• Title/Summary/Keyword: a force generation

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The Effect of High-Heeled Shoes With Total Contact Inserts in the Gait Characteristics of Young Female Adults During Lower Extremity Muscle Fatigue (하지 근육의 피로상태 동안 높은 굽 신발에 적용한 전면접촉인솔이 젊은 여성의 보행 특성에 미치는 영향)

  • Ko, Eun-Hye;Choi, Houng-Sik;Kim, Tack-Hoon;Cynn, Heon-Seock;Kwon, Oh-Yun;Choi, Kyu-Han
    • Physical Therapy Korea
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    • v.15 no.1
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    • pp.38-45
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    • 2008
  • This study investigated gait characteristics, kinematics, and kinetics in the lower extremities between two different shoe conditions (high heeled shoes (7 cm), and high heeled shoes with a total contact insert (TCI)) after lower extremity muscle fatigue. Although TCI shave been applied in high heeled shoes to increase comfort and to decrease foot pressure, no study has attempted to identify the effects of TCI in fatigue conditions. The purpose of this study was to determine the effects of walking in high heeled shoes with TCI after lower extremity muscle fatigue was induced. This study was carried out in a motion analysis laboratory at Hanseo University. A volunteer sample of 14 healthy female subjects participated. All in fatigue conditions, the subjects were divided into two groups. The muscle fatigue was induced by 40 voluntary dorsi- and plantar-flexion exercises and 40 heel-rise exercises of the dominant foot. Surface electromyography was used to confirm the localized muscle fatigue using power spectral analysis of three muscles (tibialis anterior, gastrocnemius medialis and lateralis). The results were as follows: (1) In muscle fatigue conditions, the use of TCI decreased the peak flexion angle of the hip joint significantly in the early stance phase (p<.05) and increased the peak hip flexion moment in the terminal stance phase (p<.05). (2) In muscle fatigue conditions, the application of TCI also increased peak hip power generation in the early stance phase and peak hip power absorption in the terminal stance phase (p<.05). (3) In muscle fatigue conditions, the use of TCI reduced the impact force significantly and increased the secondary peak vertical GRF. These findings suggest that the TCI may provide beneficial effects when muscle fatigue occurs for a high heeled shoe gait. Future research employing the patient population and various types of TCI materials are required to clarify the effects of TCI.

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Experimental Study for the Resonance Effect of the Power Buoy Amplitude (공진형 전력부이의 상하변위증폭 효과에 관한 실험적 연구)

  • Kweon, Hyuck-Min;Koh, Hyeok-Jun;Kim, Jung-Rok;Choi, Young-Hwan
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.2
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    • pp.585-594
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    • 2013
  • In this study, laboratory experiments and numerical simulations were conducted to test the performance of resonance power buoy system proposed by Kweon et al.(2010). The system is composed of a linear generator and a mooring buoy. The mover of the linear generator mainly has heave motion driven by vertical oscillation of the buoy. In this system, the velocity discrepancy between the mover and the buoy makes electricity. However, ocean wave energy as a natural resource around Korean peninsula is comparatively small and the driving force for producing electricity is not enough for commercialization. Therefore, it is necessary that the buoy motion be amplified by using resonance characteristics. In order to verify the resonance effects on the test power buoy, the experimental investigations were conducted in the large wave flume (length of 110 m, width of 8 m, maximum depth of 6 m) equipped with regular and random plunger wave generator. The resonance draft of test power buoy is designed for the corresponding period of incident wave, 1.96 sec. Regular wave test results show that the heave response amplitude operator(RAO) by a test buoy has the amplification of 5.66 times higher compared to the wave amplitude at the resonance period. Test results of random waves show that the buoy has the largest spectrum area of 20.73 times higher at the point of not the resonance period but the shorter one of 1.85 sec. Therefore this study suggests the resonance power buoy for wave power generation for commercial application in the case of the coastal and oceanic area with smaller wave energy.

Research on Development of Turbo-generator with Partial Admission Nozzle for Supercritical CO2 Power Generation (부분 유입 노즐을 적용한 초임계 이산화탄소 발전용 초고속 터보발전기 개발 연구)

  • Cho, Junhyun;Shin, Hyung-ki;Kang, Young-Seok;Kim, Byunghui;Lee, Gilbong;Baik, Young-Jin
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.41 no.4
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    • pp.293-301
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    • 2017
  • A Sub-kWe small-scale experimental test loop was manufactured to investigate characteristics of the supercritical carbon dioxide power cycle. A high-speed turbo-generator was also designed and manufactured. The designed rotational speed of this turbo-generator was 200,000 rpm. Because of the low expansion ratio through the turbine and low mass flowrate, the rotational speed of the turbo-generator was high. Therefore, it was difficult to select the rotating parts and design the turbine wheel, axial force balance and rotor dynamics in the lab-scale experimental test loop. Using only one channel of the nozzle, the partial admission method was adapted to reduce the rotational speed of the rotor. This was the world's first approach to the supercritical carbon dioxide turbo-generator. A cold-run test using nitrogen gas under an atmospheric condition was conducted to observe the effect of the partial admission nozzle on the rotor dynamics. The vibration level of the rotor was obtained using a gap sensor, and the results showed that the effect of the partial admission nozzle on the rotor dynamics was allowable.

A Study on Image-Based Mobile Robot Driving on Ship Deck (선박 갑판에서 이미지 기반 이동로봇 주행에 관한 연구)

  • Seon-Deok Kim;Kyung-Min Park;Seung-Yeol Wang
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.7
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    • pp.1216-1221
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    • 2022
  • Ships tend to be larger to increase the efficiency of cargo transportation. Larger ships lead to increased travel time for ship workers, increased work intensity, and reduced work efficiency. Problems such as increased work intensity are reducing the influx of young people into labor, along with the phenomenon of avoidance of high intensity labor by the younger generation. In addition, the rapid aging of the population and decrease in the young labor force aggravate the labor shortage problem in the maritime industry. To overcome this, the maritime industry has recently introduced technologies such as an intelligent production design platform and a smart production operation management system, and a smart autonomous logistics system in one of these technologies. The smart autonomous logistics system is a technology that delivers various goods using intelligent mobile robots, and enables the robot to drive itself by using sensors such as lidar and camera. Therefore, in this paper, it was checked whether the mobile robot could autonomously drive to the stop sign by detecting the passage way of the ship deck. The autonomous driving was performed by detecting the passage way of the ship deck through the camera mounted on the mobile robot based on the data learned through Nvidia's End-to-end learning. The mobile robot was stopped by checking the stop sign using SSD MobileNetV2. The experiment was repeated five times in which the mobile robot autonomously drives to the stop sign without deviation from the ship deck passage way at a distance of about 70m. As a result of the experiment, it was confirmed that the mobile robot was driven without deviation from passage way. If the smart autonomous logistics system to which this result is applied is used in the marine industry, it is thought that the stability, reduction of labor force, and work efficiency will be improved when workers work.

Concepts of Disaster Prevention Design for Safety in the Future Society

  • Noh, Hwang-Woo;Kitagawa, Keiko;Oh, Yong-Sun
    • International Journal of Contents
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    • v.10 no.1
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    • pp.54-61
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    • 2014
  • In this paper, we propose a pioneering concept of DPD(Disaster Prevention Design) to realize a securable society in the future. Features of danger in the future society are expected to be diverse, abrupt occurring, large scale, and complicated ways. Due to increment of dangers with their features of uncertainty, interactivity, complexity, and accumulation, human-oriented design concept naturally participates in activities to prevent our society against disasters effectively. We presented DPD is an essential design activity in order to cope with dangers expected in the future societies as well as realize securable environments. DPD is also an integrated design aids including preemptive protections, rapid preparing, recovery, and interactive cooperation. We also expect these activities of DPD is effective for generation of new values in the market, satisfaction of social needs, expansion of design industry, and a novel chance for development in the future society. Throughout this paper, we submit various aspects of DPD concepts including definition, classification, scope, necessity, strategy, influencing elements, process, and its principle. We expect these concepts will be the seed and/or basement of DPD research for the future works. For the direction of study for DPD in the future, we emphasize alarm system for preemptive protection rather than recovery strategy for the damage occurred. We also need to research about progressive prevention techniques and convergence with other areas of design. In order to transfer the concept of product design from facility-oriented mechanism to human-oriented one, we should develop new kinds of city basis facilities, public-sense design concepts referred to social weak-party, e-Learning content design preparing disasters, and virtual simulation design etc. On the other hand, we have to establish laws and regulations to force central and/or provincial governments to have these DPD strategies applying their regional properties. Modern design activities are expanding to UI(user interface) content design area overcoming the conventional design concept of product and/or service. In addition, designers are recognized as art directors or life stylists who will change the human life and create the social value. DPD can be divided into prevention design, preparedness design, response design, and recovery design. Five strategies for successful DPD are Precaution-oriented, Human-oriented, Sense-oriented, Legislation, and Environment Friendly Strategies.

Process Optimization of PECVD SiO2 Thin Film Using SiH4/O2 Gas Mixture

  • Ha, Tae-Min;Son, Seung-Nam;Lee, Jun-Yong;Hong, Sang-Jeen
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.434-435
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    • 2012
  • Plasma enhanced chemical vapor deposition (PECVD) silicon dioxide thin films have many applications in semiconductor manufacturing such as inter-level dielectric and gate dielectric metal oxide semiconductor field effect transistors (MOSFETs). Fundamental chemical reaction for the formation of SiO2 includes SiH4 and O2, but mixture of SiH4 and N2O is preferable because of lower hydrogen concentration in the deposited film [1]. It is also known that binding energy of N-N is higher than that of N-O, so the particle generation by molecular reaction can be reduced by reducing reactive nitrogen during the deposition process. However, nitrous oxide (N2O) gives rise to nitric oxide (NO) on reaction with oxygen atoms, which in turn reacts with ozone. NO became a greenhouse gas which is naturally occurred regulating of stratospheric ozone. In fact, it takes global warming effect about 300 times higher than carbon dioxide (CO2). Industries regard that N2O is inevitable for their device fabrication; however, it is worthwhile to develop a marginable nitrous oxide free process for university lab classes considering educational and environmental purpose. In this paper, we developed environmental friendly and material cost efficient SiO2 deposition process by substituting N2O with O2 targeting university hands-on laboratory course. Experiment was performed by two level statistical design of experiment (DOE) with three process parameters including RF power, susceptor temperature, and oxygen gas flow. Responses of interests to optimize the process were deposition rate, film uniformity, surface roughness, and electrical dielectric property. We observed some power like particle formation on wafer in some experiment, and we postulate that the thermal and electrical energy to dissociate gas molecule was relatively lower than other runs. However, we were able to find a marginable process region with less than 3% uniformity requirement in our process optimization goal. Surface roughness measured by atomic force microscopy (AFM) presented some evidence of the agglomeration of silane related particles, and the result was still satisfactory for the purpose of this research. This newly developed SiO2 deposition process is currently under verification with repeated experimental run on 4 inches wafer, and it will be adopted to Semiconductor Material and Process course offered in the Department of Electronic Engineering at Myongji University from spring semester in 2012.

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Identification of Quantitative Trait Loci(QTL) for Meat Color Trait on Chromosome 7 in Pig (돼지 7번 염색체에서 육색 연관 QTL 확인)

  • Choi, B.H.;Lee, H.Y.;Kim, T.H.;Hong, K.C.;Cheong, I.C.
    • Journal of Animal Science and Technology
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    • v.46 no.4
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    • pp.525-536
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    • 2004
  • The objective of this study was to identify the quantitative traits loci(QTL) for meat quality traits in pigs. Three-generation resource population was constructed from a cross between Korean native boars and Landrace sows. The resource population including founders, $F_1$ and $F_2$ was genotyped for 23 microsatellite markers on chromosome 7. The sex average total length of linkage map on chromosome 7 was estimated 154.6 cM. Meat quality traits including meat pH, meat color, drip loss, shear force, heating loss, crude fat, crude protein, crude ash and water content in muscle were collected from $F_2$ animals. For the QTL mapping, we used $F_2$ QTL Analysis Servlet of QTL express for web-based QTL mapping tools(http://qtl.cap.ed.ac.uk/). The QTLs for CIE-a and CIE-b on SSC7 were significantly detected at 1% and 5% chromosome-wide level, respectively.

Workfare in the United Kingdom : A Study on New Deal under the New Labour Government (영국의 근로연계복지에 관한 평가 : 신노동당 정부의 New Deal을 중심으로)

  • Shin, Dong-Myeon
    • Korean Journal of Social Welfare
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    • v.56 no.1
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    • pp.23-43
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    • 2004
  • The purpose of this paper is to evaluate the performance of New Deal under the New Labour government in Britain and examines the nature of New Deal with respect to workfare. The time difference of five years after the New Deal was put into effect shows that New Deal has contributed not only to include the socially excluded groups such as the young unemployed, the long-term unemployed, single parents, and the disabled into the labour market, but also to decrease the amount of income-based benefits providing for working generation. It can be said that the nature of New Deal under the New Labour is near to human capital development model rather than labour force attachment model. New Deal provides the opportunity of policy learning for the countries which pursue the reform of social security system to moving welfare beneficiaries being able to work into jobs. Policy learning can be summed up as follows. First, imposing mutual responsibility and obligations on unemployed person should be accompanied by implementing active labour market programmes of education and job training. Second, the delivery system which administrates workfare programmes should be decentralized in a local society. The cooperation between local government and enterprisers will be critical in implementing various employment programmes and moving unemployed person into jobs. Third, the case management for individual participating in workfare programme is necessary. The personal adviser should continue to provide employment services for the unemployed until he or she get a job and enter the state of self-reliance. Finally, the workfare programme should be firmly backed by the political leadership in order to overcome the oppositions of beneficiary groups under the existing social security system.

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Fabrication and Characterization of Lead Oxide (PbO) Film for High Efficiency X-ray Detector (고효율 X선 검출기 적용을 위한 PbO 필름 제작 및 특성 연구)

  • Cho, Sung-Ho;Kang, Sang-Sik;Choi, Chi-Won;Kwun, Chul;Nam, Sang-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.329-329
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    • 2007
  • Photoconductive poly crystalline lead oxide coated on amorphous thin film transistor (TFT) arrays is the best candidate for direct digital x-ray detector for medical imaging. Thicker films with lessening density often show lower x-ray induced charge generation and collection becomes less efficient. In this work, we present a new methodology used for the high density deposition of PbO. We investigate the structural properties of the films using X-ray diffraction and electron microscopy experiments. The film coatings of approximately $200\;{\mu}m$ thickness were deposited on $2"{\times}2"$ conductive-coated glass substrates for measurements of dark current and x-ray sensitivity. The lead oxide (PbO) films of $200\;{\mu}m$ thickness were deposited on glass substrates using a wet coating process in room temperature. The influence of post-deposition annealing on the characteristics of the lead oxide films was investigated in detail. X-ray diffraction and scanning electron microscopy, and atomic force microscopy have been employed to obtain information on the morphology and crystallization of the films. Also we measured dark current, x-ray sensitivity and linearity for investigation of the electrical characteristics of films. It was found that the annealing conditions strongly affect the electrical properties of the films. The x-ray induced output charges of films annealed in oxygen gas increases dramatically with increasing annealing temperatures up to $500^{\circ}C$ but then drops for higher temperature anneals. Consequently, the more we increase the annealing temperatures, the better density and film quality of the lead oxide. Analysis of this data suggests that incorporation and decomposition reactions of oxygen can be controlled to change the detection properties of the lead oxide film significantly. Post-deposition thermal annealing is also used for densely film. The PbO films that are grown by new methodology exhibit good morphology of high density structure and provide less than $10\;pA/mm^2$ dark currents as they show saturation in gain (at approximate fields of $4\;V/{\mu}m$). The ability to operate at low voltage gives adequate dark currents for most applications and allows voltage electronics designs.

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Customer Intangible Value in a Social Network (사회적 네트워크에서의 고객무형가치에 대한 연구)

  • Han, Sangman;Lee, Jieun
    • Asia Marketing Journal
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    • v.10 no.4
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    • pp.99-121
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    • 2009
  • Social networks can be a powerful force in marketing because they provide new ways to market to young generation. Though many studies on evaluation of customer lifetime value have been conducted, it is not clear how to assess the value of members within social networks. The purpose of this study is to evaluate members based on customer intangible value as well as customer lifetime value. Customer network value in terms of the power and influence within a network is analyzed through network structure analysis. Using Cyworld log file data, this study have shown that high percentage of members are very influential in terms of spreading or withholding information even though their CLV is low. It is expected that the findings of this research contribute to understand the interactive behaviors of members within networks and to provide valuable implications on new product launching and customer management strategies to marketers.

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