Clubs as status symbol: Would you belong to a club that accepts you as a member

We present a stylised model that goes beyond traditional analyses involving crowding and exclusiveness, and addresses the status issue by asking 'Do I want to be associated with those individuals?' rather than 'Do I want to be associated with that many individuals?'. As the population cares more about status, exclusion from well-defined groups/clubs occurs: less desirable individuals are refused. Inability to exclude induces the most desirable individuals to leave, and the club collapses. Offering honorary membership to the most desirable potential members is not only a commercially optimal strategy when exclusion is not allowed, it even outperforms exclusion as a revenue maximisation strategy

Dynamic Capacity Adjustments with Reactive Customers

In this paper we develop a behavioural model in which customers come and go based on their perception of waiting time (relative to other facilities) while managers gradually adjust the capacity of the facility based on their perception of demand. We explicitly account for the difference in access to information between existing and potential customers, which implies that the perception of potential customers lags the perception of current customers. We investigate the outcome of the interaction between these simultaneous dynamic decision processes, and in particular the impact of the lags created by the perception formation process and the time to implement desired changes in capacity. These multiple delays may result in customers and service provider being out of step: customers walk away just as the service provider manages to bring extra capacity online

Mode Locking and Chaos in a Deterministic Queueing Model with Feedback

We consider a simple, deterministic queueing system with feedback, which exhibits the phenomena of sustained oscillation, mode locking, quasi-periodic behaviour, and chaos. This implies that a fully deterministic queueing system can exhibit seemingly unpredictable behaviour. We ignore variability, and focus on two forms of feedback: (i) the service rate increases as queue length increases, and (ii) the arrival rate depends on customers' perception of past waiting times. We model a customer's decision to seek service as a two-stage process: (i) deciding whether or not to use a facility, and (ii) deciding the frequency of visit (daily, weekly, monthly, etc.). This frequency is initially constant, and later on replaced by a deterministic, time-dependent pattern. Although highly stylised, this model captures the essential features of many real-life systems whose average arrival rate varies over time. Reducing the amplitude of cycles in demand makes the system more predictable and thus easier to manage. Although we represent this model as a queue of customers waiting for service, the model can be interpreted more generally as any situation where an increase in demand lowers the quality of service

Long and short term customer reaction: a two-stage queueing approach

We analyse a simple, deterministic queueing system with feedback. We model a customer's decision to seek service as a two-stage process: (1) deciding whether or not to use a facility (become a customer), and (2) deciding the frequency of use (daily, weekly, monthly, etc.). We consider both a constant and a deterministic, time-dependent usage pattern. We ignore variability, and focus on three forms of feedback: (1) the service rate increases as queue length increases; (2) the frequency with which customers use the service depends on customers' perception of recent waiting times; and (3) the number of customers depends on their perception of long-term average waiting time. Although highly stylised, this model captures the essential features of many real-life systems whose average arrival rate varies over time. The main conclusions are that more capacity can make the system less manageable, and a stronger external cycle can be a stabilising factor. The model turns out to be remarkably robust to external disturbances

Mikromekaanisen resonaattorirakenteen ohjaus ohjelmoitavaan logiikkapiiriin perustuvalla järjestelmällä

Tämä diplomityö käsittelee mikromekaanisen kulmanopeusanturielementin liikkeen ohjaukseen käytettävän ohjelmoitavaan logiikkapiiriin perustuvan testausjärjestelmän kehittämistä ja toteuttamista. Järjestelmä on kehitetty VTI Technologies:lla toteuttaen uuden tyyppinen testausjärjestelmä ja sen tarkoitus on korvata nykyisin käytössä oleva monilta osin rajoittunut testausjärjestelmä. Teoriaosuudessa esitellään kaksiakselisen kulmanopeusanturielementin rakenne, toimintaperiaate ja elementin toimintaan vaikuttavat epäideaalisuudet. Lisäksi tarkastellaan erilaisia vaihtoehtoisia resonaattorirakenteen ohjausmenetelmiä. Testausjärjestelmän rakenne ja ohjelmiston toiminta käydään läpi. Ohjelmiston oleellisimmat rakennelohkot ja toteutus esitellään yksityiskohtaisesti. Lisäksi esitellään ohjelmointiin käytetyn ohjelmointikielen perusteet. Toteutetun testausjärjestelmän toimintaa on verrattu käytössä olevaan testausjärjestelmään. Järjestelmän ohjelmallista muokattavuutta on havainnollistettu karakterisoimalla korkeampien taajuusalueiden liikemoodeja sekä mittaamalla epälineaarisia jousivakioita. Järjestelmän mittauskyvykkyys on todettu riittäväksi, jotta sillä voidaan tulevaisuudessa korvata nykyinen nykyinen testausjärjestelmä