• Journal of Korea Game Society
• /
• v.16 no.2
• /
• pp.111-118
• /
• 2016

Global illumination is key factor for realistic image but it is not common in realtime rendering due to its complexity. Visibility of $2^{nd}$ lights is hard to determine because we should process all object for each $2^{nd}$ light. In this paper, we reuse visibility of static objects. We present an indirect illumination algorithm which shows good performance and provides exact $2^{nd}$ light visibility when the scene has small number of moving objects. Our method renders correct image while showing good performance.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.58 no.3
• /
• pp.276-284
• /
• 2009

In this paper, we develop the image transfer remote maintenance monitoring system for hand held device which can compensate defects of human mistake. The human mistakes always happen when the worker communicate information each other to check and maintenance the equipment of the power plant under bad circumstance such as small place and long distance in power plant. A worker couldn't converse with other when in noisy place like Power plant. So, we make some hand device for handy size and able to converse in noisy place. The developed system can have improvement of productivity through increasing plant operation time. And developed system is composed of advanced H/W(hard ware) system and S/W(soft ware)system. The H/W system consist of media server unit, communication equipment with hand held device, portable camera, mike and head set. The advanced s/w system consist of data base system, client pc(personal computer) real time monitoring system which has server GUI(graphic user interface) program, wireless monitoring program and wire ethernet communication program. The client GUI program is composed of total solution program as pc camera program, and phonetic conversation program etc.. We analyzed the required items and investigated applicable part in the image transfer remote maintenance monitoring system with hand held device. Also we investigated linkage of communication protocol for developed prototype, developed software tool of two-way communication and realtime recording skill of voice with image. We confirmed the efficiency by the field test in preventive maintenance of plant power.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2008.10a
• /
• pp.873-877
• /
• 2008

There were many exposed problems in previous authentication method on LAN. Especially Open System Authentication Method, Shared Key Method, Mac Based Authentication Method are very hard to use in wireless network that needs security. So now, many researches have been performed about $802.1{\times}$ and user authentication method applying PKI. But certificate verification protocol has been used abolished list called CRL since it's first usage of PKI, there were still has a problem about distribution point. In this paper, I applied CVS to use CA direct not to use CRL and OSCP server in order to improve this problems.

• Journal of Information Display
• /
• v.8 no.4
• /
• pp.27-31
• /
• 2007

In this paper, we present an efficient tiled stereo display system for tangible meeting. For tangible meeting, it is important to provide immersive display with high resolution image to cover up the field of view and provide to the local user the same environment as that of remote site. To achieve these, a high resolution image needs to be transmitted for reconstruction of remote world, and it should be displayed using a tiled display. However, it is hard to transmit high resolution image in real time due to the limit of network bandwidth, and so we receive multiple images and reconstruct a remote world with received images in advance. Then, we update only a specific area where remote user exists by receiving low resolution image in realtime. We synthesize the transmitted image to the existing environmental map of remote world and display it as a stereo image. For this, we developed a new system which supports GPU based real time warping and blending, automatic feature extraction using machine vision technique.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.8
• /
• pp.1463-1472
• /
• 2008

We propose Framework that (should) have data interoperability between Legacy DataBases using Proxy DataBases based on XMDR(eXtended Meta-Data Registry) Data Hub in this papers. It may occur some problems among data structure, semantics and other heterogeneous problems between interoperability of legacy DB on cooperation environment. Also, It is hard to keep consistency of Data that changes on realtime, regardless of data variety and type. In this paper, Using XMDR data hub, we solve the problem that was occurred by data integration and interoperability between legacy DB. We suggest the framework which are compatible with any class and type of interoperability-data and offer accurate information with consistency in real-time using proxy database.

• Journal of KIISE:Information Networking
• /
• v.34 no.5
• /
• pp.379-388
• /
• 2007

With proliferation of computer and wireless network technology, it is common to access Internet through wireless network using mobile device. Ratio of using streaming media out of many applications through Internet is increasing not only in wired network but also in wireless network. Streaming media is much bigger than other contents and requires more network bandwidth and more computing resources. However mobile devices hate relatively poor computing resource and low network bandwidth. If media streaming service is provided for mobile devices without any consideration about network bandwidth and computing power, it is hard for the client to get high qualify service. Since mobile device is supported with very limited energy from the battery, media streaming should be adjusted to varying energy state of mobile device in realtime to ensure complete playback of streaming media. In this paper, we propose DFRC to provide high qualify service to mobile client through wireless network by controlling the number of frames transmitted to client based on computing resource and energy state of mobile device.

• The Journal of the Korea Contents Association
• /
• v.9 no.8
• /
• pp.158-165
• /
• 2009

Counselling between a patient and a doctor is crucial in telemedicine. In order for the doctor to examine the patient accurately, it needs an auscultation, at least. Currently, some video conference systems are implemented but it is hard to use them in the case of an cardiac disorder, because the patients suffering from cardiac disorder cannot be examined by a stethoscope over Internet. To solve this problem, the remote counselling service has to support real time transmission of the heart sound of the patient. In this paper, we present a remote counselling system with stethoscope. We also design and implement the system in order for health monitor to connect the patient with his attending physician for the environment of u-healthcare service. The proposed system supports a mobility for doctor and patient by exchanging IP addresses at an user authentication protocol. The system implemented by this paper can be used for cardiac patients in remote clinical setting in the future.

• The KIPS Transactions:PartA
• /
• v.9A no.3
• /
• pp.301-310
• /
• 2002

Internet has been applied to the educational field such as data search, lecture by motion picture, realtime examination. Most questions made for these remote examinations use methods of making questions randomly using fixed questions or item pools. The designed system in this paper makes questions without knowing MARK-UP language and after undergoing examinations on Web. Also it readjusts degree of difficulty automatically on the basis of the rate of correct answers. In addition, this enables learners to perform feedback learning after examinations and subsequently learners themselves to adjust their degree of difficulty and undergo reexaminations. The automatic selection system makes it easy to select questions, possible to expect average marks and number of questions made, and to prevent that questions may be made too easy or too hard. For a remote examination, as there are much possibilities of dishonesty such as examination by proxy so different types of problems are made, and problems of the rationality caused from that can be avoided.

• Journal of the Korea Society of Computer and Information
• /
• v.16 no.12
• /
• pp.11-21
• /
• 2011

An embedded sensor is significantly influenced by its spatial environment, such as barriers or distance, through low power and signal strength. Due to these causes, noise data frequently occur in an embedded sensor. Because the information acquired from the embedded sensor exists in a time series, it is hard to detect an error which continuously takes place in the time series information on a realtime basis. In this paper, we proposes an error detection method based on time-series prediction that detects error signals of embedded sensors in real time in consideration of the physical characteristics of embedded devices. The error detection method based on time-series prediction proposed in this paper determines errors in generated embedded device signals using a stable distance function. When detecting errors by monitoring signals from an embedded device, the stable distance function can detect error signals effectively by applying error weight to the latest signals. When detecting errors by monitoring signals from an embedded device, the stable distance function can detect error signals effectively by applying error weight to the latest signals.

• Journal of Korea Game Society
• /
• v.14 no.6
• /
• pp.49-58
• /
• 2014

In particle-based fluid simulation, the yield stress is required for the deformation of the viscoelastic material like gel. von Mises's yield condition has been proposed to implement deformation of viscoelastic objects, but did not express the explosion. Furthermore, von Mises's yield condition is hard to approximate. We propose an ideal yield condition for viscoelastic object that reference from Tresca's yield condition. Unlike conventional particle-based simulation approximate the external power by the deformed length of the object, this paper is approximate the external power by area of the object. We check up that explosion was realistic when a viscoelastic object is compressed under the ideal yield condition.