Analysis of a polling system modeling QoS differentiation in WLANs

This paper investigates a polling system with a random polling scheme, a 1-limited service discipline and deterministic service requirement modeling WLANs with QoS differentation capability. The system contains high and low priority queues that are distinguished via the probability of being served next. We propose a new iteration algorithm to approximate the waiting time of customers in the high and low priority queues. As shown by simulation results, our approximation is accurate for light to moderately loaded networks

Disease suppression of potting mixes amended with composted biowaste

Peat mining destroys valuable nature areas and contributes to the greenhouse effect. This warrants the search for alternatives for peat in potting mixes. Composted biowaste could provide such an alternative. An additional advantage of (partially) replacing peat by compost is the increased disease suppressiveness. In this study, nine commercial composted biowastes were tested for disease suppressiveness using the pathosystems Pythium ultimum-cucumber, Phytophthora cinnamomi-lupin and Rhizoctonia solani-carrot. Increased disease suppression was found in compost-amended potting mixes for all three pathosystems. The level of disease suppression ranged from slight stimulation of disease to strong suppression. Suppressiveness against one disease was not well correlated with that against the other diseases. The CO2 production, a measure of general microbial activity, was the parameter most strongly correlated with the level of disease suppression. Wetsieving the biowaste with tap water over a 4-mm sieve prior to composting yielded a compost with an 2.4-fold increase in organic matter and a twofold decrease in EC and Cl--concentration of the compost. The latter reductions allow for an increase of the amount of peat that can be replaced by compost. A linear relation was found between the amount of compost added to the potting mix and the level of disease suppression indicating the potential for increasing disease suppressiveness of potting mixes by replacing peat by high-quality composted biowastes

Congressional Power over Presidential Elections: Lessons from the Past and Reforms for the Future

Presidential election controversies are nothing new. They have plagued our republic since 1801, when the fourth election for the office ended in a muddle that nearly deprived the rightful winner of the presidency. Each controversy has led to calls for reform. In every instance, the cryptic and troublesome constitutional text has hampered congressional efforts to correct the problems. Simply stated, the Constitution offers little explicit guidance on when and how Congress can regulate the selection of the President. In this Article, we explore the implications of this textual deficiency, looking both at what Congress has done in the past and at what it might do now. Our analysis proceeds in five steps. Part I of our Article highlights relevant features of the constitutional text. Part II explores how Congress reluctantly but successfully used this text to enact significant reform legislation in response to the Hayes-Tilden election debacle of 1876. Part III identifies some reforms that Congress has under consideration to address the problems that complicated the 2000 presidential vote, focusing on measures that would lead to nationwide use of a uniform ballot and federally approved voting devices and machinery. Part IV then examines whether Congress has the power to enact these measures, concluding (in an analysis that covers six possible sources of authority) that it does. Part V urges Congress to wield this power by enacting significant reform legislation in time for the 2004 election. Our central message is that our federal leaders should learn from the past. Following the election of 1876, Congress was able, in time, to put aside partisan wrangling and constitutional concerns to enact presidential election reforms that have served our nation well for more than a century. The present Congress should take bold action as well. Invoking the powers we identify in this Article, our federal leaders should respond to th essentially technical and mechanical problems that cast a lingering cloud over the 2000 election. In short, Congress should address the visionary legislation the gravest problems that surfaced in the last election to ensure they do not reoccur in the future

Means/Ends Analysis in Copyright Law: Eldred v. Ashcroft in One Act

Scene: The quiet hallway of a law school. A troubled young professor of Intellectual Property law stands in front of a senior colleague\u27s office and studies a pencil sketch of Bushrod Washington taped to the door. After a moment\u27s hesitation, he knocks and enters