• Transactions of the Society of Information Storage Systems
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• v.2 no.2
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• pp.150-155
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• 2006

Vertical L/UL (Load/Unload) velocity is very important parameter to determine the L/UL performance, and the vertical velocity is determined by the actuator velocity and the ramp profile. However, it is not easy to precisely control the actuator rotating velocity during the L/UL process. Especially in emergency parking, servo system doesn't operate, it is impossible to control an actuator velocity. Then, the vertical unloading velocity depends on only ramp profile. The ramp height and the sliding length for L/UL process in SFF (Small Form Factor) HDD are restricted due to slimness and small media. For these reasons, it is very difficult to design the ramp profile in SFF HDD. Therefore, this study analyzes the unloading dynamic characteristics for various ramp profiles and makes the thesis for ramp profile design.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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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.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.17 no.2
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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.

• The Korean journal of internal medicine
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• v.39 no.2
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• pp.215-227
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• 2024

Asthma is characterized by airway obstruction and inflammation, and presents significant diagnostic and treatment challenges. The concept of endotypes has improved understanding of the mechanisms of asthma and has stimulated the development of effective treatment strategies. Sputum profiles may be used to classify asthma into two major inflammatory types: type 2-high (T2H) and type 2-low (T2L) asthma. T2H, characterized by elevated type 2 inflammation, has been extensively studied and several effective biologic treatments have been developed. However, managing T2L is more difficult due to the lack of reliable biomarkers for accurate diagnosis and classification. Additionally, conventional anti-inflammatory therapy does not completely control the symptoms of T2L; therefore, further research is needed to identify effective biologic treatments. This review provides new insights into the clinical characteristics and underlying mechanisms of severe T2L and investigates potential therapeutic approaches to control the disease.

• Annals of Pediatric Endocrinology and Metabolism
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• v.23 no.4
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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.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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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.

• Journal of Korea Foundry Society
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• v.10 no.6
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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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• v.7 no.2
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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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• v.14 no.3
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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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• v.12 no.1
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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.