• Journal of Educational Research in Mathematics
• /
• v.15 no.4
• /
• pp.489-504
• /
• 2005

In this paper, we design a environment in computers and mathematics education. For this purpose, we study two different points of view about relations between computers and mathematics education. As theoretical background, we also study constructionism and microworld. Next, we introduce functionization as a basic principle for computers and mathematics education. The concept of functionization focuses on the variation of mathematical objects, and it is a basic concept of both mathematics and computer science. We consider the concept of functionization as a paradigm for the research and practice of the computers and mathematics education. We also present the concept of functionization as a principle for designing a computer environment. Finally, we use the concept of functionization to integrate two famous microworlds, LOGO and DGS by introducing such objects as tiles and folding nets. Combining LOGO and DGS, we design a new microworld that can be used under the internet environment. We present tiles and folding nets to introduce how the concept of functionization is used to design a new microworld and to integrate two microworids.

• The Pure and Applied Mathematics
• /
• v.12 no.1
• /
• pp.75-91
• /
• 2005

The main objective of this paper is to introduce the gradation of neigh-bourhoodness in L-fuzzy topology and to introduce the fuzziness in the concept of convergence of L-fuzzy nets.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.8 no.2
• /
• pp.177-184
• /
• 1988

The method of least squares has been applied to the static data, but it was not applications for the processing of observed values accompaning real-time variation. In this paper, having been considered all observations to be the function of time, leveling nets were analized dynamically by introducing the concept of time to conventional method of least squares. As a results, the method of dynamic least squares was well applicable to the adjustment of leveling nets.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.66-66
• /
• 2000

In this parer, we introduce an algorithm to control flows of the traffic in multi-intersections. It is pointed out that the main problem in traffic control is how to resolve the congested situations for the particular time-durations and directions. The heavy load to a certain direction usually leads the intersection to congested situations, and the adjacent intersections are affected. We control and analyze the traffic flow of multi-intersections consisting of five intersections, in which four intersections are linked to the four directions of the central one. The entrance of vehicles of each direction is described using the concept of probability. We compare the performance of the pretimed signal controls to the traffic adaptive signal controller using a Petri Net simulation tool, Exspect.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.2
• /
• pp.453-460
• /
• 2013

This study proposes a framework that enables efficient integration and usage of enterprise data using semantic based concept net. Integration of enterprise information that has been increasing geometrically in cloud environment. The concept net is very similar in approaching way to existing ontology. However, it builds correlation between object and concept to help user's information integration retrieval more efficiently. In this study, concept nets are divided into 3 kinds and are applied to the proposed framework independently. The concept net in this study is built in ontology format based on master information concept net, keyword concept net and business process concept net. This concept net enables retrieval and usage of data based on correlation among data according to user's request. Then, through combination of master information concept and keyword concept, it provides frequency trace of keyword and category thus improving convenience and speed of retrieval.

• Journal of the Korea Society for Simulation
• /
• v.25 no.4
• /
• pp.21-30
• /
• 2016

Recently manufacturing companies have used PLC control programs popularly for their automated production systems. Since the life cycle of production process is not so long, the change of the production lines occur frequently. Most of changes happen with modification of the position information and control process of the equipment. PLC control program is also modified based on the fundamental process. Therefore, to verify new PLC program by configuring virtual space according to real environment is needed. In this paper we show a logical modeling method, based on Timed-FSA useful for sequence control and dead-lock prevention. There is a problem wasting user's labor and time when defining a variety of states in a device. To overcome this problem, we propose an extended I-O model based on existing methods by adding a token concept of Petri Nets. Also we will show the usability of the extended I-O modeling through user study.

• The Journal of Society for e-Business Studies
• /
• v.13 no.3
• /
• pp.67-83
• /
• 2008

Web caching server is one of the important components of any web site, as it makes the access of users to web content much faster while balancing the network and server load. There are many caching approaches proposed in order to solve this problem. Classically, we know several caching algorithms like FIFO, LRU, LRU-min and etc. Most of them have their advantages and disadvantages based on specific context. The purpose of this paper is to introduce the new concept of caching objects along with their related content and test the performance of the proposed caching method using CPN Tools simulator program. It is generally known that the use of Colored Petri Nets(CPNs) for modeling the simulation of new idea is one of the popular methods of system evaluation throughout software development projects. Moreover it could be very handy in describing the overall logic of the system. The CPN Tools is one of the most robust simulator programs which supports all necessary tools and functions to build and run the simulation model for CPN. Therefore in this paper, we will use CPN Tools software in order to build a simulator for our innovative caching approach named as web caching with related content. Then we will analyze the results derived from the simulation of our model and will make corresponding conclusions.

• Journal of Internet Computing and Services
• /
• v.22 no.5
• /
• pp.9-16
• /
• 2021

Recently, the traffic volume of mobile communications increases rapidly and the small-cell is one of the solutions using two offload schemes, i.e., local IP access (LIPA) and selected IP traffic offload (SIPTO), to reduce the end-to-end delay and amount of mobile data traffic in the core network (CN). However, 3GPP describes the concept of LIPA and SIPTO and there is no decision algorithm to decide the path from source nodes (SNs) to destination nodes (DNs). Therefore, this paper proposes a dynamic mobile data traffic offload scheme using small-cells to decide the path based on the SN and DN, i.e., macro user equipment, small-cell user equipment (SUE), and multimedia server, and type of the mobile data traffic for the real-time and non-real-time. Through analytical models, it is shown that the proposed offload scheme outperforms the conventional small-cell network in terms of the delay of end-to-end mobile data communications and probability of the mobile data traffic in the CN for the heterogeneous networks.

• Journal of Korean Institute of Industrial Engineers
• /
• v.25 no.1
• /
• pp.87-99
• /
• 1999

A shop floor control system(SFCS) performs the production activities required to fill orders. In order to effectively control these activities, the autonomous agent-based heterarchical shop floor control architecture is adopted where a supervisor does not exist. In this paper, we define functional perspective of the heterarchical shop floor control using planning, scheduling, and execution modules. In particular, we focus on an execution module that can coordinate the planning and scheduling modules and a general execution module that easily can be modified to execute the other equipment. The execution module can be defined informally as a module that downloads and performs a set of scheduled tasks. The execution module is also responsible for identifying and resolving various errors whether they come from hardware or software. The purpose of this research is to identify all the execution activities and solving techniques under the assumptions of the heterarchical control architecture. And we model the execution module in object-oriented modelling technique for generalization. The execution module modeled in object-oriented concept can be adopted to the other execution module easily. This paper also proposes a classification scheme for execution activities of the heterarchical control architecture. Petri-nets are used as a unified framework for modeling and controlling execution activities. For solving the nonexistence of a supervisor, a negotiation-based solution technique is utilized.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.3
• /
• pp.448-459
• /
• 2012

It is important to understand how we can deal with elements for the modeling of neural networks when we are investigating the dynamical performance and the information processing capabilities. The information processing capabilities of model neural networks will change for different response, synaptic weights or learning rules. Using the statistical neurodynamics method, we evaluate the capabilities of neural networks in order to understand the basic concept of parallel distributed processing. In this paper, we explain the results of theoretical analysis of the effects of the hysteretic property on the performance of sequential associative neural networks.