• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권12호
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• pp.5948-5971
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• 2019

Estimating loss rates with the packet traces captured from some point in the middle of the network has received much attention within the research community. Meanwhile, existing intermediate-point methods like [1] require the capturing system to capture all the TCP traffic that crosses the border of an access network (typically Gigabit network) destined to or coming from the Internet. However, limited to the performance of current hardware and software, capturing network traffic in a Gigabit environment is still a challenging task. The uncaptured packets will affect the total number of captured packets and the estimated number of packet losses, which eventually affects the accuracy of the estimated loss rate. Therefore, to obtain more accurate loss rate, a method of strengthening packet loss measurement from the network intermediate point is proposed in this paper. Through constructing a series of heuristic rules and leveraging the binomial distribution principle, the proposed method realizes the compensation for the estimated loss rate. Also, experiment results show that although there is no increase in the proportion of accurate estimates, the compensation makes the majority of estimates closer to the accurate ones.

• 한국농공학회논문집
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• 제57권1호
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• pp.11-23
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• 2015

In this study the laboratory test for hydraulic conductivity and the seepage analysis with finite element method on measurement section of sea dike embankment were performed for the purpose of estimating the relative density of embankment from the measured pore water pressures, and both results of the test and the analysis were coupled with the method of estimating seepage blocking state with the hydraulic head loss rate in sea dike embankment. The relationship of void ratio vs hydraulic head loss rate was obtained by setting hydraulic conductivity as common ordinate on the relationships between the void ratio and the hydraulic conductivity and between the hydraulic conductivity and the hydraulic head loss rate. The void ratio on the segment between measuring points was calculated from the coupled relationship of the void ratio vs the hydraulic conductivity. The allowable upper and lower limits of hydraulic head loss rate and those of void ratio on the safety were generated from the coupled relationship between the laboratory compaction test and the sedimentation test. Current hydraulic head loss rate and void ratio were evaluated in the allowable range between upper and lower limits.

• Nuclear Engineering and Technology
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• 제46권1호
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• pp.39-46
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• 2014

A total loss of all heat sinks is considered a severe accident with a low probability of occurrence. Following a total loss of all heat sinks, the degasser/condenser relief valves (DCRV) become the sole means available for the depressurization of the primary heat transport system. If a nuclear power plant has a total loss of heat sinks accident, high-temperature steam and differential pressure between the primary heat transport system (PHTS) and the steam generator (SG) secondary side can cause a SG tube creep rupture. To protect the PHTS during a total loss of all heat sinks accident, a sufficient depressurization capability of the degasser/condenser relief valve and the SG tube integrity is very important. Therefore, an accurate estimation of the discharge through these valves is necessary to assess the impact of the PHTS overprotection and the SG tube integrity of the primary circuit. This paper describes the analysis of DCRV discharge capacity and the SG tube integrity under a total loss of all heat sink using the CATHENA code. It was found that the DCRV's discharge capacity is enough to protect the overpressure in the PHTS, and the SG tube integrity is maintained in a total loss of all heat accident.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 추계학술대회 논문집
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• pp.597-600
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• 2009

Sound transmission loss (TL) is experimently investigated on the multi-layered panel used for the floor of a tilting train. Measurement of the intensity transmission loss is performed according to ASTM E 2249-02. The floor structure consists of corrugated steel panel, glass wool, plywood and cover. On the corrugated steel panel, TL drop by local resonance is considered and the TL improvement effect by damping treatment is estimated. Total sound transmission loss of the entire floor structure is obtained and the contribution of each layer is examined.

• 한국환경과학회지
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• 제22권2호
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• pp.225-234
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• 2013

The relationship between debris flow and topographical factors is essential for the reliable estimation of soil loss. The objective of this paper is to estimate stability index and soil loss for assessing landsliding risk caused by debris flow. SIMAP and RUSLE are used to estimate stability index and soil loss, respectively. The landsliding risk area estimated by using SIMAP is found to be different from the large land area estimated by RUSLE. It is found that the spatial distribution of soil cover significantly influences landsliding risk area. Results also indicate that stability index and soil loss, estimated by soil cover factor, improve the assessment of landsliding risk.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.160-162
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• 1996

The estimation of AC losses is demanded for higher efficiency and stability in AC use of superconducting coils. Hysteresis loss occurred by a.c. transport current is called of self field loss, and it is major part of losses generated in a.c. superconducting wire in case of located in low external magnetic field as superconducting transformer with iron core, or in short twist pitch wire, multiply stacking cable. In this paper, we calculate self field loss of superconducting wire.

• 동력기계공학회지
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• 제5권3호
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• pp.48-55
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• 2001

In many applications. rubber components undergo dynamic stresses or deformations of fairly large magnitude. Since rubbers are not fully elastic, a part of the mechanical energy is converted into heat due to the hysteresis loss. Heat generation without adequate heat dissipation leads to heat build up. i. e. internal temperature rise. The purpose of this paper is to predict temperature rise caused by the hysteresis loss, in a rubber pad subjected to complex dynamic deformation. In this unsteady thermal analysis, the temperature distributions of track components are displayed in contour shapes and the temperature variations of some important nodes are represented graphically with respect to the running time of the tank.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.34-38
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• 2001

The purpose of this study is to estimate temporal soil loss change according to long-term land cover changes using GIS and RS. Revised USLE(Universal Soil Loss Equation) factors were made by using point rainfall data, DEM(Digital Elevation Model), soil map and land cover map. Past two decades land cover changes were traced by using Landsat MSS and TM data. Soil loss in 2000 increased $6.3\;kg/m^{2}/yr$ compared with that in 1983. This was mainly caused by the increased upland area.

• 상하수도학회지
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• 제23권1호
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• pp.107-112
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• 2009

This study was conducted for verification and systematization of estimation method about the headloss using CFD(Computational Fluid Dynamics). Head loss which happens between the inlet and outlet of in-line mixer can be a major factor for the design and construction. Also, this Case studies about the sensitivity related to the velocity in the piping system. As result, program's default calculation function was used to get each side's total pressure and the differential of each total pressure could be defined as head loss from in-line mixer. In the case of adopting pipe surface friction factor and geometry loss, Calculation residual can be much more reduced. It was found that residual of value between CFD method and field test ranged about 3 through 18 precent.

• Journal of Advanced Marine Engineering and Technology
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• 제24권5호
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• pp.42-51
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• 2000

The performances of the simple expansion, perforated tube, and conical-connector type as an exhaust muffler are shown in this study. Applying a model in which the method of four-pole parameter is used makes theoretical estimation of the insertion loss. Experiment is performed for the measurement of the insertion loss under four cases according to the variation of the tail pipe length. By comparing the theoretical prediction with the experimental results, the validity of the modeling using the method of four-pole parameter is verified. The personal computer simulation programs for the above mentioned theory on the muffler design have been developed and exhaust sound level measurements have been carried out for simple expansion muffler, conical-connector muffler, perforated tube mufflers and the combined type of conical-connector and simple expansion muffler. The measured results for attenuation characteristics of noise for each muffler are compared with the computed theoretical results to verity the confidence and applicable limits of the theoretical equation derived.