Proceedings of the 12th EAI International Conference on Performance Evaluation Methodologies and Tools最新文献

{"title":"Markov regenerative processes solution and stochastic model checking: an on-the-fly approach","authors":"S. Donatelli","doi":"10.1145/3306309.3306310","DOIUrl":"https://doi.org/10.1145/3306309.3306310","url":null,"abstract":"Stochastic model checking is a technique to check if a Markov chain satisfies a path property. This typically requires the computation of the probability of the set of paths of the continuous Time Markov chain (CTMC) that satisfy a given set of requirements that are given in terms of visited states, events occurrence and time constraints at which the events occur. In particular we shall address the stochastic logic CSLTA [12], in which the properties to be satisfied are specified as one-clock timed automaton [1]. CSLTA is strictly more expressive than the well known stochastic logic CSL [8]. It has been proved in [12] that the computation of the set of states that satisfy a CSLTA property requires the solution, in steady-state, of a Markov Regenerative Process (MRgP) of a size that is of the order of the size of the CTMC multiplied by the size of the timed automata state space: space and time can be a severe impairment for the efficacy of stochastic model checking. In this talk we shall review advanced techniques for MRgP solution [4, 6, 7, 10, 13] and standard techniques for the state space construction of timed automata [9], to show how they can work in a synergic manner to devise a model checking algorithm for CSLTA that works on components (to save time), and that is able to build the components on-the-fly, only when needed (to save space), leading to the OTF technique, the main topic of this talk [2]. A comparison with the component-based technique in [15] for the CSLTA model-checking of infinite Markov chain will also be discussed. OTF (as well as other component-based model-checking algorithms) has been implemented both as an in-line tools called MC4CSLTA [5] and as a fully integrated component of the graphical interface of GreatSPN [3], a tool for the solution and the (stochastic) verification of (stochastic) Petri nets. We shall compare the time and space complexity of OTF with previous approaches based on components. Moreover we shall also compare the performances of OTF with those of two CSL model checkers: Prism [14] and Storm [11], clearly limited to CSL formulas.","PeriodicalId":113198,"journal":{"name":"Proceedings of the 12th EAI International Conference on Performance Evaluation Methodologies and Tools","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126281829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal Power Allocation in a Relay-aided Cognitive Network","authors":"Anne Savard, E. Belmega","doi":"10.1145/3306309.3306314","DOIUrl":"https://doi.org/10.1145/3306309.3306314","url":null,"abstract":"In this paper, we address a power allocation problem in a relay-aided cognitive network. The network is composed by a primary and secondary user/destination pair and a relay, which helps the communication between the secondary user and its destination. The transmission of the secondary user and the helping relay is allowed provided that a minimum quality of service (QoS) constraint is met at the primary user. First, we derive the achievable rate regions under Decode-and-Forward (DF) and Compress-and-Forward (CF) relaying schemes. Then, we provide analytic expressions of the optimal power allocation policies at the secondary user and the relay. Remarkably, if the secondary direct link is negligible - the communication takes place only via the relay - DF is proven to always outperform CF, irrespective from the system parameters. If the secondary direct link is not negligible, our numerical results illustrate that DF outperforms CF only when the relay is close to the secondary user.","PeriodicalId":113198,"journal":{"name":"Proceedings of the 12th EAI International Conference on Performance Evaluation Methodologies and Tools","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134124633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tandem stochastic systems: Jackson networks, asymmetric exclusion processes, asymmetric inclusion processes and Catalan numbers","authors":"U. Yechiali","doi":"10.1145/3306309.3306312","DOIUrl":"https://doi.org/10.1145/3306309.3306312","url":null,"abstract":"A tandem stochastic system is a network of n sites (queues) in series, where particles (customers, jobs, packets, etc.) move unidirectionally from one site to the next until they leave the system. When each site is an M/M/1 queue, i.e., where the buffer size of each site is unlimited and only single particles move between sites, the system is known as Tandem Jackson Network (TJN) [3]. The TJN is famous for its product-form solution of the multi-dimensional distribution function of the sites' queue-sizes (occupancies). Another well-known tandem stochastic system is the Asymmetric Simple Exclusion Process (ASEP) [1], where each site can hold at most a single particle, a constraint that causes blockings on particles' forward movements. The ASEP is a paradigmatic model in non-equilibrium statistical mechanics. In contrast, the newly introduced (Reuveni, Eliazar and Yechiali) Asymmetric Inclusion Process (ASIP) is a tandem series of sites, each with unbounded buffer capacity and with unlimited-size batch service [5]. That is, when service is completed at site k, all particles present there move simultaneously to site k + 1 and form a cluster together with the cluster of particles (if any) already residing in site k + 1. The ASIP is a showcase of complexity [6]. We analyze the innovative ASIP and show that its multi-dimensional Probability Generating Function (PGF) does not admit a product-form solution. Nevertheless, we present a method to calculate this PGF [5]. Surprisingly though, the load (total number of particles up to site k) does admit a product-form solution. It is consequently shown that homogeneous systems (i.e. systems with identical servers) are optimal for various load-related objective functions [5]. Considering the total number of particles in a site-interval of length m (m = 1, 2,..., n) that starts at site k, the corresponding probability generating functions create a discrete two-dimensional boundary-value problem which is solved explicitly [8]. Catalan's numbers, and their generalizations, arise naturally in this context [4]. It is further proved [8] that the probability of site k being positively occupied is proportional to 1/√k, while the variance in the occupancy of site k is proportional to √k. Finally, we derive limit laws (when the number of sites becomes large) for various system's variables [7]. In particular, we show that the 'load', as well as the 'draining time', each obeys a Gaussian distribution (with corresponding coefficients), while the 'inter-exit time' follows a Rayleigh distribution. An extension of the basic ASIP model with a fairly general arrival scheme, where gate opening intervals follow a Markov renewal process, is studied in [2]. The steady-state distribution of the total number of customers in the first k queues is determined.","PeriodicalId":113198,"journal":{"name":"Proceedings of the 12th EAI International Conference on Performance Evaluation Methodologies and Tools","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115554544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Uncle Traps: Harvesting Rewards in a Queue-based Ethereum Mining Pool","authors":"Sam M. Werner, Paul J. Pritz, Alexei Zamyatin, W. Knottenbelt","doi":"10.1145/3306309.3306328","DOIUrl":"https://doi.org/10.1145/3306309.3306328","url":null,"abstract":"Mining pools in Proof-of-Work cryptocurrencies allow miners to pool their computational resources as a means of reducing payout variance. In Ethereum, uncle blocks are valid Proof-of-Work solutions which do not become the head of the blockchain, yet yield rewards if later referenced by main chain blocks. Mining pool operators are faced with the non-trivial task of fairly distributing rewards for both block types among pool participants. Inspired by empirical observations, we formally reconstruct a Sybil attack exploiting the uncle block distribution policy in a queue-based mining pool. To ensure fairness of the queue-based payout scheme, we propose a mitigation. We examine the effectiveness of the attack strategy under the current and the proposed policy via a discrete-event simulation. Our findings show that the observed attack can indeed be obviated by altering the current reward scheme.","PeriodicalId":113198,"journal":{"name":"Proceedings of the 12th EAI International Conference on Performance Evaluation Methodologies and Tools","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128322619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Data-driven appointment scheduling","authors":"D. Fiems","doi":"10.1145/3306309.3306311","DOIUrl":"https://doi.org/10.1145/3306309.3306311","url":null,"abstract":"We consider the problem of evaluating and constructing appointment schedules for patients in a health-care facility where a single physician treats patients in consecutive order, as is common for general practitioners, clinics and for outpatients in hospitals. Specifically, given a fixed-length session during which a physician sees K patients, each patient has to be given an appointment time during this session in advance. Optimising a schedule with respect to patient waiting times, physician idle times, session overtime, etc. usually requires a heuristic search method involving a huge number of repeated schedule evaluations. Methods for lowering the computational cost of obtaining accurate predictions is the main thread of this talk. Borrowing from queueing theory, we first show that a Lindley-type recursion in a discrete-time framework can be used to obtain accurate predictions for the moments of the patient waiting times and the doctor's idle times and overtime in the simplest setting where patients are identical, punctual and always show up. Unfortunately, in realistic scenarios, patients are neither statistically identical (in many scenarios, the consultation times of particular patients can be estimated based on the lengths of prior consultations of the same patient or of patients with similar conditions) nor punctual and a considerable number of patients do not show up. Various extensions to evaluate schedules with unpunctuality and no-shows are discussed, both completely numerical methods as well as methods which combine numerical results and Monte-Carlo simulation. The evaluation methods are then used in combination with a local search algorithm to optimise the schedule. Finally, noting that it is often beneficial to be scheduled early during a session, we consider an appointment game in which patients can opt to be seen in a later session, as to reduce their waiting during the session. Both the unobservable and observable game are considered, i.e., the patients are either aware of the number of patients already scheduled in the future sessions, or they are not.","PeriodicalId":113198,"journal":{"name":"Proceedings of the 12th EAI International Conference on Performance Evaluation Methodologies and Tools","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123792876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the Performance of C and C++ Cryptographic Libraries","authors":"Majed Alrowaithy, N. Thomas","doi":"10.1145/3306309.3306335","DOIUrl":"https://doi.org/10.1145/3306309.3306335","url":null,"abstract":"This paper presents a study on performance comparison of several cryptographic primitives from six C/C++ open source libraries with the aim to understand the performance cost of the primitives and to find the most efficient primitive and library. The paper will also study the effect of the key length on the performance of variable key-length primitives. The results show that AES is the most efficient block cipher tested. The size of the key has some effect on the performance of the primitives. Smaller key sizes show better performance. However, this is not true for all the primitives with variable key length.","PeriodicalId":113198,"journal":{"name":"Proceedings of the 12th EAI International Conference on Performance Evaluation Methodologies and Tools","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133899738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A proof of the conjecture in \"Pricing surplus server capacity for mean waiting time sensitive customers\"","authors":"Manu K. Gupta, N. Hemachandra","doi":"10.1145/3306309.3306332","DOIUrl":"https://doi.org/10.1145/3306309.3306332","url":null,"abstract":"This paper settles the conjecture of Sinha, Rangaraj and Hemachandra (2010) [12], on a joint pricing and scheduling problem. The overall objective of this problem is to optimally price the server's surplus capacity by introducing price and mean waiting time sensitive new (secondary) class of customers that also satisfy the predefined service level requirement of the existing (primary) class of customers. The optimal pricing and scheduling parameters depend on the solution of two optimization problem and the conjecture is in the context of comparison of these two objective functions for a certain finite range of service level. Thus, the finite step algorithm (assuming conjecture is true) in Sinha, Rangaraj and Hemachandra (2010) [12] to obtain optimal pricing and operating parameters is valid. The above model can be used to capture strategic interaction between service-provider (as a queue) and user-set (customers).","PeriodicalId":113198,"journal":{"name":"Proceedings of the 12th EAI International Conference on Performance Evaluation Methodologies and Tools","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114911720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revenue-Driven Scheduling in Drone Delivery Networks with Time-sensitive Service Level Agreements","authors":"Shireen Seakhoa-King, P. Balaji, Nicolas Trama Alvarez, W. Knottenbelt","doi":"10.1145/3306309.3306339","DOIUrl":"https://doi.org/10.1145/3306309.3306339","url":null,"abstract":"Drones are widely anticipated to be used for commercial service deliveries, with potential to contribute to economic growth, estimated at £42 billion in the UK alone by the year 2030. Alongside air traffic control algorithms, drone-based courier services will have to make intelligent decisions about how to deploy their limited resources in order to increase profits. This paper presents a new scheduling algorithm for optimising the revenue of a drone courier service provider in these highly utilised time-sensitive service delivery systems. The first input to the algorithm is a monotonically decreasing value over time function which describes the service level agreement between the service provider and its customers. The second is the anticipated drone flight-time duration distribution. Our results show that the newly-developed scheduling algorithm, Least Lost Value, inspired by concepts for real-time computational workload processing, is able to successfully route drones to extract increased revenue to the service provider in comparison with two widely-used scheduling algorithms: First Come First Served and Shortest Job First, in terms of realised revenue.","PeriodicalId":113198,"journal":{"name":"Proceedings of the 12th EAI International Conference on Performance Evaluation Methodologies and Tools","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114261483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Uplink Contention-based Transmission Schemes for URLLC Services","authors":"M. Deghel, P. Brown, S. Elayoubi, Ana Galindo-Serrano","doi":"10.1145/3306309.3306323","DOIUrl":"https://doi.org/10.1145/3306309.3306323","url":null,"abstract":"We investigate in this paper uplink multiple transmission schemes for 5G Ultra-Reliable Low Latency Communications (URLLC) traffic. The URLLC class of services has been defined for applications requiring extremely stringent latency and reliability. We show that, in systems with episodic traffic and many users compared with the number of transmission resources, randomly transmitting multiple copies of a packet allows to meet the URLLC requirements. We develop analytical models for the packet loss rate for two contention based multiple transmission schemes and show that one dominates the other in the parameter range for which the URLLC requirements are met. We then show on a possible radio setting for 5G, an example of radio resource dimensioning for different user traffic levels and we illustrate how the latency constraint may limit the allowable traffic for a given radio bandwidth.","PeriodicalId":113198,"journal":{"name":"Proceedings of the 12th EAI International Conference on Performance Evaluation Methodologies and Tools","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134187076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A bottleneck with randomly distorted arrival times","authors":"D. V. Leeuwen, Sara Ghazanfari, L. Ravner, R. N. Queija","doi":"10.1145/3306309.3306319","DOIUrl":"https://doi.org/10.1145/3306309.3306319","url":null,"abstract":"We investigate the impact of random deviations in planned arrival times on user equilibrium in an extension of Vickrey's celebrated bottleneck model. The model is motivated by the fact that in real life, users can not exactly plan the time at which they depart from home, nor the delay they experience before they join the congestion bottleneck under investigation. We show that the arrival density advocated by the Nash equilibrium in Vickrey's model, is not a user equilibrium in the model with random uncertainty. We then investigate the existence of a user equilibrium for the latter and show that in general such an equilibrium can neither be a pure Nash equilibrium, nor a mixed equilibrium with a continuous density. Our results imply that when random distortions influence user decisions, the dynamics of standard bottleneck models are inadequate to describe such more complex situations. We illustrate with numerical analysis how the mechanics of a bottleneck with delayed arrivals are unstable for any continuous arrival strategy, thus shedding more light on the non-existence result.","PeriodicalId":113198,"journal":{"name":"Proceedings of the 12th EAI International Conference on Performance Evaluation Methodologies and Tools","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116265553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}