• Title/Summary/Keyword: induced ground

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Surrounding rock pressure of shallow-buried bilateral bias tunnels under earthquake

  • Liu, Xin-Rong;Li, Dong-Liang;Wang, Jun-Bao;Wang, Zhen
    • Geomechanics and Engineering
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    • v.9 no.4
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    • pp.427-445
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    • 2015
  • By means of finite element numerical simulation and pseudo-static method, the shallow-buried bilateral bias twin-tube tunnel subject to horizontal and vertical seismic forces are researched. The research includes rupture angles, the failure mode of the tunnel and the distribution of surrounding rock relaxation pressure. And the analytical solution for surrounding rock relaxation pressure is derived. For such tunnels, their surrounding rock has sliding rupture planes that generally follow a "W" shape. The failure area is determined by the rupture angles. Research shows that for shallow-buried bilateral bias twin-tube tunnel under the action of seismic force, the load effect on the tunnel structure shall be studied based on the relaxation pressure induced by surrounding rock failure. The rupture angles between the left tube and the right tube are independent of the surface slope. For tunnels with surrounding rock of Grade IV, V and VI, which is of poor quality, the recommended reinforcement range for the rupture angles is provided when the seismic fortification intensity is VI, VII, VIII and IX respectively. This study is expected to provide theoretical support regarding the ground reinforcement range for the shallow-buried bilateral bias twin-tube tunnel under seismic force.

Meta-analysis on the Effectiveness of Pulmonary Rehabilitation Program on Exercise Capacity/Tolerance and General Health Status (만성 폐쇄성 폐질환 환자를 위한 호흡재활 중재가 운동 능력 및 내구성, 일반적 건강상태에 미치는 효과에 대한 메타분석)

  • 오현수
    • Journal of Korean Academy of Nursing
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    • v.33 no.6
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    • pp.743-752
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    • 2003
  • Purpose: This study was conducted to combine the effects of pulmonary rehabilitation program (PRP) on exercise capacity/tolerance and general health status of COPD patients based on the primary research results examined the effects of PRP, Method: Seventeen studies were selected by the sampling criteria established to include the studies that reported enough statistics necessary to conduct meta-analysis. Result: According to the study results, the most effective indicators for exercise capacity/tolerance were exercise time (such as cycling time or treadmill walking time) and ground walking distance within given time (6 minutes or 12 minutes), whereas effects on such indicators as VE and VO$_2$ were not statistically significant. PRP induced significant effect on patients' general health status, frequently measured by physical, psycho-emotional, and holistic indicators, the enhancement on psycho-emotional dimension resulted from PRP was more prominent than those of the other dimensions. From the results, it was noted that the place where PRP was given and the contents of PRP exercised their influence on the outcome variables. Which body part was trained was also one of the important factors that influence on the patients' perception of dyspnea during exercise as well as on exercise capacity/tolerance. Conclusion: PRP including exercise training significantly improved the exercise capacity and general health status of COPD patients.

Behaviour of Shallow Foundations Subjected to Blast Loads and Related Liquefaction

  • Ritika, Sangroya;Choudhury, Deepankar;Park, Young Jin;Shin, Eun Chul
    • Journal of the Korean GEO-environmental Society
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    • v.18 no.10
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    • pp.5-14
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    • 2017
  • In recent years, world has witnessed many man-made activities related to both above and underground blasts. Details on behaviour of shallow foundations subjected to blast loads and induced liquefaction is scarce in literature. In this paper, typical shallow strip foundation in saturated cohesionless soils subjected to both above and underground blasting have been simulated by using finite difference based numerical model FLAC3D. Peak particle velocity (PPV) has been obtained to propose critical values for which bearing capacity failure for shallow foundations with soil liquefaction can occur. Typical results for pore pressure ratio (PPR) for various scaled distances are compared to PPR values obtained by using empirical equation available in literature which shows good agreement. Critical design values obtained in the present study for PPV and PPR to estimate the scaled distance, bearing capacity failure and liquefaction susceptibility can be used effectively for design of shallow strip foundation in cohesionless soil subjected to both above and under ground blast loads.

Performance Improvement of T-50 Fine Tracking Using Pilot Prefilter (조종사 필터에 의한 T-50 정밀추적 성능 향상)

  • Kim, Chong-Sup;Bae, Myung-Whan;Hwang, Byung-Moon;Koh, Gi-Oak;Kang, Cheul;Sung, Duck-Yong
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.625-630
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    • 2004
  • An advanced method of Relaxed Static Stability (RSS) is utilized for improving the aerodynamic performance of modern version supersonic jet fighter aircraft. The laws of flight control system utilize RSS criteria in both longitudinal and lateral-directional axes to achieve performance enhancements. Particularly, the design of longitudinal control laws for utilizing RSS methods greatly affects the performance of the aircraft in Air-to-Air Tracking and Air-to-Ground modes, which improves weapon delivery. In the area of Airto- Air Tracking, the development of longitudinal control laws aids in the fine tracking and gross acquisition of other aircraft. This paper proposes that Air-to-Air fine tracking can be improved via RSS control law design methods without effecting Air-to-Air gross acquisition.

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Weight Loss Effect of Wax Gourd (동아의 체중조절 효과)

  • 홍석산;이승환;김철용;권석형;황보식
    • The Korean Journal of Food And Nutrition
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    • v.15 no.4
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    • pp.289-294
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    • 2002
  • This study attempted to evaluate the effectiveness of function of Wax Ground for obesity and the related disease of adult people can be developed by the combination of the 17 food materials screened in this study. The experiments using Sprague-Dawley male rats show that seventeen kinds of food material inhibited the increase of body weight gain, energy intake, fat pads weight, liver triglycerides content, atherogenic index, and blood glucose concentration induced by cafeteria diet. Oral administration of wax gourd decreased most body weight gain, energy intake, fat pads weight, and blood glucose concentration. Liver triglycerides content was the lowest in the group administered mulberry stem extract and the group administered pine leaves showed the lowest atherogenic index. The combined administration of wax gourd, mulberry stem extract and pine leaves improved more the obesity and related symptoms than the individual administrations.

Numerical Simulation on Dispersion of NOx in Vehicular Exhaust Gas around Buildings (빌딩주변 자동차 배기가스중의 NOx 분산에 관한 수치해석)

  • Jeon, Yeong Nam;Jeong, O Jin;Song, Hyeong Un
    • Journal of Environmental Science International
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    • v.13 no.7
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    • pp.655-660
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    • 2004
  • This paper demonstrates the numerical simulation of three dimensional flow pattern for vehicular exhaust dispersion in the street canyons. The wind flow around buildings in urban is computed by the SIMPLEST method. The convection-diffusion equation was used to compute the $NO_X$ concentration level near buildings. Details are given of important boundary conditions and turbulence quantities variations. The simple turbulence model was used for unisotropic viscous effect. A control-volume based finite-difference method with the upwind scheme is employed for discretization equation. The simple turbulence model applied in this study has been verified through comparison between predicted and measured data near buildings. By the predictive results, the updraft induced by the presence of high-rise buildings is important in the transport of street level pollutant out from the street canyons. Our suggestion for reducing ground level pollution is to have high-rise buildings constructed or to reduce the channelling effect of street canyons.

An Improved Model for Grounding System Using Examination of Dangerous Voltage (위험전압 검토에 따른 개선된 접지설비 모델)

  • Shin, Bog-Sung;Hong, Soon-Seuk
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.4
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    • pp.68-77
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    • 2008
  • When we design the grounding grid, dangerous voltage IEEE Std. 80 method has been commonly used in the domestic area. However there is not appropriative examination of ground design environment. So in this paper, we examined of IEEE Std. 80 touch voltage method's marginal utility and we induced corrective factor for those problems by comparison between IEEE Std. 80 touch voltage value and simulation experimentation value. Moreover, Logistic model's corrective factor we proved the maximum accidental error has reduced less than 10[%].

Photo Sensor Based Measurement and Noise Reduction of Dynamic Weights (광 센서에 기반한 동하중의 측정 및 잡음 감소)

  • Shin, Dae-Jung;Na, Seung-You;Kim, Jin-Young
    • The KIPS Transactions:PartC
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    • v.12C no.4 s.100
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    • pp.519-524
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    • 2005
  • Due to various types of errors added to dynamic weight measurement data, proper methods to reduce measurement errors are required to produce reliable weights. It is very difficult to reduce the measurement error due to excessive oscillation of the system. To cope with parasitic types of errors in real systems, information provided by the photo sensors are utilized and combined in such a way to reduce the measurement errors of load cells. In addition to four channels of load cells from a model trailer, photo sensors are used to obtain the information to compensate the error induced from vertical movement of the vehicle due to the variation of ground level. A model trailer system is run to verify the effectiveness of the proposed method to reduce noise of dynamic weight measurements.

Excavation Behavior of an Earth Retaining Wall Supported by Large Diameter Soil-cement Blocks (대구경 소일-시멘트 교반체로 보강한 토류벽의 굴착 시 거동 분석)

  • Kim, YoungSeok;Choo, Jinhyun;Cho, Yong Sang
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.2C
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    • pp.65-74
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    • 2011
  • This paper presents an analysis of excavation behavior of an earth retaining wall supported by large diameter soil-cement blocks at a field trial site. The concept and design philosophy of the large soil-cement block reinforcement are described first. The wall behavior during sequential excavations up to 9.8 m is analyzed based on the measured lateral wall movements and earth pressures. The settlements of adjacent ground are examined by field measurements and inverse numerical analysis. The results indicate that, when the lengths of the soil-cement blocks were over 0.45 H (H: wall height), the displacements and the earth pressures induced by the excavations were similar to those supported by conventional methods such as soil nailing.

Studies on the Pore of Coating Layer and Printability (I)-Effect of Pigment Size on Pore of Coating Layer (도공층의 공극과 인쇄적성에 관한 연구(제 1보)-안료의 입자크기가 미치는 영향)

  • 김창근;이용규
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.31 no.3
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    • pp.26-34
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    • 1999
  • This paper was intended to find out the relationship between optical and interior properties of coated paper and printability with the variation of particle size of ground calcium carbonate(GCC) by using Mercury Porosimeter, and to find out the pore properties of coated paper as well. The viscosity and water retention of coating color was increased and smothness, sheet gloss and porosity of coated paper were improved as the particle size of GCC was decreased. However, there was no difference in opacity and brightness of coated paper. The pore volume of coated paper was decreased, but the number of pores was drastically increased according to the decrease of the particle size of GCC. The weight of ink transferred into coated paper was increased in proportion to pore volume of coated paper. However, the weight of damping water and ink induced toward coated paper was slightly increased. Ink setting was accelerated printing gloss was not changed. Therefore, optical and interior properties of coated paper seemed to be affected by the pore property of coated paper and printability was also affected by it.

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