• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2484-2496
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• 2000

High speed switches have been developing to interconnect a large number of nodes. It is important to analyze the switch performance under various conditions to satisfy the requirements. Queueing analysis, in general, has the intrinsic problem of large state space dimension and complex computation. In fact, The petri net is a graphical and mathematical model. It is suitable for various applications, in particular, manufacturing systems. It can deal with parallelism, concurrence, deadlock avoidance, and asynchronism. Currently it has been applied to the performance of computer networks and protocol verifications. This paper presents a framework for modeling and analyzing ATM switch using stochastic activity networks (SANs). In this paper, we provide the ATM switch model using SANs to extend easily and an approximate analysis method to apply A TM switch models, which significantly reduce the complexity of the model solution. Cell arrival process in output-buffered Queueing A TM switch with finite buffer is modeled as Markov Modulated Poisson Process (MMPP), which is able to accurately represent real traffic and capture the characteristics of bursty traffic. We analyze the performance of the switch in terms of cell-loss ratio (CLR), mean Queue length and mean delay time. We show that the SAN model is very useful in A TM switch model in that the gates have the capability of implementing of scheduling algorithm.

• Journal of Korea Water Resources Association
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• v.31 no.1
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• pp.35-44
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• 1998

An integrated system of GIS and water quality model was suggested including the pollutant loads from the watershed. The developed system consists of two parts. First part is the GIS module. The geographic information system of the study area was built to provide the information on landuse and several surface factors concerning the overland flow processes of water and pollutants. Second part is the modeling modules which include storm event pollutant load model(SEPLM)., non-storm event pollutant load model(NSPLM), and river water quality simulation model(RWQSM). Models can calculate the pollutant load from the study area. The databases and models are linked through the interface modules resided in the overall system, which incorporate the graphical display modules and the operating scheme for the optimal use of the system. The developed system was applied to the Chungju multi-purpose reservoir to estimate the pollutant load during the four selected rainfall events between 1991 and 1993,. based upon monthly basis and seasonal basis in drought flow, low flow, normal flow and wet flow.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.3
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• pp.47-65
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• 2014

VMS(Variable Message Sign) helps drivers to choose their path to destinations on roadways. Some types of VMS often provide traffic information with clearly visible and comprehensible graphical route diagrams. Currently many diagramed types of VMS are installed on urban arterial and highways. This type of VMS surely enhances drivers' ability to comprehend traffic route information while they are driving on the roadway. Nevertheless, some of them are presented with so much information and design elements and they sometimes lead to decline of drivers' comprehensible level for traffic information. Drivers would fail to decide their preferable route in this state of information overflow. The purpose of this paper is to develop a drivers preference model for effective design principle including size and height of displaying font, and the amount of information in the route diagram considering driving speed, sex and age of the driver. This model is developed using structural equation modeling techniques. This model considers driver's emotional factor and, human factor and design component of route diagram. To collect data, we built driving simulator which is able to replicate real driving condition. 72 people who participated in the simulation were selected considering gender and age. The developed model showed that the amount of information, and visibility are more influential factors to the drivers' preference of the route diagram on VMS than design elements such as the shape and the font of the diagram.

• Archives of design research
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• v.17 no.3
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• pp.133-146
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• 2004

Diagrams have been deeply and widely used for supporting effective communication relating to design information and knowledge in most design fields. The results show that their role expands to "developmental design material" increasing the principle and method of design process. It's recent trend that Digital-Diagrams are aggressively used in multimedia design fields such as web contents, interactive movies and DVD Titles in order to support user's information understanding more effectively and to stimulate user's participation in information acquiring process. This study aims to clarify the essence of digital diagram corresponding to infographic material in multimedia design and application of multimedia contents development process . This study purpose leads to argue the substance of Digital-Diagrams as one of infographic types and identity of Digital-Diagrams which is relatively compared to existing Diagrams. Eventually, this study examines the application issues of Digital-Diagrams in multimedia design process. Regarding the identity of Digital-Diagrams, they are functionally utilized depending on hypertext based on language forms and interactivity based on graphical forms as core attributes. Therefore, they semantically enlarge user s information understanding by segmenting hierarchy of information expression and rather support user s acquisition of information control ability. Relating to multimedia design process, Digital-Diagrams are used by information designers and navigation designers as method for ‘modeling for realization based on information acquisition support for information-users. Especially, the study results show that the applications of Digital-Diagrams are performed for information representing methods for information designers and embodiment of useful functional factors of interface for navigation designersgation designers.

• International Journal of Computer Science & Network Security
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• v.21 no.3
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• pp.257-265
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• 2021

Modern methods of regulating migration processes in EU states include a wide variety of adapted, transformed under the sway of globalization tools in order to influence the movement of human capital within the European space. The main purpose of the regulatory policy on migration flows is the redistribution of professionally competent professionals between different spheres of life. Herewith, the determining factor in the effectiveness of such distribution is a rational combination of stimulating and disincentive levers of influence on the movement of citizens of different EU countries and taking into account the motives of such mobility. Modernization of migration management approaches can be a major economic, social, political and cultural progress of European countries. The purpose of the research is to conduct a detailed analysis of existing practices of migration flow management, in particular their stimulation or containment, and to outline key migration trends formed under the influence of multicomponent approaches to migration regulation, transformation of regulatory legislation and changing priorities of modern society. The research methods: statistical-analytical method; ARIS method; method of tabular, graphical and analytical modeling; comparative analysis; systematization, generalization. Results. Current pan-European methods of regulating migration processes are insufficiently adapted to the multinational socialeconomic space; consequently, there are some disparities in the distribution of migrants between EU countries, although the overall dynamics of migration is positive. Fluctuations in the population of European countries during 2000-2019 and trends in the transformation of social-economic space confirm the insufficient level of influence of current methods of regulating migration flows. Along with this, the presence of a characteristic asymmetry in the distribution of migrants requires a greater focus on the modernization of regulatory instruments, in particular, the regulatory mechanism for managing migration processes. As a result of the conducted study, further prospects for the implementation of alternative methods of regulating migration processes in EU states have been outlined; the current and projected limits for increasing the level of observance of migrants' rights at the European level have been clarified through the adoption of appropriate regulatory acts; effective solutions for intensifying the influx of high-quality labor resources from different countries to EU have been identified. The research results can be used to study methods of regulating migration processes in the countries in the global dimension.

• Journal of Intelligence and Information Systems
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• v.20 no.2
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• pp.109-122
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• 2014

People are nowadays creating a tremendous amount of data on Social Network Service (SNS). In particular, the incorporation of SNS into mobile devices has resulted in massive amounts of data generation, thereby greatly influencing society. This is an unmatched phenomenon in history, and now we live in the Age of Big Data. SNS Data is defined as a condition of Big Data where the amount of data (volume), data input and output speeds (velocity), and the variety of data types (variety) are satisfied. If someone intends to discover the trend of an issue in SNS Big Data, this information can be used as a new important source for the creation of new values because this information covers the whole of society. In this study, a Twitter Issue Tracking System (TITS) is designed and established to meet the needs of analyzing SNS Big Data. TITS extracts issues from Twitter texts and visualizes them on the web. The proposed system provides the following four functions: (1) Provide the topic keyword set that corresponds to daily ranking; (2) Visualize the daily time series graph of a topic for the duration of a month; (3) Provide the importance of a topic through a treemap based on the score system and frequency; (4) Visualize the daily time-series graph of keywords by searching the keyword; The present study analyzes the Big Data generated by SNS in real time. SNS Big Data analysis requires various natural language processing techniques, including the removal of stop words, and noun extraction for processing various unrefined forms of unstructured data. In addition, such analysis requires the latest big data technology to process rapidly a large amount of real-time data, such as the Hadoop distributed system or NoSQL, which is an alternative to relational database. We built TITS based on Hadoop to optimize the processing of big data because Hadoop is designed to scale up from single node computing to thousands of machines. Furthermore, we use MongoDB, which is classified as a NoSQL database. In addition, MongoDB is an open source platform, document-oriented database that provides high performance, high availability, and automatic scaling. Unlike existing relational database, there are no schema or tables with MongoDB, and its most important goal is that of data accessibility and data processing performance. In the Age of Big Data, the visualization of Big Data is more attractive to the Big Data community because it helps analysts to examine such data easily and clearly. Therefore, TITS uses the d3.js library as a visualization tool. This library is designed for the purpose of creating Data Driven Documents that bind document object model (DOM) and any data; the interaction between data is easy and useful for managing real-time data stream with smooth animation. In addition, TITS uses a bootstrap made of pre-configured plug-in style sheets and JavaScript libraries to build a web system. The TITS Graphical User Interface (GUI) is designed using these libraries, and it is capable of detecting issues on Twitter in an easy and intuitive manner. The proposed work demonstrates the superiority of our issue detection techniques by matching detected issues with corresponding online news articles. The contributions of the present study are threefold. First, we suggest an alternative approach to real-time big data analysis, which has become an extremely important issue. Second, we apply a topic modeling technique that is used in various research areas, including Library and Information Science (LIS). Based on this, we can confirm the utility of storytelling and time series analysis. Third, we develop a web-based system, and make the system available for the real-time discovery of topics. The present study conducted experiments with nearly 150 million tweets in Korea during March 2013.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.10
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• pp.1905-1919
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• 2000

The main motivation of this research is to develop an intelligent control strategy for Activated Sludge Process (ASP). ASP is a complex and nonlinear dynamic system because of the characteristic of wastewater, the change in influent flow rate, weather conditions, and etc. The mathematical model of ASP also includes uncertainties which are ignored or not considered by process engineer or controller designer. The ASP is generally controlled by a PID controller that consists of fixed proportional, integral, and derivative gain values. The PID gains are adjusted by the expert who has much experience in the ASP. The ASP model based on $Matlab^{(R)}5.3/Simulink^{(R)}3.0$ is developed in this paper. The performance of the model is tested by IWA(International Water Association) and COST(European Cooperation in the field of Scientific and Technical Research) data that include steady-state results during 14 days. The advantage of the developed model is that the user can easily modify or change the controller by the help of the graphical user interface. The ASP model as a typical nonlinear system can be used to simulate and test the proposed controller for an educational purpose. Various control methods are applied to the ASP model and the control results are compared to apply the proposed intelligent control strategy to a real ASP. Three control methods are designed and tested: conventional PID controller, fuzzy logic control approach to modify setpoints, and fuzzy-PID control method. The proposed setpoints changer based on the fuzzy logic shows a better performance and robustness under disturbances. The objective function can be defined and included in the proposed control strategy to improve the effluent water quality and to reduce the operating cost in a real ASP.