• The Journal of the Korea Contents Association
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• v.6 no.7
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• pp.58-68
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• 2006

There are two traditional scheduling methods known as PQ and WRR in the DiffServ network, however, these two scheduling methods have some drawbacks. In this paper, we propose an algorithm that can be adopted in WRR scheduler with making up for weak points of PQ and WRR. The proposed algorithm produces the control discipline by the fuzzy theory to dynamically assign the weight of WRR scheduler with checking the Queue status of each class. To evaluate the performance of the proposed algorithm, We accomplished a computer simulation using NS-2. From simulation results, the proposed algorithm improves the packet loss rate of the EF class traffic to 6.5% by comparison with WRR scheduling method and that of the AF4 class traffic to 45% by comparison with PQ scheduling method.

• Journal of Internet Computing and Services
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• v.6 no.1
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• pp.105-114
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• 2005

This paper describes a new measuring technique by analysing multiple time-series patterns. This paper's goal is that extracts a really measured value having a sample pattern which is the best matched with an inputted time-series, and calculates a difference ratio with the value. Therefore, the proposed technique is not a recognition but a measurement. and not a hardware but a software. The proposed technique is consisted of three stages, initialization, learning and measurement. In the initialization stage, it decides weights of all parameters using importance given by an operator. In the learning stage, it classifies sample patterns using LBG and DTW algorithm, and then creates code sequences for all the patterns. In the measurement stage, it creates a code sequence for an inputted time-series pattern, finds samples having the same code sequence by hashing, and then selects the best matched sample. Finally it outputs the really measured value with the sample and the difference ratio. For the purpose of performance evaluation, we tested on multiple time-series patterns obtained from etching machine which is a semiconductor manufacturing.

• Journal of Korea Multimedia Society
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• v.14 no.1
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• pp.24-32
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• 2011

In ubiquitous environment, the analysis for student's learning behaviour is essential to provide students with personalized education. SCORM(Sharable Contents Object Reference Model), IMS LD (Instructional Management System Learning Design) standards provide the support function of learning design such as checking the progress. However, in case of applying these standards contain many problem to add or modify the contents. In this paper, We implement the system that manages the learner behaviour by hooking the event of web browser. Through all of this, HTML-based content can be recycled without any additional works and the problems by applying the standard can be improved because the store and analysis of the learning result is possible. It also supports the ubiquitous learning environment because of keeping track of the learning result in case of network disconnected.

• Journal of Korea Multimedia Society
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• v.11 no.3
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• pp.301-314
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• 2008

The existing event recognition is accomplished with the limited systematic foundation, and thus much longer learning time is needed for emergency scenario interpretation due to large scale of probability data. In this paper, we propose a method for nile-based event recognition of an independent object(human) which extract a feature vectors from the object and analyze the behavior pattern of each object and interpretation of emergency scenarios using a probability and object's events. The event rule of an independent object is composed of the Primary-event, Move-event, Interaction-event, and 'FALL DOWN' event and is defined through feature vectors of the object and the segmented motion orientated vector (SMOV) in which the dynamic Bayesian network is applied. The emergency scenario is analyzed using current state of an event and its post probability. In this paper, we define diversified events compared to that of pre-existing method and thus make it easy to expand by increasing independence of each events. Accordingly, semantics information, which is impossible to be gained through an.

• The KIPS Transactions:PartC
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• v.15C no.6
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• pp.531-538
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• 2008

With the dynamic and mobile nature of ad hoc networks, links may fail due to topology changes. So, a major challenge in ad hoc network is dynamically to search paths from a source to destination with an efficient routing method, which is an important issue for delay-sensitive real-time application. The main concerns of graph theory in communications are finding connectivity and searching paths using given nodes. A topology of the nodes in ad hoc networks can be modeled as an adjacency matrix. In this paper, based on this adjacency matrix, we propose new path search algorithms using a sequence of matrix calculation. The proposed algorithms can search paths from a destination to a source using connectivity matrix. Two matrix-based algorithms for two different purposes are proposed. Matrix-Based Backward Path Search(MBBS) algorithm is designed for shortest path discovery and Matrix-Based Backward Multipath Search(MBBMS) algorithm is for multipath search.

• Journal of KIISE:Software and Applications
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• v.31 no.11
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• pp.1483-1495
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• 2004

Recently, new computing technologies are emerging from various life environments, as a result of the spread of network environments and the advent of new computing devices. This trend in computing technology is called "Ubiquitous computing" and is being developed to provide a convenient lifestyle through the dynamic integration of physical objects and digital information. The hybrid tag interface suggested in this paper is a usage model that integrates widely used image codes and recently applied RFIDs in various applications. On the basis of this concept, we eventually designed five different models such as Dual, Partial, Relative, Rebind and Discrete types according to their interrelation. In this paper, the characteristics of tag interfaces in the form of image codes and RFIDs are analyzed and the hybrid tag interface is proposed here for more efficient and convenient interface.

• Journal of KIISE:Databases
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• v.33 no.3
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• pp.327-341
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• 2006

As we are getting to deal with more applications that generate streaming data such as sensor network, monitoring, and SDI (selective dissemination of information), active research is being conducted to support efficient processing of queries over streaming data. The applications on the Web environment like SDI, among others, require query processing over streaming XML data, and its investigation is very important because XML has been established as the standard for data exchange on the Web. One of the major problems with the previous systems that support query processing over streaming XML data is that they cannot deal adaptively with dynamically changing stream because they rely on static query plans. On the other hand, the stream query processing systems based on relational data model have achieved adaptiveness in query processing due to query operator routing. In this paper, we propose a system of adaptive query processing over streaming XML data in which the model of adaptive query processing over streaming relational data is applied. We compare our system with YFiiter, one of the representative systems that provide XML stream query processing capability, to show efficiency of our system.

• Journal of KIISE
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• v.42 no.3
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• pp.295-306
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• 2015

MOnCa2 is a framework for building intelligent smartphone applications based on smartphone sensors and ontology reasoning. In previous studies, MOnCa determined and inferred user situations based on sensor values represented by ontology instances. When this approach is applied, recognizing user space information or objects in user surroundings is possible, whereas determining the user's physical context (travel behavior, travel destination) is impossible. In this paper, MOnCa2 is used to build recognition models for travel behavior and routes using smartphone sensors to analyze the user's physical context, infer basic context regarding the user's travel behavior and routes by adapting these models, and generate high-level context by applying ontology reasoning to the basic context for creating intelligent applications. This paper is focused on approaches that are able to recognize the user's travel behavior using smartphone accelerometers, predict personal routes and destinations using GPS signals, and infer high-level context by applying realization.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.8
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• pp.46-55
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• 2002

A nonlinear aeroelastic analysis system in transonic and supersonic flows has been developed using high speed parallel processing technique on the network based PC-clustered machines. This paper includes the coupling of advanced numerical techniques such as computational structural dynamics (CSD), finite element method (FEM) and computational fluid dynamics (CFD). The unsteady Euler solver on dynamic unstructured meshes is employed and coupled with computational aeroelastic solvers. Thus it can give very accurate engineering data in the structural and aeroelastic design of flight vehicles. To show the great potential of useful application, transonic and supersonic flutter analyses have been conducted for a complete aircraft model under developing in Korea.

• Archives of design research
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• v.19 no.3 s.65
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• pp.93-104
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• 2006

When the design profession started, design targets were mainly static hardware centered products. Due to the development of network and digital technologies, new products with dynamic and software-hardware hybrid interactive characteristics have become one of the main design targets. To accomplish the new projects, designers are required to learn new methods, tools and theories in addition to the traditional design expertise of visual language. One of the most important tools for the change is effective and rapid prototyping. There have been few researches on educational framework for interactive product or system prototyping to date. This paper presents a new model of educational contents and methods for interactive digital product prototyping, and it's application in a design curricula. The new course contents, integrated with related topics such as physical computing and tangible user interface, include microprocessor programming, digital analogue input and output, multimedia authoring and programming language, sensors, communication with other external devices, computer vision, and movement control using motors. The final project of the course was accomplished by integrating all the exercises. Our educational experience showed that design students with little engineering background could learn various interactive digital technologies and its' implementation method in one semester course. At the end of the course, most of the students were able to construct prototypes that illustrate interactive digital product concepts. It was found that training for logical and analytical thinking is necessary in design education. The paper highlights the emerging contents in design education to cope with the new design paradigm. It also suggests an alterative to reflect the new requirements focused on interactive product or system design projects. The tools and methods suggested can also be beneficial to students, educators, and designers working in digital industries.