광남
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.1
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    • pp.74-80
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    • 1990
  • The transconductance of short channel LDD MOSFETs in the saturation region (high Vd)has shown different characteristics from that of conventional device. The transconductance in saturation regime of short channel LDD MOSFETs is reduced from maximum value at higher gate voltage. This decline is analyzed as the velocity saturation effects of carrier at LDD region but accurate analytical expressions for the drain current Idsat and the transconductance Gmsat in the saturation regime are still not in existence. Recently the drain current dependence of parasitic source resistance Rs has been modeled from the velocity saturation of carriers in LDD region. In this study, we approximate that Rmsat that Rs is linearly dependent on the applied gate voltage. Analytical expressions for Idsat and Gmsat obtained from this approximation show the same general behavior as experimental results of short channel LDD NMOSFETs.

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An Adaptive Color Enhancement Algorithm using the Preferred Color Reconstruction (선호색 보정을 이용한 화질 향상 알고리즘)

  • Yang, Kyoung-Ok;Hwang, Bo-Hyun;Lee, Seung-Jun;Yun, Jong-Ho;Chon, Myung-Ryul
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.57 no.1
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    • pp.22-29
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    • 2008
  • In this paper, we propose an adaptive color enhancement algorithm. It is used for the flat panel displays (FPDs) such as LCD, PDP, and so on. The proposed algorithm consists of an adaptive linear approximation CDF(Cumulative Density Function) algorithm and an adaptive saturation enhancement algorithm. The one is for contrast enhancement which prevents an image from the distortion by luminance transient of an input image. The other is the algorithm which improves the saturation without the contour artifact and over-saturation, whose problems are generated during the enhancing saturation. In addition, it allows to achieve the high quality image using the saturation enhancement method for a preferred color of original image. Visual test and standard deviation of their histograms have been applied to evaluate the resultant output images of the proposed algorithm.