Unbounded Recursion and Non-size-increasing Functions

We investigate the computing power of function algebras defined by means of unbounded recursion on notation. We introduce two function algebras which contain respectively the regressive logspace computable functions and the non-size-increasing logspace computable functions. However, such algebras are unlikely to be contained in the set of logspace computable functions because this is equivalent to L=P . Finally, we introduce a function algebra based on simultaneous recursion on notation for the non-size-increasing functions computable in polynomial time and linear space

Jakob Leupold’s Imaginary Automatic Anamorphic Devices of 1713

In 1713 the scientific instrument-maker Jakob Leupold published designs for three machines were the first attempt to design machinery with internal moving parts that replaced human agency in creating original images. This paper first analyzes his text and engravings in order to explain how he proposed to do this, given contemporary materials and command of physical forces. Next, it characterizes the devices as a transition from concepts of incision to concepts of mirroring, taken as models of the history of mechanical reproduction. And finally, Leupold’s replacement of the sighting grid with differential gears points to a set of problems appearing in contemporary philosophy represented in Rococo artistic production of this period as well. Taking the proposed devices in context, they help to theorize the complex notions of creative activity in Rococo visual culture. Taken as an episode in the history of communications, they instance the development of conceptions of personhood and of physical forces at stake in the invention of automated media

Conceptual Computing and Digital Writing

In 1952 computer scientist Christopher Strachey wrote a parodical love letter generator. This system, the prototype of all computational conceptual writing – the almost completely secret prototype – was up and running not only before conceptual writing was formulated but even before conceptual art had arrived. The program predates the earliest work that is consistently identified as part of the (yet unnamed) conceptual art movement, Rauschenberg’s Erased De Kooning Drawing. It was not created by someone who identified or was identified as a writer, or as an artist, and it seems to have been seen as more the server-room equivalent of a parlor game than as a part of the tradition of literary arts. Only recently have programmers and scholars provided versions of the generator that appear in an installation and Web contexts and discussed in depth the literary aspects of the system. All of this makes Strachey’s program not only the first in its category but also quite typical of the scattered, marginal, often overlooked projects that have explored the computer’s ability to write conceptually over the last sixty years

(In-)Approximability Results for Interval, Resource Restricted, and Low Rank Scheduling

We consider variants of the restricted assignment problem where a set of jobs has to be assigned to a set of machines, for each job a size and a set of eligible machines is given, and the jobs may only be assigned to eligible machines with the goal of makespan minimization. For the variant with interval restrictions, where the machines can be arranged on a path such that each job is eligible on a subpath, we present the first better than 2-approximation and an improved inapproximability result. In particular, we give a (2-1/24)-approximation and show that no better than 9/8-approximation is possible, unless P=NP. Furthermore, we consider restricted assignment with R resource restrictions and rank D unrelated scheduling. In the former problem, a machine may process a job if it can meet its resource requirements regarding R (renewable) resources. In the latter, the size of a job is dependent on the machine it is assigned to and the corresponding processing time matrix has rank at most D. The problem with interval restrictions includes the 1 resource variant, is encompassed by the 2 resource variant, and regarding approximation the R resource variant is essentially a special case of the rank R+1 problem. We show that no better than 3/2, 8/7, and 3/2-approximation is possible (unless P=NP) for the 3 resource, 2 resource, and rank 3 variant, respectively. Both the approximation result for the interval case and the inapproximability result for the rank 3 variant are solutions to open challenges stated in previous works. Lastly, we also consider the reverse objective, that is, maximizing the minimal load any machine receives, and achieve similar results

Observing productivity: what it might mean to be productive when viewed through the lens of Complexity Theory

The paper tries to explore options and preconditions for a theoretically thoroughly grounded conception of productivity that is able to account for its observer-dependency and thereby meets the needs of a dynamic and highly differentiated modern society. It does so in respect to insights from cybernetics and complexity theory, thereby taking up charges about the contradiction of economic productivity and the second law of Thermodynamics. In respect to epistemological consequences of contemporary levels of productivity, a seemingly paradoxical constraint is put forward: the constraint that productivity is conditioned on being observed as such, with the observer in its turn being conditioned on productivity. The assumption is that this paradoxical constitution helps to keep productivity adaptive to the changes it itself incites in economy

The Science Behind Breath Testing for Ethanol

Nationwide, law enforcement officers utilize breath-test machines to identify suspected drunk drivers. When defense attorneys represent a client who has been charged with alcohol related driving crimes, it is important to understand the science and methodology behind alcohol breath-testing, and specifically the functionality of the device used to test their client. This article explains the various methods of testing and types of devices used, as well as their effectiveness, by examining the scientific principles associated with common testin measures. This article serves as an aid to the practicing attorney who, by understanding the science and methodology of breath-testing, will be better situated to assist defendants facing breath-test evidence