Priority Auctions and Queue Disciplines that Depend on Processing Time

Lecture on the first SFB/TR 15 meeting, Gummersbach, July, 18 - 20, 2004We analyze the allocation of priority in queues via simple bidding mechanisms. In our model, the stochastically arriving customers are privately informed about their own processing time. They make bids upon arrival at a queue whose length is unobservable. We consider two bidding schemes that differ in the definition of bids (these may reflect either total payments or payments per unit of time) and in the timing of payments (before, or after service). In both schemes, a customer obtains priority over all customers (waiting in the queue or arriving while he is waiting) who make lower bids. Our main results show how the convexity/concavity of the function expressing the costs of delay determines the queue-discipline (i.e., SPT, LPT) arising in a bidding equilibrium

Priority Auctions and Queue Disciplines that Depend on Processing Time

Lecture on the first SFB/TR 15 meeting, Gummersbach, July, 18 - 20, 2004We analyze the allocation of priority in queues via simple bidding mechanisms. In our model, the stochastically arriving customers are privately informed about their own processing time. They make bids upon arrival at a queue whose length is unobservable. We consider two bidding schemes that differ in the definition of bids (these may reflect either total payments or payments per unit of time) and in the timing of payments (before, or after service). In both schemes, a customer obtains priority over all customers (waiting in the queue or arriving while he is waiting) who make lower bids. Our main results show how the convexity/concavity of the function expressing the costs of delay determines the queue-discipline (i.e., SPT, LPT) arising in a bidding equilibrium.

Partnerships, Lemons and Efficient Trade

We analyze the possibility of efficient trade with informationally interdependent valuations and with a dispersed ownership. A crucial role is played by the sign of the derivatives that measure how valuation functions depend on others’ signals. If valuations are increasing functions of other agents’ signals, it is more difficult to achieve efficient trade with interdependent values than with private values (where the respective derivatives are zero.) In contrast, if valuations are decreasing functions of other agents’ signals, it is easier to achieve efficient trade with interdependent values. Our results unify and generalize the insights of Cramton et al. [1987], Myerson and Satterthwaite [1983], and Akerlof [1970].

Pengaruh Sikap Dan Motivasi Terhadap Komitmen Ahli Dalam Pelbagai Aktiviti Rukun Tetangga Di Kawasan R.T. Taman Sri Jelok, Kajang, Selangor

Tujuan utama kajian ini adalah untuk menjelaskan tahap komitmen anggota komuniti dalam aktiviti Rukun Tetangga Taman Sri Jelok, dan menjelaskan pengaruh sikap dan motivasi terhadap komitmen. Kajian ini juga adalah untuk mengenalpasti peramal terbaik untuk komitmen dan daripada kajian ini juga dapat dibentuk satu model komitmen bagi organisasi atau pertubuhan sukarela berbentuk kemasyarakatan. Dalam kajian ini, sampel yang digunakan adalah seramai 200 orang anggota komuniti yang menjadi ahli R.T. Tmn. Sri Jelok. Kajian ini merupakan kajian tinjauan menggunakan borang soal selidik. Data dikumpul menggunakan soal selidik yang mengandungi soalan berkaitan latar belakang, faktor sikap, faktor motivasi dan komitmen. Tahap komitmen anggota komuniti dalam aktiviti R.T. diukur dengan menggunakan soal selidik yang diadaptasi daripada soal selidik Organizatinal Commitment Questionaire (Poter et al. 1979). Manakala alat ukuran untuk pemboleh ubah sikap dan pemboleh ubah motivasi diukur dengan menggunakan soal selidik yang diadaptasi dan diubahsuai daripada soal selidik yang digunakan oleh Turiman (1991). Hasil kajian menunjukkan bahawa sikap dan komitmen kaum India terhadap aktiviti R.T. adalah tinggi berbanding dengan kaum Melayu dan Cina. Daripada analisis bivariate mendapati pemboleh ubah faktor sikap iaitu nilai-nilai instrumental, tarikan kepada aktiviti R.T., sikap terhadap aktiviti R.T. dan kepuasan terhadap aktiviti R.T. mempunyai hubungan positif dan signifikan dengan komitmen. Manakala empat daripada lima pemboleh ubah faktor motivasi iaitu altruisme, egoisme, keagamaan dan kewajipan sosial mempunyai hubungan positif dan signifikan dengan komitmen. Daripada analisis regresi pelbagai mendapati sebanyak 65% varian komitmen dalam aktiviti R.T. dapat dijelaskan oleh 9 pemboleh ubah daripada faktor sikap dan faktor motivasi. Manakala daripada analisis regresi ‘stepwise’ mendapati peramal terbaik bagi komitmen ialah nilai-nilai instrumental, tarikan daripada aktiviti R.T., sikap terhadap kegiatan dan aktiviti R.T. dan motivasi altruisme. Hasil kajian mendapati bahawa faktor sikap dan faktor motivasi memberi sumbangan yang besar kepada komitmen ahli-ahli dalam aktiviti R.T. Daripada dapatan kajian ini boleh disimpulkan komitmen ahli komuniti yang terlibat dalam aktiviti R.T. meningkat sekiranya tanggapan individu terhadap nilai-nilai instrumental R.T. adalah positif, lebih tertarik kepada aktiviti R.T., sikap positif dalam aktiviti R.T. dan sifat suka membantu (motivasi altruisme) dalam diri individu

Indentation of ultrathin elastic films and the emergence of asymptotic isometry

We study the indentation of a thin elastic film floating at the surface of a liquid. We focus on the onset of radial wrinkles at a threshold indentation depth and the evolution of the wrinkle pattern as indentation progresses far beyond this threshold. Comparison between experiments on thin polymer films and theoretical calculations shows that the system very quickly reaches the Far from Threshold (FT) regime, in which wrinkles lead to the relaxation of azimuthal compression. Furthermore, when the indentation depth is sufficiently large that the wrinkles cover most of the film, we recognize a novel mechanical response in which the work of indentation is transmitted almost solely to the liquid, rather than to the floating film. We attribute this unique response to a nontrivial isometry attained by the deformed film, and discuss the scaling laws and the relevance of similar isometries to other systems in which a confined sheet is subjected to weak tensile loads.Comment: 5 pages, close to published versio

Random forest application on cognitive level classification of E-learning content

The e-learning is the primary method of learning for most learners after the regular academics studies. The knowledge delivery through e-learning technologies increased exponentially over the years because of the advancement in internet and e-learning technologies. Knowledge delivery to some people would never have been possible without the e-learning technologies. Most of the working professional do focused studies for carrier advancement, promotion or to improve the domain knowledge. These learner can find many free e-learning web sites from the internet easily in the domain of interest. However it is quite difficult to find the best e-learning content suitable for their learning based on their domain knowledge level. User spent most of the time figuring out the right content from a plethora of available content and end up learning nothing. An intelligent framework using machine learning algorithms with Random Forest Classifier is proposed to address this issue, which classifies the e-learning content based on its difficulty levels and provide the learner the best content suitable based on the knowledge level .The frame work is trained with the data set collected from multiple popular e-learning web sites. The model is tested with real time e-learning web sites links and found that the e-contents in the web sites are recommended to the user based on its difficulty levels as beginner level, intermediate level and advanced level

Partnerships, lemons and efficient trade

We analyze the possibility of efficient trade with informationally interdependent valuations and with a dispersed ownership. A crucial role is played by the sign of the derivatives that measure how valuation functions depend on others’ signals. If valuations are increasing functions of other agents’ signals, it is more difficult to achieve efficient trade with interdependent values than with private values (where the respective derivatives are zero.) In contrast, if valuations are decreasing functions of other agents’ signals, it is easier to achieve efficient trade with interdependent values. Our results unify and generalize the insights of Cramton et al. [1987], Myerson and Satterthwaite [1983], and Akerlof [1970]

Nanotechnology—Applications in Prosthodontics: A Literature Review

Nanoscale particles are not new to nature or science. However, the recent leaps in areas, such as microscopy have given scientists new tools to understand and take advantage ofphenomena that occur naturally when matter is organized at the nanoscale. Nanotechnology is not simply working at ever smaller dimensions; rather, working at the nanoscale enablesscientists to utilize the unique physical, chemical, mechanical, and optical properties of materials that naturally occur at that scale. In this article, we have made an attempt to have an early glimpse on impact of nanotechnology in the field of dentistry