• Title/Summary/Keyword: force balance test

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Design of tall residential buildings in Singapore for wind effects

  • Balendra, T.;Ma, Z.;Tan, C.L.
    • Wind and Structures
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    • v.6 no.3
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    • pp.221-248
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    • 2003
  • The design of high-rise building is often influenced by wind-induced motions such as accelerations and lateral deflections. Consequently, the building's structural stiffness and dynamic (vibration periods and damping) properties become important parameters in the determination of such motions. The approximate methods and empirical expressions used to quantify these parameters at the design phase tend to yield values significantly different from each other. In view of this, there is a need to examine how actual buildings in the field respond to dynamic wind loading in order to ascertain a more realistic model for the dynamic behavior of buildings. This paper describes the findings from full-scale measurements of the wind-induced response of typical high-rise buildings in Singapore, and recommends an empirical forecast model for periods of vibration of typical buildings in Singapore, an appropriate computer model for determining the periods of vibration, and appropriate expressions which relate the wind speed to accelerations in buildings based on wind tunnel force balance model test and field results.

The Fluxless Wetting Properties of UBM-Coated Si-Wafer to the Pb-Free Solders (UBM이 단면 증착된 Si-Wafer에 대한 Pb-free 솔더의 무플럭스 젖음 특성)

  • 홍순민;박재용;김문일;정재필;강춘식
    • Journal of Welding and Joining
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    • v.18 no.6
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    • pp.74-82
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    • 2000
  • The fluxless wetting properties of UBM-coated Si-wafer to the binary lead-free solders(Sn-Ag, Sn-Sb, Sjn-In, Sn0Bi) were estimated by wetting balance method. With the new wettability indices from the wetting curves of one side coated specimen, the wetting property estimation of UBM-coated Si-wafer was possible. For UBM of Si-chip, Au/Cu/Cr UBm was better than au/Ni/TI in the point of wetting time/ At general reflow process temperature, the wettability of high melting point solders(Sn-Sb, Sn-Ag) was better than that of low melting point one(Sn-Bi, Sn-In). The contact angle of the one side coated Si-plate to the solder could be calculated from the force balance equation by measuring the static state force and the tilt angle.

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Analysis of Drag Measurements on T-50 Aircraft Model Wind Tunnel Testing (T-50 항공기모델 풍동시험에서의 항력측정 연구)

  • Kim, Hyung-Kook;Yang, Hee-Don;Lee, Il-Woo
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.1564-1568
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    • 2004
  • The requirements of internal balance were studied that should be considered on performing force & moment transonic wind tunnel testing to develop combat aircraft. In many insecure factors of test condition, uncertainty analysis was conducted to verify one drag count measurements. The analysis result was applied to T-50 aircraft model and compared for data verifaction. In conclusion, the aerodynamicist should estimate the validation and accuracy of test data by having an overall grasp of system components including internal balance. It will help him get high productivity of testing and effective validated data at tunnel.

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The effects of EMG activity and blood fatigue makers on balance taping treatment by exercise type (운동형태별 밸런스 테이핑 적용이 EMG 활동 및 혈중 피로물질 반응에 미치는 영향)

  • Lee, Hyo-Seong;Lee, Yong-Sik;Byun, Jae-Chul
    • Korean Journal of Applied Biomechanics
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    • v.14 no.3
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    • pp.271-284
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    • 2004
  • The purpose of this study was to analyse the EMG activity of selected muscles with balance taping treatment and blood fatigue makers which accumulated during exercise of progressive maximal intensity. Ten male college students who did not experience any cardiovascular and musculo-skeletal disease were participated in this study. Balance taping were applied to rectus femoris, vastus medialis, vastus lateralis, biceps femoris, semitendinous, semimembranous, and around knee joint. Isokinetic knee joint flexion/extension force, EMG activity, lactate and ammonia as blood fatigue makers during progressive maximal intensity exercise were measured for with/without applying balance taping. The results indicated that although flexion force of total work at $60^{\circ}/sec$ with taping was increased applied taping did not affect to the aerobic exercise ability parameters. Lactate level as blood fatigue makers during progressive maximal intensity exercise after taping was decreased but the ammonia level did not change with same treatment. In isokinetic knee joint test at the angular velocity of $60^{\circ}/sec$, $180^{\circ}/sec$, and $240^{\circ}/sec$ the taping treatment did not affect to any selected muscle EMG activities except maximal EMG of vastus lateralis at $240^{\circ}/sec$.

Reflectivity of Sn Solder for LED Lead Frame

  • Xu, Zengfeng;Gi, Se-Ho;Park, Sang-Yun;Kim, Won-Jung;Jeong, Jae-Pil
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2011.05a
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    • pp.184-185
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    • 2011
  • In this study, in order to obtain a high reflectivity for the LED lead frame, tin dip coating and tin plating were conducted respectively, and wettability of LED lead frame with tin solder also was tested by wetting balance tester. A Cu sheet was plated in Cu brighten electroplating bath and followed by immersion in a Sn electro-less plating bath [1]. On the other hand, in the dip coating process, a Cu sheet was dipped into molten tin. In the progress of wetting test, besides wetting balance curve, the maximum measured force($F_m$), the maximum withdrawal force($F_w$) and zero-cross time($t_0$) were obtained in various temperatures. With the maximum withdrawal force, the surface tension was calculated at different temperatures. The Cu sheet plated with bright Cu and Sn show a silver bright property while that of Cu dipped with Sn possessed a high reflectance density of 1.34GAM at $270^{\circ}C$.

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Sectional analysis of stamping processes using Equilibrium approach (평형해법에 의한 스탬핑 공정의 단면 해석)

  • Yoon, J.W.;Yoo, D.J.;Song, I.S.;Yang, D.Y.;Lee, J.H.
    • Journal of the Korean Society for Precision Engineering
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    • v.11 no.4
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    • pp.58-68
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    • 1994
  • An equilibrium approach is suggested as an effective tool for the analysis of sheet metal forming processes on the basis of force balance together with geometric relations and plasticity theroy. In computing a force balance equation, it is required to define a geometric curve approximating the shape of the sheet metal at any step of deformation from the geometric interaction between the die and the deforming sheet. Then the geometic informations for contacting and non-contacting sections of the sheet metal such as the number and length of both non-contact region, contact angle, and die radius of contact section are known from the geometric forming curve and utilized for optimization by force balance equation. In computation, the sheet material is assumed to be of normal amisotropy and rigid-phastic workhardening. It has been shown that there are good agreements between the equilibrium approach and FEM computation for the benchmark test example and auto-body panels whose sections can be assumed in plane-strain state. The proposed equilibrium approach can thus be used as a robust computational method in estimating the forming defects and forming severity rather quickly in the die design stage.

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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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The Effect of Gluteus Medius Taping on Balance and Walking in Chronic Stroke Patients (만성 뇌졸중 환자의 마비측 중간볼기근 테이핑이 균형과 보행에 미치는 영향)

  • Lee, Yangjin;Cho, Namjeong
    • Journal of The Korean Society of Integrative Medicine
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    • v.6 no.3
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    • pp.17-24
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    • 2018
  • Purpose : Kinesio taping is a therapeutic method used in the treatment of various musculoskeletal and neuromuscular deficits limited evidence the effects of gluteus medius kinesio taping in neurologic patients. Therefore, this study aimed to determine the effects of gluteus medius kinesio taping on balance ability and gait function in after a stroke. Methods : Twenty-four post-stroke patients were included in this study. Gluteus medius taping group and sham gluteus medius taping group were divided into intervention. Kinesio tape was applied the gluteus medius muscles. In all the subjects, the balance ability was measured using the force plate and timed up & go test (TUG) and gait function was assessed using the 10-meter walking test at time points of both before and after the taping. Result : There was a significant difference in balance ability and gait function between the two groups before and after gluteus medius taping group (p<.05). The gluteus medius taping group showed a significant difference between the groups (p<.05). Conclusion : The results suggest that taping may be a useful method during rehabilitation programs for stroke patients. Application of Kinesio taping to the gluteus medius muscles was found to be useful especially in improving balance ability.

Analysis Software based on Center of Pressure to Improve Body Balance using Smart Insole

  • Moon, Ho-Sang;Goo, Se-Jin;Byun, Sang-Kyu;Shin, Sung-Wook;Chung, Sung-Taek
    • International journal of advanced smart convergence
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    • v.9 no.1
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    • pp.202-208
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    • 2020
  • Body balance necessary for ordinary daily activities can be undermined by diverse causes. In this study, as a way to control such a problem, we have produced smart insole as a wearable device in the form of insole and developed analysis software evaluating body balance, which measures ground reaction force applied to each area of sole and Center of Pressure (COP). The software visualized changes in COP positions while a user was moving and average COP positions, and it is also capable of measuring the COP values in the Anterior-Posterior (AP) and Medial-Lateral (ML) areas of feet. Through gait analysis, it can analyze the time of walking, strides, speed, COP trajectory while walking, etc. In addition, we have developed training contents for body balance improvement designed in consideration of Y-Balance Test and Timed Up and Go (TUG) Test. They were established in virtual reality similar to daily living environment so that people can expect more effective training results regardless of places.

A Study on the Sail Force Prediction Method for Hull Hydrodynamic Force Measurement of 30feet Catamaran Sailing Yacht (30ft급 쌍동형 세일링 요트의 선체 유체력 계측에 의한 세일력 추정방법에 관한 연구)

  • Jang, Ho-Yun;Park, Chung-Hwan;Kim, Hyen-Woo;Lee, Byung-Sung;Lee, In-Won
    • Journal of the Society of Naval Architects of Korea
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    • v.47 no.4
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    • pp.477-486
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    • 2010
  • During sailing by wind-driven thrust on the sail, a catamaran sailing yacht generates leeway and heeling. For predicting sail force, a model test was carried out according to running attitude. Through the model test, drag and side force of the real ship was predicted. A purpose of this study is to find sail force to C.E from changed attitude during running direction. By balance of hull and sail, a heeling force of designed sail is predicted. Also through heeling force and driving force, total sail force and direction from C.E are considered with changed mast including leeway and heeling.