• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.665-668
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• 2003

In this paper, we have designed and implemented the RAID controller board which connects to the host computer with serial ATA interface and connects to the disks with parallel ATA interface. Serial ATA interface is proposed to overcome the design limitation of parallel ATA while enabling the storage interface to scale with the slowing media rate demands for PC platforms. Serial ATA is to replace parallel ATA with the compatibility with existing operating systems and drivers, adding performance headroom for years to come. It Moreover, serial ATA provides even faster transfer rate of 150 Mbytes/s which is larger than that of current parallel ATA. The RAID controller board designed in this paper combines up to 4 disks with parallel ATA interface, and connects to PC host computer with serial ATA interface. We have implemented RAID controller using Verilog HDL language with FPGA chip. The RAID controller supports RAID level 0 and 1 functionality. Experimently, the average read/write performance of parallel ATA interface is about 30 Mbytes/s. Therefore, when 4 parallel disks is connected to the RAID controller board, we can get almost full throughput of serial ATA protocol using the RAID level 0 configuration with 4 disks.

• Journal of Korean Society of Rural Planning
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• v.23 no.4
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• pp.61-74
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• 2017

In recent years, various policies have been conducted for the activation of the value chain for 6th industrialization of agriculture, which is aligned with creating job opportunities and start-up as well as value added enhancement. For this reason, this study seeks measures to kick-start application and development of a model to raise the success rate of startups and reduce the risk of market throughout surveying 168 6th industrialization management bodies about their start-up and business, and benchmarking of best practices, a case consistent with the value chain system of 6th industrialization of agriculture. Main findings are three-folds: First, it is necessary to raise the success rate of startups by means of the compatibility of the capital scale, low cost and life cycle of ideas. Second, the living lab for sharing ideas and collaboration is needed in the value chain system. Third, the living lab model is promoting rural community development and farm household income.

• Journal of Powder Materials
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• v.28 no.5
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• pp.410-416
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• 2021

Ti-6Al-4V alloy has a wide range of applications, ranging from turbine blades that require smooth surfaces for aerodynamic purposes to biomedical implants, where a certain surface roughness promotes biomedical compatibility. Therefore, it would be advantageous if the high volumetric density is maintained while controlling the surface roughness during the LPBF of Ti-6Al-4V. In this study, the volumetric energy density is varied by independently changing the laser power and scan speed to document the changes in the relative sample density and surface roughness. The results where the energy density is similar but the process parameters are different are compared. For comparable energy density but higher laser power and scan speed, the relative density remained similar at approximately 99%. However, the surface roughness varies, and the maximum increase rate is approximately 172%. To investigate the cause of the increased surface roughness, a nonlinear finite element heat transfer analysis is performed to compare the maximum temperature, cooling rate, and lifetime of the melt pool with different process parameters.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.2
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• pp.143-148
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• 2022

For the purpose of treating health checkups and recovery of patients in a super-aged society, hospitals use devices designed with a reduction circuit of electromagnetic waves associated with the specific absorption rate of electromagnetic waves absorbed by the human body. In this paper, we proposed a filter improvement design method capable of reducing electromagnetic waves. As a result of confirming the validity of the proposed technique through simulation and experimental results, the following result values were obtained. Applying the common-mode (CM) inductor 4 mH to a calibration circuit, noise decreased in a multiband spectrum. Using the differential mode(DM) inductor 40 µH element in the primary calibration circuit, the noise decreased by 15 dB or more in the 3 MHz band spectrum. Also, applying the Admittance Capacitance (Y-Cap) 10 nF element in the secondary calibration circuit resulted in the decrease by more than 30 dB in the band spectrum before 2 MHz. After using a common-mode inductor 4 mH element in the tertiary calibration circuit, it decreased by more than 15 dB in the band spectrum after 2 MHz.

• Agricultural and Biosystems Engineering
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• v.4 no.2
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• pp.50-57
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• 2003

This study was conducted to develop software which provides automatic site-specific field data acquisition, data processing, data mapping and management for precision agriculture. The developed software supports acquisition and processing of both digital and analog data streams. The architecture was object-oriented and each component in the architecture was developed as a separate class. In precision agriculture research, the laborious task of manual ground-truth data collection will be avoided using the developed software. In addition, gathering high-density data eliminates the need for interpolation of values for un-sampled areas. This software shows good potential for expansion and compatibility for variable-rate-application (VRA). The FIM (Field Information Management) computer program provides the user with an easy-to-follow process for field information management for precision agriculture.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.41-42
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• 2015

The concrete aggregate generates carbon dioxide in production but its demanding is gradually increased in accordance with the depletion of natural resources. Therefore we evaluated compatibility and basic physical properties of Silicon manganese slag generated in iron production as an applicable concrete aggregate. In our test, the silicon maganese slag shows 2.8g/㎥ of density in 10mm of maximum particle size similar to a natural aggregate, and its absorption rate was 0.3% similar to the electric furnace slag. Unit volume weight and ratio of absolute volume was respectively 2,001㎏/㎥ and 51%. Strength properties of Silicon manganese slag will be evaluated with further studies and experiments.

• Ceramist
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• v.21 no.3
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• pp.216-232
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• 2018

The average life span is over 80 years of age, and various biomaterials have being studied. Many research institutes and companies around the world have been commercializing bioactive glass through R&D, however, there is not much research in Korea. Most bioactive glass is applied to bone regeneration in powder form due to its excellent bio-compatibility. Recently, new applications such as scaffolds for tissue engineering and nerve regeneration have been found in composite form. The global market size is not as large as US $ 556 million in 2019, but the growth rate is very high at a CAGR of 14.35 %. This field is waiting for the challenge of new researchers.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.1
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• pp.128-133
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• 2010

The Titanium has many superior characteristics which are specific strength, heat resistance, corrosion resistance, organism compatibility, non-magnetic and etc. and their quantity are abundant. this study performed turning operation of Ti-6Al-4V alloy using the TiAlN Coated Tool which treated Physical Vapor Deposition. Experimental works are also executed to measure cutting force, tool wear, chip figuration and surface roughness for different cutting conditions. As a result of study. Cutting depth influences on the cutting force much more than the feed rate and the value of the cutting force is the most stable at the depth of 1.0mm. And tool wear was serious at over 100m/min of cutting speed and cutting condition was excellent at 1.0mm of cutting depth.

• Journal of the Korean Society of Tobacco Science
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• v.30 no.1
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• pp.25-32
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• 2008

In this study, we compared three different pretreatment methods, such as block digestion, microwave digestion and solvent injection, coupled with Octopole Reaction System(ORS)-ICP-MS was used for the quantification of heavy metals in mainstream smoke of 2R4F reference cigarette, and then evaluated those efficiencies in the recovery, repeatability and reproducibility. In all methods, volatile heavy metals, As, showed the highest CV value, and Cd showed the lowest one. However, the solvent injection method showed the most stable recovery rate and CV value of 2.36 %. This method showed also advantages in time-consuming and compatibility with ICP-MS system. This results demonstrate that solvent injection method can be recommended as a superior pretreatment procedure to be able to reduce contaminants and spectral interference as well as loss of the elements interested.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.11
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• pp.73-79
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• 2004

While CDMA systems are proven to be excellent solutions for cellular communications, they suffer from severe multi-path interferences and are unable to support high-data-rate transmissions over frequency-selective fading channels. This paper introduces a novel downlink transmission method for next generation mobile communication systems. The proposed method allows frequency-domain equalization at the receiver while maintaining the compatibility with the 3rdgeneration CDMA systems.