• Journal of KSNVE
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• v.9 no.6
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• pp.1247-1258
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• 1999

This paper presents vibration control of a CD-ROM(compact disc-read only memory) drive feeding system consisting of a new type of CD-ROM mount using an electro-rheologocal(ER) fluid. Chemically treated starch particles and silicon oil are used for EF fluid, and its field-dependent yield stresses are experimentally distilled under both the shear and the flow modes. On the basis of the yield stress, an appropriate size of ER CD-ROM mount adapted to conventional feeding system is designed and manufactured. Vibration isolation performance of the proposed mount is evaluated in the frequency domain and compared with that of conventional rubber mount. The ER CD-ROM mount is then installed to the drive feeding system and the system equation of motion is derived. The skyhook controller is then incorporated with the fuzzy technique to improve the performance of ER CD-ROM mount. A set of fuzzy parameters and control rules are obtained from a relation between vertical displacement and pitching motion of the feedng system. Followingthe formulation of the fuzzy-skyhook controller, computer simulation is undertaken in order to evaluate vibration suppression of the CD-ROM drive feeding system subjected to various excitations.

• Journal of the Korean Society of Visualization
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• v.5 no.2
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• pp.39-47
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• 2007

This paper describes an experimental study on the droplet formation and the subsequent motion in a microchannel having a cross junction. While one kind of liquid (pure water or water-surfactant mixture) is drawn into a horizontal inlet channel, the other kind (oil) is introduced through two vertical inlet channels. Due to the effect of surface tension on the interface between the two fluids, the droplets of the first fluid are formed near the cross junction. In this study, we have found that the droplet formation is affected even by slight difference in the surface tension. When the surface tension between two fluids is decreased, the droplet size is decreased in order to keep the equilibration between the pressure and the surface tension. In addition, the time interval between each of the droplet formations is decreased and the distance between droplets is also decreased when the surface tension is decreased.

• Textile Coloration and Finishing
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• v.5 no.4
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• pp.42-48
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• 1993

In the present work, decoloring of acid dye solution by the diethylaminoethylated cellulosic adsorbents($CA_{DASE}$) was studied with the aim of developing polymeric adsorbents for the treatment of colored wastewaters. To prepare the cellulosic adsorbents, the $CA_{DASE}$ cellulose and polyvinyl alcohol mixture(80 wt% cellulose content) were crosslinked by tryacryloyl hexahydro-s-tryazine(TAHHT), ammonium phosphate and then treated with solutions containing sodium hydroxide and 2-diethylaminoethyl chloride. Batch and flow method were employed to determine decoloring capacity of C $A_{DEAE}$ for C.I.acid yellow 49. $CA_{DASE}$ exhibited much better desorption capacity than activated carbon. Furthermore, the exhausted $$CA{DASE} could be readily regenerated by washing with dilute sodium hydroxide.

• The Korean Journal of Food And Nutrition
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• v.25 no.2
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• pp.398-406
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• 2012

The acid value of the oil extracted from the three kinds of 15 fried foods ranged from 0.89 to 3.92, the peroxide value ranged 10.0~57.14 meg/kg. Among the samples, popcorn chicken contained the highest crude fat content, showing $6.64{\pm}0.26(%)$, while the french-fries showed $2.87{\pm}0.31(%)$, which was the lowest. The content of the trans fatty acid per 100 g of the foods were; the fried foods: 0.02~0.06 g. The french-fries contained the lowest saturated fatty acid per 100 g of the foods, showing 0.41~1.55 g, while the popcorn chicken showed the highest content, 1.16~3.43 g. The fried foods contained the highest linoleic acid content. Further, fried foods exhibited safe levels of trans fat content. The "School Zone", which sells snacks, candies, chocolates flow, was not detected in the saccharin. Cookies, candies, chocolate was not detected in the tar colors. Aerobic plate count were ranged from 0~4,700 cfu/g in cookies, Salmonella test came out negative.

• Journal of the Society of Naval Architects of Korea
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• v.32 no.2
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• pp.22-31
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• 1995

In this paper, a 3-dimensional multi-layer current simulation program is allied to real shore area near Inchon harbor with highly irregular bottom and continental geometry. The effects of bottom topography on vertical structures of the ocean tidal current is investigated through comparing the calculated results by 2-dimensional depth averaged approach and the present method. Wind induced current, which may be more dominant factor in Predicting oil spill behavior, is also simulated by the present computation algorithm. Comparison shows quite large differences not only in vertical distribution of the current but also in the direction of the surface current.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.148-153
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• 2008

As the oil price is dramatically jumping up, the consumption of LNG is rapidly expanding and the size of LNG carriers becomes bigger. For LNG ships, the application of DF (Dual-Fuel) engines gradually increases because of high efficiency, which alternatively use diesel or BOG (Boil-Off Gas) from cargo tank as a fuel. The surplus BOG from LNG cargo tank should be exhausted by GCU or liquefied through the BOG reliquefaction system and returned back. This study focused into its operational characteristics through the process simulation using HYSYS and discussed details on the influence of the variations of some operational parameters such as a distribution ratio by the change of fuel mass flow into the DF engine.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.320-322
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• 2008

The international oil price now has been going up every each day, about 120 USD per a gallon April 2008, so that most of countries in the world are concern of the the shortage of petroleum and the development of new and renewable energy resources. This paper presents optimal design and operational features of stand-alone 500W PEMFC(Proton Exchange Membrane Fuel Cell) system which can be a substitute instead fossil fuel. The stack of PEMFC is composed of 35 laminated graphites, and a unit cell of the stack has electrical characteristics as below; 14W, 0.9V, 15A. The other components of BOP(Balance of Plant) are composed of hydrogen and nitrogen tanks, regulators, 3way solenoid valves, mass flow meters, etc.

• Journal of the Korean Graphic Arts Communication Society
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• v.23 no.2
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• pp.1-14
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• 2005

Generally, printing inks are composed of pigment, vehicle and additive. Among others, the vehicle transfers the pigment to substrate and then binds it on the surface. So, rheological properties of the vehicle are an important factor which has influence on printability. Thus, in this study, rheology of the vehicle was investigated by using rotational rheometer according to molecular weight of resin. Also, emlusion rheology of water in oil type and its microstructure were examined with increasing the shear rate. Consequently, the following results were obtained: (1) By viscometric flow test, zero shear viscosity and shear thinning index of vehicle increased with increasing the molecular weight of resin. (2) By relaxation and creep test, relaxation time and retardation time of vehicle increased with increasing the molecular weight of resin. (3) By frequency sweep test, crossover point of vehicle increased with increasing the molecular weight of resin. (4) G' and G" of emlusions increased with increasing the molecular weight by amplitude sweep test. (5) The shape of water drop in emlusions was changed to the capillary tube.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1695-1700
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• 2004

Nonpoint pollutants were monitored on railway station land use. Lots of pollutant mass were washed-off in a first hour. The 95$\%$ confidence interval of pollutant concentrations ranges from 61.6 to 115.4 mg/L for TSS(mean= 88.50 mg/L). 103.8$\∼$244.1 mg/L for COD(mean= 174 mg/L) and 7.68$\∼$17.32 mg/L for Oil & Grease(mean= 12.5 mg/L). The various metals were also washed-off during storm runoff from railway station. The ranges of 95$\%$ confidence intervals were 39.2$\∼$84.0 ug/L for total Cu(mean= 61.6 ug/L), 14.0 $\∼$ 25.8 ug/L for total Pb(mean= 19.9 ug/L) and 182.2 $\∼$ 376.1 ug/L for total Zn(mean= 279.2 ug/L). As a result of this research, we concluded that up to 50$\%$ of the total pollutant mass can be removed when first 30$\%$ of the total flow are treating, and it can be a first flush criteria for best management practices.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.03a
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• pp.39-51
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• 2002

Online exchange is a cost-effective approach to trade goods and information among multiple sellers and buyers. Shipping industry includes lots of global entities such as shippers, liners, ship owners and shipping agents. Marine insurance companies and ship repairers and many other groups are also supporting the industry. However, international shipping exchanges are located on few cities in the world. Its our motivation that a shipping market can be online so that market participants do the dealing while sitting where they are with more efficient manner, preferable price and larger pool of candidates of trading partners. This paper presents Korean governmental project of building a cyber shipping exchange. The exchange covers ship sale and purchase, charter, insurance, freight futures, repairs, supplying of ships oil and database service. The workflows of each business were analyzed and designed to fit for online environment. The project includes design of trading mechanism, online documents, data flow, data storage and security. Online match making and trading mechanisms such as auction, reverse auction, bid are used. The whole trading process involves multiple organizations and business processes. So, this Paper focuses on how each organization would play their roles so that users can complete transactions with integrated and transparent view. The online exchange selves also as maritime portal site that links to other sites for cooperation vertically or horizontally, and serves database and information in global perspective. This paper also issues and discusses the justification of an online shipping exchange