• Journal of Power System Engineering
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• v.10 no.2
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• pp.93-98
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• 2006

Metal matrix composites(MMCs) reinforced with ceramic particulates are receiving increasing attention because their high specific strength, low coefficient of thermal expansion and excellent wear resistance. Especially, Al-based composites(AMCs) have been widely applied for the aerospace and automotive industries. Such composites are mainly fabricated by the cast, powder metallurgy and infiltration process. In this study, SiC particulate reinforced Al-based composites were fabricated by thermal spray process and their wear behavior were investigated. Composites with different spray parameter were fabricated by using flame spray apparatus. Microstructure and wear behavior of the composites were observed by scanning electron microscope(SEM) and electron probe micro-analysis(EPMA).

• International conference on construction engineering and project management
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• 2015.10a
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• pp.10-14
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• 2015

Unsafe behavior is one of the major causes of construction accidents. Managing the behavior of workers in real-time is difficult and requires huge manpower. In this paper, a new real-time locating framework is proposed to improve safety management by collecting and analyzing data describing the behavior of workers to identify habits that may lead to accidents. The aim of the study is to identify working habits of workers based on their location history. Location data is used to compare with that of other workers and equipment. The results indicate that the reuse of real-time location data can provide extra safety information for safety management and that the proposed system has the potential to prevent struck-by accidents and caught-in between accidents by predicting unwanted interaction between workers and equipment. This adds to current research aimed at automating construction safety to the point where the continuous monitoring, managing and protection of site workers on site is possible.

• Smart Structures and Systems
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• v.20 no.5
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• pp.563-572
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• 2017

The safety of structures is closely associated with the structural out-of-plane behavior. In particular, long and slender beam structures have been increasingly used in the design and construction. Therefore, an evaluation of the lateral and torsional behavior of a structure is important for the safety of the structure during construction as well as under service conditions. The current contact measurement method using displacement meters cannot measure independent movements directly and also requires caution when installing the displacement meters. Therefore, in this study, a vision-based system was used to measure the in-plane and out-of-plane displacements of a structure. The image processing algorithm was based on reference objects, including multiple targets in Lab color space. The captured targets were synchronized using a load indicator connected wirelessly to a data logger system in the server. A laboratory beam test was carried out to compare the displacements and rotation obtained from the proposed vision-based measurement system with those from the current measurement method using string potentiometers. The test results showed that the proposed vision-based measurement system could be applied successfully and easily to evaluating both the in-plane and out-of-plane movements of a beam including twisting rotation.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.6
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• pp.48-55
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• 2005

In this paper, a mathematical model and a simulation method for the response time analysis of Local Interconnect Network(LIN) based network systems are proposed. Network-induced delays in a network based control system can vary widely according to the transmission time of message and the overhead time of transmission. Therefore, in order to design a distributed control system using LIN network, a method to predict and verify the timing behavior of LIN protocol is required at the network design phase. Furthermore, a simulation environment based on a timing model of LIN protocol is beneficial to predict the timing behavior of LIN. The model equation is formulated with six timing parameters deduced from timing properties of LIN specification. Additionally, LIN conformance test equations to verify LIN device driver are derived with timing constraints of the parameters. The proposed model equation and simulation method are validated with a result that is measured at real LIN based network system.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1159-1166
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• 2017

Cattle behavior detection system based on Internet of Things is designed and implemented by using gyroscope and acceleration sensor, Arduino pro-mini and bluetooth module. The implemented system measures cattle's moving and the measured data are transmitted to smart phone by bluetooth module. They are displayed by 2-dimensional graph on the smart phone and the number of cattle's step are calculated from the graph. The detected and gathered data from the system are analyzed by the proposed algorithm to decide which cows are in the estrus or not, and the proposed system can be used to increase the success rate of artificial insemination in normal estrus by detecting cow's behaviors such as the number of steps and jumping. In this paper, the implemented cattle behavior detecting system are strapped on cattle's leg and it measures cattle behaviors for determining that a cattle is estrus or not by the proposed algorithm. In the future research, the system which lengthens communication distance and increases the number of cattle under the test will be considered and also the measured data will be database for cattle research.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.10
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• pp.1731-1737
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• 2007

The Korea electricity wholesale market is operated under the cost-based-pool system and the government regulation to the new generation capacities in order to insure the resource adequacy. The goal of government's regulation is the electricity market stability by attracting proper generation investment while keeping the reliability of system. Generation companies must mandatory observe that government plan by now. But if the restructuring is to be complete, generation companies should not bear any obligation to invest unless their profitability is guaranteed. Namely the investors' behavior will be affected by the market prices. In this paper, the system dynamics model for Korea wholesale electricity market to examine whether competitive market can help to stabilize is developed and analyzes the investors behavior. The simulation results show that market controlled by government will be operated stable without resulting in price spike but there is no lower price because of maintaining the reasonable reserve margin. However, if the competition is introduced and the new investment is determined by the investor's decision without government intervention, the benefits from lower wholesale price are expected. Nevertheless, the volatility in the wholesale market increases, which increases the investment risks.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4553-4562
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• 2010

With developing networks, information security is going to be important and therefore lots of intrusion detection system has been developed. Intrusion detection system has abilities to detect abnormal behavior and unknown intrusions also it can detect intrusions by using patterns studied from various penetration methods. Various algorithms are studying now such as the statistical method for detecting abnormal behavior, extracting abnormal behavior, and developing patterns that can be expected. Etc. This study using clustering of data mining and association rule analyzes detecting areas based on two models and helps design detection system which detecting abnormal behavior, unknown attack, misuse attack in a large network.

• Journal of the Korean Society for information Management
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• v.21 no.2
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• pp.211-233
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• 2004

The web is a new information environment, which has different characteristics from a traditional IR environment. Needed are more research from a new point of view as well as the adoption of a new research paradigm in order to understand a user-system interaction on the web. The purpose of this study is to review and analyze models of web-based information seeking behavior, which Wang, Hawk ＆ Tenopir, Hsieh-Yee, Choo, Detlor ＆ Turnbull, Chun ＆ Cooper, Rieh, and Spink proposed. The comparative analysis indicates that web-based information seeking models are categorized into three area: interaction model, information seeking behavior model, and evaluation model, and that they are based on a multifaceted interaction and a nonlinear perspective.

• The KIPS Transactions:PartC
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• v.10C no.4
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• pp.397-404
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• 2003

Intrusion detection techniques based on program behavior can detect potential intrusions against systems by analyzing system calls made by demon programs or root-privileged programs and building program profiles. But there is a drawback : large profiles must be built for each program. In this paper, we apply $X^2$ distance-based multivariate analysis to profiling program behavior and detecting abnormal behavior in order to reduce profiles. Experiment results show that profiles are relatively small and the detection rate is significant.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.4
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• pp.29-34
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• 2010

As the nature of the embedded system, it is operated by user specified requirements, the dynamic action(behavior) is needed when the user's requirements change or unexpected situations occur. In this paper, it is proposed that design and implementation of SOA(Service-oriented architecture) based S/W services for dynamic behavior of embedded System. In this proposed technique, the status of embedded system can be checked through Web services, and in the cases of exceptional situations, the required proper actions can be newly updated through Web services. Through this technique, the burden of users concerning exceptional situations can be reduced, and the convenience of use can increased as well.