QoS-aware service evaluation and selection

Making the provision of services QoS-aware is to the advantage of both clients and providers in the e-business domain. This paper studies the problem of providers that receive multiple concurrent requests for services demonstrating different QoS properties. It introduces the “Selective Multiple Choice Knapsack Problem” that aims to identify the services, which should be delivered in order to maximise the provider’s profit, subject to maximum bandwidth constraints. This problem is solved by a proposed algorithm that has been empirically evaluated via numerous experiments.     

Reallocation of paths of ABR services in a multistage interconnection network (MIN)-type ATM switch network

In this paper, we develop algorithms for reallocating paths of available bit rate (ABR) services in an asynchronous transfer mode (ATM) switch network. ATM traffic control for fair share bandwidth allocation is usually performed under the assumption that paths of all services in a switch network are fixed. However, each connection may have multiple paths from an ingress queue to an egress queue since most ATM switch networks have the structure of the multistage interconnection network of switch elements. Therefore, paths already established for ABR connections may have to be changed to enhance throughput of the switch, if the ATM switch has the capability of adjusting paths of ABR connections while they are being served. We present three algorithms, in which throughput for ABR connections is estimated to decide whether or not paths of the connections should be changed. These algorithms are compared with an existing traffic management algorithm through simulation experiments. Results of the experiments show that the suggested algorithms give higher throughput in terms of the number of transmitted ABR cells without increasing the delay time of ABR services as well as quality of service (QoS) guaranteed services or decreasing the number of transmitted cells of QoS guaranteed services.     

Pricing surplus server capacity for mean waiting time sensitive customers

We consider a queueing model wherein the resource is shared by two different classes of customers, primary (existing) and secondary (new), under a service level based pricing contract. This contract between secondary class customers and resource manager specifies unit admission price and quality of service (QoS) offered. We assume that the secondary customers’ Poisson arrival rate depends linearly on unit price and service level offered while the server uses a delay dependent priority queue management scheme. We analyze the joint problem of optimal pricing and operation of the resource with the inclusion of secondary class customers, while continuing to offer a pre-specified QoS to primary class customers. Our analysis leads to an algorithm that finds, in closed form expressions, the optimal points of the resulting non-convex constrained optimization problem. We also study in detail the structure and the non-linear nature of these optimal pricing and operating decisions.     

Resource allocation for end-to-end QoS provisioning in a hybrid wireless WCDMA and wireline IP-based DiffServ network

In the future UMTS network, the heterogeneous traffics of multimedia services demand various QoS provisioning. At the same time, the seamlessly conveying of information between mobile users and a hybrid network requires the networking from wireless to wireline domains. However, in both academia and industries, the end-to-end QoS provisioning in the integration of wireline and wireless networks remains a challenge. In this paper, a modeling of a hybrid wireless WCDMA and wireline IP-based DiffServ network is presented to investigate the resource allocation for end-to-end QoS provisioning for multimedia services. In the wireless domain, the mathematical modeling of the cross-layer model including the physical layer, the link layer and the network layer is built. The connection admission control scheme is implemented based on the cross-layer model to determine the amount of resource for different services. In the wireline domain, we define the mapping of QoS classes between UMTS and DiffServ networks according to different QoS requirements. We propose a bandwidth allocation scheme to provide satisfactory packet loss and delay guarantee in DiffServ networks. The final end-to-end admission control scheme combines the resource allocation and admission control in both wireless and wireline domains. The analytical and simulation results show that the proposed resource allocation and admission control schemes work cooperatively in the presented hybrid wireless and wireline networks to guarantee the end-to-end QoS requirements for multimedia services.     

Load balancing optimization of telecommunication networks with two differentiated services

The Differentiated Services architecture is a scalable solution to provide differentiated Quality of Service. In this paper, we address the network load balancing optimization of such networks based on bandwidth differentiation between two services. We define the optimization problem as an Integer Programming model and propose a heuristic algorithm based on GRASP with Path Relinking. We present computational results showing that (i) good quality solutions can be computed and (ii) proper load balancing can efficiently obtain service differentiation.     

基于QoS协同关联的改进Skyline制造服务组合优化方法

服务社会网络环境下,云制造服务通过与其他参与同一任务的服务共享与竞争物理设备、信息、知识等资源形成协同效应,对双方实际执行效果具有重要影响,导致出现QoS偏离现象,现有服务选择模型难以适应这一情景。根据服务协同网络特点,本文提出基于QoS协同关联的制造服务组合方法。运用QoS协同关联和协同系数表达资源共享、冲突对QoS的影响程度,构建了新的服务选择优化模型。基于创新Skyline服务对概念,改善了Skyline算法在QoS协同关联条件下的搜索效率和结果,通过智能汽车制造仿真实验,验证了本文模型和算法的有效性。     

A capacitated firm’s pricing strategies for strategic consumers with different search costs

This paper studies pricing strategies of a seller with budget constraints facing two types of strategic consumers with different search costs, and proposes three pricing strategies to motivate all consumers to visit his shop. These are the basic price strategy, differentiated compensation strategy and an improved differentiated compensation strategy. Based on the rational expectations paradigm, we characterize the rational expectations equilibrium in the game and propose a basic pricing strategy. In order to address the interplay between price and demand, we further propose a differentiated compensation strategy to improve the basic model. We then compare the differentiated compensation strategy to the basic pricing strategy when both are feasible. We find that selection of the optimal strategy is independent of composition of consumers but is dependent on the seller’s budget level and the difference between the two search costs. If the budget is large enough and the difference between the search costs is small enough, a differentiated compensation strategy can further improve the seller’s profitability. In addition to these findings, we first propose an improved differentiated compensation strategy to further enhance the firm’s profit. We find that the optimal strategy is to implement the improved differentiated compensation strategy when all three strategies are feasible. Interestingly, the firm may benefit from paying a high compensation to the consumers.     

具有违约风险的人寿保险的最优定价

本文探讨具有违约风险的人寿保险的最优定价.我们从Black-Scholes的期权定价模型出发,考虑风险管理和准备金的要求,根据一次支付和均衡支付这两种不同的假设分别建立两个优化模型,并且借助于优化技术获得最优解.数量化分析结果表明,两个模型的最优价格对于利息率参数以及非索赔成本的变化都不敏感.这说明这两个模型是稳定的,而且是实用的.     

政府奖励与惩罚机制下闭环供应链网络均衡的互补模型

为研究政府经济政策对闭环供应链的影响,以非线性互补理论为基本工具,分别得到了在政府奖励机制与惩罚机制下,制造商负责回收的闭环供应链网络的各层均衡及整体均衡条件、经济解释及对应的非线性互补模型.最后通过数值算例验证了模型的正确性与有效性,其分析结果表明当政府预期的最低回收率较低时,惩罚机制优于奖励机制;当政府预期的最低回收率较高时,奖励机制优于惩罚机制.政府部门为了达到预期的最低回收率目标,可以适当调整奖励因子与惩罚因子.     

Fair resource allocation for different scenarios of demands

This paper considers a resource allocation problem, which objective is to treat fairly all the system users. Usually the requests cannot be entirely predicted, but the manager can forecast the request evolution, this leading to a set of possible scenarios. Such a problem arises for instance in network bandwidth allocation as well as in storage space management. It also appears in the management of computer systems, such as computational grids or in cloud computing, when teams share a common pool of machines. Problems of fair resource sharing arise among users with equal access right but with different needs.Here the problem is tackled by a multi-criteria model, where one criterion is associated to one scenario. A solution is a policy, which provides an allocation for each scenario. An algorithm is proposed and analysed that lists all solutions which are Pareto optimal with regard to the different possible user request scenarios. The algorithm is used offline, but can be adapted, with some additional hypothesis, to be used online.     

Modeling Optimal Effective Bandwidth of Page-Mode Memory for Stream-Oriented Computations

Memory system performance models have traditionally assumed that individual modules are insensitive to the sequence cf access requests. For current memory components, this assumption is not correct. Furthermore, performance models generally assume a stochastic sequence of reference. For stream-oriented computations, such models of reference are not suitable. This paper derives the optimal effective memory bandwidth achieved by stream-oriented computations at a single module of such memory components.     

A Calculus for Generic, QoS-Aware Component Composition

Software QoS properties, such as response time, availability, bandwidth requirement, memory usage, among many others, play a major role in the processes of selecting and composing software components. This paper extends a component calculus to deal, in an effective way, with them. The calculus models components as generalised Mealy machines, i.e., state-based entities interacting along their life time through well defined interfaces of observers and actions. QoS is introduced through an algebraic structure specifying the relevant QoS domain and how its values are composed under different disciplines. A major effect of introducing QoS-awareness is that a number of equivalences holding in the plain calculus become refinement laws. The paper also introduces a prototyper for the calculus developed as a ‘proof-of-concept’ implementation.     

Planning and approximation models for delivery route based services with price-sensitive demands

Classical vehicle routing problems typically do not consider the impact of delivery price on the demand for delivery services. Existing models seek the minimum sum of tour lengths in order to serve the demands of a given set of customers. This paper proposes approximation models to estimate the impacts of price on delivery services when demand for delivery service is price dependent. Such models can serve as useful tools in the planning phase for delivery service providers and can assist in understanding the economics of delivery services. These models seek to maximize profit from delivery service, where price determines demand for deliveries as well as the total revenue generated by satisfying demand. We consider a variant of the model in which each customer’s delivery volume is price sensitive, as well as the case in which customer delivery volumes are fixed, but the total number of customers who select the delivery service provider is price sensitive. A third model variant allows the delivery service provider to select a subset of delivery requests at the offered price in order to maximize profit.     

Simulation and Analysis of a New Mobility Model for Mobile Communication Networks

The traffic generation models, which describe how the clients use the network services, as well as the mobility models, which describe how clients move within the service area covered by the network, are essential tools for QoS analysis in these environments. In this paper we present the simulation of a new mobility model implemented for the analysis of QoS parameters of a mobile network, such as channel occupation time, handoff and new call blocking probabilities.     

A note on risk premiums with random initial wealth

This paper examines the risk premium for removing one risk when other risks are present. We use both mean-variance and stochastic dominance models to examine when such a risk premium might be negative.     

Solving the Two-Stage Robust FTTH network design Problem under Demand Uncertainty

For the past few years, the increase in high bandwidth requiring services forced telecommunication operators like France Telecom - Orange to engage the deployment of optical networks, the Fiber To The Home Gigabit Passive Optical Network (FTTH GPON) technology, leading to new design problems. Such problems have already been studied. However, to the best of our knowledge, without taking into account the future demand uncertainty. In this paper, we propose a model for a two-stage robust optimization FTTH network design problem tackling the demand uncertainty. We propose an exact algorithm, based on column and constraint generation algorithms, and we show some preliminary results.     

Banking behaviour after the lifecycle event of “moving in together”: An exploratory study of the role of marketing investments

This study addresses an important issue for both managers and researchers: whether it is advantageous for financial services providers to invest in youth marketing. More specifically, the effectiveness of these investments is evaluated in terms of retention proneness once youngsters enter the lifecycle event of “moving in together”. The study identifies eight constructs of youth marketing and contrasts their impact against the best deal when youngsters decide to move in together and consequently experience the need to buy their first collectivized financial products, such as a joint account or a mortgage for their new home. Furthermore, the influence of the partner, prior patronage behaviour, customer demographics and psychographic variables are tested for. The findings of the study reveal that: (i) individuals are likely to change their banking behaviour during crucial lifetime events such as moving in together, (ii) not all youth marketing investments are equally effective, while (iii) the best deal components (e.g. convenience, price conditions, etc.) have a major impact.     

Fuzzy pricing,marketing and service planning in a fuzzy inventory model: A geometric programming approach

In the real world markets, demand is influenced by different parameters. Recently, many researchers have been interested in integrated production and marketing planning strategies in inventory models where demand depends on different parameters such as price and/or marketing expenditure. The quality of services that are offered to customers of a product is one of the most important parameters that affects demand in the real markets and has not been considered in development of inventory models. On the other hand, the cost parameters in real inventory systems and other parameters such as price, marketing and service elasticity to demand are imprecise and uncertain in nature. So, the notion of fuzziness can be applied to cope with this uncertainty. In this paper, a new fuzzy profit maximization inventory model with shortages is proposed. The demand is considered as a power function of price, marketing expenditure and service expenditure. Furthermore, unit cost is determined as a power function of order quantity. Since the proposed model is in a fuzzy environment, a fuzzy decision should be made to meet the decision criteria, and the results should be fuzzy. Therefore, the proposed model is formulated and solved using geometric programming and fuzzy optimization techniques to derive an approximation of the results’ membership functions. The model is illustrated with a numerical example and finally a case study is provided for evaluation and validation of the results of model.     

Single courier single restaurant meal delivery (without routing)

We investigate optimization models for meal delivery that do not involve routing. We focus on the simplest case, with a single restaurant and a single courier, and reduce it to the throughput maximization single machine scheduling problem, with release times and bounded slacks. In the meal delivery setting, slacks are small for QoS purposes and we indeed show that the scheduling problem can be solved in polynomial time when slacks are bounded. We discuss extensions to more couriers and restaurants.