• Journal of applied mathematics & informatics
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• v.9 no.2
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• pp.879-890
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• 2002

In this paper we consider open queueing system with a Poisson arrival process which have a finite upper bound on the arrival rate for which the system is stable. Interpolation approximations for quantities of interest, such as moments of the sojourn time distribution, have previously been developed for such systems, utilizing exact light and heavy traffic limits. These limits cannot always be easily computed for complex systems. Thus we consider an interpolation approximation where all of the relevant information is estimated via simulation. We show that all the relevant information can in fact be simultaneously estimated in a single regenerative simulation at any arrival rate. In addition to light and heavy traffic limits, both the quantity of interest and its derivative (with respect to the arrival rate) are estimated at the arrival rate of the simulation. All of the estimates are then combined, using a least squares procedure, to provide an interpolation approximation.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2499-2502
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• 2005

Universal Serial Bus (USB) is one of the most popular communication interfaces. When USB is used in more extended range, especially configuring home network by connecting multiple digital devices each other, USB interface uses the bandwidth in the way of Time Division Multiplexing (TDM) so that the bottleneck of bus bandwidth can be brought under the heavy traffic. In this paper, the more effective usage of bus bandwidth to overcome this situation is introduced. Basically, in order to realize the system for transferring real-time moving picture data among digital information devices, we analyze USB transfer types and descriptors and introduce the method to enhance the detailed performance of isochronous transfer that is one of USB transfer types.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.5
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• pp.107-113
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• 2000

The purpose of this study is to investigate the effects of soil amendments for reducing soil compaction at heavy traffic area in golf course. Major results of this research are summarized at follows: 1. In the Lab. experiment, the porosity was improved significantly when the materials, such as peatmoss, charcoal, and tire chip mixtures were used respectively. Especially mixture of sand and 20% peatmoss showed higher effectiveness (10%) in porosity, comparing with ordinary sand. This soil mixture(sand 80%+peatmoss 20%) was observed the best in water retention, soil hardness and hydrauric conductivity. 2. In the greenhouse experiment, traffic pressure was given 7 times a day on several combination of mixture treatments to see the top dry weight. The soil mixture of 20% peatmoss showed the highest in the top dry weight. When the more traffic pressure(15 time/day) were given on the different treatment, the top dry weight was significantly reduced. However, the mixture of 20% peatmoss also had the least influence on this type of heavy traffic. 3. In the field experiment, the soil amendments were treated in traffic area f golf course, and observed at 30days, 60days, 90days, 120days after treatment. Visual turf quality(color), root length and soil compaction were compared to those of control. As a result, overall treatments with soil amendments were effective, which showed better turf quality and less soil compaction. 4. In the field test, physical characters of soil (such as soil hardness and hydrauric conductivity) in sand+tire chip+peatmoss(60:20:20, %, v/v) treatment was significantly improved. Also in the slow increasing of traffic, the soil compaction was the most effective in reducing soil hardness.

• Journal of Environmental Science International
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• v.14 no.6
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• pp.605-611
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• 2005

The aim of this study was to analyze the local distribution of the heavy metal concentration in Daegu and Ulsan which were divided into the residual areas, the traffic dense areas and the industrial areas. The Inductively Coupled Plasma(ICP) was used to analyze heavy metals, such as As, Cr, Hg, Zn, Cd, Pb, Cu and minor metals, such as Fe, Si, Mg, Ca, AI, Na, K. The results of this analysis showed that the content of heavy metals which was classified by districts in Daegu and Ulsan was the highest in the industrial areas followed by the traffic dense areas and the residual areas. Compared to the level of heavy metals of national and local soil survey network in 2003, contamination of heavy metals in Daegu was lower than national average. However, the content of Cd, As, Zn in Ulsan was respectively 13.38 times, 472 times and 2.65 times higher than national average contamination. In addition, compared to the soil pollution level of the environmental protection law, contamination of all areas in Daegu was lower. But the content of As at the industrial areas in Ulsan was 10.71 times higher than standard of soil pollution and 4.28 times higher than standard of measures against soil contamination.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.3 s.120
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• pp.274-281
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• 2007

Road traffic noise is not produced by any one factor rather it occurs as a composition of various factors. Its occurrence is made by running engine noise, tire frictional, and exhaust noise etc. The quality of the noise depends on the size of the vehicles, rotation and engine speed, vehicle load, package state of the road and incline etc. The occurrence of any noise level of heavy trucks appears louder than smaller vehicles and the noise levels produced differs according to speed and load etc between similar size vehicles. Other factors such as traffic density, average speed, mixing rate of heavy vehicles, and the distance between vehicles also generate road traffic noise. In this paper we examine 2, 4, and 6-lane roads in Jeonju. Consequently, this study examines the means used to measure road traffic noise. It was found that when there is a large traffic density and the average velocity is below 70 km/h, the noise level could receive a relative proper value by the current measuring means. But in the case of night-time, it was found that the current measuring method is inapposite.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.3
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• pp.10-18
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• 2007

According to the recent growth of the internet commercialization and differentiated QoS(quality of service), statistical traffic modeling is necessary for forecasting and controlling future network capacity. This paper reviews tile essential components in web workloads. And I propose adjusted internet traffic modeling using heavy-tailed distributions and intervention techniques.

• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.105-105
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• 2018

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.277-282
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• 2006

Road traffic noise is not produced by any one factor rather occurs as a composition of various factors. Its occurrence is made by running engine noise, tire frictional, and exhaust noise etc. The quality of the noise depends on the size of the vehicles, rotation and engine speed, vehicle load, package state of the road and incline etc. The occurrence of noise level of heavy trucks appears louder than smaller vehicles and the noise levels produced differs according to speed and load etc between similar size vehicles. Other factors such as traffic density, average speed, mixing rate of heavy vehicles, and the distance between vehicles also generate road traffic noise. In this paper we examine 2, 4, and 6-lane roads in Jeonju. Consequently, this study examined the means used to measure road traffic noise. It was found that when there is a large traffic density and the average velocity is below 70 km/hr, the noise level could receive a relative proper value by the current measuring means. But in the case of night-time, it was found that the current measuring method is inapposite.

• Economic and Environmental Geology
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• v.38 no.3 s.172
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• pp.221-236
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• 2005

In order to investigate the contamination levels and dispersion patterns of heavy metals such as Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn by urbanization, soils beneath roadside-trees and leaves of Ginkgo biloba were collected from Seoul area during October to November in 2001. All tree leaves were grouped into washed and unwashed ones. The pH of most soil ranges from 6 to 9 indicating a weak acidic and alkaline. The element couples of Cd-Co, Cr-Ni and Zn-Cu-Pb have good correlation in soils, and contamination sources of Cd-Co, Cr-Ni and Zn-Cu-Pb could be similar. High correlation coefficients among Pb, Cu and Zn in G. biloba indicates that these elements show the similar behavior during the metabolism processes. From the results of pollution index calculation for soils, industrialized and heavy traffic area were severly polluted by heavy metals such as Cd, Cu, Pb and Zn. By the discriminant analysis, industrialized and heavy traffic areas are enriched in the order of Ni> Cr> Pb. Cadmium is useful to discriminate between industrialized and heavy traffic areas, Co and Pb are highly enhanced in heavy traffic area.

• Journal of KIISE:Information Networking
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• v.37 no.5
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• pp.317-326
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• 2010

Nowadays, transmission bandwidth for network traffic is increasing and the type is varied such as peer-to-peer (PZP), real-time video, and so on, because distributed computing environment is spread and various network-based applications are developed. However, as PZP traffic occupies much volume among Internet backbone traffics, transmission bandwidth and quality of service(QoS) of other network applications such as web, ftp, and real-time video cannot be guaranteed. In previous research, the port-based technique which checks well-known port number and the Deep Packet Inspection(DPI) technique which checks the payload of packets were suggested for solving the problem of the P2P traffics, however there were difficulties to apply those methods to detection of P2P traffics because P2P applications are not used well-known port number and payload of packets may be encrypted. A proposed algorithm for identifying P2P heavy traffics based on flow transport parameters and behavioral characteristics can solve the problem of the port-based technique and the DPI technique. The focus of this paper is to identify P2P heavy traffic flows rather than all P2P traffics. P2P traffics are consist of two steps i)searching the opposite peer which have some contents ii) downloading the contents from one or more peers. We define P2P flow patterns on these P2P applications' features and then implement the system to classify P2P heavy traffics.