Acoustic characterization of jet interaction with launch structures during lift-off

The structures that constitute the environment surrounding the launchvehicle affectthe noise levels experiencedbyit during liftoff. Earlier studies modeled the launch scenario by incorporating a jet impinging on plate geometries,either flat or curved, ignoring contributions from the components of the launch structures such as the launchplatform. Very little is knownaboutthe effect of the structures on the propagationof noise from the jet exhaust towardthe vehicle. This renders any effort to modify them for noise reduction quite challenging. The present study attemptsto address this concern by investigating the contribution of a principal launch structure component, namely, thelaunch platform, toward the acoustic and flowfield around a generic launch vehicle exhausting on a generic jet blastdeflector. The measurements include flowfield visualizations and aeroacoustic measurements using microphones inthe near and far field. The results indicate that the presence of the launch platform increased the noise levelsexperienced by the vehicle beyond certainL∕De. It is also observed that replacing the solid launch platform with aperforated one leads to lower levels of noise compared to the solid one but still higher than the case where launchplatform is absent

Automated Plant Disease Recognition using Tasmanian Devil Optimization with Deep Learning Model

Plant diseases have devastating effects on crop production, contributing to major economic loss and food scarcity. Timely and accurate recognition of plant ailments is vital to effectual disease management and keeping further spread. Plant disease classification utilizing Deep Learning (DL) has gained important attention recently because of its potential to correct and affect the detection of plant diseases. DL approaches, particularly Convolutional Neural Networks (CNNs) demonstrate that extremely effective in capturing intricate patterns and features in plant leaf images, allowing correct disease classification. In this article, a Tasmanian Devil Optimization with Deep Learning Enabled Plant Disease Recognition (TDODL-PDR) technique is proposed for effective crop management. The TDODL-PDR technique derives feature vectors utilizing the Multi-Direction and Location Distribution of Pixels in Trend Structure (MDLDPTS) descriptor. Besides, the deep Bidirectional Long Short-Term Memory (BiLSTM) approach gets exploited for the plant disease recognition. Finally, the TDO method can be executed to optimize the hyperparameters of the BiLSTM approach. The TDO method inspired by the foraging behaviour of Tasmanian Devils (TDs) effectively explores the parameter space and improves the model's performance. The experimental values stated that the TDODL-PDR model successfully distinguishes healthy plants from diseased ones and accurately classifies different disease types. The automated TDODL-PDR model offers a practical and reliable solution for early disease detection in crops, enabling farmers to take prompt actions to mitigate the spread and minimize crop losses

OSTINATO: Cross-host Attack Correlation Through Attack Activity Similarity Detection

Modern attacks against enterprises often have multiple targets inside the enterprise network. Due to the large size of these networks and increasingly stealthy attacks, attacker activities spanning multiple hosts are extremely difficult to correlate during a threat-hunting effort. In this paper, we present a method for an efficient cross-host attack correlation across multiple hosts. Unlike previous works, our approach does not require lateral movement detection techniques or host-level modifications. Instead, our approach relies on an observation that attackers have a few strategic mission objectives on every host that they infiltrate, and there exist only a handful of techniques for achieving those objectives. The central idea behind our approach involves comparing (OS agnostic) activities on different hosts and correlating the hosts that display the use of similar tactics, techniques, and procedures. We implement our approach in a tool called Ostinato and successfully evaluate it in threat hunting scenarios involving DARPA-led red team engagements spanning 500 hosts and in another multi-host attack scenario. Ostinato successfully detected 21 additional compromised hosts, which the underlying host-based detection system overlooked in activities spanning multiple days of the attack campaign. Additionally, Ostinato successfully reduced alarms generated from the underlying detection system by more than 90%, thus helping to mitigate the threat alert fatigue problemComment: 21 pages, 5 figure

Between Worlds: Securing Mixed JavaScript/ActionScript Multi-Party Web Content

Mixed Flash and JavaScript content has become increasingly prevalent; its purveyance of dynamic features unique to each platform has popularized it for myriad Web development projects. Although Flash and JavaScript security has been examined extensively, the security of untrusted content that combines both has received considerably less attention. This article considers this fusion in detail, outlining several practical scenarios that threaten the security of Web applications. The severity of these attacks warrants the development of new techniques that address the security of Flash-JavaScript content considered as a whole, in contrast to prior solutions that have examined Flash or JavaScript security individually. Toward this end, the article presents FlashJaX, a cross-platform solution that enforces fine-grained, history-based policies that span both Flash and JavaScript. Using in-lined reference monitoring, FlashJaX safely embeds untrusted JavaScript and Flash content in Web pages without modifying browser clients or using special plug-ins. The architecture of FlashJaX, its design and implementation, and a detailed security analysis are exposited. Experiments with advertisements from popular ad networks demonstrate that FlashJaX is transparent to policy-compliant advertisement content, yet blocks many common attack vectors that exploit the fusion of these Web platforms