• Title/Summary/Keyword: Head variation

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Assessment of the Posture Function by Head Movement (상체움직임에 따른 자세기능의 평가)

  • Kim, Jeong-Lae;Hwang, Kyu-Sung;Nam, Youg-Seok
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.5
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    • pp.131-135
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    • 2014
  • The purpose of this study was to show the detection of the head movement within relatively the posture function. An analysis of the posture function was inquired a displacement that the ranges of stance direction showed generally a variation across all condition through the head movement. CNS condition (C_RL-MIN-AVG) was verified slightly greater variation at $0.226{\pm}0.04$ units. Somatosensory condition (So_$RL-_{MIN-AVG}$) was verified slightly greater variation at $0.939{\pm}0.46$ units. Vestibular condition (Ve_$RL-_{MIN-AVG}$) was verified slightly greater variation at $4.009{\pm}1.05$ units. Vision condition (Vi_$RL-_{MIN-AVG}$) was verified greater variation at $8.336{\pm}4.05$ units. When the movement head of vision characteristic function was presented a diminutive variance. On the CNS characteristic condition of the movement head function was presented a diminutive variance.

Development of Infiltration Model Considering Temporal Variation of Soil Physical Properties Under Rainfalls (토양의 물리적 특성의 변화를 고려한 강우의 침투모형 개발)

  • 정하우;김성준
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.35 no.3
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    • pp.36-46
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    • 1993
  • The purposes of this study are to develop three-layered Green-Ampt infiltration model considering temporal variation of physical properties of soil and to evaluate the model with field experiment on bare-tilled and soybean-growing soil plots under natural rainfalls. Infiltration tests were conducted on a sandy loam soil. The model has three-layered soil profile including a surface crust, a tilled layer, a subsoil and considers temporal variation of porosity, hydraulic conductivity, capillary pressure head on a tilled layer by natural rainfalls and canopy density variation of crop. Field measurement of porosity, average hydraulic conductivity and average capillary presure head on a tilled layer were conducted by soil sampler and air-entry permeameter at regular intervals-after tillage. It was found that temporal variation of porosity and average hydraulic conductivity might be expressed as a function of cumulative rainfall energy and average capillary pressure head might be expressed as a function of porosity of a tilled soil. The model was calibrated by an optimization technique, Hooke and Jeeves method using hourly surface runoff data. With the calibrated parameters, the model was verified satisfactorily.

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Variation in Significant Difference of Sausage Textural Parameters Measured by Texture Profile Analysis (TPA) under Changing Measurement Conditions

  • Shin, Sun-Hwa;Choi, Won-Seok
    • Food Science of Animal Resources
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    • v.41 no.4
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    • pp.739-747
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    • 2021
  • This study examined the measurement conditions of the texture profile analysis (TPA) experiments that are typically used to measure the physical properties of sausage. As the measurement conditions (compression ratio and cross-head speed) were changed, the significant differences between the values of textural parameters (hardness, adhesiveness, springiness, cohesiveness, chewiness) of samples changed. Furthermore, among the measurement conditions, there was more variation in the significant difference between the value of samples due to a change in the compression ratio than due to a change in the cross-head speed. The highest variation in significant difference was observed between the values of cohesiveness of samples due to changes in measurement conditions, whereas the lowest variation in significant difference was observed between the values of springiness of samples due to change in measurement conditions. Therefore, it is desirable to provide a clear basis for setting specific measurement conditions for TPA test, since significant differences in the values of textural parameters of samples were caused by differences in cross-head speed or compression ratio, not by a difference in samples, when analyzing the cohesiveness of sausage, especially.

Variation in radial head fracture treatment recommendations in terrible triad injuries is not influenced by viewing two-dimensional computed tomography

  • Eric M. Perloff;Tom J. Crijns;Casey M. O'Connor;David Ring;Patrick G. Marinello;Science of Variation Group
    • Clinics in Shoulder and Elbow
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    • v.26 no.2
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    • pp.156-161
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    • 2023
  • Background: We analyzed association between viewing two-dimensional computed tomography (2D CT) images in addition to radiographs with radial head treatment recommendations after accounting for patient and surgeon factors in a survey-based experiment. Methods: One hundred and fifty-four surgeons reviewed 15 patient scenarios with terrible triad fracture dislocations of the elbow. Surgeons were randomized to view either radiographs only or radiographs and 2D CT images. The scenarios randomized patient age, hand dominance, and occupation. For each scenario, surgeons were asked if they would recommend fixation or arthroplasty of the radial head. Multi-level logistic regression analysis identified variables associated with radial head treatment recommendations. Results: Reviewing 2D CT images in addition to radiographs had no statistical association with treatment recommendations. A higher likelihood of recommending prosthetic arthroplasty was associated with older patient age, patient occupation not requiring manual labor, surgeon practice location in the United States, practicing for five years or less, and the subspecialties "trauma" and "shoulder and elbow." Conclusions: The results of this study suggest that in terrible triad injuries, the imaging appearance of radial head fractures has no measurable influence on treatment recommendations. Personal surgeon factors and patient demographic characteristics may have a larger role in surgical decision making. Level of evidence: Level III, therapeutic case-control study.

Development of head loss coefficient formula at surcharged four-way combining square manhole with variation of inlet flow (유입유량 변화를 고려한 과부하 4방향 사각형 합류맨홀에서의 손실계수 산정식 개발)

  • Jo, Jun Beom;Kim, Jung Soo;Yoon, Sei Eui
    • Journal of Korea Water Resources Association
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    • v.50 no.12
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    • pp.877-887
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    • 2017
  • The energy losses due to surcharged flow at four-way combining manhole, which is mainly installed in the downstream of urban sewer system, is the main cause of inundation in urban area. Surcharged four-way combining manholes form various flow configuration such as straight through, T-type, and four-way manholes depending on variation of inflow discharge in inlet pipes. Therefore, it is necessary to analyze change of energy loss and estimate head loss coefficients at surcharged four-way combining manhole with variation of inflow discharge ratio. The hydraulic experimental apparatus which can change inflow ratios were installed to analyze the flow characteristics at four-way combining manhole. In this study, to calculate the head loss coefficient according to change of the inflow discharge ratios at the surcharged four-way combining square manhole, the discharge conditions of 40 cases which the inflow ratios of each inlet pipe were changed by 10% interval was selected. The head loss coefficient at surcharged square manhole showed the lowest value of 0.40 at the straight manhole and the highest value of 1.58 at the $90^{\circ}$ junction manhole. In the combining manholes (T-type and four-way), the head loss coefficients were calculated more higher as the lateral flow rate was biased. The contour map of head loss coefficient range was constructed by using the estimated head loss coefficients and the empirical formula of head loss coefficients was derived to consider the variation of inflow discharge ratios at the surcharged square manhole. The empirical formula could be applied to the design and assessment of the urban drainage system.

Antenna Efficiency Variation by the Influence of Human Body (인체의 영향에 의한 안테나 효율의 변화)

  • Lee, Yong-Joo;Han, Jun-Hee;Yang, Woon-Geun
    • Journal of IKEEE
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    • v.12 no.4
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    • pp.185-195
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    • 2008
  • In this paper, PIFA(Planar Inverted F Antenna) which operates in PCS(Personal Communication System) band is designed and characteristics are investigated. Designed PIFA was installed in three types of handsets, folder, bar, slide, and the performance was evaluated. Head and hand phantom were added to make the most similar environment to real condition of mobile phone use, and influences on antenna performance were analyzed. The simulation results confirm radiation patterns are greatly changed and antenna efficiency is decreased by the effect of human body. Performance variation of the mobile handset antenna was observed as changing the angle between mobile handset and head phantom from $0^{\circ}$ to $2^{\circ},\;4^{\circ}$ to confirm the variation caused by the relative position of mobile handset and head phantom. Directivity was decreased gradually as the antenna goes away from head phantom, and showed the trend of increasing efficiency. But in the case of bar type, where the position of antenna is relatively close to head phantom, that trend didn't show. It was confirmed that the shape of handset has a great effect on the performance.

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Analysis of the Hydraulic Head Affected by Stage of Tidal Rivers (감조구역에서 지하수 수두의 거동 해석)

  • 김민환;이재형
    • Journal of the Korean Society of Groundwater Environment
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    • v.2 no.1
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    • pp.30-37
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    • 1995
  • In the tidal compartment, the hydraulic head is affected by the stage of tidal rivers. For groundwater or construct works, head variation of groundwater should be considered in zone of this aquifer. A numerical analysis is performed which has an 1-dimemsional explicit finite difference scheme to show the head variation of groundwater with tidal stage and hydraulic conductivity, etc. The stability of the numerical scheme is validated by using the analytic solution. The head variation of groundwater is observed for various tidal amplititude and hydraulic conductivity, mean hydraulic gradient and pumping at any point. The range of influence corresponding to the parameters used in this study is about 60m. This value is not beyond a wave length (equation omitted). There was a pumping at a constant rate out of aquifers affected by tide and not affected by tide. Because pumping head in aquifer affected by tide is short, the expense of electric power is economized in this zone. These results are applicable to trace of contaminant transport, efficient operation of groundwater, and examination of the safety and stability of works in the tidal compartment.

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An Experimental Study on the Measurement of Instantaneous Surface Temperature and Heat Flux on the Cylinder Head Surface of DI Diesel Engine (DI 디젤기관 실린더 헤드표면의 순간온도 및 열유속 측정에 관한 실험적 연구)

  • 이재순;김기태;이현구;강태경;우종헌;김수성
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.5
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    • pp.178-187
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    • 1997
  • For the experimental measurement of heat flux of DI diesel engine combustion chamber, the instantaneous temperature probes and data acquisition system were developed. By the analysis of measured temperatures at the cylinder head, the temperature at the point 3 which is located between intake and exhaust valve was higher than that of the other points. Temperatures at the point located mear the exhaust valve were higher than those of intake valve. The instantaneous and mean temperature at the cylinder head increases proportionally to the increase of the engine speed, while the temperature swing varies inversely. Temperature swings have influence on the maximum heat flux values from gas into head surface. It has been verified that these probes and data acquisition system perform well by the comparison of the trend of instantaneous temperature variation with that of measured combustion chamber pressure variation with respect to crank angle. It is presumed that these probes could be used in the measurement of other parts of combustion chamber as piston, cylinder wall etc. for the future study.

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A Study on Automatic Compensation for Head Lamps Cut-off Line Under Load Variation (차량 하중 변동에 따른 전조등 컷오프라인 자동 보상에 대한 연구)

  • Kim, Ki-Hyeon;Kim, Jun-Hyeon;Byeon, Dong-Kyu;Lee, Dong-Ik
    • Transactions of the Korean Society of Automotive Engineers
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    • v.19 no.2
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    • pp.92-97
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    • 2011
  • Vehicle lightings are very important for safe driving during night time. Since the eye recovery time after an exposure to oncoming headlights would take after several seconds, the aiming point of vehicle head lamps have to pass safety requirements. Despite the fact that vehicle inclination is variable with vehicle load conditions, the head lamps aiming point is usually fixed at a constant position which is set by car manufacturer. Consequently, vehicle head lamps under varying load conditions often make people in the opposing vehicle uncomfortable, and even worse, can cause an accident. This paper presents an active vehicle lighting mechanism to automatically adjust its aiming point, or cut-off line, in order to compensate the change in vehicle inclination resulting from load variations. The effectiveness of the proposed method is demonstrated through a set of simulations and experiments with a real vehicle.

Experimental Study on Adjustment of Inlet Nozzle Section to Flow Rate Variation for Darrieus-type Hydro-Turbine

  • Watanabe, Satoshi;Shimokawa, Kai;Furukawa, Akinori;Okuma, Kusuo;Matsushita, Daisuke
    • International Journal of Fluid Machinery and Systems
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    • v.5 no.1
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    • pp.30-37
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    • 2012
  • A two dimensional Darrieus-type turbine has been proposed for the hydropower utilization of extra-low head less than 2m. In a practical use of Darrieus-type hydro-turbine, head and flow rate may be varied temporally and seasonally. Considering that the cost advantage is required for the low head hydro turbine system, the Darrieus turbine should be operated with high efficiency in the wider range of flow rate possibly by using an additional device with simpler mechanism. In the present paper, an adjustment of inlet nozzle section by lowering the inlet nozzle height is proposed to obtain the preferable inlet velocity in low flow rate conditions. Effects of resulting spanwise partial inlet flow are investigated. Finally, an effective modification of inlet nozzle height over flow rate variation is shown.