• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.959-962
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• 2003

At the processing capabilities and operating frequency of embedded system are growing, so is the needed data bandwidth to fully utilize the processing capability. The ability to transfer huge amount of data between the embedded core and external devices is required for efficient system operation. In this paper, the data communication architecture for the mixed-clock system is proposed. The dynamic priority adaptation algorithm for bus arbitration is proposed for bandwidth guarantee. The communication architecture that incorporates the proposed arbitration algorithm adapts the priority of communication components dynamically based on the information from FIFO. The experiments show that the measured bandwidth of each component traces the required bandwidth well compared to the other arbitration algorithms

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.1656-1660
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• 2006

Distributed coordination function(DCF) is the primary random access mechanism of IEEE 802.11, which is the basic protocol of wireless LAN based on the CSMA/CA protocol. It enables fast installation with minimal management and maintenance costs and is a very robust protocol for the best effort service in wireless medium. The current DCF, however, is known to be unsuitable for real-time applications such as voice message transmission. In this paper, we focus on the performance issues of IEEE 802.11 which accommodate the prioritized messages. Existing results use the initial window size and backoff window-increasing factor as tools to handle the priority of the messages. Instead, we introduce a novel scheme which chooses the backoff timer with arbitrary probabilities. By this, one can greatly reduce the backoff delay of the lower priority messages without degrading the performance of higher priority.

• IEMEK Journal of Embedded Systems and Applications
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• v.2 no.4
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• pp.260-273
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• 2007

The wireless sensor network (WSN) nodes are required to operate for several months with the limited system resource such as memory and power. The hardware platform of WSN has 128Kbyte program memory and 8Kbytes data memory. Also, WSN node is required to operate for several months with the two AA size batteries. The MAC, Network protocol, and small application must be operated in this WSN platform. We look around the problem of memory and power for WSN requirements. Then, we propose a new computing model of system software for WSN node. It is the Atomic Object Model (AOM) with Dual Priority Scheduling. For the verification of model, we design and implement IEEE 802.15.4 MAC protocol with the proposed model.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.8
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• pp.1475-1484
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• 1994

In this paper, a priority scheduling algorithm with double threshold and a traffic control mechanism with hysteresis effect are proposed. The double threshold priority scheduling is studied based on HOL and QLT. The hysteresis effect traffic control is specified by hysteresis effect QLT and traffic rate control. According to the simulation results, it can be shown that the proposed dynamic priority scheduling brings better processing performance than the existing QLT algorithm. And the results demonstrate that QLT and traffic rate control with hysteresis effect enhance the performance in comparison with those of single threshold.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.6
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• pp.1470-1479
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• 1996

It was already proved that ATM has stability and flexibility of service applications, but because of the various characteristics of traffic and the QoS on user demandcaused by them, there are so many researches for traffic control method. In this paper, in order to give the more similar properties of the real traffic to the existing input traffic source, dividing them into four classes with different characteristics, and We proposed the integrated dynamic priority method, IDP which has advantages of the DMLT and the DQLT for time dynamic priority. Thus, it makes input queues about each of traffic classes and thresholds, and then use modified DMLT and DQLT methods. It has goal that proposed method to get more reliability and stability with advantage low loss of the DMLT, low delay of DQLT.

• The Journal of Information Technology and Database
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• v.4 no.2
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• pp.21-32
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• 1998

A primary concern of physical database design has been efficient retrieval and update of a record because predictable performance of a DBMS is indispensable to time-critical missions. To maintain such phenomenal performance, database manages often spends more than or as much as the goal of an organization can warrant. The motivation of this research stems from the fact that even predictable performance of a physical database can be hampered by stochastic query processing time, physical configurations of a database, and random arrival processes of queries. They all together affect the overall performance of a DBMS. In particular, if there are queuing delays due to limited capacity or during on-peak congestion, this paper suggest to prioritize database services. A surprising finding of this paper is that such a transition from a non-priority system to a corresponding priority-based system can be Pareto-improving in the sense that no users in the system will be worse off after the transition. Thus prioritizing database services can be a viable option for efficient database management.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.1
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• pp.41-48
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• 2006

In the evaluation of rural amenities, its properties are related with social, cultural, and environmental elements. In this study, Information Measure Model (IMM) and Cultural Property Priority Assessment Model (CPPAM) were developed adapting information measure model with text based surveying data. To apply developed model not only general properties but also specific surveyed data, Specific Information Gathering and Utilizing System (SIGUS) was constructed using the data in Dusan World encyclopedia. IMM shows priorities of cultural property by information in national-designated cultural properties. And CPPAM applied in surveying data in 2004 by Rural Resources Development Institute.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.137-159
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• 1998

For the construction of railroads in Metropolytan area based upon the outcome of the future demand forecast, a total of 21 lines including electrified double track segment of Ui-Jung-Bu↔Dong-Du-Chun(18.9km) in Kyung-Won Line is expected. Considering the financial difficulties and investment effect of the lines, this in the sequel brings about an important matter of deforming priority Investment plan to build electrified lines among the candidates. In the case of Japan, Tokyo metropolytan area covered In total by 2,070.1km of various lines, i.e., subway lines(241km), private lines(952.7km), JR lines(876.4km), provides convenient means of transportation for the coummuters and makes a contribution to the development of its neighboring areas and to the expansion of settlement areas. Comparing the total length per 1,000$\textrm{km}^2$, Tokyo(105), Paris(117), and London(115) are at least 6 times as large as ours(15). The purpose of this study is two fold provide a basic scheme for building railroads in metropolytan area and determine priority order in accordance with some evaluation criteria.

• 전자공학회논문지 IE
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• v.48 no.3
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• pp.16-19
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• 2011

Differentiated Service is an IP QoS ensuring method based on packet marking that allows packets to be prioritized according to user requirements. During the time of congestion, more low priority packets are dropped than high priority packets. Different policy models are used to determine how to mark the packet. This paper investigated the performance of Differentiated Service using time sliding window with 3 color marking (TSW3CM). Simulation results using NS-2 showed that Differentiated Service can provide the quality of service requirements.

• Korea Journal of Hospital Management
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• v.14 no.2
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• pp.21-40
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• 2009

The importance-performance analysis (IPA) is a widely used analytical technique that produces a priority of managerial attention for the customer satisfaction. This study attempted to compare various different approaches of IPA such as direct and indirect measurement of importance, and traditional four quadrants grid model and diagonal grid model of IPA. Data on 17 inpatient service quality attributes were collected from 234 inpatients of a general hospital. Eight IPA grids were produced to compare the result of each model. Based on the study results the strength and weakness of each model were discussed, and a set of recommendations for practical application of the IPA in hospital settings was suggested.