• Title/Summary/Keyword: Drop Out

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Low Drop-Out (LDO) Voltage Regulator with Improved Power Supply Rejection

  • Jang, Ho-Joon;Roh, Yong-Seong;Moon, Young-Jin;Park, Jeong-Pyo;Yoo, Chang-Sik
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.12 no.3
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    • pp.313-319
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    • 2012
  • The power supply rejection (PSR) of low drop-out (LDO) voltage regulator is improved by employing an error amplifier (EA) which is configured so the power supply noise be cancelled at the output. The LDO regulator is implemented in a 0.13-${\mu}m$ standard CMOS technology. The external supply voltage level is 1.2-V and the output is 1.0-V while the load current can range from 0-mA to 50-mA. The power supply rejection is 46-dB, 49-dB, and 38-dB at DC, 2-MHz, and 10-MHz, respectively. The quiescent current consumption is 65-${\mu}A$.

Pressure Drop and Flow-Induced Vibration Test for the HANARO Non-instrumented Irradiation Test Rig of Annular Fuel Pellet (환형소결체 하나로 조사시험용 무계장 리그의 차압 및 유동유발 진동시험)

  • Lee, Kang-Hee;Kim, Dae-Ho;Bang, Jae-Gun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.281-286
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    • 2007
  • Needs of fuel's performance evaluation for the dual-cooled fuel pellet (annular shape) necessitate the irradiation test in the test reactor. Irradiation test rig for the HARARO reactor, which is a special-purposed equipment used for material, irradiation and creep test, must satisfy the operational requirement on the hydraulic characteristics and structural integrity. In this paper, pressure drop and flow-induced vibration test for the newly developed non-instrumented test rig were carried out using FIVPET as a out-pile evaluation test. The test results show that the new test rig satisfy the HANARO operational requirement with sufficient margin. The spectral response characteristics of the flow-induced vibration of the test rid were also discussed.

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An Adaptive Drop Marker for Edge Routers in DiffServ Networks

  • Hur, Kyeong
    • Journal of information and communication convergence engineering
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    • v.9 no.4
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    • pp.411-419
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    • 2011
  • In this paper, we propose an Adaptive Regulating Drop (ARD) marker, as a novel dropping strategy at the ingressive edge router, to improve TCP fairness in assured services (ASs) without a decrease in the link utilization. To drop packets pertinently, the ARD marker adaptively changes a Temporary Permitted Rate (TPR) for aggregate TCP flows. The TPR is set larger than the current input IN packet rate of aggregate TCP flows while inversely proportional to the measured input OUT packet rate. To reduce the excessive use of greedy TCP flows by notifying droppings of their IN packets constantly to them without a decrease in the link utilization, the ARD marker performs random early fair remarking of their excessive IN packets to OUT packets at the aggregate flow level according to the TPR. In addition, an aggregate dropper is combined to drop some excessive IN packets fairly and constantly according to the TPR. Thus, the throughput of a TCP flow no more depends on only the sporadic and unfair OUT packet droppings at the RIO buffer in the core router. Then, the ARD marker regulates the packet transmission rate of each TCP flow to the contract rate by increasing TCP fairness, without a decrease in the link utilization.

Differentiated Services in Wired Ship Area Networks (선박 내 유선망에서 차등화 서비스 기술)

  • Jeon, Hwang-jong;Kim, Seong-pyo;Park, Jin-gwan;Oh, Ju-seong;Lee, Seung-Beom;Hur, Kyeong;Jeong, Min-a;Lee, Seong Ro
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.10a
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    • pp.165-167
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    • 2014
  • In this paper, an packet drop technique is proposed to outperform the previous RIO (RED In and Out) drop mechanism for DiffServ in ship area networks. the proposed packet drop technique does not manage the individual flows and divides them into several flow groups according to a criterion. And it guarantees the fairness between individual flows in the same QoS class through the group-based control. In simulation results of the proposed packet drop technique, the link utilization decreases than RIO. But it guarantees more data rates to DiffServ flows passing multiple bottleneck links.

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Influence of Velocity on Pressure Drop of Flowing Ice Slurry in Elbow and its continued Inclined Tube (곡관과 연속된 경사관 내에서 유동하는 아이스슬러리의 압력손실에 미치는 유속의 영향)

  • Park Ki-Won;Kim Kyu-Mok
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.17 no.7
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    • pp.635-641
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    • 2005
  • This study experimented to understand the effects of transporting ice slurry through elbow and inclined tube. And at this experiment it used propylene glycol-water solution and a diameter of about 2mm ice particle. The experiments were carried out under various conditions, with velocity of water solution at the entry ranging from 1.0 to 3.5 w/s and elbows and inclined tubes of 4 kinds angle with $30^{\circ},\;45^{\circ},\;90^{\circ}\;and\;180^{\circ}$. The pressure drop between the tube entry and exit were measured. According to angle of bending, the highest pressure drop was measured at $30^{\circ}$ elbow and the lowest pressure drop was measured at $90^{\circ}$ elbow, and there are only a little differences of pressure drop between $45^{\circ}$ elbow and $180^{\circ}$ elbow. According to angle of inclined tube, the highest pressure drop was measured at $90^{\circ}$ inclined tube and the pressure drop at $45^{\circ},\;30^{\circ},\;180^{\circ}$ inclined tubes were lower successively. The lowest pressure drop in elbows and inclined tubes was measured at velocity of $2.0\~2.5$ m/s and concentration of $10\;wt\%$.

Study on Pressure Drop and Condensation Heat Transfer Characteristics of R-404A in Brazed Plate Heat Exchanger (R-404A를 사용한 용접형 판형 열교환기의 압력강하 및 응축 열전달특성에 관한 연구)

  • 권오갑;전창덕;강종식;이진호
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.3
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    • pp.174-183
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    • 2001
  • Experimental study has been carried out on the characteristics of pressure drop and heat transfer of brazed plate heat exchangers using R-404A. Data are presented for the following range of variables: the mass flux ($20~80kg/m^2s$), chevron angle($20^{circ}C,\;35^{circ}C,\;45^{circ}C$) and inlet pressure of he refrigerant (1.4 and 1.6 MPa). for both subcooled and tow-phase flow, as chevron angle increases, pressure drop and heat transfer coefficient decrease. Condensation hat transfer coefficient and pressure drop was compared with the previously proposed correlations. Among them, Traviss correlation agreed with experimental results within -35~82% for heat transfer coefficient and -73~93% for pressure drop.

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Pressure Drop and Refrigerant-Entrainment Characteristics of the Eliminators used in Absorption Chillers (흡수식 냉동기용 엘리미네이터의 압력손실 및 액적유입 특성)

  • 정시영;류진상;이상수;이정주
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.2
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    • pp.109-115
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    • 2003
  • The performance of two vertical-blade eliminators (V1, V2) and two horizontal-blade ones (H1, H2) for absorption chillers were tested in terms of pressure drop and refrigerant entrainment. The test was carried out using a wind tunnel with a cross section of 300 mm$\times$300 mm. The pressure drop of four eliminators tested was found to be in the rage of 1.0~2.7mm $H_2O$ at the face velocity of 2m/s. In the refrigerant entrainment test the vertical-blade eliminators showed much better performance than the horizontal-blade ones. The horizontal-blade eliminators showed satisfactory results at the air velocity of 2m/s but exceeded the limit value at 3 m/s. Since the cooling capacity of a machine is lowered by about 2.5% at the pressure drop of 1 m $H_2O$, more researches are required to reduce the pressure drop in the eliminator.

A numerical analysis and experimental study on the prediction of spray characteristics (분무특성 예측을 위한 이론적 접근과 실험적 연구)

  • Yoon, S.J.;Cho, D.J.
    • Journal of ILASS-Korea
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    • v.3 no.2
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    • pp.1-13
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    • 1998
  • A theoretical and experimental study was carried out to predict the drop size distribution of the pressure swirl atomizer. Various analytical methods using the Kelvin-Helmholtz instability theory were tried to examine the wave growth on cylindrical liquid sheets. Cylinderical liquid sheets were extended to the case with the conical sheets. Perturbations due to tangential motion as well as longitudinal one were taken into account. And it was assumed that the breakup occurs when amplitude ratio exceeds exp(12), drop sizes were predicted only by theoretical approach. Drop size distribution was obtained by using maximum entropy formalism. Seven constraints in the form of the definition of mean diameter were used in this formulation in order to avoid the difficulties of estimating source terms. In this study $D_{10}$ only was introduced into the formulation as a constraint. The predicted drop size and drop size distribution agreed well with the measured data.

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A Study on Pressure Drop Characteristics of Refrigerant in Heat Exchanger for Automobile (자동차용 열교환기 냉매의 압력 강하 특성에 관한 연구)

  • 임태우;박종운
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.2
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    • pp.119-125
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    • 2003
  • An experiment study on pressure drop was carried out for both an adiabatic and a diabatic two-phase flow with pure refrigerants R134a and Rl23 and their mixtures as test fluids in a uniformly heated horizontal tube. The frictional pressure drop during flow boiling is predicted by using two models; the homogeneous model that assumes equal phase velocity and the separate flow model that allows a slip velocity between two phases. The measured frictional pressure drop was compared to a few available correlations. Homogeneous model considerally underpredicted the present data for mixture as well as pure component in the entire mass velocity ranges employed in the present study, while Friedel correlation was found to satisfactorily correlate the frictional pressure drop data as compared to other correlation.

A Study on the Factors Affecting Drop-out from the Domestic Violence Offenders' Treatment group Programs in Korea (한국 가정폭력가해자 치료프로그램의 중도탈락요인)

  • Kim, Jae-Yop;Lee, Ji-Hyun
    • Korean Journal of Social Welfare
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    • v.60 no.3
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    • pp.231-251
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    • 2008
  • The purpose of this study was to determine the factors affecting the drop-out from the domestic violence offenders' treatment group programs in Korea, on the assumption that it would be an important challenge to prevent the domestic violence offenders from dropping out from their treatment group programs in order to protect the victim women and improve effectiveness of the programs. For this purpose, the researchers sampled a total of 280 domestic violence offenders who had participated in the domestic violence offenders' treatment programs operated by 65 domestic violence counselling organizations throughout the nation. As a result, it was found that 159(56.8%) out of the 280 offenders had completed the programs, while 121(43.2%) had dropped out from the programs. As a consequence of comparing the two groups, it was disclosed that they differed significantly in terms of cohabitation with spouse and attitude toward sex role. As a result of the logistic regression analysis for the factors affecting the drop outs from the treatment group program, it was found the significant factors were employment, path of being referred to the program and attitude toward sex role.

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