Spelling suggestions: "subject:"demand"" "subject:"demandem""
341 |
The demand for Divisia money /Chou, Nan-Ting January 1986 (has links)
No description available.
|
342 |
The demand analysis for four major milk and dairy products in the United States : an application of logistic microdata approach /Wu, Ming-Ming January 1986 (has links)
No description available.
|
343 |
Understanding Bike Share Usage: An Investigation of SoBi (Social Bicycles) HamiltonCiuro, Celenna January 2017 (has links)
This thesis examines factors that influence the daily number of trip departures and
arrivals at over 100 hubs comprising Hamilton, Ontario’s (Canada) bike share program
– SoBi (Social Bicycles) Hamilton. SoBi operates all year, and during its first year of
operation (April 1, 2015 to March 31, 2016), over 200,000 trips were generated on SoBi
bikes. The study utilizes data from SoBi Hamilton, the 2011 Canadian Census, the 2011
Transportation Tomorrow Survey, Environment Canada, and Hamilton’s Open Source
Data initiative. From these master files, daily trips, meteorological data, temporal
variables, socio-demographic and built environment attributes were obtained to generate
a comprehensive suite of explanatory variables to explain the daily trips at each hub. A
multilevel regression approach was used to understand the associations between bike
share usage at each hub and each suite of explanatory variables at two temporal scales:
total daily trips at hubs and total daily trips across four time periods of the day. Findings
demonstrate that weather and temporal attributes play a significant role in trip departures
and arrivals. In addition, hub attributes vary in significance throughout different times of
the day for trip departures and arrivals. Overall, the methodology and findings allow us
to identify factors that increase SoBi usage, which can also benefit city planners and
engineers who are implementing a bike share system with the goal of maximizing bike
share activity in urban centers. / Thesis / Master of Science (MSc)
|
344 |
An Expert-based Approach for Demand Curtailment Allocation Subject to Communications and Cyber Security LimitationsBian, Desong 03 February 2017 (has links)
A smart grid is different from a traditional power system in that it allows incorporation of intelligent features and functions, e.g., meter reading, adaptive demand response, integration of distributed energy sources, substation automation, etc. All these intelligent features and functions are achieved by choosing appropriate communication technologies and network structures for the smart grid appropriately.
The objective of this dissertation is to develop an AHP (analytic hierarchy process) - based strategy for demand curtailment allocation that is subject to communications and cyber security limitations. Specifically, it: (1) proposes an electrical demand curtailment allocation strategy to keep the balance between supply and demand in case of the sudden supply shortage; (2) simulates the operation of the proposed demand curtailment allocation strategy considering the impact from communication network limitations and simultaneous operations of multiple smart grid applications sharing the same communication network; and (3) analyzes the performance of the proposed demand curtailment allocation strategy when selected cyber security technologies are implemented. These are explained in more details below.
An AHP-based approach to electrical demand curtailment allocation management is proposed, which determines load reduction amounts at various segments of the network to maintain the balance between generation and demand. Appropriate communication technologies and the network topology are used to implement these load reduction amounts down to the end-user. In this proposed strategy, demand curtailment allocation is quantified taking into account the demand response potential and the load curtailment priority of each distribution substation. The proposed strategy helps allocate demand curtailment (MW) among distribution substations or feeders in an electric utility service area based on requirements of the central load dispatch center.
To determine how rapidly the proposed demand curtailment strategy can be implemented, the capability of the communication network supporting the demand curtailment implementation needs to be evaluated. To evaluate the capability of different communication technologies, selected communication technologies are compared in terms of their latency, throughput, reliability, power consumption and implementation costs. Since a number of smart grid applications share the same communication network, the performance of this communication network is also evaluated considering simultaneous operation of popular smart grid applications.
Lastly, limitations of using several cyber security technologies based on different encryption methods - 3EDS (Triple Data Encryption Standard), AES (Advanced Encryption Standard), Blowfish, etc. - in deploying the proposed demand curtailment allocation strategy are analyzed. / Ph. D.
|
345 |
Comparison of Microscopic and Mesoscopic Traffic Modeling Tools for Evacuation AnalysisAljamal, Mohammad Abdulraheem 15 March 2017 (has links)
Evacuation processes can be evaluated using different simulation models. However, recently, microscopic simulation models have become a more popular tool for this purpose. The objectives of this study are to model multiple evacuation scenarios and to compare the INTEGRATION microscopic traffic simulation model against the MATSim mesoscopic model. Given that the demand was the same for both models, the comparison was achieved based on three indicators: estimated evacuation time, average trip duration, and average trip distance. The results show that the estimated evacuation times in both models are close to each other since the Origin-Destination input file has a long tail distribution and so the majority of the evacuation time is associated when travelers evacuate and not the actual evacuation times. However, the evaluation also shows a considerable difference between the two models in the average trip duration. The average trip duration using INTEGRATION increases with increasing traffic demand levels and decreasing roadway capacity. On the other hand, the average trip duration using MATSim decreases with increasing traffic demand and decreasing the roadway capacity. Finally, the average trip distance values were significantly different in both models. The conclusion showed that the INTEGRATION model is more realistic than the MATSim model for evacuation purposes. The study concludes that despite the large execution times of a microscopic traffic simulation, the use of microsimulation is a worthwhile investment. / Master of Science
|
346 |
Capacitated, unbalanced p-median problems on a chain graph with a continuum of link demandsRizzo, Thomas Philip January 1986 (has links)
This study is concerned with the problem of locating p capacitated facilities on a chain graph, and simultaneously determining the allocation of their supplies in order to satisfy a continuum of demand which is characterized by some weighted probability density function defined on the chain graph. The objective is to minimize the total (expected) transportation cost. This location-allocation problem is also referred to as the capacitated p-median problem on a chain graph. Two unbalanced cases of this problem are considered, namely, the over-capacitated case when total supply exceeds total demand, and the deficit capacity case when total supply is less than total demand. Both these problems are nonconvex, and are shown to be NP-hard even if the demand density function is piecewise uniform and positive. We provide a first-order characterization of optimality for these two problems, and prescribe an enumerative algorithm based on a partitioning of the dual space in order to optimally solve them. An extension of these algorithms for solving the capacitated, unbalanced 2-median problem on a tree graph is also given. / M.S.
|
347 |
Essays in Industrial Organization:Palit, Arnab January 2024 (has links)
Thesis advisor: Michael Grubb / Thesis advisor: Charles Murry / This dissertation consists of two self-contained papers that explore the Industrial Organization of the UK television broadcasting market and broadband procurement by US K-12 schools Chapter 1: Welfare Effects of Competition in the UK Television Broadcasting Market In this chapter, I study the consumer welfare effects of a regulation that ended the exclusivity of telecast rights of live English Premier League games and induced entry into the UK television broadcasting market. Historically rights were owned by a single broadcaster. The regulation divided the games into mutually exclusive bundles and stipulated that a single broadcaster cannot own rights to all of them. This resulted in a new channel entering the market and showing some games. I estimate a model of household viewing preferences, channel subscription demand, and pricing using proprietary viewing and subscription choice data. Simulations show a 6.4\% (\pounds 10m per season) decline in consumer surplus driven by the higher prices consumers had to pay to view all the live games. This offset increased surplus from new content on the entrant channel. I propose an alternate regulation that breaks the exclusivity of games telecast on a channel and show that the estimated surplus could have been 29\% higher. Chapter 2: Bundling Demand in K-12 Broadband Procurement In this chapter coauthored with Gaurab Aryal, Charles Murry and Pallavi Pal, we evaluate the effects of bundling demand for broadband internet by K-12 schools. In 2014, New Jersey switched from decentralized procurements to a new procurement system that bundled schools into four regional groups. Using an event study approach, we find that, on average, prices for participants decreased by one-third, and broadband speed purchased increased sixfold. We bound the change in school expenditures due to the program and find that participants saved at least as much as their total ``E-rate" subsidy from the federal government. Under weak assumptions on demand, we show that participating schools experienced large welfare gains. Using an informal model and simulations, we analyze the main mechanisms that could lead to lower prices in the regional auctions. / Thesis (PhD) — Boston College, 2024. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Economics.
|
348 |
US Labor Demand: a Discourse Analysis on the "Hidden Force" behind Illegal ImmigrationCooper, Jeffrey T. 26 February 2008 (has links)
The dominant ideology within the illegal immigration discourse in the US primarily faults illegal workers for the problem by highlighting the act of illegally entering the US as the origin of the problem. As the dominant ideology goes, illegal immigrants evade law enforcement at the border; they deceive employers to secure work. They disrupt labor markets by lowering wages which displaces lower class US workers. The illegal immigrants and their families abuse social services that they do not pay into at the US taxpayers expense. They form ethnic enclaves, and those who remain in the US resist assimilation into US culture. So the story goes. This thesis challenges this dominant ideology, a subset of the illegal immigration discourse, by documenting decades of immigration law in the US created to serve US employers' demand for labor, and alternately, closing the immigrant worker pipeline when it suited the government's political objectives or the special interests of employers. Loopholes in the immigration laws have tended to insulate employers from prosecution. Meanwhile, undocumented workers have faced lower wages and increased risk. This thesis examines what constitutes the dominant ideology of the illegal immigration discourse. It also includes a discourse analysis of illegal immigration by reviewing national, regional, and local media coverage of the simultaneous raids in December 2006 of six Midwest meat processing plants operated by Swift & Company. The discourse analysis explores media coverage of the raids conducted by the Department of Homeland Security's Bureau of Immigration and Customs Enforcement (ICE). The raids led to the arrest of 1,282 suspected illegal immigrants, and the analysis will attempt to understand to what extent media coverage supports or challenges the dominant ideology of the illegal immigration discourse. / Master of Arts
|
349 |
Modeling and Simulation of a Video-on-Demand Network Implementing Adaptive Source-Level Control and Relative Rate Marking Flow Control for the Available Bit Rate ServiceTaylor, Elvin Lattis Jr. 16 January 1998 (has links)
The Available Bit Rate (ABR) service class for the Asynchronous Transfer Mode (ATM) protocol was originally designed to manage data traffic. ABR flow control makes no guarantees concerning cell transfer delay or cell delay variation. A closed-loop feedback mechanism is used for traffic management. To use this class of service for video transport, the video source will accept feedback from the network and adapt its source rate based on this status information. The objective of this research is to assess the ability of the ATM ABR service class to deliver Moving Picture Experts Group version 1 (MPEG-1) video. Three approaches to source-level control are compared: (i) arbitrary loss or no control method, (ii) selective discard of MPEG B-pictures, and (iii) selective discard of MPEG B- and P-pictures. Performance is evaluated based on end-to-end delay, congested queue occupancy levels, network utilization, and jitter. A description of the investigation, assumptions, limitations, and results of the simulation study are included. / Master of Science
|
350 |
Understanding the Limits of Residential Water Conservation through Generalized, Basin-Scale System DynamicsWinter, Benjamin Frederick 03 July 2023 (has links)
Population growth and climate change have strained existing water supplies requiring municipalities to shift towards demand management strategies to ensure reliable water provisions. Particularly in the residential sector, water conservation measures and incentives have been utilized to reduce demand during short-term shortages. As water conservation programs are now being commonly utilized as a way to ensure enough water will be available for continued growth, the impacts on a basin-wide scale have yet to be established. By changing the relative water demand for indoor and outdoor uses within a municipality, the amount of water being consumed can thereby reduce the effluent available for downstream communities. This research investigates how the timing of water conservation, water conservation strategy, and population growth impact water availability in a shared basin. A generalized system dynamics model reflecting typical residential water use and availability patterns similar to the southwest United States was utilized. We found that when upstream municipalities focus their initial reductions on non-consumptive demands, downstream municipalities reliant on upstream return flow have to increase their conservation rate to meet demands and maintain population growth. When most of the basin's population is in upstream municipalities, the more influence their change in water use has on downstream water availability. Therefore, consumptive conservation should be the priority of basin-wide conservation programs to ensure return flow is sufficient to satisfy the demands of downstream municipalities. / Master of Science / Population growth and climate change have reduced water supplies for many cities across the United States. This has led to increased water conservation at the household level to reduce the amount of water needed for everyday uses. Efforts like reduced lawn watering and shorter showers have been helpful during short-term dry spells but more cities are using long-term strategies like high efficiency appliances and the removal of green lawns to "free up" enough water for population growth. However, these changes in water use can impact how much water returns to the river and goes downstream for the next city to use. This research looks at how changes in the speed of water conservation, water conservation strategy, and population impacts water availability in a shared basin. Our stylized model reflects typical residential water use and availability patterns similar to the southwest United States. We found that the faster cities within a basin reduce their indoor water use, the greater downstream cities have to reduce their water use in order to have enough available water to meet demands. Also, when most of the basin's population is in upstream cities, the harder it is for the downstream city to have enough water to maintain target population growth. However, reducing outdoor water use first is the best way for every city that shares the same river to stay satisfied.
|
Page generated in 0.0923 seconds