• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.4
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• pp.57-63
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• 2004

This study was performed to evaluate flow properties of polypropylene fiber reinforced high flow concrete. Test results were showed that the slump, slump flow and L-type compacting were decreased with increasing the content of polypropylene fiber. But, the Box-type passing and air content were increased with increasing the content of polypropylene fiber. The slump was $25.5{\sim}27.5cm$, the slump flow was $60{\sim}65cm$, the Box-type passing was $2{\sim}6cm$, the L-type compacting was excellent and air content was $2.7{\sim}3.2cm%$ by the polypropylene fiber content 0.2%, respectively. This concrete can be used for high flow concrete.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.10
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• pp.1994-2005
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• 2015

Voice over IP (VoIP) is a technology for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks. Instead of being transmitted over a circuit-switched network, however, the digital information is packetized, and transmission occurs in the form of IP packets over a packet-switched network which consist of several layers of computers. VoIP Service that used the various techniques has many advantages such as a voice Service, multimedia and additional service with cheap cost and so on. But the various frauds arises using VoIP because VoIP has the existing vulnerabilities at the Internet and based on complex technologies, which in turn, involve different components, protocols, and interfaces. According to research results, during in 2012, 46 % of fraud calls being made in VoIP. The revenue loss is considerable by fraud call. Among we will analyze for Toll Bypass Fraud by the SIM Box that occurs mainly on the international call, and propose the measures that can detect. Typically, proposed solutions to detect Toll Bypass fraud used DPI(Deep Packet Inspection) based on a variety of detection methods that using the Signature or statistical information, but Fraudster has used a number of countermeasures to avoid it as well. Particularly a Fraudster used countermeasure that encrypt VoIP Call Setup/Termination of SIP Signal or voice and both. This paper proposes the solution that is identifying equipment of Toll Bypass fraud using those countermeasures. Through feature of Voice traffic analysis, to detect involved equipment, and those behavior analysis to identifying SIM Box or Service Sever of VoIP Service Providers.

• Journal of Microbiology
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• v.37 no.3
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• pp.175-179
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• 1999

To elucidate the role of vir-box in the expression of the virE gene, the vir-box was modified by site-directed mutagenesis and tested for ${\beta}$-galactosidase activities. A, C, T T, A, C substitutions at -62, -63, and -65 positions, destroying the 5'-region of the vir-box and A T at position -55, destroying the 3'-region of the vir-box respectively, showed only 17% promoter activity. When the vir-box was modified to contain perfect dyad symmetry structure (DSR) by the substitutions T, G A, T at -60 an d-61 positions, ${\beta}$-glactosidase activity increased 302%. These results indicate that the 5' and 3'-region of vir-box as well as the imperfect DSR of the vir-box itself may play a very important role in the regulation of virE gene expression.

• YAKHAK HOEJI
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• v.44 no.6
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• pp.545-551
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• 2000

Magnesium trisilicate was prepared by reacting Magnesium sulfate solution with Sodium silicate solution in this study. The optimum synthesis conditions base on the yield of the product were established by applying Box-Wilson experimental design. It was found that the optimum synthesis conditions of Magnesium trisilicate were as follows; Reacting temperature : $57{\sim}90^{\circ}C$, Concentration of reactant solution : $19.1{\sim}20.0%$, Molar concentration ratio of two reactants : [Sod.silicate]/[Mg.sulfate] : $1.47{\sim}1.80$, Temperature of washing water : $45{\sim}48^{\circ}C$, Drying temperature : $65{\sim}82^{\circ}C$. The antacidic capacity of the five Magnesium trisilicate samples which shows the maximum antacidic efficacy was tested by pharmacopeia acid consuming capacity test. The five Magnesium trisilicate samples were identified by chemical analysis.

• Journal of Korean Association for Spatial Structures
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• v.7 no.4
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• pp.63-72
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• 2007

As business of steel consuming industries is freshly booming in domestic and foreign countries especially in China, the price of steel plates comes to very high compare with the other materials. The HR Plates made from hot rolled coils is lower steel plates in price. In this study, material characteristics of HR Plates is investigated and availabilities of HR Plates for steel bridges as sub member or a main member is discussed. No difference between steel plates and HR Plates with thickness up to 22mm is found in most characters such as cutting operation, fabrication and even welding. As sub member in steel box girders, the application ratio and the loss ratio of HR Plate is investigated as about $10{\sim}15%$, average $10{\sim}15%$ respectively.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.7 no.1
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• pp.9-15
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• 2001

Top-to-bottom compression strength of corrugated fiberboard boxes is partly dependent on the load-carrying ability of the central panel areas. The ability of these central areas to resist bending under load will increase the stacking strength of the box. The difference of box compression strengths, among boxes which are made with identical dimensions and fabricated with same components but different flute sizes, is primarily due to difference of the flexural stiffness of the box panels. Top-to-bottom compression strength of a box is accurately predicted by flexural stiffness measurements and the edge crush test of the combined boards. This study was carried out to analyze the flexural stiffness, maximum bending force and maximum deflection for various corrugated fiberboards by experimental investigation. There were significant differences between the machine direction (MD) and the cross-machine direction (CD) of corrugated fiberboards tested. It was about 50% in SW and DW, and $62%{\sim}74%$ in dual-medium corrugated fiberboards(e.g. DM, DMA and DMB), respectively. There were no significant differences of maximum deflection in machine direction among the tested fiberboards but, in cross direction, DM showed the highest value and followed by SW, DMA, DMB and DW in order. For the corrugated fiberboards tested, flexural stiffness in machine direction is about $29%{\sim}48%$ larger than cross direction, and difference of flexural stiffness between the two direction is the lowest in DMA and DMB.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.10
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• pp.1090-1097
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• 2006

The anoxic activated sludge process was applied to the treatment of industrial box-mill wastewater, which exhibited the high removal efficiencies of $90{\sim}94%$$ TCOD_{Mn}$ and $58{\sim}81%$ Color. For the design of industrial anoxic activated sludge process, Monod bio-kinetic coefficients of box-mill wastewater were estimated as follows: $K_{max}$(maximum specific substrate removal rate)=0.52 $day^{-1}$, $K_s$(half saturation constant)=314 mg/L, $K_d$(decay coefficient)=0.274 $day^{-1}$, y(microbial yield coefficient)=0.908 mg/mg, and ${\mu}_{max}$(maximum specific growth rate)=0.472 $day^{-1}$. Space loading factors for the design analysis were practically determined as the values of F/M ratio=$0.043{\sim}0.07$ kg-$TCOD_{Mn}$/kg-SS-day, BOD space loading=$0.18{\sim}0.3$ kg-$TCOD_{Mn}/m^3-day$, and ${\theta}_x=6.8{\sim}26.4$ day when considering the relationship of these loading factors with growth dynamics of microorganisms, the F/M ratio that is inversely proportional to ${\theta}_x$ should be equivalent to ${\mu}_{max}$ in units, but exhibited the significant difference between theses two values. Therefore, it is considered that high safety factors are requested in the design of anoxic activated sludge process that is based on Monod bio-kinetics of microorganism.

• The Journal of Korea Robotics Society
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• v.18 no.1
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• pp.29-36
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• 2023

This paper shows a design of a gripper with an adjustable working area to depalletize a delivery cardboard box of various sizes. The gripper should pick the box with only one flat surface to lift the boxes stacked close to each other. The lift force of the gripper is the vacuum suction force. To handle boxes of various sizes, the gripper adjusts the working area. The gripper operates four vacuum generators independently. The simultaneous rotation on different axes of four gripper-arms with suction cups moves the position of suction force. The six operation modes of the gripper are divided into the size of the working area. The operation mode is determined according to the size of the top side of the box. Experiments are conducted by lifting the box of various sizes. The gripper can pick the box of various sizes without vacuum leaks from unused cups. Also, the experiments verify the improvement of stability of the box by adjusting the working area of the gripper. The gripper can lift the box without deformation of the box by adjusting the working area.

• Fire Science and Engineering
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• v.28 no.1
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• pp.1-11
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• 2014

This study aims to address the fire characteristics of Double-skin facade using the Fire Dynamics Simulator (FDS). To end this, Double-skin facade was classified into the four structures, that is Box, Shaft-box, Corridor, Multistory, through PyroSim program which was based on FDS, and further each structure of fire characteristics were analyzed numerically as well as comparatively in the current study. This study also examined smoke movement, smoke density, smoke detectors, and visibility in order to closely identify the each structure of fire characteristics. The results of the study discovered that the Box structure did not significantly affect smoke which was rising in the other rooms, except for the fire room whereas the Corridor structure had positive effects on Double-skin facade horizontally. In addition, the Shaft-box structure showed the fastest vertical movement by means of the shaft, on the other hand, rising smoke influenced the other rooms as well. The Multistory structure along with rising smoke had a great impact on the other divided rooms in a vertical way.

• Journal of the Korean Society of Food Science and Nutrition
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• v.11 no.3
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• pp.41-46
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• 1982

To elucidate the preservative characteristics of chestnuts, three varieties, Ungi, Okkang and Chuckpa, were stored in cellar, polyethylen film packing, and box with or without $\gamma-irradiation$, and chemical compositions, rates of sprouting and rotting were determined during the period of storage. The chemical compositions of raw chestnuts were: moisture, 59 to 63%; total sugar, 28 to 29%; reducing sugar, 0.1 to 0.2%; crude fiber, 0.6 to 0.9%; crude protein, 3.5%; vitamin C, 27 to 28mg%; and tannin, 50 to 58mg%. Total sugar and vitamin C were decreased during the period of storage, and of reducing sugar and tannin were increased. The rates after 6 months of storage after three vareitia were; 93 to 100% by the cellar storage; 35 to 57% by the box storage without $\gamma-irradiation$ and 1 to 4% with $\gamma-irradiation$; and none by the polyethylene film packing. The sprouting rate in Chuckpa decreased markedly as compared with the other two varieties. The rotting rates when stored for 6 months were: 4 to 6% by the box storage without $\gamma-irradiation$ and 7 to 12% with $\gamma-irradiation$; 5 to 8% by the polyethylene film packing; and 30 to 54% by the cellar storage. The rotting rate in Chuckpa was lower than the other varieties during the period.