• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.314-317
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• 2005

There are many benefits such as increased areal density, reduced power consumption, applied smaller size and improved shock resistance in Load/Unload(L/UL) mechanism. It has been the key technology of developing small form factor hard disk drive used in portable digital devices. The main objectives of L/UL are no slider-disk contact and faster L/UL process. For realizing those, we must consider many design parameters in L/UL systems. In this paper, we focus on the effects of ramp profile. We can investigate dynamic characteristics of suspension tap and slider on ramp during unloading process experimentally. In special, we examine the effects of vortical velocities, ramp slopes and disk vibrations. As the result of these experiments, we propose design criteria of advanced ramp profile for good unloading performance.

• 한국압력기기공학회 논문집
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• 제17권2호
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• pp.126-136
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• 2021

During operation of nuclear power plants, the fatigue assessment should be conducted repeatedly, considering changes of operating environments. For the case that cumulative usage factors (CUFs) may exceed the acceptance limit, flaw tolerance evaluation can be an alternative method to meet the regulatory requirements. In this respect, this paper analyzes the effects of the input variables for flaw tolerance evaluation based on ASME BPVC Section XI Appendix L. The reference analysis is performed for the example problem in NUREG/CR-6934. Then effects of the crack orientation, stress intensity factor solutions, thermal stress profiles, fatigue stress decomposition and fatigue crack growth curves are considered for the sensitivity analysis. The results show that the stress analysis considering the actual environment plays a crucial role in flaw tolerance evaluation.

• Annals of Pediatric Endocrinology and Metabolism
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• 제23권4호
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• pp.210-214
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• 2018

Purpose: Premature adrenarche (PA) often leads to polycystic ovary syndrome (PCOS). Higher anti-mullerian hormone (AMH) levels are reported in PCOS. We studied the androgen profile and AMH profiles in Hispanic girls with PA (aged 5-8 years) and age and body mass index (BMI) matched controls. Methods: Retrospective review of electronic medical records of girls who met the inclusion criteria for premature adrenarche were done. Results: PA girls (n=76) were matched to control girls (n=12) for age (mean${\pm}$standard deviation) ($6.7{\pm}1years$ vs. $6.2{\pm}1.3years$) and BMI ($20{\pm}10kg/m^2$ vs. $17.8{\pm}2.7kg/m^2$). Dehydroepiandrostenedione sulfate ($63.3{\pm}51.3{\mu}g/dL$ vs. $29.8{\pm}17.3{\mu}g/dL$, P<0.001) and testosterone levels ($11.4{\pm}4.8ng/dL$ vs. $8.2{\pm}2.9ng/dL$, P=0.001) were significantly higher in the PA group than controls. AMH values (<14 years: reference range, 0.49-3.15 ng/mL) were $3.2{\pm}2.2ng/mL$ vs. $4.6{\pm}3.2ng/mL$ respectively in the PA and control groups and were not different (P=0.4). AMH did not show a correlation with bone age (P=0.1), and testosterone (P=0.9) in the PA group. 17-hydroxyprogesterone levels (17-OHP ng/dL) were $39.5{\pm}30.5ng/dL$ vs. $36.8{\pm}19.8ng/dL$ in PA versus control girls. The concentration of 17-OHP was not statistically different between the control and PA groups. Conclusion: Higher AMH was not observed in PA girls and no correlation with BA and androgen levels was observed.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.80.2-81
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• 2003

Since hot peppers (Capsicum annuum L.) are getting reputation as an important source of vitamins, medicine and many other areas, consumption and cultivation is being increased in the world. In spite of this usefulness, so little attention has been given to the hot pepper plants. To date, less than 500 nucleotide sequences including redundancy has been identified in NCBI database. Therefore we started to EST sequencing project for initial characterization of the genome, because of the large genome size of hot pepper (2.7 3.3 ${\times}$ 109 bp), To date, a set of 10,000 non-redundant genes were identified by EST sequencing for microarray-based gene expression studies. At present, cDNA microarrays containing 4,685 unigene clones are used for hybridization labeled targets derived from pathogen infected and uninoculated leaf tissues. Monitoring of gene expression profiles of hot pepper interactions with soybean pustule pathogen (Xag；Xanthomonas axonopodis pv. glycine) will be presented.

• 한국주조공학회지
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• 제10권6호
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• pp.520-527
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• 1990

In order to reduce segregation in 12%Cr steel ingots of 60-100tons, numerical analysis by computer was applied to simulate solidification profiles and the profiles of liguid-solid coexisting zone in accordance with the ratios of H(Height) /D(diameter) of 100-ton ingot. The result is that the ratio of L(vertical length) /D(diameter) of liquid-solid coexisting zone was reduced in proportion to the decrease of H/D ratio. With the reduced H/D ratio(0.92) of ingot, the segregation in 60-ton ingot of 12% Cr steel can be much reduced and recovery was also improved by reducing ingot weight.

• Wind and Structures
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• 제7권2호
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• pp.131-144
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• 2004

A technique for the simulation of atmospheric boundary layers in wind tunnels is developed and tested experimentally. The device consists of a grid made of seven horizontal and vertical evenly distributed bars in which air injection holes are drilled in order to influence the flow in the wind tunnel. The air flow in each bar can be controlled independently. Firstly, the device is used together with a rough carpet, which covers the test section floor, in order to simulate the boundary-layer characteristics over an open rural area. Hot-wire measurements, performed at different positions in the test-section, show the capability of the grid in generating the required boundary layer. An acceptable agreement with statistical values of mean velocity and turbulence profiles has been achieved, together with a good span-wise homogeneity. The results are also compared with those of a passive simulation technique based on the use of spires.

• Food Science and Biotechnology
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• 제14권3호
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• pp.328-333
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• 2005

Finite difference model and dynamic thermal property evaluation system were developed to estimate convection heat transfer coefficient by modeling temperature-time profile of beef cube in continuous flow sterilizing system. As input parameters of the model, specific heat and thermal conductivity values of beef frankfurter meat were independently measured from 20 to $80^{\circ}C$. Convection heat transfer coefficient was estimated by comparing simulated and measured temperature-time profiles. Actual temperature-time profiles of meat cube were measured at flow rates of 15, 30, and 45 L/min and viscosities from 0 to 15 cp, and mean values of convection heat transfer coefficients ranged from 792 to $2107\;W/m^2{\cdot}K$. Convection heat transfer coefficient increased with increase in flow rate and decreased as viscosity increased.

• Journal of Magnetics
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• 제12권1호
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• pp.31-34
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• 2007

The Co-based ribbons with different length were annealed in different magnetic field and GMI profiles were investigated in order to clarify the influence of ribbon size on GMI effect. The GMI ratio decreased with the decreasing in length and also decreased with increasing annealing field. While, the slope of GMI profiles inclined and the field range showing linearity was broadened. It shows prospect to low field sensor, especially for a navigation sensor.

• Geomechanics and Engineering
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• 제18권1호
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• pp.1-9
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• 2019

In this study, both 2D and 3D failure shapes of rock mass above the water-filled cavity are put forward when the surrounding rock mass cannot bear the pressure caused by the water-filled cavity. Based on the analytical expressions derived by kinematic approach, the profiles of active and passive failure patterns are plotted. The sensitivity analysis is conducted to explore the influences of different rock parameters on the failure profiles. During the excavation of the deep tunnels above the karst cavity, the water table always changes because of progressive failure of cavity roof. Therefore, it is meaningful to discuss the effects of varying water level on the failure patterns of horizontal rock layers. The changing laws of the scope of the failure pattern obtained in this work show good consistency with the fact, which could be used to provide a guide in engineering.

• Journal of Pharmaceutical Investigation
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• 제23권3호spc1호
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• pp.9-18
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• 1993

Sugar spheres loaded with melatonin (MT) were coated with $Aquacoat^{\circledR}$ to control the release rate of MT over 8 hours. A zero-order release pattern over 8 hours was obtained with 20% coating on 8-10 mesh beads in USP basket dissolution studies. MT in 20% coated beads was quite stable at room temperature with less than 5% MT degraded during 6 months' storage. Dissolution profiles were also unchanged after 6 months. An oral preparation containing MT-loaded uncoated beads for immediate release and 20% coated beads with $Aquacoat^{\circledR}$ for controlled release over 8 hours was evaluated in six human subjects. When total 0.5 mg MT as low dose (immediate release portion of MT, 0.1 mg) was administered to four subjects, average peak plasma MT concentration was reached at about 600 pg/ml and maintained at about 10 pg/ml over 8 hours. Plasma MT concentration-time profiles were similar in shape to computer-simulated profiles. However, maximal plasma MT concentrations were three times greater compared to computer simulated curve. These results suggest that MT dose, ratio of immediate and controlled release MT, and pharmacokinetic parameters selected are adjusted to mimic endogenous MT concentration-time curve. In another study, 0.2 mg MT having 10% of immediate release portion and 80% controlled release portion produced plasma MT concentration-time curve which is more similar to endogenous profiles. A low bioavailability (<20%) may result from extensive first pass metabolism and remaining amounts of MT from controlled beads. A good correlation between plasma MT concentration and urinary excretion rate of 6-sulphatoxymelatonin (6-STMT), a major metabolite of MT was observed. As plasma MT concentration increased, urinary excretion rate of 6-STMT increased concomitantly. The linear relation between plasma MT and urinary excretion rate of 6-STMT was statistically significant. This result suggests that urinary 6-STMT may be used as an index of circadian rhythms of MT in humans.