• 한국안전학회지
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• 제30권4호
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• pp.92-98
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• 2015

This paper was carried out to prove the relation between static loads acting on the sluice(hydrostatic) and dynamic loads (additional loads) arising from opening or closing of sluice, through measuring the operation of shell-type roller gate by using the method of measuring of the completely opening water gate, as measured from one excitation state, it was confirmed to be capable of measuring the natural frequency reliable measurement results. Throughout the test, we prove that it's a reasonable way to estimate the default margin of safety when calculated by dividing the sum of the hydrostatic stress to the maximum stress and additional stress. The application of this paper's safety estimation method can be utilized as the basic data for the systematic and rational maintenance management of dams and submerged weirs in the future, and it is expected that this study can bring forth.

• 한국전기전자재료학회논문지
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• 제30권10호
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• pp.677-682
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• 2017

Lamination is used extensively in various industries. The type of lamination applied to the material depends on the precision level required, which varies for materials needed for everyday use, materials used in high-tech industries, and processes employed to fabricate finished products. Especially in hot lamination, the distribution of the surface temperature of the heating roller is very important to avoid the generation of internal bubbles and ensure flatness of the attached materials, and thus maintain a good standard of quality and productivity. In this study, we have developed a system to monitor the surface temperature of the heating rollerby applying a heterogeneous controller and a non - contact temperature sensor. This monitoring system accurately measures the surface temperature of the heating roller and applies the RS485 MODBUS communication method for easy expansion. Using this system, a laminated prototype was fabricated, and its efficacy for non-contact temperature sensor calibration, Ethernet IP communication, stoppage of the heating roller, and determination of temperature distribution with rotation was examined for its potential usage in industries.

• Child Health Nursing Research
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• 제12권1호
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• pp.75-83
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• 2006

Purpose: This study was done to verify the effect of roller acupuncture stimulation on baesu spots of joktaeyang bangkwang kyeong in the reaction to physiologic pain(heart rate, percutaneous oxygen saturation, respiration rate) in neonates. Method: This study was a nonequivalent control group non-synchronized design. The participants were 40 normal neonates who were born at a hospital in Busan. These neonates were undergoing heel puncture for blood type tests. The neonates were divided into 2 groups: 20 in the experimental group who were stimulated with roller acupuncture before the heel puncture and 20 neonates in the control group who were not stimulated. The heart rate and percutaneous oxygen saturation were measured using a cardiopulmonary monitor and the respiration rate was measured directly. The data were analyzed with SPSS 10.0 program using χ²-test, t-test and Repeated Measure ANOVA. Results: There was a significant difference (F=3.287, p=.043) for heart rate on the interaction between time and group. There was a significant difference (F=5.122, p=.008) for percutaneous oxygen saturation on the interaction between time and group. Conclusion: On the basis of results, it was verified that the roller acupuncture stimulation on baesu spots of joktaeyang bangkwang kyeong had effect of relieving pain in the neonates.

• 반도체디스플레이기술학회지
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• 제9권2호
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• pp.91-96
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• 2010

In recent years there have been considerable attentions on nanoimprint lithography (NIL) by the display device and semiconductor industry due to its potential abilities that enable cost-effective and high-throughput nanofabrication. Although one of the current major research trends of NIL is large-area patterning, the technical difficulties to keep the uniformity of the residual layer become severer as the imprinting area increases more and more. In this paper we consider the roll-to-plate type imprinting process. In the process a glass mold, which is placed upon the 2nd generation TFT-LCD glass sized substrate(370${\yen}$470 mm), is rolled by a rubber roller to achieve a uniform residual layer. The pressure distribution on the glass mold by rolling of the rubber roller is crucial information to analyze mold deformation, transferred pattern quality, uniformity of residual layer and so forth. In this paper the quantitative pressure distribution induced by rolling of the rubber roller was calculated with finite element analysis under the assumption of Neo-Hookean hyperelastic constitutive relation. Additionally the numerical results were verified by the experiments.

• 한국기계가공학회지
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• 제19권7호
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• pp.52-59
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• 2020

Automatic tool changers (ATCs) can be divided into drum and chain types. Drum-type ATCs contain a magazine, where the tools are mounted, and a cam gearbox, which swaps the tools via roller gear and grooved plate cams. Drum-type ATCs are advantageous in that the operating time for the tool magazine is more rapid than that of chain-type ATCs and the length of the unit is shorter. Thus, drum-type ATCs can be fabricated into various shapes and forms depending on the number of tools and the magazine size in accordance with machining center requirements and consumer demand. In particular, the price competitiveness of a machining center with a drum-type ATC is higher, while drum-type ATCs are more rigid with fewer parts, possibly reducing the need for regular servicing. This study aims to verify the structural stability and design validity of the magazine base, which is the main structure of a drum-type ATC, using finite element analysis. This study kinematically verifies the specifications of the selected drive motor and reducer and assessed the design of the cam gearbox. It also conducts a structural analysis of the roller camp, which is the core component of the cam gearbox, based on the results of the kinetodynamic analysis, thus validating the structural design.

• 반도체디스플레이기술학회지
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• 제9권1호
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• pp.23-28
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• 2010

In this paper, wafer drop from wafer guide mechanism, which is one of the serious problems in water transfer robot, is analyzed, and new wafer guide mechanisms are proposed to minimize this drop. Three types of new wafer guide mechanisms are proposed: roller type, gear type and L-shape rocker type. We choose one of the proposed mechanism, which is roller type, and verified this mechanism through real transfer experiment. Wafer picking up test is conducted with initial aligning error for simulating the wafer drop. Number of drop is compared between conventional mechanism and proposed mechanism. As a result, we can find the proposed mechanism can reduce the number of wafer drop dramatically.

• 한국정밀공학회지
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• 제14권3호
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• pp.35-40
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• 1997

The traction drive has advantages of having high efficiency and transmitting the power without blacklash. However, when high ratio of speed reduction is desired, excessively large size is required. In this study, a new type of traction drive is invented, designed and manufactured so that stable speed reduction mech- anisms are available by adopting a cross roller type drive. It has a simple structure, but produces high speed reduction ratio. Power loss is observed, and also, driving torque and torque transfer efficiency are calculated. Pre-loads are needed in order that the traction drive transfers power without slipping, and the spacer is enlarged due to the pre-loading. After all, the key point of pre-load mechanism is that the spacer's diameter becomes larger as pre-loads are applied.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1446-1449
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• 2003

In this study we analyze operation principle of wedge type rail clamp using in the harbor and when wind force applies to container crane, we calculate deformation in each part of rail clamp. As a result of calculation, we will design rail clamp supporter that forbid overload to be applied at rail clamp according to adjust climbing wedge distance of roller. It would be adapted various container capacity and wind velocity.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1991년도 제13회 학술강연회초록집
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• pp.50-54
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• 1991

This paper shows the effect of axial profile on the elastohydrodnamic lubrication (EHL) behavior of axially profiled cylindrical roller. For two different type of profiles which have nearly similar elastostatic pressure distribution, the EHL results show large differences. Especially the difference in film shape is larger than that of pressure distribution. Therefore, the magnitude of the minimum film thickness should be a major criteria to design the axial profile of the roller and a new design procedure is presented which take into account the minimum film thickness as well as the pressure distribution.

• Journal of Biosystems Engineering
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• 제43권4호
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• pp.303-310
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• 2018

Purpose: This research was conducted to determine the design factors of a seed-metering device for the development of a seeder. The device allows the seeder to sow precisely one to three seeds of foxtail millet and sorghum. To obtain fundamental information regarding the design of the seed-metering device, examination of the physical properties of foxtail millet and sorghum was conducted. Methods: Based on the results of an adaptability test using an existing seeder with foxtail millet and sorghum, an experimental roller-type seed-metering device was made. The seeding factors considered during the experiment were the width, length, and depth, as well as the shape of the groove in the seed-metering roller. By adapting an analysis of variance, the experimental results of the seeding factors were analyzed. Results: The measured results of the respective lengths and widths of the seeds were 2.11 and 1.64 mm for foxtail millet, and 3.68 and 3.32 mm for sorghum, respectively. The weight of 1,000 seeds was 2.43 g for foxtail millet and 17.5 g for sorghum. The seeds were of an elliptical shape, considering the length and width. A sieve analysis showed that the size distribution of foxtail millet was quite regular whereas that of sorghum was irregular. Conclusions: The seeding results showed that the rates of incorrect planting were low when the groove of the roller-type metering device is an elliptical type. To sow one to three seeds, the groove of roller-type metering devices $2.0mm{\times}4.0mm{\times}1.5mm$ ($width{\times}length{\times}depth$) for foxtail millet, and $4.0mm{\times}8.0mm{\times}3.0mm$ and $4.5mm{\times}8.0mm{\times}3.0mm$ ($width{\times}length{\times}depth$) for Sorghum.