Around Kolmogorov complexity: basic notions and results

Algorithmic information theory studies description complexity and randomness and is now a well known field of theoretical computer science and mathematical logic. There are several textbooks and monographs devoted to this theory where one can find the detailed exposition of many difficult results as well as historical references. However, it seems that a short survey of its basic notions and main results relating these notions to each other, is missing. This report attempts to fill this gap and covers the basic notions of algorithmic information theory: Kolmogorov complexity (plain, conditional, prefix), Solomonoff universal a priori probability, notions of randomness (Martin-L\"of randomness, Mises--Church randomness), effective Hausdorff dimension. We prove their basic properties (symmetry of information, connection between a priori probability and prefix complexity, criterion of randomness in terms of complexity, complexity characterization for effective dimension) and show some applications (incompressibility method in computational complexity theory, incompleteness theorems). It is based on the lecture notes of a course at Uppsala University given by the author

The Parameterized Complexity of Domination-type Problems and Application to Linear Codes

We study the parameterized complexity of domination-type problems. (sigma,rho)-domination is a general and unifying framework introduced by Telle: a set D of vertices of a graph G is (sigma,rho)-dominating if for any v in D, |N(v)\cap D| in sigma and for any $v\notin D, |N(v)\cap D| in rho. We mainly show that for any sigma and rho the problem of (sigma,rho)-domination is W[2] when parameterized by the size of the dominating set. This general statement is optimal in the sense that several particular instances of (sigma,rho)-domination are W[2]-complete (e.g. Dominating Set). We also prove that (sigma,rho)-domination is W[2] for the dual parameterization, i.e. when parameterized by the size of the dominated set. We extend this result to a class of domination-type problems which do not fall into the (sigma,rho)-domination framework, including Connected Dominating Set. We also consider problems of coding theory which are related to domination-type problems with parity constraints. In particular, we prove that the problem of the minimal distance of a linear code over Fq is W[2] for both standard and dual parameterizations, and W[1]-hard for the dual parameterization. To prove W[2]-membership of the domination-type problems we extend the Turing-way to parameterized complexity by introducing a new kind of non deterministic Turing machine with the ability to perform `blind' transitions, i.e. transitions which do not depend on the content of the tapes. We prove that the corresponding problem Short Blind Multi-Tape Non-Deterministic Turing Machine is W[2]-complete. We believe that this new machine can be used to prove W[2]-membership of other problems, not necessarily related to dominationComment: 19 pages, 2 figure

Zero-Gravity Vortex Vent and PVT Gaging System

Space Station and satellite reservicing will require the ability to vent gas on orbit from liquid supply or storage tanks and to gage liquid quantity under microgravity conditions. In zero gravity, (zero-g) the vortex vent is capable of venting gas from a tank of liquid containing gas randomly distributed as bubbles. The concept uses a spinning impeller to create centrifugal force inside a vortex tube within a tank. This creates a gas pocket and forces the liquid through a venturi and back into the tank. Gas is then vented from the gas pocket through a liquid detector and then out through an exhaust port. If the liquid detector senses liquid in the vent line, the fluid is directed to the low-pressure port on the venturi and is returned to the tank. The advantages of this system is that it has no rotating seals and is compatible with most corrosive and cryogenic fluids. A prototype was designed and built at the NASA Johnson Space Center and flown on the KC-135 zero-g aircraft. During these test flights, where microgravity conditions are obtained for up to 30 sec, the prototype demonstrated that less than 0.10 percent of the volume of fluid vented was liquid when the tank was half full of liquid. The pressure volume temperature (PVT) gaging system is used in conjunction with the vortex vent to calculate the amount of liquid remaining in a tank under microgravity conditions. The PVT gaging system is used in conjunction with the vortex vent to gage liquid quantity in zero or low gravity. The system consists of a gas compressor, accumulator, and temperature and pressure instrumentation. To measure the liquid in a tank a small amount of gas is vented from the tank to the compressor and compressed into the accumulator. Pressure and temperature in the tank and accumulator are measured before and after the gas transfer occurs. Knowing the total volume of the tank, the volume of the accumulator, the volume of the intermediate lines, and initial and final pressures and temperatures, the mass of the gas leaving the tank is equated to the mass of the gas entering the accumulator. The volume of liquid remaining in the tank is calculated using the ideal gas law

Computer aided design and manufacturing of composite propfan blades for a cruise missile wind tunnel model

One of the propulsion concepts being investigated for future cruise missiles is advanced unducted propfans. To support the evaluation of this technology applied to the cruise missile, a joint DOD and NASA test project was conducted to design and then test the characteristics of the propfans on a 0.55-scale, cruise missile model in a NASA wind tunnel. The configuration selected for study is a counterrotating rearward swept propfan. The forward blade row, having six blades, rotates in a counterclockwise direction, and the aft blade row, having six blades, rotates in a clockwise direction, as viewed from aft of the test model. Figures show the overall cruise missile and propfan blade configurations. The objective of this test was to evaluate propfan performance and suitability as a viable propulsion option for next generation of cruise missiles. This paper details the concurrent computer aided design, engineering, and manufacturing of the carbon fiber/epoxy propfan blades as the NASA Lewis Research Center

An evaluation of a program of teaching independent writing in grade III

Thesis (Ed.D.)--Boston Universit

So You Think You Can Dance: The Phenomenon of Library Flash Raves

Libraries have long been held to a certain stereotype, as being sedate and formal locales meant for tranquil study and quiet reflection. In popular culture this stereotype has been reinforced when that quiet scene is disrupted by song and dance; movies such as The Music Man and The Breakfast Club, television shows like Glee and music videos depict patrons and even staffers frolicking in the stacks and dancing on the desks. More recently the phenomenon of “flash mobs” and their sister flash raves have reflected the movie musical archetype of bursting into song in an otherwise ordinary setting. The flash rave has reached the hallowed halls of academia, primarily promoted as a stress reliever during final exam periods. While some have been true “flash” mobs, with students descending unannounced upon campus libraries and learning commons, others have been welcomed and even sanctioned by library administrations. Flash mobs and modern libraries also happen to share a common thread; the adoption of social media tools to organize, collaborate and share information. This paper will examine the depiction of dancing in the library, the evolution of the library flash rave, and how libraries are utilizing these raves and their social networking origins as tools for promotion of library services, student outreach and campus recruitment

Death with Dignity: The Legislative Wave of the Future

The objective of this paper is to determine whether the United States will experience a significant increase in the passage of Death with Dignity legislation. The methods used to predict future legislation was a comparative examination of the history of the legislation politically and socially within the United States. The historical trends of the legislation were compared with global trends as well as current societal factors that may influence legislation. The results will indicate that societal factors such as global influence, social media and the Baby Boom generation will have a dramatic affect in the rapid increase in Death with Dignity legislation soon to come. The paper will conclude that due to the historical trends of the legislation and the current societal factors involved in the issue; the Supreme Court should expand the original ruling allowing the option of Death with Dignity to be available in all 50 states

Revisiting Bucket Truck: Locally Engaged Public Intellectuals

In this essay, the author argues that given current shifts in the axiological imperatives which inform research, local manifestations of the global political trend toward post-truth populism, and the saturation of the university in settler colonial, patriarchal, hegemonic ideology, there is a dire need for an alternative model of scholarly engagement—what the author calls locally engaged public intellectuals. Through the lyrics of Canadian rock band Bucket Truck, the author gestures toward the way local critiques can contextualize local issues and disrupt the post-truth narrativizing which often paints Indigenous and other marginalized groups as dissidents. Bucket Truck, the author argues, were an example of such locally engaged public intellectuals. The group thus deserves our consideration not just as a now defunct Canadian rock band, but as an example of local critique made accessible to affected communities