• Title/Summary/Keyword: ground contact analysis

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Semantics for Specific Indefinites

  • Yeom, Jae-Il
    • Language and Information
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    • v.1
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    • pp.227-276
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    • 1997
  • There has been no nuanimous analysis of specific indefinites. It is still disputed even whether specificity is a matter of semantics of pragmatics. In this paper, I introduce some properties of specific indefinites, and explain them based on the meaning of specificity. Specificity intuitively means that the speaker or someone else in the context has some individual in mind, which is generally accepted among liguistics. The main issue is how to represent the meaning of 'have-in-mind'. I review some philosophical discusstions of cognitive contact and show that when the use of an expression involves 'have-in-mind', the expression is rigid designator in the belief of the agent who has an individual in mind. in the use of a specific indefinite, this applies only to the information state of the agent of 'have-in-mind'. To represent this asymmetry, I propose a new theory of dynamic semantics, in which a common ground consists of multiple information states, as many as the number of the participants in a conversation. Moreover, each information state is structured as a set of epistemic alternatives, which is a set of possible information states of a participant in the context. Based on this semantics, the properties of specific indefinites are explained.

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Characteristics on the distribution of salinity of airborne sea salt by height (높이에 따른 비래염분량의 감소 특성)

  • Lee Jong Suk;Choi Won Sung;Kim Do Gyeum;Moon Han Young
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05b
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    • pp.261-264
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    • 2005
  • For concrete structures immersed in seawater, the concentration of chloride used to estimate the chloride diffusion coefficient can be defined as the seawater chloride concentration. However, for seashore concrete structures which are not coming into direct contact with seawater, establishing the interface concentration of chloride becomes delicate. In addition, concrete structures are greatly affected by salt attack primarily due to airborne sea salt like it can be seen through the corrosion of rebar. This study intends to investigate characteristics on the salinity of airborne sea salt by height. Salinity measurement devices were installed at height of 2, 10 and 19m on the seashore water tower located in the area of Samchuk in the Eastern coast. Analysis results of the decrease of salinity with respect to the height above the ground at a distance of 30m from the seashore showed that the reduction reached about 40$\%$ at a height of 10m and 60$\%$ at 20m.

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Analysis of Characteristics on the Static Electricity by Streaming Electrification (유동대전에 의한 정전기 특성 분석)

  • Kim, Gil-Tae;Lee, Jae-Keun
    • Journal of the Korean Society of Safety
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    • v.20 no.3 s.71
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    • pp.42-46
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    • 2005
  • The static electricity by thinner flow and discharge energy is investigated experimentally for the purpose of preventing the electrostatic discharge and damage. Test system for evaluating streaming electrification consists of a teflon pipe, a reservoir tank a pump, flowmeters and an electrometer. When dielectric liquid flows through a pipe from one vessel to another, the potential difference generated in the collecting vessel is due to the accumulation of charges. These charges result from the convection of a part of the electrical double layer existing in the tube at the contact between the liquid and the inner wall. When the fluid velocity increases, the electric current increases proportionally. The charging current and accumulated charges by streaming electrification at the thinner velocity of 40cm/s are measured a range of 5 nA and $0.27{\mu}C$ respectively. This amount of static discharge energy generated by streaming electrification is enough to ignite flammable solvent. Therefore surface electric potential should decrease by using electrostatic shielding and ground.

Determining of Ground Condition Criteria for Dam Reinforced RIM Grouting (댐체 강화 RIM부 그라우팅을 위한 지반상태 기준 결정)

  • Han, Kiseung;Lee, Donghyuk;Park, Duhee
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.42 no.2
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    • pp.181-186
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    • 2022
  • Dam slope RIM is a highly important contact interface where the main body and the base surface are connected. In general, when the grouting for the slope of the dam structure is designed, it is planned using limited data (drilling, geological map, etc.). This makes it very difficult to accurately consider the original ground characteristics of the slope RIM grouting target, In addition, when the grouting volume planned during the design is drilled and injected into the original ground where the waterstop is secured, there is a possibility that the original ground with the waterstop is disturbed and the effect of the waterstop is rather diminished. In order to overcome such problems, it is more suitable to first consider geological conditions and determine whether to perform optimal grouting on the original ground through on-site repair tests before performing RIM grouting. In this paper, to determine the grouting of the RIM unit, a pilot hole water pressure test was performed on the rock of the slope in the target section. The analysis shows grouting volume of 1 Lugeon or less, and the cement injection amount also shows the injection result of 1 kg/m or less. In this case, performing grouting is rather counterproductive. This result can be evaluated through a rock of which some degree of order of mass is secured, as it is a dam design standard of 1 Lugeon or less when analyzed, using the results of visual observation and geological map creation during slope cutting. Therefore, in conclusion, it is preferable to make the decision for using RIM grouting on the slope of the dam body structure, based on 1 Lugeon in a rock state, and the cement injection amount also at 1 kg/m.

Basemat Uplifting Effects on Seismic Response of Soil-Structure Interaction System (기초의 부분적 들림이 지반-구조물상호작용 시스템의 지진응답에 미치는 영향)

  • Joe, Yang Hee;Chang, Sung Pil
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.10 no.1
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    • pp.37-45
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    • 1990
  • An analytical procedure is proposed for the seismic analysis of a soil-structure interaction system with besemat uplift, including the effects of concurrent vertical seismic ground motion, nonlinear distribution of bearing soil pressure under the basemat, and 3-dimensional behavior of the system. The soil-structure interaction system is assumed to have rectangular-shaped basemat on elastic half-space. Nonlinearity of soil spring constants and soil damping coefficients induced by the base mat uplift is modeled by considering not only the reduction of contact area between soil and structure but also the effects of rigid body rotational motion of the superstructure, and the shift in the point of action of the resultant reaction on the basemat. Throught various parametric studies. it has been confirmed that the seismic responses of the superstructure reduce notably while response at the basemat increases considerably. The results also show that the effects of concurrent vertical ground motion. nonlinear soil pressure distribution under basemat, and 3-dimensional behavior of the system shall be included in uplift analysis in order to obtain the correct structural responses.

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ATPDraw Simulation for Transient Phenomena Analysis of Electrical Shock Underwater (수중 전격 과도현상 해석을 위한 ATPDraw 시뮬레이션)

  • Jung, Jong-Wook;Jung, Jin-Soo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.6
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    • pp.48-54
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    • 2007
  • This paper describes the analysis of transient phenomena on the point that a human body suffers an electrical shock. A couple of case studies were discussed by using an ATPDraw simulation tool. Two models for the case studies were constructed on the assumption that the electrical shock event takes place under water to simulate the severest condition ; the first model that the human body contacts with an energized part exposed to water ; the second model that both hands and feet simultaneously contact with the ground under water. After modeling, the transient phenomena for the models were analyzed by comparing the voltages and currents calculated at each part of the human body. As a result steep front kicks in voltage and current were observed as transient phenomena on the point that the human body contacts with the energized part exposed to water in the first model and the magnitudes of the kicks considerably increased. It was considered however, the effect of the kicks due to the commercial power source on the human body could be neglected because the product of the current through the body and the short duration is less than the safety limit. When both hands and feet simultaneously contact with the ground in the second model, the voltage generally decreased all over the body parts, while the current flowing through the chest abruptly increased. The duration of this current was very shot, as well, thus its effect on the electrical shock is considered insignificant. After all, it was confirmed through the simulation results that the electrical shock depends on the magnitude in voltage and the body impedance.

Characteristic Analysis of Superconducting LSM for the Wheel-rail-guided Very High Speed Train according to Winding Method of the Ground 3-phase Coils (휠-레일 방식 초고속열차용 초전도 선형동기전동기의 지상권선 방식별 특성 분석)

  • Park, Chan-Bae;Lee, Byung-Song;Lee, Chang-Young
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.8
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    • pp.1164-1169
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    • 2014
  • Recently, an interest in a hybrid system combining only the merits of the conventional wheel-rail system and Maglev propulsion system is growing as an alternative to high-speed maglev train. This hybrid-type system is based on wheel-rail method, but it enables to overcome the speed limitation by adhesion because it is operated by a non-contact method using a linear motor as a propulsion system and reduce the overall construction costs by its compatibility with the conventional railway systems. Therefore, the design and characteristic analysis of a coreless-type superconducting Linear Synchronous Motor (LSM) for 600km/h very high speed railway system are conducted in this paper. The designed coreless-type superconducting LSMs are the distributed winding model, the concentrated 1 layer winding model and the concentrated 2 layer winding model, respectively. In addition, the characteristic comparison studies on each LSM are conducted.

Experimental Analysis of the fixed socket strength of a removable soil nail (제거식 쏘일네일의 고정자소켓 강도에 관한 실험적 해석)

  • Kim, Nak-Kyung;Kim, Sung-Kyu;Yun, Seung-Kwon;Cho, Kyu-Wan;Kim, Woong-Kyu;Lee, Chung-Ho
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.1250-1253
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    • 2008
  • As a reinforcement technique, the application of removable soil nailing has been extended to solve the public grievance of typical soil nailing such as the geotechnical environmental problem and invasion of adjacent land. In the case of removable soil nailing, pullout capacity of the nail depends on the adhesive strength of a fixed socket. Because the existing fixed socket is made from a plastic product, the strength of a socket is less than a steel bar and then the yield failure by abrasion and deformation is occurred on the steel bar-socket contact surface. In this study, therefore, experimental analysis from laboratory test of a removable soil nail equipped with steel socket, improving the adhesive strength of steel bar-socket connection is performed to estimate the increase effect of pullout capacity of a soil nail.

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Forensic Engineering Study on the Evaluation of the Structural Stability of the Mobile Crane Accident (차량크레인 전도 사고의 구조 안정성 평가에 관한 법공학적 연구)

  • Kim, Jong-Hyuk;Kim, Eui-Soo
    • Journal of the Korean Society of Safety
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    • v.28 no.3
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    • pp.11-17
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    • 2013
  • Forensic Engineering is the area covering the investigation of products, structures that fail to perform or do not function as intended, causing personal injury or damage to property. To investigate the mobile crane's overturn accident in terms of the forensic engineering, in this study, we identified the accident mobile crane's position and posture before accident by the analysis of the trace resulted by the contact between the outrigger and the ground, and the accident remodeling has been performed using CATIA modeling program in the basis of the accident mobile crane's position and posture information. The accident analysis has been performed by comparing this accident remodeling and the crane's specification, the table of the allowance load about the boom's length and the working radius. Through these studies, the safety accident that may occur in mobile crane can be minimized by performing specialized and systematic investigation of the accident cause in terms of the forensic engineering.

Structure-soil-structure interaction in a group of buildings using 3D nonlinear analyses

  • Sharifi, Behroozeh;Nouri, Gholamreza;Ghanbari, Ali
    • Earthquakes and Structures
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    • v.18 no.6
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    • pp.667-675
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    • 2020
  • The current study compares the effect of structure-soil-structure interaction (SSSI) on the dynamic responses of adjacent buildings and isolated structures including soil-structure interaction (SSI) with the responses of fixed-base structures. Structural responses such as the relative acceleration, displacement, drift and shear force were considered under earthquake ground motion excitation. For this purpose, 5-, 10- and 15-story structures with 2-bay moment resisting frames resting on shallow foundations were modeled as a group of buildings in soft soil media. Viscous lateral boundaries and interface elements were applied to the soil model to simulate semi-infinite soil media, frictional contact and probable slip under seismic excitation. The direct method was employed for fully nonlinear time-history dynamic analysis in OpenSees using 3D finite element soil-structure models with different building positions. The results showed that the responses of the grouped structures were strongly influenced by the adjacent structures. The responses were as much as 4 times greater for drift and 2.3 times greater for shear force than the responses of fixed-base models.