• 한국인터넷방송통신학회논문지
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• 제14권6호
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• pp.295-301
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• 2014

데이터를 정렬하는 방법들 중 O(n log n)보다 빠른 방법은 알려져 있지 않고 있으며, 가장 빠른 방법으로 퀵정렬이 있다. n개의 데이터에 대해 퀵정렬은 최적의 경우 O(n log n), 최악의 경우 $O(n^2)$ 수행 복잡도를 갖고 있다. 본 논문에서는 퀵정렬보다 빠르게 정렬하는 방법으로, 분할된 리스트의 첫 번째 L=a[s], 마지막 H=a[e]과 중간 $M=[{\lfloor}(s+e)/2{\rfloor}]$에 대해 P=(L+M+H)/3의 3-점 평균을 피벗값으로 결정하는 방법을 제안하였다. 실험 결과 제안된 3-점 평균 피벗 퀵정렬은 최적, 평균, 최악 모두 수행 복잡도가 O(n log n)으로 퀵정렬의 $O(n^2)$ 정렬 시간을 단축시킬 수 있었다.

• 대한화학회지
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• 제51권6호
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• pp.499-505
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• 2007

세자리 비스(이미노)알릴 (N,C,N-집게발) 리간드를 가진 단핵 Ni(II) 착물을 발표하고자 한다. 새로운 착물(2,6-(ArN=CH)2C6H3)NiBr (Ar=2,6-dimethylphenyl (1), 2,6-diisopropylphenyl (2))은 산화성 첨가반응에 의해 Ni(COD)2 (COD=1,5-cyclooctadiene)와 1,3-(ArN=CH)2C6H3Br (bis(N-Ar)-2-bromoisophthalaldimine: Ar=Ph-2,6-Me2, Ph-2,6-iPr2) 으로부터 높은 수율로 합성하였다. 리간드와 니켈 착물에 대한 개선된 합성경로에 대하여 설명하고자 한다. 니켈(II) 착물 1, 2는 적외선 분광학, 수소-핵자기공명, 그리고 원소분석에 의해 구조를 밝혔다. 합성한 니켈 착물을 촉매로 사용하여 에틸렌 중합반응을 시도하였으나 목적하는 에틸렌고분자는 얻어지지 않고 소량의 올리고머가 형성되었다. 본 연구에서 합성한 니켈 착물이 에틸렌고분자 촉매반응에 활성을 보이지 않는 이유는 아마도 집게발 착물의 높은 경직성과 리간드의 비치환성 때문에 반응에 필요한 적합한 조건을 제공하지 못 했다고 사료된다.

• 대한수학회논문집
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• 제22권1호
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• pp.41-51
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• 2007

Let R be a ring with left identity e and suitably-restricted additive torsion, and Z(R) its center. Let H : $R{\times}R{\times}R{\rightarrow}R$ be a symmetric 3-additive mapping, and let h be the trace of H. In this paper we show that (i) if for each $x{\in}R$, $$n=<<\cdots,\;x>,\;\cdots,x>{\in}Z(R)$$ with $n\geq1$ fixed, then h is commuting on R. Moreover, h is of the form $$h(x)=\lambda_0x^3+\lambda_1(x)x^2+\lambda_2(x)x+\lambda_3(x)\;for\;all\;x{\in}R$$, where $\lambda_0\;{\in}\;Z(R)$, $\lambda_1\;:\;R{\rightarrow}R$ is an additive commuting mapping, $\lambda_2\;:\;R{\rightarrow}R$ is the commuting trace of a bi-additive mapping and the mapping $\lambda_3\;:\;R{\rightarrow}Z(R)$ is the trace of a symmetric 3-additive mapping; (ii) for each $x{\in}R$, either $n=0\;or\;<n,\;x^m>=0$ with $n\geq0,\;m\geq1$ fixed, then h = 0 on R, where denotes the product yx+xy and Z(R) is the center of R. We also present the conditions which implies commutativity in rings with identity as motivated by the above result.

• 한국환경과학회지
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• 제19권7호
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• pp.849-860
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• 2010

A new $N_3O_2$ pentadentate ligand, N,N'-Bis(2-hydroxybenzyl)-ethylenetriamine(H-BHET 3HCl) was synthesized. The hydrochloric acid salts of Br-BHET 3HCl, Cl-BHET 3HCl, $CH_3O$-BHET 3HCl and $CH_3$-BHET 3HCl containing Br-, Cl-, H-, $CH_3O-$ and $CH_3-$ groups at the para-site of the phenol group of the H-BHEP were synthesized. The structures of the ligands were confirmed by C. H. N. atomic analysis and $^1H$ NMR, $^{13}C$ NMR, UV-visible and mass spectra. The calculated stepwise protonation constants(${\logK_n}^H$) of the synthesized $N_3O_2$ ligands showed six steps of the proton dissociation. The orders of the overall protonation constants($\log{\beta}_p$) of the ligands were Br-BHET < Cl-BHET < H-BHET < $CH_3O$-BHET < $CH_3$-BHET. The orders agreed well with that of para Hammett substituent constants(${\delta}_p$). The calculated stability constants($\logK_{ML}$) between the ligands and heavy metal ions (Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Pb(II)) agreed well with the order of the overall proton dissociation constants of the ligands but they showed a reverse order in para Hammestt substituent constants(${\delta}_p$). The order of the stability constants between the heavy metal ions with the synthesized ligands were Co(II) < Ni(II) < Cu(II) > Zn(II) > Cd(II) > Pb(II).

• 한국결정학회지
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• 제12권3호
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• pp.141-144
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• 2001

Na[Ga(N₃)₄]와 PPh₃의 반응으로부터 이온성 화합물 [Ph₃P(OH)]/sup +/[N₃]/sup -/ (1)이 분리되었다. 화합물1의 구조가 분광학적 방법(¹H-NMR, /sup 13/C{¹H-NMR, IR) 및 X-ray 회절법으로 규명되었다. 화합물1의 결정학 자료 : 사방정계 공간군 P2₁2₁2₁, a = 10.491(4)Å, b=11.603(5)Å, c=13.149(5)Å, Z=4, R(wR₂)=0.0547(0.0978).

• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2517-2522
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• 2012

New polynuclear poly(hexaaza macrocyclic) copper(II) complexes $[1](ClO_4)_{2n}{\cdot}(H_2O)_{2n}$, $[2](ClO_4)_{2n}{\cdot}(H_2O)_{2n}$, and $[3](ClO_4)_{2n}{\cdot}(H_2O)_{2n}$ have been prepared by the one-pot reaction of formaldehyde with ethylenediamine and 1,2-bis(2-aminoethoxy)ethane, 1,3-diaminopropane, or 1,6-diaminohexane in the presence of the metal ion. The polymer complexes contain fully saturated 14-membered hexaaza macrocyclic units (1,3,6,8,10,13-hexaazacyclotetradecane) that are linked by $N-(CH_2)_2-O-(CH_2)_2-O-(CH_2)_2-N$, $N-(CH_2)_3-N$, or $N-(CH_2)_6-N$ chains. The mononuclear complex $[Cu(H_2L^5)](ClO_4)_4$ ($H_2L^5$ = a protonated form of $L^5$) bearing two $N-(CH_2)_2-O-(CH_2)_2-O-(CH_2)_2-NH_2$ pendant arms has also been prepared by the metal-directed reaction of ethylenediamine, 1,2-bis(2-aminoethoxy)ethane, and formaldehyde. The polymer complexes were characterized employing elemental analyses, FT-IR and electronic absorption spectra, molar conductance, X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and scanning electron micrograph (SEM). Electronic absorption spectra of the complexes show that each macrocyclic unit of them has square-planar coordination geometry with a 5-6-5-6 chelate ring sequence. The polymer complexes as well as $[Cu(H_2L^5)]^{4+}$ are quite stable even in concentrated $HClO_4$ solutions. Synthesis and characterization of the polynuclear and mononuclear copper(II) complexes are reported.

• 한국동물위생학회지
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• 제42권3호
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• pp.135-144
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• 2019

Low pathogenic avian influenza (LPAI; H9N2) and Newcastle disease (ND) are economically important poultry diseases in Korea. In this study, we investigated pathological features and virus distribution in the lymphoid tissues of chicks experimentally infected with H9N2 and/or ND virus. Six-weeks-old SPF chickens were divided into 4 groups, Control (C), H9N2 (E1), NDV (E2), and H9N2+NDV (E3). E1 group was challenged with 0.1 ml A/Kr/Ck/01310/01 (H9N2) $10^{5.6}$ $EID_{50}$ intranasally, E2 group was challenged with 0.5 ml KJW (NDV) $10^{5.0}{\sim}10^{6.0}$ $ELD_{50}$ intramuscularly, and E3 group was challenged with H9N2, followed 7 days later by NDV. In histopathological examination, E1 group showed depletion and necrosis in bursa of Fabricius, thymus, cecal tonsil, and spleen, whereas E2 and E3 groups were noted severe lymphocyte depletion and necrosis with destruction of lymphoid organs structures. In TUNEL assay, apoptotic bodies were detected in lymphoid organs of all experimental groups, which was most severe in E3 group. H9N2 and ND viruses were predominantly detected in cecal tonsil of E1, E2, and E3 groups by PCR and immunohistochemistry (ICH). In conclusion, co-infection of H9N2 with NDV caused severe pathologic lesions and apoptosis in lymphoid tissues compared to single infections.

• 약학회지
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• 제26권1호
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• pp.9-23
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• 1982

The structure of 1-butyl-3-sulfanyl urea, ($C_{11}H_{17}N_{3}O_{3}S$) carbutamide has been determined from 575 significant independent reflections collected on an automated four-circle diffractometer. The crystals are orthorhomic, space group, $P2_{1}2_{1}2_{1}$, Z=4, with unit cell dimensions a=9.257 (2), b=9.928 (2), c=15.287 (3)${\AA}$. The structure was solved by the direct methods and refined by least-squares procedure to a final R value of 0.062. Features of the structure include layers of molecules joined by N-H....O hydrogen bond distances ranging from 2.745 to 3.100${\AA}$ involved in a bifurcated hydrogen bond across two fold screw along a and b axes. The atoms forming the urea system are essentially planar.

• 대한화학회지
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• 제55권2호
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• pp.183-188
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• 2011

Ni$(C_6H_{4-n}F_n)(CO)_2$ ($C_6H_4$=benzyne, n=1-4) 착물의 전자구조 및 성질을 혼성 밀도 함수 B3LYP 이론을 이용하여 조사하였다. Benzyne 고리에 대한 방향족 성질과 벤젠핵과 무관한 화학적이동(NICS)을 분석하였다. 일-, 이- 및 삼-플루오르화 착물 중에서 3-F, 3, 6-F, 및 4-H는 각기 가장 안정한 이성질체였다. 고리 중심 상단의 여러 점에서 계산한 NICS 수치는 이들 착물의 상대 에너지에 의해 구한 값들과 일치하였다. 분자-내-원자(AIM) 분석에서 얻어진 Ni-C 결합거리는 모든 화학종에 대한 고리 임계점의 전자밀도(${\rho}_{rcp}$)와 좋은 상관성을 보였다.

• Bulletin of the Korean Chemical Society
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• 제32권3호
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• pp.894-898
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• 2011

The first example of lead compound from $Pb(NO_3)_2$ and $H_3L$ N-heterocyclic ligand $(H_3L\;=\;(HO_2C)_2(C_3N_2)(C_3H_7)CH_2(C_6H_4)(C_6H_3)CO_2H)$, $[Pb_4(L')_4]{\cdot}5H_2O$ 1 (L' = OOC$(C_3H_7)(C_3N_2)CH_2(C_6H_4)(C_6H_3)COO)$, has been obtained under hydrothermal condition by decarboxylation, and characterized by elemental analysis, IR, TGDTA, and single-crystal X-ray diffraction. Compound 1 possesses a rare two-dimensional upper-lower offset terrace-like layer structure. In 1, crystallographic distinct Pb(II) ion adopts five-coordination geometry, and two lattice water molecules occupy the voids between 2-D layers. Results of solid state fluorescence measurement indicate that the emission band 458 nm may be assigned to $\pi^*-n$ and $\pi^*-\pi$ electronic transitions within the aromatic systems of the ligand L', however, the emission bands centred at 555 nm, 600 nm and 719 nm may be derived from phosphorescent emission ($\lambda_{excitation}$ = 390 nm).