ON THE TRANSIENT DEPARTURE PROCESS OF M^x/G/1 QUEUEING SYSTEM WITH SINGLE SERVER VACATION

This paper studies the transient departure process of M^x/G/1 queueing system with single server vacation. We present a simple probability decomposition method to derive the expected number of departures occurring in finite time interval from any initial state and the asymptotic expansion of the expected number. Especially, we derive some more practical results for some special cases.     

THE M/M/c QUEUE WITH （e,d） SETUP TIME

The authors present a new queueing model with （e, d） setup time. Using the quasi-birth-and-death process and matrix-geometric method, the authors obtain the stationary distribution of queue length and the LST of waiting time of a customer in the system. Furthermore, the conditional stochastic decomposition results of queue length and waiting time are given.     

Weighted <Emphasis Type="Italic">L</Emphasis><Superscript>2</Superscript>-estimates of solutions for damped wave equations with variable coefficients

The authors establish weighted L²-estimates of solutions for the damped wave equations with variable coefficients u _tt ? divA(x)?u+au _t = 0 in ? ⁿ under the assumption a(x) ≥ a₀[1+ρ(x)]^?l, where a₀ > 0, l < 1, ρ(x) is the distance function of the metric g = A^?1(x) on ? ⁿ . The authors show that these weighted L²-estimates are closely related to the geometrical properties of the metric g = A^?1(x).     

ON APPROXIMATION BY REPRODUCING KERNEL SPACES IN WEIGHTED L^p SPACES

In this paper, we investigate the order of approximation by reproducing kernel spaces on （-1, 1） in weighted L^p spaces. We first restate the translation network from the view of reproducing kernel spaces and then construct a sequence of approximating operators with the help of Jacobi orthogonal polynomials, with which we establish a kind of Jackson inequality to describe the error estimate. Finally, The results are used to discuss an approximation problem arising from learning theory.     

An FE-Inexact Heterogeneous ADMM for Elliptic Optimal Control Problems with <Emphasis Type="Italic">L</Emphasis><Superscript>1</Superscript>-Control Cost

Elliptic PDE-constrained optimal control problems with L¹-control cost (L¹-EOCP) are considered. To solve L¹-EOCP, the primal-dual active set (PDAS) method, which is a special semismooth Newton (SSN) method, used to be a priority. However, in general solving Newton equations is expensive. Motivated by the success of alternating direction method of multipliers (ADMM), we consider extending the ADMM to L¹-EOCP. To discretize L¹-EOCP, the piecewise linear finite element (FE) is considered. However, different from the finite dimensional l1-norm, the discretized L¹-norm does not have a decoupled form. To overcome this difficulty, an effective approach is utilizing nodal quadrature formulas to approximately discretize the L¹-norm and L²-norm. It is proved that these approximation steps will not change the order of error estimates. To solve the discretized problem, an inexact heterogeneous ADMM (ihADMM) is proposed. Different from the classical ADMM, the ihADMM adopts two different weighted inner products to define the augmented Lagrangian function in two subproblems, respectively. Benefiting from such different weighted techniques, two subproblems of ihADMM can be efficiently implemented. Furthermore, theoretical results on the global convergence as well as the iteration complexity results o(1/k) for ihADMM are given. In order to obtain more accurate solution, a two-phase strategy is also presented, in which the primal-dual active set (PDAS) method is used as a postprocessor of the ihADMM. Numerical results not only confirm error estimates, but also show that the ihADMM and the two-phase strategy are highly efficient.     

PERSPECTIVES ON URBAN WATER INFRASTRUCTURE IN CHINA FOR THE 21^ST C0ENTURY： SDMUWEIC MODEL

Based on system dynamics approach, SDMUWEIC model is developed in order to evaluatefuture dynamics of urban water infrastructure development in China. Firstly, this paper presents thebasic structure and characteristics of the model, focusing on water infrastructure‘s dynamicrelationships with population increase, economic development, water resources shortage and waterconservation practices. Secondly, model veracity and robustness tests based on behavior reproductionand uncertainty analyses are illustrated. Thirdly, based on the model, future pattems of China‘s urbanwater infrastructure investment requirements are simulated, and effectiveness of two different policyscenarios are evaluated. Finally, conclusion,; and policy implications are drawn, allowing insights intoChina‘s sustainable water infrastructure policies and managements.     

PART 2: Critical Systemic Praxis to Address Fixed and Fluid Identity and Politics<Superscript>1</Superscript> at the Local,National and International Level

This paper argues for a model of systemic governance that can take account of diverse identities and political positions (Deleuze and Guattari in Bogue, 1989). Participatory Action Research can assist in working with diverse viewpoints when managing and making policy decisions across many organizations locally, nationally and internationally. Understanding the point of view of ‘the other’ and the recursive nature of identity and politics is the first step towards sustainable governance. Enabling multiple viewpoints to be heard is both an idealistic and sustainable end and a means to manage risk. Accountability needs to ‘sweep in’ and ‘unfold’ (Churchman, 1979a,b, 1982) social, cultural, economic and environmental factors (adapting Elkington, 1997, drawing on Banathy, 1996, 2000; Laszlo, 1991; Laszlo, and Laszlo, 2004). Participatory governance needs to address questions about fixed and fluid politics and identity. These questions address cultural norms, bonds and boundaries (Elias and Lichterman, 2003) to guide reflection on cases that strive to achieve accountability. Experiential learning through participatory action research with the most marginalised in society and listening to significant others (whose systemic praxis) is the basis for the theory on systemic governance.¹Paper is drawn from forthcoming book entitled: “Systemic Governance: Working and re-working the conceptual and geographical boundaries of governance and international relations” (2005) and parts of the paper were presented at the 49th Annual Conference of the International Systems Sciences Asilomar 2004. A more detailed version of the case study on the hijab has been submitted for consideration as a publication on human rights and governance to Systems Research and Behavioural Science October 2004. References to Churchman’s work have also been made in Critical Systemic Praxis for Social and Environmental Justice (2003)Kluwer.     

Reflection-in-and-on-Action in Participatory Action Research: Toward Assessment <Emphasis Type=Italic>for </Emphasis>Learning

This article is about the use of oral assessment for learning and was based on a reflection-in-and-on-action approach within a participatory action research framework. The purpose of this paper was to argue for the incorporation of oral assessment in tertiary science as a fair, reliable and valid approach to assessment. This study found that the interactive nature of the oral assessments led to improved learning of content for learners from their peers and assessors. Assessors too learnt about their students as individuals, their study habits and critiqued their teaching from the oral assessments. They also learned from their co-assessors. Valuable lessons were learned for collaborative team teaching and assessing for the benefit of assessors and learners alike. This study also found that action research afforded the assessors a new way of doing things empowering them to conduct research in their own classrooms, with their colleagues and their learners.     

<Emphasis Type=Italic>Geom/G</Emphasis><Subscript>1</Subscript>, <Emphasis Type=Italic>G</Emphasis><Subscript>2</Subscript>/1/1 repairable Erlang loss system with catastrophe and second optional service

This paper studies a single server discrete-time Erlang loss system with Bernoulli arrival process and no waiting space. The server in the system is assumed to provide two different types of services, namely essential and optional services, to the customer. During the operation of the system, the arrival of the catastrophe will break the system down and simultaneously induce customer to leave the system immediately. Using a new type discrete supplementary variable technique, the authors obtain some performance characteristics of the queueing system, including the steady-state availability and failure frequency of the system, the steady-state probabilities for the server being idle, busy, breakdown and the loss probability of the system etc. Finally, by the numerical examples, the authors study the influence of the system parameters on several performance measures.     

Construction of one-Lee weight and two-Lee weight codes over F<Subscript><Emphasis Type="Italic">p</Emphasis></Subscript> + <Emphasis Type="Italic">v</Emphasis>F<Subscript><Emphasis Type="Italic">p</Emphasis></Subscript>

This paper is devoted to the construction of one-Lee weight codes and two-Lee weight codes over F _p + vF _p (v ² = v) with type \({p^{2{k_1}}}{p^{{k_2}}}{p^{{k_3}}}\) based on two different distance-preserving Gray maps from ((F _p + vF _p ) ⁿ , Lee weight) to (F _p ²ⁿ , Hamming weight), where p is a prime. Moreover, the authors prove that the obtained two-Lee weight codes are projective only when p = 2.     

A perishable inventory system with service facilities, <Emphasis Type="Italic">MAP</Emphasis> arrivals and <Emphasis Type="Italic">PH</Emphasis> — Service times

We consider a continuous review perishable （s,S） inventory system with a service facility consisting of a waiting hall of finite capacity and a single server. We assume two types of customers, ordinary and negative, arrive according to a Markovian Arrival Process （MAP）. An ordinary customer joins the queue and a negative customer instead of joining the queue removes one ordinary customer from the queue. The removal rule adopted in this paper is RCE （removal of a customer from the end）. The individual customer＇s unit demand is satisfied after a random time of service which is assumed to have a phase-type distribution. The life time of each item and the lead time of the reorders have been assumed to be independent exponential distributions. The joint probability distribution of the number of customers in the system and the inventory level is obtained for the steady state case. Various stationary system performance measures are computed and the total expected cost rate is calculated. The results are illustrated numerically.     

The structure of departure process and optimal control strategy <Emphasis Type="Italic">N</Emphasis>* for <Emphasis Type="Italic">Geo/G</Emphasis>/1 discrete-time queue with multiple server vacations and Min(<Emphasis Type="Italic">N,V</Emphasis>)-Policy

This paper considers the departure process and the optimal control strategy for a discretetime Geo/G/1 queueing model in which the system operates under the control of multiple server vacations and Min(N, V)-policy. Using the law of total probability decomposition, the renewal theory and the probability generating function technique, the transient and the steady-state probabilities that the server is busy at any epoch n⁺ are derived. The authors also obtain the explicit expression of the probability generating function for the expected number of departures occurring in the time interval (0⁺, n⁺] from any initial state. Meanwhile, the relationship among departure process, server’s state process and service renewal process in server busy period is found, which shows the special structure of departure process. Especially, some corresponding results of departure process for special discrete-time queues are directly gained by our results. Furthermore, the approximate expansion for calculating the expected number of departures is presented. In addition, some other important performance measures, including the expected length of server busy period, server’s actual vacation period and busy cycle period etc., are analyzed. Finally, some numerical results are provided to determine the optimum value N* for minimizing the system cost under a given cost structure.     

Strong approximation method and the (functional) law of iterated logarithm for <Emphasis Type="Italic">GI</Emphasis>/<Emphasis Type="Italic">G</Emphasis>/1 queue

In this paper, a unified method based on the strong approximation (SA) of renewal process (RP) is developed for the law of the iterated logarithm (LIL) and the functional LIL (FLIL), which quantify the magnitude of the asymptotic rate of the increasing variability around the mean value of the RP in numerical and functional forms respectively. For the GI/G/1 queue, the method provides a complete analysis for both the LIL and the FLIL limits for four performance functions: The queue length, workload, busy time and idle time processes, covering three regimes divided by the traffic intensity.     

ELIMINATION IN WEYI ALGEBRA AND q-IDENTITIES

In this paper, the following are introduced briefly： the basic concept of q-proper-hypergeometric; an algorithmic proof theory for q-proper-hypergeometric identities; and elimination in the non- commutative Weyl algebra. We give an algorithm for proving the single-variable q-proper-hypergeometric identities that is based on Zeilberger＇s approach and the elimination in Weyl algebra. Finally, we test several examples that have been proven by D. Zeilberger and H. Will using the WZ-pair method and Gosper algorithm.     

The equivalent representation of the breadth-one <Emphasis Type="Italic">D</Emphasis>-invariant polynomial subspace and its discretization

This paper demonstrates the equivalence of two classes of D-invariant polynomial subspaces, i.e., these two classes of subspaces are different representations of the breadth-one D-invariant subspace. Moreover, the authors solve the discrete approximation problem in ideal interpolation for the breadth-one D-invariant subspace. Namely, the authors find the points, such that the limiting space of the evaluation functionals at these points is the functional space induced by the given D-invariant subspace, as the evaluation points all coalesce at one point.     

Queue size distribution of Geo/G/1 queue under the Min(<Emphasis Type="Italic">N,D</Emphasis>)-policy

This paper considers a discrete-time Geo/G/1 queue under the Min(N,D)-policy in which the idle server resumes its service if either N customers accumulate in the system or the total backlog of the service times of the waiting customers exceeds D, whichever occurs first (Min(N,D)-policy). By using renewal process theory and total probability decomposition technique, the authors study the transient and equilibrium properties of the queue length from the beginning of the arbitrary initial state, and obtain both the recursive expression of the z-transformation of the transient queue length distribution and the recursive formula for calculating the steady state queue length at arbitrary time epoch n ⁺. Meanwhile, the authors obtain the explicit expressions of the additional queue length distribution. Furthermore, the important relations between the steady state queue length distributions at different time epochs n ^-, n and n ⁺ are also reported. Finally, the authors give numerical examples to illustrate the effect of system parameters on the steady state queue length distribution, and also show from numerical results that the expressions of the steady state queue length distribution is important in the system capacity design.     

<Emphasis Type="Bold">An Engineering View for Social Systems: Agency as an Operational Principle for Designing Higher Education Access Policies</Emphasis>

Access to higher education (HE) has been a persistent concern for governments, practitioners and researchers. Access to HE has been widely studied from scientific perspectives that have focussed on the factors that contribute to the problem; however, authors have highlighted the need for systemic and design perspectives on education systems. The need to connect research with policy remains one of the most challenging issues for education researchers. In view of this gap, this paper argues that engineering thinking and methods represent an opportunity for the design of HE access policies because engineering rationality (distinct from scientific rationalities) matches the concerns and goals of any policymaking attempt. Engineers design artefacts to meet particular goals. These artefacts are artificial systems, tangible or intangible, such as hammers, bridges or whole organizations, which are designed in particular contexts to meet precise goals. Policies for access to HE are good examples of artefacts that seek to fulfil specific needs under concrete constraints inherent to a country or region. More specifically, HE systems are social systems; in other words, they are created and recreated by the interactions and decisions of diverse actors. Hence, to change, redesign or improve such types of systems involves engineering their very interactions that are the outcomes of institutional and human actions. In particular, engineering design requires operational principles. Thus, we propose agency as a fundamental design concept for the improvement of HE systems, which opens new possibilities for a distinct type of policy-making that takes excellent advantage of what engineering can offer, while at the same time expanding on traditional expectations for engineering.     

GENERALIZED p-VALUES AND GENERALIZED CONFIDENCE INTERVALS FOR VARIANCE COMPONENTS IN GENERAL RANDOM EFFECT MODEL WITH BALANCED DATA

Various random models with balanced data that are relevant for analyzing practical test data are described, along with several hypothesis testing and interval estimation problems concerning variance components. In this paper, we mainly consider these problems in general random effect model with balanced data. Exact tests and confidence intervals for a single variance component corresponding to random effect are developed by using generalized p-values and generalized confidence intervals. The resulting procedures are easy to compute and are applicable to small samples. Exact tests and confidence intervals are also established for comparing the random-effects variance components and the sum of random-effects variance components in two independent general random effect models with balanced data. Furthermore, we investigate the statistical properties of the resulting tests. Finally, some simulation results on the type Ⅰ error probability and power of the proposed test are reported. The simulation results indicate that exact test is extremely satisfactory for controlling type Ⅰ error probability.     

Reflection on the Purposes of Research,Action, and Scholarship: A Case of Cross-Cultural Participatory Action Research

Beginning with some basic principles of participatory action research, the author draws upon personal experience to identify the ways in which the experience of the practice of participatory action research creates forms of publication somewhat different in intent and nature from conventional forms of research. The experience selected involves cross-cultural research, and the particular problems of representation of the other in such settings are engaged. The overall experience is then drawn upon to identify some of the key qualities of action research which differ both from other forms of research and from some of the advocacies for action research.     

证据冲突:丢弃,发现或化解?

组合可能冲突的信息是智能推理中重要的研究内容,其中,证据理论是一种典型的不确定性智能推理方法。在证据理论中,用以融合和更新证据信息的推理组合规则是其理论基石。Dempster组合规则通过合取运算来构造信息结构,得到了广泛的应用。然而,当证据冲突比较大、证据源不完全可靠或辨识框架不完备时,Dempster组合规则得到的结果并不符合常理。为此,改进组合规则和处理证据冲突,成为证据理论中一个重要的研究课题。将全面回顾和比较国内外现有的主要推理组合方法,基于不同的冲突处理机制,建立相应的理论框架,涵盖绝大多数推理方法,从理论上对证据推理方法的研究,进行一个全面的总结,并剖析各种组合方法的优缺点和相互关系,指出最新的研究趋势。