• Environmental Engineering Research
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• v.20 no.2
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• pp.155-161
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• 2015

Experimental research shows that the nitric oxides ($NO_X$) concentration track at the outlet of selective catalytic reduction (SCR) catalyst with a transient variation of Adblue dosage has a time delay and it features a characteristic of resistance-capacitance (RC). The phenomenon brings obstacles to get the simultaneously $NO_X$ expected to be reduced and equi-molar ammonia available to SCR reaction, which finally inhibits $NO_X$ conversion efficiency. Generally, engine loads change frequently, which triggers a rapid changing of Adblue dosage, and it aggravates the air quality that are caused by $NO_X$ emission and ammonia slip. In order to increase the conversion efficiency of $NO_X$ and avoid secondary pollution, the paper gives a comprehensive analysis of the SCR system and tells readers the key factors that affect time delay and RC characteristics. Accordingly, a map of time delay is established and a solution method for time constant and proportional constant is carried out. Finally, the paper accurately describes the input-output state relation of SCR system by using "variable RC model with time delay". The model can be used for a real-time correction of Adblue dosage, which can increase the conversion efficiency of $NO_X$ in SCR system and avoid secondary pollution forming. Obviously, the results of the work discover an avenue for the SCR control strategy.

• Journal of Construction Engineering and Project Management
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• v.7 no.3
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• pp.1-14
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• 2017

Delay claim should actually be supported by a set of proper information so that the contractors could prove their validity. The so-called information should be able to clarify the relationship between delay events and how they impact on the whole project. Therefore, exploiting an integrated system by people who are involved in construction business would certainly prove helpful. In the present study, delay analysis methods have been investigated along with selecting a relatively comprehensive method which has been modified, and eventually, a novel model and its required modules have been proposed for evaluating delay claims. The suggested integrated model is formed to identify delayed events, to classify delays, to measure the impacts of delays on the project scheduling, and finally to estimate the damages which were caused by those so-called delays. A decision support system (DSS) model which is related to the integrated system is actually extracted from Iran's general contract conditions, that is, 4311 magazine (equivalent to red FIDIC book). It is then programmed and coded by C# program. This DSS model can be used as an input of Easy Plan program. In addition, at the end of this research, the coded DSS has been used along with the so-called program so that a modified and developed model could be generated.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.7
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• pp.602-617
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• 1990

In this paper, we analyze the performance of D-channel access protocol at the S-reference point for the ISDN user network interface recommended by CCITT. For the case of multipoint access to D-channel, a queueing model of D-channel access protocol is proposed. The delay is analyzed by decomposing it into waiting queue delay and contention delay. The contention delay is decomposed further into vain contention delay and pure contention delay so the analysis of the priority queueing system with symmetrical and asymmetrical arrival rates may be applied. The numerical results obtained are compared with the results of the single station queueing system served by the non-preemptive priority.

• Proceedings of the IEEK Conference
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• 2001.06c
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• pp.93-96
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• 2001

In this paper, we propose a delay-constrained retransmission method to control packet error or loss in common internet. The Delay Regulator(or Jitter Buffer) which is used to control errors caused by unreliable UDP connection, stores received data packets fDr a small amount of time to prevent network jitter from affecting display quality, which causes constant delay. In this paper, we propose a retransmission method to increase efficiency of ARQ(Automatic Repeat reQuest) by using characteristic of delay regulator.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.113-116
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• 2000

The effect due to group delay and non linear characteristics in high speed data satellite channel was represented in this paper. Based on the modeling of group delay and non linear characteristics the performance was analyzed in ka band satellite channel. The group delay and non-linear characteristics in high speed data transmission severely affect the system performance. The more Eb/No is required to satisfy the required system performance. The optimum operating points of HDR satellite transmission system are implemented by considering analyzed results for channel characteristics

• Journal of applied mathematics & informatics
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• v.8 no.1
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• pp.297-303
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• 2001

In this paper, the problem of the stability analysis for a class of linear neutral systems with time-varying delay is investigated. Using the Lyapunov method, a delay-dependent sufficient condition for asymptotic stability of the systems in terms of linear matrix inequalities (LMIs) is presented. The LMIs can be easily solved by various convex optimization algorithms.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.989-993
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• 2009

Wireless LAN(WLAN) is a rather mature communication technology connecting mobile terminals. IEEE 802.11 is a representative protocol among WLAN technologies. With the rising popularity of delay-sensitive real-time multimedia applications(video, voice and data) in IEEE 802.11 wireless LAN, it is important to study the MAC layer delay performance of WLANs. In this paper, performance for packet delay that recently have been proposed schemes is analysed in wireless LAN and proved performance results via simulation.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1512-1515
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• 1987

The buffer circuit having minimum delay time is designed and analyzed in this paper. Considering the parasitic components of the MOS transistor, the optimal transistor size ratio between the individual buffer stages is presented. This paper's result is better than that of the Mead and Conway's analysis [1] with respect to both delay time and total area that buffer occupies.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.59.5-59
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• 2002

In this paper, we present a robust controller design method that can not only deal with the constant time delay plant but also an uncertain time delay one. For a constant time delay plant. The proposed DTC can independently adjust the set response and the disturbance response without any stability constraint. And in the uncertain time delay case, one can process the control design step with uncertainty norm bound. To verify real effectiveness, theoretical analysis and simulation results are given.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.845-849
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• 1992

The disturbance and time delay can often cause a significant error in the estimation of trajectory of a underwater vehicle. The time delay considered in this study is due to the delayed rudder response to the rudder input from the guidance control part. The simulation tests are performed on maneuver with constant rudder angle, zigzag maneuver, dive-climb maneuver, and corridor pattern maneuver. The results are compared with those of without delay cases.