• 제목/요약/키워드: Forward Reaction

검색결과 153건 처리시간 0.023초

초등학교 학생들의 발달단계에 따른 던지기 동작의 운동역학적 분석 (The Biomechanical Analysis of Throwing Motion for the Elementary Students - Developmental Approach -)

  • 이동우
    • 한국운동역학회지
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    • 제17권1호
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    • pp.69-79
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    • 2007
  • The purpose of this study was to examine the characteristics of throwing motion in the elementary school students from the developmental point of view. For the purpose of this, total of nine subjects(each of three students in five, third, and first grades) were participated. They were asked to throw the ball as far as they can and the motions were videotaped with the 30frames/sec and 1/500 shutter speed. The successful motions for each subject were selected for three dimensional analysis. The collected data were analyzed using DV express 1.0 and Kwon3D 3.0 softwares. The results obtained from this study were as follows; 1. Total time for the throwing motion of the first grade was longer than that of the fifth and third grades. 2. The resultant displacement and velocity of COM for the fifth and third grades were greater than that of the frist grade. 3. The first grade tended to flex the trunk forward excessively during the throwing motion. 4. The fifth grade tended to place the upper arm close to the sagital plane and move the forearm and hand freely. 5. Looking at the greater variability of the angular velocity of the hand segment, the fifth grade seemed to have faster and more flexible movement of the wrist. 6. There were somewhat differences in the patterns and magnitudes of ground reaction forces among the different grades.

AFO Changes Leg Muscle Activation During Stairs Descending

  • Choi, Jae Cheong;Han, Seul Ki
    • 국제물리치료학회지
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    • 제7권2호
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    • pp.1037-1040
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    • 2016
  • This study aims to investigate the effects of ankle foot orthosis(AFO) on the activities of tibialis anterior(TA), soleus(Sol), rectus femoris(RF) and biceps femoris(BF) during stairs descending. The activities of TA, Sol, RF and BF were initially measured while descending 4 stairs without using AFO. The activities of the same muscles were then measured again while descending 4 stairs while using AFO. Wilcoxon signed-rank tests were used to analyze the results in order to examine the differences between the with using AFO and without using AFO. Although the activities of TA, Sol and RF were relatively lower while using AFO than without using AFO, only the differences in Sol and RF activities were significant(p<0.05). The activity of BF was relatively higher while using AFO compared to the activity of BF observed without using AFO. However, difference was not significant(p>0.05). Conclusion of this study was observed since AFO's ground reaction force absorption during stairs descending reduced the need to use So and RF that is related to shock absorption. BF activity was increased with AFO than without during standing forward to correct the trunk stability.

노후터널의 운영중 터널확대시 지반종단변형특성에 관한 연구 (Longitudinal Deformation Characteristics during Excavation of a old Tunnel in Operation)

  • 백기현;김웅구;서경원;유동우
    • 한국지반공학회논문집
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    • 제27권11호
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    • pp.47-54
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    • 2011
  • 본 논문에서는 다양한 조건에 대한 터널의 종단변형특성을 분석하여 터널확대 시 종단변형곡선을 제안하였으며 이를 이용하여 최종적으로 프로텍터 보호범위에 대해 고찰해 보았다. 이를 위해 지반물성 및 확대조건별 수치해석을 실시하였으며 터널 확대 조건이 종단변형에 미치는 영향을 파악하여 터널확대 시 적합한 지반종단변형곡선식을 제안하였다. 또한 제안한 종단변형곡선식을 이용하면 2차로 터널을 4차로 확대 시 프로텍터 보호범위는 막장 후방 약 24m, 막장 전방 약 35m를 보호해야 할 것으로 판단된다.

유기박막의 제작방법에 따른 표면구조에 관한 연구 (A Study on the Surface Structure by Fabrication Method of Organic Thin Film)

  • 최영일;김병근;전동규;김영근;이경섭
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 하계학술대회 논문집 C
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    • pp.1580-1582
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    • 2003
  • Transformation of molecular film occurs only usually in air-water interface, 2 dimensions domain's growth and crash are achieved. Organic thin film that consist of growth of domain can understand correct special quality of accumulation film supplying information about fine structure and properties of matter of device observing information and so on that is surface forward player and optic enemy using AFM one of SPM application by nano electronics. In this paper Langmuir (L) that is one of basis technology to manufacture of organic matter device using Biology material PBDG that is kind of polypeptide that have Biology adaptedness. Detected of accumulation condition in observing Surface Pressure change by stimulus reaction of Langmuir (L) and Spin-Coating film. Therefore AFM by this confirm and compared.

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고등학교 야구 포수의 2루 송구 동작에 대한 운동역학적 분석 (Biomechanical Analysis of Throw Movement to Second Base in High School Elite Baseball Catchers)

  • Kim, Sung Yong;Park, Jong Chul;Byun, Kyung Seok;Baek, Hee Young
    • 한국운동역학회지
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    • 제30권2호
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    • pp.165-172
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    • 2020
  • Objective: The purpose of this study was to provide quantitative and objective data of throwing movement in baseball catcher through biomechanical analysis. Method: Eight high school baseball catchers (age: 17.3±0.7 yrs, height: 175.3±4.5 cm, weight: 82.5±9.0 kg, Career: 7.4±2.1 yrs) participated and 3-dimentional motion capture system and electromyography (EMG) were used in this study. Results: The maximum center of mass position displacement was observed in forward direction. The linear velocity magnitude of the upper extremity segments were showed as "wrist>elbow>shoulder" which is indicative of kinematic chain. For kinetic EMG data, we also observed the greater muscle activation in the left brachioradial and erector spine muscles muscle that during throwing movement. Conclusion: We expect that biomechanical data from this study will provide important training implications to baseball coaches and trainers in order to effectively train their baseball catchers.

수처리 콘크리트 구조물의 부력모멘트에 대한 안정성 검토 (Stability Review on Buoyancy Moment in the Water Treament Concrete Structure)

  • 심의전
    • 대한토목학회논문집
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    • 제41권3호
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    • pp.327-330
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    • 2021
  • 수처리 콘크리트 구조물과 건축 구조물 설계시 일반적으로 부력의 안정성 검토는 행해지고 있으나, 고정하중의 중심과 부력의 중심 사이의 편심으로 인한 부력모멘트에 대한 안정성 검토는 행해지지 않고 있다. 본 검토에서는 부력이 커짐에 따라 고정하중(W)과 부력(B)의 합력의 작용점과 반력분포를 고찰하여 부력모멘트 회전지점의 형성을 규명함으로써 수처리콘크리트구조물과 건축 구조물의 부력모멘트에 의한 회전부상 안전율식을 도출하여 부력모멘트에 대한 안정성 검토방법을 제시하였다.

MRI-Guided Gadolinium Neutron Capture Therapy

  • Ji-Ae Park;Jung Young Kim;Hee-Kyung Kim
    • 대한방사성의약품학회지
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    • 제8권2호
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    • pp.113-118
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    • 2022
  • Gadolinium neutron capture therapy (Gd-NCT) is a precision radiation therapy that kills cancer cells using the neutron capture reaction that occurs when 157Gd hits thermal neutrons. 157Gd has the highest thermal neutron capture cross section of 254,000 barns among stable isotopes in the periodic table. Another stable isotope, 155Gd, also has a high thermal neutron trapping area (~ 60,700 barns), so gadolinium that exists in nature can be used as a Gd-NCT drug. Gd-NCT is a mixed kinetic energy of low-energy and high-energy ionizing particles, which can be uniformly distributed throughout the tumor tissue, thereby solving the disadvantage of heterogeneous dose distribution in tumor tissue. The Gd complexes of small-sized molecule are widely used as contrast agents for magnetic resonance imaging (MRI) in clinical practice. Therefore, these compounds can be used not only for diagnosis but also therapy when considering the concept of Gd-NCT. This multifunctional trial can look forward to new medical advance into NCT clinical practices. In this review, we introduce gadolinium compounds suitable for Gd-NCT and describe the necessity of image guided Gd-NCT.

화염 구조에 미치는 연료 및 당량비에 관한 연구 (A Study on the Influence of Equivalence Ratio and Kinds of fuel in Flame Structure)

  • 박상규;최낙정;산하박사
    • 한국분무공학회지
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    • 제3권4호
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    • pp.43-49
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    • 1998
  • In order to clarify the effect of equivalence ratio and kinds of fule in flame structure, a numerical simulation of triple flame developed in a co-flowing methane-air and air stream was carried out by the elementary chemical reaction mechanism. The following conclusions were obtained. Equivalence ratio at which the apparent burning velocity is maximum is a little larger than that of the one-dimensional premixed flame. Apparent burning velocities are two times higher than that of the one-dimensional premixed flame for the methane-air. The flame thrusts out forward in the downstream of the boundary between mixture and air stream, and a part of the flow is bent and forks out in this protruding flame so that a triple flame is originated; this triple flame is composed of fuel rich and lean premixed flame branches and a diffusion flame branch. Near the equivalence ratio at which the burning velocity of rule-dimensional premixed flame is the largest the effect of one-dimensional premixed flame becomes large and the fuel rich premixed flame advances and becomes vertical to the flow direction.

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Performance of Cu-SiO2 Aerogel Catalyst in Methanol Steam Reforming: Modeling of hydrogen production using Response Surface Methodology and Artificial Neuron Networks

  • Taher Yousefi Amiri;Mahdi Maleki-Kakelar;Abbas Aghaeinejad-Meybodi
    • Korean Chemical Engineering Research
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    • 제61권2호
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    • pp.328-339
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    • 2023
  • Methanol steam reforming (MSR) is a promising method for hydrogen supplying as a critical step in hydrogen fuel cell commercialization in mobile applications. Modelling and understanding of the reactor behavior is an attractive research field to develop an efficient reformer. Three-layer feed-forward artificial neural network (ANN) and Box-Behnken design (BBD) were used to modelling of MSR process using the Cu-SiO2 aerogel catalyst. Furthermore, impacts of the basic operational variables and their mutual interactions were studied. The results showed that the most affecting parameters were the reaction temperature (56%) and its quadratic term (20.5%). In addition, it was also found that the interaction between temperature and Steam/Methanol ratio is important on the MSR performance. These models precisely predict MSR performance and have great agreement with experimental results. However, on the basis of statistical criteria the ANN technique showed the greater modelling ability as compared with statistical BBD approach.

Research of 3D image processing of VR technology in medicine based on DNN

  • ZhaoZhe, Gong;XiaoDong, Li;XiaoYing, Shi;Geng, Liu;Bin, Chen
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제16권5호
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    • pp.1584-1596
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    • 2022
  • According to a survey published in an authoritative journal in January 2020, the globalincidence rate of mental illness is 8.3% for men and 10.6% for women, which indicates thatmental illness has become a globally recognized obstacle. Therefore, specific psychotherapy including mental illness will become an important research topic. It is very effective forpatients with special mental diseases, such as mental illness, to reduce their mental reaction byexposure therapy; the system uses the virtual reality system of medical images processed by learningalgorithm to reproduce the effect of virtual reality exposure method of the high scene of transparent ladder. Compared with the old invasive exposure scene, the results show that theimprovement of both conditions has obvious effect, and the effect of human treatment underthe two conditions is not good. There are obvious differences, which show that virtual reality model will gradually replace the on-the-spot feeling. Finally, with more and more researchers have put forward a variety of other virtual reality image processing models, the research of image processing has gradually become more and more interested.