• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.6
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• pp.2463-2482
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• 2016

Cloud services are often provisioned to their customers using user-friendly web browsers with flexible and rich plug-in environments. Delay is one of the fundamental performance metrics of these web-based services. Commonly-used network measurement tools usually only measure network delay and it may be difficult to infer the web-delay performance using only network layer measurement approaches. In this paper, we propose to evaluate the application layer delay in a browser-based network measurement platform using engineered scripts. We conducted a delay measurement study using instrumented scripts in the proposed browser-based measurement platform. Our investigation included a comparison study of three browser-scripting delay measurement methods, including Java applet, JSP and Flash ActionScript. We developed a browser-based delay measurement testbed over the Internet so that different delay measurement tools could be evaluated in the same real network environment including typical Internet paths and the Baidu cloud. We also decomposed the components of the end-to-end delay process of the above measurements to reveal the difference and relationship between the network-layer delay and the application-layer delay. Our measurement results characterize the stochastic properties of the application-layer delay over real Internet paths, and how these properties vary from the underlying network layer delay. This browser-scripting measurement approach can be easily deployed on different cloud service platforms to inspect their application-layer delay performance between end clients and the cloud platforms. Our measurement results may provide insights into designing new cloud services with enhanced quality-of-experience perceived by cloud users.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.202-205
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• 1988

Several sufficient condition which guarantee the stability of linear state delay systems are derived. And the delay margin which guarantees the stability of the delay systems are presented.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.131-136
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• 2006

In constructing projects, there exist various kinds of work interferences, which cause a delay of the outset and completion of planned schedule because of some attributions, such as variability, uncertainty and complexity. and so schedule delay has been treated as a natural phenomenon. To reduce or prevent the schedule delay, a constant confirmation of schedule delay and a preparation of counter plans for finding out the cause structure of schedule delay should have been done. However, all this time the research has been mostly done on the calculation method or claim cases of schedule delay. Moreover, the analysis method did not consider the trait, which cause the schedule delay, in constructing projects. This paper restricts the range of the cause analysis of schedule delay to the field of site management in the projects and divides the cause structure of schedule delay into the cause objects and cause attributes of schedule delay according to the input elements. The system of classifying causes of schedule delay is examined by interviews with experts and questionnaire. Additionally, this paper analyzes the attributes of cause attributes and cause subjects and presents the analysis method and procedure of schedule delay with the application of VSM.

• Structural Engineering and Mechanics
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• v.40 no.3
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• pp.431-451
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• 2011

Time delay inevitably exists in active control systems, and it may cause the degradation of control efficiency or instability of the systems. So time delay needs to be compensated in control design in order to eliminate its negative effect on control efficiency. Today time delay in linear systems has been more studied and some treating methods had been worked out. However, there are few treating methods for time delay in nonlinear systems. In this paper, an active controller for a nonlinear and hysteretic building structure with time delay is studied. The nonlinear and hysteretic behavior of the system is illustrated by the Bouc-Wen model. By specific transformation and augmentation of state parameters, the motion equation of the system with explicit time delay is transformed into the standard state space representation without any explicit time delay. Then the fourth-order Runge-Kutta method and instantaneous optimal control method are applied to the controller design with time delay. Finally, numerical simulations and comparisons of an eight-story building using the proposed time-delay controller are carried out. Simulation results indicate that the control performance will deteriorate if time delay is not taken into account in the control design. The simulations also prove the proposed time delay controller in this paper can not only effectively compensate time delay to get better control effectiveness, but also work well with both small and large time delay problems.

• Korean Journal of Childcare and Education
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• v.1 no.1
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• pp.167-189
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• 2005

The purpose of this study was to examine the relationships among delay gratification, delay strategy, and parents' child-rearing attitude. The participants of the study were 62, 18-36 month old infants, who demonstrated individual differences in the level of delay gratification and their mothers. The instruments of the study were infant's delay gratification and delay strategy were assessed by Mischele(1974) and the parents' responded to the parents' child-rearing attitude(Cho et al., 1999). Data were collected by menas of conducting observations on infants in experimental settings and completing questionnaires with mothers. The results of this study were as follows: 1. The delay gratification of infants differed accordingly to their age. Older infants displayed increased time in showing their delay gratification, while younger infants relatively exhibited shortened time. There was no significant difference in infants' sex and the order of the birth. 2. Following the age factor, the distraction strategy in the delay strategy played a significant difference to infants. Older infants required a frequent use of the distraction strategy in comparison to younger infants. 3. The previous two factors - delay gratification and distraction strategy-showed a positive relationship. 4. The delay gratification was significantly influenced by infants' age, parents' attitude, direct facing strategy, and infants' distraction strategy. However, the delay gratification was insignificantly accounted for by infants' sex.

• Korean Journal of Child Studies
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• v.29 no.3
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• pp.339-356
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• 2008

Participants in this study on preschool children's ability to delay gratification were 132 4- to 5 year-old children and their mothers from 6 daycare centers. Mothers completed questionnaires reporting their parenting style, their child's ability to delay gratification, and child's temperament. Children participated in the real and hypothetical settings of the delay of gratification experiment. Data was analyzed by t-test, F-test, correlation and discrimination analysis. Results were that (1) 43% of preschoolers passed the delay of gratification experiment. (2) Older children were more able to delay gratification than younger children. (3) Children's rewards choices in the real setting correlated with their rewards choices in the hypothetical situation of delay of gratification. (4) Children's ability to delay gratification was influenced by their motor intelligence.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.119.3-119
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• 2001

When building a network-based real-time control system, a network-induced delay time should be surly considered for real time schedulability to be guaranteed. The network delay time on end-to-end communication has been analyzed theoretically and modeled mathematically from many previous works. There also exist any other delay element not considered before. In this paper, the remote feedback control system using the CAN protocol is proposed to control three axes´ manipulator arm and the application layer of CAN is modeled to analyze the delay elements defined by three types of time delay: Software delay time, Controller delay time, and Access delay time, in details. The analyzed results are used as an important component to determine PID gains of the proposed system. The effect of the delay time on the control performance is evaluated by com paring the response characteristics of the control system through simulation.

• Journal of the Korea Institute of Building Construction
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• v.9 no.1
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• pp.89-94
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• 2009

A study was performed the analysis for the schedule delay of the public housing. To perform this study, the first study existing research literature on the cause of the schedule delay was considered. The based on existing study, this study selected the cause of schedule delay. For check of the schedule delay, this study was compared the monthly schedule and the work diary. Survey was conducted for using the selected cause of schedule delay. And the importance was calculated for using the AHP method. In a case site, the cause of the schedule delay was analyzed. The last, the delay cause was presented the map of cause of effect the based on the delay cause of a case site.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.520-529
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• 2007

Apportioning responsibilities of concurrent delay to the owner and the contractor is a difficult task, due to the sophisticate nature both in the schedule and in the factors that cause the delay. This research attempts to develop a simplified yet systematic approach that can be used for a fair apportionment of concurrent delay. A concurrent delay is defined herein as when the contractor and the owner have both caused independent critical path delays during the same approximate time period. Incorporating the concepts of windows analysis and critical path method (CPM), the developed approach has three "windowing of delay" steps to quickly apportion the delay in each of these windows, and a fourth step to sum up those apportioned delays to obtain each party's final responsibilities. This developed approach is found to be simple and effective at this stage; it will be tested against real cases in the near future.

• Proceedings of the IEEK Conference
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• 2000.11b
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• pp.87-90
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• 2000

This paper describes a register-controlled symmetrical delay-locked-loop (DLL) using hybrid delay line for use in a high frequency double-data-rate DRAM. The proposed DLL uses a hybrid delay line which can cover two-step delays(coarse/fine delay) by one delay element. The DLL dissipate less power than a conventional dual-loop DLL which use a coarse and a fine delay element and control separately. Additionally, this DLL not only achieves small phase resolution compared to the conventional digital DLL's when it is locked but it also has a great simple delay line compared to a complex dual-loop DLL.