• Journal of Institute of Control, Robotics and Systems
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• v.19 no.5
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• pp.410-415
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• 2013

This paper proposes a bidirectional platoon control law using a coupled distance error based on the backstepping-like feedback linearization control method for an interconnected mobile agent system with a string structure. Unlike the previous results where the single agent was controlled using the only own information without other agents, the proposed control law cannot show the only distance error convergence of each agent, but also the string stability of the whole system. Also, the control performances are improved by the proposed control law in spite of low performance of bidirectional control strategy in the previous results. The proposed bidirectional platoon control algorithm is based on the backstepping-like feedback linearization control method. The position errors between each agent and the preceding and the behind agents are coupled by weighted summation. By the proposed control law, the distance error of each agent can converge to zero while the string stability is guaranteed when the coupled errors can converge to zero. To this end, the back-stepping control method is employed. The pseudo velocity input is determined considering the kinematic relationship between agents and the string stability. Then, the actual dynamic control input is determined to make the actual velocity converge to the pseudo velocity input. The stability analysis and the simulation results of the proposed method are included in order to demonstrate the practical application of the proposed algorithm.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.05a
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• pp.65-68
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• 2002

This study dealt with autonomic microcapsules with the healing agent for damage repair of the composite structures. Autonomic microcapsules were made of a urea-formaldehyde resin for shell of microcapsule and a DCPD for the healing agent. Thermal analysis was conducted by using a DSC and a TGA for the healing agent, microcapsules without the healing agent, and microcapsules with the healing agent. According to the results, autonomic microcapsules were verified to be so thermally stable that the healing agent was kept inside the microcapsule until the shell of microcapsules were burned out.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1076-1077
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• 2006

Conductive pastes consist of conductive fillers( Au, Ag, Ni, Cu etc.), organic binders, solvents and additives. Meanwhile, there are some metal powders such as copper, nickel etc that are used for pastes which have serious surface corrosion problems. This problem leads to change of the color and decrease in conductivity and affect storage stability of conductive pastes. By using silane coupling agent and dispersion agent, we can ensure both the corrosion stability and long term storage stability, and enhance the high performance electrical and mechanical properties of EMI shielding silicone sealant.

• Journal of the Korean institute of surface engineering
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• v.55 no.2
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• pp.102-119
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• 2022

Gold plating is used as a coating of connecter in printed circuit boards, ceramic integrated circuit packages, semiconductor devices and so on, because the film has excellent electric conductivity, solderability and chemical properties such as durability to acid and other chemicals. As increasing the demand for miniaturization of printed circuit boards and downsizing of electronic devices, several types of electroless gold plating solutions have been developed. Most of these conventional gold plating solutions contain cyanide compounds as a complexing agent. The gold film obtained from such baths usually satisfies the requirements for electronic parts mentioned above. However, cyanide bath is highly toxic and it always has some possibility to cause serious problems in working environment or other administrative aspects. The object of this investigation was to develop a cyanide-free electroless gold plating process that assures the high stability of the solution and gives the excellent solderability of the deposited film. The investigation reported herein is intended to establish plating bath composition and plating conditions for electroless gold plating, with thiomalic acid as a complexing agent. At the same time, we have investigated the solution stability against nickel ion and pull strength of solder ball. Furthermore, by examining the characteristics of the plated Au plating film, the problems of the newly developed electroless Au plating solution were improved and the applicability to various industrial fields was examined. New type electroless gold-plating bath which containing thiomalic acid as a complexing agent showing so good solution stability and film properties as cyanide bath. And this bath shows the excellent stability even if the dissolved nickel ion was added from under coated nickel film, which can be used at the neutral pH range.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.1
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• pp.8-13
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• 2008

This paper presents auto-reclosing algorithms with reference to power system stability based on MAS(Multi-Agent System). And this paper shows auto-reclosing algorithms considering power system stability. It includes the variable dead time, optimal reclosing, sequential reclosing, emergency extended equal-area criterion(EEEAC) algorithm, and modified EEEAC algorithm. This paper divides Auto-reclosing algorithms into respectively agents according to their tasks. A separated agent is merely a software entity that is situated in some environment and is able to autonomously react to changes in the environment. And all the simulations in this parer were tested by EMTP MODELS.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.26 no.1
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• pp.199-212
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• 2000

A series of novel ascorbic acid derivatives, polyethoxylated ascorbic acid (PEAA) were synthesized by coupling ascorbic acid with polyethylene glycol (PEG) of two molecular weights (MW: 350 and 550) at the C-2 or C-3 hydroxyl group (2PEAA350, 3PEAA350, 2PEAA550, 3PEAA550) to increase the stability and retain the activity, as a skin whitening agent. Their stability, scavenging activity against free radical, inhibitory activity against tyroxinase and inhibitory activity of melanin synthesis in Bl6 melanoma cell of PEAAs were evaluated in viかo and compared with those of ascorbic acid and 3-O-ethyl ascorbic acid (3OEAA), a Con stable vitamin C derivative. Among PEAAs, 2PEAA350 and 2PEAA550 tad high scaveniging activity against See radical, inhibitory activity against tyrosinase and inhibitory activity if melanogenesis but low stability, 3PEAA350 had high stability and moderate scavenging activity against free radical, infibitory activity against tyrosinase and inhibitory activity of melanogenesis. The stability, scavenging activity against free radical and inhibitory activity of melanogenesis of 3PEAA350 were higher than those of 30EAA. The most stable 3PEAA350 among PEAAs was nontoxic in various toxicological tests. These results suggest that PEAA would be a good whitening agent far enhancing stability and bioavailability.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.05a
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• pp.35-38
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• 2006

This study investigated fundamental properties of lightweight foamed concrete using cement kiln dust (CKD) and both fly ash(FA) and stability agent. Test results showed that concrete incorporating more amounts of admixture decreased slump flow and it caused increase of superplasiticizer in order to secure the fluidity performance. In addition concrete adding stability agent showed stable flow state, resisting segregation of materials and decreasing bleeding capacity. Sinking depth of concrete incorporating 20% of CKD and adding 0.002% of stability agent was indicated at 0mm. For the properties of hardened concrete. compressive strength of concrete incorporating CKD declined due to a lower appearance density, compared with other specimens. The difference of that was not very significant and the value of ail specimen was higher than KS range. Moreover strength of concrete incorporating CKD was even higher at curing temperature $5^{\circ}C$. Tensile strength ratio of concrete incorporating CKD was indicated between 0.50 to 0.59, which is higher value than control concrete. Heat conductivity of concrete incorporating FA was under the KS range while concrete incorporating 20% of CKD was satisfied in KS. Concrete adding stability agent improved insulation performance due to the lower heat conductivity. In conclusion, it is possible that concrete incorporating 20% of CKD and adding 0.002% of stability agent can secure high quality of lightweight foamed concrete.

• Macromolecular Research
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• v.14 no.3
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• pp.261-266
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• 2006

Blends of silicone rubber (VMQ) and liquid crystalline polymer (LCP) were prepared using a melt blending technique in the presence and absence of glass fiber and coupling agents. The effect of glass fiber and coupling agents on the thermal, dynamic mechanical, morphological pro-perties and cure characteristics of VMQ/LCP blends were studied. The vinyl silane coupling agent showed a significant effect on the above mentioned properties of VMQ/LCP blends by reacting at the interface between VMQ and LCP. The viscosity of the VMQ/LCP blends decreased with the addition of a coupling agent. A substantial improvement in storage modulus of VMQ/LCP blends was observed in the presence of glass fiber and coupling agents. However, as a coupling agent vinyl silane proved to be better than amine for the VMQ/LCP-glass-containing blends. The thermal stability of the pure silicone rubber was higher than those of the blends. This high thermal stability of silicone rubber was attributed to the Si-O-Si bonds. However, the thermal stability of the blends decreased further in the presence of a coupling agent, possibly due to a decrease in blend crystallinity.

• Journal of the Korean Ceramic Society
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• v.34 no.10
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• pp.1037-1044
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• 1997

Mechanical properties and water stability of HAC/PVA based MDF cement composite were investigated using polyurethane(PU) resin, silane coupling agent and various PVA. The results were as follows ; The flexural strength of MDF cement composite increased as increasing with PVA content. Low-viscosity PVA developed higher flexural strength than high-viscosity PVA under a drying curing condition. But the strength of water immersed specimen decreased. Water stability of MDF cement improved as increasing with content of PU. Consequently, water stability of polyurethane 7% added MDF cement was about 2 times higher than that of the controlled specimen. Furthermore, the strength and water stability of diamine group based silane couling agent in using MDF cement increased and improved dramatically.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.2
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• pp.67-73
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• 2012

Structural stability and shock absorption are important properties for corrugated board. In order to maintain structural stability, adhesive properties between top/bottom liners and corrugated medium are not only essential but also important for productivity and product quality. Borax has been an essential ingredient in corrugating adhesive solution. Borax increases viscosity, bonding between starchs and green adhesive bond. The objective of this research is to improving adhesive strength and viscosity stability by adding cross-linking agent instead of borax. Rheology and penetration of main starch gelatinization slurry were affected by borax addition level. Borax increased viscosity and decreased viscosity stability, while cross-linking additives increased viscosity stability and adhesive strength by anchoring effect.