626 research outputs found
Making Large Classes Small(er): Assessing the Effectiveness Of a Hybrid Teaching Technology
This paper examines learning outcomes in a one-semester introductory microeconomics course where contact time with the instructor was reduced by two-thirds and students were expected to view pre-recorded lectures on-line and come to class prepared to engage in discussion. Students were pre-and post-tested using the Test of Understanding in College Economics (TUCE - 4). Learning outcomes as measured by the change in test scores are found to be as good as or better than calibrating data for groups assessed using the TUCE - 4. In addition to being a more enjoyable course for the instructor, the course design can be part of a more self-directed curriculum that uses available resources more efficiently to achieve similar learning objectives to a lecture-based introductory course.active learning, assessment, computer-assisted instruction, introductory microeconomics
The Value of RFID Technology Enabled Information to Manage Perishables
We address the value of RFID technology enabled information to manage perishables in the context of a supplier that sells a random lifetime product subject to stochastic demand and lost sales. The product's lifetime is largely determined by the time and temperature history in the supply chain. We compare two information cases to a Base case in which the product's time and temperature history is unknown and therefore its shelf life is uncertain. In the first information case, the time and temperature history is known and therefore the remaining shelf life is also known at the time of receipt. The second information case builds on the first case such that the supplier now has visibility up the supply chain to know the remaining shelf life of inventory available for replenishment. We formulate these three different cases as Markov decision processes, introduce well performing heuristics of more practical relevance, and evaluate the value of information through an extensive simulation using representative, real world supply chain parameters.simulation;value of information;RFID;perishable inventory
Optimal Distributed Power Generation Under Network-Load Constraints
In electrical power networks nowadays more and more customers are becoming power-producers, mainly because of the development of novel components for decentralized power generation (solar panels, small wind turbines and heat pumps). This gives rise to the question how many units of each type (solar panel, small wind turbine or central heating power units) can be inserted into any transmission line in the network, such that under given distributions on the typical production and consumption over time, the maximum loads on the lines and components will not be exceeded.
In this paper, we present a linear programming model for maximizing the amount
of decentralized power generation while respecting the load limitations of the
network.
We describe a prototype showing that for an example network the maximization
problem can be solved efficiently. We also modeled the case were the power consumption and decentralized power generation are considered as stochastic variables, which is inherently more complex
Wavefront sensing of atmospheric phase distortions at the Palomar 200-in. telescope and implications for adaptive optics
Major efforts in astronomical instrumentation are now being made to apply the techniques of adaptive optics to the correction of phase distortions induced by the turbulent atmosphere and by quasi-static aberrations in telescopes themselves. Despite decades of study, the problem of atmospheric turbulence is still only partially understood. We have obtained video-rate (30 Hz) imaging of stellar clusters and of single-star phase distortions over the pupil of the 200" Hale telescope on Palomar Mountain. These data show complex temporal and spatial behavior, with multiple components arising at a number of scale heights in the atmosphere; we hope to quantify this behavior to ensure the feasibility of adaptive optics at the Observatory. We have implemented different wavefront sensing techniques to measure aperture phase in wavefronts from single stars, including the classical Foucault test, which measures the local gradient of phase, and the recently-devised curvature sensing technique, which measures the second derivative of pupil phase and has formed the real-time wavefront sensor for some very productive astronomical adaptive optics. Our data, though not fast enough to capture all details of atmospheric phase fluctuations, provide important information regarding the capabilities that must be met by the adaptive optics system now being built for the 200" telescope by a team at the Jet Propulsion Lab. We describe our data acquisition techniques, initial results from efforts to characterize the properties of the turbulent atmosphere at Palomar Mountain, and future plans to extract additional quantitative parameters of use for adaptive optics performance predictions
Longing for God
To thirst for God, to seek after His teachings and long for His presence, is to adopt the posture of the psalmist in Psalm 119.
Posting about ÂÂÂÂÂÂÂÂacknowledging our need for God from In All Things - an online journal for critical reflection on faith, culture, art, and every ordinary-yet-graced square inch of God’s creation.
http://inallthings.org/longing-for-god
Directing Your Praise
God does not seek a mere performance, but a pressing effort to worship Him in all we do.
Posting about authentic praise from In All Things - an online hub committed to the claim that the life, death, and resurrection of Jesus Christ has implications for the entire world.
http://inallthings.org/directing-your-praise
Not What My Hands Have Done
We know that we are called to live differently than the world, to live in a way that is set apart from those who live as if they are their own gods.
Posting about stepping out into a hurting world from In All Things - an online journal for critical reflection on faith, culture, art, and every ordinary-yet-graced square inch of God’s creation.
https://inallthings.org/not-what-my-hands-have-done
Ready to Move, Resting in Faith
God promises to orchestrate His world in such a way that all things happen for the good of those who love Him.
Posting about trusting in God\u27s plan for our future from In All Things - an online journal for critical reflection on faith, culture, art, and every ordinary-yet-graced square inch of God’s creation.
http://inallthings.org/ready-to-move-resting-in-faith
Het vraagstuk der bewuste geboortebeperking:een onderzoek naar het standpunt van de Protestants-Christelijke ethiek inzake het toepassen van anticonceptie in verband met de veranderende maatschappelijke omstandigheden
Design of Closed Loop Supply Chains
Increased concern for the environment has lead to new techniques to design products and supply chains that are both economically and ecologically feasible. This paper deals with the product - and corresponding supply chain design for a refrigerator. Literature study shows that there are many models to support product design and logistics separately, but not in an integrated way. In our research we develop quantitative modelling to support an optimal design structure of a product, i.e. modularity, repairability, recyclability, as well as the optimal locations and goods flows allocation in the logistics system. Environmental impacts are measured by energy and waste. Economic costs are modelled as linear functions of volumes with a fixed set-up component for facilities. We apply this model using real life R&D data of a Japanese consumer electronics company. The model is run for different scenarios using different parameter settings such as centralised versus decentralised logistics, alternative product designs, varying return quality and quantity, and potential environmental legislation based on producer responsibility.supply chain management;reverse logistics;facility location;network design;product design
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