• Journal of Advanced Navigation Technology
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• v.15 no.2
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• pp.281-286
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• 2011

Data sorting is one of important pre-process to utilize huge data in modern society, but sorting spends a lot of time by sorting itself. In this paper, we presented hybrid sorting algorithm that splits array to sort concurrently in CPU and GPU. To do this, we decided most effective range of array based on hardware performance, then accomplished reducing whole sorting time by concurrent sorting on CPU and GPU. As shown in results of experiment, hybrid sorting improved about eight percent of sorting time in comparison with the sorting time using only GPU.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.618-620
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• 1997

A $50{\times}50{\mu}m^2$ aluminum micromirror array is fabricated using shadow evaporation process. The fabrication process is very simple with use of shadow evaporation process, and the micromirror array has a high fill-factor. The static and dynamic characteristics such as deflection angle vs. applied voltage, step response, and frequency response are measured using a contact free optical measurement technique. The downward threshold voltage was 8 V, step response time was $13.5{\mu}s$ when 32 V step voltage applied, and a resonance observed at 11kHz. The lifetime of micromirror with anti-stiction coating was tested and micromirror operated successfully over 200 million cycles of touch-down operations.

• Journal of the Semiconductor & Display Technology
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• v.21 no.4
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• pp.71-76
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• 2022

We evaluated and developed a 6th generation large-size polisher in the type of face-up and Oscar. We removed the hillocks of the low temperature poly-silicon (LTPS) thin film with this polisher. The surface roughness of LTPS was lowered from 7.9 nm to 0.6 nm after CMP(chemical mechanical polishing). The thickness of the LTPS is measured through reflectance in real time during polishing, and the polishing process is completed according to this thickness. The within glass non-uniformity (WIGNU) was 6.2% and the glass-to-glass non-uniformity (GTGNU) was 2.5%, targeting the LTPS thickness of 400Å. In addition, the residual slurry after the CMP process was removed through the Core Flow PVA Brush and alkaline chemical.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2279-2282
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• 2007

Highly crystalline, uniform Fe nanoparticles were successfully synthesized and encapsulated in zirconia shell using sol-gel process. Two different approaches have been employed for the coating of Fe nanoparticle with zirconia. The thickness of zirconia shell can be readily controlled by altering molar ratio of Fe nanoparticle core to zirconia precursor in the first case where as reaction time was found to be most effective parameter to controlled the shell thickness in the second method. The structure and magnetic properties of the ZrO2-coated Fe nanoparticles were studied. TEM and HRTEM images show a typical core/shell structure in which spherical α-iron crystal sized of ~25 nm is surrounded by amorphous ZrO2 coating layer. TGA study showed an evidence of weight loss of less than 2% over the temperature range of 50-500 °C. The nanoparticles are basically in ferromagnetic state and their magnetic properties depend strongly on annealing temperature. The thermal treatment carried out in as-prepared sample resulted in reduction of coercivity and an increase in saturation magnetization. X-ray diffraction experiments on the samples after annealing at 400-600 °C indicate that the size of the Fe@ZrO2 particles is increased slightly with increasing annealing temperature, indicating the ZrO2 coating layer is effective to interrupt growing of iron particle according to heat treatment.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.199-202
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• 1999

Many processing times for fabricating complex shaped parts by near net shape process such as thixoforming or semi-solid forming, are required due to the time for die design, induction heating and forming process. Therefore, for the thixoforming process, multi-capacity induction heating process is very important due to the reduction of the processing time and cost. It is indispensable to adopt a power-time heating pattern which manages to conciliate complete eutectic melting at the core with limited overheating at the periphery. The total reheating time is thus dependent on billet diameter; in inches$(pm20%)$. Typically, high frequency is used for the rapid reheating of the billet to the eutectic temperature range and low frequency for the remelting of the desired fraction of liquid and for the radial homogeneization of the liquid fraction. So in this study, the multi-capacity induction heating conditions of ALTHIX 86s alloy to reduce the processing time and cost would be proposed. The suitability of multi-capacity induction heating conditions would be verified through the comparison to Garat's data.

• Nuclear Engineering and Technology
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• v.53 no.6
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• pp.1731-1735
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• 2021

The operation of the nuclear reactor requires accurate and fast methods and techniques for analysing its kinetics. These techniques become even more important when the MOX-fuel is used due to the lower value of delayed neutron fraction 𝛽 for ²³⁹Pu. Based on a Birth-and-Death process review, the mathematical model of thermal reactor core has been proposed different from existing ones. The analytical method for thermal point-reactor parameters evaluation is described within this work. The proposed method is applied for analysis of the unsteady transient processes taking place in a thermal reactor at its start-up or shutdown power change, as well as during small accidental power variation from the rated value. Theoretical determination of MASURCA reactor core reactivity through the analysis of experimental data on neutron time spectra was made.

• Korean Journal of Construction Engineering and Management
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• v.5 no.2 s.18
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• pp.194-201
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• 2004

Core-wall construction method is applied in many high-rise building constructions. This is caused by the advantages of the method such as the effect of saved construction cost and shortened period. However, the analysis study of planning practice for core-wall construction shows matters take place during core-wall construction, such as increasing in construction cost and period. These matters result from the limited work space leading to low productivity, the activity interference leading to increasing in period, additional temporary work cost and time, and delayed concrete pour activity. A large part of these can be prevented taking place by very detailed and most careful core-wall construction plan. Therefore, this study suggests improvement directions of core-wall construction planning process focused on the cooperation system of a contractor between a sub-contractor and the process.

• Korean Journal of Materials Research
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• v.34 no.7
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• pp.370-376
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• 2024

In this study, we report significant improvements in lithium-ion battery anodes cost and performance, by fabricating nano porous silicon (Si) particles from Si wafer sludge using the metal-assisted chemical etching (MACE) process. To solve the problem of volume expansion of Si during alloying/de-alloying with lithium ions, a layer was formed through nitric acid treatment, and Ag particles were removed at the same time. This layer acts as a core-shell structure that suppresses Si volume expansion. Additionally, the specific surface area of Si increased by controlling the etching time, which corresponds to the volume expansion of Si, showing a synergistic effect with the core-shell. This development not only contributes to the development of high-capacity anode materials, but also highlights the possibility of reducing manufacturing costs by utilizing waste Si wafer sludge. In addition, this method enhances the capacity retention rate of lithium-ion batteries by up to 38 %, marking a significant step forward in performance improvements.

• 연구논문집
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• s.34
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• pp.121-129
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• 2004

The influence of powder size and ball-milling time on the magnetic properties of $Fe_{73}Si_{16}B_7Nb_3Cu_1$ nanocrystalline alloy powder was investigated. Flake-shaped powders were produced by pulverizing the ribbons annealed at $550^\circC$ for 1 hour. The powders were classified and consolidated into core shapes at a pressure of 18ton/$cm^2$. The initial permeability at 100kHz of the inductor core produced using $53-75\mum$ powders showed the highest value although its consolidated density showed the lowest one. The reason for the result is due to the cracking of the particles larger than $75\mum$ during the consolidation process. The ball-milling of powders for 2-4 hours improved the consolidation density and the initial permeability of the cores. The intrinsic coercivity of the powder decreased as well, resulting from the stress relief of the powder by a short-time milling.

• Nuclear Engineering and Technology
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• v.51 no.2
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• pp.377-383
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• 2019

Targeting at simulating the application of thorium-uranium (TU) fuel in the CANDU-6 reactor, this paper analyzes the process using the code DRAGON/DONJON where the discrete TU fuel pins are applied in the CANDU-6 reactor under the time-average equilibrium refueling. The results show that the coolant void reactivity of the assembly analyzed in this paper is lower than that of 37-element bundle cell with natural uranium and 37-element bundle cell with mixed TU fuel pins; that the max time-average channel/bundle power of the core meets the limits - less than 6700kW/860 kW; that the fuel conversion ratio is higher than that of the CANDU-6 reactor with natural uranium; and that the exit burnup increases to 13400 MWd/tU. Thus, the simulation in this paper with the fuel in the 37-element bundle cell using discrete TU fuel pins can be considered to be applied in CANDU-6 reactor with adequate modifications of the core structure and operating modes.