• The KIPS Transactions:PartC
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• v.12C no.5 s.101
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• pp.709-716
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• 2005

QoS is an important requirement of the FTTH (Fiber To The Home) subscriber in access network using E-PON (Ethernet Passive Optical Network). In this research, we describe the structure of the access network and propose a bandwidth guarantee scheme for subscriber and service according to the requirements of the subscriber, service and system. This scheme uses two kinds of the classification table, which are called 'service classification table' and 'subscriber classification table.' Using the classification table, we can identify the flow of the subscriber and service. Also, we compute the number of hash table entry to minimize the loss ratio of flows using the M/G/k/k queueing model. Finally, we apply the DRR scheduling through virtual queueing per subscriber instead of the aggregated class.

• The KIPS Transactions:PartC
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• v.17C no.3
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• pp.299-306
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• 2010

IPTV and VoIP services are considered as killer applications over Mobile WiMAX network, which provideshigh mobility and data rate. Among those which affect the quality of voice in those services, the jitter buffer or playout buffer can compensate the poor voice quality caused by the packet drop due to frequent route change or differences among routes between service endpoints. In this paper, we analyze the correlation between the sleep interval length and jitter buffer size in order to guarantee a predefined level of voice quality. For this purpose, we present an end-to-end delay model considering additional delay incurred by the WiMAX PSC-II sleep mode and a VoIP service quality requirement based on the delay constraints. Through extensive simulation experiments, we also show that the increase of jitter buffer size may degrade the voice quality since it can introduce additional packet drop in the jitter buffer under WiMAX power saving mode.

• The KIPS Transactions:PartC
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• v.16C no.4
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• pp.487-494
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• 2009

VOD(Video On Demand) that provides streaming service according to the user's requirement in real time, consists of the video streaming server and the client system. Since it is very hard to apply the traditional server-client model that a server communicates with many clients through 1:1 connection to VOD system because it requires very high network bandwidth, many researches have been done to address this problem. Batching technique is one of VOD system based on Multicast that requires very small network bandwidth. However, the batching based VOD system has a limitation that it is very hard to provide VCR(Video Cassette Recorder) ability. In this paper, we propose a technique that reduces the required network bandwidth to provide VCR function by using the characteristic of MPEG, one of international video compression standard. In the proposed technique, a new video stream for VCR function is constructed with I pictures that is able to be decoded independently. The new video stream for VCR function is transmitted with the video stream for normal play together in Batching manner. The performance evaluation result shows that the proposed technique not only reduces the required network bandwidth and memory usage but also decreases the CPU usages.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.5
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• pp.203-208
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• 2013

As smartphones are rapidly and widely spread, their applications request gradually larger computation power. Recently, in the personal computer, computing power of hardware has exceeded performance requirement of software sometimes. Computing power of smartphone, however, will not grow at the same pace as demand of applications because of form factor to seek thinner devices and power limitation by relatively slow technical progress of battery. Computation offloading is getting huge attention as one of solution for the problem. It has not commonly used technology in spite of advantages for performance and power consumption since the existing offloading frameworks are difficult for application developer to utilize. This paper presents an application developer-friendly offloading framework, named SorMob. Based on Aspect Oriented Programming model, SorMob provides a convenient environment for application development, and its performance was verified by comparing with the existing offloading framework.

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.3
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• pp.288-298
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• 2000

Digital assets denote multimedia information that exists in the form of digitized materials such as images, audio, and video. The management of digital assets demands much effort because of a huge amount of storage space requirement and multidimensional characteristics of the information needed to describe their contents. In this paper, we design and implement a Digital Asset Manager that stores and manages digital assets efficiently. Among the various types of digital assets, we focus on the video asset which has the highest complexity. Our Digital Asset Manager provides various facilities for digital contents authoring applications. In the Digital Asset Manager, video assets are managed by using a hierarchical model in order to ensure efficient accesses to any part of a video asset. Our system also guarantees the independence from the storage platform, and provides a fast content-based similarity search method on the digital assets.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.55
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• pp.33-62
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• 2012

Arbitration is an essential methods of settlement for disputes in international commercial transaction. UNCITRAL Arbitration Rules have been in force after adoption in 1976. Over the 30 years, UNCITRAL Arbitration rules have been modeled for domestic and international arbitration institutes for setting and revision on their arbitration rules. UNCITRAL Committee has published the revised Arbitration Rules which entered into force after 15 August 2010. Therefore new version of arbitration rules are substituted for the previous version of UNCITRAL Arbitration Rules 1976 since its enforcement. The revised arbitration rules of UNCITRAL have been changed in various items for convergence with new trends and modern practices on arbitration including information communication and technology. The revision of arbitration rules focused on resolving problems in practice and codifying best practice to enhance the efficiency of arbitration conducted under the rules. There are considerable in a number of important respects on the removing the restricted in writing requirement for information technology, adapting the multiparties arbitration, joinder arbitration, truncated arbitral tribunal and adjustment in terms and condition and construction simply. Also a number of provisions have been refined, varied and clarified with new articles included. Conclusively the new revised arbitration rules fill a number of gaps which became apparent in the UNCITRAL Arbitration Rules 1976 to bring into line with new modern practices of international arbitration rules in international commercial disputes. This paper focus on the study the problems and inspired points on significant revised provisions and its considerable points in arbitration environment. This paper is approaching to the comparisons of UNCITRAL revised Arbitration Rules 2010 with previous Arbitration Rules 1976 of UNCITRAL and International Arbitration Rules 2011 of KCAB.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.1
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• pp.71-79
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• 2014

A parallelization of the bi-conjugate gradient solver for the pressure equation of the CUPID (component unstructured program for interfacial dynamics) code, which was developed for analyzing the components of a pressurized water-cooled reactor, was studied in a symmetric multi-processing system. The parallel performance was investigated for three typical parallel programming models (MPI, OpenMP, Hybrid) by solving incompressible backward-facing step flow at various grid resolutions. It was confirmed that parallel performance was low when problem size was small or the memory requirement for each thread was considerably higher than the cache memory. Furthermore, it was shown that MPI was better than OpenMP regardless of the problem size, and Hybrid was the best when the number of threads was relatively small.

• Journal of Biomedical Engineering Research
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• v.28 no.1
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• pp.17-23
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• 2007

Long-term potentiation (LTP) of synaptic transmission is the most widely studied model for learning and memory. However its mechanisms are not clearly elucidated and are a subject for intense investigation. Previous attempts to decipher cellular mechanisms and network properties involved a current-source density analysis (CSDA) of the LTP from small animal hippocampus measured with a limited number of microelectrodes (typically <3), only revealing limited nature of spatiotemporal dynamics. Recent advancement in multi-electrode array (MEA) technology allows continuous and simultaneous recordings of LTP with more than 60 electrodes. However CSDA via the standard Laplacian transform is still limited due to its relatively high sensitivity toward noise, inability of resolving overlapped current sources and sinks, and its requirement for tissue conductivity values. In this study, we propose a new methodology for improved CSDA. Independent component analysis and its joint use (i.e., Joint-ICA) are applied to extract spatiotemporal components of LTP. The results show that ICA and Joint-ICA are capable of extracting independent spatiotemporal components of LTP generators. The ICs of LTP indicate the reversing roles of current sources and sinks which are associated with LTP.

• Korean Institute of Interior Design Journal
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• v.14 no.1
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• pp.168-176
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• 2005

As the pluralistic value in which various cultures and trends exist develops the world at large, development of interior design is required to examine consumers by group. This requirement purports to set up a strategic model of operating interior design organizations under cross-cultural (past and present) enviroment, not to express new researches of interior design following the direction of the developed media service. Based on the educational and complex cultural approach to design matters - the key issue in solving the cross-cultural design matters, this paper has suggested the structure of semi-centralized design process and the system for finding out consumers' trends under the new media-based cultural design environment. This study presents some expected effects. First, it will be able to enhance the consumer-oriented design mind by providing the information on the interior design system and design trend. Through analyzing the lifestyle in the 21st century and providing the relevant information, it will lead irrlprovement in living environment. And further, by using the program of searching consumers' new preference, the system of grasping consumers' propensity and making decisions will be materialized. Secondly, based on the background database of forecasted consumers' trends, marketing strategies can be established. Thirdly, through the better technology of designing living environment, efficiency will be increased and the economic foundations through use of new database will be constructed. Fourth, systematic interior design can be developed. Strategic correspondence to consumers' desires and reinforcement of competitiveness will become possible with development of database. By encouraging consumers' participation under digital environment, their trends can be forecasted, and by efficiently using information and new technology, resources can be saved and further, additional costs for promotion and sales will be reduced.

• Wind and Structures
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• v.26 no.6
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• pp.397-413
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• 2018

Excitation mechanism of interference effect between two tall buildings is investigated with wind tunnel experiments. Synchronized building surface pressure and flow field measurements by particle image velocimetry (PIV) are conducted to explore the relationship between the disturbed wind flow field and the consequent wind load modification for twin buildings in tandem. This reveals evident excitation mechanisms for the fluctuating across-wind loads on the buildings. For small distance (X/D < 3) between two buildings, the disturbed flow pattern of impaired vortex shedding is observed and the fluctuating across-wind load on the downstream building decreases. For larger distance ($X/D{\geq}3$), strong correlation between the across-wind load of the downstream building and the oscillation of the wake of the upstream building is found. By further analysis with conditional sampling and phase-averaged techniques, the coherent flow structures in the building gap are clearly observed and the wake oscillation of the upstream building is confirmed to be the reason of the magnified across-wind force on the downstream building. For efficient PIV measurement, the experiments use a square-section high-rise building model with geometry scale smaller than the usual value. Interference factors for all three components of wind loads on the building models being surrounded by another identical building with various configurations are measured and compared with those from previous studies made at large geometry scale. The results support that for interference effect between buildings with sharp corners, the length scale effect plays a minor role provided that the minimum Reynolds number requirement is met.