منابع مشابه
Can the Universe Create Itself?
The question of first-cause has troubled philosophers and cosmologists alike. Now that it is apparent that our universe began in a Big Bang explosion, the question of what happened before the Big Bang arises. Inflation seems like a very promising answer, but as Borde and Vilenkin have shown, the inflationary state preceding the Big Bang could not have been infinite in duration — it must have ha...
متن کاملClean air in Europe: beyond the horizon?
The current EU limit values for PM2.5 and PM10 are far too high http://ow.ly/E6HUR When the European Union (EU) set its first Air Quality Limit Values for particulate matter in outdoor air (particulate matter <10 μm in diameter (PM10)) back in 1999, it promised to set a much stricter limit by 2010 [1]. The goal at the time was for an annual limit value of 20 μg·m, equivalent to the World Health...
متن کاملPhytoremediation for Environmental Clean Up
Pollution is an undesirable change in the physical, chemical or biological characteristics of air, land and water that will waste or deteriorate our raw material resources. Modern technological innovations have increased pollution levels above the self cleaning capacities of the environment. In recent times, one of the major issues is the threat to human life from the progressive deterioration ...
متن کاملNon-Local Topological Clean-Up
A new approach to topological clean-up of 2D meshes is presented. Instead of searching for patterns in a mesh and replacing them as in other methods, the proposed method replaces a region in a mesh only according to the boundary of that region. This simplifies the classification of the different cases, and allows mesh modification over greater regions in the mesh. An algorithm for quadrilateral...
متن کاملCan a Program Reverse-Engineer Itself?
Shape-memory alloys are metal pieces that "remember" their original cold-forged shapes and return to the pre-deformed shape after heating. In this work we construct a software analogous of shape-memory alloys: programs whose code resists obfuscation. We show how to pour arbitrary functions into protective envelops that allow recovering the functions' exact initial code after obfuscation. We exp...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Nature
سال: 1976
ISSN: 0028-0836,1476-4687
DOI: 10.1038/259002a0