• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권6호
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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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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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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.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2006년도 정기학술발표대회 논문집
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• pp.131-136
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• 2006

작업의 지연을 줄이거나 예방하기 위해서는 작업지연상황을 지속적으로 확인하여 작업지연을 야기하는 원인을 찾아내고 대책을 세워야 한다. 건설 프로젝트는 동일한 조건하에서도 주변 환경에 따라 결과 값이 다르게 나타나는 일회성이 강한 분야 중에 하나이다. 그래서 지금까지 이루어진 선행연구들은 작업지연기간 산정방법 또는 작업지연의 클레임 사례에 관한 연구와 프로젝트 종료 후 결과에 의한 원인을 제시한 것이 대부분이다. 따라서 공사 진행 중에 발생하는 작업지연에 대해 체계적으로 활용할 수 있는 분석방법과 절차가 필요하다. 본 연구는 작업지연 원인분석 범위를 프로젝트내의 현장관리 분야로 국한하고 작업의 투입요소에 의한 분석과 VSM을 활용한 분석으로 나눴다. 건설업에 적합한 원인분석 방법을 제안하기 위해 기존에 활용되고 있는 분석방법의 특징을 분석하고 건설업의 특징을 분석하여 건설업에 활용이 적합한 방법을 도출하고 절차를 제안하였다.

• Structural Engineering and Mechanics
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• 제40권3호
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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.

• 한국보육지원학회지
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• 제1권1호
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• pp.167-189
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• 2005

본 연구에서는 영아의 만족지연능력과 만족지연전략 및 어머니의 통제성간의 관계를 알아보았다. 연구대상은 18-36개월의 영아였으며 만족지연능력 측정 실험은 Mischel(1974)이 고안한 자기 만족지연 실험을 Rha(1999)가 연령에 맞게 번안한 것을 사용하였다. 만족지연능력에 사용되는 전략으로는 직접응시 전략과 주의분산 전략으로 분류하여 관찰하였으며 어머니의 양육방식은 조복희, 이진숙, 이홍숙 그리고 권희경(1999)에 의해 개발된 척도의 일부인 통제 13문항을 발췌하여 사용하였다. 연구결과 영아의 월령이 증가함에 따라 만족지연능력이 증가하며, 영아가 사용하는 만족지연전략은 월령이 높아질수록 주의분산전략을 더 많이 사용하는 것으로 나타났다. 또한 영아의 월령, 만족지연 전략인 직접응시 전략과 주의분산 전략은 영아의 만족지연능력에 유의미한 영향을 주었다.

• 아동학회지
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• 제29권3호
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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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• 제어로봇시스템학회 2001년도 ICCAS
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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.

• 한국건축시공학회지
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• 제9권1호
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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.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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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.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(2)
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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.