• Title/Summary/Keyword: Bi-static

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Evaluation of the Balance Ability for 20 to 29 Years Old on the Unstable Platform (불안정 발판(Unstable Platform)에서 20대 연령의 균형능력 평가)

  • Kwon, Oh-Yun;Choi, Houng-Sik
    • Physical Therapy Korea
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    • v.3 no.3
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    • pp.1-11
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    • 1996
  • The purpose of this study were to evaluate and compare the balance ability at different conditions in normal 20 to 29 years old on unstable platform, KAT 2000(Breg, Inc., Vista, CA. 1994). Static and dynamic BI(balance index) were measured 3psi and 5psi surface conditions. Static tests were done on right and left leg separately, then both legs together with the feet apart 20cm with the eyes opened and closed. Dynamic tests were done on both legs together with apart 20cm with the eyes opened. A dynamic test was performed in which the subject moved platform in a circular manner to chase a moving object on a computer screen. Seventy healthy students(average 21.6 years, male, female) were tested. In this study applied the paired t-test and correlation to determine the statistical significance of result. The results were as follow: 1) The mean static balance index of the Rt leg was $119.9{\pm}75.72$ on 3psi surface condition with the eyes opened, and that of the Lt leg was $224.3{\pm}121.16$. 2) The mean static balance index of the Rt leg was $93.1{\pm}24.16$ on 5psi surface condition with the eyes opened, and that of the Lt leg was $180.5{\pm}61.76$. 3) The mean static and dynamic balance index of both legs were $76.4{\pm}31.86$, $2187.6{\pm}696.99$ on 3psi with the eyes opened, and $68.3{\pm}14.82$, $1938.7{\pm}525.41$ on 5psi respectively. 4) The mean static balance index of the Rt leg was $517.8{\pm}220.87$ on 3psi surface condition with the eyes closed, and that of the Lt leg was $588.6{\pm}204.81$. 5) The mean static balance index of the Rt leg was $271.9{\pm}192.151$ on 5psi surface condition with the eyes closed, and that of the Lt leg was $363.4{\pm}98.97$. 6) The mean static balance index of both legs was $332.6{\pm}137.31$ on 3psi surface condition with the eyes closed, and that of the 5psi was $288.5{\pm}133.07$. 7) The balance index on 3psi surface condition was significantly higher than that of 5psi (p<0.05, p<0.01). 8) The balance index with the eyes closed was significantly higher than that of the eyes opened (p<0.05). 9) The balance index on the left leg was significantly higher than that of the right leg (p<0.05, p<0.01). 10) There was no correlation between static balance index and dynamic balance index. 11) Therewas no correlation between weight or height and balance index.

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A Study on Perimeter Load Transfer Fuctions of the Large Diameter Drilled Shafts Depending on Soil Types During the Static Pile Load Tests (정재하시험시 지반종류별 대구경 현장타설말뚝의 주면하중전이함수에 관한 연구)

  • Jung, Ho-Young;Hwang, Seong Chun;Choi, Yongkyu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.5C
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    • pp.163-170
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    • 2011
  • Perimeter load transfer functions were developed by an analysis of the static pile load test results of the 7 large diameter drilled shafts constructed in domestic areas. Using the pile axial load distributions obtained from the static pile load tests of large diameter drilled shafts, the unit skin frictions were analyzed and, based on unit skin friction test data, perimeter load transfer functions could be suggested. The load transfer distributions calculated by suggested functions and the load transfer functions obtained from the bi-directional pile load tests were compared. As a result, the 2 load transfer distributions were coincided, respectively.

Reduction of Horizontal Earth Pressure on Retaining Structures by a Synthetic Compressible Inclusion (압축성재료를 이용한 콘크리트 옹벽의 수평토압 저감방안에 대한 연구)

  • Yoo, Ki-Cheong;Paik, Young-Shik;Kim, Ho-Bi;Kim, Khi-Woong
    • Journal of the Korean GEO-environmental Society
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    • v.4 no.1
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    • pp.19-28
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    • 2003
  • Current methods for lateral thrust calculations are based on the classical formulations of Rankine or Coulomb. However, the previous studies indicate that lateral earth pressures acting on the wall stem, which is the function of deformation parameters of the backfill, are close to the active condition only in the top half of the wall stem and in the lower half of the wall stem, the lateral earth pressures are significantly in excess of the active pressures. This paper presents the compressible inclusion function of EPS which can results in reduction of static earth pressure by accomodating the movement of retained soil. A series of model tests were conducted to evaluate the reduction of static earth pressure using EPS inclusion and determine the optimum stiffness of EPS. Also, field test was conducted to evaluate the reduction of static earth pressure using EPS inclusion. Based on field test it is found that the magnitude of static earth pressure can be reduced about 20% compared with classical active earth pressure.

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Effects of Proprioceptive Neuromuscular Facilitation Relaxation Techniques on Hamstring Flexibility and Vertical Jump Performance (고유수용성신경근촉진법 이완기법이 뒤넙다리근 유연성과 점프수행력에 미치는 영향)

  • Lim, Jae-Heon;Lee, Min-Kook;Park, Jong-Hyuk;Jung, Tae-Ho;Jo, Eun-Bi
    • PNF and Movement
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    • v.13 no.3
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    • pp.135-143
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    • 2015
  • Purpose: The purpose of this study was to assess the effect of the proprioceptive neuromuscular facilitation (PNF) relaxation technique (hold relax; HR, contract relax; CR) and static stretch (SS) on hamstring flexibility and vertical jump performance in healthy adults over a four-week period. Methods: Twenty-four healthy adults volunteered to participate in PNF and static stretch sessions. The subjects were divided into three groups as follows: 8 subjects in the SS group, 8 subjects in the HR group, and 8 subjects in the CR group. In the HR and CR groups, contractions lasted 15 seconds per trial and consisted of 5 sets of 15 seconds of hamstring contraction immediately followed by 15 seconds of passive static hamstring stretching. For the static group, the participants were asked to stretch by hanging a leg over a table for 30 seconds. Subjects in all groups performed the exercises three days per week for 4 weeks. The active straight leg raising (ASLR) test, active knee extension (AKE) test, and vertical jump test were performed before the intervention and after 1, 2, and 4 weeks. Results: The SS, HR, and CR techniques effected positive improvement in hamstring flexibility and vertical jump performances but neither of the stretching methods had any statistically significant different effects according to group, although there were interactions (between group and time) in the ALSR group from 1 week to 2 week and in the AKE test from pretest to 1 week. Conclusion: Based on the results of the current study, SS, HR, and CR were shown to affect hamstring flexibility and vertical jump performance in healthy adults. In particular, it was determined that within a short period, hamstring flexibility could be attributed more to CR than to SS.

Applicability of Bi-directional Load Test for Evaluating Bearing Capacity of Helical Piles (헬리컬 파일의 지지력 산정을 위한 양방향 재하시험의 적용성 평가)

  • Lee, Dongseop;Na, Kyunguk;Lee, Wonje;Kim, Hyung-Nam;Choi, Hangseok
    • Journal of the Korean Geosynthetics Society
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    • v.13 no.4
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    • pp.77-85
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    • 2014
  • The helical pile has become popular with some constructional advantages because relatively compact equipment is needed for installing helical piles. However, field loading tests for estimating the bearing capacity of helical piles have drawbacks that the required dead load should be as much as the operation load, and reaction piles or anchors are required. In this paper, the bi-directional load test without necessity of reaction piles and loading frames was applied to the helical pile, and the load-settlement curves of the helical piles were measured. The bi-directional load test was performed in two separate stages with the aid of a special hydraulic cylinder whose diameter is equal to that of the pile shaft. In the first stage, the hydraulic cylinder is assembled immediately above the bottom helix plate, and the end bearing capacity of the helical pile is measured. In the second stage, the hydraulic cylinder is assembled above the top helix plate, and the skin friction of the helical pile is measured. The pile loading-test program was carried out for the two different helical piles with the shaft diameter of 89 mm and 114 mm, respectively. However, the configuration of helix plates is identical with three helix plates of 450-, 350-, 200- mm diameter. Results of the bi-directional load test were verified by the conventional static pile loading test. As a result, the bearing capacity estimated by the bi-directional load test is in good agreement with the result of the conventional pile loading test.

The Fluxless Wetting Properties of TSM-coated Glass Substrate to the Pb-free Solders (TSM(Top Surface Metallurgy)이 증착된 유리기판의 Pb-free 솔더에 대한 무플럭스 젖음 특성)

  • 홍순민;박재용;박창배;정재필;강춘식
    • Journal of the Microelectronics and Packaging Society
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    • v.7 no.2
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    • pp.47-53
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    • 2000
  • The fluxless wetting properties of TSM-coated glass substrate were evaluated by the wetting balance method. We could estimate the wettability of the TSM with new parameters obtained from the wetting balance test for one side-coated specimen. It was more effective in wetting to use Cu as a wetting layer and Au as a protection layer than to use Au itself as a wetting layer. The SnSb solder showed better wettability than SnAg, SnBi, and SnIn solders. The contact angle of the one side-coated glass substrate to the Pb-free solders could be calculated from the farce balance equation by measuring the static force and the tilt angle.

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A Study on the Development of the Dynamic Photoelastic Hybrid Method for Two Dissimilar Isotropic Bi-Materials (두 상이한 등방성 이종재료용 동적 광탄성 하이브리드법 개발에 관한 연구)

  • Sin, Dong-Cheol;Hwang, Jae-Seok;Gwon, O-Seong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.3
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    • pp.434-442
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    • 2001
  • When the interfacial crack of two dissimilar isotropic bi-materials is propagated with constant velocity along the interface, stress and displacement components are derived in this research. The dynamic photoelastic experimental hybrid method for bimaterial is introduced. It is assured that stress components and dynamic photoelastic hybrid method developed in this research are valid. Separating method of stress component is introduced from only dynamic photoelastic fringe patterns. Crack propagating velocity of interfacial crack is 80∼85% (in case of aluminum, 24.3∼25.9%) of Rayleigh wave velocity of epoxy resin. The near-field stress components of crack-tip are similar with those of pure isotropic material under static or dynamic loading, but very near-field stress components of crack-tip are different from those.

Korean Spatial Information Extraction using Bi-LSTM-CRF Ensemble Model (Bi-LSTM-CRF 앙상블 모델을 이용한 한국어 공간 정보 추출)

  • Min, Tae Hong;Shin, Hyeong Jin;Lee, Jae Sung
    • The Journal of the Korea Contents Association
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    • v.19 no.11
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    • pp.278-287
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    • 2019
  • Spatial information extraction is to retrieve static and dynamic aspects in natural language text by explicitly marking spatial elements and their relational words. This paper proposes a deep learning approach for spatial information extraction for Korean language using a two-step bidirectional LSTM-CRF ensemble model. The integrated model of spatial element extraction and spatial relation attribute extraction is proposed too. An experiment with the Korean SpaceBank demonstrates the better efficiency of the proposed deep learning model than that of the previous CRF model, also showing that the proposed ensemble model performed better than the single model.

Rubber bearing isolation for structures prone to earthquake - a cost effectiveness analysis

  • Islam, A.B.M. Saiful;Sodangi, Mahmoud
    • Earthquakes and Structures
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    • v.19 no.4
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    • pp.261-272
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    • 2020
  • Recent severe earthquakes in and around the vital public places worldwide indicate the severe vulnerability of ground excitation to be assailed. Reducing the effect of seismic lateral load in structural design is an important conception. Essentially, seismic isolation is required to shield the superstructure in such a way that the building superstructure would not move when the ground is shaking. This study explores the effectiveness, design, and practical feasibility of base isolation systems to reduce seismic demands on buildings of varying elevations. Thus, static and dynamic analyses were conducted based on site-specific bi-directional earthquakes for base-isolated as well as fixed-based buildings. Remarkably, it was discovered that isolators used in low-rise to high-rise structures tend to significantly decrease the structural responses of seismic prone buildings. The higher allowable horizontal displacement induces structural flexibility and ensure good structural health of the building stories. Reinforcement from vertical and horizontal members can be reduced in significant amounts for BI buildings. Thus, although incorporating base isolators increases the initial outlay, it considerably diminishes the total structural cost.

Multivariate Congestion Prediction using Stacked LSTM Autoencoder based Bidirectional LSTM Model

  • Vijayalakshmi, B;Thanga, Ramya S;Ramar, K
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.1
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    • pp.216-238
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    • 2023
  • In intelligent transportation systems, traffic management is an important task. The accurate forecasting of traffic characteristics like flow, congestion, and density is still active research because of the non-linear nature and uncertainty of the spatiotemporal data. Inclement weather, such as rain and snow, and other special events such as holidays, accidents, and road closures have a significant impact on driving and the average speed of vehicles on the road, which lowers traffic capacity and causes congestion in a widespread manner. This work designs a model for multivariate short-term traffic congestion prediction using SLSTM_AE-BiLSTM. The proposed design consists of a Bidirectional Long Short Term Memory(BiLSTM) network to predict traffic flow value and a Convolutional Neural network (CNN) model for detecting the congestion status. This model uses spatial static temporal dynamic data. The stacked Long Short Term Memory Autoencoder (SLSTM AE) is used to encode the weather features into a reduced and more informative feature space. BiLSTM model is used to capture the features from the past and present traffic data simultaneously and also to identify the long-term dependencies. It uses the traffic data and encoded weather data to perform the traffic flow prediction. The CNN model is used to predict the recurring congestion status based on the predicted traffic flow value at a particular urban traffic network. In this work, a publicly available Caltrans PEMS dataset with traffic parameters is used. The proposed model generates the congestion prediction with an accuracy rate of 92.74% which is slightly better when compared with other deep learning models for congestion prediction.