• The KIPS Transactions:PartD
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• v.9D no.1
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• pp.111-126
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• 2002

As the technical aspect of the web system development is, unlike the existing main frame or client/server environment, greatly influenced by the dynamic and variable factors and carried out in a comparatively short period, practical and efficient process to which the developer may adapt with ease is very much required for the web system development. However, while the technological substitute, language and architecture composition have been much discussed, in connection with web system development growing rapidly, standardized development process and its deliverables have been rarely discussed. This thesis analyzes problems of the existing web system development processes and as the substitutes for them, proposes web system development process based on the domain features derived from the concepts of iteration and increment. For the classification of domains, five domains in total are set by interlocking web system factors and web site types and the workflows for two domains applied to projects are incorporated focused on work content and deliverables. The proposed process applies to the development of intranet system and is compared with the existing web development processes by the measure classified into components and elements.

• The KIPS Transactions:PartA
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• v.13A no.6 s.103
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• pp.481-488
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• 2006

FRP(Functional Reactive Programming) is a kind of embedded language in Haskell, it declaratively program reactive system based on two essential high-order types named behavior and events. This Paper design and implementation RT-FRP(Real-time Functional Reactive Programming) translator for using FRP in embedded systems with many constraints. The RT-FRP translator generates a C Program from an RT-FRP program according to the operational semantics of the RT-FRP language. To show the effectiveness of the RT-FRP translator, we loaded and executed the test program generated by the translator onto a real embedded system, LEGO Mindstorm. According to the experimental result, the reactive system software can be programmed more concisely using RT-FRP than using an imperative counter part although the size of the binary code is rather increased.

• Journal of Communications and Networks
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• v.16 no.4
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• pp.407-414
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• 2014

The Internet is a highly distributed and complex system consisting of billion devices and has become the field of various kinds of conflicts during the last two decades. As a matter of fact, various actors utilise the Internet for illicit purposes, such as for performing distributed denial of service attacks (DDoS) and for spreading various types of aggressive malware. Despite the fact that numerous services provide information regarding the threat level of the Internet, they are mostly based on information acquired by their sensors or on offline statistical sampling of various security applications (antivirus software, intrusion detection systems, etc.). This paper introduces proactive threat observatory system (PROTOS), an open-source early warning system that does not require a commercial license and is capable of estimating the threat level across the Internet. The proposed system utilises both a global and a local approach, and is thus able to determine whether a specific host is under an imminent threat, as well as to provide an estimation of the malicious activity across the Internet. Apart from these obvious advantages, PROTOS supports a large-scale installation and can be extended even further to improve the effectiveness by incorporating prediction and forecasting techniques.

• The KIPS Transactions:PartD
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• v.19D no.1
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• pp.39-48
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• 2012

In order to quickly understand which changes of source codes have been made and to perform effective maintenance of a system, it is important to visualize the changed parts. Although there are many works for analyzing software changes, there are few works for visualizing both of the change types and change quantifications for Java based systems. In this paper, we propose a change analysis technique based on class diagram and provide a change visualization technique by using change quantification information. In order to check the structural changes in source codes, source codes are transformed to class diagrams by reverse engineering methods. On the class diagrams, the changes are analyzed and quantified by numbers. Based on the change quantification, the changes are visualized on the class diagram by color spectrum. By using visualization techniques, maintainers can easily recognize the code changes to reduce the cost and time of maintenance.

• Journal of Information Processing Systems
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• v.8 no.2
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• pp.213-240
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• 2012

Safety critical systems, real time systems, and event-based systems have a complex set of events and their own interdependency, which makes them difficult to test ma Safety critic Safety critical systems, real time systems, and event-based systems have a complex set of events and their own interdependency, which makes them difficult to test manually. In order to cut down on costs, save time, and increase reliability, the model based testing approach is the best solution. Such an approach does not require applications or codes prior to generating test cases, so it leads to the early detection of faults, which helps in reducing the development time. Several model-based testing approaches have used different UML models but very few works have been reported to show the generation of test cases that use events. Test cases that use events are an apt choice for these types of systems. However, these works have considered events that happen at a user interface level in a system while other events that happen in a system are not considered. Such works have limited applications in testing the GUI of a system. In this paper, a novel model-based testing approach is presented using business events, state events, and control events that have been captured directly from requirement specifications. The proposed approach documents events in event templates and then builds an event-flow model and a fault model for a system. Test coverage criterion and an algorithm are designed using these models to generate event sequence based test scenarios and test cases. Unlike other event based approaches, our approach is able to detect the proposed faults in a system. A prototype tool is developed to automate and evaluate the applicability of the entire process. Results have shown that the proposed approach and supportive tool is able to successfully derive test scenarios and test cases from the requirement specifications of safety critical systems, real time systems, and event based systems.

• Journal of Digital Contents Society
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• v.18 no.8
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• pp.1585-1591
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• 2017

In this study, we propose the application of exhibition contents using virtual environment technology in exhibition space. Research on the virtual environment is continuing. Particularly, research on virtual reality technology is one of the most active research fields. As researches and developments of augmented reality technologies have been carried out with the spread of smart phones, researches on virtual reality technologies have also made a lot of progress with emphasis on games and interactivity. Especially, development of hardware, software, and content is accelerating this year, including the development of various types of physical reality devices, especially HMD (Head Mounted Device) equipment and new product announcements. We want to study and apply the environment in which the system based on this virtual reality technology can approach and experience more user friendly in the exhibition space.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.6
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• pp.152-158
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• 2013

The purpose of this study is to investigate cooling performance of high power LEDs from 100 to 200 W class by using a jet impingement cooling module. The numerical analysis of forced convection cooling inside cooling module is carried out using a multi-purpose CFD software, FLUENT 6.3. In the experiments, the LED cooling system consists of jet impingement module, heat exchanger, water reservoir, and pump. In the present study, the cooling performance of jet impingement cooling module is investigated to determine the effect of the heat sink types on the impinging surface, the space and length of fins. Numerical and experimental studies show the reasonable agreement of LED metal PCB temperature between those results and give the optimized design parameters such as the space of fin and the length of fin. Also, the pin fin type of heat sink is found to be more efficient than the plate type heat sink in jet impingement cooling.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.1
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• pp.14-25
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• 2003

The purpose of this study was to analyze the stress pattern in different bone densities surrounding fin-type implant fixtures under the vertical and inclined loads ($30^{\circ}) of 200N. Von-Mises stress, the pricipal stress, and the displacement on the implant fixtures under the loads were calculated by using the finite element method. Four different types of bicon implant fixture were used for this study. The geometries of implant fixtures to develop the model were used by a sales brochure and profile project. Three-dimensional finite element model of the mandible was developed with 6.0 mm implant in diameter wurrounded by approximately 2.5 mm of bone. Bone densities were classified according to the elastic modulus of the tree. The finite element program MSC PATRAN (MSC, Software Corp., USA) were used for analysis of stress distribution. The value of the Von-Mises stress, the pricipal stress, and the displacement on the implant fixtures under the vertical and inclined loads were decreased when the diameter of implant fixture was increased, and increased when the elastic modulus was decreased. The stress on implant fixture under the vertical and inclined loads was distributed through the length of implant fixtures in D3 and D4. The distribution of stress was influenced by the direction of loads. In the wide diameter of implants, the stress was developed at outer surface of bone. In conclusion, this study suggest that stress developing on the peri-implant tissues might be influenced by the dimension of implant, elastic modulus of bone, and direction of loads.

• The Journal of Korean Association of Computer Education
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• v.5 no.1
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• pp.85-98
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• 2002

In this study, We are developed learner traits analysis and profile management software modules to develop learnable courseware fits to learner's individual traits in cyber learning system. We specified learner's personal information, performance information, preference information and portfolio information as learner's traits variables in this study, these four types of information are managed in learner profile management DB based on elaborate analysis to learner's traits. And we consists of curriculum sequencing module using high and low level sequencing technology, these are used in organizing learning contents sequencing with learning topic and specific learning task. The advice algorithm module developed based on adaptive navigational support and rule based technology. This Result of Research are able to be used for develop learnable courseware fits to learner's individual traits in cyber learning systems.

• Publications of The Korean Astronomical Society
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• v.11 no.1
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• pp.1-26
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• 1996

We have built a near-infrared imaging camera with a PtSi array detector manufactured by the Mitsubishi Company. The PtSi detector is sensitive in the wavelength range 1 to $5{\mu}m$. Quantum efficiency of PtSi is much lower than that of InSb and HgCdTe types. However, the PtSi array has advantages over the latter ones: (i)The read-out noise is very low; (ii)the characteristics of the array elements arc uniform and stable; (iii)it is not difficult to make a large PtSi array; and (iv) consequently the price is affordably low. The array used consists of $512{\times}512$ pixels and its size is $10.2\;mm{\times}13.3\;mm$. The filter wheel of the camera is equipped with J, H, K filters, and an aluminum plate for measuring the dark noise. The dewar is cooled with liquid nitrogen. We have adopted a method of installing the clock pattern and the observing softwares in the RAM, which Gill he easily used for other systems. We have developed a software with a pull-down menu for operating the camera and data acquisition. The camera has been tested by observing $\delta$ Orionis.