• Journal of Communications and Networks
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• v.14 no.3
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• pp.310-318
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• 2012

Detecting intrusion attacks accurately and rapidly in wireless networks is one of the most challenging security problems. Intrusion attacks of various types can be detected by the change in traffic flow that they induce. Wireless industrial networks based on the wireless networks for industrial automation-process automation (WIA-PA) standard use a superframe to schedule network communications. We propose an intrusion detection system for WIA-PA networks. After modeling and analyzing traffic flow data by time-sequence techniques, we propose a data traffic prediction model based on autoregressive moving average (ARMA) using the time series data. The model can quickly and precisely predict network traffic. We initialized the model with data traffic measurements taken by a 16-channel analyzer. Test results show that our scheme can effectively detect intrusion attacks, improve the overall network performance, and prolong the network lifetime.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.5 no.1
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• pp.83-87
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• 1980

The distributive processing job in a hierarchical computer network, which supervises and controls the complex relations between the variables periodically for raising the fault folerance, can be defined its periodicity and its execution time. All the job may be composed of the subsets in relation of Tree structure. For a processor job set this paper finds out a job scheduling algorithm that has the less loose time between period than that of FCFS.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.406-409
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• 2001

This study refers to development of WBS(Work Breakdown Structure) and Activity sample for integrated cost and schedule control system of sample bridge work in the field. The conclusions from this study may be summarized as following 1. It showed that the level of detail to network's activities depend upon schedule's intended purpose. 2. It is more effective 'activity to cost package model' than 'activity to resource model', for integrated cost and schedule control reflect the characteristics of domestic construction industry.

• International Journal of Precision Engineering and Manufacturing
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• v.1 no.2
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• pp.5-13
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• 2000

Most networks for automation are tuned to an expected traffic condition ar their design stage. During their actual operations, however, the networks experience considerable changes in traffic from time to time. These traffic changes caused by common events like machine failure and production schedule change may adversely affect th network performance and, in turn , the performance of the connected devices. This paper presents experimental results for performance management of a Profibus-FMS network. The performance management aims to maintain a uniform level of network performance at all stations under changing network traffic. The performance management algorithm monitors the performance of individual network stations and commands the stations to change their timer values in order to have comparable performance at all stations. In order to determine the amount of timer change, the algorithm employs a set of fuzzy rules. The algorithm has been evaluated on a Profibus network.

• Korean Journal of Cognitive Science
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• v.19 no.3
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• pp.297-310
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• 2008

Since speech acts implies speakers' intentions, it is essential to determine speakers' speech acts if we want to implement an intelligent dialogue system. We propose a two-step model for effectively determining speakers' speech acts. In the first step, the proposed model returns speech act candidates by using a neural network model based on machine learning and a predictivity model based on statistics, respectively. In the second step, using speech act candidates which are returned by the predictivity model, the proposed model filters out speech act candidates which are returned by the neural network model. Then, the proposed model selects a speech act with maximum output value among the unremoved speech act candidates. In the experiment on a schedule management domain, the proposed two-step modeling method showed better precisions than the previous methods only using a machine learning model or a probability model.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.3
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• pp.499-510
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• 2012

An SNS(Social Network Service) is an online service that supports an effective way to share information over virtual communities. Recently, as SNSs such as Twitter, Facebook, and Me2day are getting bigger, the purposes of using popular SNSs are expanded to broadcastings, politics, marketings and so on. In this paper, we propose an API to integrate and manage open APIs for various SNSs, presenting a library as an implementation of the proposed API. Also, utilizing the developed library, a smartphone application is provided which supports integrated management of popular SNSs and personal schedules. Using the library, developers can reduce costs when they need to implement specific functions for managing various SNSs. With the developed application, we can read and write to/from the related SNSs on same screen, automatically reminding our schedule and sharing the schedule with friends over the SNSs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.5
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• pp.949-966
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• 2013

Recently, Wireless Body Area Network (WBAN) has promise to revolutionize human daily life. The need for multiple sensors and constant monitoring lead these systems to be energy hungry and expensive with short operating lifetimes. In this paper, we offer a review of existing work of WBAN and focus on energy-aware management in it. We emphasize that nodes computation, wireless communication, topology deployment and energy scavenging are main domains for making a long-lived WBAN. We study the popular power management technique Dynamic Voltage and Frequency Scaling (DVFS) and identify the impact of slack time in Dynamic Power Management (DPM), and finally propose an enhanced dynamic power management method to schedule scaled jobs at slack time with the goal of saving energy and keeping system reliability. Theoretical and experimental evaluations exhibit the effectiveness and efficiency of the proposed method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.470-473
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• 2002

Most networks for automation are tuned to an expected traffic at their design stage. During their actual operations, however, the networks experience considerable changes in traffic from time to time. These traffic changes caused by common events like machine failure and production schedule change may adversely affect the network performance and, in turn, the performance of the connected devices. This paper presents communication delay model for Profibus token passing protocol, and introduces TTR selection methods to maintain a uniform level of network performance at all stations under changing network traffic.

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.1
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• pp.3-16
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• 1995

JIT manufacturing requires that materials and services should be done neither too early nor tardy. Therefore, related jobs have to be performed just-in-time. In this paper, we consider a problem of determining a schedule of jobs with a common due date. The objective is to minimize the squared deviation of complete times from the due date. An artificial neural network which is based on the mean field theory is proposed for the problem. Computational results obtained from computer simulations show that the network performs very well.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.10
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• pp.720-726
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• 2004

The data transmission over MVB(Multifunction Vehicle Bus) of TCN(Train Communication Network) is divided into the periodic transmission phase and the sporadic transmission phase. TCN standard recommends the event-polling method as the message transfer in the sporadic phase. However, since the event-polling method does not use pre-scheduling to the priority of the messages, it is inefficient for the real-time systems. To schedule message transmission, a master node should know the priority of message to be transmitted by a slave node prior to the sporadic phase, but the existing TCN standard does not support any protocol for this. This paper proposes the slave frame bit-stuffing algorithm, with which a master node gets the necessary information for scheduling and includes the simulation results of the event-polling method and the proposed algorithm.