Generalized selfish bin packing

Standard bin packing is the problem of partitioning a set of items with positive sizes no larger than 1 into a minimum number of subsets (called bins) each having a total size of at most 1. In bin packing games, an item has a positive weight, and given a valid packing or partition of the items, each item has a cost or a payoff associated with it. We study a class of bin packing games where the payoff of an item is the ratio between its weight and the total weight of items packed with it, that is, the cost sharing is based linearly on the weights of items. We study several types of pure Nash equilibria: standard Nash equilibria, strong equilibria, strictly Pareto optimal equilibria, and weakly Pareto optimal equilibria. We show that any game of this class admits all these types of equilibria. We study the (asymptotic) prices of anarchy and stability (PoA and PoS) of the problem with respect to these four types of equilibria, for the two cases of general weights and of unit weights. We show that while the case of general weights is strongly related to the well-known First Fit algorithm, and all the four PoA values are equal to 1.7, this is not true for unit weights. In particular, we show that all of them are strictly below 1.7, the strong PoA is equal to approximately 1.691 (another well-known number in bin packing) while the strictly Pareto optimal PoA is much lower. We show that all the PoS values are equal to 1, except for those of strong equilibria, which is equal to 1.7 for general weights, and to approximately 1.611824 for unit weights. This last value is not known to be the (asymptotic) approximation ratio of any well-known algorithm for bin packing. Finally, we study convergence to equilibria

More Than a Meal: Pilot Research Study

The national Meals on Wheels network continues to face limited funding, rising costs, unprecedented demand and need and increasing for-profit competition. That is why Meals on Wheels America set out to compare the experience and health outcomes realized by older adults who receive three different levels of service: daily traditional meal delivery, once-weekly frozen delivery and individuals on a waiting list. This study, funded by AARP Foundation and conducted by researchers at Brown University, implemented a groundbreaking approach to investigating the impact of meal service delivery on homebound seniors receiving Meals on Wheels. The study's findings validate what we've all known for decades anecdotally through firsthand experience: that Meals on Wheels does in fact deliver so much more than just a meal

Technology utilization program report, 1974

The adaptation of various technological innovations from the NASA space program to industrial and domestic applications is summarized

Compressed Air Network Calculus Using Computer Program

This paper presents the results obtained in developing a computer program for the calculus of compressed air network

A Soft-Switched Three-Port DC-DC Converter for a PV/ Battery System

This thesis proposed a soft-switched three-port bidirectional DC-DC converter for managing the power flow of a photovoltaic (PV) and battery system. The proposed converter consists of three ports connected to a PV panel, battery, and load. These three ports are interfaced through the high-frequency transformer and use phase-shift control to achieve soft-switching for all converter switches. Compared with the traditional multiport converters, the proposed three-port converter uses the least number of power switches, and zero-voltage switching (ZVS). Simulation and experimental results validate the design and effectiveness of soft switching and power flow control. The converter can work in different scenarios regardless of the availability of renewable energy and the battery\u27s state of charge. In addition, maximum power point tracking (MPPT) for renewable energy sources can be achieved for the renewable energy source while managing the power flow between three ports

Power Plant Waste Heat Recovery for Household Heating Using Heat Pumps

This paper presents a model of a power plant condenser cooling circuit which has in addition to the classical cooling scheme heat pumps for waste heat recovery. Major source of loss for a thermal power plant is the heat rejected by the condenser which can be up to 48.9% of thermal energy at turbine inlet, depending on technology used for power generation. Heat rejected by the cooling water of condenser will end up in the environment through the use of a cooling tower or directly in rivers depending on the cooling scheme employed, producing thermal pollution. Based on the mathematical model, a study on the effect of heat recovery using power plant waste heat as heat source for heat pumps was carried out. The reference heat source temperature for the heat pump was 5 °C, while the condenser cooling water temperature at outlet was in the range of 22.96 °C in April to 14.99 °C in December. As expected high cooling water temperatures at condenser outlet will generate the highest practical COP which is 3.35 comparative to 2.84 for the reference case. Accordingly the smallest amount of work that needs to be supplied to the heat pump is 8.359 kW comparative to 9.861 kW for the reference case, resulting 1.502 kW savings. For the heating period from October to April the worst case scenario is for the temperatures in December when temperature of water at the outlet of condenser was minimal 14.99 °C. Even in this case, practical COP is 3.11 higher than 2.84 for reference case, and the amount of savings with the work supplied to heat pump is 0.869 kW. In closed loop operation, the temperature of returned water at the steam condenser inlet can be theoretically 5 °C (temperature at the outlet of heat pump evaporator) with all the benefits resulting from proper condenser cooling

Nanostructured ceria-based catalysts for automotive application - Formulation of nanostructured systems for diesel and gasoline-type engines

L'abstract è presente nell'allegato / the abstract is in the attachmen

Hudfärg, etnicitet eller ursprung? Om funktionell översättning av ordet race i en bok om amerikansk scenkonst

Denna magisteruppsats baseras på en översättning av ett utdrag ur den amerikanske professorn och litteraturkritikern Edward Margolies bok New York and the literary imagination: the city in twentieth century fiction and drama. Uppsatsen inleds med en källtextanalys som utgår från Lennart Hellspong och Per Ledins metod i Vägar genom texten: Handbok i brukstextanalys (1997). Därefter följer ett kapitel om överväganden inför översättningen som behandlar kulturanpassning samt den globala och de lokala översättningsstrategierna. Den globala strategin har varit funktionell och de lokala lösningarna som använts har varit bruksmotsvarighet, implicitgörande, explicitering och modulation. Sedan följer en fördjupningsdel som analyserar hur det engelska ordet race har överförts till en svensk kontext. Uppsatsen visar att utmaningarna vid översättning av ordet race till svenska främst ligger i stora skillnader mellan den amerikanska och den svenska användningen av orden race respektive ras