• 충청수학회지
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• 제20권1호
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• pp.65-70
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• 2007

We study the existence of nontrivial solutions of the Gradient type Dirichlet boundary value problem for elliptic systems of the form $-{\Delta}U(x)={\nabla}F(x,U(x)),x{\in}{\Omega}$, where ${\Omega}{\subset}R^N(N{\geq}1)$ is a bounded regular domain and U = (u, v) : ${\Omega}{\rightarrow}R^2$. To study the system we use the liking theorem on product space.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제4권3호
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• pp.337-340
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• 2004

The clustering problem can be formulated as the problem to find the number of clusters and a partition matrix from a given data set using the iterative or non-iterative algorithms. The author proposes a nearest neighbor and validity-based clustering algorithm where each data point in the data set is linked with the nearest neighbor data point to form initial clusters and then a cluster in the initial clusters is linked with the nearest neighbor cluster to form a new cluster. The linking between clusters is continued until no more linking is possible. An optimal set of clusters is identified by using the conventional cluster validity index. Experimental results on well-known data sets are provided to show the effectiveness of the proposed clustering algorithm.

• Membrane and Water Treatment
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• 제6권3호
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• pp.173-187
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• 2015

The goal of present work is the preparation of a novel positively charged nanofiltration (NF) membrane and its development for the cation removal of aqueous solutions. This NF membrane was fabricated by the surface modification of polysulfone (PSf) ultrafiltration support. The active top-layer was formed by interfacial cross-linking polymerization of poly(ethyleneimine) (PEI) with p-xylylene dichloride (XDC) and then quaternized with methyl iodide to form a perpetually positively charged layer. In order to improve the efficiency of nanofiltration membrane, the concentration of PEI, XDC and methyl iodide solutions, PEI coating and cross-linking time have been optimized. As a result, a high water flux and high $CaCl_2$ rejection (1,000 ppm) was obtained for the composite membrane with values of $18.29L/m^2.h$ and 93.62% at 4 bar and $25^{\circ}C$, respectively. The rejections of NF membrane for different salt solutions followed the order of $Na_2SO_4$ < $MgSO_4$ < NaCl < $CaCl_2$. Molecular weight of cut off (MWCO) was calculated via retaining of PEG solutions with different molecular weights that finally, it revealed the Stokes and hydrodynamic radius of 1.457 and 2.507 nm on the membrane selective layer, respectively. The most efficient positively charged nanofiltration membrane exhibited a $Ni^{2+}$ rejection of 96.26% for industrial wastewater from Shamse Hadaf Co. (Kashan, Iran).

• Archives of Pharmacal Research
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• 제24권5호
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• pp.455-465
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• 2001

The highly potent cytotoxic DNA-DNA cross-linker consists of two cyclopropa[c]pyrrolo[3,4-3]indol-4(5H)-ones insoles [(+)-CPI-I] joined by a bisamido pyrrole (abbreviated to "Pyrrole"). The Pyrrole is a synthetic analog of Bizelesin, which is currently in phase II clinical trials due to its excellent in vivo antitumor activity. The Pyrrole has 10 times more potent cytotoxicity than Bizelesin and mostly form DNA-DNA interstrand cross-links through the N3 of adenines spaced 7 bp apart. The Pyrrole requires a centrally positioned GC base pair for high cross-linking reactivity (i.e., $5^1$-T$AT_2$A*-$3^1$), while Bizelesin prefers purely AT-rich sequences (i.e., $5^1$-T$AT_4$A*-$3^1$, where /(equation omitted) represents the cross-strand adenine alkylation and A* represents an adenine alkylation) (Park et al., 1996). In this study, the high-field $^1$H-NMR and rMD studies are conducted on the 1 1-mer DNA duplex adduct of the Pyrrole where the 5′(equation omitted)TAGTTA*-3′sequence is cross-linked by the drug. A severe structural perturbation is observed in the intervening sequences of cross-linking site, while a normal B-DNA structure is maintained in the region next to the drug-modified adenines. Based upon these observations, we propose that the interplay between the bisamido pyrrole unit of the drug and central C/C base pair (hydrogen-bonding interactions) is involved in the process of cross-linking reaction, and sequence specificity is the outcome of those interactions. This study suggests a mechanism for the sequence specific cross-linking reaction of the Pyrrole, and provides a further insight to develop new DNA sequence selective and distortive cross-linking agents.

• 한국어학
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• 제48권
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• pp.333-354
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• 2010

When defining the word related to passive and causative in Korean dictionary, the meaning of headword can be explained by linking them to other related words. The link could be expressed into two forms; the one is 'passive verb causative verb of A' and the other is 'passive form causative form of A.' Whichever the dictionary takes, the important thing is that the content to which it refer should be correct. However the format of 'passive verb causative verb of A' and 'passive form causative form of A' is problematic because the definition of headword does not contain semantic information but syntactic or morphological information. Generic concept 'passive form causative form' and 'passive verb causative verb' refers to respectively morphological and syntactic level but specific concept 'A' refers to semantic level. These morphological, syntactic and semantic level can not be a same dimension so the size of their denotation can not be compared. The way of transform syntactic dimension 'passive verb causative verb' and morphological dimension 'passive form causative form' into semantic dimension is removing 'verb' and 'form' from 'passive verb causative verb' and 'passive form causative form' respectively. Therefore the expression 'passive verb causative verb of A' or 'passive form causative form of A' ought be changed into 'passive causative of A.'

• Kyungpook Mathematical Journal
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• 제48권2호
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• pp.241-254
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• 2008

We define the crosscap number of a 2-component link as the minimum of the first Betti numbers of connected, non-orientable surfaces bounding the link. We discuss some properties of the crosscap numbers of 2-component links.

• 한국빅데이터학회지
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• 제4권2호
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• pp.195-205
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• 2019

LOD(Linked Open Data)는 데이터 공개방식 중에서 가장 우수한 수준으로 평가받고 있으며, 인터넷 상에서 서로 관련있는 데이터를 표준방식으로 연결하여 하나의 거대한 데이터베이스처럼 검색할 수 있도록 한다. 글로벌 환경에서 관련있는 데이터들이 LOD 형태로 구축되는 사례가 증가하고 있으나 국내 보건의료 분야에서 LOD 형태의 데이터 공개는 아직 초보적인 수준에 머물러 있다. 본 논문에서는 한국의학연구논문 데이터와 보건의료 빅데이터 연계 플랫폼 데이터를 중심으로 국내외 관련있는 DB들을 LOD 방식으로 연계하여 서비스하는 LOD 플랫폼 구축사례를 소개한다. 각 DB의 모든 데이터를 LOD로 연계하는 것은 시간과 노력이 많이 필요하며, 기본적으로 민간보다 국가나 공공기관이 담당해야 하는 인프라성 연구이다. 본 연구에서는 각 DB의 일부만을 대상으로 하여 LOD국내외 10개 사이트를 연계하였으며, 이를 통해 사용자는 편리한 방식으로 국내외 여러 기관의 데이터를 연계하여 검색할 수 있게 된다.

• Fibers and Polymers
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• 제4권4호
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• pp.182-187
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• 2003

Low molecular weight copolymers of maleic anhydride and vinyl acetate were prepared to develop formaldehyde free cross-linking agents. Since lower molecular weight is favorable for efficient penetration of the finishing agent into the cotton fibers in the padding process, the concentration of the initiator, chain transfer agent and the monomer ratios were varied to obtain copolymers of low molecular weights. The prepared polymers were characterized by GPC, $^1{H-NMR}$, FTIR, DSC and TGA. Copolymers of molecular weights of 2 000 to 10 000 were obtained and it was found that the most efficient method of controlling the molecular weight was by varying the monomer ratios. Poly(maleic anhydride-co-vinyl acetate) did not dissolve in water, but the maleic anhydride residue hydrolyzed within a few minutes to form poly(maleic acid-co-vinyl acetate) and dissolved in water. However, the maleic acid units undergo dehydration to form anhydride groups on heating above ${160}^{\circ}C$ to some extent even in the absence of catalysts. The possibility of using the copolymers as durable press finishing agent for cotton fabric was investigated. Lower molecular weight poly(maleic anhydride-co-vinyl acetate) copolymers were more efficient in introducing crease resistance, which appears to be due to the more efficient penetration of the cross-linking agent into cotton fabrics. The wrinkle recovery angles of cotton fabrics treated with poly(maleic anhydride-co-vinyl acetate) copolymers were slightly lower than those treated with DMDHEU and were higher when higher curing temperatures or higher concentrations of copolymer were used, and when catalyst, $NaH_2$$PO_2$, was added. The strength retention of the poly(maleic anhydride-co-vinyl acetate) treated cotton fabrics was excellent.

• 한국운동역학회지
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• 제14권2호
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• pp.1-14
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• 2004

This study was intended to contribute to allowing athletes to raise a technical understanding of two motions of high difficulty such as the Swallow motion and the Nakayama motion and enhance their competitive power by analysing the kinematical factors required to link those two motions on the competitive scene on the rings for current national athletes. For this purpose, the game of the ring event was videotaped for male heavy gymnasts participating in the final elimination match of the 2004 Athens Olympic Games. This study attempted to select the performing motions of the final 1st-and 2nd-place athletes performing the linking motions from the Swallow motion and the Nakayama motion using the DLT(direct linear transformation) method. As a result, it arrived at the following conclusion : A1 properly performed the flexing and extending movements using the angular velocity of the segment and joint as the switching motion using the body at the time of linking the motion from the Swallow skill to the Nakayama skill. A2 was evaluated to perform the skill taking the form of depending on the force at the static state. Therefore, it is thought that A1 should take care of shaking at the time of using the elasticity of the body. It is thought that in case of A2 the proper use of the elasticity of the body take care of shaking at the switching motion while taking advantage of the force will contribute to his competitive power.

• 멤브레인
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• 제11권3호
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• pp.109-115
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• 2001

Polypropylene(PP)을 지지막으로 하여 in-situ 가교결합(cross-linking)방식을 이용한 pore-filled 이온교환막을 제조하였다. 다공성 PP막의 기공에 poly(vinylbenzyl chloride)(PVBCI)과 piperazine(PIP), 또는 1,4-diaminobicyclo [2,2,2]octane(DABCO)을 dimethylforamid(DMF)에 녹인 용액을 채워서 겔화시킨 후, 남아있는 chloromethyl 그룹에 trimethylamine을 이용하여 양이온인 암모니움 site를 형성시키면 pore-filled 음이온교환막이 형성된다. 이와 같은 2단계의 제조방식으로 제조된 pore-filled 분리막은 크기의 변화가 없이 안정되며, PVBCI의 농도와 가교제의 농도로써 고분자-겔의 함량(mass gain, MG)과 가교도가 간단하게 조절되는 것을 보여주었다. 특히 아주 낮은 압력(100 kPa)에서의 높은 수투과도(7.9kg/$m^2$hr, 지지막은 PP3, 73%의 MG, 10%의 가교도, PIP 가교제사용)는 연수용 분리막으로 충분히 활용될 수 있음을 보여준다.