Search results for "software engineering"
showing 10 items of 1151 documents
Can visualization alleviate dichotomous thinking? Effects of visual representations on the cliff effect
2021
Common reporting styles for statistical results in scientific articles, such as $p$ p -values and confidence intervals (CI), have been reported to be prone to dichotomous interpretations, especially with respect to the null hypothesis significance testing framework. For example when the $p$ p -value is small enough or the CIs of the mean effects of a studied drug and a placebo are not overlapping, scientists tend to claim significant differences while often disregarding the magnitudes and absolute differences in the effect sizes. This type of reasoning has been shown to be potentially harmful to science. Techniques relying on the visual estimation of the strength of evidence have been recom…
Toward Optimal LSTM Neural Networks for Detecting Algorithmically Generated Domain Names
2021
Malware detection is a problem that has become particularly challenging over the last decade. A common strategy for detecting malware is to scan network traffic for malicious connections between infected devices and their command and control (C&C) servers. However, malware developers are aware of this detection method and begin to incorporate new strategies to go unnoticed. In particular, they generate domain names instead of using static Internet Protocol addresses or regular domain names pointing to their C&C servers. By using a domain generation algorithm, the effectiveness of the blacklisting of domains is reduced, as the large number of domain names that must be blocked g…
GekkoFS - A Temporary Distributed File System for HPC Applications
2018
We present GekkoFS, a temporary, highly-scalable burst buffer file system which has been specifically optimized for new access patterns of data-intensive High-Performance Computing (HPC) applications. The file system provides relaxed POSIX semantics, only offering features which are actually required by most (not all) applications. It is able to provide scalable I/O performance and reaches millions of metadata operations already for a small number of nodes, significantly outperforming the capabilities of general-purpose parallel file systems. The work has been funded by the German Research Foundation (DFG) through the ADA-FS project as part of the Priority Programme 1648. It is also support…
LPCC
2019
Most high-performance computing (HPC) clusters use a global parallel file system to enable high data throughput. The parallel file system is typically centralized and its storage media are physically separated from the compute cluster. Compute nodes as clients of the parallel file system are often additionally equipped with SSDs. The node internal storage media are rarely well-integrated into the I/O and compute workflows. How to make full and flexible use of these storage media is therefore a valuable research question. In this paper, we propose a hierarchical Persistent Client Caching (LPCC) mechanism for the Lustre file system. LPCC provides two modes: RW-PCC builds a read-write cache on…
A configurable rule based classful token bucket filter network request scheduler for the lustre file system
2017
HPC file systems today work in a best-effort manner where individual applications can flood the file system with requests, effectively leading to a denial of service for all other tasks. This paper presents a classful Token Bucket Filter (TBF) policy for the Lustre file system. The TBF enforces Remote Procedure Call (RPC) rate limitations based on (potentially complex) Quality of Service (QoS) rules. The QoS rules are enforced in Lustre's Object Storage Servers, where each request is assigned to an automatically created QoS class.The proposed QoS implementation for Lustre enables various features for each class including the support for high-priority and real-time requests even under heavy …
Challenges and Solutions for Tracing Storage Systems
2018
IBM Spectrum Scale’s parallel file system General Parallel File System (GPFS) has a 20-year development history with over 100 contributing developers. Its ability to support strict POSIX semantics across more than 10K clients leads to a complex design with intricate interactions between the cluster nodes. Tracing has proven to be a vital tool to understand the behavior and the anomalies of such a complex software product. However, the necessary trace information is often buried in hundreds of gigabytes of by-product trace records. Further, the overhead of tracing can significantly impact running applications and file system performance, limiting the use of tracing in a production system. In…
UML/OCL-based modeling of work-based access control policies for collaborative healthcare systems
2016
A work-based access control (WBAC) model is proposed by introducing the team role concept and modifying the user-role assignment model from a previous work. The main goals of WBAC are flexibility, easy manageability, security, as well as suitability to support cooperative work of dynamic teams in healthcare environments. One of the major challenges of WBAC regards authorization constraints in terms of organizational policies. In this article, we show how Unified Modeling Language (UML) and Object Constraints Language (OCL) are utilized to design and analyze the authorization constraints of WBAC in cooperative engagements with complex scenarios in the collaborative healthcare domain. We also…
DeCyMo: Decentralized Cyber-physical System for Monitoring and Controlling Industries and Homes
2018
The recent revolution of the Internet of Things has given the birth of a series of new technologies and cyber-physical systems to be used in industrial and home scenarios. Cyber- physical systems include physical and software components for providing smart monitoring and control with flexibility and adaptability to the operating context. The IoT paradigm enables the intertwined use of physical and software components through the interconnection of devices that exchange data with each other without direct human interaction in several fields, especially in industrial and home environments. We propose DeCyMo, a decentralized architecture that aims at solving common IoT issues and vulnerabiliti…
General and flexible methodology and architecture for CAPP: GF-CAPP system
2003
Although all researchers insist on the need to develop computer-aided process planning (CAPP) systems, they agree that one of its most significant shortfalls is the low level of generality and flexibility present in current proposals. One of the outcomes of this low level of generality--apart from its limited application domain--is the low level of integration achieved with CAD, CAM and PP&C systems. To ensure optimized running of the production system, it is also important to stress the need to develop alternative process planning that enables it to adapt to disruptions in production. Several factors play an important role in implementing these features, among which the following may be hi…
Towards a Reference Architecture for Model-Driven Business Apps
2016
Model-driven development techniques have been proposed for cross-platform app development. Typically, an individual domain-specific language (DSL) is used. The MD² framework consists of a DSL for business apps and generators, which transform a domain model to native platform code. Prior research on it focused on language and general generator design, this paper accentuates the code generation stage. A reference architecture for the generated apps is proposed to accelerate the development of new generators for which architectural decisions had been made on ad-hoc basis up to now. Moreover, generators are going to expose similar structures that facilitate maintenance. Our proposal takes MD²'s…