• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.4
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• pp.75-82
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• 2014

A pin-type load-cell which uses shear-type strain gauges was developed to measure the tension of a wire in a winch. A finite element analysis was performed to determine the locations of the strain gauges. All of the shear-type strain gauges were attached onto parts that undergo regularly shear stress distributions. A Wheatstone bridge circuit was used to connect each of the gauges and to measure the strains. Linearity within the 5% error range was noted when testing the pin-type load-cell.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.4
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• pp.369-375
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• 2023

In this paper, we compared and analyzed the power load patterns of dormitory buildings and office buildings to use them as basic data (demand analysis and capacity design) for the design and operation of microgrids for multi-use facilities, and the following conclusions were got. During the daytime on regular weekdays, the power consumption load pattern of office buildings was relatively large at 264.0~332.3 kWh, and during the evening hours, the power consumption load pattern of dormitory buildings was relatively large at 233.0~258.3 kWh. In the case of vacation, during the daytime on weekdays, the power consumption load pattern of office buildings was relatively large at 279.1~407.4 kWh, and in the evening, the power consumption load pattern of dormitory buildings was relatively high at 280.1~394.1 kWh. During the daytime on regular weekends, the power consumption of dormitory-type buildings was relatively high at 133.5~201.6 kWh, and it was found that the power consumption of dormitory-type buildings appeared relatively high at 187.5~252.1 kWh. During a vacation in the daytime on weekends, the power consumption of dormitory-type buildings was found to be 186.5 kWh~ and 218.6 kWh. The increase in power consumption during a vacation (December-February) compared to normal (April-June) was thought to be due to an increase in electricity demand, and the reason for the higher power consumption in dormitory buildings during the vacation was due to reduced working hours in office buildings.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.3
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• pp.205-212
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• 2021

In this study, two types of thrust stand modeling were proposed for the design of a thrust stand using flexure. Type A model generate combined load for tangential (thrust) and axial compressive load (self weight). And type B generate combined load for tangential and axial tensile load. The research was done by comparing the influence of the load between the models through a 1D calculation and computational analysis. The 1D calculated value and the computational analysis value were compared for a total of 10 sections and the results were confirmed to be very similar. In order to prove the validity of the analysis results, the equivalent stress was confirmed from the computational analysis of the flexure, and the production of the Type B model was selected from the evaluation of the yield condition (Von-Mises Yield Criterion).

• Tribology and Lubricants
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• v.37 no.4
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• pp.136-143
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• 2021

This paper presents the loosening behavior that occurs after the application of an external load to internal and external connection types of dental implants using the finite element method. We use fastening force between an abutment and a fixture to clamp the dental implant system; however, loosening and breakage may occur owing to cyclic external loads. In this study, we considered the initial fastening condition in the pre-load analysis and then investigated the change in stress and contact surface status when applying external loads. After the application of the initial fastening load, we verified that the internal connection-type model exhibited a relatively lower stress distribution than that of the external connection-type one. Moreover, we found that the former model showed a lower stress concentration after the application of the external load. In addition, after the application of this load, we found that the higher the shear load acting on the implant system, the higher the possibility of loosening. The study results showed the change in stress distribution and contact surface according to the connection type of the dental implants and the phenomenon of loosening by cyclic loads. We expect that the results of this study will be useful for the study of reliability and design of dental implant systems.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.643-649
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• 2008

The purpose of this study is to establish a standard for unit cooling load in central control type apartment applied district cooling. The model of unit household was selected. And the standard of coefficient of overall heat transmission, location of unit household, indoor air temperature, solar radiation & thermal conduction at window and interior load was selected, and region, expansion or non-expansion of balcony, pyeong type, azimuth, rate of window area was applied as parameter. And then cooling load simulation was performed. Based on the result of simulation, the synthetic district cooling load was presented for selecting heat source of apartment applied district cooling, and unit cooling load was analyzed according to design parameter.

• The korean journal of orthodontics
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• v.21 no.3
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• pp.543-560
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• 1991

Practitioners are aware of the presence of friction between bracket system and archwire during sliding movement of teeth. Clinically a mesiodistally applied force must exceed the frictional force to produce a tooth movement. The objective of this study were to determine, on a dry condition, changes in magnitude of friction with respect to load, 3rd order inclination (Torque), archwire materials and ligature type. Three wire alloys (Stainless Steel, TMA, NiTi) in two wire sizes (.016, .016x, .022 inch) were examined respect to two bracket system (Straight, Standard), and two ligature type (Metal, Plastic ligature) at three levels of load (100g, 150g, 200g). The results were as follows; 1. Frictional resistance was found to increase with increasing load for S.S., TMA, NiTi. 2. The straight bracket system was exhibited more frictional force than standard bracket system for .016x, .022 S.S. tightly ligated metal ligature. But, torque difference did not increase friction for loose metal ligature & plastic ligature. 3. Regardless of the ligature type, torque and load, stainless steel wire sliding against stainless steel exhibited the lowest friction, and TMA sliding against stainless steel exhibited the highest friction. 4. The loose stainless steel ligature generated lower frictional resistance than plastic ligature in all experimental groups. 5. The following factors affected friction in decreasing order; wire material ligature type, and load.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.5
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• pp.685-691
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• 2013

A load-cell-type anemovane operates based on wind vector properties. The developed load-cell-type anemovane is of a fixed type in which the wing does not rotate, unlike in the case of existing anemovanes. The load-cell-type anemovane is required to accurately derive the correlation between the load ratio and the wind direction in order to develop a qualified product. This is because the load ratio repeats every $90^{\circ}$ owing to the use of four load cells, and its value varies nonlinearly according to the wind direction. In this study, we compared analytical results with experimental results. Fluid analysis was carried out using ANSYS CFX. Furthermore, the prototype was tested using a self-manufactured wind tunnel. The wind direction was selected as the design variable. 13 selected wind direction conditions ranging from $0^{\circ}$ to $90^{\circ}$ with an interval of $7.5^{\circ}$ for analysis were defined. Furthermore, 10 wind direction conditions with an interval of $10^{\circ}$ for the experiment were defined. We derived the relations between the pressure ratio and the wind direction through the experiment and fluid analysis.

• International Journal of Highway Engineering
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• v.8 no.3 s.29
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• pp.29-37
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• 2006

The primary objective of this study is to characterize traffic axle loadings that consider Korea specific traffic conditions for developing mechanistic-based pavement design method as a part of Korea Pavement Research Program(KPRP). Although the concept of equivalent single axle load(ESAL) has been generally used since the 1960s for the pavement design, the mechanistic-based pavement design procedure requires more accurate axle loading data on the specific pavement. In this study, axle loading data were collected according to vehicle type and highway functional classification. Axle-load spectrum was then standardized by cumulative density function(cdf), because the axle load spectrum could vary from the observed site, truck traffic volume, and truck type, Finally, this study presented the procedure and S-shaped exponential models for characterizing axle load spectra according to vehicle type and highway functional classification.

• Journal of the Korean Geotechnical Society
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• v.21 no.5
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• pp.51-58
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• 2005

In this study, the large scale model tests were executed to estimate the Load Sharing Ratio (LSR) of raft in a piled footing under various conditions. The conditions such as the subsoil type, pile length, pile spacing, away type and pile installation method etc. were varied in the pile loading tests about the free-standing group piles and a piled footing. As a result of this study, it was found that there was no difference in the load-settlement curves, resulting from the pile installation method and subsoil type. The piles supported most of the external load until a yielding load of the piled footing, but the raft supported a considerable load after a yielding load. As the relative density of sands increased, the LSR decreased. As the pile spacing was wider and the pile length increased, there was a tendancy for the LSR to increase. But it was also found that the LSR was not affected by the pile installation method and the subsoil type.

• Journal of Mechanical Science and Technology
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• v.16 no.6
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• pp.776-784
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• 2002

We have performed experimental studies for the improvements of pneumatic brake systems of freight trains. Currently, most of the freight trains operated by the Korean National Railroad have either empty-load or diaphragm type brake systems. In this study, appropriate methods that the air pressure characteristics in both type of brake systems are in accordance with each other have been investigated. We have also performed running tests using a 30 car-train set to design optimum capacity of a quick release valve. The test results show that the quick release valve is considerably effective in shortening the release time of the diaphragm type brake system. In the case of a normal brake application, the diaphragm type brake system with the quick release valve reduces the release time to 34% of that of the system without the quick release valve. This release time is almost equivalent to that of the empty-load type brake system. Accordance of braking performance in different types of brake systems in a train set is expected to prevent wheel flats and to reduce maintenance costs.