• Journal of the Korean Chemical Society
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• v.55 no.2
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• pp.230-234
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• 2011

The present study describes the synthesis of 4,5-dihydro-6-(4-methoxy-3-methylphenyl)-3(2H)-pyridazinone derivatives. The synthesis of the first target compound, 4,5-dihydro-6-(4-methoxy-3-methylphenyl)-3(2H)-pyridazinone (1), was achieved by Friedel-Crafts acylation of o-cresyl methyl ether with succinic anhydride and subsequent cyclization of the intermediary g-keto acid with hydrazine hydrate. Condensation of compound 1 with aromatic aldehydes in the presence of sodium ethoxide affords the corresponding 4-substituted benzyl pyridazinones (3a-d). The dihydropyridazinone 1 underwent dehydrogenation upon treatment with bromine/acetic acid mixture to give (4). Pyridazine (5) has been synthesized upon the reaction of pyridazinone (1) with 1,3-diphenyl-2-propen-1-one under the Michael addition reaction. N-dialkylaminomethyl derivatives 6a-b have been obtained from the reaction of pyridazinone 1 with formaldehyde and secondary amine, whereas reaction of 1 with formaldehyde gives N-hydroxymethyl derivative (7). This study also includes the synthesis of the 3-chloropyridazine derivative 8 in excellent yield by heating pyridazinone 3b in phosphorus oxychloride. The behaviour of the chloro derivative toward sodium azide, benzyl amine and anthranilic acid was also studied. The proposed structures of the products were confirmed by elemental analysis, spectral data and chemical evidence.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.23 no.3
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• pp.39-47
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• 1997

Retinol as well as RA is well known to have many beneficial effects on aged skin. But the skin irritation potential and unstable condition of the products containing them have been some problems in their cosmetic uses. So, retinol containing gel product was developed for less skin irritancy and more stability in cosmetic products. To examine the clinical effects of retinlo containing product, we used cilnicla non-invasive assessment techniques on 40 volunteers for 6 months maintaining double-blind test conditions. According to our results, the use of retinol containing product improved skin color and hydration level slightly. But there was no statistical differences. There was no erythema reaction compared to the use of RA. Especially, the skin elasticity increased above 20% and skin wrinkles of crows' feet region decreased more than 10%. Besides the instrumental analysis, a large majority of volnteers felt that their skin were improved in the case of wrunkles, elasticity, hydration and color.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.6
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• pp.30-40
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• 1995

Optically accessible D. I. diesel engine with a rectangular combustion chamber was constructed to visualize the behaviors of sprays and flames in the combustion camber with the close conditions of pressure and temperature in an actual engine. The behaviors of sprays and flames in the combustion chamber as the operating conditions of this engine were photographed with high speed camera by Diffused Background Illumination Method. With photographs taken by this method, behavior of spray droplets injected into the combustion chamber, ignition points, and flame propagation were observed and analyzed at a time-and space-dependent fashion.

• ETRI Journal
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• v.28 no.5
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• pp.574-582
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• 2006

In this paper, a new error concealment algorithm is proposed for the H.264 standard. The algorithm consists of two processes. The first process uses a fuzzy logic method to select the size type of lost blocks. The motion vector of a lost block is calculated from the current frame, if the motion vectors of the neighboring blocks surrounding the lost block are discontinuous. Otherwise, the size type of the lost block can be determined from the preceding frame. The second process is an error concealment algorithm via a proposed adapted multiple-reference-frames selection for finding the lost motion vector. The adapted multiple-reference-frames selection is based on the motion estimation analysis of H.264 coding so that the number of searched frames can be reduced. Therefore the most accurate mode of the lost block can be determined with much less computation time in the selection of the lost motion vector. Experimental results show that the proposed algorithm achieves from 0.5 to 4.52 dB improvement when compared to the method in VM 9.0.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.3169-3171
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• 2000

Most metal structures such as gas pipelines. oil pipelines, hot water pipelines and power cables etc. are buried in underground. Normally. metal structures corrode in underground by the electrochemical reaction. Then, metal structures need to be protected against corrosion. Cathodic protection is one of useful methods to protect metal structures against corrosion. In this paper we do the design of anode shape using Boundary Element Method. So we analysis the current density of anode surface and the potential distribution in the electrolyte. Therefore we seek to maximize the anode life and the safety of metal structures.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.419-422
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• 2005

Many process parameters have an effect on the auto-body panel forming process. A well-designed blank shape causes the material to flow smoothly, reduces the punch and yields a product with uniform thickness distribution. Therefore, the determination of an initial blank shape plays the important role of saving time and cost in the auto-body panel forming process. For these reasons, some approaches to estimate the initial blank shape have been implemented in this paper, the one-step approach by using a finite element inverse method will be introduced to predict the initial blank shape the developed program is applied to auto-body panel forming.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.693-694
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• 2006

In order to develop a high temperature superconducting(HTS) coil for the fault current limiter(FCL), the over-current characteristics in YBCO coated conductor(CC) with Ni-W alloy substrate are analyzed. The HTS wire is wound by bifilar winding method for resistive current limitation and it is operated in 65K sub-cooled nitrogen. In order to analyze the resistance and the temperature characteristics of the CC wire, an analysis program is developed considering all the composition materials except the buffer layer. Using this program, the temperature rise, the resistance development and the current limitation of CC are calculated depending on the applied voltage and the stabilizer materials. According to the analysis results, under the temperature restriction of 300K, the maximum voltage per meter is determined as 40V/m if the stabilizer is $25{\mu}m$ thick stainless steel at each side. Finally, the wire length needed for the distribution level HTS FCL is estimated.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1518-1518
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• 2001

In the area of the destruction-free NIR analysis of fruit and vegetables development has not yet progressed as far as in grain and similar products. One reason for that is, that in contrast to grains, in fruit and vegetables water appears as the outstanding main-component making up typically 80% by weight of the fruit. Of the M absorption spectrum of pure water the bands at 1450, 970 and 760 nm are the first, second and third overtones respectively of O-H stretch while those at 1940 and 1190 are combination bands involving O-H stretch and O-H bend. The choice of band for spectrometry is governed by considerations of sensitivity and selectivity. The overtone bands are satisfactory for use in moisture measurements from 0 to 4 % depending on path length. Measurements in fruits and vegetables at wavelength areas that are also important for the determination of carbohydrates (sucrose, glucose, fructose) often lead to total absorption in the presence of significant water even if short path lengths are possible. In this work model systems are used containing different carbohydrates in solvents like heavy water (D$_2$O) or dimethylsulfoxide (DMSO) that do not contain O-H functional groups.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1668-1670
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• 2003

This paper deals with a development of the high precise measuring device of resistive leakage current for the deterioration and diagnosis of ZnO arresters. The resistive leakage current increasing with time leads to a thermally unstable state that may even experience a disaster. So, the resistive leakage current can be used as an indicator to discriminate whether the ZnO arrester blocks is in good state or in bad. The resistive leakage current measuring system with an analysis program operated with micro-processor using the time delay addition method was designed and fabricated. The proposed measuring systems for the resistive leakage current can effectively be used to develop the techniques of forecasting the deterioration of ZnO arresters in electric power systems.⨀ᔌ?؀㔳㤮㈻Ԁ䭃䑎䷗ᜒं6〰Ԁ䭃䑎䴀

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1980-1983
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• 2005

The characteristic of sheet metal process is the few loss of material during process, the short processing time and the excellent price and strength. The sheet metal process with above characteristic is common used in industrial field, but in order to analysis irregular field problems the reliable and economical analysis method is demanded. Finite element method is very effective method to simulate the forming processes with good prediction of the deformation behaviour. Among Finite element method, The static-implicit finite element method is applied effectively to analyze real-size auto-body panel stamping processes, which include the forming stage. In this paper, it was focussed on the drawability factors on auto-body panel stamping by AUTOFORM with using tool planing alloy to reduce law price as well as high precision from Design Optimization of ide. According to this study, the results of simulation will give engineers good information to access the Design Optimization of die.