• The Journal of Korean Institute of Communications and Information Sciences
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• v.11 no.1
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• pp.16-24
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• 1986

The queueing delay and the response time of model of the buffer insertion LAN have been derived and its performance has been analyzed in terms of the throughput rate-response time characteristic. The results show that the response time can be improved by increasing the medium data rate, and that it can be reduced by 0.7 msec by transmitting the acknowledgement signal at the network interface unit(NIU) rather than at the hose, when the channel utilization is approximately 0.8. Also, implementation of the buffer insertion protocol has been studied.

• Convergence Security Journal
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• v.13 no.1
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• pp.3-10
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• 2013

In this paper, reliability software model considering fault detection rate based on observations from the process of software product testing was studied. Adding new fault probability using the S-shaped distribution model that is widely used in the field of reliability problems presented. When correcting or modifying the software, finite failure non-homogeneous Poisson process model was used. In a software failure data analysis considering the time-dependent fault detection rate, the parameters estimation using maximum likelihood estimation of failure time data and reliability make out.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.15-20
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• 2000

The studies of swine wastewater treatment aim to development of process using soil microorganism. Removal rate of swine wastewater containing organic matter was 99 percent in case of high loading rate. Microorganism was devoted to improve the treatment efficiency of the process. According to the result obtained from biological treatment of high loading rate swine wastewater. Hydraulic retention time was 2.3 days in unit process of biological phosphorus removal. BO $D_{rm}$ / $P_{rm}$ ratio was 1122 in room temperature anaerobic process and 355.6 in mesophilic anaerobic process. And then phosphorus removal rate mesophilic anaerobic process was 3 time as much as than room temperature acaerobic process.

• Journal of Satellite, Information and Communications
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• v.9 no.4
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• pp.13-15
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• 2014

At frequencies above 10 GHz, rain is a dominant propagation phenomenon on satellite link attenuation. The prediction of rain attenuation is based on the point rainfall rate for 0.01 % of an average year with one minute integration time. Most of available rain data have been measured with 60 minutes integration time, and many researchers have been studying on converting the rainfall rate data from various integration times to one minute integration time. This paper proposes a new Multiple Regression model for the conversion, and the proposed schemes show better performance than the existing schemes.

• Transactions of Materials Processing
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• v.6 no.2
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• pp.102-109
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• 1997

The multistage deformation and stress relaxation were carried out to investigate the strain induced precipitation by torsion tests in the range of 1000~80$0^{\circ}C$, 0.05~5/sec for V-microalloyed steel. The starting temperature and time for the initiation of precipitation were determined by stress relaxation tests. The distribution of precipitates increased, as the strain rate increased and the mean size of precipitates was found to be about 10~30nm. The precipitation starting time$(P_s)$ decreased with increasing strain rate and the amount of pre-strain. The effect of deformation conditions on the no-recrystallization temperature$(T_nr)$ was also determined in the multistage deformation. $T_nr$ Tnr decreased with increasing the strain and strain rate. In the controlled rolling simulation, grain refinement and precipitation hardening effects could be achieved by the alternative large pass strain at the latter half pass stage under the condition of low temperature and high strain rate.

• Journal of ILASS-Korea
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• v.25 no.3
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• pp.132-138
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• 2020

N₂O is hazardous atmosphere pollution matter which can damage the ozone layer and cause green house effect. There are many other nitrogen oxide emission control but N₂O has no its particular method. Preventing further environmental pollution and global warming, it is essential to control N₂O emission from industrial machines. In this study, the thermal decomposition experiment of N₂O gas mixture is conducted by using cylindrical reactor to figure out N₂O reduction and NO formation. And CHEMKIN calculation is conducted to figure out reaction rate and mechanism. Residence time of the N₂O gas in the reactor is set as experimental variable to imitate real SNCR system. As a result, most of the nitrogen components are converted into N2. Reaction rate of the N₂O gas decreases with N₂O emitted concentration. At 800℃ and 900℃, N₂O reduction variance and NO concentration are increased with residence time and temperature. However, at 1000℃, N₂O reduction variance and NO concentration are deceased in 40s due to forward reaction rate diminished and reverse reaction rate appeared.

• Computers and Concrete
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• v.22 no.3
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• pp.291-303
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• 2018

As the concept of "sponge city" is proposed, the pervious concrete for permeable pavement has been widely used in pavement construction. This paper aims at investigating the dynamic behavior and energy evolution of pervious concrete under impact loading. The dynamic compression and split tests are performed on pervious concrete by using split Hopkinson pressure bar equipment. The failure criterion on the basis of incubation time concept is used to analyze the dynamic failure. It is demonstrated that the pervious concrete is of a strain rate sensitive material. Under high strain rate loading, the dynamic strength increases while the time to failure approximately decreases linearly as the strain rate increases. The predicted dynamic compressive and split tensile strengths based on the failure criterion are in accordance with the experimental results. The total damage energy is found to increase with the increasing of strain rate, which means that more energy is needed to produce irreversible damage as loading rate increases. The fractal dimensions are observed increases with the increasing of impact loading rate.

• Journal of Yeungnam Medical Science
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• v.3 no.1
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• pp.81-85
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• 1986

Observation of changing pattern of blood pressure and pulse rate of enflurane anesthesia for 200 cases operations, performed during the past 4 years(1983~1986) in Yeungnam University Hospital have been evaluated clinically. In order to observe the influence of enflurane upon the blood pressure and pulse rate during general anesthesia, the authors prepared a formula, expressing changing of blood pressure and pulse rate by time series and analyzed the types and distribution pattern in the experiment. The results obtained were as follows : 1. Blood pressure and pulse rate were increased at the time of intubation. 2. Generally, blood pressure and pulse rate were increased at the time of intubation and then stabilized withing 20 minutes. 3. Most common patterns were identified, ADEE type was 73~74%, Which is most common type and AEEE type was about 40%.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.180-181
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• 2017

This study aims to analyze the high strength mortar's fundamental properties and autogenous shrinkage properties by taking into consideration the result of the previous study in which it was found that ERBO(Biodiesel) exercises greatest effect on the expansion effect of mortar, and changing the time and rate of mixing the ERBO. A total of five levels were set as experimental variables: the three levels of the rate of ERBO, 0, 0.5, 1.0%, and the two levels of the time of mixing the ERBO: first, adding the ERBO with the mixing water and mixing it before, and second, mixing it after the mortar is completely mixed. It was found that the rate of length change decreased as the rate of ERBO increased, and the rate of length change was lower when the ERBO was mixed sooner.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.11
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• pp.548-556
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• 2005

Reliability evaluation of power distribution system is very important to both power utilities and customers. It present the probabilistic number and duration of interruption such as failure rate, SATDI, SAIFI, and CAIDI. However, it has a fatal weakness at reliability index because of accuracy of failure rate. In this paper, the Time-varying Failure Rate(TFR) of power distribution system equipment is extracted from the recorded failure data of KEPCO(Korea Electric Power Corporation) in Korea. For TFR extraction, it is used that the fault data accumulated by KEPCO during 10 years. The TFR is approximated to bathtub curve using the exponential(random failure) and Weibull(aging failure) distribution function. In addition, Kaplan-Meier estimation is applied to TFR extraction because of incomplete failure data of KEPCO. Finally, Probability plot and regression analysis is applied. It is presented that the extracted TFR is more effective and useful than Mean Failure Rate(MfR) through the comparison between TFR and MFR