• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.2
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• pp.97-104
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• 2015

A fuzzy controller and a 2-dimensional wire-driven heavy material lifting system helping human operator are proposed in this paper. The 2-dimensional wire-driven heavy material lifting system is a kind of human-assistive systems in which a human is involved in the control loop. Most of the existing human-assistive control systems cannot consider human operator's characteristic. To consider human operator's characteristic, human's operating motion and requirement of reducing operator's force to lift a heavy material are considered in the design process of the proposed fuzzy controller. The performance of the proposed system is verified by experiments.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.4
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• pp.275-280
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• 2007

A turbine stage consists of stators and rotors. The stator provides the required inlet flow conditions so that the rotor can produce the necessary power. Passing wakes generated from the trailing edge of the stator make an interaction with the rotor. In the present study, this flow mechanism is investigated using the numerical analysis. In case of a large gap distance between the stator and rotor, the flow can be solved independently. First, only the stator flow field is solved. Second, the rotor flow field is solved including the passing wake characteristics obtained from the stator analysis. The passing wake experiences the shearing as it approaches to the rotor blade leading edge. And it is chopped when it strikes the rotor blade. After that, the chopped wakes becomes the prolongation as it travels downstream. The flow according to the variation of the gap distance is also studied. Pressure jumps due to the passing wakes result in the pressure and lift loss and it gets stronger with the closer gap distance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.307-313
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• 2010

Recently in Korea, or companies considering overseas expansion is often already begun. Past, enterprise's overseas economic cooperation fund(OECF) was consisted of overseas economic cooperation fund(OECF) of most large enterprise leading but medium and small enterprises as well as large enterprise is recognized for factor that competitive power security through overseas economic cooperation fund(OECF) is indispensable by economy opening Tuesday such as deregulation of great foreign enemy environment change and a technology and capital introduction. In the case of Korea, that advance of the China is going through bottleneck among by far bank Vietnam advance gradually expand. Therefore, in this study, I wished to quote plan for efficient and desirable Vietnam advance strategy establishment regarding our country enterprise's Vietnam advance through economy, politics, social environment analysis. In this study, can do on the basis of Vietnam advance connection domestic?outside literature investigation and virtue study through theoretical investigation according to these purpose and behaved theoretical investigation and lift construction materials allied industry, labor-intensive manufacturing industry, fisheries farm produce cultivation, processing household mascot etc. as energy industry, refined oil and petrochemical industry, electric-power industry, other field by our country medium and small enterprise.

• International Journal of Automotive Technology
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• v.6 no.3
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• pp.221-227
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• 2005

Aim of this study is to investigate an aerodynamic effect of a drag-reducing device on a heavy-duty truck. The vehicle experiences two different kinds of aerodynamic forces such as drag and uplifting force (or downward force) as it is traveling straight forward at constant speed. The drag force on a vehicle may cause an increase of the rate of fuel consumption and driving instability. The rolling resistance of the vehicle may be increased as result of the negative uplifting or downward force on the vehicle. A device named roof-fairing system has been applied to examine the reduction of aerodynamic drag force on a heavy-duty truck. As for a engineering design information, the drag-reducing system should be studied theoretically and experimentally for the best efficiency of the device. Four different types of roof-fairing model were considered in this study to investigate the aerodynamic effect on a model truck. The drag and downward force generated by vehicle has been obtained from numerical calculation conducted in this study. The forces produced on four fairing models considered in this study has been compared each other to evaluate the best fairing model in terms of aerodynamic performance. The result shows that the roof-fairing mounted truck has bigger negative uplifting or downward force than that of non-mounted truck in all speed ranges, and drag force on roof-fairing mounted truck has smaller than that of non-mounted truck. The drag coefficient $(C_D)$ of the roof-fairing mounted truck (Model-3) is reduced up to $41.3\%$ than that of non-mounted trucks (Model-1). A downward force generated by a roof-fairing mounted on a truck is linearly proportional to the rolling resistance force. Therefore, the negative lifting force on a heavy-duty truck is another important factor in aerodynamic design parameter and should be considered in the design of a drag-reducing device of a tractor-trailer. According to the numerical result obtained from present study, the drag force produced by the model-3 has the smallest of all in all speed ranges and has reasonable downward force. The smaller drag force on model-3 with 2/3h in height may results of smallest thickness of boundary layer generated on the topside of the container and the lowest intensity of turbulent kinetic energy occurs at the rear side of the container.

• Korean Journal of Materials Research
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• v.6 no.8
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• pp.817-824
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• 1996

Removal of Cu impurities on Si substrates using remote H-plasma was investigated. Si substrates were intentionally contaminated by 1ppm ${CuCI}_{2}$, standard chemical solution. To determine the optimal process condition, remote H-plasma cleaning was conducted varying the parameters of rf power, cleaning time and remoteness(the distance between the center of plasma and the surface of Si substrate). After remote H-plasma cleaning was conducted, Si surfaces were analysed by TXRF(total x-ray reflection fluorescence) and AFM(atomic force microscope). The concentration of Cu impurity was reduced by more than a factor of 10 and its RMS roughness was improved by more than 30% after remote H-plasma cleaning. TXRF analysis results show that remote H-plasma cleaning is effective in eliminating Cu impurity on Si surface when it is performed under the optimal process condition. AFM analysis results also verifies that remote H-plasma cleaning makes no damage to the Si surface. The deposition mechanism of Cu impurity may be explained by the redox potential(oxidation-reduction reaction potential) theory. Based on the XPS analysis results we could draw a conclusion that Cu impurities on the Si substrate are removed together with the oxide by a "lift-off" mechanism when the chemical oxide( which forms when Cu ions are adsorbed on the Si surface) is etched off by reactive hydrogen atoms.gen atoms.

• The Korean Journal of Physiology
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• v.2 no.2
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• pp.101-135
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• 1968

As physical fitness measured was muscle strength (hand grips, leg extention, back lift, and arm pull and thrust), skinfold thickness (5 different sites), circulatory function (resting heart rate and blood pressure), speed (kinesiological analysis during 100m sprint, record, maximal and final speed), motor function (50 meter dash, ball throwing, standing broad jump, and pull-ups), maximal aerobic power (maximum oxygen intake by field running method), muscle power (leg and arm by inertia ergometer), and general endurance (maximum endurance running time on the treadmill at the speed of 5 MPH and grade of 15.5%) of 1131 Korean children (boys 572, girls 559) aged of 6 to 17 years, who were randomly sampled from 24 primary, middle and high schools at the two districts of Seoul and KyungKi. The results are summarized as follows: 1) The status (height and weight) of the children was almost same as that of the previously reported Korean and Japanese children of same ages. 2) Muscle strength was a gained linearly with geting age in the boys and girls but there was a little improvement in girls aged of 13 years or more. 3) The mean skin fold thickness was increased linearly with geting ages in both sexes, but the girls from 12 to 17 years of age were increased rapidly, and maximum value was 17mm, while boys was 7.0 mm. 4) In the circulatory function, the resting heart rate was decreased, but the blood pressure was increased with ages in both sexes within the normal limits. 5) The maximum and final speed during 100 meter sprint increases with age in boys but girls who are 12 years old or older, were not improved any mere. The patterns of running were same in both sexes, and maximum speed reached at about 30 meters from starting line. 6) The motor function was increased with age in both sexes, but there was no improvement in 12 years of age or older girls. More over records of all functions except standing broad jump was less than those of Japanese in the same age, respectively. 7) The maximum oxygen intake (MOI) was increased considerably with ages and maximum values were 2.93 L/min (boys) and 2.09 L/min (girls) at the age of 17years. This result was almost same as that of the Japanese and Easter Island population, but the value was lower than that of Europe. The average of the maximum oxygen intake per kg body weight per minute from 9 to 17 years of age were around 53 ml in the boys and 42 ml in the girls. 8) Muscle power was increased linearly with ages in boys while there was relatively a little increment in girls. The maximum values of leg muscle in boys and girls at the 17 years of age were 0.168 and 0.088 horse power, respectively. 9) The maximum endurance running time was increased considerably from the age of 9 in boys, while there was no improvement in girls. The maximum values were 6.0 min and 1.8 min, respectively.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.10
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• pp.1109-1116
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• 2014

The wheelchair mechanism for a car that is proposed in this study primarily consists of a transfer mechanism and storage mechanism. The wheelchair transfer mechanism consists of a manipulator installed in the roof of a car, and performs the function of transferring the wheelchair from the driver's seat to the trunk. The wheelchair storage mechanism consists of a lifting hoist installed in the trunk of car, and performs the function of storing the transferred wheelchair in the trunk and safely fastening it in place. This study analyzed and reviewed various manipulators, including a vertical type, Scara type, and telescopic type, with the goal of selecting the best type of manipulator for the wheelchair transfer mechanism. The telescopic type was selected and applied because of its good load support and storage capabilities. In addition, with regard to the wheelchair storage mechanism, a slide hoist type that used a slide rail and lift wire and a rotating link hoist type that used a rotating mechanism consisting of a worm gear and link were analyzed and reviewed. The slide hoist type was selected and applied because it had an advantage in relation to trunk space utilization. This study proposed a wheelchair transfer mechanism for a car to support a conventional wheelchair user's movements, and in order to conform to the structure of a domestic welfare car for the disabled.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.12 s.159
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• pp.1800-1809
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• 2006

The wearable technology takes the concept of clothing over its limits -integrating software, communication devices, and sensors into the garments to enable them to 'think' for the wearer. A dress is no longer just a dress, but a dress as well as a wearable computer interface. This wearable computer network transports the data power and control signals within the wearer's personal space. The purpose of this thesis is to explore the wearable technology from a commercial perspective. On this theme I made a survey and interviewed 20 men and 20 women in London to find out if many people are familiar with the concept of the wearable technology. The main results of this study include: Firstly, according to the survey, people are not familiar with the concept of the wearable technology, and further people thought negatively about the wearable computer rather than positively they worried about hish prices, inappropriate technology and side effects. Secondly, people are especially interested in items related to health and security, so in this area there are huge potential opportunities for the wearable technology, Finally, wearable technology needs to be a simplified set of interactive devices, which are in a user friendly format for marketability because convenience was one of the biggest concern for consumers. Therefore, development of the wearable computer should be promoted not only through computer engineering but also through the connection with human lift.

• Journal of the Korea Society of Computer and Information
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• v.10 no.2 s.34
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• pp.205-213
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• 2005

A balanced regional development has a great meaning of economics in the fact that the People could enjoy the equal level of lift everywhere in the country by reducing the income disparity and economic productivity between regions, however as the our country was given Preponderance of economical power and development to the metropolitan area centering around Seoul due to a factor of politics, social structure as well as a national economic policy centering around a rapid economic growth, the unbalanced regional growth gave rise to great hindrance to a national development. Especially, the unbalanced 9rowth between regions gave rise to a sense of alienation to a citizen in a special region as well as a distortion of an effective resources distribution. therefore it was deepen a social discord to hinder the unity of the people due to always coming to involve social ,political affairs. The major contents of this study is to clarify relations between the economic growth and the balanced regional development to form a concept of a national development, and this thesis made disparities in population and convenient facilities between regions through change of convenient facilities of life, economic growth, and population between regions an analytic object to concrete the studies. Also, this thesis made a whole countw land an analytic object of spatial sphere. and it made a unit of ten years when the five-year economic development plan was achieved from the year 1962 to 2001 an otject of the time range of studies.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.4
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• pp.164-167
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• 2010

Bulk GaN single crystal with 1.5 mm thickness was successfully grown by hydride vapor phase epitaxy (HVPE) technique. Free-standing GaN substrates of $10{\times}10,\;15{\times}15$ mm size were fabricate after lift-off of sapphire substrate and their optical properties were characterized properties for device applications. X-ray diffraction patterns showed (002) and (004) peak, and the FWHM of the X-ray rocking curve (XRC) measurement in (002) was 98 arcsec. A sharp photoluminescence spectrum at 363 nm was observed and defect spectrum at visible range was not detected. The hexagonal-shaped etch-pits are formed on the GaN surface in $200^{\circ}C\;H_3PO_4$ at 5 minutes. The defect density calculated from observed etch-pits on surface was around $5{\times}10^6/cm^2$. This indicates that the fabricated GaN substrates can be used for applications in the field of optodevice, and high power electronics.