UNIX Version Research Articles

On the Origin of Kerberos

Reports on the special features and applications supported by Kerberos, a cryptographic authentication and key distribution system developed by MIT Project Athena with the goal that a single login provide access to many different computing services. Kerberos is distributed as a component of most major operating systems, including Microsoft Windows, Apple OS/X and IOS, IBM z/OS, and many versions of Unix.

Visualization of virtual environment through labVIEW platform

Abstract Virtual instrumentation is the use of customizable software and modular measurement hardware to create user-defined measurement systems, called virtual instruments. The primary difference between hardware instrumentation and virtual instrumentation is that LabVIEW software is used to replace a large amount of hardware. The software enables complex and expensive hardware to be replaced by already purchased computer hardware. Virtual Instrumentation is established using LabVIEW. Laboratory Virtual Instrument Engineering Workbench (LabVIEW) is a system-design platform and development environment for a visual programming language from National Instruments. The graphical language is named “G”; not to be confused with G-code. Originally released for the Apple Macintosh in 1986, LabVIEW is commonly used for data acquisition, instrument control, and industrial automation on a variety of Operating Systems (OSs), including Microsoft Windows, various versions of Unix, Linux, and MacOS. Simple timer Circuit, Traffic Light Control System, Automotive Safety assurance, Speed, Direction control of DC motor and Library Database File Management are realized by implementing VI programs. Select switch, Looping concepts, Case and Flat Sequence structures, String Manipulation, Clusters, File IO systems and Arduino interfacing through DAQ are used to implement all Simulation Models. Software Developed timer circuit and Automotive Safety assurance overcome the accuracy problem of conventional circuits. Designed Library Management system enhances ease of tracking. Conventional control of DC motor relies on hardware accessories such as Field and Armature rheostats and it requires manual implementation, whereas Virtual instrumentation makes software based control and it improves the system reliability. Fetching of Real time data and manipulation addresses the flexibility issue of hardware based Traffic Light Control system.

For Fun and Profit: A History of the Free and Open Source Software Revolution by Christopher J. Tozzi

Reviewed by: For Fun and Profit: A History of the Free and Open Source Software Revolution by Christopher J. Tozzi Mark Priestley (bio) For Fun and Profit: A History of the Free and Open Source Software Revolution. By Christopher J. Tozzi. Cambridge, MA: MIT Press, 2017. Pp. 336. Hardcover $30. The term "free and open source software" (FOSS) does not primarily refer to software written for a specific application or to a particular approach to software production, but rather to the manner of its distribution. Typically, FOSS can be used, modified, and redistributed without the hindrance of, or payment to, its original authors. "Free" signifies liberty as well as the absence of cost, and "open source" means that the secrets of the software's code are exposed. [End Page 655] There has always been free software. Electronic computers were originally sold without software and users collaborated to exchange information and code, as the name of the 1950s IBM user group SHARE suggests. Software soon became commercialized, of course, but traditions of openness persisted, notably in universities. In the 1980s, largely due to the activities of MIT programmer Richard Stallman, a discourse of "free software" emerged in opposition to the perceived commercialization of hitherto widely available code, in particular the Unix operating system developed at Bell Labs. By the turn of the millennium, FOSS developers had created the GNU/Linux operating system and several other significant products. FOSS is now a crucial part of the networked world, providing both software—for example web servers, desktop environments, and the FOSS-derived Android operating system that powers the majority of the world's mobile phones—and many of the programming languages in which that software is written. Tozzi describes this transformation as a "revolution" and uses this metaphor to structure his book. However, he does not mention Thomas Kuhn's 1962 classic The Structure of Scientific Revolutions or the voluminous literature inspired by it. Instead, the book uses a high-level schema derived from reflection on historical revolutions to structure the story of FOSS. For example, a chapter entitled "the Moderate FOSS Revolution" is associated with Louis XVI's acceptance of a constitutional monarchy in France in 1789 and the period between the March and October 1917 revolutions in Russia, with Tozzi commenting that "it is generally during the moderate stage that the most productive and enduring revolutionary changes arise" (p. 163). The use of this structuring device seems rather artificial and does not add much insight to the story of FOSS. Tozzi begins his story with Unix, a system he describes as embodying much of the ethos of "hacker culture". He draws on Stephen Levy's book Hackers: Heroes of the Computer Revolution (Doubleday, 1984) to flesh out this rather vague notion, and in many ways Tozzi's book reads as an extension of Levy's narrative to the history of FOSS. A "crisis" in this culture (the word is not used in Kuhn's sense) caused by the attempted commercialization of Unix led uber-hacker Stallman to propose the term "free software" and to start an attempt to create a "free" version of Unix. In one crucial respect (the production of the so-called "kernel" of the system) this effort stalled, and only the efforts of a project initiated in 1991 by Finnish student Linus Torvalds enabled the production of a complete operating system, usually simply called Linux. The heroic exploits of Stallman and Torvalds are recounted in a chapter each and the book then follows the revolutionary script by describing, after the stage of moderate revolution, a period of "revolutionary war" characterized by infighting between proponents of different ideological approaches to FOSS and also between FOSS advocates and Microsoft. A final chapter surveys the successes of FOSS in the years since 2000. [End Page 656] Tozzi provides a lively and entertaining account of these developments, but much of the story is available in popular and journalistic accounts, and readers may be left feeling that an opportunity to dig deeper has been missed. Anxious to prevent the commercial capture of free software, FOSS developers have proposed a bewildering variety of licenses under which it can be distributed, and while Tozzi describes...

A cost-effective multi-track introduction to Linux, Git and GitHub

Currently about 60% to 65% of servers on the internet run a version of Linux or Unix. Android, the world's most popular mobile operating system, is a Linux-based system; many devices run on the Lin...

Census-based rapid and accurate metagenome taxonomic profiling.

BackgroundUnderstanding the taxonomic composition of a sample, whether from patient, food or environment, is important to several types of studies including pathogen diagnostics, epidemiological studies, biodiversity analysis and food quality regulation. With the decreasing costs of sequencing, metagenomic data is quickly becoming the preferred typed of data for such analysis.ResultsRapidly defining the taxonomic composition (both taxonomic profile and relative frequency) in a metagenomic sequence dataset is challenging because the task of mapping millions of sequence reads from a metagenomic study to a non-redundant nucleotide database such as the NCBI non-redundant nucleotide database (nt) is a computationally intensive task. We have developed a robust subsampling-based algorithm implemented in a tool called CensuScope meant to take a ‘sneak peak’ into the population distribution and estimate taxonomic composition as if a census was taken of the metagenomic landscape. CensuScope is a rapid and accurate metagenome taxonomic profiling tool that randomly extracts a small number of reads (based on user input) and maps them to NCBI’s nt database. This process is repeated multiple times to ascertain the taxonomic composition that is found in majority of the iterations, thereby providing a robust estimate of the population and measures of the accuracy for the results.ConclusionCensuScope can be run on a laptop or on a high-performance computer. Based on our analysis we are able to provide some recommendations in terms of the number of sequence reads to analyze and the number of iterations to use. For example, to quantify taxonomic groups present in the sample at a level of 1% or higher a subsampling size of 250 random reads with 50 iterations yields a statistical power of >99%. Windows and UNIX versions of CensuScope are available for download at https://hive.biochemistry.gwu.edu/dna.cgi?cmd=censuscope. CensuScope is also available through the High-performance Integrated Virtual Environment (HIVE) and can be used in conjunction with other HIVE analysis and visualization tools.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2164-15-918) contains supplementary material, which is available to authorized users.

Upper Gastrointestinal Bleeding in Elderly Adults with Dementia Receiving Cholinesterase Inhibitors: A Population‐Based Cohort Study

Upper Gastrointestinal Bleeding in Elderly Adults with Dementia Receiving Cholinesterase Inhibitors: A Population‐Based Cohort Study

Understanding Operating Systems

Now in its Sixth Edition, UNDERSTANDING OPERATING SYSTEMS continues to provide a clear and straightforward explanation of operating theory and practice. As in previous editions, the book's highly-regarded structure begins with a discussion of fundamentals before moving on to specific operating systems. This edition has been updated and modernized; now included are enhanced discussions of the latest innovation evolutions (multi-core processing, wireless technologies, PDA and telephone operating systems, and Blu-ray optical storage) and how they affect operating systems. Revised Research Topics in the exercise section encourage independent research among students. Content in the final four chapters has been updated to include information about a few of the latest versions of UNIX (including specific mention of the latest Macintosh OS), Linux, and Windows.

Starburst99 for Windows

We present a Windows compatible version of the evolutionary synthesis code Starburst99. Starburst99 for Windows was developed from the public UNIX-based version at STScI. We converted the original Fortran77 source code into a version for a Win32 environment with an Absoft2Absoft® Corporation, 2781 Bond Street, Rochester Hills, MI 48309.2 Fortran Pro x86 compiler. Extensive testing showed no significant numerical differences in comparison with the previous UNIX version. The software application consists of the source code, executable, and a number of auxiliary files. The package installs on any PC running Windows 2000, XP, or Vista and can be obtained as freeware at http://www.stsci.edu/science/starburst/PCStarburst99.html. We give an overview of the different running modes and provide instructions for getting started with the initial set-up.

Fixing Apples' Broken Clipboard, with Java.

The Mac OS X clipboard is infamous for changing the format of bit-mapped images that are pasted to it. These images are typically encoded using a QuickTime Tiff compressor that renders them unreadable on other platforms (e.g. Windows and Linux). This means that Mac users who create screen-shot based Word or PowerPoint documents are not able to view the images in those documents on nonMac platforms. QuickTime is available only under license. As a result, it is not generally available under any of the major open-source versions of UNIX (ironic, considering MacOS X is a kind of Unix). Further, windows’ users (even the ones that have QuickTime) cannot decode these images (installing QuickTime is no help). As a result, the QuickTime images in documents are unreadable. This article describes a work-around for the problem, using Java. The code has been tested and shown to work on a variety of platforms (even running under emulation using QEMU and Linux) [QEMU]. The program is distributed as a webstart application in the JAddressBook project.

Forensic artefacts left by Pidgin Messenger 2.0

Pidgin, formerly known as Gaim, is a multi-protocol instant messaging (IM) client that supports communication on most of the popular IM networks. Pidgin is chiefly popular under Linux, and is available for Windows, BSD and other UNIX versions. This article presents a number of traces that are left behind after the use of Pidgin on Linux, enabling digital investigators to search for and interpret instant messaging activities, including online conversations and file transfers. Specifically, the contents and structures of user settings, log files, contact files and the swap partition are discussed. In addition looking for such information in active files on a computer, forensic examiners can recover deleted items by searching a hard drive for file signatures and known file structures detailed in this article.

Assessment of S/R5/MOD3.3 Models of Stratified Molten Pool and Debris-to-Vessel Contact Resistance by TMI-2 Lower-Head Creep Rupture Analyses

The U.S. Nuclear Regulatory Commission (NRC) is consolidating all its severe-accident codes into one code, MELCOR, and making an effort to bring it into a state of parity with SCDAP/RELAP5/MOD3.3 (S/R5/M3.3) to model a Three Mile Island Unit 2 (TMI-2)–like accident. In this regard, this cooperative research project seeks to help the NRC to assess S/R5/M3.3 associated with case studies of the TMI-2 lower-head creep rupture. The results of the simulations clearly demonstrate that the TMI-2 lower-head failure occurs. Thus, solely using the S/R5/M3.3 models of the molten pool and debris-to-vessel contact resistance, without implementing the gap cooling model, cannot explain the conservation of the TMI-2 lower head during the accident. These studies also conclude that the results calculated with the UNIX and Microsoft PC versions of S/R5/M3.3 are comparable, and hydrogen productions as well as lower-head creep ruptures vary with different time steps for the alternative accident. Further, those results for the base case and alternative accident are alike; thus, the models cannot differentiate between the base-case and alternative accident scenarios.

Options for putting CDS/ISIS databases on the internet

PurposeTo review the variety of software solutions available for putting CDS/ISIS databases on the internet. To help anyone considering which route to take.Design/methodology/approachBriefly describes the characteristics, history, origin and availability of each package. Identifies the type of skills required to implement the package and the kind of application it is suited to. Covers CDS/ISIS Unix version, JavaISIS, IsisWWW, WWWISIS Versions 3 and 5, Genisis, IAH, WWW‐ISIS, and OpenIsis.FindingsThere is no obvious single “best” solution. Several are free but may require more investment in acquiring the skills to install and configure them. The choice will depend on the user's experience with CDS/ISIS formatting language, HTML, programming languages, operating systems, open source software, and so on.Originality/valueThere is detailed documentation available for most of these packages, but little previous guidance to help potential users to distinguish and choose between them.

Anticonvulsant Treatment for Psychiatric and Seizure Indications Among Youths

Anticonvulsant Treatment for Psychiatric and Seizure Indications Among Youths

A new system to analyze the temporal changes of the event-related brain potential associated with offset of saccades

When we measure the visual event-related potential (ERP), a subject has to fix eyes to a point on the display in an experimental situation or in a diagnosis on the visual function. Therefore, it is very hard to apply the event-related potential (ERP) to assessment of sensation and attention at clinical fields or at industrial settings. We developed a system to analyze the brain potential associated with offset of saccadic eye movements. The potential is called eye fixation-related potential (EFRP). EFRP is identical with the so-called visual ERP. We can measure the topographical change of EFRP in real time. The first system with a UNIX (Version 1) was very fast, but very expensive. However, the new system (Version 2) is more economical, because it can be used in a notebook computer with Windows XP. EEG and EOG data can be sampled in real time, although the data are analyzed offline. The new system will be useful to study cognitive factors under eye movement conditions.

Real-time concurrent collection on stock multiprocessors

We've designed and implemented a copying garbage-collection algorithm that is efficient, real-time, concurrent, runs on commercial uniprocessors and shared-memory multiprocessors, and requires no change to compilers. The algorithms uses standard virtual-memory hardware to detect references to "from space" objects and to synchronize the collector and mutator threads. We've implemented and measured a prototype running on SRC's 5-processor Firefly. It will be straightforward to merge our techniques with generational collection. An incremental, non-concurrent version could be implemented easily on many versions of Unix.

TreeSAAP: selection on amino acid properties using phylogenetic trees.

The software program TreeSAAP measures the selective influences on 31 structural and biochemical amino acid properties during cladogenesis, and performs goodness-of-fit and categorical statistical tests.

Unix version of BioAPI set for second quarter launch

Unix version of BioAPI set for second quarter launch

Flexible Soft Real-Time Processing in Middleware

As desktop computer computational power continues to increase dramatically, it is becoming commonplace to run a combination of deadline-sensitive applications. Despite the proliferation of computational power, the detailed nature of these applications causes new problems for the system resource allocation mechanisms. First, these applications are designed to meet their deadlines as long as nearly all the system’s resources are available to them; once the system approaches saturation, the collective applications will fail to meet their deadlines. To aggravate the situation, conventional best effort managers will allocate resources to the competing applications based on a static form of equitability rather than addressing the dynamic relative benefit provided by each application. Second, the applications differ from conventional real-time applications: though members of this new class of desktop applications are sensitive to deadlines, their constraints are non-critical. They are also typically designed to use the full spectrum of functions provided by a general purpose system call interface rather than the more limited interface of a real-time operating system (OS). This paper describes a flexible soft real-time system design that addresses these two problems. The CPU scheduling strategy accommodates the community of applications by taking application benefit into account during times of heavy load. Applications are written to use the full interface of a general purpose system call interface, yet the system is able to schedule them according to their deadlines and resource reservation and availability. This paper describes the theoretical foundation of the approach, additional application responsibilities, the design of a middleware system to implement the approach, and then it presents an extensive set of experimental studies that demonstrate the behavior of the approach. The Dynamic QoS Manager middleware (implemented on top of two different versions of Unix), is shown to be a highly effective system for supporting contemporary soft real-time desktop applications.

Reversing course: Issues in modeling legacy systems

The Enhanced Traffic Management System (ETMS) is a legacy system used by the Federal Aviation Administration (FAA) to support air traffic flow management. Air traffic flow management is the strategic control of air traffic to minimize delays and congestion and maximize the throughput of aircraft throughout the National Airspace System (NAS). This paper discusses the reasons for modeling a legacy system, problems and advantages encountered in modeling an operational system, and describes the construction of a simulation model of ETMS. Originally written in Pascal to run on Apollo workstations under the Aegis Domain operating system, ETMS has been converted to C/C++ and ported to HP servers and workstations running HP-UX, a POSIX-compliant version of UNIX. The objectives of the modeling task were to assess performance of the ported system and to provide a basis for evaluating a possible redesign/re-architecture of the system. The initial plan was to develop one or two models aimed at the network aspects (both LAN and WAN) of ETMS at a relatively high level, and then to develop a more detailed model to look at specific workstation/server issues. As is shown in this paper, issues of existing system design and documentation and the availability (or the lack) of data continually arose. Nevertheless, a reasonable set of working assumptions were derived which allowed modeling and evaluation to proceed. Thus, the quantitative and qualitative results obtained provided information and lessons learned that can be built upon. Moreover, the second of the stated goals (to provide a basis for possible redesign) was also achieved because there is now a baseline for future design/architecture studies. The focus of this paper is to provide insights into the issues involved in modeling an existing system rather than the results of the model itself.

Transmeta's magic show [microprocessor chips

It took Transmeta engineers $100 million, five years of secret toil, and a little magic to create fast low-power chips that turn into x86s in a microsecond. Transmeta Corporation's Crusoe chips look nothing like Intel's Pentium processors. They do not even have a logic gate in common. They are smaller, consume between one-third and one-thirtieth the power (depending on the application), and implement none of the same instructions in hardware. However the Crusoe microprocessors can run the same software that runs on IBM PC-compatible personal computers with Pentium chips-for instance, Microsoft Windows or versions of Unix, along with their software applications. The paper describes the development of the Crusoe chips.