• Title/Summary/Keyword: impact position

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Kinematic Analysis of Service Movement In Each Position of Soft Tennis (포지션별 정구 플랫서비스의 운동학적분석)

  • Kim, Hun-Soo
    • Korean Journal of Applied Biomechanics
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    • v.12 no.1
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    • pp.221-231
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    • 2002
  • The purpose of this study was to clarify the differences in service patterns of a forward and backward soft tennis players using 3D motion analyzer. Subjects were 4 forward players of $24.0\pm5.23$yrs and 4 backward players of $23.5\pm1.73$yrs. The results were as following: 1. There was no difference among each positions on swinging-time. The longest racket swinging-time was in the phase of takeback, the second one was in follow-through. The shortest one was in the phase of forward-swing so called force production phase, which had an influence on ball's velocity. 2. The racket speed on impact was 16.3m/s in forward subject and 19.53m/s in backward subject, when each velocity of balls was 44.6m/s, 52.9m/s. Although there was no significant difference along by positions, backward subject showed faster result. 3. The maximum speed of each performance was reached before the impact, and the speed at impact along by positions did not show any significant difference. The summation of velocity was measured in good order as following; hip, shoulder, elbow, wrist, top of racket. 4. In the angular velocity of all examine except one, the angular velocity of forearm was bigger than the one of racket top although there was no statistically significant difference between forward and backward subject. 5. The service grip of the forward players was shorter than that of backward players.

The Impact of the Well-being Trend and Attributes of Choice for Walnut-cookie on Purchase Intention (웰빙트렌드와 호두과자 선택속성이 소비자 구매의도에 미치는 영향)

  • Min, Kyung-Mook;Ha, Kyu-Soo
    • Journal of Families and Better Life
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    • v.26 no.6
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    • pp.193-207
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    • 2008
  • This study analyzed the impact of the well-being trends and the attributes of the choice of the walnut-cookie on the consumer's purchasing intention. The results of this study would enhance newly revised product so that brand and product marketing strategy would be strengthened. This study also would contribute for the consumer related management through systematic and exploring research regarding consumers' expectation of products' values and trends. Specific results are as followings. Well-being oriented trends had various meanings such as "Commercial Well-being", "Eco-friendly Well-being", "Physical Well-being", and " Favors for leisure". Consumer's attributes of choice for the walnut-cookie were "Branding", "The Value of Traditional Food", "Environmental Position", and "The Function of Products". And the "Popularity", "Nutrition". and the "Service" were most preferred factors to be chosen. The multiple regression analysis was tried to test the impact of demographics, well-being trend, and the attributes of choice for walnut-cookie influence on the consumer's purchasing intention. The statistically significant factors were age, job, and leisure oriented consumer style of consumer's characteristics as well as corporation's brand strategy on a basis of marketing aspects. The younger groups, leisure pursing groups, and student groups showed the higher level of purchasing intention for the walnut-cookie compared to other groups.

Design and Performance Evaluation of a 3-DOF Mobile Microrobot for Micromanipulation

  • Park, Jungyul;Kim, Deok-Ho;Kim, Byungkyu;Kim, Taesung;Lee, Kyo-Il
    • Journal of Mechanical Science and Technology
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    • v.17 no.9
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    • pp.1268-1275
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    • 2003
  • In this paper, a compact 3-DOF mobile microrobot with sub-micron resolution is presented. It has many outstanding features : it is as small as a coin ; its precision is of sub-micrometer resolution on the plane ; it has an unlimited travel range ; and it has simple and compact mechanisms and structures which can be realized at low cost. With the impact actuating mechanism, this system enable both fast coarse motion and highly precise fine motion with a pulse wave input voltage controlled. The 1 -DOF impact actuating mechanism is modeled by taking into consideration the friction between the piezoelectric actuator and base. This modeling technique is extended to simulate the motion of the 3-DOF mobile robot. In addition, experiments are conducted to verify that the simulations accurately represent the real system. The modeling and simulation results will be used to design the model-based controller for the target system. The developed system can be used as a robotic positioning device in the micromanipulation system that determines the position of micro-sized components or particles in a small space, or assemble them in the meso-scale structure.

Nonlinear Dynamic Buckling Behavior of a Partial Spacer Grid Assembly

  • Yoon, Kyung-Ho;Kang, Heung-Seok;Kim, Hyung-Kyu;Song, Kee-Nam;Jung, Yeon-Ho
    • Nuclear Engineering and Technology
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    • v.33 no.1
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    • pp.93-101
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    • 2001
  • The spacer grid is one of the main structural components in the fuel assembly, which supports the fuel rods, guides cooling water, and protects the system from an external impact load, such as earthquakes. Therefore, the mechanical and structural properties of the spacer grids must be extensively examined while designing them. In this paper, a numerical method for predicting the buckling strength of spacer grids is presented. Numerical analyses on the buckling behavior of the spacer grids are performed for a various array of sizes of the grids considering that the spacer grid is an assembled structure with thin-walled plates and imposing proper boundary conditions by nonlinear dynamic finite element method using ABAQUS/Explicit. Buckling tests on several numbers of specimens of the spacer grid were also carried out in order to compare the results between the test and the simulation result. The drop test is accomplished by dropping a carriage on the specimen at a pre-determined position. From this test, the specimens are buckled only at the uppermost and the lowermost layer among the multi-cells, which is similar to the local buckling at the weakest point of the grid structure. The simulated results also similarly predicted the local buckling phenomena and were found to give good correspondence with the experimental values for the thin-walled grid structures.

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Measurement Method of Airburst Height Using the Approach Angle (비행체 진입각을 이용한 공중 폭발고도 계측 방법)

  • Kim, Jinho
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.4
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    • pp.497-504
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    • 2017
  • This paper proposes a method to measure the airburst height by utilizing a high speed camera. This method might be applied to the test of which flight target is alive after the burst. The proposed method consists of four main steps. The first step is to compute the impact point using the sea surface height. The second step is to compute the height of burst (HOB) by using the distance from the camera to the impact point. This could be different from the real explosion height. That is because the distance from the camera to the burst point is not the same as it from the camera to the impact point. Therefore, the third step is to calculate the approach angle of the flight target with respect to the installed camera. Then, the last step is to compensate the computed height by using the approach angle. The result of the proposed method is compared with it from the triangulation. In this paper, the HOB error is also analyzed regarding the approach angle difference. Based on this analysis, the camera position might be suggested for error reduction.

Financial Literacy, Network Competency, and SMEs Financial Performance: The Moderating Role of Market Orientation

  • ALI, Hazem;LI, Yanchao
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.10
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    • pp.341-352
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    • 2021
  • Research on SMEs highlights their limited resources and the influential role of SMEs' owners/managers. In this respect, scholars stressed the importance of different capabilities possessed by owners/managers of SMEs in developing a competitive position and enhancing firm performance. This study intended to examine the direct influence of two fundamental capabilities: financial literacy and networking competency possessed by owners/managers of SMEs in China and the United Arab Emirate (UAE) on SMEs' financial performance. In addition, this research tested the moderating impact of market orientation. The quantitative research method was employed by administering structured questionnaires. A total of 150 and 120 questionnaires were collected from owners/managers of SMEs in China and UAE. Structural equation modeling was used for data analysis using Smart-Pls. Findings revealed that SMEs' financial performance was positively related to maintaining financial literacy and networking competency in both samples. Further, market orientation was found to strengthen the positive impact of financial literacy and networking competency on SMEs' financial performance in China. However, market orientation had a significant moderating impact only on the relationship between networking and the financial performance of SMEs in the UAE. This paper ends with providing a set of concluding remarks, recommendations, and potential areas of further research.

Globalization and Foreign Direct Investment in the GCC Countries: A Recipe for Post COVID-19 Recovery

  • MODUGU, Kennedy Prince;DEMPERE, Juan
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.9
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    • pp.11-22
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    • 2021
  • This study investigates the long-run relationship between the de jure economic, political, and social globalization and foreign direct investments in the Gulf Cooperation Council (GCC) to establish whether policies that foster trade and investment relations among geographical entities can help revive the GCC countries from the prevailing economic debacles of the COVID-19 pandemic. This study is driven by the GCC's quest to fully overcome the economic challenges occasioned by the outbreak of the global pandemic and position itself as the most potent regional economic bloc in the Middle East and North Africa (MENA) region. The study employs the panel data of the six GCC countries of Bahrain, United Arab Emirates, Kuwait, Qatar, Oman, and Saudi Arabia from 1971 to 2017. The findings of the panel fully modified ordinary least square regression estimation show that the de jure economic and social globalization have a significant positive impact on the region's foreign direct investment inflows. The impact of the de jure political globalization on foreign direct investment is statistically significant but negatively signed. Based on the preceding findings, we offer some holistic policy recommendations to the GCC region as recipes for timely recovery from the economic impact of COVID-19 and beyond.

A COG Variable Analysis of Air-rolling-breakfall in Judo (유도 공중회전낙법의 COG변인 분석)

  • Kim, Eui-Hwan;Chung, Chae-Wook;Kim, Sung-Sup
    • Korean Journal of Applied Biomechanics
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    • v.15 no.3
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    • pp.117-132
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    • 2005
  • It was to study a following research of "A Kinematic Analysis of Air-rolling-breakfall in Judo". The purpose of this study was to analyze the Center of Gravity(COG) variables when performing Air-rolling-breakfall motion, while passing forward over(PFO) to the vertical-hurdles(2m height, take off board 1m height) in judo. Subjects were four males of Y. University squad, who were trainees of the demonstration exhibition team, representatives of national level judoists and were filmed by four 5-VHS 16mm video cameras(60field/sec.) through the three dimensional film analysis methods.COG variable were anterior-posterior directional COG and linear velocity of COG, vertical directional COG and linear velocity of COG. The data collections of this study were digitized by KWON3D program computed The data were standardized using cubic spline interpolation based by calculating the mean values and the standard deviation calculated for each variables. When performing the Air-rolling-breakfall, from the data analysis and discussions, the conclusions were as follows : 1. Anterior-posterior directional COG(APD-COG) when performing Air-rolling-breakfall motion, while PFO over to the vertical-hurdles(2m height) in judo. The range of APD-COG by forward was $0.31{\sim}0.41m$ in take-off position(event 1), $1.20{\sim}1.33m$ in the air-top position(event 2), $2.12{\sim}2.30m$ in the touch-down position(event 3), gradually and $2.14{\sim}2.32m$ in safety breakfall position(event 4), respectively. 2 The linear velocity of APD-COG was $1.03{\sim}2.14m/sec$. in take-off position(event 1), $1.97{\sim}2.22m/sec$. gradually in the air-top position(event 2), $1.05{\sim}1.32m/sec$. in the touch-down position (event 3), gradual decrease and $0.91{\sim}1.23m/sec$. in the safety breakfall position(event 4), respectively. 3. The vertical directional COG(VD-COG) when performing Air-rolling-breakfall motion, while PFO to the vertical-hurdles(2m height) in judo. The range of VD-COG toward upward from mat was $1.35{\sim}1.46m$ in take-off position(event 1), the highest $2.07{\sim}2.23m$ in the air-top position(event 2), and after rapid decrease $0.3{\sim}0.58m$ in the touch-down position(event 3), gradual decrease $0.22{\sim}0.50m$ in safety breakfall position(event 4), respectively. 4. The linear velocity of VlJ.COG was $1.60{\sim}1.87m/sec$. in take-off position(event 1), $0.03{\sim}0.08m/sec$. gradually in the air-top position(event 2), $-4.37{\sim}\;-4.76m/sec$. gradual decrease in the touch-down position(event 3), gradual decrease and -4.40${\sim}\;-4.77m/sec$. in safety breakfall position(event 4), respectively. When performing Air-rolling-breakfall showed parabolic movement from take-off position to air-top position, and after showed vertical fall movement from air-top position to safety breakfall. In conclusion, Ukemi(breakfall) is safety fall method Therefore, actions need for performing safety fall movement, that decrease and minimize shock and impact during Air-rolling-breakfall from take-off board action to air-top position must be maximize of angular momentum, and after must be minimize in touch-down position and safety breakfall position.

Supporting plane for intelligent robot system (지능 로보트 시스템에 있어서 지면의 이용에 관한 연구)

  • 박경택
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10a
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    • pp.990-995
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    • 1991
  • The integration of intelligent robots into manufacturing systems should positively impact the product quality and productivity. A new theory of object location and recognition using the supporting plane is presented. The unknown supporting points are determined by image coordinates, known camera parameters, and joint coordinates of the robot manipulators. This is developed by using the geometrical interpretation of perspective projection and the geometrical constraints of industrial environments. This can be applied to solve typical robot vision problems such as determination of position, orientation, and recognition of objects.

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Development of Conveyor Belt Monitoring System (컨베이어 벨트상태 모니터링 시스템 개발)

  • 유재상
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.436-436
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    • 2000
  • In order to monitor the belt from being damaged by impact of large lump of materials in ores being transported on conveyor belt, we developed a conveyor belt monitoring system using vision. By the information such as the position and size of the damage of belt obtained by vision system, it is expected that not only the span of belt life will be lengthened, but also this system can enable operators to plan scheduled maintenance and prevent the enlargement of damaged parts in conveyor belt at an early stage

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