• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.245-248
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• 1997

The dielectric resonators(DRs) with dielectric properties are widely used in microwave integrated circuit(MICs) and monolithic microwave integrated circuits(MMICS). The variational method as numerical simulation scheme would be applied to calculate the resonant frequencies(fr) and Q-factors of microwave dielectric resonators. The dielectric resonator with a cylindrical “puck” structure of high dielectric material is modeled in this simulation. The parameters, such as the diameter, the height, and the dielectric constant of dielectric resonator, would determine the resonant frequency and the Q-factor. The relationship between these parameters would effect each other to evaluate the approximate resonant frequency. This simulation method by the variational formula is very effective to calculate fr, and Q-factor. in high frequency microwave dielectric resonator The error rate of the simulation results and the measured results would be considered to design the microwave dielectric resonators.

• Journal of Welding and Joining
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• v.16 no.5
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• pp.86-92
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• 1998

High speed wire seam weldability of tin coated thin gage sheet steels was investigated. Thickness and coating weight ranges of the test materials were 0.21~0.35mm and 1.1/1.1~2.8/11.2g/$m^2$, respectively. Test results indicated that the surface roughness value, Rz decreased as increasing the coating weight. The Rz was thought to be one of the important factors to influence the optimum welding condition range, $\triangle$Q. The $\triangle$Q showed close relationship with welding conditions such as welding pressure and travel speed. Higher welding pressure widened the $\triangle$Q while higher travel speed reduced the $\triangle$Q value. Results also demonstrated that tin coating weight should be optimized based on the weldability or the serviceability after welding. At th HAZ of sheet materials with thinner coating layer, tin depleted zone was produced since molten film of the coating material on the base metal agglomerated by the surface tension, which could result in reducing the corrosion resistance of the HAZ in the service environment.

• Korean Journal of Microbiology
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• v.38 no.4
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• pp.254-259
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• 2002

A psychrotrophic bacterium was isolated from Antarctic marine sediment and identified as Shewanella sp. species based on the biochemical properties and 16S rRNA sequence, and designated as Shewanella sp. L93. Extracellular protease produced by this strain was purified through ammonium sulfate precipitation, High-Q column chromatography, first gel permeation chromatography, BioScale Q2 ion exchange chromatography and second gel permeation chromatography, and basic properties of this enzyme were investigated.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.5
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• pp.407-413
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• 2014

The diesel engine and reduction gear combination is one of the common propulsion system in a naval vessel. Since the diesel engine has torsional vibration caused by reciprocating motion of the mass and gas pressure force of the cylinder, high cycle torsional fatigue can be occurred. Therefore, ROK navy restricts the maximum stress of the propulsion shaft according to MIL G 17859D. In this paper, the root cause for the failure of the diesel engine and reduction gear connecting shaft occurred in typical naval vessel is investigated based on the measured bending and torsional moment according to MIL G 17859D procedure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.258-258
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• 2007

일반적인 CMOS공정으로는 높은 주파수 대역에서 높은 Q factor를 갖는 인덕터를 구현하는데 어렵고 이에 반해 RF ICs는 갈수록 high Q를 가지는 인덕터가 요구되고 있다. 이를 LTCC 기판 위에 인덕터를 구현했을 때 놓은 주파수 대역에서 성능을 알아보기 위해 모의 실험하였고, 실제로 구현을 하여 측정결과를 비교해 보았다. LTCC 기판위에 인덕터를 구현 하였을 때 실리콘, 유리 기판위에 인덕터를 구현하였을 때보다 더 높은 Q 값을 측정할 수 있었다. 5GHz 대역에서 실리콘, 유리, LTCC 기판에서 각각 12, 33, 51에 값을 확인할 수 있었다.

• Journal of Korean Society of Forest Science
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• v.96 no.3
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• pp.290-294
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• 2007

Interspecific hybrid seedlings by artificial crossing of Genus Quercus (Q. serrata, Q. dentata, Q. mongolica var. crispula, Q. aliena) were planted at nursery in Tottori University. Seedlings of hybrids by natural crossing(Q. fabri and $Q.{\times}mccormickii$) were selected and planted at Hiruzen district in Tottori University. Artificial interspecific hybrid $F_1$ and natural hybrid $F_1$ bloomed when they were 4 years old and 3 years old, respectively. The pollen fertility and seed viability were investigated from the bloomed individuals in 2001. The germination percentages of the pollens of artificial interspecific hybrid were more than 84% except one individual, and the extension of pollen tubes was normal. The normal seed percentages of artificial interspecific hybrid were more than 90% similar to parents. Germination percentages of normal seed of natural crossing family were more than 64%, respectively, and selfed offsprings of Q. fabri, and $Q.{\times}mccormickii$ hade high reproductive ability.

• Journal of Biomedical Engineering Research
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• v.43 no.1
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• pp.19-26
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• 2022

The Comprehensive in vitro Proarrhythmic Assay(CiPA) project was launched for solving the hERG assay problem of being classified as high-risk groups even though they are low-risk drugs due to their high sensitivity. CiPA presented a protocol to predict drug toxicity using physiological data calculated based on the in-silico model. in this study, features calculated through the in-silico model are analyzed for correlation of changing action potential in the near future, and features are verified through predictive performance according to drug datasets. Using the O'Hara Rudy model modified by Dutta et al., Pearson correlation analysis was performed between 13 features(dVm/dtmax, APpeak, APresting, APD90, APD50, APDtri, Ca_peak, Ca_resting, CaD90, CaD50, CaDtri, qNet, qInward) calculated at 100 pacing, and between dVm/d_{tmax_repol} calculated at 1,000 pacing, and linear regression analysis was performed on each of the 12 training drugs, 16 verification drugs, and 28 drugs. Indicators showing high coefficient of determination(R²) in the training drug dataset were qNet 0.93, AP resting 0.83, APDtri 0.78, Ca resting 0.76, dVm/dt_max 0.63, and APD90 0.61. The indicators showing high determinants in the validated drug dataset were APDtri 0.94, APD90 0.92, APD50 0.85, CaD50 0.84, qNet 0.76, and CaD90 0.64. Indicators with high coefficients of determination for all 28 drugs are qNet 0.78, APD90 0.74, and qInward 0.59. The indicators vary in predictive performance depending on the drug dataset, and qNet showed the same high performance of 0.7 or more on the training drug dataset, the verified drug dataset, and the entire drug dataset.

• Nutrition Research and Practice
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• v.7 no.4
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• pp.309-314
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• 2013

This study was conducted to investigate the relationship among the current status of calcium intake from milk and milk products, physical growth and bone mineral density in 664 male and female middle school and high school students aged 15-17 years. In the study, the current status of calcium intake from milk and milk products was analyzed, and the height, body composition, and bone mineral density of the right heel bone (calcaneus) were measured. The daily calcium intake of milk and milk products was calculated as the 'dairy equivalent of calcium', which is the calcium content in 200 mL of white milk. The cutoffs of tertiles of the dairy equivalent of calcium were calculated and then the subjects were categorized into 3 groups according to the tertiles, Q1 group (lower intake group), Q2 group (middle intake group) and Q3 group (upper intake group). The daily calcium intake of milk and milk products in Q1, Q2 and Q3 groups was 16.2 mg, 99.7 mg, and 284.0 mg, respectively, and the ratio of milk and milk product consumption to the daily total calcium intake was 5.4%, 27.4%, and 49.7%, respectively. The ratio of total calcium intake to the daily recommended intake in study subjects was 30.5% in Q1, 42.3% in Q2, and 60.7% in Q3, with significant differences (P < 0.05). Height, body weight, BMI, and % of body fat in three tertile groups (Q1, Q2 and Q3) were not significantly different. However, the T scores for bone mineral density in female students in three tertile groups (Q1, Q2 and Q3) was significantly different (P < 0.05). The study showed that the intake of milk and milk products in adolescents, particularly in girls, can improve the bone mineral density without increasing body weight, and thus confirmed that milk intake is important in adolescence.

• The Journal of Information Systems
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• v.29 no.2
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• pp.131-147
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• 2020

Purpose The purpose of this study is to develop intelligent vehicle parking distribution system based on LoRa network at the circumstance of traffic congestion during cultural festival in a local city. This paper proposes a parking dispatch and distribution system using a Q-learning algorithm to rapidly disperse traffics that increases suddenly because of in-bound traffics from the outside of a city in the real-time base as well as to increase parking probability in a parking lot which is widely located in a city. Design/methodology/approach The system get information on realtime-base from the sensor network of IoT (LoRa network). It will contribute to solve the sudden increase in traffic and parking bottlenecks during local cultural festival. We applied the simulation system with Queuing model to the Yudeung Festival in Jinju, Korea. We proposed a Q-learning algorithm that could change the learning policy by setting the acceptability value of each parking lot as a threshold from the Jinju highway IC (Interchange) to the 7 parking lots. LoRa Network platform supports to browse parking resource information to each vehicle in realtime. The system updates Q-table periodically using Q-learning algorithm as soon as get information from parking lots. The Queuing Theory with Poisson arrival distribution is used to get probability distribution function. The Dijkstra algorithm is used to find the shortest distance. Findings This paper suggest a simulation test to verify the efficiency of Q-learning algorithm at the circumstance of high traffic jam in a city during local festival. As a result of the simulation, the proposed algorithm performed well even when each parking lot was somewhat saturated. When an intelligent learning system such as an O-learning algorithm is applied, it is possible to more effectively distribute the vehicle to a lot with a high parking probability when the vehicle inflow from the outside rapidly increases at a specific time, such as a local city cultural festival.

• Korean Journal of Optics and Photonics
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• v.31 no.6
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• pp.328-333
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• 2020

In this paper, we study the analysis method for the aspherical tolerance of a Korsch telescope using a Q polynomial. It is important to analyze the tolerances for evaluating quality in high-precision fabrication of aspherical reflectors for high-resolution satellites. Thus we express the aspheric surface in terms of a Q polynomial in which each coefficient term is composed independently, and analyze the tolerance of a Korsch telescope. We also analyze the tolerance using Zernike fringe sag, which expresses the shape error of an aspherical mirror. By comparing the two results, we confirm that the Q-polynomial method can be used to analyze an aspherical mirror.