Computer Crash

2003 ◽  
Vol 348 (23) ◽  
pp. 2365-2366 ◽  
Keyword(s):  
Computer Crash

scholarly journals Optimal Computer Crash Performance Precaution

2012 ◽  
Vol Vol. 14 no. 1 (Distributed Computing and...) ◽  
Author(s):  
Efraim Laksman ◽  
Hakan Lennerstad ◽  
Lars Lundberg
Keyword(s):  
Completion Time ◽  
Optimal Allocation ◽  
Parallel Program ◽  
Parallel Computer ◽  
Upper And Lower Bounds ◽  
Worst Case ◽  
Worst Case Ratio ◽  
International Audience ◽  
Computer Crash ◽  
The Cost

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.

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

2021 ◽  
Vol 2021 (2) ◽  
pp. 4496-4500
Author(s):  
JOZEF KMEC ◽  
◽  
JOZEF PAVELKA ◽  
JAROSLAV SOLTES ◽  
◽  
...  
Keyword(s):  
System Identification ◽  
Trust Region ◽  
Real Data ◽  
Frontal Impact ◽  
Rigid Barrier ◽  
Kelvin Model ◽  
Modeling And Analysis ◽  
Engineering Software ◽  
Computer Crash ◽  
Stiffness And Damping

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.

IoTranx: Transactions for Safer Smart Spaces

2022 ◽  
Vol 6 (1) ◽  
pp. 1-26
Author(s):  
Chao Chen ◽  
Abdelsalam (Sumi) Helal ◽  
Zhi Jin ◽  
Mingyue Zhang ◽  
Choonhwa Lee
Keyword(s):  
Physical Nature ◽  
Safety Properties ◽  
Smart Space ◽  
Smart Spaces ◽  
Physical Content ◽  
Daily Lives ◽  
Digital Services ◽  
Full Control ◽  
Computer Crash ◽  
The Impact

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.

Fiery Computer Crash

Science ◽  
2002 ◽  
Vol 298 (5600) ◽  
pp. 1881b-1881
Keyword(s):  
Computer Crash

scholarly journals Forensic Engineering Investigation of a Three-Vehicle Accident

2014 ◽  
Vol 31 (2) ◽  
Author(s):  
Martin E. Gordon
Keyword(s):  
Data Retrieval ◽  
Electronic Data ◽  
Crash Simulation ◽  
Vehicle Accident ◽  
Computer Aided ◽  
Forensic Engineering ◽  
Witness Statements ◽  
Computer Crash ◽  
Engineering Investigation ◽  
Serious Injuries

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.

scholarly journals Computer Crash Simulations in the Development of Child Occupant Safety Policies

2000 ◽  
Vol 154 (3) ◽  
pp. 276 ◽  
Author(s):  
Flaura Koplin Winston ◽  
Kristy B. Arbogast ◽  
Lois A. Lee ◽  
Rajiv A. Menon
Keyword(s):  
Occupant Safety ◽  
Computer Crash ◽  
Child Occupant

Developing Guidelines for Crashworthiness of Light Rail Vehicles in Mixed Fleet Operations

2002 ◽  
Author(s):  
Steven W. Kirkpatrick ◽  
Martin P. Schroeder ◽  
Juan Carlos Valde´s Salazar
Keyword(s):  
Structural Integrity ◽  
Safety Concern ◽  
Light Rail ◽  
Passenger Rail ◽  
Rail Vehicles ◽  
Increased Risk ◽  
Crashworthiness Design ◽  
Computer Crash ◽  
Parametric Analyses ◽  
Risk Parameters

As new passenger rail cars are introduced into existing rail fleets, the potential structural for incompatibility between cars in a collision is a safety concern. Crush damage that occurs when dissimilar strength vehicles collide is concentrated in the weaker vehicle. In a serious collision the deformation of the weaker vehicle could be sufficiently large to intrude into the occupied volume of the operator or passenger compartments. As a result, the strength incompatibility has the potential for increased risk of injury for passengers in the weaker vehicle. The design strategy of many modern rail vehicles is to reduce vehicle weight and incorporate crashworthiness design features to improve safety. This is in contrast to an older design approach where strength requirements, such as a high buff strength, were included to ensure structural integrity. The objective of this study is to assess the collision risk for a mixed rail fleet of different vehicle designs. Collision safety is investigated for three different vehicle types. The crash scenarios investigated include vehicle to vehicle collisions between newly designed cars, between older designed cars, and between a mix of new and old designs. To quantify risk, parameters such as cab crush strength, occupant volume strength, and collision speed are varied in computer crash simulations to uncover potential safety problems associated with mixed car operation. Results from these parametric analyses are presented and utilized to guide the development of new crashworthiness specifications for mixed fleet operation.

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