• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.1
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• pp.15-22
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• 1995

To study ecological properties of Vibrio cholerae non-Ol and Vibrio mimicus which have been described as new food poisoning bacteria recently, the influence of factors such as temperature, salinity, pH and chemical oxygen demand (COD) on detection rate and density of these bacteria were evaluated. Fifty four seawater samples and 49 bottom deposit samples from estuary of Kum river from March 26th, 1993 to February 22nd, 1994 were used for this study. The detection rate of V cholerae non-O1 were $16.7\%$ for seawater and $10.2\%$ for bottom deposit, respertively. The total detertion rate of V. cholerae non-O1 $(11.7\%)$ was a little higher than V mimicus $(10.7\%)$. Both V choierae non-O1 and V. mimicus were mainly detected in estuary water of which showed temperature $24^{\circ}C$ above and salinity $10\%o$ below. These bacteria were also detected in bottom deposit on January when the water temperature was $3.5^{\circ}C$. From these results, we supposed that temperature, salinity and organic material were important factors to growth of V. cholerae non-O1 and V. mimicus. V cholerae non-O1 might be grown better than V. mimicus under the fluctuating aquatic environmental condition such as salinity.

• Bulletin of the Korean Mathematical Society
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• v.52 no.5
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• pp.1467-1480
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• 2015

Generalized Fibonacci and Lucas sequences ($U_n$) and ($V_n$) are defined by the recurrence relations $U_{n+1}=PU_n+QU_{n-1}$ and $V_{n+1}=PV_n+QV_{n-1}$, $n{\geq}1$, with initial conditions $U_0=0$, $U_1=1$ and $V_0=2$, $V_1=P$. This paper deals with Fibonacci and Lucas numbers of the form $U_n$(P, Q) and $V_n$(P, Q) with the special consideration that $P{\geq}3$ is odd and Q = -1. Under these consideration, we solve the equations $V_n=5kx^2$, $V_n=7kx^2$, $V_n=5kx^2{\pm}1$, and $V_n=7kx^2{\pm}1$ when $k{\mid}P$ with k > 1. Moreover, we solve the equations $V_n=5x^2{\pm}1$ and $V_n=7x^2{\pm}1$.

• Journal of Plant Biology
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• v.1 no.1
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• pp.11-16
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• 1958

한국산 Genus Vespula THOMSON 으로는 다음 6종이 알려지고 있다. Vespula austpiaca PANZER 삼성말벌 V. germanica flevicets SMITH 해첨배기말벌 V. media RETZIUS 좀말벌 V. koieensis YADOSZKOWSKI 참땅벌 V. rufa L. var. schrenckii RADOSZAKOWSKI 슈렝크말벌 V. vulgaris L. var. Lewisii CAMERON 땅벌 상기종중에서 V. austriaca, V. rufa, V. vulgaris의 종간은 각지에서 채집된 기록이 있으나 나머지 것은 한국에 산한다고만 되어있다. 채집된 상기 3종은 형태초적으로는 거의 비슷하고 반문 만을 달리하니 그 반문의 변이를 조사하는 것은 중대한 의의를 가진다. 필자는 서울 근교우이동에서 밤을 이용하여 8개의 벌집속 벌을 모조리 채집하여 그 중 2 벌집의 개체만에 관하여 그 변이를 조사한 결과를 제1보로 여기에 발표한다. 한 벌집 속 개체수는 726과 661 이었고 다라서 총개체수 1337 마리를 조사한 결과 상당히 심히 문반변이가 잇음을 알었고 더우기 V. austriaca, V. rufa, V. koreensis 와 V. vulgaris 간의 반문차는 동일종내의 변이에 불과함을 알게 되었다. 따라서, V. austriaca, V. rufa, V. koreensis는 V. vulgaris 의 synonym 임을 밝히는 바이다. 본연구에 있어서 귀중한 교\ulcorner을 빌려주신 고대이과부장 조복의교수와 재료의 채집과 조사에 협력해준 고대생물학과생 김원임, 이경\ulcorner, 이병준, 이동\ulcorner \ulcorner군에게 감사를 표하는 바이다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.2
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• pp.386-393
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• 2004

In order to maintain load balancing in distributed systems in a decentralized manner, every node should obtain workload information from all the nodes on the network. It requires $Ο({v^2})$ traffic overheads, where v is the number of nodes. This paper presents a new synchronous dynamic distributed load balancing algorithm for a ( v,k+1,1)-configured network topology, which is a kind of 2k regular graph, based on symmetric balanced incomplete block design, where v equals ${k^2}+k+1$. Our algorithm needs only Ο(v√v) message overheads and each node receives workload information from all the nodes without redundancy. And load balancing in this algorithm is maintained so that every link has same amount of traffic by √v for transferring workload information.

• Resources Recycling
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• v.24 no.1
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• pp.21-27
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• 2015

The present study describes the process of producing low oxygen content alloy powder from Ti-6Al-4V and Ti-8Al-1Mo-1V (AMS 4972) alloy scraps using hydrogenation-dehydrogenation (HDH) and deoxidation in solid state (DOSS) processes. Each prepared powder was deoxidized with Ca contact and non-contact method to compare the deoxidation capability. It is known that the non-contact deoxidation method, using Ca vapor above the melting temperature $T_m$ of Ca, has greater deoxidation capability. However, Oxygen contents in Ti-6Al-4V and Ti-8Al-1Mo-1V powder after non-contact deoxidation method were higher than those after contact deoxidation method. Therefore, we investigate the effect of Al - the richest alloy element in theses Ti based metals - on the deoxidation processes.

• Journal of Food Hygiene and Safety
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• v.13 no.2
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• pp.149-154
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• 1998

The authors attempted utilization of fatty acid composition of vibrios as a tool for identification of the strains. Fatty acid of 49 strains of Vibrio cholerae non-O1, V. cholerae O1, V mimicus, V vulinificus and V parahaemolyticus was analyzed by gas-liquid chromatography column. According to the statistical analysis of the fatty acid data, the relationship between the Vibrio species and serotypes of the strains was discussed. Forty one kinds of fatty acid were detected from the tested strains and 35 kinds of fatty acids among the detected fatty acids were significant factors to identify the vibrios. The predominant fatty acids were 16:0, 16:1 cis 9, 18:1 trans 9/6/cis 11 and 15:0 iso 2OH/16:1 cis 9 as above about 20% in total. Fatty acid compositions of the Vibrio species were an important factor in identifying their subspecies either predominant fatty acids or minor ones. According to the analysed results by a conventional statistical processing method (UPGMA) and prepared dendrogram, V cholerae non-01 had more closer relationship with V. mimicus compared with V. cholerae 01. Moreover, the distribution of hydroxy acid was a significant factor for identifying V cholerae subspecies. Comprising all the 10 serotypes detected from V. cholerae non-01 examined such as O2, O5, O8, O10, O14, O27, O37, O39, O45 and O69, we could group them into seven subspecies by cluster analysis with the similarity value of fatty acid composition as above 92%. It means that there is a significant relationship between serotypes and fatty acid composition of V. cholerae. These results indicated that numerical analysis of fatty acid composition data of V cholerae non-01 could classifY them into subspecies, and also which may provide a useful epidemiologic information or a basis for further analysis such as PCR and DNA probe analysis.

• Bulletin of the Korean Mathematical Society
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• v.55 no.5
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• pp.1441-1462
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• 2018

In this paper, we investigate the fractional p&q-Kirchhoff type system $$\{M_1([u]^p_{s,p})(-{\Delta})^s_pu+V_1(x){\mid}u{\mid}^{p-2}u\\{\hfill{10}}={\ell}k^{-1}F_u(x,\;u,\;v)+{\lambda}{\alpha}(x){\mid}u{\mid}^{m-2}u,\;x{\in}{\Omega}\\M_2([u]^q_{s,q})(-{\Delta})^s_qv+V_2(x){\mid}v{\mid}^{q-2}v\\{\hfill{10}}={\ell}k^{-1}F_v(x,u,v)+{\mu}{\alpha}(x){\mid}v{\mid}^{m-2}v,\;x{\in}{\Omega},\\u=v=0,\;x{\in}{\partial}{\Omega},$$ where ${\Omega}{\subset}{\mathbb{R}}^N$ is an unbounded domain with smooth boundary ${\partial}{\Omega}$, and $0<s<1<p{\leq}q$ and sq < N, ${\lambda},{\mu}>0$, $1<m{\leq}k<p^*_s$, ${\ell}{\in}R$, while $[u]^t_{s,t}$ denotes the Gagliardo semi-norm given in (1.2) below. $V_1(x)$, $V_2(x)$, $a(x):{\mathbb{R}}^N{\rightarrow}(0,\;{\infty})$ are three positive weights, $M_1$, $M_2$ are continuous and positive functions in ${\mathbb{R}}^+$. Using variational methods, we prove existence of infinitely many high-energy solutions for the above system.

• Journal of the Korean Electrochemical Society
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• v.14 no.4
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• pp.214-218
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• 2011

The electrochemical characteristics and performance of redox flow battery using the soluble lead has been evaluated. Cyclic voltammetry was performed on the materials to evaluate deposition and dissolution of lead and lead dioxide. In the negative region, a reduction peak is not observed, and on the reverse scan, on-set voltage is observed at -0.47 V(vs SCE). In the positive region, the distinct peak is observed on the forward and reverse scan. The charge/discharge experiments were carried out graphite electrode in the beaker cell. The charging(deposition) of lead occurs at around 0.5 V(vs SCE) and discharging(dissolution) of lead occur at around 0.25 V(vs SCE). The potential difference is about 0.25 V. The charging(deposition) of dioxide lead is at 1.77 V(vs SCE) and discharging(dissolution) is at around 0.95 V(vs SCE) during first cycle. On subsequent cycles, the charging of dioxide lead starts at below 1.5 V(vs SCE), after a period the voltage increase to 1.7 V(vs SCE). The voltage of discharging is stable at around 1.0 V(vs SCE).

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.66.1-66.1
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• 2014

Radiative transfer programs to simulate the 3-micron auroral $CH_4$ emissions of Jupiter have been developed. The formalism of the radiative transfer calculations including the thermal, fluorescent, and auroral emissions of the $CH_4$ bands for an atmospheric layer having an optical depth of ${\tau}_v$ is given by: ${\mu}dI_v/d{\tau}_v=I_v-{\varpi}_v{^*}J_v(1-{\varpi}_v{^*})B_v-{\varpi}{^*}F_{ov}{e}{x}{p}(-{\tau}_v/{\mu}_o)4{\pi}-hv{\varpi}{^*}V/4{\pi}$ where ${\varpi}_v{^*}$ is the single scattering albedo of $CH_4$ consisting of Einstein A coefficient and collisional deexcitation rate. Other terms are usual radiative transfer parameters appearing in textbooks including the terms for scattered ${\varpi}_v{^*}J_v$, thermal $(1-{\varpi}_v{^*})B_v$, and attenuated solar radiations $F_{ov}$ at the certain atmospheric layer. For auroral excitations, we include V, which is the number of excited states per $cm^3$ persec by auroral particle bombardments. We apply this formalism to the high-resolution spectra of the auroral regions observed with GNIRS/Gemini North, and will present preliminary results for the 3 micron auroral processes of Jupiter.

• Applied Biological Chemistry
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• v.40 no.2
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• pp.107-111
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• 1997

To recover protopectinase (PPase) secreted from Bacillus subtilis IFO 12113, culture filtrate of the microorganism was treated with acetone, methanol, and ethanol, respectively. In the case of treatment with acetone at a ratio of 1: 1 (culture filtrate: acetone, v/v), PPase was purified 1.7-fold with 59.2% recovery The recovery of PPase was increased by increasing the acetone concentration. PPase was purified 4-fold with 100% recovery when the culture filtrate was precipitated with methanol at a ratio of 1 : 2 (culture filtrate: methanol, v/v). However, recovery of PPase was decreased by increasing the methanol concentration. PPase was purified 13.5-fold resulting in 68% recovery by the addition of ethanol with the final ratio 1 : 1(culture filtrate: ethanol, v/v) to the supernatant, which was obtained after precipitation of the culture filtrate with ethanol at a ratio of 1 : 0.5. These results show that methanol treatment is better than other organic solvent treatments for the simple recovery of PPase, whereas fractionated treatment of ethanol can recover PPase with higher purification fold.