Beyond UNIX - A True Distributed System for the 1990s

UNIX has been around now for almost 20 years. At the time UNIX began, most departments felt themselves well-endowed indeed if they owned a single PDP-11/45 with 256K memory and a 2.5M RK05 disk. Nowadays a laptop would be embarrassed to have only that. It is our hypothesis that UNIX is no longer the appropriate kind of operating system for the 1990s. In this paper, a new system, Amoeba, will be described, that we believe meets the requirements for distributed computing in the 1990s

Studies Of A Quantum Scheduling Algorithm And On Quantum Error Correction

Quantum computation has been a rich field of study for decades because it promises possible spectacular advances, some of which may run counter to our classically rooted intuitions. At the same time, quantum computation is still in its infancy in both theoretical and practical areas. Efficient quantum algorithms are very limited in number and scope; no real breakthrough has yet been achieved in physical implementations. Grover\u27s search algorithm can be applied to a wide range of problems; even problems not generally regarded as searching problems can be reformulated to take advantage of quantum parallelism and entanglement leading to algorithms which show a square root speedup over their classical counterparts. This dissertation discusses a systematic way to formulate such problems and gives as an example a quantum scheduling algorithm for an R||C_max problem. This thesis shows that quantum solution to such problems is not only feasible but in some cases advantageous. The complexity of the error correction circuitry forces us to design quantum error correction codes capable of correcting only a single error per error correction cycle. Yet, time-correlated errors are common for physical implementations of quantum systems; an error corrected during a certain cycle may reoccur in a later cycle due to physical processes specific to each physical implementation of the qubits. This dissertation discusses quantum error correction for a restricted class of time-correlated errors in a spin-boson model. The algorithm proposed allows the correction of two errors per error correction cycle, provided that one of them is time-correlated. The algorithm can be applied to any stabilizer code, perfect or non-perfect, and simplified the circuit complexity significantly comparing to the classic quantum error correction codes

Repair As Research: How Copyright Impedes Learning About Devices

Widespread computerization and ubiquitous smart devices have enabled software-based copyright governance to reach into new domains. Beyond their instrumental utility, these devices are also containers of vast amounts of information in the form of software and technical know-how. Through copyright and anti-circumvention rules, however, this information can be cordoned off and confined to exclusive distribution channels. This can have a significant impact on research. While copyright law traditionally conceives research as the use of expressive works within institutional settings, this paper proposes a broader conceptualization that includes device research, including informal inquiries and DIY activities. Whether for the purposes of modification, repair, user innovation, or testing, device research involves the analytical engagement with physical devices. With a particular focus on repair-related activities as a modality of device research, this paper refers to product teardowns, reverse engineering, security research, and testing analyses. It then looks to case studies that exemplify the ways in which copyright can impede this type of research. In highlighting the conceptual overlap between the Right to Repair and Right to Research movements, the authors propose that a broader concept of research in copyright that includes device research could normatively reinforce and bolster support for a Right to Research in international copyright law