• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2007.11a
• /
• pp.104-107
• /
• 2007

In this paper, we propose the coordination scheme in a single-manufacturer-multiple-retailer supply chain system. Traditionally, the bargaining power of the single manufacturer is superior to those of retailers. The business environment supported by the e-business scheme may give rise to new business behavior. The multitude of retailer requests the manufacturer to relax the his unilateral lot-sizing policy while they are willing to compensate more than the manufacturer's expected loss caused by abandon his superior bargaining power. The side payment aggregated by the multiple retailers is transferred to the manufacturer according to the degree of the manufacturer's relaxation from the current unilateral lot-sizing policy.

• Korean Journal of Crystallography
• /
• v.11 no.2
• /
• pp.84-88
• /
• 2000

The crystal of cholesteryl crotylcarbonate was investigated by X-ray diffraction method. Crystallographic data for the title compound: P21, a=13.510(2)Å, b=11.843(2)Å, c=19.882(2)Å, β=106.88(1)°, Z=4. Reflections were collected with an Enraf-Nonius CAD-4 diffractometer equipped with a graphite monochromator. The structure was solved by direct methods and refined by least-squares analyses. The final R value was 0.125 for 2607 reflections. The cholesterol fragment of the title compound were in good agreement with those for related cholesterol derivatives. The molecules were stacked in clearly separated layers. At the center of the layers, there were cholesteryl-cholesteryl interactions between the symmetry-related B molecules and the cholesteryl-C(17) side chain of A molecules. There were also interactions between the C(17) side chain of B molecules and the crotylcarbonate chain in the interface region between layers. The crystal structure of the title compound turned out to be isostructural with those of cholesteryl ethylcarbonate and cholesteryl propylcarbonate.

• Bulletin of the Korean Chemical Society
• /
• v.19 no.2
• /
• pp.178-183
• /
• 1998

Carbon-13 CP-MAS NMR techniques were used to investigate dynamics of new combined type liquid crystalline polymers, poly[oxy-1,4-phenyleneoxy-2-{6-(4-(4-butylphenylazo)phenoxy)hexyloxy}terephthaloyl] and poly[oxy-1,4-phenyleneoxy-2-{10-(4-(4-butylphenylazo)phenoxy)decyloxy}terephthaloyl]. Noticeable mobility change of either aromatic groups or methylene groups is not detected between 25 ℃ and 82 ℃ from 13C spinlattice relaxation time in the rotating frame (T1ρ(C)) and contact time array experiments. However, line shape analysis shows the increase of mobility of methylene carbons in poly[oxy-1,4-phenyleneoxy-2-{6-(4-(4-butylphenylazo)phenoxy)hexyloxy}terephthaloyl] at higher temperature. The dynamics of side chanis does not seem to be affected in our experimental temperature range by the length of aliphatic chain which is connecting the side chain group to the main chain.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.3
• /
• pp.828-832
• /
• 2012

We performed replica exchange molecular dynamics (REMD) simulations of the tripzip2 peptide (betahairpin) using the GB implicit and TI3P explicit solvation models. By comparing the resulting free energy surfaces of these two solvation model, we found that the GB solvation model produced a distorted free energy map, but the explicit solvation model yielded a reasonable free energy landscape with a precise location of the native structure in its global free energy minimum state. Our result showed that in particular, the GB solvation model failed to describe the tryptophan packing of trpzip2, leading to a distorted free energy landscape. When the GB solvation model is replaced with the explicit solvation model, the distortion of free energy shape disappears with the native-like structure in the lowest free energy minimum state and the experimentally observed tryptophan packing is precisely recovered. This finding indicates that the main source of this problem is due to artifact of the GB solvation model. Therefore, further efforts to refine this model are needed for better predictions of various aromatic side chain packing forms in proteins.

• Journal of the Korean Chemical Society
• /
• v.36 no.2
• /
• pp.293-300
• /
• 1992

The synthesis of a series of 7-[(Z)-2-(2-aminothiazol-4-yl)-2-oxyiminoacetamido]-3-(4,6-diamino-1-alkyl-1,3,5-triazinium-2-yl)thiomethyl-3-cephem-4-carboxylates is described. Variations of an oxyimino moiety in the 7-side chain and quaternary ammonium moiety in the 3-side chain were examined and structure-activity relationship was studied. The 4,6-diamino-1-methyl-1,3,5-triazinium-2-yl derivative of the 7-$\alpha$-methoxyimino series of cephalospoins, particularly 7-[(Z)-2-(2-aminothiazol-4-yl)-2-(methoxyimino)acetamido]-3-(4,6-diamino-1-methyl-1,3,5-triazinium-2-yl)thiomethyl-3-cephem-4-carboxylate(C-1), exhibited broad antibacterial activity against Gram-positive and Gram-negative bacteria including Pseudomonas aeruginosa.

• Proceedings of the Korean Fiber Society Conference
• /
• 1997.10a
• /
• pp.32-35
• /
• 1997

Aggregation states ans electro-optic properties of a binary mixture by mixing a side chain type liquid crystalline polymer(LCP) and a low molecular weight liquid crystal(LMLC) have been studied. Side chain liquid crystalline polysiloxanes were synthesized from allyl bromide, p-hydroxy benzoic acid, p-cyanophenol, p-methoxyphenol and polysiloxanes. Low molecular weight liquid crystals were synthesized from allyl bromide, p-hydroxy benzoic acid and 4-cyano 4'-hydroxy biphenyl. And then, their properties were compared with blended liquid crystals. The thermal properties of the blended liquid crystals were evaluated using differential scanning calorimetry. The phase behavior of blended sample with temperature were also observed polarized microscope with hot stage. Thus, it seemed to us that a study of LC polysiloxanes with LMLC would be useful, especially in view of the fact that, systematic investigations have been carried out on the effects of changes in LCP/LMLC binary system on the properties of this relatively new type of liquid crystal.

• Korean Journal of Optics and Photonics
• /
• v.9 no.4
• /
• pp.215-220
• /
• 1998

We proposed an in situ measurement set-up and technique to measure the various electro-optic(E-O) properties of the E-O polymer. Using the proposed measurement set-up, the electro-optic effect and birefringence of unpoled side-chain E-O polymer induced by the strong dc and ac electric field were observed. The dependence of the E-O coefficients on the various poling conditions were measured with real time. To evaluate the thermal stability of the poled polymer the relaxation of the E-O effect was measured and the result was compared with well known polymer materials. The proposed measurement reduces the number of experimental steps and saves measurement time.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.5
• /
• pp.1443-1454
• /
• 2011

Methods to prepare novel second-order nonlinear optical (2O-NLO) materials composed of all-silica zeolite (silicalite-1) and a series of 2O-NLO molecules having high second order hyperpolarizability constants (${\beta}$ values) are reviewed. These methods include the development of novel methods to incorporate a series of hemicyanine (HC) molecules into the channels of silicaite-1 films in uniform orientations. The first method is to incorporate HC molecules tethered with long alkyl chains (octadecyl or longer) into the silicalite-1 channels with the long alkyl chain side first through the hydrophobic-hydrophobic interaction between the long alky chains and the silicalite-1 channels. The second method is to incorporate the HC molecule tethered with a medium length alkyl chain (nonyl) into the silicalite-1 channels with the medium length alkyl chain side first through hydrophobic-hydrophobic interaction between the medium length alky chain in the photoexcited state and the silicalite-1 channels. The third method is to incorporate the HC molecule tethered with propionic acid into the silicalite-1 channels with the propionic acid side last mediated by a tetrabultylammonium cation ion-paired to the propionate unit. A method to prepare a novel third-order nonlinear optical (3O-NLO) material composed of zeolite-Y and PbS or PbSe quantum dots is also reviewed. This Account thus describes a promising new direction to which the search for highly sensitive 2O-NLO and 3O-NLO materials has to be conducted and a new direction to which zeolite research and applications have to be expanded.

• Polymer Science and Technology
• /
• v.2 no.6
• /
• pp.424-437
• /
• 1991

• Bulletin of the Korean Chemical Society
• /
• v.21 no.10
• /
• pp.1000-1004
• /
• 2000