Approximate performance analysis of generalized join the shortest queue routing

In this paper we propose a highly accurate approximate performance analysis of a heterogeneous server system with a processor sharing service discipline and a general job-size distribution under a generalized join the shortest queue (GJSQ) routing protocol. The GJSQ routing protocol is a natural extension of the well-known join the shortest queue routing policy that takes into account the non-identical service rates in addition to the number of jobs at each server. The performance metrics that are of interest here are the equilibrium distribution and the mean and standard deviation of the number of jobs at each server. We show that the latter metrics are near-insensitive to the job-size distribution using simulation experiments. By applying a single queue approximation we model each server as a single server queue with a state-dependent arrival process, independent of other servers in the system, and derive the distribution of the number of jobs at the server. These state-dependent arrival rates are intended to capture the inherent correlation between servers in the original system and behave in a rather atypical way.Comment: 16 pages, 5 figures -- version 2 incorporates minor textual change

Ed Talks: A Collaborative Professional Development Partnership

The purpose of the current manuscript is to delineate a collaborative professional development effort between Coastal City Public Schools and Ocean View University—a nascent school-university partnership. Ed Talks were created to build relationships between public school and university faculty but we have encountered challenges in implementing this effort including scheduling issues. However, the effort has been supported by teacher leadership and technology. While our partnership is still growing, Ed Talks have been a catalyst for building informal relationships between Eagle Academy and Ocean View University faculty

Steady-state analysis of shortest expected delay routing

We consider a queueing system consisting of two non-identical exponential servers, where each server has its own dedicated queue and serves the customers in that queue FCFS. Customers arrive according to a Poisson process and join the queue promising the shortest expected delay, which is a natural and near-optimal policy for systems with non-identical servers. This system can be modeled as an inhomogeneous random walk in the quadrant. By stretching the boundaries of the compensation approach we prove that the equilibrium distribution of this random walk can be expressed as a series of product-forms that can be determined recursively. The resulting series expression is directly amenable for numerical calculations and it also provides insight in the asymptotic behavior of the equilibrium probabilities as one of the state coordinates tends to infinity.Comment: 41 pages, 13 figure

Reusable generic software robot

Abstract. The main purpose of this thesis was to create a generic reusable software robot which can be deployed into any IaaS type of a cloud service. In this thesis the first thing to be researched was how to implement a virtualised environment into a cloud service. The possibilities for virtualising the environment were a container and a virtual machine. The two possible implementations were researched since the resulting implementation must be compatible with a cloud service. Firstly, it was found that a container-based implementation would be the best option because it is lightweight to move around and secondly, a start-up time of a new instance in a cloud service is fast. Possible cloud providers were scanned after researching possible implementation methods. Two possible cloud providers, AWS and Azure, were studied more closely since they offer an infrastructure as a service and once they are commonly used. AWS was chosen to be the platform to be used because of a higher maturity level and also because of the possibility to add or remove container capabilities. Finally, it was discussed how a generic reusable software robot was implemented. Notable circumstances of suitable tasks for a software robot were considered.Kertakäyttöinen geneerinen ohjelmistorobotti. Tiivistelmä. Tässä työssä tutkittiin, kuinka geneerinen kertakäyttöinen ohjelmistorobotti voidaan toteuttaa pilvipalvelussa. Ensin tarkasteltiin erilaisia virtualisointimenetelmiä, joilla ohjelmistorobotti voitaisiin toteuttaa. Tutkitut menetelmät olivat virtuaalikone ja kontti. Näitä kahta toteutustapaa vertailtiin huomioiden valmiin toteutuksen sopivuus pilvipalveluun. Kontti todettiin sopivimmaksi toteutustavaksi, koska se vie vähän tilaa ja uuden instanssin käynnistäminen on nopeaa. Pilvipalvelutarjoajia tutkittiin, kun sopiva toteutusmenetelmä ohjelmistorobotille oli löydetty. Tutkimuksessa keskityttiin AWS:ään ja Azureen, jotka ovat tällä hetkellä suurimpia markkinoilla toimivia infrastructure as a service -tyyppisten pilvipalveuiden tarjoajia. AWS valittiin toteutusalustaksi, koska se on teknisesti edistyneempi kuin Azure ja AWS:ssä on mahdollista lisätä ja poistaa kontin oikeuksia. Lopuksi esiteltiin, kuinka geneerinen kertakäyttöinen ohjelmistorobotti toteutettiin ja mitä täytyy ottaa huomioon, kun päätetään sopivasta käyttökohteesta ohjelmistorobotille

Building Community Through Asset Mapping in an Alternate Route to Licensure Program

Teacher preparation programs in the U.S. have adopted social justice approaches in their work. However, it is necessary to investigate how teacher preparation programs foster an asset orientation in teacher candidates—particularly as Alternative Routes to Licensure have increased in popularity. The current investigation was an interview study of teacher candidates’ experiences after completing an asset mapping activity as part of their field experiences. Participants consistently described how the activity helped them to foster relationships with their students through (a) making connections, (b) humanizing students, and (c) community scaffolding. We explore the implications of these findings for teacher preparation research and practice

Treatment of travellers' diarrhoea with fleroxacin: a case study

A double-blind, randomized, placebo-controlled trial was conducted to evaluate the efficacy and safety of fleroxacin for one or two days as treatment for patients with travellers' diarrhoea. A total of 195 patients who were suffering with acute diarrhoea of less than six days' duration were enrolled. One hundred and fifty-one patients, of whom 49 received placebo, 54 received fleroxacin 400 mg for one day and 48 received fleroxacin 400 mg for two days, were included in the analysis of efficacy. The results showed that fleroxacin was significantly superior to placebo, but that there was no significant difference in terms of efficacy between the one- and two-day regimens. Adverse events, particularly minor neuropsychiatric disturbances such as headache and insomnia, were significantly more common amongst patients receiving active treatment. In conclusion, a single dose of fleroxacin 400 mg could be recommended as self-treatment for visitors to high-risk countries who develop travellers' diarrhoe