• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.6
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• pp.8-13
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• 2015

Recently, Illumination industry of LED module has been focused to industry technology for energy conservation of nation. The LED device is excellent to power efficiency due to semiconductor light source element. And the application to the lighting circuit technology can be designed to the sensitive lighting system for human sensitivity control. In this paper, as a process for analyzing the operating temperature of standardized electronic device including LED device has analyzed about fusing character with in designed micro fuse for electronic device protection from the over current. Using the de-rating technique, which is performed to micro fuse fusing test in the range of $-30^{\circ}C{\sim}120^{\circ}C$ thermostatic chamber. To the output data in each temperature zone, it is performed to first-order linear fitting. Additionally, applying the resistance temperature coefficient and statistical data for the reliable analysis has derived to the metal element resistance of micro fuse with temperature change of the thermostatic chamber. As a research result, The changed temperature effect of thermostatic chamber was confirmed regarding fusing time change.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.4
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• pp.225-230
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• 2004

An electromagnetic actuator has been designed and fabricated for Probe-based data storage applications. The actuator consists of permanent magnets(SmCo) housing and a media Platform which is connected to the Si frame by four couples of Si leaf springs. In order to generate electromagnetic force, Cu coils were electroplated under the media platform. The magnetic field distribution was calculated with 3D Finite Element Method of Maxwell 3D program. The field strength felt by Cu coils was estimated to be about 0.33T when the distance between the media platform and permanent magnets is $200\mu\textrm{m}$. The static and dynamic motions of the actuator were analyzed by FEM method with ANSYS 5.3. The measured displacements of the actuator were about $\pm$$92\mu\textrm{m}$ for input current of $\pm$40㎃ and the resonance frequency was 100Hz. The proposed electromagnetic actuator can be utilized for media driver of probe-based data storage system.

• Journal of Wellbeing Management and Applied Psychology
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• v.4 no.3
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• pp.23-33
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• 2021

Purpose: In the course of the domestic environmental impact assessment, the current status survey was improperly conducted, and the issue of false and inaccurate environmental impact assessment reports has been raised several times recently through media reports. Research design, data and methodology: There is a continuous demand for improvement measures for the current status measurement method, such as having difficulties in securing a normal measurement date in consideration of equipment operation and rainfall days in the field. Results: In addition, in order to grasp the general air quality status of the evaluation target area, it is necessary to check the various current status concentrations by season and time series per year. However, there is a problem that is currently being carried out based on limited results such as measurement for 1 day or 3 days. Conclusions: Therefore, in this study, based on the national atmospheric measurement network, an inverse distance weighted (IDW) interpolation method was applied to calculate the current state concentration. This study suggested a method to use it in preparing the air quality item in the environmental impact assessment report.

• PNF and Movement
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• v.17 no.3
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• pp.441-450
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• 2019

Purpose: This study identified the co-activation of quadriceps and hamstring muscles during hamstring strengthening exercises in healthy adults. Methods: Twenty-one participants were required for the present study design to achieve 80% power, 0.8 effect size (η2), and an alpha level of 0.05. Thus, this study recruited 21 healthy adults. All participants performed Nordic exercises, bridge exercises, and one-leg deadlifts randomly. The activity of the rectus femoris, vastus medialis (VM), vastus lateralis (VL), biceps femoris (BF), and semitendinosus (SM) were measured. In addition, the ratios of VM/VL and hamstring/quadriceps (HQ) were measured during the three hamstring strengthening exercises using electromyography. One-way ANOVA was used to compare the co-activation of quadriceps and hamstring muscles in the three exercises. Results: The activity of VM and VL during the performance of one-leg deadlifts was significantly higher than the other two exercises. The BF had significantly higher activity during the Nordic exercises compared to the other two exercises. In addition, the SM activation was significantly greater during Nordic exercises than one-leg deadlifts. Additionally, there was significant difference in HQ ratio among hamstring strengthening exercises. In specific, the one-leg deadlifts yielded a significantly lower HQ ratio. Conclusion: This study revealed that one-leg deadlifts are effective in rehabilitation for anterior cruciate ligament injury. In addition, Nordic exercises can be recommended to facilitate hamstring muscle activation.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.329-329
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• 2022

Accurate characterization of terrestrial precipitation variation from high spatial resolution satellite sensors is beneficial for urban hydrology and microscale agriculture modeling, as well as natural disasters (e.g., urban flooding) early warning. However, the widely-used top-down approach for precipitation retrieval from microwave satellites is limited in several hydrological and agricultural applications due to their coarse spatial resolution. In this research, we aim to apply a novel bottom-up method, the parameterized SM2RAIN, where precipitation can be estimated from soil moisture signals based on an inversion of water balance model, to generate high spatial resolution terrestrial precipitation estimates at 0.01º grid (roughly 1-km) from the C-band SAR Sentinel-1. This product was then tested against a common reanalysis-based precipitation data and a domestic rain gauge network from the Korean Meteorological Administration (KMA) over central South Korea, since a clear difference between climatic types (coasts and mainlands) and land covers (croplands and mixed forests) was reported in this area. The results showed that seasonal precipitation variability strongly affected the SM2RAIN performances, and the product derived from separated parameters (rainy and non-rainy seasons) outperformed that estimated considering the entire year. In addition, the product retrieved over the mainland mixed forest region showed slightly superior performance compared to that over the coastal cropland region, suggesting that the 6-day time resolution of S1 data is suitable for capturing the stable precipitation pattern in mainland mixed forests rather than the highly variable precipitation pattern in coastal croplands. Future studies suggest comparing this product to the traditional top-down products, as well as evaluating their integration for enhancing high spatial resolution precipitation over entire South Korea.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.1
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• pp.201-210
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• 1994

A theoretical heat-flow model incorporating with a constant moving CO$_{2}$ laser beam has been analyzed to predict depth and the shape of bead section during last beam welding. The laser beam is exponentially attenuated with an abosrption coefficient in the material. The solution can be expressed in terms of normalized variables. The experimental data were generated by usint CW 2 CO$_{2}$ laser with multi beam mode and CW 3 kW CO$_{2}$laser with Gaussian mode. The specimens were made as bead-on-plate welds for SM 10C, STS 304, STS 316, STS 420 and pure Nickel. The maximum possible penetration depth and the shape of beas section for given sources of laser power, travel speed and beam spot size can be prdicted with this model in a given material.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.2
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• pp.120-123
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• 1998

Based on the co-linearity in the Triticeae, comparative RFLP analysis of 2M chromosome of Ae. comosa Sibth et Sm. was performed with 2MS and 2M additional lines of Triticum aestivum L. cv. Chinese Spring. Among the wheat RFLP probes conserved in the short arms of wheat chromosome 2, those above psr912 were located on the long arms of 2M in Aegilops comosa. The rest probes on the short arm and all the probe sequences on the long arm of group 2 chromosome in wheat were conserved on the equivalent chromosomal position in Aegilops comosa. So, it is apparent that some chromosomal segment from the short arm had been transferred to long arm while reconstructing 2M chromosome relative to wheat chromosomes. The break-point was located between psr912 and psr131 of the short arm. This rearrangement of chromosome 2M might be a molecular evidence of the M genome speciation from an ancestral type.

• Journal of the Korean Ceramic Society
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• v.40 no.4
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• pp.360-364
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• 2003

Effects of sintering time upon the structures and microwave dielectric characteristics of co-substituted $Ba_{6-3x}$/S $m_{8+}$2x/ $Ti_{18}$ $O_{54}$ ceramics (x=2/3) were investigated. Prolonged sintering had significant effects upon the qf value and temperature coefficient, and a high Qf value (10,600 GHz) was obtained in the present ceramics combined with high-$\varepsilon$ (80) and near-zero temperature coefficient.t..

• Journal of Ocean Engineering and Technology
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• v.5 no.2
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• pp.85-93
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• 1991

피로 파괴연구의 급격한 발전에 따라 최근의 기계나 구조물들은 많은 분야에서 손상허용설계원리에 근거하여 설계되고 있다. 이러한 상황 하에서 피로파손의 정확한 특성을 밝히는 것은 신뢰성을 고려한 기계나 구조물의 설계에 있어 가장 중요한 요인이 된다. 피로파손은 많은 랜덤요소를 내포하고 있으므로 실험결과 분석 및 수명예측을 분석하기 위해서는 통계학적 해석이 요구되고 있다. 본 연구의 목적은 회전굽힘피로시험을 수행하고 피로수명을 분석하는데 정규분포, 대수분포, 지수분포 및 Weibull분포를 이용하여 실험결과와 비교하고 파손확률을 찾는데 있다.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.6
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• pp.87-95
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• 1995

In order to predict the case depth and case width in laser transformation hardening, a finite element method was used to analyze the temperature distribution on the material. Laser hardening of the specimens of SM45C and STE11steels was experimented by using the continuous wave CO$_{2}$ laser with the various travel speeds and the defocused Gaussian beam mode. Phosphate coating was adopted on the surface of SM45C to increase the absorption of 10.6 .mu. m laser energy. Experimental data show good agreement with the theoretical predictions. The maximum possible case depth can be predicted for the given laser hardening conditions, such as laser power, and travel speed.