IoTranx: Transactions for Safer Smart Spaces

Smart spaces such as smart homes deliver digital services to optimize space use and enhance user experience. They are composed of an Internet of Things (IoT), people, and physical content. They differ from traditional computer systems in that their cyber-physical nature ties intimately with the users and the built environment. The impact of ill-programmed applications in such spaces goes beyond loss of data or a computer crash, risking potentially physical harm to the space and its users. Ensuring smart space safety is therefore critically important to successfully deliver intimate and convenient services surrounding our daily lives. By modeling smart space as a highly dynamic database, we present IoT Transactions, an analogy to database transactions, as an abstraction for programming and executing the services as the handling of the devices in smart space. Unlike traditional database management systems that take a “clear room approach,” smart spaces take a “dirty room approach” where imperfection and unattainability of full control and guarantees are the new normal. We identify Atomicity, Isolation, Integrity and Durability (AI 2 D) as the set of properties necessary to define the safe runtime behavior for IoT transactions for maintaining “permissible device settings” of execution and to avoid or detect and resolve “impermissible settings.” Furthermore, we introduce a lock protocol, utilizing variations of lock concepts, that enforces AI 2 D safety properties during transaction processing. We show a brief proof of the protocol correctness and a detailed analytical model to evaluate its performance.

MODELING AND ANALYSIS OF A VEHICLE DYNAMICS AT FRONTAL IMPACT INTO THE RIGID BARRIER USING A SYSTEM IDENTIFICATION TOOLBOX

The main objective of this paper is to create computer crash models (up to the level of the Kelvin model, where the coefficient of stiffness and damping is calculated by implementing appropriate numerical methods: Trust - Region, Lavenberg-Marquardt and so on) of measured real data that are obtained at the frontal impact of a vehicle into the rigid barrier. The process of modeling a vehicle crash can be done in two ways. One of them is related to CAE (Computer Aided Engineering) software including FEA. The other one (applied in this article) is based on the System Identification Toolbox, which contains MATLAB® functions, Simulink® blocks, and a special app for constructing models of dynamic systems from the measured input-output data.

Conceptual approach to understanding and exploring the cultural meaning of computer according to Jeffrey Alexander

<p>Human phenomena are Significant and all works that are created by humans can carry meaning. These meanings are cultural constructs. Understanding of these meanings is the task of cultural sociology. The main goal of the cultural sociology is to show aspects of the collective unconsciousness. This result is based on unconscious cultural structures that lead society to the ideas of the Enlightenment. However, the process of understanding may change, but the structure does not break apart because Society cannot survive without these structures.</p><p>In this research, we ask one question: “what is cultural meaning of Computer based on cultural sociology theory of Jeffrey C. Alexander”? This study seeks to determine the cultural meaning of computer with Knowledge and method of cultural sociology; also we try to understand symbols, codes and narratives about computer according to Alexander.</p><p>According to Alexander, computers were coded as good or sacred since its entry into the west public sphere and were presented the good narrative from it, such as salvation narrative, eschatology narrative and Apocalypse narrative. But gradually, the good times ended and the dark side of the computer crash on human and romantic story with computer showed its pathological aspects. Gradually the cultural meaning of computer was different in social life in the West. Computers were coded as an aspect of evil. Population gradually saw the computers as unholy or profane. Computers became the Frankenstein monster in West.</p>

Forensic Engineering Investigation of a Three-Vehicle Accident

An accident involving three vehicles resulted in serious injuries to one of the drivers. It was alleged that the driver was injured because both of the other operators were inattentive and made driving errors. Through the use of electronic data retrieval and computer crash simulation, it was shown that only one of the non-injured drivers made a driving error. A computer-aided dynamic crash simulation program (PC-Crash) was used to show the motion of the vehicles after impact. Because no formal police report was completed for the accident, electronic data retrieval and computer-aided engineering methods were needed to fill in the data voids. Witness statements, in conjunction with the reconstructed data, allowed a better understanding of the mechanisms involved in both the primary and secondary collisions.

Optimal Computer Crash Performance Precaution

Distributed Computing and Networking International audience For a parallel computer system with m identical computers, we study optimal performance precaution for one possible computer crash. We want to calculate the cost of crash precaution in the case of no crash. We thus define a tolerance level r meaning that we only tolerate that the completion time of a parallel program after a crash is at most a factor r + 1 larger than if we use optimal allocation on m - 1 computers. This is an r-dependent restriction of the set of allocations of a program. Then, what is the worst-case ratio of the optimal r-dependent completion time in the case of no crash and the unrestricted optimal completion time of the same parallel program? We denote the maximal ratio of completion times f(r, m) - i.e., the ratio for worst-case programs. In the paper we establish upper and lower bounds of the worst-case cost function f (r, m) and characterize worst-case programs.

The Constitutional Assembly Database Project-Resurrecting a Database Ten Years On

In 1995 the Constitutional Assembly Database Project (the Project) began to publish the proceedings of South Africa's Constitutional Assembly on the Internet. The Project finished this work, the first of its kind anywhere in the world, in 1996, but the Database has not been available since a computer crash in 2000. This paper is the first account of the history of the Project. The paper argues that it is important to restore access to the Database, but in a way that will not repeat the mistakes made when setting up the database.