• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.93-106
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• 2011

In this paper we describe an efficient and easy to use internet stopper, which is called AINS (Automatic Internet Stopper), which uses ARP spoofing scheme. Instead of forwarding packets to router for the case of hacking, in ARP spoofing, the AINS ignores all the packets so that internet stopping operates. The AINS program needs to be installed only in manager computer that does not require additional agent program. In addition to setting manually the stopping computer list, it is able to indentify network nodes automatically by analyzing broadcasting packets. The experimental results show that less than 4 secs for spoofing interval is enough for blocking internet usage regardless the number of computers and therefore network overhead is negligible. The AINS can indentify and control network nodes not only on same subnet but also on different subnet only if they are connected onto same ethernet switch physically. It is being used for an efficient tool for controling internet usage of university computer laboratory and also for an efficient network management.

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.2
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• pp.244-253
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• 2000

Since no single routing-switching combination performs the best under various different types of applications, a flexible network is required to support a range of polices. This paper introduces an implementation of a look-up table routing engine offering flexible routing and switching polices without performance degradation unlike those based on microprocessors. By deciding contents of look-up tables, the engine can implement wormhole routing, virtual cut-through routing, and packet switching, as well as hybrid switching, under a variety of routing algorithms. Since the routing engine has a piplelined look-up table architecture, the routing delay is as small as one flit, and thus it can overlap multiple routing actions without performance degradation in comparison with hardwired routers dedicated to a specific policy. Because four pipeline stages do not induce a hazard, expensive forwarding logic is not required. The routing engine can accommodate four physical links with a time shared cut-through bus or single link with a cross-bar switch. It is implemented using Xilinx 4000 series FPGA.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.1B
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• pp.59-66
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• 2012

The use of MPSoC has been increasing because of a rise of use of mobile devices and complex applications. For improving the performance of MPSoC, number of processor has been increasing. Standard MPI is used for efficiently sending data in distributed memory architecture that has advantage in multi processor. Standard In this paper, we propose a scalable distributed memory system with a low cost hardware message passing interface(MPI). The proposed architecture improves transfer rate with buffered send for small size packet. Three queues, Ready Queue, Request Queue, and Reservation Queue, work as previous architecture, and two queues, Small Ready Queue and Small Request Queue, are added to send small size packet. When the critical point is set 8 bytes, the proposed architecture takes more than 2 times the performance improvement in the data that below the critical point.

• The KIPS Transactions:PartA
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• v.10A no.3
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• pp.215-224
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• 2003

Since there are various networks and heterogeneity of nodes in Internet, the existing load-sharing algorithms are hardly adapted for use in Internet-based clustering systems. Therefore, in Internet-based clustering systems, a load-sharing algorithm must consider various conditions such as heterogeneity of nodes, characteristics of a network and imbalance of load, and so on. This paper has proposed an expanded-WF algorithm which is based on a WF (Weighted Factoring) algorithm for load-sharing in Internet-based clustering systems. The proposed algorithm uses an adaptive granularity strategy for load-sharing and duplicate execution of partial job for fault-tolerance. For the simulation, the to matrix multiplication using PVM is performed on the heterogeneous clustering environment which consists of two different networks. Compared to other algorithms such as Send, GSS and Weighted Factoring, the proposed algorithm results in an improvement of performance by 55%, 63% and 20%, respectively. Also, this paper shows that It can process the fault-tolerance.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.1
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• pp.63-76
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• 2001

As reusability becomes recognized more importantly, with the introduction of ObjectOriented Programming Languages, developers not only want to reduce development duration, but also to develop a proper system robustly and safely by renovating the Hot Spot in order to reuse the existing framework. When we perform these works, we need the development environment which is the Rapid Application Development tool, and the RAD tools provide us with the convenient development environment. The need of RAD tools is recognized by every Object-Oriented programmer, and many business enterprises are developing them. In this paper, we will present a design and implementation of module-based modeler as a method for developing technique to constmct user-driven Intranet environment for the generation of the program based on the framework. The framework modeler used Java language that is independent on platform, and applied the technique of OMT editor that provides the UML notation partially. Additionally, The modeler also includes the notations that are not supported in OMT editor. In addition to this characteristic, it is structured to develop system consistently with applying the Agent pattern, which is a design pattern suggested by ourselves, to send messages occurred between various Views. The existing MVC(Model-View-Controller) architecture does not have this function. Thus, this tool has a flexibility when user's requirements are changed, or functions are extended.

• The Journal of Korean Association of Computer Education
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• v.11 no.1
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• pp.57-64
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• 2008

This paper presents a web-based virtual educational system for Java language, which consists of a management system named Java Web Player (JWP) and creative multimedia contents for the lectures of Java language. The JWP is a Java application program free from security problems by the Java Web Start technologies that supports an integrated learning environment including three important learning procedures: Java concept learning process, programming practice process and assessment process. On-line voice presentation and its related texts together with moving images are synchronized for efficiently conveying creative contents to learners. Furthermore, a simple and useful compiler is included in the JWP for providing user-friendly language practice environment enabling such as coding, editing, executing, and debugging Java source files on the Web. Finally, simple multiple choices are given suddenly to the learners while they are studying through the JWP and the test results are displayed on the message box. In order to show the validity of the proposed virtual educational system we analysed and assessed the learners' academic performance on the five quizzes for one semester.

• Journal of Navigation and Port Research
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• v.31 no.8
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• pp.629-635
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• 2007

Reduced crew performance is frequently cited as a major causal factor in maritime accident causation. Although considerable research has been conducted on the hours of work undertaken by seafarers through interviews and the analysis of records, experimental studies to observe the effects of factors such as high workload, shift patterns, stress, sleep deprivation and disturbance on the cognitive performance of mariners have been limited. Other safety-critical transport industries, such as aviation and rail, have developed fatigue management tools to help manage the work patterns of their operators. Such a tool for mariners would assist shipboard crew, marine pilots and shore management in planning and improving work schedules. The overall aim of this paper is to determine a fatigue factor, which can be applied to human performance data, as part of a software program that calculates total cognitive performance. This program enables us to establish the levels of cognitive performance of a group of marine pilots to test a decision-making task based on radar information. This paper addresses one of the factors that may contribute to the determination of various fatigue factors: the effect of different work patterns on the cognitive performance of a marine pilot.

• Journal of KIISE:Information Networking
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• v.31 no.1
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• pp.11-19
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• 2004

P2P network environments provide users with direct data transmission and sharing facilities and those environments can be classified into hybrid P2P network environments and pure P2P network environments according to the arbitration mechanism among the peers in the network. In hybrid P2P network environments, there exists a server that maintains index information for the data to be shared and network isolation does not occur because every peer always keeps connection to the server. In pure P2P network environments, however, each peer directly connects to another peer and gets services without server intervention, and so, network isolation can occur when the mediating peer fails to work. In this paper. we propose a scheme for each peer to keep connection to other peers continuously by maintaining IP addresses of its neighbor peers and connecting to the peers when the mediating peer fails to work. Although the P2P application that uses our proposed framework should obtain one or more IP addresses of the neighbor peers manually, after instantiation, the application can do its job while maintaining connection to the network continuously and automatically. To evaluate our proposed scheme, we measured and analyzed the time for a peer to reconnect to the network when the mediating peer fails and the network isolation occurs.

• Journal of Advanced Navigation Technology
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• v.19 no.5
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• pp.423-432
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• 2015

This paper shows that design, manufacture and the performance of FC-NIC (fibre channel network interface card) for network unit configuration which is based on one of the 5 main configuration items of the common functional module for IMA (integrated modular Avionics) architecture. Especially, FC-NIC uses zynq SoC (system on chip) for host load reductions. The host merely transmit FC destination address, source memory location and size information to the FC-NIC. After then the FC-NIC read the host memory via DMA (direct memory access). FC upper layer protocol and sequence process at local processor and programmable logic of FC-NIC zynq SoC. It enables to free from host load for external communication. The performance of FC-NIC shows average 5.47 us low end-to-end latency at 2.125 Gbps line speed. It represent that FC-NIC is one of good candidate network for IMA.

• The KIPS Transactions:PartD
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• v.8D no.1
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• pp.71-80
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• 2001

Object-Oriented (OO) methodology to use the concept like encapsulation, inheritance, polymorphism, and message passing demands metrics that are different from structured methodology. There are many studies for OO software metrics such as program complexity or design metrics. But the metrics for the analysis class need to decrease the complexity in the analysis phase so that greatly reduce the effort and the cost of system development. In this paper, we propose new metrics to measure the complexity of analysis classes which draw out in the analysis phase based on Unified Process. By the collaboration complexity, is denoted by CC, we mean the maximum number of the collaborations can be achieved with each of the collaborator and detennine the potential complexity. And the interface complexity, is denoted by IC, shows the difficulty related to understand the interface of collaborators each other. We prove mathematically that the suggested metrics satisfy OO characteristics such as class size and inheritance. And we verify it theoretically for Weyuker' s nine properties. Moreover, we show the computation results for analysis classes of the system which automatically respond to questions of the it's user using the text mining technique. As we compared CC and IC to CBO and WMC, the complexity can be represented by CC and IC more than CBO and WMC. We expect to develop the cost-effective OO software by reviewing the complexity of analysis classes in the first stage of SDLC (Software Development Life Cycle).