• Journal of the Korean Institute of Educational Facilities
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• v.19 no.5
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• pp.29-36
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• 2012

The goals of this study are to develop a sprayable strain-hardening cement composite (SHCC) and to investigate the potential of the sprayable SHCC for packing the joint between existing R/C building and seismic retrofit elements. This paper provides the procedure for the development of a sprayable SHCC, test results of fresh properties required to a sprayable SHCC, and mock-up test results of developed sprayable SHCC. Control mixture of polyvinyl alcohol (PVA) fiber-reinforced SHCC (PVA-SHCC) was predetermined based on available research results. The pumpability and sprayability of the SHCC mixture were depended on the fluid property of fresh SHCC mixture. In this study, the effects of admixtures such as AE agent and fly ash on the rheological and rebound properties of control SHCC mixture were investigated to determine a sprayable SHCC mixture. Flow values and air content during shotcreting procedure of sprayable SHCC were also evaluated. The results show that flow or flowability and amount of air of three SHCC mixtures decreased almost linearly according to shotcreting procedure from mixer to nozzle. And the pumpability and sprayability of mixture with AE agent and low amounts of fly ash were superior to the those of SHCC. Mock-up test result show that developed sprayable SHCC indicates much improved workability and shotcrete construction period than conventional method(nonshrinkage mortar).

• The Journal of Korean Association of Computer Education
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• v.13 no.6
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• pp.91-98
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• 2010

NAC(Network Access Control) has been developed as a solution for the security of end-point user, to be a target computer of worm attack which does not use security patch of OS and install Anti-Virus, which spreads the viruses in the Intra-net. Currently the NAC products in market have a sufficient technology of pre-connect, but insufficient one of post-connect which detects the threats after the connect through regular authentication. Therefore NAC users have been suffered from Zero-day attacks and malware infection. In this paper, to solve the problems in the post-connect step we generate the normal behavior profiles using the traffic information of each host, host information through agent, information of open port and network configuration modification through network scanner addition to authentication of host and inspection of policy violation used before. Based on these we propose the system to detect the hosts infected malware.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.9
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• pp.578-589
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• 2014

In this paper, we introduce the concept of cyber-physical intersection systems (CPIS) which interconnects roadside units (RSU) located at the intersection, on-board units (OBU) of moving vehicles, and the smartphone apps, named the Smartphone Agent (SA). At the pedestrian mode of the SA, the connectivity management schemes, such as a location update and a handover control algorithm, are proposed to better support the CPIS services while minimizing the power consumption of the pedestrian's smartphone. We develop a real prototype of the CPIS, including RSU, OBU, and the SA. Based on the numerical results collected from a pedestrian moving around the Pusan National University campus, we validate that the proposed connectivity management schemes can improve not only the power efficiency of the pedestrian's smartphone, but also the quality of the CPIS services.

• Journal of the Institute of Convergence Signal Processing
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• v.24 no.4
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• pp.249-254
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• 2023

Recently, the distribution of drones is being activated by saving farmers' working time and protecting them from harmful human bodies from pesticides due to the mission of spraying pesticides using drones. It is possible to compensate for various shortcomings derived from the existing pesticide spraying method, wide-area control and helicopter control. Recently, the smart farm expansion policy has actively used it to generate profits for farmers by increasing harvests by monitoring growth information of various crops based on IoT in real time and collecting big data on key variables, and related drone industry technologies are also being developed. In this study, drones were applied to the work of shading greenhouses to secure diversity in agricultural application fields, and basic research on the greenhouse environment was conducted to materialize the technology related to shading. In order to provide high-quality light in consideration of the internal and external environment of the green house, basic research was conducted to enable light-shielding missions using drones through nozzle design for uniform spraying of nozzles of drones, light-transmitting rate analysis of green houses, and light-shielding agent application experiments.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.5
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• pp.106-114
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• 2006

This paper investigates the fundamental properties and shrinkage characteristics of low shrinkage high performance concrete(LSHPC), using mock-up specimens. According to the test results, the most suitable mix proportions of LSHPC need a higher dosage of SP agent and AE agent, in order to obtain the target of slump flow and air content. This is due to reduce fluidity and air content respectively. It also presented earlier setting time than control concrete by 6 hours and exhibited compressive strength of 60MPa at age 28 days. Autogenous shrinkage of LSHPC was the half of the value of control concrete. Drying shrinkage of center section of LSHPC showed similar tendency with autogenous shrinkage, because of no internal moisture movement, while surface section had larger drying shrinkage. The specimen with embedded reinforcing bar had smaller deformation owing to confinement of reinforcing bar.

• Journal of Powder Materials
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• v.15 no.2
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• pp.119-124
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• 2008

To increase pot life in the formulation mixed with bisphenol F epoxy resin, anhydride-based curing agent, and imidazole-based curing accelerator powders as a paste material for high-speed RFID chip bonding, size variation of the imidazole-based powders and a coating method of the powders were adopted in this study. In experiment with regard to the size variation, the pot life was not outstandingly increased. Through the idea using the coating method, however, the pot life was increased up to 4.25 times in comparison with the addition of initial imidazole-based powders. Consequently, successive bonding of RFID chip could be performed with very short time of 5sec using the suggested formulation having improved pot life.

• Biomedical Science Letters
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• v.15 no.3
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• pp.241-247
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• 2009

Wound healing is a complex and highly organized biological response to injury that results in the loss of tissue integrity. Our particular interest was propolis, traditional used as an antimicrobial and an anti-inflammatory agent. The purpose of this study was to see the effects of propolis on healing of the laser induced wounds and the level of collagen formation. 808 nm laser (20 J) was irradiated on the back of rats. Irradiated wounds were divided into gel control and 6 experimental groups (3 and 5% of different three kinds of propolis). Gel type of propolis (supplied by Seoul Propolis Co., Daejeon, Korea) in water based were applied on the laser wound once daily for 14 days. One fourth of rats were sacrificed on $3^{rd}$, $7^{th}$, $10^{th}$, and $14^{th}$ day and each wound was evaluated for degree of wound healing and the level of collagen formation. Healing of wound was evaluated by measuring and comparing the width and depth of the wounds. The levels of collagen were increased in 3 and 5% gel groups comparing to control on $3^{rd}$ day and the collagen level were increased more on $7^{th}$ day. Wounds of the experimental groups showed better healing in width comparing to the healing of the control. The results of this study demonstrated that propolis accelerated healing of wounds induced by laser irradiation and good collagen formation.

• The Plant Pathology Journal
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• v.22 no.2
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• pp.131-138
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• 2006

Two strains of Cucumber mosaic virus (CMV) isolated in Kuwait were confirmed their infectivity based on symptomatology and host range on different cultivars of tomato (Lycopersicon esculentum), tobacco(Nicotiana tabacum L.) and squash (Cucurbita pepo). The pattern of symptoms differed for the two CMV strains in tomato and tobacco, showing severe stunting and mosaic symptoms with one strain designated KU2, and almost symptomless with the other strain designated KU1. A satellite RNA 5 (sat-RNA) was found to be associated with the KU1 strain and was characterized as a benign viral satellite RNA. Using reverse transcription and polymerase chain reaction (RT-PCR) with sat-RNA specific primers, an amplified PCR product of about 160bp was determined and analyzed by gel electrophoresis. This naturally occurring benign viral satellite RNA was successfully used as a biological control agent to protect tomato plants against the severe KU2 strain. Tomato plants grown in plant-growth chambers, were preinoculated with KU1 containing the benign viral satellite and then challenge inoculated with the severe KU2 strain at different time intervals. All plants challenged three weeks after preinoculation showed nearly complete protection from subsequent infection by the severe strain. This biological control technology using plant viruses was found protective and could be successfully established sooner after the preinoculation.

• The Journal of Engineering Research
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• v.6 no.2
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• pp.11-22
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• 2004

A distributed constraint satisfaction problem (distributed CSP) is a constraint satisfaction problem(CSP) in which variables and constraints are distributed among multiple automated agents. ACSP is a problem to find a consistent assignment of values to variables. Even though the definition of a CSP is very simple, a surprisingly wide variety of AI problems can be formalized as CSPs. Similarly, various application problems in DAI (Distributed AI) that are concerned with finding a consistent combination of agent actions can be formalized as distributed CAPs. In recent years, many new backtracking algorithms for solving distributed CSPs have been proposed. But most of all, they have common drawbacks that the algorithm assumes the priority of agents is static. In this thesis, we establish a basic algorithm for solving distributed CSPs called dynamic priority search algorithm that is more efficient than common backtracking algorithms in which the priority order is static. In this algorithm, agents act asynchronously and concurrently based on their local knowledge without any global control, and have a flexible organization, in which the hierarchical order is changed dynamically, while the completeness of the algorithm is guaranteed. And we showed that the dynamic priority search algorithm can solve various problems, such as the distributed 200-queens problem, the distributed graph-coloring problem that common backtracking algorithm fails to solve within a reasonable amount of time. The experimental results on example problems show that this algorithm is by far more efficient than the backtracking algorithm, in which the priority order is static. The priority order represents a hierarchy of agent authority, i.e., the priority of decision-making. Therefore, these results imply that a flexible agent organization, in which the hierarchical order is changed dynamically, actually performs better than an organization in which the hierarchical order is static and rigid. Furthermore, we describe that the agent can be available to hold multiple variables in the searching scheme.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.14 no.1
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• pp.129-153
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• 2001

Background: SMG (升麻葛根湯加味方) is an herbal medicine which has been used in oriental medicine as a traditional therapeutic agent of pruritus and skin disease. Objective: This study was performed to investigate the effect of SMG on the anti-hypersensitivity and immune response in the murine of type I hypersensitivity induced by the experiment. Materials and Methods: Laboratory rats were primary sensitized with OA (ovalbumin); on day 1, rats of a Control group and Sample group (SMG group) were systemically immunized by subcutaneous injection of 1mg OA and 300mg of Al(OH)3 in a total volume of 2ml saline. The rats of the sample group were orally administered with an SMG water extract for 14 days after primary immunization. On day 14 after the systemic immunization, rats received local immunization by inhaling $0.9\%$ saline aerosol containing $2\%$(wt/vol) OA. A day after local immunization, BAL fluid and peripheral blood were collected from the rats. Total cell, lymphocyte, $CD4^+\;T\;cell,\;CD8^+\;T\;cell,\;CD4^+/CD8^+$ ratio in the BALF, and IgE, $CD4^+\;T\;cell,\;CD8^+$ T cell in the peripheral blood were measured and evaluated. Results: SMG showed a suppressive effect on the immune response in the rats. 1. Total Cells in the BALF decreased in the SMG treated group in comparison group, but statistic differences were not observed. 2. Total lymphocytes in the BALF were statistically decreased in SMG treated group in comparison to the control group. 3. CD4+ T cells in the BALF were statistically decreased in SMG treated group in comparison to the control group. 4. CD8+ T cells in the BALF were decreased in SMG treated group in comparison to the control group, but statistic differences were not observed. 5. The ratio of CD4+/CD8+ in the BALF was statistically decreased in SMG treated group in comparison to the control group. 6. The IgE level in serum was statistically decreased in SMG treated group in comparison to the control group. 7. The ratio of CD4+ and CD8+ in peripheral blood showed undetectable differences between each group of rats. From the experiment cited above, this study shows that SMG has both anti-hypersensitivity effects and immunoregulatory effects when administered to rats. Based on this experiment, it is suggested that SMG could be a useful immunomodulator and anti-allergy agent.