• East Asian mathematical journal
• /
• v.29 no.5
• /
• pp.529-536
• /
• 2013

In this paper, we find the values and the number of occurrences of each value of the cross-correlation function $C_d({\tau})$ when $d=\frac{2^{k-1}}{2^s-1}(2^{k(i+1)}-2^{ki}+2^{s+1}-2^k-1)$, where n = 2k, s is an integer such that 2s divides k, and i is odd.

• Journal of the Korean Chemical Society
• /
• v.44 no.3
• /
• pp.281-285
• /
• 2000

• Proceedings of the KAIS Fall Conference
• /
• 2008.11a
• /
• pp.339-342
• /
• 2008

Methacrylate와 Cyclopentadiene을 반응하여 5-methylbicyclo[2.2.1]hept-2-ene-5-carboxylate (MBHC)를 합성하고 만들어진 MBHC를 Column Chromatography를 이용하여 Endo와 Exo를 분리하였고, MBHC에 붙는 작용기에 따른 수율 및 Endo, Exo의 비율을 확인하였다.

• Journal of Radiation Protection and Research
• /
• v.37 no.2
• /
• pp.90-95
• /
• 2012

A radio-tracer experiment was performed in a greenhouse to investigate the effectiveness of the simultaneous application of K and Ca as a countermeasure for reducing the radiocaesium and radiostrontium uptake by rice. Paddy soil (loam of pH 6.5) in soil boxes was spiked with $^{137}Cs$ and $^{85}Sr$, and treated with K and Ca in the forms of KCl and $Ca(OH)_2$, respectively, at agrochemical grades before transplanting. For the seeds of the control plants, soil-to-plant transfer factors (TF, $m^2\;kg^{-1}-dry$) of $^{137}Cs$ and $^{85}Sr$ were $7.4{\times}10^{-5}$ and $2.1{\times}10^{-4}$, respectively, whereas the corresponding values for the straws were $2.6{\times}10^{-4}$ and $2.2{\times}10^{-2}$, respectively. The TF values of $^{137}Cs$ and $^{85}Sr$ kept decreasing as the level of the simultaneous application of K and Ca (K/Ca, $g\;m^{-2}$) increased up to 33.6/322 and 48.0/460, respectively. The maximum rate of the decrease was around 60% for both radionuclides. Nearly 60% reduction in the TF value of $^{85}Sr$ was observed even at the dosage of 33.6/322, which was considered the optimum dosage based on crop productivity as well as reduction in the radiocaesium and radiostrontium uptake by rice. The optimum dosage may depend on various factors so further experiments need to be made for many different conditions.

• Journal of Korean Society for Quality Management
• /
• v.48 no.1
• /
• pp.13-27
• /
• 2020

Purpose: The purpose of this study is to present a recoil measurement and analysis of K2 rifle for the development of a virtual reality marksmanship training in the Republic of Korea Army. Methods: For the recoil measurement, a test-bed is built by a barrel that has exact dimensions of K2 rifle and three piezoelectric pressure sensors mounted on the barrel. Data of over 200 rounds of 5.56mm M193 and K100 bullets are collected and analyzed from live fire experiments. For the recoil analysis, both the free recoil method and the gas exhaust aftereffect method are used to calculate a recoil velocity, momentum and kinetic energy of K2 rifle by applying the law of conservation of momentum. In addition, a new method is proposed that uses the third law of motion and the chamber pressure model for the recoil measurement Results: The results show how different between the previous and proposed methods with respect to M193 and K100 bullets of K2 rifle. In M193, the free recoil method demonstrates 1.113, 4.197, and 2.335, the gas exhaust aftereffect method computes 1.698, 6.407, and 5.441, and the proposed method calculates 0.990, 3.734, and 1.848 in recoil velocity, momentum and kinetic energy, respectively. In K100, the free recoil method demonstrates 1.190, 4.487, and 2.669, the gas exhaust aftereffect method computes 1.776, 6.699, and 5.949, and the proposed method calculates 1.060, 3.998, and 2.119 in recoil velocity, momentum and kinetic energy, respectively. Conclusion: This study implements live fire experiments to provide recoil velocity, momentum, and kinetic energy of K2 rifle using both M193 and K100 bullets. For the development of the army virtual reality marksmanship, the results in this paper would be useful to design and produce a gun and/or a rifle of virtual reality.

• Clinical and Experimental Reproductive Medicine
• /
• v.24 no.2
• /
• pp.267-271
• /
• 1997

Apoptosis, programmed cell death, is posulated to occur in granulosa cells in ovarian follicular atresia. bcl-2 gene serves as protector from apoptosis and, thus, is associated with increased cell survival. TRPM-2 gene expression has been implicated as a trigger of apoptosis in rat prostate, uterus and mammary gland. Our objective was to determine if bcl-2 and TRPM-2 are expressed in luteinized human GC and, therefore, have regulatory functions for apoptosis in GC. Human GC were obtained via oocyte retrival from the infertile patients stimulated with exogeneous gonadotropins while undergoing IVF. GC were isolated from follicular fluid using Percoll gradient centrifugation. The GC were further purified with anti-CD45 magnetic beads to remove contaminating WBC's. RT-PCR were performed to analyze the mRNA expression of bcl-2 and TRPM-2 in the GC. The PCR primers were designed to amplify a 195 bp fragment of bcl-2 and a 174 bp fragment of TRPM-2. The PCR products were electrophoresed on 4% agarose gel. Three separate experiments indicated that both bcl-2 and TRPM-2 are concurrently expressed in human GC. We cultured granulosa cells with FSH (1 ng/ml) for 1 day to investigate the relative changes of TRPM-2 mRNA level with RNAse protection assay. When we cultured GC with serum free medium for 1 day TRPM-2 mRNA level increased with 1.3 fold, however it was decreased 0.64 fold with FSH. Therefore we conclude that bcl-2 and TRPM-2 are concurrently expressed and that the interaction of their products may be involved in GC apoptosis. And TRPM-2 may be regulated with FSH.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2002.02a
• /
• pp.168-170
• /
• 2002

Magnetization studies were conducted on a single crystal of $YNi_{2}$$B_{2}$C superconductor. The 17 mg crystal was studied at temperatures T from above $T_{c}$ (15.5 K) to 3 K, in the magnetic fields H // c-axis up to 6 tesla. The crystal exhibited little magnetic irreversibility, with a critical current density $CO_{3}$ ~ $10^{-4}$ $\times$ $CO_{3}$, the depairing current density. Near $T_{c}$, the equilibrium magnetization M was London-like with M $\infty$ In(H). The upper critical field $H_{c2}$ of the single crystal $YNi_{2}$$B_{2}$C was estimated by the several alternative approaches such as standard London limit, Ginzburg-Landau, and Abrikosov relations. The estimated $H_{c2}$values agree relatively well with each other approaches.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.45 no.12
• /
• pp.83-88
• /
• 2008

The QPP interleaver has been gaining attention since it provides contention-free interleaving functionality for high speed parallel turbo decoders. In this paper we first show that the quadratic term $f_2x^2%K$ of $f(x)=(f_1x+f_2x^2)%K$, the address generating function, is periodic. We then introduce a low-power address generator which utilizes this periodic characteristic. This generator follows the conventional method to generate the interleaving addresses and also to save the quadratic term values during the first half of the first period. The saved values are then reused for generating further interleaved addresses, resulting in reduced number of logical operations. Power consumption is reduced by 27.38% in the design with fixed-K and 5.54% in the design with unfixed-K on average for various values of K, when compared with the traditional designs.

• Journal of Integrative Natural Science
• /
• v.4 no.3
• /
• pp.177-181
• /
• 2011

The catalytic dehydrocoupling of bis(1-sila-3-butyl)benzene 1 and 2-phenyl-1,3-disilapropane 2 by $Cp_2ZrCl_2$/Red-Al and $Cp_2ZrCl_2$/n-BuLi was reported to compare their catalytic efficiency. The dehydrocoupling of monomeric silanes 1 with the $Cp_2ZrCl_2$/Red-Al and $Cp_2ZrCl_2$/n-BuLi combination catalysts produced two phases of polymers: one is a highly cross-linked insoluble solid, and the other is noncross-linked or slightly cross-linked soluble oil and could be a precursor for the solid polymer. The dehydrocoupling of 2 with the $Cp_2ZrCl_2$/n-BuLi combination catalyst similarly produced two phases of polymers. By contrast, the catalytic reaction of 2 with the $Cp_2ZrCl_2$/Red-Al combination catalyst produced a soluble polymer via redistribution/dehydrocoupling process.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2010.04a
• /
• pp.403-407
• /
• 2010

건축 구조재료로 사용되는 소나무의 화재조건을 알아보기 위하여 콘칼로리미터(ISO 5660-1)를 이용하여 연소성질을 분석하였다. 자연 건조된 소나무에 $(NH_4)_2SO_4$, $NH_4H_2PO_4$, $(NH_4)_2HPO_4$ 등의 암모늄염을 이용하여 난연성을 부가하였다. 소나무의 함수율은 10.2%였으며 초기 열방출 곡선은 $(NH_4)_2HPO_4$인 경우 완만하게 증가하였으며 가장 좋은 난연성을 보였다. $HRR_{peak}$ 값은 무처리된 경우 $217\;kW/m^2$, $(NH_4)_2SO_4$, $NH_4H_2PO_4$, $(NH_4)_2HPO_4$인 경우에는 각각 $190\;kW/m^2$, $188\;kW/m^2$, $166\;kW/m^2$로 나타났다. 즉 $(NH_4)_2HPO_4$로 처리된 경우 23.5%의 감소현상이 관찰되었다. $HRR_{peak}$ 도달 시간은 무처리된 시험편(290s) 및 $(NH_4)_2SO_4$, $NH_4H_2PO_4$, $(NH_4)_2HPO_4$으로 처리된 시험편은 각각 298s, 263s, 313s로 나타났다. 연기 발생속도는 사용한 암모늄염 중 $(NH_4)_2SO_4$로 처리된 시험편이 가장 작게 관찰되어 저발연성 감연제 역할을 하는 것으로 판단된다.