• Journal of Embryo Transfer
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• v.10 no.3
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• pp.203-208
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• 1995

This study was carried out to efficiently use the ultrarapid freezing method in the cryopreservation of mouse ova. For this, the effects of dehydration method, oval vigour and $0^{\circ}C$ controlling method on post-thawing viability were investigated. Fresh mouse ova were dehydrated in mPBS with 3.5M DMSO and /or 0.25M sucrose, and directly immersed in L$N_2$ for ultrarapidly freezing. The frozen ova were thawed at 37$^{\circ}C$, rehydrated in mPBS with 0.25M sucrose, and then repeatedly washed in HAM's Fl0 before evaluating the morphological normality of frozen-thawed ova. The results obtained showed that there was difference between treatments in a experiment. 1) The post-thawing viability of ova dehydrated in multi-step (48.4$\pm$13.8%) was higher than that of ova in two-step (40.9$\pm$14.0%). 2) The post-thawing viability of fertilized ova (87$\pm$14.0%) was significantly(p<0.0l) higher than that of unfertilized ova (5.4$\pm$5.4%). 3) The post-thawing viability of ova dehydrated and rehydrated using a cooling machine (95.8$\pm$4.2%) was significantly(p<0.05) higher than that on ice(84.1$\pm$9.9). In conclusion, in order to efficiently cryopreserve ova in vitro with ultrarapidly freezing method, highly viable embryos should be selected, heavy osmotic shock to the dehydrating ova should be avoided, and embryos in high osmotic condition were dehydrated and rehydrated in a constantly low temperature.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.6 no.1
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• pp.32-43
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• 1996

A $CdIn_{2}Te_{4}$ single crystal was grown by modified veritical bridgman method. The $CdIn_{2}Te_{4}$ single crystal was evaluated to be tetragonal by the powder method. The $CdIn_{2}Te_{4}$ single crystal was confirmed to be grown with its c axis along the lengthe of the boule by the Laue reflection method. Hall effect of $CdIn_{2}Te_{4}$ single crystal was estimated by van der pauw method from 293 K to 30 K. Hall data of the sample perpendicular to c axis was $n=8.75{\times}10^{23}electrons/m^{3},\;R_{H}=7.14{\times}10^{-5}m^{3}/C,\;{\sigma}=176.40{\omega}^{-1}m^{-1},\;{$\mu}=3.41{\times}10^{-2}m^{2}/V.s$ and the sample parallel to c axis was $n=8.61{\times}10^{23}electrons/m^{3},\;R_{H}=7.26{\times}10^{-5}m^{3}/C,\;{\sigma}=333.38{\omega}^{-1}m^{-1}\;and\;{$\mu}=2.42{\times}10^{-2}m^{2}/V.s$ for room temperature. The value of Hall coefficient on sample perpendicular or parallel to c axis were positive. There $CdIn_{2}Te_{4}$ single crystal was p-type semiconductor.

• Journal of Powder Materials
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• v.13 no.4 s.57
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• pp.278-284
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• 2006

Spherical Ag powder was prepared in the system of $AgNO_3\;and\;NaBH_4$ by wet chemical reduction method. The size of Ag powder was increased as the reaction temperature and the concentration of reducing agent was decreased in the constant concentration of dispersion agent. Optimum conditions of producing Ag powder having $1.39{\mu}m$ of D50 was 1M of $AgNO_3$, 0.5M of $NaBH_4$, 1.5g of Gelatine in the room temperature.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.3
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• pp.273-277
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• 1981

This study was carried out in 1979 to establish the proper mulching culture method for an aromatic tobacco, ST 375-4. Three different methods of mulching were employed: Improved mulching (I. M.), General mulching (G. M.) and Non-mulching (N. M.). The number of seedlings per hole was 5 for I. M., and one for G. M. and N. M. In comparison with N. M., I. M. had shortened final date of leaf harvest by 14 days, enabling curing leaves before the rainy season. It also reduced transplanting labour hours by 44.9%. Yield and price value increased with improved mulching culture. There was little difference in relative light intensity at leaves between N. M. and I. M.

• Communications of the Korean Mathematical Society
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• v.26 no.4
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• pp.695-708
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• 2011

Based on the multiple-time-scale (MTS) method, a general formula has been presented for solving an n-th, n = 2, 3, ${\ldots}$, order ordinary differential equation with strong linear damping forces. Like the solution of the unified Krylov-Bogoliubov-Mitropolskii (KBM) method or the general Struble's method, the new solution covers the un-damped, under-damped and over-damped cases. The solutions are identical to those obtained by the unified KBM method and the general Struble's method. The technique is a new form of the classical MTS method. The formulation as well as the determination of the solution from the derived formula is very simple. The method is illustrated by several examples. The general MTS solution reduces to its classical form when the real parts of eigen-values of the unperturbed equation vanish.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.2
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• pp.172-179
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• 2016

For an evaluation of service life in RC(Reinforced Concrete) structures, deterministic method and probabilistic method considering random variables of design parameters are usually adopted. In the work, surface chloride contents which vary with distance from sea shore and height are investigated from the previous research literature surveys, and they are considered for service life estimation. Through the analysis, the probabilistic method shows much lower results, which is due to variations of design parameters and very low intended durability failure. In the deterministic method, the structures within 250m and higher than 60m are evaluated to be free from chloride attack. In the probabilistic method, those higher than 60m in all the region and higher than 40m and 250m from sea shore are evaluated to satisfy the service life.

• The KIPS Transactions:PartC
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• v.18C no.1
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• pp.1-6
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• 2011

The performance and practicality of cryptosystem for encryption, decryption, and primality test is primarily determined by the implementation efficiency of the modular exponentiation of $a^b$(mod n). To compute $a^b$(mod n), the standard binary squaring still seems to be the best choice. But, the d-ary, (d=2,3,4,5,6) method is more efficient in large b bits. This paper suggests m-numeral system modular exponentiation. This method can be apply to$b{\equiv}0$(mod m), $2{\leq}m{\leq}16$. And, also suggests the another method that is exit the algorithm in the case of the result is 1 or a.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.457-458
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• 2010

• Journal of Digital Convergence
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• v.12 no.4
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• pp.251-257
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• 2014

In u-Healthcare environment, large amounts of important vital information is processed through M2M(Machine to Machine). M2M is configured by wireless networks and has several problems for limited bandwidth and low reliability. Therefore, in this paper is proposed a method called uHLZW(u-Healthcare LZW) to improve channel efficiency to solve such problem. uHLZW algorithm has high compression ratio for vital data. The results showed that the average compression ratio of uHLZW got from 1.6 times to 4.0 times better than existing methods(Huffman and LZW compression).

• Journal of Powder Materials
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• v.22 no.4
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• pp.260-265
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• 2015

Spherical fine cobalt powders were fabricated by new liquid reduction method. Commercial cobalt sufate heptahydrate was used as raw material. Also ethylene glycol was used as solvent and hydrazine-sodium hypophosphite mixture was used as reduction agent for the new liquid reduction method. A plate shaped cobalt powders with an approximately 300 nm were prepared by a traditional wet ruduction method using distilled water as solvent and hydrazine. Spherical fine cobalt powders with an average size of $1-3{\mu}m$ were synthesized by a new liquid reduction method in 0.3M cobalt sulfate and 1.5M hydrazine-0.6M sodium hypophosphite mixture at 333K.