• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.7
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• pp.3093-3115
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• 2020

Network anomaly detection system plays an essential role in detecting network anomaly and ensuring network security. Anomaly detection system based machine learning has become an increasingly popular solution. However, due to the unbalance and high-dimension characteristics of network traffic, the existing methods unable to achieve the excellent performance of high accuracy and low false alarm rate. To address this problem, a new network anomaly detection method based on data balancing and recursive feature addition is proposed. Firstly, data balancing algorithm based on improved KNN outlier detection is designed to select part respective data on each category. Combination optimization about parameters of improved KNN outlier detection is implemented by genetic algorithm. Next, recursive feature addition algorithm based on correlation analysis is proposed to select effective features, in which a cross contingency test is utilized to analyze correlation and obtain a features subset with a strong correlation. Then, random forests model is as the classification model to detection anomaly. Finally, the proposed algorithm is evaluated on benchmark datasets KDD Cup 1999 and UNSW_NB15. The result illustrates the proposed strategies enhance accuracy and recall, and decrease the false alarm rate. Compared with other algorithms, this algorithm still achieves significant effects, especially recall in the small category.

• Journal of Navigation and Port Research
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• v.42 no.1
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• pp.25-30
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• 2018

This study was carried out to analyze the risk attitude based on situation awareness of the Vessel Traffic Service Operator (VTSO) on the risk of collision between vessels during the monitoring of vessel traffic through the use of the VTS system. In general, when two vessels are in the close quarters situation, we analyzed the degree of risk of collision from the subjective viewpoint of the VTSOs through an administered survey. Chiefly, we analyzed the risk attitudes of each VTSO in the close quarters situation, by comparing it with the calculated value by the CoRi, which is the ship collision risk model from the VTSO's viewpoint. As a result, it was confirmed that more than 40% of the total VTSO was noted as being in a weak risk aversion type of category. Through a review of the results of analyzing the risk attitude of VTSO according to gender, age, VTS career, VTS center position, accident experience, and boarded career, it was found that there was a significant difference in the VTS career, VTS center position and accident experience. In addition, a regression model that is able to further explain the risk attitude of VTSO was derived as a factor that confirmed the significant difference and applied to CoRi to predict the collision risk according to the individual VTSO to be used as a fundamental information gathering tool for providing more accurate and safe VTS service at sea.

• Journal of Korean Society of Transportation
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• v.19 no.4
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• pp.35-47
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• 2001

Traffic represents one of the largest sources of primary air pollutants in urban area. As a consequence. numerous abatement strategies are being pursued to decrease the ambient concentration of pollutants. A characteristic of most of the these strategies is a requirement for accurate data on both the quantity and spatial distribution of emissions to air in the form of an atmospheric emission inventory database. In the case of traffic pollution, such an inventory must be compiled using activity statistics and emission factors for vehicle types. The majority of inventories are compiled using passive data from either surveys or transportation models and by their very nature tend to be out-of-date by the time they are compiled. The study of current trends are towards integrating urban traffic control systems and assessments of the environmental effects of motor vehicles. In this study, a methodology of motor vehicle emission calculation by using real-time traffic data was studied. A methodology for estimating emissions of CO at a test area in Seoul. Traffic data, which are required on a street-by-street basis, is obtained from induction loops of traffic control system. It was calculated speed-related mass of CO emission from traffic tail pipe of data from traffic system, and parameters are considered, volume, composition, average velocity, link length. And, the result was compared with that of a method of emission calculation by VKT(Vehicle Kilometer Travelled) of vehicles of category.

• Journal of the Institute of Convergence Signal Processing
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• v.3 no.3
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• pp.27-35
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• 2002

A knowledge-based image retrieval technique is image searching methods using some features from the queried image. The materials in this study are automobile head lamps. The input data is composed of characters and images which have various pattern. The numbers, special symbols, and general letters are under the category of the character. The image informations are made up of the distribution of pixel data, statistical analysis, and state of pattern which are useful for the knowledge data. In this paper, we implemented a retrieval system for the scientific crime detection at traffic accident using the proposed multi knowledge-based image retrieval technique. The values for the multi knowledge-based image features were extracted from color and gray scale each. With this 22 features, we improved the retrieval efficiency about the color information and pattern information. Visual basic, crystal report and MS access DB were used for this application. We anticipate the efficient scientific detection for the traffic accident and the tracking of suspicious vehicle.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.3
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• pp.341-347
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• 2007

For the purpose of finding how aircraft noise annoyance response is affected by variables when noise survey is performed, the questionnaire survey is conducted around the Gimpo International Airport in Seoul, Republic of Korea. This residential area is exposed to the aircraft noise and road traffic noise, simultaneously. Research areas are classified according to three different aircraft noise exposure levels expressed in WECPNL, under 75, between 75 and 80, and above 80 WECPNL, on aircraft noise map. The 7-step numerical magnitude with verbal category scales is used to measure the annoyance level. This survey suggests that aircraft noise annoyance is not affected to an important extent by other noise sources(road traffic noise, community noise) and demographic variables(sex, age, education, occupation, dwelling type, length of residence).

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.131-137
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• 2010

UMSN (Ubiquitous Medical Sensor Network) is being used in u-Healthcare system of various medical facilities to identify objects and get information from sensors in real-time. RFID using radio frequency determines objects using Reader, which reads Tags attached to patients. However, there is a security vulnerability wherein Tag send its ID to illegal Reader because Tags always response to Readers request regarding of its Tag ID. In this paper, we propose Tag ID Classification Scheme to reduce Back-end Server traffic that caused by requests to authenticate between Readers and Tags that are attached to medical devices, patients, and sensors; To reduce security threats like eavesdropping and spoofing that sometimes occurred during authentication procedure. The proposed scheme specifies the patient category as a group based on patients Tag ID string. Only allowed Reader can perform authentication procedure with Back-end Server. As a result, we can reduce Back-end Server traffic and security threats.

• Journal of Korean Society of Steel Construction
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• v.19 no.2
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• pp.211-221
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• 2007

A structural reliability analysis of fatigue truck model for fatigue failure of highway steel bridges was performed by applying the Miner's fatigue damage rule expressed as a function of various random variables affecting fatigue damage. Among the variables, the statistical parameters for equivalent moment, impact factor, and loadometer were obtained by analyzing recently measured domestic traffic data, whereas the parameters on fatigue strength, girder distribution factor, and headway factor of the measured data available in the literature were used. The effects of various fatigue truck models, fatigue life, ADTT, fatigue detail category, loadometer, and gross vehicle weight of fatigue truck on the reliability index of fatigue damage were analyzed. It is expected that the analytical results presented herein can be used as a basic background material in the calibration of both fatigue design truck and fatigue load factor of LRFD specification.

• Ecology and Resilient Infrastructure
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• v.7 no.4
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• pp.256-261
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• 2020

Roadside non-point pollution reduction facilities are classified as infiltration, vegetation, reservoir, and wetland types based on their respective pollution reduction mechanisms. However, without a detailed analysis of the road and traffic conditions it is very difficult for civil engineers to determine which category of pollution reduction facility is best suited to their planning requirements. To address this issue, we propose a new decision-making method for the selection of roadside non-point pollution reduction facilities. The principal factors informing the proposed decision-making methods are the road characteristics, including location, structure, number of lanes, and traffic volume. As a result of the study, a total of new pollution reduction plans were developed, with their selection conditions and the corresponding applicable facilities established. The effectiveness of the proposed pollution reduction schemes was demonstrated for roads in Kyounggi-do, providing a valuable basis for future pollution reduction plans.

• Korean Journal of Construction Engineering and Management
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• v.13 no.6
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• pp.13-23
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• 2012

While Category 1 and Category 2 bridges are intensively inspected and carefully managed, many small bridges that are not in the Category 1 and 2 are often forgotten until they decay in serious condition. Since many of these small bridges located in the populated city, failure of them would cause huge negative impact on the community. This paper focuses on the small size concrete bridges for timely repair and rehabilitation work for the effective operation and management. Test bed is developed to define the key parameters to forecast the long term performance of the bridges, mostly concrete box bridges. Key parameters suggested in this paper are cumulative fatigue due to repetitive heavy traffic loads and the acid attacks for concrete material deterioration. The cumulative fatigue is measured by the use of the mileage concept. For the long term data collection and inspection, stable and easy to use data collection system is installed as a test bed. The contribution of this research work is on the development of the test bed to define the key parameters of bridge deterioration.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2011.04a
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• pp.261-266
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• 2011

The purpose of this study was to identify the perception of residents on green home and their green residential life. For this study, a questionnaire survey was conducted and the items consisted of whether green home was perceived and how well green residential life was maintained in 6 types of environments. A total 118 responses of residents living in apartments of Seoul Metropolitan Area were used for data analysis. Using statistical program SPSS Win 18.0, frequency analysis, t-test, One-way ANOVA, and factor analysis was employed. The major findings were as follows: 1) slightly more than half of the respondents were aware of green home, and the vast majority were in favor of the green home policy; 2) most of the respondents carried out guidelines of green residential life, and in particular, green living on air environment was well done, followed by consumption, waste, energy, traffic and water; 3) the six kinds of environments were subcategorized by using factor analysis, and 3 to 5 factors were included in each category of environment. Also, it was found that age, educational level, employment status of respondents, housing tenure and duration were related to the degree of green residential life. In midst of global movement toward sustainability, environmentally friendly living is not optional but mandatory, so it's important to change each individual's value on the relation between people and environment and to facilitate more environmentally conscious behaviors.