• Title, Summary, Keyword: Semi Floor

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Effects of semi-floor pens on growth performance and stress in weaning pigs (사육면적 증가를 위한 반층돈사의 활용이 이유자돈의 성장 및 스트레스에 미치는 영향)

  • Chung, Woolim;Lee, Geonil;Hong, Jinsu;Jeong, Jaehark;Kim, Yooyong
    • Journal of Animal Environmental Science
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    • v.22 no.1
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    • pp.27-34
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    • 2016
  • The objective of this study was to increased breeding area in same size pig pen and growth performance of weaning pigs. A total of 330 crossbred ($6.68{\pm}0.36kg$) weaning pigs were subjected to a 42-day feeding trial(3 pens/treatment) in which effects of the semi-floor were compared : NC; Negative control ($0.23m^2/pig$; 40 pigs/pen), PC; Positive control($0.30m^2/pig$; 30 pigs/pen) and Semi-floor($0.30m^2/pig$; 40 pigs/pen). There was a significant effect on BW at 6 week along all treatment(P<0.01). There was a effect of Semi-floor treatment on ADG(average daily gain) only during the first 3 week after weaning(P<0.01). No significant effect was observed in the ADFI during the experiment period. NC treatment had significantly lower BUN value than other treatments(P<0.05). The results from immune and stress response with semi-floor suggest that no negative effects in their blood analysis. Consequently, semi floor treatments increased additional breeding area and also growth performance rather than other treatments in weaning pigs.

Sound transmission loss measurement of railway vehicle floor using semi-reverberation room (간이잔향실을 이용한 철도차량 바닥재의 음향투과손실 측정)

  • Shin, Bum-Sik;Chun, Kwang-Wook;Choi, Yeon-Sun
    • Proceedings of the KSR Conference
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    • pp.1420-1425
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    • 2008
  • This study is to examine the sound transmission loss of a railway vehicle floor. To this end, a semi-reverberation room was constructed. The semi-reverberation room was made of a railway vehicle floor between the sound radiating chamber and the sound receiving chamber. To block the sound, the wall was made of acryl, urethane foam, wood, and glass fiber. The test followed the KS F 2808 standard, and a typical reverberation room was used to verify the performance of the semi-reverberation room. As a result, comparison of the measurements showed that the test results of the semi-reverberation room had the same tendency as those of the reverberation room. Consequently it was possible to measure the sound transmission loss of railway vehicle structures using the semi-reverberation room.

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Flexural Performance Evaluation of Semi-slim floor Composite Beams for Reduction of Story Height (층고절감을 위한 반슬림플로어 합성보의 휨성능 평가)

  • Lee, E.T.;Lee, Sang Hoon;Jang, Bo Ra
    • Journal of Korean Society of Steel Construction
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    • v.20 no.1
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    • pp.165-173
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    • 2008
  • In order to promote the practicality of high-rise steel buildings, the development of structural system which have the better fire resistance, the changeable plan, and the quality control of construction with general composite beams is needed. In this research, new semi-slim floor which the defect of general slim floor was complemented was evaluated to investigate the concrete integration with slim-flor beam and the flexural performance. 5 simply supported semi-slim floor beam tests were performed with parameters; structural form of slab support beam, slab thickness, with or without web opening, and shear connection. Experimental results showed that all specimen s had good ductile behavior.

An Experimental Study on the Development of Semi-Slim Composite Beam with Traperzodial Composite Deck Plate (골형 합성 테크플레이트를 사용한 반슬림 합성보의 개발에 관한 실험적 연구)

  • Bae, Kyu-Woong;Oh, Sang-Hoon;Heo, Byung-Wook;Yang, Myung-Sook
    • Journal of Korean Society of Steel Construction
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    • v.13 no.1
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    • pp.29-40
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    • 2001
  • Steel frames are increasingly used in commercial buildings. and most steel frames are designed to achieve composite action with the concrete floor slab. The advantages of 'composite construction' are now well understood in terms of structural economy. good performance in service. and ease of construction. But. these conventional composite construction system are difficult to apply steel framed apartment due to their large depth. So. in this study we developed Semi Slim Floor system which could reduce the overall depth of composite beam. Semi Slim Floor system is a method of steel frame multi-story building construction in which the structural depth of each floor is minimised by incorporating the steel floor beams within the depth of the concrete floor slab. Twelve composite slab specimens with different deck-type. slab width. with or without stud bault and concrete topping thickness were tested to evaluate the flexural capacity.

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Application of Semi-active TMD for Vibration Control of Floor Slab (바닥판 구조물의 진동제어를 위한 준능동 TMD의 적용)

  • Kim, Gee-Cheol;Kang, Joo-Won
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.607-612
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    • 2007
  • A conventional passive TMD is only effective when it is tuned properly. In many practical applications, inevitable off-tuning of a TMD occurs because the mass in a building floor could change by moving furnishings, people gathering, etc. When TMDs are off tuned, TMDs their effectiveness is sharply reduced. This paper discusses the application of MR-TMD, semi-active damper, for the reduction of floor vibrations due to machine and human movements. Here, the groundhook and skyhook algorithm are applied to a single degree of freedom system representative of building floors. And displacement and velocity base control method are applied to reduce t100r vibration. The performance of the STMD is compared to that of the equivalent passive TMD. Comparison of the results demonstrates the efficiency and robustness of STMD with respect to equivalent TMD.

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Optimum design of composite steel frames with semi-rigid connections and column bases via genetic algorithm

  • Artar, Musa;Daloglu, Ayse T.
    • Steel and Composite Structures
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    • v.19 no.4
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    • pp.1035-1053
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    • 2015
  • A genetic algorithm-based minimum weight design method is presented for steel frames containing composite beams, semi-rigid connections and column bases. Genetic Algorithms carry out optimum steel frames by selecting suitable profile sections from a specified list including 128 W sections taken from American Institute of Steel Construction (AISC). The displacement and stress constraints obeying AISC Allowable Stress Design (ASD) specification and geometric (size) constraints are incorporated in the optimization process. Optimum designs of three different plane frames with semi-rigid beam-to-column and column-to-base plate connections are carried out first without considering concrete slab effects on floor beams in finite element analyses. The same optimization procedures are then repeated for the case of frames with composite beams. A program is coded in MATLAB for all optimization procedures. Results obtained from the examples show the applicability and robustness of the method. Moreover, it is proved that consideration of the contribution of concrete on the behavior of the floor beams enables a lighter and more economical design for steel frames with semi-rigid connections and column bases.

Effects of balance imagery of semi-tandem stance on a flat floor and balance beam for postural control: a comparison between older and younger adults

  • Lee, Jeong-Weon;Hwang, Sujin
    • Physical Therapy Rehabilitation Science
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    • v.4 no.2
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    • pp.87-93
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    • 2015
  • Objective: Balance is a preceding task for functional activities in daily activities as well as community-dwelling activities. To learn skilled and functional activities, it is also necessary to imagine an appropriate and effective movement representation used to plan and execute the functional activities. The purpose of this study was to evaluate the effects of balance imagery of semi-tandem stance on a flat floor and balance beam on balance abilities for elderly and young adults. Design: Cross-sectional study. Methods: Fifteen elderly and thirty-four young adults were enrolled in this study. In order to determine whether there is a change in postural control ability according to the different imagery training methods used, standing static balance measurements were performed. According to the therapist's instructions, participants were to stand in a semi-tandem position on the Good Balance System for 1 minute while imagining that they were standing on a balance beam, and while the postural control abilities was assessed. Results: Postural control was significantly different in balance ability of semi-tandem stance on a flat floor compared to on a balance beam in both geriatrics and young adults. Postural sway was more significantly decreased in young adults than older adults during balance imagery of semi-tandem stance on a flat floor as well as on balance beam (p<0.05). Conclusions: The results of this study suggest that the ability to mentally represent their actions was similar in older adults compared to young adults, although older adults showed a drop in efficiency of postural control more than young adults.

Application of Semi-active TMD for Floor Vibration Control (바닥판 구조물의 진동제어를 위한 준능동 TMD의 적용)

  • Kim, Gee-Cheol;Kwak, Chul-Seung
    • Journal of Korean Association for Spatial Structures
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    • v.7 no.5
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    • pp.49-56
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    • 2007
  • Passive, active and semi-active control system are classified in floor vibration control system by providing control force. This paper discusses the application of a new class of semi-active TMD(MR-TMD), for the reduction or floor vibrations due to machine and human movements. This MR-TMD consists of passive TMD and MR damper. Here, displacement-based control methods are used to assess the performance of this STMD(MR-TMD). And, skyhook and the groundhook algorithm are applied to a single degree of freedom system representative of building floors. If the allowed operation space of tuned mass is limited in MR-TMD system, skyhook algorithm is more efficient than groundhook algorithm for floor vibration control. Hybrid control method demonstrates the efficiency of MR-TMD with respect to another methods.

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Real-time hybrid simulation of smart base-isolated raised floor systems for high-tech industry

  • Chen, Pei-Ching;Hsu, Shiau-Ching;Zhong, You-Jin;Wang, Shiang-Jung
    • Smart Structures and Systems
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    • v.23 no.1
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    • pp.91-106
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    • 2019
  • Adopting sloped rolling-type isolation devices underneath a raised floor system has been proved as one of the most effective approaches to mitigate seismic responses of the protected equipment installed above. However, pounding against surrounding walls or other obstructions may occur if such a base-isolated raised floor system is subjected to long-period excitation, leading to adverse effects or even more severe damage. In this study, real-time hybrid simulation (RTHS) is adopted to assess the control performance of a smart base-isolated raised floor system as it is an efficient and cost-effective experimental method. It is composed of multiple sloped rolling-type isolation devices, a rigid steel platen, four magnetorheological (MR) dampers, and protected high-tech equipment. One of the MR dampers is physically tested in the laboratory while the remainders are numerically simulated. In order to consider the effect of input excitation characteristics on the isolation performance, the smart base-isolated raised floor system is assumed to be located at the roof of a building and the ground level. Four control algorithms are designed for the MR dampers including passive-on, switching, modified switching, and fuzzy logic control. Six artificial spectrum-compatible input excitations and three slope angles of the isolation devices are considered in the RTHS. Experimental results demonstrate that the incorporation of semi-active control into a base-isolated raised floor system is effective and feasible in practice for high-tech industry.

A Control Method of Semi-active TMD for Vibration Control (진동제어를 위한 준능동 TMD의 제어기법)

  • Lee, Ki-Hak;Kim, Gee-Cheol;Lee, Eun-Suk
    • Journal of Korean Association for Spatial Structures
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    • v.7 no.2
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    • pp.53-61
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    • 2007
  • A conventional passive TMD is only effective when it is tuned properly. In many practical applications, inevitable off-tuning of a TMD occurs because the mass in a building floor could change by moving furnishings, people gathering, etc. When TMDs are offtuned, TMDs their effectiveness is sharply reduced. Moreover, the off-tuned TMs can excessively amplify the vibration levels of the primary structures. This paper discusses the application of a new class of MR damper, for the reduction of floor vibrations duo to machine and human movements. The STMD introduced uses a MR damper called to semi-active damper to achieve reduction in the floor vibration. Here, the STMD and the groundhook algorithm are applied to a single degree of freedom system representative or building floors. The performance or the STMD is compared to that or the equivalent passive TMD. In addition, the effects of off-tuning due to variations in the mass of the floor system. Comparison of the results demonstrates the efficiency and robustness of STMD with respect to equivalent TMD.

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