Service Discipline Research Articles

A Bitcoin-inspired infinite-server model with a random fluid limit

The synchronization process inherent to the Bitcoin network gives rise to an infinite-server model with the unusual feature that customers interact. Among the closed-form characteristics that we derive for this model is the busy period distribution which, counterintuitively, does not depend on the arrival rate. We explain this by exploiting the equivalence between two specific service disciplines, which is also used to derive the model’s stationary distribution. Next to these closed-form results, the second major contribution concerns an asymptotic result: a fluid limit in the presence of service delays. Since fluid limits arise under scalings of the law-of-large-numbers type, they are usually deterministic, but in the setting of the model discussed in this paper the fluid limit is random (more specifically, of growth-collapse type).

Stability Conditions for Queueing Systems with Regenerative Flow of Interruptions

This paper is focused on the multichannel queueing system with heterogeneous servers, regenerative input flow, and a regenerative process of interruptions. Two service disciplines are studied: pree...

Optimum Transmission Window for EPONs With Limited Service

This paper studies the Ethernet passive optical network (EPON) with limited service. The transmission window (TW) is limited in this system to guarantee a bounded delay experienced by disciplined users and to constrain malicious users from monopolizing the transmission channel. Thus, selecting an appropriate TW size is critical to the performance of EPON with limited service discipline. In this paper, we develop an M/G/1 queuing model with vacation times and limited-service discipline to investigate the impact of TW size on packet delay. A distinguishing feature of this model is that there are two queues in the buffer of each optical network unit (ONU): one queue is inside the gate and the other one is outside the gate, from which we derive the generalized formula of mean waiting time. Furthermore, based on the service-level agreements of users and the Chernoff bound of queue length, we provide a simple rule to determine an optimum TW size for limited-service EPONs. The analytic results reported in this paper are all verified by simulations.

Performance Analysis of a Polling Model With BMAP and Across-Queue State-Dependent Service Discipline

As various video services become popular, video streaming will dominate the mobile data traffic. The H.264 standard has been widely used for video compression. As the successor to H.264, H.265 can compress video streaming better, hence it is gradually gaining market share. However, in the short term H.264 will not be completely replaced, and will co-exist with H.265. Using H.264 and H.265 standards, three types of frames are generated, and among different types of frames exist dependencies. Since the radio resources are limited, using dependencies and quantities of frames in buffers, an appropriate time division transmission policy can be applied to transmit different types of frames sequentially, in order to avoid the occurrence of video carton or decoding failure. Polling models with batch Markovian arrival process (BMAP) and across-queue state-dependent service discipline are considered to be effective means in the design and optimization of appropriate time division transmission policies. However, the BMAP and across-queue state-dependent service discipline of the polling models lead to the large state space and several coupled state transition processes, which complicate the performance analysis. There have been very few researches in this regard. In this paper, a polling model of this type is analyzed. By constructing a supplementary embedded Markov chain and applying the matrix-analytic method based on the semi-regenerative process, the expressions of important performance measures including the joint queue length distribution, the customer blocking probability and the customer mean waiting time are obtained. The analysis will provide inspiration for analyzing the polling models with BMAP and across-queue state-dependent service discipline, to guide the design and optimization of time division transmission policies for transmitting the video compressed by H.264 and H.265.

PENGARUH KEDISIPLINAN MENJALANKAN SOP ALUR DINAS TERHADAP KINERJA MASINIS UPT CREW KA KERTAPATI PT KERETA API INDONESIA (PERSERO) DIVISI REGIONAL III PALEMBANG

This research is aimed to know the influence of discipline in running the SOP of the departmental flow to Performance Engineering UPT Crew KA Kertapati PT. Kereta Api Indonesia (Persero) Divre III Palembang. In this case the sample withdrawal using Boring Sampling method with the population of UPT Crew KA Kertapati as many as 78 people. From the results of the questionnaire, processed using SPSS for Windows version 20 by using simple linear regression method, uju hypothesis (t test), and correlation coefficient. Based on the analysis results obtained value coefficient (R) of 0.433 indicates that there is a strong relationship between the two variables. While on hypothesis (t test) get t value equal to 4,185 t table value sebesat 1,992, and significance value 0,000, then t arithmetic > t table and significance value <0,05, which means Ho rejected H1 accepted, that there is influence of Discipline In Running SOP Flow of Service to Performance. Can also be seen from the value of regression coefficient (R2) of 0.187 that the percentage contribution of variable Discipline In Running SOP Flow Service to variable Performance of 18.7% or variations of variables Discipline In Running SOP Flow Office used to explain the amount of 18.7% Performance variables. While the remaining 81.3% (100% -18.7%) influenced by other variables.

Priority queueing analysis of transaction-confirmation time for Bitcoin

In Bitcoin system, a transaction is given a priority value according to its attributes such as the remittance amount and fee, and transactions with high priorities are likely to be confirmed faster than those with low priorities. In this paper, we analyze the transaction-confirmation time for Bitcoin system. We model the transaction-confirmation process as a queueing system with batch service, M/ \begin{document}$ \mbox{G}^B $\end{document} /1. We consider the joint distribution of numbers of transactions in system and the elapsed service time, deriving the mean transaction-confirmation time. Using the result, we derive the recursive formulae of mean transaction-confirmation times of an M/ \begin{document}$ \mbox{G}^B $\end{document} /1 queue with priority service discipline. In numerical examples, we show the effect of the maximum block size on the mean transaction-confirmation time, investigating the accuracy region of our queueing model. We also discuss how the increase in micropayments, which are likely to be given low priorities, affects the transaction-confirmation time.

The (functional) law of the iterated logarithm of the sojourn time for a multiclass queue

Two types of the law of iterated logarithm (LIL) and one functional LIL (FLIL) are established for the sojourn time process for a multiclass queueing model, having a priority service discipline, one server and $K$ customer classes, with each class characterized by a batch renewal arrival process and independent and identically distributed (i.i.d.) service times. The LIL and FLIL limits quantify the magnitude of asymptotic stochastic fluctuations of the sojourn time process compensated by its deterministic fluid limits in two forms: the numerical and functional. The LIL and FLIL limits are established in three cases: underloaded, critically loaded and overloaded, defined by the traffic intensity. We prove the results by a approach based on strong approximation, which approximates discrete performance processes with reflected Brownian motions. We conduct numerical examples to provide insights on these LIL results.

Efficient computational analysis of non-exhaustive service vacation queues: BMAP/R/1/N(∞) under gated-limited discipline

• A finite-buffer vacation queue with batch Markovian arrival process has been analyzed. • The server is subjected to serve under gated-limited service discipline. • Proposed analysis is based on the successive substitution and the supplementary variable method. • The results have been matched with the corresponding infinite-buffer queue. • Numerical results are presented for different service- and vacation-time distributions. This paper analyzes the finite-buffer single server queue with vacation(s). It is assumed that the arrivals follow a batch Markovian arrival process ( BMAP ) and the server serves customers according to a non-exhaustive type gated-limited service discipline. It has been also considered that the service and vacation distributions possess rational Laplace-Stieltjes transformation (LST) as these types of distributions may approximate many other distributions appeared in queueing literature. Among several batch acceptance/rejection strategies, the partial batch acceptance strategy is discussed in this paper. The service limit L (1 ≤ L ≤ N ) is considered to be fixed, where N is the buffer-capacity excluding the one in service. It is assumed that in each busy period the server continues to serve until either L customers out of those that were waiting at the start of the busy period are served or the queue empties, whichever occurs first. The queue-length distribution at vacation termination/service completion epochs is determined by solving a set of linear simultaneous equations . The successive substitution method is used in the steady-state equations embedded at vacation termination/service completion epochs. The distribution of the queue-length at an arbitrary epoch has been obtained using the supplementary variable technique. The queue-length distributions at pre-arrival and post-departure epoch are also obtained. The results of the corresponding infinite-buffer queueing model have been analyzed briefly and matched with the previous model. Net profit function per unit of time is derived and an optimal service limit and buffer-capacity are obtained from a maximal expected profit. Some numerical results are presented in tabular and graphical forms.

Can automated content analysis be used to assess and improve the use of evidence in mental health policy? A systematic review

BackgroundThis review assesses the utility of applying an automated content analysis method to the field of mental health policy development. We considered the possibility of using the Wordscores algorithm to assess research and policy texts in ways that facilitate the uptake of research into mental health policy.MethodsThe PRISMA framework and the McMaster appraisal tools were used to systematically review and report on the strengths and limitations of the Wordscores algorithm. Nine electronic databases were searched for peer-reviewed journal articles published between 2003 and 2016. Inclusion criteria were (1) articles had to be published in public health, political science, social science or health services disciplines; (2) articles had to be research articles or opinion pieces that used Wordscores; and (3) articles had to discuss both strengths and limitations of using Wordscores for content analysis.ResultsThe literature search returned 118 results. Twelve articles met the inclusion criteria. These articles explored a range of policy questions and appraised different aspects of the Wordscores method.DiscussionFollowing synthesis of the material, we identified the following as potential strengths of Wordscores: (1) the Wordscores algorithm can be used at all stages of policy development; (2) it is valid and reliable; (3) it can be used to determine the alignment of health policy drafts with research evidence; (4) it enables existing policies to be revised in the light of research; and (5) it can determine whether changes in policy over time were supported by the evidence. Potential limitations identified were (1) decreased accuracy with short documents, (2) words constitute the unit of analysis and (3) expertise is needed to choose ‘reference texts’.ConclusionsAutomated content analysis may be useful in assessing and improving the use of evidence in mental health policies. Wordscores is an automated content analysis option for comparing policy and research texts that could be used by both researchers and policymakers.

The mean-field behavior of processor sharing systems with general job lengths under the SQ([formula omitted]) policy

This paper addresses the mean-field behavior of large-scale systems of parallel servers with a processor sharing service discipline when arrivals are Poisson and jobs have general service time distributions when an SQ(d) routing policy is used. Under this policy, an arrival is routed to the server with the least number of progressing jobs among d randomly chosen servers. The limit of the empirical distribution is then used to study the statistical properties of the system. In particular, this shows that in the limit as N grows, individual servers are statistically independent of others (propagation of chaos) and more importantly, the equilibrium point of the mean-field is insensitive to the job length distributions that has important engineering relevance for the robustness of such routing policies used in web server farms. We use a framework of measure-valued processes and martingale techniques to obtain our results. We also provide numerical results to support our analysis.

The National Information Exchange Model and making data relevant

The National Information Exchange Model (NIEM) has been widely adopted as a basis for creating standards that foster information exchanges across disparate disciplines in justice, health, human services and other fields. NIEM can be a driver for transforming legacy data into meaningful cross-disciplinary exchanges that can support advanced analysis of impacts of programs and strategies in improving government services of all categories. This presentation will review the basic NIEM principles in terms of how they can enable more meaningful results as administrative data is applied to research on the efficacy of government services across organizations and disciplines.

Limit Theorems for Queueing Systems with Various Service Disciplines in Heavy-Traffic Conditions

In this paper a multi-server queueing system with regenerative input flow and independent service times with finite means is studied. We consider queueing systems with various disciplines of the service performance: systems with a common queue and systems with individual queues in front of the servers. In the second case an arrived customer chooses one of the servers in accordance with a certain rule and stays in the chosen queue up to the moment of its departure from the system. We define some classes of disciplines and analyze the asymptotical behavior of a multi-server queueing system in a heavy-traffic situation (traffic rate ρ ≥ 1). The main result of this work is limit theorems concerning the weak convergence of scaled processes of waiting time and queue length to the process of the Brownian motion for the case ρ > 1 and its absolute value for the case ρ = 1.

KEWENANGAN PERADILAN MENGADILI TERHADAP SENGKETA AKTA PEJABAT PEMBUAT AKTA TANAH DAN BALIK NAMA PADA SERTIPIKAT BERDASARKAN HIBAH HAK ATAS TANAH YANG CACAT HUKUM

Abstract : The Background of the writing is the result of Palembang District Court No.62/PDT.G/2010/PN PLG juncto High Court verdict Palembang 101/PDT/2011/PT.PLG Number, Object lawsuit is Grant Deed No. 623/2009 dated July 30, 2009 which made before a Land Deed Official TA, SH. The decision of the judges in a lawsuit in state court can not be accepted and the decision of the judge also rejected the appeal in its entirety , a lawsuit can not be accepted because of the competence of courts to sue the Land Deed Officer and Head of the Land Office should at the State Administrative Court is not in Judicial Affairs , while the Grant Deed to cancel Judicial Affairs is the authority for Deed Land Deed Official beschikking not the result of a decision , but based on the wishes of the parties ( Partij acte ) contractual and to cancel the certificate that has been turned over the name of the authority of the State Administrative Court . Legal sanctions for Land Deed Official TA , SH which has made the Deed of Grant No. 623/2009 dated July 30, 2009 which can be legally flawed administrative sanctions and dismissal with no respect from his post by the National Land Agency of the Republic of Indonesia , after a court ruling have permanent legal force . While the legal sanctions for the Head of the Land Office had registered under the name of the Certificate of Property No. 910/24 downstream Village by the Deed of Grant No. 623/2009 which is a legal disability for severe disciplinary offense which is the Head of the Land Office for Civil Servants, the sanction under Article 7 figure 4 Government Regulation No. 53 of 2010 Concerning Civil Service Discipline, demotion level may be lower for 3 (three) years, in order to decrease the transfer of lower level positions, exemption from office, dismissal with respect not by his own request as Employee Civil, and dismissal with no respect as a civil servant. Keywords : the Judicial Authority of judging, registration of transfer of rights of Evidence, Sanctions Law Land Deed Officer and Head of the Land Office

Optimising key performance indicator adherence with application to emergency department congestion

Many operational queueing systems must adhere to systems of Key Performance Indicators (KPIs), each comprising a waiting time limit and a level of compliance specifying the minimal fraction of customers that must meet the standard. KPIs are frequently employed as measures of system performance in health care settings. The primary flaw with KPIs is that they represent a system of constraints with no objective function. KPIs say nothing about customers who exceed their limit, so long as such occurrences are sufficiently rare, when in fact customers who miss their time limit in a health care setting are of greater importance, not lesser. We address this flaw by minimising the mean number of customers present who have exceeded their respective limits; we consider also weighted averages of the numbers in excess for each class. We then show that one logical service discipline to achieve this goal is the Accumulating Priority Queueing (APQ) discipline. We carry out numerical examples to investigate the utility of our method. We then apply the optimisation approach to the case of an Emergency Department in Southern Ontario, Canada.

Designing a Community Garden

Politecnico di Milano Coltivando is a convivial garden where people meet, experiment, cultivate crops and share their skills and ideas. Coltivando uses innovative service and spatial design knowledge and community consultation processes. Coltivando is a design research project that is documented throughout its entire process. It is also a social as well as an educational experiment. People from the same neighbourhood yet strangers to one another and design students from the different disciplines of service and spatial design are brought together.This paper is a project review that analyses and explains the context, the main outputs and innovation, the process, the obstacles, the impact, the users’ needs, the transferability of the solution and its dissemination.

Teacher Performance Assesment Application using Naive Bayes Classifier Method

In this study to determine the classification of teacher performance feasibility is by using naive bayes Classifier method. The input data comes from teacher data SMPN 1 Jabon Sidoarjo. The teacher data sample will be used as training data and data testing. The Naive Bayes classifier is a simple probability classifier that applies Bayes’s theorem.In this study, the feasibility assessment of teacher performance there are 8 criteria there are Service Orientation, Integrity, Commitment, Discipline, Cooperation, Teaching, Certification and Diploma. The output classification is the feasibility of teacher performance. The system is developed using under the programming language PHP and MySQL. Data used is 46 data which divided in two data that is training data as much 36 data and 10 data as test data. Tests on sample data with real data indicate the suitability of 90%.

Designing retail spaces for inclusion

This article delineates the existence of consumer groups with vulnerabilities, discusses the lack of attention paid to the topic of vulnerable consumers, and calls for both retailing academics and practitioners to work toward constructing frameworks for research and service provision that enhance the welfare of vulnerable consumers. Extant theories and frameworks comprising the foundational knowledge of the retailing and consumer service disciplines have largely explained the marketplace experiences of consumers, without investigating the needs of vulnerable consumer segments. Because the larger consumer base does not necessarily generalize to vulnerable consumers, little is known about how these specific groups of vulnerable consumers can realize the full value inherent in retail exchanges.

On the Power-of-d-choices with Least Loaded Server Selection

Motivated by distributed schedulers that combine the power-of-d-choices with late binding and systems that use replication with cancellation-on-start, we study the performance of the LL(d) policy which assigns a job to a server that currently has the least workload among d randomly selected servers in large-scale homogeneous clusters. We consider general job size distributions and propose a partial integro-differential equation to describe the evolution of the system. This equation relies on the earlier proven ansatz for LL(d) which asserts that the workload distribution of any finite set of queues becomes independent of one another as the number of servers tends to infinity. Based on this equation we propose a fixed point iteration for the limiting workload distribution and study its convergence. For exponential job sizes we present a simple closed form expression for the limiting workload distribution that is valid for any work-conserving service discipline as well as for the limiting response time distribution in case of first-come-first-served scheduling. We further show that for phase-type distributed job sizes the limiting workload and response time distribution can be expressed via the unique solution of a simple set of ordinary differential equations. Numerical and analytical results that compare response time of the classic power-of-d-choices algorithm and the LL(d) policy are also presented and the accuracy of the limiting response time distribution for finite systems is illustrated using simulations.

On a 2-class polling model with reneging and $$k_i$$ k i -limited service

This paper analyzes a 2-class, single-server polling model operating under a $$k_i$$ -limited service discipline with class-dependent switchover times. Arrivals to each class are assumed to follow a Poisson process with phase-type distributed service times. Within each queue, customers are impatient and renege (i.e., abandon the queue) if the time before entry into service exceeds an exponentially distributed patience time. We model the queueing system as a level-dependent quasi-birth-and-death process, and the steady-state joint queue length distribution as well as the per-class waiting time distributions are computed via the use of matrix analytic techniques. The impacts of reneging and choice of service time distribution are investigated through a series of numerical experiments, with a particular focus on the determination of $$(k_1,k_2)$$ which minimizes a cost function involving the expected time a customer spends waiting in the queue and an additional penalty cost should reneging take place.

A resource‐tuned QoS multicast routing protocol

SummaryThis paper presents a novel framework for quality‐of‐service (QoS) multicast routing with resource allocation that represents QoS parameters, jitter delay, and reliability, as functions of adjustable network resources, bandwidth, and buffer, rather than static metrics. The particular functional form of QoS parameters depends on rate‐based service disciplines used in the routers. This allows intelligent tuning of QoS parameters as functions of allocated resources during the multicast tree search process, rather than decoupling the tree search from resource allocation. The proposed framework minimizes the network resource utilization while keeping jitter delay, reliability, and bandwidth bounded. This definition makes the proposed QoS multicast routing with resource allocation problem more general than the classical minimum Steiner tree problem. As an application of our general framework, we formulate the QoS multicast routing with resource allocation problem for a network consisting of generalized processor sharing nodes as a mixed‐integer quadratic program and find the optimal multicast tree with allocated resources to satisfy the QoS constraints. We then present a polynomial‐time greedy heuristic for the QoS multicast routing with resource allocation problem and compare its performance with the optimal solution of the mixed‐integer quadratic program. The simulation results reveal that the proposed heuristic finds near‐optimal QoS multicast trees along with important insights into the interdependency of QoS parameters and resources.