• Journal of the Korean Chemical Society
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• v.55 no.6
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• pp.919-925
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• 2011

A new series of manganese(II), iron(III) and cobalt(III) complexes of 14-membered macrocyclic ligand, (3,6,10,13,16,19-hexaazabicyclo[6.6.6]icosane-1,8-diamine) have been prepared and characterized by elemental analyses, IR, UV-VIS, $^1H$- and $^{13}C$- NMR spectra, magnetic susceptibilities, conductivities, and ESR measurements. Molar conductance measurements in DMF solution indicate that the complexes are electrolytes. The ESR spectrum for cobalt(III) complex in $CD_3OD+10%D_2O$ after exposure to $^{60}Co-{\gamma}$-rays at 77 K using a 0.2217 M rad $h^{-1}$ vicrad source showed $g_{\perp}$ > $g_{\parallel}$ > $g_e$, indicating that, the unpaired electron site is mainly present in the $d_z2$ orbital with covalent bond character. In this case, the ligand hyperfine tensors are nearly collinear with ${\gamma}$-tensors, so there is no major tendency to bend. Therefore, little extra delocalization via the ring lobe of the $dz^2$ orbital occurs. However, the ESR spectrum in solid state after exposure to $^{60}Co-{\gamma}$-rays at 77 K showed $g_{\parallel}$ > $g_{\perp}$ > $g_e$, indicating that, the unpaired electron site is mainly present in the $d_x2_{-y}2$ ground state as the resulting spectrum contains a large number of randomly oriented molecules provided that, the principle directions of g and A tensors. Manganese (II) complex 2, $[H_{12}LMn]Cl_4.2H_2O$, showed six isotropic lines characteristic to an unpaired electron interacting with a nucleus of spin 5/2, however, iron(III) complex 3, $[H_{12}LFe]Cl_5.H_2O$, showed spectrum of a high spin $^{57}Fe$ (I=1/2), $d^5$ configuration. The geometry of these complexes was supported by elemental analyses, IR, electronic and ESR spectral studies. Complex 1 showed exploitation in reducing the amount of electron adducts formed in DNA during irradiation with low radiation products.

• Journal of the Korean Chemical Society
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• v.55 no.2
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• pp.189-198
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• 2011

In the present paper two new thiosemicarbazones i.e., 4[N-(4'-ethylbenzalidene)amino]antipyrine thiosemicarbazone (EBAAPTS) and 4[N-(2',4'-dimethylbenzalidene)amino]antipyrine thiosemicarbazone (DMBAAPTS) have been synthesized and characterized. The complexing abilities of these thiosemicarbazones i.e. EBAAPTS and DMBAAPTS towards cobalt(II) and nickel(II) salts have been explored. The reactions of the hot ethanolic solutions of cobalt(II) and nickel(II) salts with EBAAPTS and DMBAAPTS led to the formation of the novel complexes of general composition [$MX_2(L)H_2O$] (M=$Co^{2+}$ or $Ni^{2+}$; X=$Cl^-$, $Br^-$, $NO_3^-$, $NCS^-$ or $CH_3COO^-$; L=EBAAPTS or DMBAAPTS). The newly synthesized complexes have been characterized by elemental analyses, molar mass, molar conductance, magnetic susceptibility, infrared and electronic spectral studies. The molar conductance measurements of the complexes in nitrobenzene correspond to their non-electrolytic nature. All the complexes are of high-spin type. On the basis of spectral studies an octahedral geometry has been assigned for Co(II) and Ni(II) complexes of the type [$MX_2(L)H_2O$]. These complexes were screened for their antibacterial and antifungal activities on different species of pathogens, fungi and bacteria and their biopotency has been discussed.

• Journal of the Korean Chemical Society
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• v.53 no.6
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• pp.683-692
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• 2009

The synthesis of a novel series of nickel(II) complexes with new ligands derived from hydrazones of isoniazid have been reported in present work. The complexes have general compositions [$Ni(L)_2X_2$] or $[Ni(L)_3](ClO_4)_2$ {L = N-isonicotinamido-furfuraldimine (INH-FFL), N-isonicotinamido-3',4',5'-trimethoxybenzaldimine (INH-TMB) or N-isonicotinamido-cinnamalidene (INH-CIN) and X = $Cl^-$, ${NO_3}^-$, $ NCS^-$ or $CH_3COO^-$}. The ligands hydrazones behave as neutral bidentates (N and O donor) through the carbonyl oxygen and azomethine nitrogen. The new complexes with octahedral geometry have been characterized by elemental analysis, molecular weight determinations, magnetic susceptibility/moment, thermogravimetric, electrochemical and spectroscopic studies viz. infrared and electronic spectra. On the basis of conductivity measurements in nitrobenzene ($PhNO_2$) solution the [$Ni(L)_2X_2$] and $[Ni(L)_3](ClO_4)_2$ complexes have been found to be non-electrolytes and 1:2 electrolytes, respectively. Thermal properties have also been investigated, which support the geometry of the complexes. Antibacterial and antifungal properties of nickel(II) complexes and few standard drugs have also been examined and it has been observed that the complexes have moderate antibacterial activities.

• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.523-532
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• 2010

The proposed method is simple, sensitive and specific Liquid chromatography-tandem mass spectrometry (LCESI-MS/MS) method for the quantification of Entacapone (EA) in human plasma using Entacapone-d10 (EAD10) as an internal standard (IS). Chromatographic separation was performed on Zorbax SB-C18, $2.1{\times}50\;mm$, $5\;{\mu}m$ column, mobile phase composed of 10 mM Ammonium formate (pH 3.0): Acetonitrile (60:40 v/v), with a flow-rate of 0.7 mL/min, followed by Liquid-liquid extraction. EA and EAD10 were detected with proton adducts at m/z $306.1{\rightarrow}233.1$ and $316.3{\rightarrow}233.0$ in multiple reaction monitoring (MRM) positive mode respectively. The method was validated over a linear concentration range of 1.00 - 2000.00 ng/mL with correlation coefficient ($r^2$) $\geq$ 0.9993. Intra and inter-day Precision within 3.60 to 7.30 and 4.20 to 5.50% and Accuracy within 97.30 to 104.20 and 98.30 to 105.80% proved for EA. This method is successfully applied in the bioequivalence study of healthy Indian human volunteers.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.2
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• pp.63-70
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• 2014

Design sensitivity analysis and topology design optimization for a piezoelectric crystal resonator are developed. The piezoelectric crystal resonator is deformed mechanically when subjected to electric charge on the electrodes, or vice versa. The Mindlin plate theory with higher-order interpolations along thickness direction is employed for analyzing the thickness-shear vibrations of the crystal resonator. Thin electrode plates are masked on the top and bottom layers of the crystal plate in order to enforce to vibrate it or detect electric signals. Although the electrode is very thin, its weight and shape could change the performance of the resonators. Thus, the design variables are the bulk material densities corresponding to the mass of masking electrode plates. An optimization problem is formulated to find the optimal topology of electrodes, maximizing the thickness-shear contribution of strain energy at the desired motion and restricting the allowable volume and area of masking plates. The necessary design gradients for the thickness-shear frequency(eigenvalue) and the corresponding mode shape(eigenvector) are computed very efficiently and accurately using the analytical design sensitivity analysis method using the eigenvector expansion concept. Through some demonstrative numerical examples, the design sensitivity analysis method is verified to be very efficient and accurate by comparing with the finite difference method. It is also observed that the optimal electrode design yields an improved mode shape and thickness-shear energy.

• Management & Information Systems Review
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• v.15
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• pp.109-145
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• 2004

Upcoming 21st century, Management circumstance for a small and medium enterprise have been rapidly changed by Knowledge management, Informationization, Hi-technology. Changing from an era of small concept to strong concept, It will be a severe innovation period and can not survive with life as the same as the past, It is the era of best which mean only the best can survive, None of the average faculty can survive. Due to rapid proceeding of innovation of Informationization, It stimulate acceleration of technology innovation, infinity competition regardless the nation boarder, result in proceeding to Informationization. A small and medium enterprise is defined as smaller size of business than big business as point of capital, employee, output. It is concept, which usually used against concept of big business. When define a small and medium enterprise, criteria to determine a small and medium enterprise is depends on country and a category of business. However, In every country, A small and medium enterprise is getting be bigger and importance factor in whole industry. A small and medium enterprise is well developed and also well balanced with a large enterprise in the developed country. All around in the world, Interest about a small and medium enterprise is becoming higher. It is actively researching into a small and medium enterprise as the mean to create new employment, new industry, as means to from integration of a all and medium enterprise,as source of high competitive power. The status quo of rapid changing into informationization have been realized at considerable level in Korea. Information society is defined as information technology is main key to determine individuals competitiveness, which can solve effectively the side effect result from industrialization. It cleary imply that information technology is the most promising and important industry in 21st century. Therefore, We should seek to foster independent a small and medium enterprise and develop them corresponding to new concept of a small and medium enterprise in 21st century. The main frame of policy should be new economic system, which can contribute establishment of a small and medium enterprise, management innovation. It also attribute a small and medium enterprise to reveal their creative. New economic paradigm in 21st will be expanded with organization, market, technology. So far, a small and medium enterprise has been acknowledge as economic weaker and the one should be protected. However, In 21st century a small and medium enterprise will be considered as active majority or a source of creative. Development of technology to produce a small quantity with variety product and acceleration of knowledge and informationization will result in comparative merits of a small and medium enterprise. Hereby, The role and relative importance of a small and medium enterprise in our economic will getting be larger and It will be developed as the main force to activate the economic. However, Only a small and medium enterprise, which overcome difficulty with active desire and effort to improve their lot can be developed as a competitive enterprise in 21st century in considering themselves to be developed as diversity, active, independent, business by an enterprise.

• Management & Information Systems Review
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• v.31 no.3
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• pp.47-73
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• 2012

SNS allowed users to serve not only as the content and message producer but as the consumer, with development into various types of SNS platforms. Instead of a traditional media structure of media-to-many and unspecified users, it also made it possible to achieve one-to-one or one-to-many interactions, regardless of time and space, through SNS platforms. Moreover, according to development of digital communication technology, IT, media contents and communication network have been mutually connected, though they were once separate. The changes in communication environments have caused rapid disorganization and reorganization in popular culture led by specific expert groups. Such trend has a greater influence on marketing strategies of enterprises. In other words, it will lead them to mostly introduce new information technologies, based on consumer market, and to strategically participate in SNS for promotion and marketing for their products and brands. Likewise, SNS has currently appeared as the main media affecting consumers' behaviors. In consideration of the importance of SNS features, which can stimulate responses of other users, analysis of main features affecting SNS user acceptance decision is required, as well as its utilization strategies. Accordingly, this study conducted division of SNS features into openness, quickness, interactiveness and economical efficiency to derive strategies for increasing the usage frequency of SNS and ultimately maximizing the expectation effect, in addition to an empirical analysis of effects of SNS features on usefulness, easiness and pleasure perceived in SNS, and SNS user intention.

• Korean Journal of Environment and Ecology
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• v.28 no.6
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• pp.697-704
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• 2014

Mt. Hallasan in Jejudo has been well known as a habitat for both northern and southern limited butterflies and attracts the interests of many lepidopterists. In this study, the line transect method was used to monitor the community and similarity of butterflies monthly monitoring from May to September 2013, and the results were compared with the previous data. Through monitoring, 3,397 individuals in 26 species of 5 families were found in the present study. The monitored individuals belonging to 4 species (Aphantopus hyperantus, Eumenis autono, Lethe diana and Melanargia epimede) was 2,578 (75.9%), showing the prevalent species among the butterflies observed in the grassy area of the Mt. Hallasan. The butterflies inhabiting Mt. Hallasan showed higher similarity in the area where the open grassy space and the crowns of tree layer coexist than in landscape consisting of solely the tree layer or open grassy space. The habitation of butterflies by heights showed the altitudes between 1,665 to 1,700 m, located beneath the Baekrokdam (the crater) of Mt. Hallasan, possessed the most species and individuals. And it was also observed that the species that previously inhabited the subalpine zone moved to the area of higher altitudes together with the species that previously inhabited rather lower altitudes than the subalpine zone.

• Proceedings of KOSOMES biannual meeting
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• 2005.05a
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• pp.147-154
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• 2005

The ship plating is generally subjected to combined in-plane load and lateral pressure loads. In-plane loads include axial load and edge shear, which are mainly induced by overall hull girder bending and torsion of the vessel. Lateral pressure is due to water pressure and cargo. These load components are not always applied simultaneously, but more than one can normally exist and interact Hence, for more rational and safe design of ship structures, it is of crucial importance to better understand the interaction relationship of the buckling and ultimate strength for ship plating under combined loads. Actual ship plates are subjected to relatively small water pressure except for the impact load due to slamming and panting etc. The present paper describes an accurate and fast procedure for analyzing the elastic-plastic large deflection behavior up to the ultimate limit state of ship plates under combined loads. In this paper, the ultimate strength characteristics of plates under axial compressive loads and lateral pressure loads are investigated through ANSYS elastic-plastic large deflection finite element analysis with varying lateral pressure load level.

• Proceedings of KOSOMES biannual meeting
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• 2005.05a
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• pp.141-146
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• 2005

Ship have cutout inner bottom and girder and floor etc. Ship's structure is used much, and structure strength must be situated, but establish new concept when high stress interacts sometimes fatally the area. There is no big problem usually by aim of weight reduction, a person and change of freight, piping etc. Because cutout's existence grow up in this place, and, elastic buckling strength by load causes large effect in ultimate strength. Therefore, stiffened perforated plate considering buckling strength and ultimate strength is one of important design criteria which must examine when decide structural concept at initial design. Therefore, and, reasonable buckling strength about perforated stiffened plate need to ultimate strength limited design . Calculated ultimate strength varied several web height and cutout's dimension, and thickness in this investigated data. Used program(ANSYS) applied F.E.A code based on finite element method.