• Korean Journal of Applied Biomechanics
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• v.17 no.4
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• pp.149-156
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• 2007

The purpose of this study was to compare the world class women's hurdlers with kinematic variables Lee Yeon-Kyoung's in the 100m hurdle. Among korea elite female hurdler, Lee Yeon-Kyoung was participated as a subject. Eight JVC video cameras(GR-HD1KR) were used to film the performance of Lee Yeon-Kyoung at a frame rate of 60fields/s. The real-life three-dimensional coordinate data of digitized body landmarks were smoothed using a fourth order Butterworth low pass recursive digital filter with an estimated optimum cutoff frequency of 7.4Hz. After analyzing and comparing Lee Yeon Kyung's kinematic variables with the world top class hurdlers in the woman's 100m hurdle run, the following conclusions were obtained. 1. Lee should be able to increase the speed with over 5.4m/s from start to first hurdle and then maintain the speed range from 8.33m/s to 8.67m/s until 10th hurdle. Lee should have to maintain the speed with 8.51m/s from 10th hurdle to finish line. 2. Lee has to reach her maximum running speed at 5th hurdle and then has to shorten running time with 0.5sec between hurdles. 3. Lee should be able to run around 2.5sec from start to frist hurdle and then maintain under 1.00sec following phases. Lee should be able to maintain under 1.10sec from 10th hurdle to finish line. 4. Lee needs to control a consistent takeoff and landing distance pattern, Lee needs to lower the height of the center of gravity of the body with 0.33m when she clears the hurdles.

• Journal of the Korean Applied Science and Technology
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• v.37 no.3
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• pp.438-447
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• 2020

The critical micelle concentration (CMC) values of the mixed surfactant systems and the solubilization conatant (K_s) values of 4-ethylaniline in those solutions were measured and analyzed by the UV-Vis method. As a result, the mixed surfactant systems of TTAB/LSB and TTAB/TX-100 did not deviate significantly from ideal mixed micellization. However, the mixed systems of SDS/LSB and SDS/TX-100 showed great negative deviations from ideal mixed model. These differences showed that the intensity of the interaction between two components in the mixed micelle was different for each mixed system and that these differences greatly influenced the solubilization of 4-ethylaniline by a mixed surfactant system. Among pure surfactants, an anionic surfactant such as SDS showed a greater K_s value than other ionic surfactants, and the K_s value by each surfactant system decreased in the order of SDS≫TTAB≧LSB>TX-100. In addition, the K_s values of all the mixed surfactant systems were higher than those of the pure surfactants constituting the mixed systems.

• 전기의세계
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• v.28 no.4
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• pp.53-63
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• 1979

Interface recombination velocity in $Al_{x}$G $a_{1-x}$ As-GaAs and $Al_{0.85}$, G $a_{0.15}$ As-GaA $s_{1-y}$S $b_{y}$ heterojunction systems is studied as a function of lattice mismatch. The results are applied to the design of highly efficient III-V heterojunction solar cells. A horizontal liquid-phase epitaxial growth system was used to prepare p-p-p and p-p-n $Al_{x}$G $a_{1-x}$ As-GaA $s_{1-y}$S $b_{y}$-A $l_{x}$G $a_{1-x}$ As double heterojunction test samples with specified values of x and y. Samples were grown at each composition, with different GaAs and GaAs Sb layer thicknesses. A method was developed to obtain the lattice mismatch and lattice constants in mixed single crystals grown on (100) and (111)B oriented GaAs substrates. In the AlGaAs system, elastic lattice deformation with effective Poisson ratios .mu.$_{eff}$ (100=0.312 and .mu.$_{eff}$ (111B) =0.190 was observed. The lattice constant $a_{0}$ (A $l_{x}$G $a_{1-x}$ As)=5.6532+0.0084x.angs. was obtained at 300K which is in good Agreement with Vegard's law. In the GaAsSb system, although elastic lattice deformation was observed in (111) B-oriented crystals, misfit dislocations reduced the Poisson ratio to zero in (100)-oriented samples. When $a_{0}$ (GaSb)=6.0959 .angs. was assumed at 300K, both (100) and (111)B oriented GaAsSb layers deviated only slightly from Vegard's law. Both (100) and (111)B zero-mismatch $Al_{0.85}$ G $a_{0.15}$As-GaA $s_{1-y}$S $b_{y}$ layers were grown from melts with a weight ratio of $W_{sb}$ / $W_{Ga}$ =0.13 and a growth temperature of 840 to 820 .deg.C. The corresponding Sb compositions were y=0.015 and 0.024 on (100) and (111)B orientations, respectively. This occurs because of a fortuitous in the Sb distribution coefficient with orientation. Interface recombination velocity was estimated from the dependence of the effective minority carrier lifetime on double-heterojunction spacing, using either optical phase-shift or electroluminescence timedecay techniques. The recombination velocity at a (100) interface was reduced from (2 to 3)*10$^{4}$ for y=0 to (6 to 7)*10$^{3}$ cm/sec for lattice-matched $Al_{0.85}$G $a_{0.15}$As-GaA $s_{0.985}$S $b_{0.015}$ Although this reduction is slightly less than that expected from the exponential relationship between interface recombination velocity and lattice mismatch as found in the AlGaAs-GaAs system, solar cells constructed from such a combination of materials should have an excellent spectral response to photons with energies over the full range from 1.4 to 2.6 eV. Similar measurements on a (111) B oriented lattice-matched heterojunction produced some-what larger interface recombination velocities.ities.ities.s.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.8
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• pp.56-63
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• 2010

This work proposes a 12b 100MS/s 0.13um CMOS pipeline ADC for battery-powered mobile video applications such as DVB-Handheld (DVB-H), DVB-Terrestrial (DVB-T), Satellite DMB (SDMB), and Terrestrial DMB (TDMB) requiring high resolution, low power, and small size at high speed. The proposed ADC employs a three-step pipeline architecture to optimize power consumption and chip area at the target resolution and sampling rate. A single shared and switched op-amp for two MDACs removes a memory effect and a switching time delay, resulting in a fast signal settling. A two-step reference selection scheme for the last-stage 6b FLASH ADC reduces power consumption and chip area by 50%. The prototype ADC in a 0.13um 1P7M CMOS technology demonstrates a measured DNL and INL within 0.40LSB and 1.79LSB, respectively. The ADC shows a maximum SNDR of 60.0dB and a maximum SFDR of 72.4dB at 100MS/s, respectively. The ADC with an active die area of 0.92 $mm^2$ consumes 24mW at 1.0V and 100MS/s. The FOM, power/($f_s{\times}2^{ENOB}$), of 0.29pJ/conv. is the lowest of ever reported 12b 100MS/s ADCs.

• Journal of Bio-Environment Control
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• v.21 no.3
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• pp.228-235
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• 2012

This study was carried out to investigate the effect of irrigation methods for reducing a drainage on the growth and yield in rockwool (Grodan co.) and cocopeat (chip : dust = 50 : 50 included fiber) culture. The nutrient solution was irrigated by $100J{\cdot}cm^{-2}$-100 mL, $50J{\cdot}cm^{-2}$-45 mL, $50J{\cdot}cm^{-2}$-40 mL, $50J{\cdot}cm^{-2}$-35 mL ($100{\sim}50J{\cdot}cm^{-2}$-100~35 mL, Nutrient solution 100~35 mL was irrigated per plant when the accumulated radiation was $100{\sim}50J{\cdot}cm^{-2}$). The drain rates per plant of 100-100, 50-45, 50-40, 50-35 were 26.3%, 8.8%, 6% 4.4% and 23.1%, 7.5%, 5% 3.4% in rockwool and cocopeat slabs. The water contents and EC of 100-100 and 50-45 were managed by the 55~70%, $3.0{\sim}5.0dS{\cdot}m^{-1}$ which were good condition for paprika culture in rockwool and cocopeat slabs, while those of 50-40 and 50-35 were managed by beyond 50%, $4.5{\sim}9.5dS{\cdot}m^{-1}$. The plant height, number of branches and leaf size of 100-100 and 50-45 were similarly increased while those of 50-40 and 50-35 were decreased. The fruit size and weight of 50-40 and 50-35 were small and light, while those of 100-100 and 50-45 were similarly big and heavy. The marketable fruits of 100-100 and 50-45 treatments were similarly more by 9.7~9.8 in rockwool and 8.8~8.9 in cocopeat, while the unmarketable fruits, the small and blossom end rot fruits were increased in 50-40 and 50-35 treatments. The yield of 100-100 and 50-45 treatments were similarly high.

• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.581-586
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• 2014

The most stable adsorption structures and their corresponding energies of 4-pyridone, 4-hydroxypyridine, 2-pyridone and 2-hydroxypyridine have been investigated by Density Functional Theory (DFT) calculation and high-resolution photoemission spectroscopy (HRPES). We confirmed that between the two reaction centers of 4- and 2-pyridone, only O atom of carbonyl functional group can act as a Lewis base while both the two reaction centers of 4- and 2-hydroxypyridine (tautomers of 4- and 2-pyridone) can successfully function as a Lewis base. On the other hand, owing to their molecular structures, there is a remarkable difference between the adsorption structures of 4- and 2-hydroxypyridine. Through the analysis of the N 1s and O 1s core level spectra obtained using HRPES, we also could corroborate that two different adducts coexist on the surface at room temperature due to their activation energy investigating the coverage dependent variation of bonding configurations when these molecules are adsorbed on the Ge(100) surface.

• Journal of Korean Neurosurgical Society
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• v.39 no.4
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• pp.271-276
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• 2006

Objective : Despite the recent progress that has been made in intracerebral monitoring, it is still difficult to quantify the exact extent of primary brain damage after severe head injury. In this work, we investigate the role of S-100B protein as a serum marker of brain damage after severe head injury. Methods : 21 patients with severe head injury [GCS score <9] were selected for this prospective study. A venous blood sample was taken as soon as possible after head injury and the serum concentration of S-100B protein was measured daily for five consecutive days. The serum level of S-100B protein was compared with the patients' outcome. The outcome was measured twice, at hospital discharge and after 6 months of follow-up using the Glasgow Outcome Scale[GOS]. Results : Those patients who died within two weeks [after head injury] had a significantly higher serum S-100B value than those who survived [median, 9.64ug/L versus 2.91ug/L]. Seven [78%] of the nine patients who died had a maximum S-100B value of 2ug/L or higher, while three [25%] of the twelve surviving patients showed a maximum S-100B protein value of more than 2ug/L [P<005]. Conclusion : These results indicate that S-100B protein appears to be the most reliable index for estimating the extent of brain damage.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.2
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• pp.207-216
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• 1995

Flow and heat transfer characteristics of mixed convection heat transfer in a rectangular en-closure with various outlets are numerically investigated. The parameters considered here include Reynolds number, Grashof number and the position of outlet. The results show streamlines, isotherms, Nusselt numbers, velocity and temperature distributions. It has been shown that as Reynolds number increases, the size of cell decreases at Re$\leq$100 and increases at Re>100 for $Gr=10^4$. There is a minimum size of cells at Re=100, $Gr=10^4$. The maximum mean Nusselt number occurs at Re=400, $Gr=10^4$ and one right outlet. The mean Nusselt numbers can be formulated by the correlation equation $Nu=C{\cdot}Gr^a{\cdot}Re^b$.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.37-39
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• 2011

IHO has been developing S-100 and S-101 based on international standards. According to development It is expected to have a effect on the system which can be used to display information of ENC. In this study, S-100 standard completed is reviewed and S-101 in the second phase is analyzed. In conclusion, we organized the trends of S-100 and S-101 standard and the ripple effect into the system used ENC.

• Journal of Navigation and Port Research
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• v.44 no.5
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• pp.375-381
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• 2020

The IMO has established a regulation for the ECDIS installation on ships based on the IHO S-57 standards. The ECDIS supports sailors in achieving a safe voyage by using ENCs and monitoring the information of their ship. However, the S-57 standards were developed as edition 3.1 and prohibited revision for more than 20 years. So, the IHO developed a new standard as S-100 into the hydrography and maritime field instead of updating the S-57 to edition 4.0. In this study, the new S-100 ECDIS was developed and verified with ENCs and the digital maritime safety information by using a ship steering simulator and by conducting an on-board sea-trial test. It evaluated the impact on ship operations if the next-generation navigation support system is introduced. Based on this research, the S-100 ECDIS will generate improvements such as safe voyages by providing various of real-time safety information and up-to-date data to ship and sailors.