text stringlengths 59 1.12k |
|---|
Printer friendly version Lightweight True Random Number Generators A Step Closer 17 September 2010 Queen's University, Belfast The widespread use of true random number generators (TRNGs) has taken a step |
closer following the creation of the most lightweight designs to date by researchers at Queen’s University Belfast’s Institute of Electronics, Communications and Information Technology (ECIT). Members of the Institute’s cryptography |
research team have produced a series of circuits that are up to 50 per cent smaller than anything else currently available. Optimised for digital circuits, FPGA and ASIC, they push |
efficiency to the limit by using just one logic gate, one look-up table and four transistors respectively. TRNGs are essential for IT security because virtually any security application relies on |
unpredictable numbers such as cryptographic keys. Current systems however are either too expensive or are not fast enough for many applications. That is why more nimble pseudo-random number generators are |
in widespread use even though the sequences they generate can be detected under certain types of attack, making them much less secure. The approach of ECIT researchers Jiang Wu and |
Dr Máire O’Neill has been to use the white noise inside the circuit to generate the randomness, effectively simulating the toss of a coin. To do this, they developed a |
new mechanism to measure the noise and generate the random output. “The most challenging part of the work was to find the new mechanism that can effectively sample the noise,” |
said Wu. “True random number generators have been extensively studied in recent years; many very efficient designs based on different noise measurement mechanisms have been proposed. It was not clear |
if more efficient designs were even possible. After investigating several candidates, finally we found a successful one.” The next step is to find ways of making the generators sufficiently robust |
to be embedded in devices such as mobile phones, smartcards and RFID tags, and – where they are used for security applications - to secure them from attack and develop |
appropriate countermeasures. Other related work currently underway at ECIT includes designs for highly efficient physical unclonable functions (PUFs). These authenticate individual chips by extracting and identifying – but without revealing |
Population Guide: Dairy How Many Is Too Many? An effective control program keeps horn fly levels to fewer than 50 per animal. This at-a-glance-guide will help you easily evaluate the effect that horn flies currently have on your herd. Keep these other assessment tips in mind, too. - The horn |
fly is charcoal gray and approximately five millimeters long (half the size of a typical house fly). - Adult horn flies are located on the backs of cattle, often clustering on the midline and spreading down the sides. Sometimes, they settle around the base of cattle horns. When the weather |
is hot, they may move onto the animals' undersides. - It's easiest to make the most accurate estimate in the morning, when horn flies are on the upper sides of the cows. |Average to Below||Unacceptable| |
by Jos Van der Poel Down’s syndrome is a genetic disorder (in stead of two these persons have three chromosomes 21) that besides a number of physical characteristics leads to intellectual impairment. It occurs in one out of every 1.000 births. Life expectancy of people with Down’s syndrome has increased |
substantially over the last century: about 50 % of them will reach the age of 60. Because of the trisomie 21 people with Down’s syndrome have an overexpression of the amyloid precursor protein. Amyloid is the main ingredient of the plaques, which are found in the brains of people with |
Alzheimer’s disease. Symptoms and course Not all persons with Down’s syndrome show evidence of cognitive deterioration or other clinical evidence of dementia even after extended periods of observation. Clinical symptoms at first are increasing depression, indifference and a decline in social communication. Later sympto... |
changes in personality, loss of memory and general functions, long periods of inactivity or apathy, hyperactive reflexes, loss of activity of daily skills, visual retention deficits, loss of speech, disorientation, increase in stereotyped behaviour and abnormal neurological signs. Especially for brothers and sisters wh... |
(the care of) their sibling with Down’s syndrome when their parents have died. It is distressing when this person develops Alzheimer’s disease at a relatively young age. Not only are they loosing the person they (often) love very much, but the burden of care gets heavier. Causes and risk factors |
In Down’s syndrome the development of Alzheimer’s disease seems to be linked directly to the overexposure to APP. The ApoE2 gene seems to have a protective effect in Down’s syndrome too, but whether ApoE4 increases the risk of Alzheimer’s disease in Down’s syndrome is not clear yet. Men and women |
96 % of all adults with Down’s syndrome. Diagnosing dementia in people with Down’s syndrome is very difficult, as the dementia symptoms are often masked by the existing intellectual impairment. Several screening and evaluation procedures have been developed. These evaluations must be performed at select intervals, thus... |
person’s previous score. Definitive diagnosis is only available after death. Care and treatment Because of limited personel in small scale living settings for people with an intellectual impairment, persons with dementia often have to move (back) to an institution for mentally retarded people. Research has shown that d... |
a positive though not significant effect. Ongoing research/Clinical trials Erasmus University Rotterdam (Evenhuis HM) - Beer EFG de; De effecten van donepezil bij Downsyndroom; Down + Up 2003; 62 - Lott IT, Head E; Down syndrome and Alzheimer’s disease: a link between development and aging; Ment Ret Dev Dis 2001; |
7 - Visser FE; Down en Alzheimer in perspectief; dissertation 1996 - Down’s Syndrome and Alzheimer’s Disease; Briefing North West Training & Development Team (1995) - Dementia an Intellectual Disabilities; Fact sheet Alzheimer’s Disease International (s.a.) Last Updated: vendredi 09 octobre 2009 |
In 1621, the Plymouth colonists and Wampanoag Indians shared an autumn harvest feast that is acknowledged today as one of the first Thanksgiving celebrations in the colonies. For more than |
two centuries, days of thanksgiving were celebrated by individual colonies and states. It wasn't until October 1777 that all 13 colonies celebrated day of Thanksgiving. The very first national day |
of Thanksgiving was held in 1789, when President George Washington proclaimed Thursday, Nov. 26, to be "a day of public thanksgiving and prayer to be observed by acknowledging with grateful |
hearts the many signal favors of Almighty God especially by affording them an opportunity peaceably to establish a form of government for their safety and happiness." Though a national day |
of Thanksgiving was declared in 1789, Thanksgiving was not an annual celebration. We owe the modern concept of Thanksgiving to poet and editor, Sarah Josepha Hale. Hale wrote the famous |
nursery rhyme, "Mary Had a Little Lamb," and was editor of "Godey's Lady's Book." She spent 40 years advocating for a national, annual Thanksgiving holiday. In the years leading up |
to the Civil War, she saw the holiday as a way to infuse hope and belief in the nation and the constitution. So, when the United States was torn in |
half during the Civil War and President Abraham Lincoln was searching for a way to bring the nation together, he discussed the matter with Hale. On Oct. 3, 1863, Lincoln |
issued a Thanksgiving Proclamation that declared the last Thursday in November (based on Washington's date) to be a day of "thanksgiving and praise." For the first time, Thanksgiving became a |
national, annual holiday with a specific date. For 75 years after Lincoln issued his Thanksgiving Proclamation, succeeding presidents honored the tradition and annually issued their own Thanksgiving Proclamation, declaring the |
last Thursday in November as the day of Thanksgiving. However, in 1939, during the Great Depression, the date of Thanksgiving was scheduled to be Nov. 30. Retailers complained to President |
Franklin D. Roosevelt (FDR) that this only left 24 shopping days to Christmas and begged him to push Thanksgiving just one week earlier. It was determined that most people do |
their Christmas shopping after Thanksgiving and retailers hope that with an extra week of shopping, people would buy more. When FDR announced his Thanksgiving Proclamation in 1939, he declared the |
date of Thanksgiving to be Thursday, Nov. 23, the second-to-last Thursday of the month. The new date for Thanksgiving caused a lot of confusion. Calendars were now incorrect. Schools who |
had planned vacations and tests now had to reschedule. Thanksgiving had been a big day for football games, as it is today, so the game schedule had to be examined. |
Before 1939, governors followed the president in officially proclaiming the same day as Thanksgiving for their state. In 1939, many governors did not agree with FDR's decision to change the |
date and refused to follow him. The country became split on which Thanksgiving they should observe. Twenty-three states followed FDR's change. Twenty-three other states disagreed with FDR and kept the |
traditional date for Thanksgiving. Two states, Colorado and Texas, decided to honor both dates. This idea of two Thanksgiving days split some families because not everyone had the same day |
off work. Did it work? The answer was no. Businesses reported that the spending was approximately the same but the distribution of the shopping was changed. For those states who |
celebrated the earlier Thanksgiving date, the shopping was evenly distributed throughout the season. For those states that kept the traditional date, businesses experienced a bulk of shopping in the last |
week before Christmas. In 1940, FDR again announced Thanksgiving to be the second-to-last Thursday of the month. This time, 31 states followed him with the earlier date and 17 kept |
the traditional date. Confusion over two Thanksgivings continued. Lincoln established the Thanksgiving holiday to bring the country together, but the confusion over the date change was tearing it apart. On |
Identifying Hurdles to Renewable Electricity Transmission SOURCE: AP/Thanassis Stavrakis This article contains a correction. Download this report (pdf) The next administration will face an extensive list of simultaneous policy challenges, not least of which include an international financial crisis, two wars abroad, an... |
economic recovery must be investing in a clean energy economy in order to create jobs and spur economic growth and prosperity, while at the same time fighting global warming and addressing national security. This report seeks to highlight the multiple challenges and opportunities for action to vastly increase our natio... |
transmission construction. Identifying the significant, but by no means insurmountable, obstacles to implementing this vision is the first step toward designing policy solutions that enable investments to not only significantly reduce our nation’s global warming emissions but also to put us on a path to a clean energy ... |
low-carbon economy. The current grid configuration cannot handle the growth in electricity demand expected over the next few decades unless we act quickly to modernize it. Grid modernization must be compatible with scaling up renewable energy generation, including the ability to incorporate intermittent renewable elect... |
efforts also include grid expansion, improved connectivity between different U.S. regions, increased efficiency of electricity transmission, improved security to ensure reliable supply of electricity, and adoption of smart grid technologies. The electricity grid in the United States is often heralded as one of the worl... |
now represents a central piece of economic and societal infrastructure. But nearly a century after grid construction began, no major updates have occurred. In a recent publication, the Department of Energy frames the issue well: If Alexander Bell were to see his original invention—the telephone—today, he would be blown... |
distribution and technologies since Thomas Edison’s time. Currently, the United States derives only 2 to 3 percent of its electricity from renewable sources, excluding hydropower. A national Renewable Portfolio Standard, or RPS—which sets a target percentage of renewable energy generation by a certain year—would dramat... |
President-elect Obama has endorsed a national RPS of 10 percent by 2012 and 25 percent by 2025. In the absence of federal leadership, 27 states and the District of Columbia have established state-level RPS requirements, and six additional states have explicit renewable electricity goals. Thus, about 70 percent of the U... |
set by any type of renewable portfolio standard requires grid modernization and new transmission, yet how to proceed is a contentious and difficult policy challenge. A timely example is unfolding in Minnesota, where Xcel Energy and other regional utilities are working on a project called CapX 2020 to add more than 700 ... |
The project is encountering a variety of obstacles, which reveal the difficulty that scaling up renewable electricity production is likely to face. Implementation hurdles to CapX 2020 and other projects include environmental, public, and political concerns, siting authority, permit approval procedures, and environmenta... |
workforce, grid access, and cost recovery for new construction. Even though new construction of renewable energy facilities and transmission lines offers significant environmental benefits—including reducing greenhouse gas emissions—any new construction risks facing public opposition for aesthetic, economic, or environ... |
public opposition is the offshore wind farm called Cape Wind in Cape Cod, Massachusetts, in the Nantucket Sound. The project was first proposed in 2001 and its developer spent years fighting public claims that the farm would be a visual sore, negatively affect tourism to the region, and threaten birds, bottom-dwelling ... |
not-in-my-backyard syndrome, or NIMBY, which describes a common tendency for people to favor a project until it directly affects them. Six years after Cape Wind was proposed, in January 2008, the U.S. Minerals Management Service completed an environmental impact statement and approved the wind farm, concluding it would... |
both integrate the public’s concern and expedite such decision-making processes. The opportunities to modernize the grid and the added urgency to combat global warming highlight the need to act quickly. Involving constituents early in the decision-making process can help temper public opposition to renewable energy inf... |
economic growth opportunities associated with clean energy infrastructure can generate greater support for these projects, too. One successful case study is the western United States. Both the Western Governors’ Association and individual states like Colorado have aggressively pursued initiatives to expand renewable en... |
of clean and renewable energy, and last year Colorado passed legislation (SB 100) requiring utilities to identify renewable energy resources and plan transmission lines to harness those resources. To accomplish these projects, WGA and Colorado have embarked on thorough stakeholder processes to ensure that invested voic... |
necessary renewable energy transmission infrastructure. In contrast, Pennsylvania and surrounding Mid-Atlantic states have seen opposition erupt over a transmission corridor designation, mainly due to the lack of sufficient consultation with the public and with state and local authorities. The Energy Policy Act of 2005... |
or congestion. The law also grants the Federal Energy Regulatory Commission backstop eminent domain authority to grant permits for interstate transmission lines if a transmission developer is not able to site a line at the state level after a year or under certain other conditions, and the line is in an NIETC. Eminent ... |
or local decisions on electricity transmission siting in the name of national interest, even when facing objections from states, localities, or private property owners. With this authority, the federal government has identified two NIETC corridors, one in the Southwest consisting of parts of Southern California and Wes... |
Delaware, and Maryland, and has also drawn significant opposition. In Pennsylvania, the NIETC encompasses 50 of the state’s 67 counties, and includes historic sites, agricultural land, protected habitats, and national parks. During the public comment period, over 2,000 replies were submitted expressing concern over the... |
be meaningless.” At least 14 senators representing Mid-Atlantic states are also opposed to the corridor. No fewer than three bills have been introduced in Congress to repeal or modify the federal government’s eminent domain authority in response to the Mid-Atlantic NIETC’s designation. These examples shed light on a hu... |
projects and authority over siting decisions. Navigating this question is proving to be politically contentious and time-consuming. Another pending conflict is in the Southwest, where Southern California Edison has launched a pre-filing consultation process with FERC in an effort to build a new transmission line betwee... |
much to be done to facilitate work between federal and state authorities to determine new transmission corridors. This is especially important in light of the increasing demand for new transmission to meet new electricity demand, stabilize the grid, and facilitate connecting renewable electricity to the grid. Permit Ap... |
are inconsistent across municipalities, counties, states, and the federal government. Efforts must be ramped up to develop an integrated strategy for working across jurisdictions and federal agencies to ensure swift and comprehensive review and permitting. A wind farm proposal, for example, could fall to any one of eig... |
and between state and federal government will be critical in order to reach ambitious goals for renewable energy penetration in our electrical supply. In the three years since the Energy Policy Act of 2005 encouraged renewable energy development on federal land, the Bureau of Land Management has yet to approve a single... |
the BLM attempted to entirely freeze solar applications on BLM-managed land until it could sort out its environmental assessment. However, the agency’s attempted moratorium was met with fervent protest and the decision was reversed within months. Another example occured in October 2008, when the Department of Interior ... |
however, the Environmental Protection Agency has raised concerns about groundwater and air quality impacts regarding the PEIS. The Energy Policy Act of 2005 requires coordinated effort by the secretaries of agriculture, commerce, defense, energy, and interior, in consultation with FERC, other governments, industries, a... |
facilities on federal lands, in part in an to attempt to reduce federal siting hurdles experienced by energy developers. Recently, the federal government designated the West-wide energy corridor, which stretches across 11 states and covers nearly 3 million acres. Western states that the corridor affects have made recen... |
Project. The West-wide designation has met with public opposition because of claims it should have given greater prioritization to renewable electricity, and that the involved federal agencies did not adequately consult regional or local entities before creating the energy corridors on protected federal lands, such as ... |
it clear that there are many priorities to consider as we develop our nation’s energy resources. While difficult choices between conflicting priorities will continue to arise, there will also be opportunities to address these challenges as efforts to scale up renewable energy proceed. One of the goals of new renewable ... |
potential to regions of the country with the greatest demand is to advance the environmental goal of reducing our nation’s greenhouse gas emissions and to facilitate a shift to a low-carbon economy. The Center for American Progress has argued that federal permitting of new projects that require environmental impact sta... |
from those projects, but also the projected impacts of global warming on these projects to ensure responsible spending of taxpayer dollars. Thus, when weighed against high-carbon energy development projects, renewable projects should be accelerated given global warming considerations. Yet new construction and developme... |
water supply, water quality, and air quality. Decisions must be considered given regulation set by the Endangered Species Act and the Clean Water Act, among others. Recently the Environmental Protection Agency warned that the evaluation drafted by the Interior Department—the PEIS mentioned above—does not adequately con... |
there are 23 aquifers that people depend on for drinking water. Before moving forward on a large scale, the EPA argues we need a concrete understanding of if and how much water supply could be depleted (particularly in the West). Still, the environmental impact of renewable energy is estimated to be far less than that ... |
and land disturbance. Renewable electricity-generating technologies are estimated to use tens of billions of gallons less water than thermoelectric power plants. Coal mining is estimated to disrupt 400,000 hectares of U.S. land each year. In contrast, a Department of Energy scenario that sketches how to acquire 20 perc... |
one-time disruption of 100,000 to 250,000 hectares. That is, if they cannot be sited on previously disturbed lands, such as “brownfield” sites. California has expressed a preference for siting new renewable energy generation on brownfield sites because reusing the land reduces environmental degradation, and the Califor... |
question of cost recovery are additional challenges to address. Despite the political interest, enthusiasm, and necessity to revamp our energy and electricity infrastructure, we have not yet adequately invested in facilitating a ramped-up clean energy and transmission workforce, including engineers, manufacturers, and ... |
barrier causing a bottleneck in the future growth of the renewable energy and energy-efficiency industries. This growing skills shortage is occurring even as the American Public Power Association reports that half of current utility workers will retire within the next decade. Policymakers must work to remedy this short... |
national electricity grid that facilitates renewable energy access. Currently, we do not have one, large grid; we have three, separate regional grids called Interconnects—the Western Interconnect, the Eastern Interconnect, and the Texas Interconnect. The current capacity to transmit electricity across interconnects is ... |
between interconnects, a technical barrier to transporting electricity to where it could be most needed. Ensuring renewable energy access to transmission infrastructure—existing infrastructure as well as new transmission lines—is another imperative. Part of this challenge requires load integration between renewable and... |
in the process of learning the best techniques to integrate renewable energy, especially since it is often an intermittent source. Yet transmission lines are in high demand, and new transmission networks also need to be built out. As the example of the West-wide corridor illustrates, renewable energy still needs to eme... |
terms of accessing transmission capacity. Finally, utilities, developers, and policymakers have to decide how to distribute costs and create a plan to pay for renewable energy transmission infrastructure. Should electricity ratepayers who benefit see a slight increase in prices, or should a renewable energy-compatible ... |
may need innovation and a national approach to problem solving. Traditional strategies for rate recovery allocate the costs of new projects to those rate payers who benefit, but this regional allocation of costs may not be sufficient when the benefits of improved reliability and greater use of clean energy are benefits... |
is much larger than any single utility or service area. In these cases, there may be strong reasons for a federal commitment to take on the costs of upgrading our electrical infrastructure to provide a truly national clean energy network. Regardless of the ultimate resolution of this question, it is a near certainty th... |
Our economy is in trouble, and a massive investment in clean energy must be part of the solution. We are in need of major investments to rejuvenate communities, create new markets and growing industries, and create jobs rebuilding our infrastructure. At the same time we also need to take significant steps to reduce our... |
intersection of our national security interests and our energy and economic security as well, yet it can be a tremendous source of inspiration for America’s spirit of innovation, and a good way to invest in a more prosperous future. A clean energy economy is not only better for the environment, but it is also more mode... |
for American workers and their employers. As the Obama administration sets its priorities, it must take a close look at new renewable electricity generation and the advanced transmission that will be required to take wind, solar, and geothermal to a national scale. As the administration lays new plans for infrastructur... |
Every generation has to reinvent the practice of computer programming. In the 1950s the key innovations were programming languages such as Fortran and Lisp. The 1960s and '70s saw a crusade to root out "spaghetti code" and replace it with "structured programming." Since the 1980s software development has been dominated... |
OOP may be running out of oomph, and discontented programmers are once again casting about for the next big idea. It's time to look at what might await us in the post-OOP era (apart from an unfortunate acronym). The Tar Pit The architects of the earliest computer systems gave little thought to software. (The very word ... |
the machine itself was the serious intellectual challenge; converting mathematical formulas into program statements looked like a routine clerical task. The awful truth came out soon enough. Maurice V. Wilkes, who wrote what may have been the first working computer program, had his personal epiphany in 1949, when "the ... |
my life was going to be spent in finding errors in my own programs." Half a century later, we're still debugging. The very first programs were written in pure binary notation: Both data and instructions had to be encoded in long, featureless strings of 1s and 0s. Moreover, it was up to the programmer to keep track of w... |
machine's memory. Before you could call a subroutine, you had to calculate its address. The technology that lifted these burdens from the programmer was assembly language, in which raw binary codes were replaced by symbols such as load, store, add, sub. The symbols were translated into binary by a program called an ass... |
in which the computer was recruited to help with its own programming. Assembly language was a crucial early advance, but still the programmer had to keep in mind all the minutiae in the instruction set of a specific computer. Evaluating a short mathematical expression such as x2+y2 might require dozens of assembly-lang... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.