Queues with hyper-poisson arrivals and bulk exponential service

Summary In this paper the time-dependent solution of a queueing system is discussed under the conditions (i) the units arrive according to Hyper-Poisson distribution withl branches (ii) the queue-discipline is ‘first come first served’ (iii) the Service-time distribution is exponential with maximum capacity ofM units being served at one instant. Some results have been obtained when the waiting space is finite; in particular the probability for service to be idle has been obtained. Also for infinite queueing-space case, the expressions for the state probabilities and the mean queuelength under steady state conditions have been found.     

Time dependent solution of a queueing problem with correlated batch arrivals and general service time distribution

This paper considers the transient behaviour of queueing problem in which (i) the arrivals occur in batches of variable size (ii) the arrival and no arrival of a batch at two consecutive transition marks are correlated (iii) the service time distribution for each, unit is general with probability density functionD(x). TheLaplace transform of various probability generating functions of queue length are obtained and some particular cases are derived therefrom.     

Queues with batch poisson arrivals and hyper-exponential service time distribution

Summary We consider in this paper the transient behaviour of the queuing system in which (i) the input, following a Poisson distribution, is in batches of variable numbers; (ii) queue discipline is ‘first come first served’, it being assumed that the batches are pre-ordered for service purposes; and (iii) service time distribution is hyper-exponential withn branches. The Laplace transform of the system size distribution is determined by applying the method of generating functions, introduced in queuing theory byBailey [1]. However, assuming steady state conditions to obtain, the problem is completely solved and it is shown that by suitably defining the traffic intensity factor,ϱ, the value,p ₀, of the probability of no delay, remains the same in this case of batch arrivals also as in the case of single arrivals. The Laplace transform of the waiting time distribution is also calculated in steady state case from which the mean waiting time may be calculated. Some of the known results are derived as particular cases.     

A queueing problem with correlated arrivals and correlated phase-type service zur theorie des rangtests

Summary This paper studies the steady-state behaviour of a discrete-time, single-channel, first-come-first-served queueing problem wherein (i) the arrivals at two consecutive time-marks are correlated (ii) the service is accomplished in phases and (iii) the completion of phases at two consecutive time-marks are correlated. The probability generating function (p.g.f.) of the number of phases waiting and in service is obtained. Further, the p.g.f. of queue length is obtained for the case when each unit demands only one phase of service, and the mean queue length is derived therefrom. Finally, the p.g.f. and the mean queue length are discussed for the special cases, (i) r=0,R≠0, (ii) r≠0,R=0, (iii) r=0,R=0, (iv) r≠0,R=−I, (v) r=0,R=−I, (vi) r=−I,R≠0, (vii) r=−I,R=0, (viii) r=I,R≠0, (ix) r=I,R=0, (x) r≠0,R=I, (xi) r=0,R=I, where r andR are the respective coefficients of correlation between arrivals and completion of phases at two consecutive time-marks.     

Commuter arrivals and optimal service in mass transit: Does queuing behavior at transit stops matter?

This paper considers whether the optimal (second-best) mass-transit policy under a uniform-fare constraint is affected by passengers' queuing disciplines, by comparing the first-in-first-out (FIFO) and the random-access queuing. We analyze the problem by extending the model of mass-transit in Kraus and Yoshida (JUE(2002)) to the case of random-access queuing. The model involves the optimal number and capacity of trains as well as pricing. It is shown that, when the shadow value of a unit of waiting time exceeds that of a unit time of being late, the passengers' queuing discipline does not have any effect on the optimal (second-best) mass-transit policy including the number of trains and runs, scheduling, and pricing. If in turn, the shadow value of a unit of waiting time is smaller than that of being late, then aggregate travel costs are lower with random-access queuing than with FIFO, due to randomization of passengers' positions in a mass.     

Foreign arrivals nowcasting in Italy with Google Trends data

Quality & Quantity - The development of the ICT has deeply transformed the tourism industry. ICT has become a key determinant for competitiveness that deeply impacts on marketing and...     

Controls,service type and perceived supplier performance in interfirm service exchanges

Control offers a critical differentiator between successful and failed interfirm service exchanges. The application of informal control to improve supplier performance has been well established, but the effect of formal control appears profoundly equivocal. This study proposes that the actual effect of formal control depends on its mode (output vs. behavior) and its relationship with the service type (mass vs. professional) and informal control. With survey data from 252 service buying organizations, the results indicate that output control interacts with service type to determine perceived supplier performance (PSP). Buyers’ reliance on high output control has a positive effect on PSP in mass service exchanges; this effect becomes negative in professional service exchanges. The effect of the interaction of behavior control and service type also depends on the presence of informal control. Buyers’ reliance on high behavior control exerts a more positive effect on PSP in professional service exchanges than in mass service exchanges, but only in the presence of informal control. These findings have key implications for both theory and practice.     

A queueing problem with batch arrivals and correlated departures

Summary This paper considers the steady state behaviour of a queueing system in which (i) the input following the Hypergeometric Distribution is in batches of variable size (ii) queue discipline is first come first served it being assumed that the batches are preordered for service purposes and (ii) the service at two consecutive time marks is correlated. Probability generating functions for the various cases have been obtained and the mean queue lengths derived.     

On the relationship between cost and service models for general inventory systems

In this paper, we present a systematic overview of possible relations between cost and service models for fairly general single- and multi-stage inventory systems. In particular, we relate various types of penalty costs in pure cost models to equivalent types of service measures in service models. We show how an optimal policy for a service model may be obtained from cost-optimal policies in a related pure cost model. Pure cost models have been studied extensively in the literature. By our results it seems possible to transform many of the known optimal solutions for pure cost models to service models, which are more appropriate from a practical point of view. A number of examples are discussed to show the generality and the possibly far reaching consequences of the results.     

On Bayesian optimum allocation in some two phase sampling problems

Summary For estimating certain parametric functions, we consider the problem of allocatingN _i, the size of the sample from theith population,i=1,2,...,k, at the second phase of sampling of a two phase sampling procedure, given that we taken _i observations from the population at the first phase. We consider that the observations from theith population follow the exponential distribution with mean _i,i=1,2,...,k, and the functions to be estimated are (i) (d_i/_i) and (ii) (d_ii). When the total cost of sampling at the second phase is c _iN_i and is fixed, allocations using the Bayes approach are obtained so that the estimation is as precise as is possible.     

On the queueing problem of correlated arrivals with many servers in a finite waiting space

This paper provides an analysis of the steady state behaviour of a discrete time, first come first served limited space queueing problem with many serers. The arrival probabilities at two consecutive time-marks are correlated, whereas the departure probabilities, though depending on the queue length, are assumed to be statistically independent. Probability generating functions for the queue length for the various cases have also been listed. A few particular cases have also been derived. Mean queue lengths are also found out.     

Asymptotic properties of a correlation coefficient type statistic connected with the general linear model

It is proved that under certain conditions the conditional distribution of the sample multiple correlation coefficient given the ‘other’ observations in a multivariate normal distribution is asymptotically normal. Moreover a second-order approximation for the first moment is given.     

A model-based decision support system for solving vehicle routing and driver scheduling problems under hours of service regulations

In principle, hours-of-service (HOS) regulations are intended to help ensure truck drivers get adequate rest and perform safe operations. The new HOS regulations, however, may lead to substantial cost increases for regional common carriers which have already been hit hard by rising fuel prices and declining shipping demands. In addition, the new HOS regulations complicate driver schedules by not only restricting the driver's consecutive driving hours, but also expanding off-duty hours. To deal with this complex challenge, we propose a model-based decision support system (DSS) that helps determine the truck driver's working hours, rest periods, and his/her assigned truck's schedules and routes under HOS regulations. As a core of this model-based DSS, we developed a mixed-integer programming model and a simulated annealing metaheuristic for solving it. This model was also integrated with a geographical information system and relational database management system to enhance interfaces between the model and its parametric data using spatial, graphical displays.     

Social support and turnover among entry-level service employees: Differentiating type,source, and basis of attachment

Previous research on social support and turnover has yielded mixed results. To advance research in a more comprehensive manner, the present study examined how turnover is influenced by type of support (emotional or instrumental), source of support (coworker or supervisor), and basis of attachment (affective commitment and constituent attachment as mediators). In the context of entry-level service employees, these relationships were examined with a sample of restaurant servers company-wide from a casual dining restaurant chain in the USA. Coworker emotional support was directly and negatively related to turnover, and coworker instrumental support was directly and positively related to turnover. Furthermore, supervisor emotional support and instrumental support were indirectly related to turnover through affective commitment. When the mediators were considered independently, coworker and supervisor emotional support were both indirectly related to turnover through constituent attachment.     

A queueing problem with arrival and service in batches of variable size

This paper studies the transient behaviour of a single-channel queueing problem wherein (i) the input, following aPoisson distribution, is in batches of variable size (ii) the queue discipline is first-come-first-served; it being assumed that the batches are pre-ordered for service purposes (iii) the output, following a general distribution, is in batches of variable size. TheLaplace transform of the probability generating function of the waiting line size is obtained and the corresponding results are derived when the service time distribution is (i) hyper-exponential with m branches (ii) phase-type and (iii) exponential. Finally, some particular cases are discussed.     

Fair allocation in a general model with indivisible goods

In this paper we study the problem of fair allocation in economies with indivisible goods, dropping the usual restriction that one agent receives at most one indivisible good. We show that most of the results obtained in the literature do not hold when the aforementioned restriction is dropped. Received: 13 July 1995 / Accepted: 2 December 1997     

Resource allocations with guaranteed awards in claims problems

Review of Economic Design - The notion of lower bound on awards has been introduced in the literature to analyze the establishment of guarantees that ensure a minimum award to each agent involved...     

The relationship between HRM practices and service behaviour in South African service organizations

This paper reports on findings from research conducted in South African service organizations that frontline employees' perceptions of HRM practices have a direct influence on their service behaviour. Specific HRM practices have more impact than others and this was attributed to the influence of external factors such as the socio-political situation and national culture and to internal factors linked to the way managers implemented the HRM practices in the organization. Organizational commitment was found to play a mediating role in the relationship between frontline employees' perceptions of HRM and their service behaviour.     

Stable sets in matching problems with coalitional sovereignty and path dominance

We study von Neumann Morgenstern stable sets for one-to-one matching problems under the assumption of coalitional sovereignty (C), meaning that a deviating coalition of players does not have the power to arrange the matches of agents outside the coalition. We study both the case of pairwise and coalitional deviations. We argue further that dominance has to be replaced by path dominance (P) along the lines of van Deemen (1991) and Page and Wooders (2009). This results in the pairwise CP vNM set in the case of pairwise deviations and the CP vNM set in the case of coalitional deviations. We obtain a unique prediction for both types of stable sets: the set of matchings that belong to the core.