• Journal of the Korean Data and Information Science Society
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• v.22 no.6
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• pp.1153-1166
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• 2011

Detecting misbehavior in vehicular ad-hoc networks is very important problem with wide range of implications including safety related and congestion avoidance applications. Most misbehavior detection schemes are concerned with detection of malicious nodes. In most situations, vehicles would send wrong information because of selfish reasons of their owners. Because of rational behavior, it is more important to detect false information than to identify misbehaving nodes. In this paper, we propose the variable precision rough sets based misbehavior detection scheme which detects false alert message and misbehaving nodes by observing their action after sending out the alert messages. In the proposed scheme, the alert information system, alert profile is constructed from valid actions of moving nodes in vehicular ad-hoc networks. Once a moving vehicle receives an alert message from another vehicle, it finds out the alert type from the alert message. When the vehicle later receives a beacon from alert raised vehicle after an elapse of time, then it computes the relative classification error by using variable precision rough sets from the alert information system. If the relative classification error is lager than the maximum allowable relative classification error of the alert type, the vehicle decides the message as false alert message. Th performance of the proposed scheme is evaluated as two metrics: correct ratio and incorrect ratio through a simulation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.1-7
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• 2012

DDoS attack is a malicious attempt to exhaust resources of target system and network capacities using lots of distributed zombi systems. DDoS attack introduced in early 2000 has being evolved over time and presented in a various form of attacks. This paper proposes a scheme to detect DDoS attacks and to reduce possibility of such attacks that are especially based on vulnerabilities presented by using control packets of existing network protocols. To cope with DDoS attacks, the proposed scheme utilizes a buffer management techniques commonly used for congestion control in Internet. Our scheme is not intended to detect DDoS attacks perfectly but to minimize possibility of overloading of internal system and to mitigate possibility of attacks by discarding control packets at the time of detecting DDoS attacks. In addition, the detection module of our scheme can adapt dynamically to instantly increasing traffic unlike previously proposed schemes.

• Archives of Plastic Surgery
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• v.40 no.5
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• pp.505-509
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• 2013

Background The aim of this study was to collect important data on the time of oxygen saturation change in relation to skin flap color alteration using non-invasive pulse oximetry to evaluate its ability to provide continuous monitoring of skin flap perfusion. Methods An experimental study on the monitoring of blood perfusion of 20 tube-island groin flaps of 10 male New Zealand rabbits was performed using pulse oximetry. The animals were randomly assigned to one of two groups representing a blockage of either arterial or venous blood flow. The oxygen saturation change and clinical color alteration were monitored from the beginning of vessel clamping until the saturation became undetectable. The result was analyzed by the t-test using SSPS ver. 10.0. Results The mean times from the vessel clamping until the saturation became undetectable were $20.19{\pm}2.13$ seconds and $74.91{\pm}10.57$ seconds for the artery and vein clamping groups, respectively. The mean time of the clinical alteration from the beginning of vein clamping was $34.5{\pm}11.72$ minutes, while the alteration in flaps with artery clamping could not be detected until 2.5 hours after clamping. Conclusions The use of neonate-type reusable flex sensor-pulse oximetry is objective and effective in early detection of arterial and vein blockage. It provides real-time data on vessel occlusion, which in turn will allow for early salvaging. The detection periods of both arterial occlusion and venous congestion are much earlier than the color alteration one may encounter clinically.

• Korean Journal of Veterinary Service
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• v.37 no.1
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• pp.79-84
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• 2014

Two Hahns Macaws (Ara nobilis nobilis), three and nine-month-old, with a three-weeks history of weight loss and anorexia were diagnosed presumptively with proventricular dilatation disease (PDD) by radiographic examination. The birds were treated with antimicrobials, analgesics, and fluid administration. However, these birds died three weeks after the first signs of PDD. At necropsy, the birds had severely dilated proventriculus, severe pectoral muscles atrophy, and blood vessels congestion on cortex of cerebrum. The partial matrix gene of avian bornavirus (ABV) was detected by RT-PCR from tissues of the brain, feather calami, and proventiculus of each PDD-suspected birds. This report describes the first detection of ABV in PDD-suspected Hahns Macaw in Korea.

• Journal of Internet Computing and Services
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• v.11 no.1
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• pp.1-13
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• 2010

It is not easy to set RED(Random Early Detection) parameter according to environment in managing Network Device. Especially, it is more difficult to set parameter in the case of maintaining the constant service rate according to the change of environment. In this paper, we hypothesize the router that has Multi-core CPU in output queue and propose AI RED(Artificial Intelligence RED), which directly induces Genetic Algorithm of Artificial Intelligence in the output queue that is appropriate to the optimization of parameter according to RED environment, which is automatically adaptive to workload. As a result, AI RED Is simpler and finer than FuRED(Fuzzy-Logic-based RED), and RED parameter that AI RED searches through simulations is more adaptive to environment than standard RED parameter, providing the effective service. Consequently, the automation of management of RED parameter can provide a manager with the enhancement of efficiency in Network management.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.2005-2014
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• 2008

In this paper, it is presented to utilize UPnP as RFID service discovery and control mechanism for context-aware services. Using UPnP, it is possible to achieve easy deployment of context-aware services and to provide zero-configuration for RFID services. In addition, SQL based cleaning module which raises detection rates is developed since context-aware applications heavily rely on streams of data gathered from RFID tags. Using the cleaning technique, detection rates are improved from 60-80% to 98% or more In order to verify RFID context aware service based on the UPnP, sample context-aware scenario for physical distribution services is implemented on UPnP over RFID system. The impacts of UPnP messages (or service advertisements on network congestion and SQL cleaning module are experimented and analyzed, and the result show the good correctness and validity of the proposed system.

• Journal of Practical Engineering Education
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• v.13 no.2
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• pp.301-304
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• 2021

In this study, we developed a module that can perform two functions at the same time through interworking between a personal recognition module and a heat detection module in the era of COVID-19. This can simultaneously solve the problem of compatibility of the personal recognition module that occurs in the existing system and the problem of secondary infection that can occur during congestion due to the separate implementation of heat detection. Therefore, in this study, NFC and Bluetooth motherboards were developed, and an array-type non-contact temperature sensor was applied to detect heat. The developed system is expected to be able to realize both access control of floating population and effective quarantine at the same time in public institutions or private companies that require AI automated access control. In addition, it is judged that it is possible to link the embedded programming and web programming implementation method using the module of the development system to the educational program.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.2
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• pp.133-146
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• 2023

Traffic states in urban areas are essential to implement effective traffic operation and traffic control. However, installing traffic sensors on numerous road sections is extremely expensive. Accordingly, estimating the traffic state using a vehicle-mounted camera, which shows a high penetration rate, is a more effective solution. However, the previously proposed methodology using object tracking or optical flow has a high computational cost and requires consecutive frames to obtain traffic states. Accordingly, we propose a method to detect vehicles and lanes by object detection networks and set the region between lanes as a region of interest to estimate the traffic density of the corresponding area. The proposed method only uses less computationally expensive object detection models and can estimate traffic states from sampled frames rather than consecutive frames. In addition, the traffic density estimation accuracy was over 90% on the black box videos collected from two buses having different characteristics.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1009-1013
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• 2011

Seoul Metro Line 1 to 4 guests per day to 4.5 million people have been using the subway. This is close to the city population, 57 percent of people use the subway and found that 57 percent of people use the subway and found that this is close to the city population. Motor vehicle indoor air quality, especially of the major factors affecting is passenger's clothing, cosmetics, adhesives and formaldehyde by the action and so are able to keep. Enclosure 30ppm formaldehyde during prolonged exposure at concentrations above the nose, bronchial cough and a burning can cause symptoms. It is necessary to introduce an appropriate ventilation system. 1-4 Line Press in 2008, leaving the subway, and normally the train measured in room air quality. Measurements in 2005, $19.3{\sim}83{\mu}g/m^3$, 2008 Year ND ~ $61.7{\mu}g/m^3$ is. When congestion(rush hour) to temporarily increase the formaldehyde can result in a higher number. Automatic detection of formaldehyde and improve ventilation to a practical system, and it is necessary to chatneun. In research since 2006, Removal of formaldehyde were analyzed for the study. the passengers on the effects of formaldehyde in rush hour, the plan for increasing the ventilation through the analysis of various factors, such as electric vehicle practical ways to improve air quality have been studied.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.782-787
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• 2004

Internet Engineering Task Force (IETF) has been considering the deployment of the Random Early Detection (RED) in order to avoid the increasing of packet loss rates which caused by an exponential increase in network traffic and buffer overflow. Although RED mechanism can prevent buffer overflow and hence reduce an average values of packet loss rates, but this technique is ineffective in preventing the consecutive drop in the high traffic condition. Moreover, it increases a probability and average number of consecutive dropped packet in the low traffic condition (named as "uncritical condition"). RED mechanism effects to TCP congestion control that build up the consecutive of the unnecessary transmission rate reducing; lead to low utilization on the link and consequently degrade the network performance. To overcome these problems, we have proposed a new mechanism, named as Extended Drop slope RED (ExRED) mechanism, by modifying the traditional RED. The numerical and simulation results show that our proposed mechanism reduces a drop probability in the uncritical condition.