• Title/Summary/Keyword: holding force

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Compatible Anchors of Silt Protector in Shallow Sea with Mud Seafloor Material (천해역 점성토 지반에 적합한 오탁방지막 기초 앵커)

  • KWEON GI-CHUL;HONG NAM-SEEG;SONG Mu-HYO;CHOI CHANG-GYU
    • Journal of Ocean Engineering and Technology
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    • v.17 no.3 s.52
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    • pp.7-12
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    • 2003
  • The Navy has tested the holding capacity of many kinds of anchors in order to propose the design chart for the holding capacity of drag-embedment anchors. The design chart is only applicable up to the cable bottom angle 60 when load is raised to the ultimate weight. However, the anchor experiences a significant uplift force when the angle is above 60 in shallow seas. In this paper, the procedure for the estimation of the holding capacity of anchors in mud is proposed. Drag-embedment anchors do not function well when there is a significant uplift component of load in soft seafloor materials, such as mud. Under these loading and seafloor conditions, gravity anchors seems to be more efficient. However, they are too heavy for their holding capacity. Therefore, suction pile (hollow concrete block) is more beneficial to the foundntion of silt protector in shallow sea with mud seafloor materials.

Analysis of the Ground Reaction Force of Arm Landing during Sports Aerobics (스포츠 에어로빅스 팔착지 동작의 지면 반력 분석)

  • Yoo, Sil
    • Korean Journal of Applied Biomechanics
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    • v.12 no.1
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    • pp.115-124
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    • 2002
  • The purpose of this study is to analyze the ground reaction force of arm landing on arm and leg during sports aerobics. Subjects of this study were total 10 players of 5 males and 5 females who have are domain sports aerobics medalists more than the third place in national tournaments. The subjects jumped between the two ground reaction force analyzers, while landing their right hand on the front platform(#1) and their right leg on the rear platform(#2), and the data frequency was set to 200Hz. Findings of this study are as follows; More than 3 times of impact peak force of vertical reaction force acted on arm joint than on leg joint. And, when ground reaction force on foot increased, ground reaction force on hand decreased. 3 impact peaks of curve of ground reaction force were found - Impact Peak 1 incurred on the time the palm lands on the ground, Impact Peak 2 absorbing shock secondarily on wrist joint, and Active Peak incurred on the time of holding the weight while pushing out the severly bent elbow joint.

Evaluation of Meat Color and Physiochemical Characteristics in Forequarter Muscles of Holstein Steers

  • Moon, Sung Sil;Seong, Pil-Nam;Jeong, Jin Young
    • Food Science of Animal Resources
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    • v.35 no.5
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    • pp.646-652
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    • 2015
  • The beef forequarter muscle comprises approximately 52% of carcass weight. The objective of this study was to evaluate the physiochemical characteristics and meat color from forequarter muscle of Holstein steers. Fifteen forequarter muscles were trimmed of external connective tissue and fat. An experimental group of eight Holstein steers was assessed using meat color, water-holding capacity, drip loss, and Warner-Bratzler shear force value at the same quality grade. The M. omotransversarius (0.45 kg) had the highest (p<0.05) lightness (L*) value, whereas the M. teres major (0.4 kg) and M. triceps brachii (caput laterale) (0.52 kg) had the lowest (p<0.05) values. The M. semispanitus capitus (1.48 kg), which is a neck muscle, had the highest values for both redness (a*) and yellowness (b*), whereas the lowest (p<0.05) values were for the M. teres major. The M. omotransversarius, M. latissimus dorsi (1.68 kg), and M. rhomboideus (1.2 kg) were ranked high (p<0.05) in water-holding capacity. The drip loss value was the highest for the M. longissimus dorsi thoracis (p<0.05; 1.86 kg), while the M. infraspinatus (2.28 kg), M. supraspinatus (1.38 kg), M. brachiocephalicus (1.01 kg), and M. pectoralis superficialis (1.18 kg) had the lowest (p<0.05). The Warner-Bratzler shear force value indicated that the M. pectoralis profundus (3.39 kg), M. omotransversarius, and M. brachiocephalicus were the toughest (p<0.05), whereas the M. subscapularis (0.86 kg), M. longissimus dorsi thoracis, M. teres major, and M. infraspinatus were the most tender cuts (p<0.05). Here, muscle type explained most of the variability in the forequarter physiochemical characteristics. Thus, our findings suggest that these muscle profile data will allow for more informed decisions when selecting individual muscles to produce value-added products from Holstein steers.

Analytical Study on Dynamic Characteristics of Hydraulic Cylinder Applied to the Vehicle Holding Device for Launch Vehicle (발사체용 지상고정장치 구동유압실린더의 운동특성에 관한 해석적 연구)

  • Lee, Jaejun;Park, Sangmin;Yang, Seongpil;Kim, Daerae
    • Journal of the Korean Society of Propulsion Engineers
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    • v.21 no.1
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    • pp.44-50
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    • 2017
  • Vehicle Holding Device(VHD) has a role that holding the launch vehicle on its launch pad until the engine therust reaches a steady condition. The analytical study of shape parameters and dynamic characteristics of hydraulic cylinders is carried out. The contraction of cylinder is considered as the major factor of releasing mechanism. Through the analysis, the decreasing of cylinder slit size and increasing initial charging pressure increase the contraction force. Through the transient analysis, cylinder load, displacement and inner pressure distribution are confirmed. The cylinder contraction force is converged to the cylinder external force when the cylinder starts to move. Also, the pressure distribution in the hydraulic cylinder is constant.

Evaluation of the Springback Characteristics for Automotive Steel Sheets by the S-Rail Forming Test (S-레일 시험을 통한 자동차용 판재의 스프링백 특성 평가)

  • Kwon, ln-Jae;Rim, Jae-Kyu;Kim, Hyung-Jong
    • Journal of Industrial Technology
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    • v.21 no.B
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    • pp.287-294
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    • 2001
  • This study is aimed to evaluate the springback characteristics of automotive steel sheets through the S-rail forming test and to find the process condition under which springback can be reduced. Die set for the S-rail test has been made according to the dimension of the NUMISHEET '96 benchmark model. Experiment and finite element analysis have been performed on two kinds of automotive steel sheets: mild steel, SPCEN and high strength steel, SPRC. The test results show that the amount of springback is larger on the high strength steel SPRC than on the mild steel SPCEN, and decreases with increasing blank holding force as the case of material flow. And the reduction of friction has the effect of lowering the blank holding force in view of punch force and material flow. It is shown that the strain distribution over the whole specimen and along the specified sections calculated from the finite element analysis coincides with the measured data except local differences.

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The Biomechanical Analysis of a One-Legged Jump in Traditional Korean Dance According to Breathing Method (호흡 방법에 따른 한국무용 외발뛰기 동작의 운동역학적 분석)

  • An, Ju-Yeun;Yi, Kyung-Ock
    • Korean Journal of Applied Biomechanics
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    • v.25 no.2
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    • pp.199-206
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    • 2015
  • Objective : The purpose of this study was to conduct a biomechanical analysis of a one-legged jump in a traditional Korean dance (Wae Bal Ddwigi) according to breathing method. Method : Participants for this study were 10 dancers with experience for at least 10 years in traditional Korean dance. Independent variables for this test were two different types of breathing methods. Dependent variables were ground reaction force and lower extremity kinematic variables. The jumping movement was divided into three separate stages, take off, flight, and landing. The subjects were asked a questionnaire regarding the degree of impact force and stability of landing posture after the experiment. The Kistler Force Plate (9281B, Switzerland) was used to measure ground reaction force. A digital camera was used to look into angles of each joint of the lower part of body. SPSS was used for statistical analysis via the dependent t-test(p<.05). Results : There were significant differences in jumping according to breathing method. The inhalation & exhalation method yielded significantly longer flight times combined with greater ground reaction force. The breath-holding method required more core flexion during landing, increasing movement at the hips and shoulders. Conclusion : Consequently, there was more flexion at the knee to compensate for this movement. As a result, landing time was significantly higher for breath-holding.

Internal force monitoring design of long span bridges based on ultimate bearing capacity ratios of structural components

  • Hu, Ke;Xie, Zheng;Wang, Zuo-Cai;Ren, Wei-Xin;Chen, Lei-Ke
    • Structural Monitoring and Maintenance
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    • v.5 no.1
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    • pp.93-110
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    • 2018
  • In order to provide a novel strategy for long-span bridge health monitoring system design, this paper proposes a novel ultimate bearing capacity ratios based bridge internal force monitoring design method. The bridge ultimate bearing capacity analysis theories are briefly described. Then, based on the ultimate bearing capacity of the structural component, the component ultimate bearing capacity ratio, the uniformity of ultimate bearing capacity ratio, and the reference of component ultimate bearing capacity ratio are defined. Based on the defined indices, the high bearing components can then be found, and the internal force monitoring system can be designed. Finally, the proposed method is applied to the bridge health monitoring system design of the second highway bridge of Wuhu Yangtze river. Through the ultimate bearing capacity analysis of the bridge in eight load conditions, the high bearing components are found based on the proposed method. The bridge internal force monitoring system is then preliminary designed. The results show that the proposed method can provide quantitative criteria for sensors layout. The monitoring components based on the proposed method are consistent with the actual failure process of the bridge, and can reduce the monitoring of low bearing components. For the second highway bridge of Wuhu Yangtze river, only 59 components are designed to be monitored their internal forces. Therefore, the bridge internal force monitoring system based on the ultimate bearing capacity ratio can decrease the number of monitored components and the cost of the whole monitoring system.

A study of rippleless thrust force control for LPM (LPM의 추력리플 저감 기법 개발)

  • Kim, Moon-Hwan;Kim, Kook-Hun;Ha, In-Joong;Ko, Yo
    • Proceedings of the KIEE Conference
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    • 1996.07a
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    • pp.358-360
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    • 1996
  • LPM(Linear pulse motor) has made linear motions by itself. And the LPM has higher thrust force ratio to mass and more wide driving speed lunges comparing with the conventional rotating type motors. However, there are the thrust force ripples in the LPM, which are produced by the mechanical structures and nonlinear back emf. It makes to hesitate the practical applications of LPM. Especially, it becomes needed to reduce the thrust force ripples for practical, which needs relative low driving speeds. For reducing the thrust force ripples, in the first place, it was built a new nonlinear linkage flux equations of the LPM. In these equations, the influence of permanent magnetic and variable reluctance thrust force components were considered. In this paper, some experimental results in the modeling of LPM are shown and detent lone and holding force characteristics of LPM are measured.

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Synthesis of Acrylic Nonionic Reactive Emulsifier with Aromatic Ring and the Properties of Water-based Acryl Pressure Sensitive Adhesive (방향족 고리를 가지는 아크릴계 비이온 반응성 유화제 합성 및 이를 이용한 수성 점착제 물성 연구)

  • Yeom, Do-Young;Kim, Dong Hwan;Hwang, Gaeun;Hwang, Do-Hoon;Jung, Yu Jin
    • Journal of Adhesion and Interface
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    • v.22 no.2
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    • pp.31-38
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    • 2021
  • In this study, a nonionic reactive emulsifier with aromatic and acryl group was synthesized by using polyoxyethylene(10) dodecylphenyl ether with 3-butenoic acid. The synthesized nonionic reactive emulsifier was confirmed by 1H-NMR and FT-IR. In addition, the reactive emulsifier synthesized in the preparation of aqueous acrylic adhesives base emulsion was used and the properties of the solid content, conversion, particle size distribution, peel strength and high temperature holding force were compared to those of nonionic emulsifiers without aromatic group. The particle size was distributed from 370 nm to 698 nm, and the peel strength were measured in the range of 1.507~1.802 kgf. The high temperature holding force of prepared adhesives base emulsion were measured in the range of 0.50~2.00 mm. Especially, in the result of synthesized nonionic reactive emulsifier with aromatic group, it was confirmed that high temperature holding force results were the most excellent than the case of using other nonionic reactive emulsifiers, and it can be useful for water-based acryl pressure sensitive adhesive.

Functional Verification of Engineering Model of Non-explosive Shockless Holding and Release Mechanism Using Heating Wire Cutting Method (열선 절단 방식을 적용한 비폭발식 무충격 구속분리장치 EM의 기능검증)

  • Oh, Hyun-Ung;Jeon, Su-Hyeon
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.23 no.5
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    • pp.401-406
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    • 2013
  • Non-explosive shockless holding and release mechanism for a nano class small satellite application has been proposed and investigated. The great advantages of the mechanism are a much lower shock level and larger constraint force than the conventional mechanism using pyro and the heating wire cutting mechanism which has been generally applied to the cube satellite program. To investigate the effectiveness of the mechanism design, EM mechanism was developed and tested to verify the basic function of the mechanism. The test results indicate that the proposed mechanism is well functioning as the mechanism design intends.