• Smart Media Journal
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• v.4 no.4
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• pp.24-32
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• 2015

Recently, SDN is actively used as datacenter networks and gradually increase its applied areas. Along with this change of networking environment, research of deploying network security systems on SDN becomes highlighted. Especially, systems for detecting network flooding attacks by monitoring every packets through ports of OpenFlow switches have been proposed. However, because of the centralized management of a SDN controller which manage multiple switches, it may be substantial overhead that the attack detection system continuously monitors all the flows. In this paper, a sampling based network flooding attack detection and prevention system is proposed to reduce the overhead of monitoring packets and to achieve reasonable functionality of attack detection and prevention. The proposed system periodically takes sample packets of network flows with the given sampling conditions, analyzes the sampled packets to detect network flooding attacks, and block the attack flows actively by managing the flow entries in OpenFlow switches. As network traffic sampler, sFlow agent is used, and snort, an opensource IDS, is used to detect network flooding attack from the sampled packets. For active prevention of the detected attacks, an OpenDaylight application is developed and applied. The proposed system is evaluated on the local testbed composed with multiple OVSes (Open Virtual Switch), and the performance and overhead of the proposed system under various sampling condition is analyzed.

• Journal of the Korean GEO-environmental Society
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• v.18 no.12
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• pp.65-75
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• 2017

Flowability and strength with curing time of controlled low-strength material (CLSM) are required differently according to the construction purpose. In this paper, the flowability and strength were estimated from the mixing ratio of CLSM using multiple regression analysis to design the CLSM. The flow values and strength at 12 hrs and 7days were measured in accordance with the mixing ratio of CLSM which consists of 7 different materials, such as CSA expansive agent, ordinary Portland cement, fly ash, sand, silt, water, and accelerator. The multiple regression was performed with the proportions of each material of CLSM as independent variables and the measured properties as dependent variables using SPSS Statistics 23 which is a statistical analysis program. The regression coefficients were estimated from the first to third order equation models for the materials. From the results, the third order model for the flow values and the first order models for 12hrs and 7days strength are the most appropriate models. This study suggests that the mixing ratio required for constructions may be effectively estimated from the regression models about the characteristics of CLSM, before performing experimental tests.

• The Journal of the Korean Society for Microbiology
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• v.22 no.2
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• pp.175-184
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• 1987

The use of alkylating agent cyclophosphamide(CY), a widely used antitumor drug is well known as a potent immunosuppressant and has been used as a probe for investigating the functional capabilities of lymphocyte subsets of both T and B cells that play an important role in the regulation of the immune response. The present study was undertaken in an effort to assess the effects of CY on immunological memory in murine model. CY, given as a single dose of CY(250mg/kg) before sensitization with sheep red blood cells(SRBC) enhanced the primary response of Arthus and delayed-type hypersensitivity(DTH), as measured by footpad swelling reaction, but suppressed their tertiary DTH response. The similar CY pretreatment enhanced both the primary and tertiary hemagglutinin(HA) responses to SRBC, and the tertiary antibody response against polyvinylpyrroridone(PVP), a thymus-independent antigen but not the primary response against PVP. CY, given as a single dose of 250mg/kg 2 days before the primary immunization and two doses of 100mg/kg 2 days before the secondary and tertiary immunization, markedly suppressed the tertiary DTH and HA responses to SRBC. However, CY, given as small multiple daily doses(10mg/kg) over 4 days before sensitization but not after sensitization, enhanced the secondary HA response to SRBC. Contact sensitivity to dinitrofluorobenzene(DNFB) was suppressed by the drug, given either as a single large dose(300mg/kg) or as multiple dose(10mg/kg) administered 2 days before, together with or after DNFB sensitization. This suppression was more pronounced and more significant when CY was given as multiple dose. However, the enhancement of the secondary contact sensitivity to DNFB by CY was not clear-cut. The splenectomy appears to increase the enhancing effect of CY on contact sensitivity. These results suggest that CY selectively influences the immune response depending on the time of the drug administration relative to immunization and that the secondary or tertiary immune response involve memory cells with different susceptibilities to CY. Moreover, these results suggest that multiple low doses may sesectivley inhibit suppressor T cell proliferation involving DTH, HA or contact sensitivity without effecting helper T cells, but high doses presumably inhibit helper T cells and suppressor T cells with effecting B cells.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.6
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• pp.497-503
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• 2010

Purpose: The purpose of this study is to induce artificial arthritis on rabbit TMJ by injecting collagenase. Materials and Methods: An experimental animal model of arthritis induced by surgical method or intraarticular injection of chemical agent like LDH, papain, ketorolac. Surgical method is complex and needs a long time in inducing arthritis. Intra-articular injection of chemical agent like LDH, papain, ketorolac is simple. But chemical agent like LDH, papain, ketololac needs multiple injections to induce arthritis and mechanism inducing arthritis was known. Collagenase destroys helical domain of type II collagen in extracellular matrix produced by chondrocyte and then induces arthritis. We injected collagenase (0.5, 1.0, 2.0 mg) into the temporomandibular joint of rabbit. In the control group saline was intra-articularly injected. The condylar cartilage, disk and synovia were histologically examined at 1, 2, 4, 6 weeks after the initiation of collagenase injections. Results: Four weeks after injection of 2.0 mg collagenase, we could see histologic change like arthritis. In other groups, we couldn't see arthritis-like change. Conclusion: In our study, we produce arthritis on temporomandibular joint of rabbit by using injection of collagenase in temporomandibular joint of rabbit. And this experimental osteoarthritis is a useful animal model.

• Korean Journal of Construction Engineering and Management
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• v.4 no.2 s.14
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• pp.74-81
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• 2003

In the construction industry, projects are becoming increasingly large and complex, involving multiple subcontractors. Traditional centralized coordination techniques used by the general contractors become less effective as subcontractors perform most wok and provide their own resources. When subcontractors cannot provide enough resources, they hinder their own performance as well as that of other subconractors and ultimately the entire project Thus, construction projects need a new distributed coordination approach wherein all of the concerned subcontractors can reschedule a project dynamically. To enable the distributed coordination framework of project schedule changes, the author developed an agent-based compensatory negotiation methodology, which allows intelligent software agents to simulate negotiations on behalf of their human subcontractors. In addition to this theoretical work, 1 designed and implemented a prototype to demonstrate the effectiveness of the framework. Thus, this research formalizes the necessary steps that would help construction project participants to increase the efficiency of their resource use, which in turn will enhance successful completions of whole projects.

• The Journal of the Korea Contents Association
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• v.12 no.4
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• pp.426-437
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• 2012

The purpose of this study is to investigate the relationship between internal service quality, internal customer satisfaction and management outcome of airport security agents. This study had selected special securities from Incheon airport of October, 2011 for population. Using judgment sampling method, 282 samples were drawn and were used for the final analysis. Questionnaire used in study is composed of total 43 questions and using SPSSWIN 18.0, frequency analysis, factor analysis, reliability analysis, multiple regression analysis and path analysis were performed. Cronbach's ${\alpha}$ value which shows the reliability of the survey came out to be over .686. The conclusion is following: First, internal service quality of airport security agents affects internal customer satisfaction. That is, as corporality, responsiveness and empathy increase, internal supply satisfaction and job satisfaction also increase. Second, internal service quality of airport security agent affects job performance. That is, as corporality, reliability and responsiveness increase, non-financial performance and financial performance also increase. However, when empathy is not activated well, financial performance is decreased. Third, airport security agent…s internal customer satisfaction affects job performance. That is, as activation of internal supply satisfaction increases, nonfinancial performance and financial performance are increased. Fourth, airport special security agent…s inside quality of service exerts direction indirect effect in inside customers satisfaction and management result. That is, inside customers satisfaction is an important variable that mediate inside quality of service and management result.

• Journal of Nutrition and Health
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• v.49 no.4
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• pp.233-240
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• 2016

Purpose: Diabetic complications are a major concern to manage progression of diabetes. Production of advanced glycation end products (AGEs) due to high blood glucose is one of the mechanisms leading to diabetic complications. Multiple pharmacologic AGE inhibitory agents are currently under development, but clinical applications are still limited due to safety issues. Thus, it is necessary to identify a safe anti-glycation agent. It is known that burdock roots have antioxidant, anti-inflammatory, and anti-cancer activities. The objective of the present study was to investigate the inhibitory role of burdock roots on the formation of high glucose-induced glycation of bovine serum albumin (BSA). Methods: In this study, glycation of BSA by glucose, galactose, or fructose at $37^{\circ}C$ for 3 weeks was assessed based on levels of ${\alpha}$-dicarbonyl compounds (early-stage glycation products), fructosamine (intermediate products of glycation), and fluorescent AGEs (late-stage glycation products). In order to compare the inhibitory actions of burdock root extract in AGE formation, aminoguanidine (AG), a pharmacological AGE inhibitor, was used as a positive control. Results: BSA glycation by glucose, fructose, and galatose was dose- and time-dependently produced. Burdock root extract at a concentration of 4 mg/mL almost completely inhibited glucose-induced BSA glycation. The results demonstrate that burdock root extract inhibited AGE formation with an $IC_{50}$ value of 1.534 mg/mL, and inhibitory activity was found to be more effective than the standard anti-glycation agent aminoguanidine. This study identified a novel function of burdock root as a potential anti-glycation agent. Conclusion: Our findings suggest that burdock root could be beneficial for preventing diabetic complications.

• KIPS Transactions on Computer and Communication Systems
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• v.9 no.8
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• pp.171-180
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• 2020

Smart Factory consists of digital automation solutions throughout the production process, including design, development, manufacturing and distribution, and it is an intelligent factory that installs IoT in its internal facilities and machines to collect process data in real time and analyze them so that it can control itself. The smart factory's equipment works in a physical combination of numerous hardware, rather than a virtual character being driven by a single object, such as a game. In other words, for a specific common goal, multiple devices must perform individual actions simultaneously. By taking advantage of the smart factory, which can collect process data in real time, if reinforcement learning is used instead of general machine learning, behavior control can be performed without the required training data. However, in the real world, it is impossible to learn more than tens of millions of iterations due to physical wear and time. Thus, this paper uses simulators to develop grid sortation systems focusing on transport facilities, one of the complex environments in smart factory field, and design cooperative multi-agent-based reinforcement learning to demonstrate efficient behavior control.

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.6
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• pp.545-559
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• 2002

There has been increasing use of IPS Empress $2^{(R)}$ owing to easy fabrication method, high esthetics similar to natural teeth, good marginal accuracy, and sufficient fracture strength. However, in clinical application, although a luting agent and the tooth cementation bonding procedure influence the marginal accuracy and fracture strength restoration, there has been a controversy in the selection of proper luting agent. This study was to measure the marginal fidelites and fracture strength of IPS Empress crowns according to three cement types, Protec $cem^{(R)}$, Variolink $II^{(R)}$ and Panavia $21^{(R)}$. After construction of 12 experimental dies for each group, IPS Empress $2^{(R)}$ crowns were fabricated and luted the metal master die prepartion of the maxillary right premolar. Marginal gaps before cementation and after cementation were measured. Buccal incline on the functional cusp of specimens were loaded until the catastrophic failure and fracture strength was measured. The results of this study were as follows: 1. The range of gap was $34.04{\pm}4.84{\mu}m$ before cementation and $37.88{\pm}5.00{\mu}m$ after cementation, which showed significant difference by paired t-test (p<0.05). The difference in the results from marginal accuracy according to measuring point proved to be not statistically significant by two-way ANOVA test (p>0.05). 2. The difference in the results from marginal accuracy according to three cement types Proved that The Variolink $II^{(R)}$ cement group had the least gap, $35.43{\pm}5.03{\mu}m$, and showed superior marginal accuracy while there existed statistic significance in Protec $cem^{(R)}$ cement group, $39.06{\pm}4.41{\mu}m$ or Panavia $21^{(R)}$ cement group, $39.16{\pm}4.39{\mu}m$ by two-way ANOVA test & multiple range test (p<0.05). 3. The difference in the results from fractures strength testing according to three cement type groups proved to be statistically significant (p<0.05). The Variolink $II^{(R)}$ cement group shows highest fracture strength of $1257.33{\pm}226.77N$, Panavia $21^{(R)}$ cement group has $1098.08{\pm}138.45N$, and Protec $cem^{(R)}$ cement group represents the lowest fracture strength of $926.75{\pm}115.75N$. 4. Three different cement groups of different components showed acceptable marginal fidelity and fracture strength. It is concluded that IPS Empress $2^{(R)}$ crowns luted using Variolink $II^{(R)}$ cement group had stronger fracture strength and smaller marginal gap than the other cement groups. Although Variolink $II^{(R)}$ resin cement seemed acceptable to clinical applications in IPS Empress $2^{(R)}$ system, the IPS Empress $2^{(R)}$ system still requires long-term research due to the lack of data in clinical applications.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.4
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• pp.378-388
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• 2016

International societies are currently working together to achieve the Climate-Smart Agriculture (CSA) initiative which aims the triple wins: (1) sustainably increasing agricultural productivity and incomes; (2) adapting and building resilience to climate change; and (3) mitigating greenhouse gases emissions. In terms of its scope and context, CSA follows the '3Nong (三農)' vision cast about 200 years ago by Dasan Jeong Yak-Yong who emphasized the triad of governance, management and monitoring towards comfortable, profitable and noble agriculture. Yet, the CSA provides the practical aims that facilitate the development of holistic indicators for quantitative evaluation and monitoring, on which decision-making support system is based. In this study, we introduce an agent-based model, i.e. Mathematical Programming Multi-Agent Systems (MP-MAS), as a tool for supporting the decision-making toward CSA. We have established the initial version of MP-MAS adapted for domestic use and present the preliminary results from an application to the rice farming case in Haenam, Korea. MP-MAS can support both farmers and policy-makers to consider diverse management options from multiple perspectives. When the modules for system resilience and carbon footprint are added, MP-MAS will serve as a robust tool that fulfills not only CSA but also Dasan's '3Nong' vision of sustainable agricultural-societal systems.