• Title/Summary/Keyword: 하강속도

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Effects of Practical Variations in Fasting, Stress and Chilling Regime on Post-slaughter Metabolic Rate and Meat Quality of Pork Loin (절식, 스트레스 및 냉각속도가 돼지도체의 사후 대사속도와 등심근의 육질에 미치는 영향)

  • Hwang, I.H.;Park, B.Y.;Cho, S.H.;Kim, J.H.;Lee, J.M.
    • Journal of Animal Science and Technology
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    • v.46 no.1
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    • pp.97-106
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    • 2004
  • The study was conducted to investigate the effects of practical variations in feed restriction, pre-slaughter handing and chilling regime on pork quality during ageing. A total of twenty male landraces were allocated into three treatments(i.e., pre-slaughter feeding, stress and chilling regime) in a factorial arrangement. pH, temperature, free calcium ions, WB-shear force, sarcomere length, cooking loss, drip loss and objective color were determined during rigor development and/or 1, 3, 7 d postmortem. Pre-slaughter chasing stress for approximately 15 min had no effects on pH/temperature profile and objective meat quality. There was an interaction(P < 0.05) between the fasting treatment and chi1ling regime for muscle temperature at pH 6.2. Sarcomere length indicated that the current experiment conditions did not induce muscle shortening, with 1.7 to 1.8 ${\mu}m$, in spite of a significant effect of the fasting treatment (P<0.01). Pigs fed until the morning of slaughter showed a low WB-shear force(P < 0.05) until 3 d at I "C. The treatment also resulted in a higher Hunter L* and a*(P < 0.05) at 24 h and 7 d. Fasted pigs showed a significantly(P < 0.05) reduced cooking loss. The current results indicated that feeding upon the morning of slaughter became detrimental on meat color and the negative effect on cooking loss were linearly elevated with increased ageing time. On the other hand, WB-shear force did not distinguishable after 3 d. Collectively, it appeared that feed restriction from a day before slaughter could produce more a desirable meat quality at the time of consuming. However, the limited effect of animal handling and chilling rate on meat quality is not necessarily to extend to that these do not affect pork quality, as that largely depends on experimental design.

An experimental study on the smoke-spread region before reaching the critical velocity for the case of fires in tunnels employing longitudinal ventilation system (종류식 환기 시스템에서 임계속도 도달 전 스모크 확산 영역에 관한 실험적 연구)

  • Ki, Young-Min;Yoon, Sung-Wook;Yoon, Chan-Hoon;Kim, Jin
    • Tunnel and Underground Space
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    • v.16 no.6 s.65
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    • pp.526-535
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    • 2006
  • An experimental study was carried out on a reduced scale tunnel model to grasp the behavioral feature of fire-induced smoke in the long tunnels. Based on Froude modeling, the 1/50 scaled tunnel model (20 m long) was constructed by acrylic tubes and paraffin gas was released inside the tunnel to simulate the 20 MW fire-induced smoke. me test results show, that after approximately 2 minutes of fire generation, was descended from the tunnel ceiling through the decrease of buoyancy, then it was symmetrically propagated about 90 meters for 4 minutes before jet fans were operated. The smoke was effectively controlled when the jet fans were operated and an air stream velocity was getting closed to reach a critical velocity (the minimum air velocity that requires to suppress the smoke spreading against the longitudinal ventilation flow during the tunnel fire situations). It was also found out that a range of smoke was spreaded about 3 meters from the origin of fire but the range was not propagated to the escape direction anymore. The early stage of the In operation, however, showed that the smoke was hardly controlled. It means that the operation of emergency ventilation system has many dangerous factors such as an intercepting breathing zone.

Estimation of Saturation Velocity in Soils During Rainfall using Soil Box Test (모형토조실험을 이용한 강우시 토층의 포화속도 산정)

  • Kim, Chul-Min;Song, Young-Suk;Kim, Hak-Joon
    • The Journal of Engineering Geology
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    • v.25 no.3
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    • pp.377-385
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    • 2015
  • We constructed a model test apparatus to evaluate the dependence of the saturation velocity (Vs) in soils on rainfall intensity (IR). The apparatus comprises a soil box, a rainfall simulator, and measuring sensors. The model grounds (60 cm × 50 cm × 15 cm) were formed by Joomunjin standard sand with a relative density of 75%. The rainfall simulator can control the rainfall intensity to reenact the actual rainfall in a soil box. Time Domain Reflectometer (TDR) sensors and tensiometers were installed in the soils to measure changes in the volumetric water content and matric suction due to rainfall infiltration. During the tests, the soil saturation was determined by raising the groundwater table, which was formed at the bottom of the soil box. [Please check that the correct meaning has been maintained.] The wetting front did not form at the ground surface during rainfall because the soil particles were uniform and the coefficient of permeability was relatively high. Our results show that the suction stress of the soils decreased with increasing volumetric water content, and this effect was most pronounced for volumetric water contents of 20%-30%. Based on a regression analysis of the relationship between rainfall intensity and the average saturation velocity, we suggest the following equation for estimating the saturation velocity in soils: Vsavg (cm/sec) = 0.068IR (mm/hr).

Heat Transfer in Radiatively Participating Gas-Particle Cavity Flows (輻射가 關與하는 氣體-固體粒子 캐비티 流動에서의 熱傳達)

  • 이종욱;이준식;이택식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.3
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    • pp.551-560
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    • 1988
  • Gas-particle two phase flow and heat transfer in a cavity receiving thermal radiation through selectively transparent walls have been analyzed by a finite difference method. Particles injected from the upper hole of the cavity are accelerated downward by gravity and exit through the lower hole while they absorb, emit and scatter the incident thermal radiation. Gas phase is heated through convection heat transfer from particles, and consequently buoyancy induced flow field is formed. Two-equation model with two-way coupling is adopted and interaction terms are treated as sources by PSI-Cell method. For the particulate phase, Lagrangian method is employed to describe velocities and temperatures of particles. As thermal radiation is incident upon horizontally, radiative heat transfer in the vertical direction is assumed negligible and two-flux model is used for the solution of radiative heat flus. Gas phase velocity and temperature distributions, and particle trajectories, velocities and temperatures are presented. The effects of particle inlet condition, particle size, injection velocity and particle mass rate are mainly investigated.

Improving Evaluation of the Basket-to-Handstand Mount by a Technical Training Program on Parallel Bars (평행봉 Basket to Handstand 기술 훈련 프로그램 적용을 통한 향상도 평가)

  • Lee, Chong-Hoon;Back, Jin-Ho
    • Korean Journal of Applied Biomechanics
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    • v.19 no.4
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    • pp.719-728
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    • 2009
  • In this study, a training program was conducted to improve the performance of the basic movement of the basket-to-handstand mount. After completion of the training program, the kinematic comparison of the before and after effects were investigated to provide scientific data about this technique. It is recommended that during P1, the center of body mass at the back should push the hip joint to flex quickly, and the shoulder joint should be maintained at a maximum angle. During P2, the body's center of mass must be accelerated so as to create enough momentum to rise efficiently for this, quick extension of both the hip and the shoulder is required. For safety during P3, it is advised that the speed upwards must be increased and that the hands, shoulders, and hip joint must be extended, as in the posture of a handstand. These results stress to coaches the importance of the bodies speed during the ascent in the motion.

Fuel Economy improvement Method and Performance Evaluation Using Altitude Data (고도 데이터를 이용한 연비 향상 방안과 성능 평가)

  • Choi, Seong-Cheol;Kwon, Mann-Jun;Lee, Sang-Jun;Kim, Young-Il;Oh, Tae-Il;Ko, Kwang-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.5
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    • pp.1947-1953
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    • 2012
  • The vehicle fuel economy is very important issue in the view of global warming. This paper proposes the three fuel economy improvement algorithms which predict the velocity using altitude data of the positions in front of vehicle and estimates their performances. The proposed 3 algorithms are WMGA(Weighted Mean Gradient Angle), RAADE I, II(Reacceleration After Deacceleration I, II). This research extracts the distance and altitude data from received GPS data and calculates gradient angle and road load for each section. The velocity profile according to proposed algorithms is made for Youngdong highway of 213km. And the test vehicle runs along this highway and fuel economy is measured. RAADE II of proposed algorithms showed better performance by 3.571% in comparison to the conventional CVELCONT3.

Scour around Piers in the Stage Hydrograph (수위변화에 따른 교각주위에서의 세굴현상연구)

  • An, Sang-Jin;Yeon, Gi-Seok
    • Journal of Korea Water Resources Association
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    • v.30 no.4
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    • pp.335-346
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    • 1997
  • This study aims at examining closely the scour around a pier due to irregular water stage changes during flood. At the Sangye bridge is located lowermost downstream of the Bocheong stream in the Kum River, the IHP experimental watershed. For this purpose, we have analyzed the change of scour depths due to stage hydrographs of experimental basin by a simulation. To examine the scour phenomenon around a pier due to irregular stage change in flood, we have analyzed the change of scour depth corresponding to stage hydrograph of field watershed after verification of model channel. From this study, the following conclusions are made: First, in case of predicting the maximum scour depth around a pier with stage hydrograph in the state of steady flow, we should choose the highest stage. Second, after increasing the stage, the equilibrium scour depth became smaller than the maximum scour depth. Therefore, in case of estimating the maximum scour depth in rivers, it is recommended that we should consider additional scour depth with is reduced by infilling the sediments.

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Flow Characteristics around Underwater Triangular Structure with Different Inclination (경사도가 다른 수중 삼각형상구조물 주위의 유동특성)

  • Choe, Sang-Bom;Cho, Dae-Hwan
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.20 no.2
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    • pp.241-246
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    • 2014
  • The purpose of this study is to investigate the flow characteristics around underwater triangular structure with various inclination and Reynolds number. A flow fields around the triangular structure model were measured by visualization method and PIV in the circulating water channel. The result of the experiment is where the triangular structure that has a inclination of $45^{\circ}$ and the reynolds number at $Re=2.9{\times}10^3$ showed rising velocity component to 2.7 times of the structure height. When the reynolds number is steady and when the inclination is greater the descending velocity component of the structure's rears current form is greatly shown and for the areas where it's more than y/hs=1.75 has a change in the angle of inclination but it doesn't give a great effect to it.

Development of Fragility Curves for Slope Stability of Levee under Rapid Drawdown (수위급강하에 대한 제방 사면의 취약도 곡선 작성)

  • Cho, Sung-Eun
    • Journal of the Korean Geotechnical Society
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    • v.39 no.10
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    • pp.27-39
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    • 2023
  • To effectively manage flood risk, it is crucial to assess the stability of flood defense structures like levees under extreme flood conditions. This study focuses on the time-dependent probabilistic assessment of embankment slope stability when subjected to rapid water level drops. We integrate seepage analysis results from finite element analysis with slope stability analysis and employ Monte Carlo simulations to investigate the time-dependent behavior of the slope during rapid drawdown. The resulting probability of failure is used to develop fragility curves for the levee slope. Notably, the probability of slope failure remains low up to a specific water level, sharply increasing beyond that threshold. Furthermore, the fragility curves are strongly influenced by the rate of drawdown, which is determined through hydraulic analysis based on flood scenarios. Climate change has a significant impact on the stability of the water-side slope of the embankment due to water level fluctuations.

Design of Enhanced IEEE 1500 Wrapper Cell and Interface Logic For Transition Delay Fault Test (천이 지연 고장 테스트를 위한 개선된 IEEE 1500 래퍼 셀 및 인터페이스 회로 설계)

  • Kim, Ki-Tae;Yi, Hyun-Bean;Kim, Jin-Kyu;Park, Sung-Ju
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.44 no.11
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    • pp.109-118
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    • 2007
  • As the integration density and the operating speed of System on Chips (SoCs) become increasingly high, it is crucial to test delay defects on the SoCs. This paper introduces an enhanced IEEE 1500 wrapper cell architecture and IEEE 1149.1 TAP controller for the wrapper interface logic, and proposes a transition delay fault test method. The method proposed can detect slow-to-rise and slow-to-fall faults sequentially with low area overhead and short test time. and simultaneously test IEEE 1500 wrapped cores operating at different core clocks.