• Composites Research
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• v.24 no.3
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• pp.12-16
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• 2011

High strain rate tensile tests were performed to measure the strain rate sensitivity of fiber reinforced composite material. The composite material was developed for the light weight design of an automotive FEM(front end module) carrier. Standard specimens for quasi-static tests of fiber reinforced composites can be found in ASTM D3039. However, in case of high strain rate tests, it was hard to find standard specimen shapes. In this study, three kinds of tensile specimens designed based on ASTM D638 were investigated to determined the adequate gauge width of tensile specimen for fiber reinforced composite. A drop tower type of high speed tensile apparatus was developed for strain rates of about 15/s and 100/s. Gauge width of 6mm, 8mm and 10mm were investigated. Test results showed the specimen of 8mm width was adequate for the high strain rate tensile tests of fiber reinforced composite. It was found the strength of the composite material increased as the strain rate increased.

• Journal of the Korean Geosynthetics Society
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• v.22 no.1
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• pp.87-96
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• 2023

There are a lot of difference between the surface settlement and the differential settlement measured at the Busan New Port, where the dredged and reclaimed clay layer exists and below the clay is originally thickly distributed. To find the cause and solution of this, the actual conditions of each differential settlement used for the soft ground improvement, characteristics, installation method, measurement frequency, measurement data management, and data analysis of each type were considered. In the deep soft ground improvement work where large deformation occurs, the bending deformation of the screw-type differential settlement gauge is less than that of other types of measuring instruments, so there is less risk of loss, and the reliability of data is relatively high as the instruments are installed by drilling for each stratum. Since the greater the amount of high-precision settlement measurement data, the higher the settlement analysis precision. It is necessary to manage with higher criteria than the measurement frequency suggested in the standard specification. For the data management of the differential settlement gauge, it is desirable to create graphs of the settlement and embankment height of the relevant section over time, such as surface, differential, and settlement of pore water pressure gauge for each point. In the case of multi-layered ground with different compression characteristics, it is more appropriate to perform settlement analysis by calculating the consolidation characteristics of each stratum using a differential settlement data.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.26 no.3
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• pp.149-159
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• 2014

In this study, we develop an algorithm to predict swell-like high waves on the east coast of Korea using the directional wave gauge which was installed near Sokcho. Using the numerical wave model SWAN, we estimate wave data in open sea from the wave data collected by using the directional wave gauge. Then, using the wave ray method and SWAN model with the open-sea wave data as offshore boundary conditions, we predict the swell-like high waves at several major points on the east coast of Korea. We verify the prediction methods with the SWAN and wave ray methods by comparing predicted data against measured one at Wangdolcho. We can improve the prediction of the swell-like high waves in the east sea of Korea using both the real-time wave measurement system and the present prediction algorithm.

• The Transactions of the Korea Information Processing Society
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• v.4 no.9
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• pp.2378-2390
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• 1997

We, in this paper, have implemented E1 HDSL(high-bit-rate digital subscriber line) function over an ATM switching system. The maximum loop lengths for subscriber service and cell loss rates to meet the bit error rate of $10^{-7}$ at transmission of 2B1Q HDSL data of E1 rate over existing telephone copper wires in the presense of the significant impairments such as crosstalk, impulse noise, power line noise and longitudinal over the CSAs environment consisting of 26 gauge and 24 gauge unloaded copper telephone lines has assessed. We have confirmed the typical media services function such as video on demand(VOD) service for MPEG-1, image conference service and high-speed Internet access service over ATM switching system.

• Tunnel and Underground Space
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• v.17 no.6
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• pp.475-483
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• 2007

With increasing demand for LNG as energy resources and need for $CO_2$ sequestration as greenhouse gas, more storage facilities are required in Korea. Due to the recent acute safety concerns and land shortage, storage facilities tend to be located underground. In design and construction of underground storage for low and high temperature materials, besides their mechanical characteristics, the thermal characteristics of rock under temperature variation should be understood. In this study, laboratory experiments for the measurement of the thermal expansion coefficient of rock were performed using strain gauge in consideration of the particle size of mineral and experiment temperature range. Experiment results show that thermal expansion coefficient decreased as the temperature decreases. In addition, linear thermal expansion coefficient was developed for typical Korean rocks such as granite. The results of this study can be utilized for the evaluation of thermal propagation in rock mass and the thermo-mechanical stability of underground facilities.

• Journal of the Korea Fashion and Costume Design Association
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• v.14 no.2
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• pp.127-145
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• 2012

In an effort to investigate the overall trends of knit fabrics in fashion trends books, this study analyzed the components(fabric, yarn, gauge, thickness, knitting structure, pattern, dyeing and finishing) of knit fabrics in fashion trends books by the years and seasons from the S/S season of 2002 to the F/W season of 2011. Analyzed in the study were total 883 knit fabrics including the knit samples in Nelly Rodi Knitwear and Promostyl Fabrics. Collected data were put to frequency analysis with SPSS 12.0. Group mean analysis was also performed for thickness. The research results were as follows: As for knit fabrics in fashion trend books by the years and seasons, knit fabrics were most used in 2004 with similar frequency of knit fabrics among the seasons. As for fabric composition of knit fabrics, the uses of blend fabrics were considerably prominent both in S/S and F/W seasons and recorded the highest level in the S/S season of 2003 and the F/W season of 2002. As for gauge composition of knit fabrics, S/S seasons saw the most uses of fine G of 20G or higher, while F/W seasons saw the many uses of 12G-18G, which showed the highest frequency in 2002. As for knitting structure of knit fabrics, the plain stitch was used most both in S/S and F/W seasons and recorded the highest level in the S/S season of 2011 and the F/W season of 2007. As for pattern of knit fabrics, stripes and solid patterns were used most regardless of seasons. As for dyeing and finishing of knit fabrics, non-processed fabrics were used most, recording high frequency in the early 2000s.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.4 s.107
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• pp.380-386
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• 2006

Electric fuel sender fur the vehicle fuel gauge system was designed and fabricated based on the CPW(Co-Planer Waveguide) transmission line theory. It is applied on this system that characteristic impedance of RF transmission line can be varied by the surrounded material of the line. By the characteristic impedance owing the level of gasoline or diesel fuel in vehicle fuel tank, CPW line has corresponding reflected signal as much as changed impedance. Detected signal is amplified, and delivered to fuel indicator into cluster unit on dash board. Conventional floating mechanical buoy level gauge has several defects as low reliability and high break down rate by mechanical operation, and has not good linearity for the fuel level difference. CPW line with electric circuits are constructed on 1.6 mm thickness epoxy substrate, and measurement shows that this system has more accurate level and better linearity than conventional mechanical system. New electric fuel sender which has good productivity with long lifetime and low-in-cost by the SMT chip assembling could be replaced this system with conventional floating buoy system.

• Imaging Science in Dentistry
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• v.41 no.3
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• pp.115-121
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• 2011

Purpose : This article is to describe a modified device for intraoral radiography which was developed to obtain reproducible radiographic images for assessment of distal osseous defects of the mandibular second molar (2 Mm) after impacted third molar (3 Mm) surgery. Materials and Methods : A commercial available alignment system for posterior region was modified by adding a reference gauge pin (millimetric) and threading a hollow acrylic cylinder at the ring of the radiographic positioner to attach the X-ray collimator. The design included customized resin acrylic stent for the occlusal surface of the 2Mm in maximum intercuspal position, individualizing the biteblock positioner. Periapical radiographs were taken before and after surgical extraction of 3 Mm, employing the radiographic technique of parallelism described by Kugelberg (1986) with this modified film holder and inserting the gauge pin on the deepest bone probing depth point. Results : This technique permitted to obtain standardized periapical radiographs with a moderate to high resolution, repeatability, and accuracy. There was no difference between the measurements on the pre- and post-operative radiographs. This technique allowed better maintenance of the same geometric position compared with conventional one. The insertion of the gauge pin provided the same reference point and localized the deepest osseous defect on the two-dimensional radiographs. Conclusion : This technique allowed better reproducibility in posterior radiographic records (distal surface of 2 Mm) and more accurate measurements of radiographic bone level by the use of a millimetric pin.

• 유체기계공업학회:학술대회논문집
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• 2002.12a
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• pp.177-182
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• 2002

In the paper, the development of high-speed industrial turbo blowers with foil air bearings is presented as a first successful commercialization in the world. Their target market is various from wastewater treatment to cement factory processes which require compressed air ranging between 0.6 and 0.8 bar gauge. Employing the state-of·the-art technology of the high-speed BLDC motors, the bump-type foil air bearings and the high- efficient turbo impellers/diffusers, so much compact, efficient and silent blower machines of a single stage are now available in the market, aiming to replace the existing inefficient, bulky and noisy ones, such as roots blowers. The first production lines are established fur 25,75 and 150 hp class blowers. Rotational speeds from about 20,000 to 80,000 rpm are realized directly from the high-speed BLDC motors without any gear boxes, and no lubrication oil is required. A brief introduction of design, manufacture and test results is presented fur mechanical, electrical and aerodynamic performance.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.2
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• pp.39-52
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• 2020

A high quality, long-term, high-resolution precipitation dataset is an essential in climate analyses and global water cycles. Rainfall data from station observations are inadequate over many parts of the world, especially North Korea, due to non-existent observation networks, or limited reporting of gauge observations. As a result, satellite-based rainfall estimates have been used as an alternative as a supplement to station observations. The Climate Hazards Group Infrared Precipitation (CHIRP) and CHIRP combined with station observations (CHIRPS) are recently produced satellite-based rainfall products with relatively high spatial and temporal resolutions and global coverage. CHIRPS is a global precipitation product and is made available at daily to seasonal time scales with a spatial resolution of 0.05° and a 1981 to near real-time period of record. In this study, we analyze the applicability of CHIRPS data on the Korean Peninsula by supplementing the lack of precipitation data of North Korea. We compared the daily precipitation estimates from CHIRPS with 81 rain gauges across Korea using several statistical metrics in the long-term period of 1981-2017. To summarize the results, the CHIRPS product for the Korean Peninsula was shown an acceptable performance when it is used for hydrological applications based on monthly rainfall amounts. Overall, this study concludes that CHIRPS can be a valuable complement to gauge precipitation data for estimating precipitation and climate, hydrological application, for example, drought monitoring in this region.