• Asian-Australasian Journal of Animal Sciences
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• v.8 no.1
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• pp.29-35
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• 1995

A selection experiment with Romney Marsh sheep was used to evaluate correlated responses to selection. The selected flock was formed in 1979 by the Romney Group Breeders where selection was for prolificacy, defined as the number of live lambs born per ewe joined per year and a randomly selected control flock was established in 1982. Selection for prolificacy resulted in (i) increased ewe fertility, (ii) increased ewe ovulation rate, (iii) increased ewe litter size, (iv) decreased ewe body weight, (v) decreased lamb birth weight and (vi) decreased lamb 8-week weight. The rates of correlated responses per year respectively for ewe fertility, ewe ovulation rate, ewe litter size, ewe body weight, lamb birth weight and lamb 8-week weight were 0.033(0.002), 0.043(0.016), 0.019(0.005), -0.017(0.066), -0.055(0.025) and -0.150(0.057).

• Journal of the Korean Vacuum Society
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• v.6 no.1
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• pp.50-60
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• 1997

Undoped, cobalt-doped and erbium-doped $ZnAl_2S_4, ;ZnAl_2Se_4, ;CdAl_2S_4, ;and;CdAl_2Se_4$ single crystals were grown by the chemical transport reaction method. The crystal structures, the lattice constants, the optical energy gaps, and the photoluminescence properties of these single crystals were investigated. Also, the optical transition mechanisms by the impurities of cobalt and erbium were identified from these results.

• YAKHAK HOEJI
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• v.18 no.4
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• pp.243-248
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• 1974

Nine benzoxazolin-2-thione derivatives were sunthesized as the potential antimicrobial substances. These compounds were tested for the antimicrobial activities using Staphylococcus aureus and Escherichia coli by way of tube dilution method. The three compounds of I, II and VII omjoboted the growth of S.aureus at the concentration of 1${\mu}$g/ml, and III,VI,VIII and IX exhibited considerable antimicrobial activities against S. aureus at the concentration of 10.m.u.g/ml. As to the growth of E. Coli, VII VII and VIII inhibited at the concentration of 1${\mu}$g/,l. II,III and IV exhibited considerable antimicrobial activities against E. coli at the concentration of 10${\mu}$g/ml.

• Archives of Pharmacal Research
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• v.10 no.2
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• pp.142-147
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• 1987

Fourteen kinds of medicinal plants were screened for determining inhibitory activities on monoamine oxidase B. The extracts of Artemisia Messer-Schmidtiana (herba), Chrysanthemum indicum(flos), Ericibe obtusifolia (radix et rhizoma) and Sophora japonica (flos) strongly inhibited the enzyme. Among them, Chrysanthemi flos was chosen for elucidating its active principles, and some flavonoids were isolated and identified as acasetin (I), 5, 7-dihydroxy chromone (II), diosmetin (III), apigenin (IV), eriodictyol (V) and luteolin (VI).$IC_{50} were determined as following: 1, 2.46;II, 0.19; III, 2. 11mM, and the others showed weak inhibition.

• Bulletin of the Korean Chemical Society
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• v.15 no.9
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• pp.729-732
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• 1994

The acid-promoted cleavage of the E-and Z-isomers of 1-phenyl-6-neopentyl-1,3,4-trimethyl-1-silacyclohe x-3-ene(II) under various conditions gave clean and nearly quantitative formation of the ring-opened 2,3,7,7-tetramethyl-5-(X)silyl-1-octene products (X=OMe, Cl, OH). The possible mechanism for the formation of the ring-opened products was suggested that the initial protonation of II at C-4 would give a carbocation oriented so that they are ${\beta}$ to the silicon atom, and the subsequent nucleophilic attack at silicon would give rise to the observed products (VI, VII, VIII).

• Korean Journal of Environment and Ecology
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• v.11 no.3
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• pp.290-309
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• 1997

To investigate the plant community structure in Gunpo Experimental Forest of Mt. Suri, Kyonggi-do, sixty-four plots were set up and surveyed. By DCA ordination technique, sixty-four plots were divided into seven groups. The dividing groups were * Pinus rigitaeda community, P. densiflora community, P. densiflora-Quercus mongolica community, Q. variabilis community, Q. aliena comunity, Q. serrata community, Carpinus laxiflora community. Though the successional trend of seven communities by DCA ordination technique and DBH class distribution analysis was not clearly inferred, * Pinus rigitaeda community and P. densiflora-Q: mongolica community seems to be trended from present state to Q. spp. community. P. densiflora community, Q. variabilis community, Q. aliena community and Q. serrata community seems to be maintained preaent state and C. laxiflora community will be maintainde stable state. Shannon's diversity was 0.7430~1.3025(unit area: 300m$^{2}$) and soil acidity was pH 4.16~5.13 in surveyed areas.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.4
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• pp.414-418
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• 2016

In this paper, a hardware architecture of low area gradient magnitude calculator is proposed. For the hardware complexity reduction, the characteristic of orthogonal projection vector and hardware resource sharing technique are applied. The proposed hardware architecture can be implemented without degradation of the gradient magnitude data quality since the proposed hardware is implemented with original algorithm. The FPGA implementation result shows the 15% of logic elements and 38% embedded multiplier savings compared with previous work using Altera Cyclone VI (EP4CE115F29C7N) FPGA and Quartus II v15.0 environment.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.191.2-191.2
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• 2015

Details of carrier dynamics in self-assembled quantum dots (QDs) with a particular attention to nonradiative processes are not only interesting for fundamental physics, but it is also relevant to performance of optoelectronic devices and the exploitation of nanocrystals in practical applications. In general, the possible processes in such systems can be considered as radiative relaxation, carrier transfer between dots of different dimensions, Auger nonradiactive scattering, thermal escape from the dot, and trapping in surface and/or defects states. Authors of recent studies have proposed a mechanism for the carrier dynamics of time-resolved photoluminescence CdTe (a type II-VI QDs) systems. This mechanism involves the activation of phonons mediated by electron-phonon interactions. Confinement of both electrons and holes is strongly dependent on the thermal escape process, which can include multi-longitudinal optical phonon absorption resulting from carriers trapped in QD surface defects. Furthermore, the discrete quantized energies in the QD density of states (1S, 2S, 1P, etc.) arise mainly from ${\delta}$-functions in the QDs, which are related to different orbitals. Multiple discrete transitions between well separated energy states may play a critical role in carrier dynamics at low temperature when the thermal escape processes is not available. The decay time in QD structures slightly increases with temperature due to the redistribution of the QDs into discrete levels. Among II-VI QDs, wide-gap CdZnTe QD structures characterized by large excitonic binding energies are of great interest because of their potential use in optoelectronic devices that operate in the green spectral range. Furthermore, CdZnTe layers have emerged as excellent candidates for possible fabrication of ferroelectric non-volatile flash memory. In this study, we investigated the optical properties of CdZnTe/ZnTe QDs on Si substrate grown using molecular beam epitaxy. Time-resolved and temperature-dependent PL measurements were carried out in order to investigate the temperature-dependent carrier dynamics and the activation energy of CdZnTe/ZnTe QDs on Si substrate.

• Journal of environmental and Sanitary engineering
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• v.15 no.1
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• pp.25-33
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• 2000

The new ion exchange resin was synthesized from chloromethylated styrene-1,4-divinylbenzene(DVB) with 1-aza-15-crown-5 macrocyclic ligand by substitution reaction. The effect of pH, time, dielectric constant of solvent and cross-linked of the matrix on the adsorption for $UO_2^{2+}$, $Ca^{2}$ and $Lu^{3+}$ was investigated. The metal ion was not adsorbed on the resins below pH 3 but above pH 4 fast adsorption behavior was showed. The optimum equilibrium time for adsorption of metallic ions was two hours. The adsorption selectivity determined in ethanol matrix was in increasing order $UO_2^{2+}>Ca^{2}>Lu^{3+}$. The adsorption power was in the order of 1%, 2%, 10% and 20% -crosslinked resin, but adsorption properties of resins decreased in proportion to the order of dielectric constant of solvents used. In addition, these metal ions could be separated in the column packed with 1% crosslinked resin by pH2.5 $HNO_3$ as an eluent.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.340-341
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• 2013

양자점(Quantum dots; QDs)은 단전자 트랜지스터, 레이저, 발광다이오드, 적외선 검출기와 같은 고효율 광전소자 응용을 위해 활발한 연구가 진행되고 있다. II-VI 족 화합물 반도체는 III-V 족 화합물 반도체와 비교했을 때 더 큰 엑시톤 결합에너지(exciton binding energy)를 가지는 우수한 특성을 보이고 있으며 이러한 성질을 가지는 II-VI 족 화합물 반도체 중에서도 넓은 에너지 갭을 가지는 CdTe 양자점은 녹색 영역대의 광전자 소자로서 활용되고 있다. 기존의 CdTe/ZnTe 양자점을 성장하기 위해 ZnTe와 격자부정합이 적은 GaAs 기판을 이용한 연구가 주를 이룬 반면 Si기판을 이용한 연구는 미흡하다. 하지만 Si 기판은 GaAs 기판에 비해 값이 싸고, 여러 분야에 응용이 가능하며 대량생산이 가능하다는 이점을 가지고 있어 초고속, 초고효율 반도체 광전소자의 제작을 가능케 할 것으로 기대된다. 또한 양자점의 고효율 광전소자에 응용을 위해서는 Si 기판 위에 양자점의 크기를 효율적으로 조절하는 연구 뿐 아니라 양자점의 크기에 따른 운반자 동역학에 대한 연구도 중요하다. 본 연구에선 분자선 에피 성장법(Molecular Beam Epitaxy; MBE)과 원자층 교대 성장법(Atomic Layer Epitaxy; ALE)을 이용하여 Si 기판 위에 성장한 CdTe/ZnTe 양자점의 크기에 따른 광학적 특성을 연구하였다. 저온 광 루미네센스(PhotoLuminescence; PL) 측정 결과 양자점의 크기가 증가함에 따라 더 낮은 에너지영역으로 피크가 이동하는 것을 확인하였다. 그리고 온도 의존 광루미네센스 측정 결과 양자점의 크기가 증가함에 따라 열적 활성화 에너지가 증가하는 것을 관찰하였는데, 이는 양자점의 운반자 구속효과가 증가하였기 때문이다. 또한 시분해 광루미네센스 측정 결과 CdTe/ZnTe 양자점의 크기가 증가함에 따라 소멸 시간이 긴 값을 갖는 것을 관찰하였는데, 이는 양자점의 크기가 증가함에 따라 엑시톤 진동 세기가 감소하였기 때문이다. 이와 같은 결과 Si 기판 위에 성장한 CdTe/ZnTe 양자점의 크기에 따른 열적 활성화 에너지와 운반자 동역학에 대해 이해 할 수 있었다.