• Journal of the Korean Mathematical Society
• /
• 제37권3호
• /
• pp.463-471
• /
• 2000

A central limit theorem is obtained for stationary linear process Xt = aj$\varepsilon$t-j, where {$\varepsilon$t} a strictly stationary associated sequence with Et < and {aj} is a sequence of real numbers with <. A functional central limit theorem is also derived.

• The Korean Journal of Mycology
• /
• 18권2호
• /
• pp.96-101
• /
• 1990

This study was conducted to select the promising antifungal microoganisms for biological control of wet bubble, Mycogone perniciosa. Ninty one isolates of fungi, 342 isolates of bacteria, and 556 actinomycetes were isolated from mushroom composts and soils, were subjected to primary screening test on agar medium base for their antimicrobial spectra. Among them, 12 bacteria and 71 actinomycetes were selected. Among the antibiotic producing microoganisms, 5 cultures were selected on the basis their antibiotic activities on casing soil with Benlate nontolerence M. perniciosa. Finally, AJ-117, AJ-136 and AK-139 were selected as microoganism with antifungal activity against two strains of M. perniciosa.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• 제23권8호
• /
• pp.988-995
• /
• 2019

In this paper, we propose the Tile Based Frequency Hopping - Chirp Spread Spectrum(TBFH-CSS) technique, which has excellent Low Probability of Intercept(LPI)/Anti-Jamming(AJ) performance. Conventional Frequency Hopping - Chirp Spread Spectrum(FH-CSS) technique uses only single chirp signal, that makes the follower jammer easy to find and jam. However, proposed TBFH-CSS uses various kind of chirp signals which are generated according to the structure of basis tile, it is composed the basis time unit and the basis bandwidth unit. The TBFH-CSS signal has variety signal period and signal bandwidth. Therefore, the follower jammer hard to find and difficult to jam the TBFH-CSS signal. We analysis the LPI/AJ performance of the TBFH-CSS technique when the follow jamming attack exist and compared with the performance of the conventional FH-CSS technique. From the analysis, we can see the proposed TBFH-CSS technique has better LPI/AJ performance than conventional technique.

• Asian-Australasian Journal of Animal Sciences
• /
• 제21권6호
• /
• pp.776-783
• /
• 2008

In this study, we investigated the genetic diversity and phylogenetic relationship of six duck populations by employing the genetic polymorphisms of 20 microsatellites. The parameters used in this study included number of alleles, average effective numbers of alleles (E) and average rates of heterozygosity of each population. The results showed that all the microsatellite loci were highly polymorphic except that the locus AJ515896 in Muscovy duck was 0. The average PIC (0.762), average h (0.7843) and average E (5.261) of the six duck populations were all high, indicating that the gene polymorphisms and genetic diversity were high. The test of Hardy-Weinberg equilibrium showed that the six populations in this study were all in Hardy-Weinberg disequilibrium. The F-statistic analysis results showed the range of FST was from 0.0205 (AJ515895) to 0.2558 (AJ515896). The mean FST was 0.0936. Phylogenetic study revealed that Peking duck (Z1 and Z4), Shaoxing duck, Cherry Valley duck and Aobaixing duck were clustered in one group, while the Muscovy duck was clustered in one group alone. The phylogenetic relationships among different populations were in accordance with their breeding history and distribution. Our data suggested that the 20 microsatellite loci were effective markers for analysis of genetic relationships among duck populations.

• Journal of the Korea Institute of Military Science and Technology
• /
• 제21권1호
• /
• pp.115-123
• /
• 2018

In this paper, we consider the applicability of time-hopping(TH) systems for anti-jamming(AJ) communication. We first briefly summarize fundamentals of TH systems and several common jamming scenarios that have been considered in the literature. We then analyze the AJ performance of TH systems under those common jamming environments. From our simulation results, we reveal that among narrow band, partial band, broadband, and sweep jamming, partial band and sweep jamming are the best ones from jammer perspective. For the partial band jamming case, we show that the most effective bandwidth ratio and location are 50 % and 2.5-3.5 Ghz, respectively. For the sweep jamming case, we illustrate that the AJ performance of the TH system is enhanced when the sweep duration approaches to the bit duration. In addition, we pointed out that the most efficient jamming bandwidth ratio is 1/2. Finally, our results show that the TH-BPSK system greatly outperforms the TH-PPM counterpart.

• Journal of Microbiology and Biotechnology
• /
• 제13권2호
• /
• pp.175-181
• /
• 2003

The production of a carotenoid astaxanthin, a growth-associated principal pigment, is limited in a batch cultivation, because a high glucose concentration severely inhibits the cell growth and also influences the carotenoid production. Therefore, a fermentation strategy including effective chemicals for the high-level production of cells and astaxanthin by a mutant strain Phaffia rhodozyma AJ-6-1 was developed in a fed-batch culture. First, a production medium for maximizing the cell and astaxanthin yields was formulated and optimized. Using this optimized medium, the highest cell and astaxanthin concentrations obtained were about 38.25 g/1 and 34.77 mg/1, respectively. In addition, an attempt was made to increase the amount of astaxanthin using effective chemicals such as ethanol and acetic acid, which are known at an inducer and/or precursor of carotenoid synthesis. When either 10g/1 ethanol or 5 g/1 acetic acid was added to investigate the resulting astaxanthin content, a relatively high astaxanthin concentration or 45.62 mg/l and 43.87 mg/1, respectively, was obtained, and the cell concentrations also increased slightly under these conditions. Therefore, these results imply that a fed-batch culture of the mutant strain P. rhodozyma AJ-6-1 could be effectively employed in the commercial production of astaxanthin, although the factors affecting the productivity remain to be elucidated.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 한국해양정보통신학회 2004년도 춘계종합학술대회
• /
• pp.247-250
• /
• 2004

Goldschmidt 알고리즘에 의한 부동소수점 1.f2의 역수는 q=NK1K2....Kn (Ki=1+Aj, j=2i)이다. 본 논문에서는 N과 A 값을 1.f2의 값에 따라서 선정하고 Aj의 값이 유효자리수의 반이하 값을 가지면 연산을 종료하는 개선된 Goldschmidt 부동소수점 역수 알고리즘을 제안한다. 1.f2가 1.01012보다 작으면 N=2-1.f2, A=1.f2-1로 하며, 1.01012보다 크거나 같으면 N=2-0.lf2, A=1-0.lf2로 한다. 한편 Goldschmidt 알고리즘은 곱셈을 반복해서 수행하므로 계산 오류가 누적이 된다. 이러한 누적 오류를 감안하면 배정도실수 역수에서는 2-57, 단정도실수 역수에서는 2-28의 유효자리수까지 연산해야 한다. 따라서 Aj가 배정도실수 역수에서는 2-29, 단정도실수 역수에서는 2-14 보다 작아지면 연산을 종료한다. 본 논문에서 제안한 개선한 Goldschmidt 역수 알고리즘은 N=2-0.1f2, A=1-0.lf2로 계산하는 종래 알고리즘과 비교하여 곱셈 연산 회수가 배정도실수 역수는 22%, 단정도실수 역수는 29% 감소하였다. 본 논문의 연구 결과는 테이블을 사용하는 Goldschmidt 역수 알고리즘에 적용해서 연산 시간을 줄일 수 있다.

• Journal of Life Science
• /
• 제22권5호
• /
• pp.627-633
• /
• 2012

$Microbulbifer$ sp. AJ-3 was used to acquire the degrading products from $Capsosiphon$ $fulvescens$ (DPCF), which were investigated to determine its physiological activities. A crude enzyme extract from $Microbulbifer$ sp. AJ-3 hydrolyzes polysaccharide substrates such as agar, agarose, alginic acid, fucoidan, laminaran, starch, and chitin. Among them, agarose, laminaran, and alginic acid showed higher activities, especially alginic acid. The antioxidant activity of DPCF was measured by using 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and superoxide dismutase (SOD)-like activities and were about 32% and 93% at 2 mg/ml, respectively. In addition, the nitrite-scavenging activity of DPCF was about 82%, 53%, and 12% at pH levels of 1.2, 3.0, and 6.0, respectively. To determine the influence of DPCF on alcohol metabolism, the generating activity of reduced-nicotinamide adenine dinucleotide (NADH) by alcohol dehydrogenase (ADH) was measured. The facilitating rate of ADH activity by DPCF was 130% at 2 mg/ml. The tyrosinase inhibitory activity of DPCF was slightly increased in a dose-dependent manner and was about 28% at 2 mg/ml. These results indicated that the enzymatic products from DPCF have a strong antioxidant, nitrite scavenging, and alcohol metabolizing activity.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
• /
• pp.301-304
• /
• 2000

Fed-batch culture was designed to increase cell concentration and astaxanthin content by mutant AJ-6 of Phaffia rhodozyma. Fed-batch culture was performed in the continuous feeding with manual adjustment of flow rate to control glucose concentration. When the final glucose concentration was 100 g/L, the cell and astaxanthin were 38.3 g/L, 34.8 mg/L, respectively. Addition of ethanol(10 g/L), when glucose was depleted, the cell and astaxanthin concentration were 37.2 g/L and 45.6, respectively, 5 g/L of acetic acid supplied, 40.6 g/L, 43.9 mg/L were obtained. Ethanol and acetic acid enhanced the astaxanthin content act as precursor of carotenoid synthesis.

• Bulletin of the Korean Mathematical Society
• /
• 제53권5호
• /
• pp.1385-1394
• /
• 2016

Let (R, m) be a Noetherian local ring, I, J two ideals of R, and A an Artinian R-module. Let $k{\geq}0$ be an integer and $r=Width_{>k}(I,A)$ the supremum of lengths of A-cosequences in dimension > k in I defined by Nhan-Hoang [9]. It is first shown that for each $t{\leq}r$ and each sequence $x_1,{\cdots},x_t$ which is an A-cosequence in dimension > k, the set $$\Large(\bigcup^{t}_{i=0}Att_R(0:_A(x_1^{n_1},{\ldots},x_i^{n_i})))_{{\geq}k}$$ is independent of the choice of $n_1,{\ldots},n_t$. Let r be the eventual value of $Width_{>k}(0:_AJ^n)$. Then our second result says that for each $t{\leq}r$ the set $\large(\bigcup\limits_{i=0}^{t}Att_R(Tor_i^R(R/I,\;(0:_AJ^n))))_{{\geq}k}$ is stable for large n.