Modern breaking of Enigma ciphertexts

“Breaking German Army Ciphers” is the title of a Cryptologia article from 2005, describing the lucky survival of several hundred authentic Enigma messages of World War II, and an account of a ciphertext-only cryptanalysis of a large number of these messages, leaving only a few (mostly short messages) unbroken. After reviewing the work done, and investigating the reasons for both lucky breaks and close misses, the modern ciphertext-only attack on Enigma messages is improved, especially on genuine ones with short lengths and/or many garbles. The difficulties of a proper measure for the candidate’s closeness to a plaintext are clarified. The influence on the decryption process of an empty plugboard and one with only a few correct plugs is examined. The method is extended by a partial exhaustion of the plugboard combined with an optimized hillclimbing strategy. The newly designed software succeeds in breaking formerly unbroken messages.     

A pulsed plasma thruster fault detection and isolation strategy for formation flying of satellites

The main objective of this paper is to develop a dynamic neural network-based fault detection and isolation (FDI) scheme for pulsed plasma thrusters (PPTs) that are employed in the attitude control subsystem (ACS) of satellites tasked to perform formation flying (FF) missions. A hierarchical methodology is proposed that consists of three fault detection and isolation (FDI) approaches, namely (i) a “low-level” FDI scheme, (ii) a “high-level” FDI scheme, and (iii) an “integrated” FDI scheme. Based on the data from the electrical circuit of the PPTs, the proposed “low-level” FDI scheme can detect and isolate faults in the PPT actuators with a good level of accuracy, however the precision level is poor and below expectations with the misclassification rates as expressed by False Healthy and False Faulty parameters being too high. The proposed “high-level” FDI scheme utilizes data from the relative attitudes of the FF mission. This scheme has good detection capabilities, however its isolation capabilities are not adequate. Finally, the proposed “integrated” FDI scheme takes advantage of the strengths of each of the above two schemes while reducing their individual weaknesses. The results demonstrate a high level of accuracy (99.79%) and precision (99.94%) with a misclassification rates that are quite negligible (less than 1%). Furthermore, the proposed “integrated” FDI scheme provides additional and interesting information related to the effects of faults in the thrust production levels that would not have been available from simply using the low or the high level schemes alone.     

Adaptive Pinpoint and Fuel Efficient Mars Landing Using Reinforcement Learning

Future unconstrained and science-driven missions to Mars will require advanced guidance algorithms that are able to adapt to more demanding mission requirements, e.g. landing on selected locales with pinpoint accuracy while autonomously flying fuel-efficient trajectories. In this paper, a novel guidance algorithm designed by applying the principles of reinforcement learning (RL) theory is presented. The goal is to devise an adaptive guidance algorithm that enables robust, fuel efficient, and accurate landing without the need for off line trajectory generation and real-time tracking. Results from a Monte Carlo simulation campaign show that the algorithm is capable of autonomously following trajectories that are close to the optimal minimum-fuel solutions with an accuracy that surpasses that of past and future Mars missions. The proposed RL-based guidance algorithm exhibits a high degree of flexibility and can easily accommodate autonomous retargeting while maintaining accuracy and fuel efficiency. Although reinforcement learning and other similar machine learning techniques have been previously applied to aerospace guidance and control problems (e.g., autonomous helicopter control), this appears, to the best of the authors knowledge, to be the first application of reinforcement learning to the problem of autonomous planetary landing.      

GEHEIMSCHREIBER

World War II's “Fish” cipher was a British cover word for all kinds of encrypted German radio teleprinter messages. The GC&CS at Bletchley, Buckinghamshire, did not only attack successfully Enigma traffic (Morse signals on radio links) by the electromechanical deciphering machines called BOMBES. In addition, Bletchley's electronic text processor COLOSSUS broke the German “Tunny” ciphers, generated by TELEPRINTER ATTACHMENTS “SZ”, employed by the ‘Heer’ (Army) on HF radio links.     

无人飞行器集群智能调度技术综述

随着飞行器技术的快速发展, 以无人机和卫星为代表的无人飞行器在集群任务中得到广泛应用, 但日益增长的多样化任务需求和不平衡、不充足的任务资源也对无人飞行器集群调度技术提出新的挑战.针对无人飞行器任务类型特点, 分别从无人机群和多星两个角度出发, 介绍了无人机群访问、打击和察打一体化任务调度技术进展, 阐述了多星成像、数传与天地一体化任务调度研究成果.同时, 梳理了无人机群和多星任务调度问题的主要约束与收益指标, 综述了无人机群和多星任务调度常用的智能优化算法.最后, 面向未来无人飞行器技术应用需求, 指出了无人飞行器集群智能调度技术进一步的研究方向.     

Traditional organizations and crisis management in transition—Organizational perspectives on new dynamics of independent civil engagement

Digitalization and the trend towards more short‐term and project‐oriented social engagement have had a direct impact on traditional crisis management. This societal change has supported the evolution of new types of volunteers who use low‐threshold potentials to organize and maintain support independently. Traditional institutions like the German Red Cross are challenged to deal with these rapid changes regarding their own organizational culture in relation to the new phenomenon of so‐called unaffiliated volunteers. This paper investigates how unaffiliated volunteers influence and change the organizational culture of German disaster management by analysing and reflecting organizational adaptation processes in the aftermath of the German floods in 2013, the storm events in the west of Germany in 2014 and the refugee relief mission in 2015–2016. Therefore, semi‐structured interviews with experts of the German Red Cross were held to analyse their reactions towards unaffiliated Volunteers during the Floods in 2013 and the refugee relief missions, and further focus group interviews were conducted to validate the extracted results. Findings suggest that among professionals and leading entities in the German Red Cross, a process of rethinking has emerged, recognizing the importance and necessity to open up organizational structures for the collaboration and coordination of unaffiliated volunteers.     

Cooperative Large Area Surveillance with a Team of Aerial Mobile Robots for Long Endurance Missions

This paper proposes a distributed approach to solve long duration area surveillance missions with a team of aerial robots, taking into account communication constraints. The system, based on “one-to-one” coordination, minimizes the probability that any event happens in the area without being detected and ensures periodic communication between UAVs. A set of simulations are presented to validate the applicability of the approach and its most relevant features: convergence, robustness with dynamic teams, fault-tolerance and finite information sharing time. It is also shown that “one-to-one” coordination for all the pairs of neighbors allows to obtain an efficient coordination scheme for the whole team to accomplish the area surveillance mission without any central unit.     

Extension of a ground control interface for swarms of Small Drones

Although the technology for fully autonomous swarms of robots is rapidly progressing, the human operator will continue to play an important role during any swarming mission due to safety, monitoring and control constraints. In this paper, we present the set of features that a Ground Control Interface (GCI) must incorporate to allow monitoring, control and safety of outdoor missions with a swarm of Small Drones (drones of less than 1 kg). We propose a new extension to a widely used GCI by incorporating those features and we demonstrate its usage on a swarm of 10 Small Drones flying outdoor.     

Development of entertainment balloon robot system for an indoor event venue

This project revolves around the combination of different state-of-the-art concepts to create balloon robots which can be used for entertainment purposes. The goal is having multiple robots perform a choreographed flight on preset paths to make use of the “dead space” over the crowd of an event, either as part of the show or displaying information and advertisements. As the balloon is flying on a defined trajectory, a tracking system for its position is needed. For this purpose, several infrared cameras monitor the position of a marker attached to the balloon. The main challenge is overcoming the instabilities of the system to ensure a smooth and precise flight, resulting from the balloons structure: the balloon is filled with helium to counteract the forces of gravity and, therefore, minimize the work needed to keep its momentum. Finding a way to achieve this optimization and the precision mentioned beforehand is the task that we will present and solve in this paper.     

基于马尔科夫链的平台生存任务模型与航路评估

在地面雷达武器威胁环境里,不仅需要评估航路上飞行平台的有关生存和任务完成的概率,而且还要能度量不同航路的好坏。由于传统模型不能有效表达生存模型和任务模型,更不能有效统一生存模型与任务模型,为此建立了基于马尔科夫链的生存任务模型,并且在此模型的基础上引入代价来评估航路。最后的仿真结果表明,该方法有效刻画了生存率和任务完成率,能关注到完成任务且无伤害返回的概率,并且能有效度量航路的好坏。     

Towards a framework of key technologies for drones

The potential applications for drones, especially those in manned areas or into non-segregated airspace, are currently not possible without the development and validation of certain key enabling technologies: “detect and avoid”, “air traffic management”, “command and control (C2) link”, and “security and cyber resilience”. This issue has a high impact on European innovation as identified by SESAR JU and demands R&D investments and incentives for the convergence of shared technologies and markets. In this paper, we discuss the vision of COMP4DRONES project to complement SESAR JU efforts with a particular focus on safe software and hardware drone architectures. COMP4DRONES will bear a holistically designed ecosystem ranging from application to electronic components. The ecosystem aims at supporting (1) efficient customization and incremental assurance of drone-embedded platforms, (2) safe autonomous decision making concerning individual or cooperative missions, (3) trustworthy drone-to-drone and drone-to- ground communications even in presence of malicious attackers and under the intrinsic platform constraints, and (4) agile and cost-effective design and assurance of drone modules and systems. Lead applications driving ecosystem development and benchmarking on the fields of transport, inspection, logistic, precision agriculture, and parcel delivery will be produced.     

A group AHP-TOPSIS framework for human spaceflight mission planning at NASA

Human spaceflight mission planning is a complex task with many interacting systems and mission phases. Analog missions are Earth-based science missions whose purpose is to help understand the complexities inherent in future human spaceflight missions. The goal of performing an analog mission is to prepare crewmembers and support teams for future space missions in a low risk-low cost environment by repeatedly testing vehicles, habitats, and surface terrain simulators. This study presents a group multi-attribute decision making (MADM) framework developed at the Johnson Space Center (JSC) for the Integrated human exploration mission simulation facility (INTEGRITY) project to assess the priority of human spaceflight mission simulators. The proposed framework integrates subjective judgments derived from the analytic hierarchy process (AHP) with the entropy information and the technique for order preference by similarity to the ideal solution (TOPSIS) into a series of preference models for the human exploration of Mars. Three different variations of TOPSIS including conventional, adjusted and modified TOPSIS methods are considered in the proposed framework.     

Team NimbRo at MBZIRC 2017: Fast landing on a moving target and treasure hunting with a team of micro aerial vehicles

The Mohamed Bin Zayed International Robotics Challenge (MBZIRC) 2017 has defined ambitious new benchmarks to advance the state‐of‐the‐art in autonomous operation of ground‐based and flying robots. This study covers our approaches to solve the two challenges that involved micro aerial vehicles (MAV). Challenge 1 required reliable target perception, fast trajectory planning, and stable control of an MAV to land on a moving vehicle. Challenge 3 demanded a team of MAVs to perform a search and transportation task, coined “Treasure Hunt,” which required mission planning and multirobot coordination as well as adaptive control to account for the additional object weight. We describe our base MAV setup and the challenge‐specific extensions, cover the camera‐based perception, explain control and trajectory‐planning in detail, and elaborate on mission planning and team coordination. We evaluated our systems in simulation as well as with real‐robot experiments during the competition in Abu Dhabi. With our system, we—as part of the larger team NimbRo—won the MBZIRC Grand Challenge and achieved a third place in both subchallenges involving flying robots.     

Optimal surveillance coverage for teams of micro aerial vehicles in GPS-denied environments using onboard vision

This paper deals with the problem of deploying a team of flying robots to perform surveillance-coverage missions over a terrain of arbitrary morphology. In such missions, a key factor for the successful completion of the mission is the knowledge of the terrain’s morphology. The focus of this paper is on the implementation of a two-step procedure that allows us to optimally align a team of flying vehicles for the aforementioned task. Initially, a single robot constructs a map of the area using a novel monocular-vision-based approach. A?state-of-the-art visual-SLAM algorithm tracks the pose of the camera while, simultaneously, autonomously, building an incremental map of the environment. The map generated is processed and serves as an input to an optimization procedure using the cognitive, adaptive methodology initially introduced in Renzaglia et?al. (Proceedings of the IEEE international conference on robotics and intelligent system (IROS), Taipei, Taiwan, pp.?3314–3320, 2010). The output of this procedure is the optimal arrangement of the robots team, which maximizes the monitored area. The efficiency of our approach is demonstrated using real data collected from aerial robots in different outdoor areas.     

Accessing Egypt: making myths and producing web sites in cyber-Cairo

From an anthropological viewpoint, “accessibility” is not so much a technological and design project as it is a cultural construction, a cognitive schema through which graphic designers and technologists imagine audiences and create appropriate graphic designs that will be “accessible” to that audience. The ethnographer's task is the specification of key actors, institutions and discourses active in the making and remaking of accessibility in a given context. In this article, we examine how Egyptian Web producers at the turn of millennium (1999–2001) sought to design Web portals that would allow the “typical” Egyptian to easily access the World Wide Web. We argue, first, that Egyptian Web producers are deeply influenced by national and international discourses that frame IT as a national mission for socioeconomic development. Second, we found that in the absence of clear definitions of the Web audience, Web producers imagined a “typical” Egyptian that contradicted their own experiences of users of the Web. Finally, we found that Egyptian Web producers largely borrowed pre-existing models, using design elements to “inflect” their sites with an Egyptian motif. However, the conceptual models of access and related design strategies created by Egyptian Web producers were out of touch with Egyptian social realities, contributing to a collapse of most Web portal projects.     

Cognitive Automation for Tactical Mission Management: Concept and Prototype Evaluation in Flight Simulator Trials

This paper describes an approach to cognitive and cooperative operator assistance in the field of tactical flight mission management. A framework for a generic functional concept is derived from general considerations of human performance and cognitive engineering. A system built according to these human-centred design principles will be able to keep up with the change of situation parameters, in order to provide situational adapted operator assistance. Such a cognitive assistant system represents an approach to ensure the highest degree possible of situation awareness of the flight deck crew as well as a satisfactory workload level. This generic approach to mission management and crew assistance for military aircraft has been realised in different application domains such as military transport and air-to-ground attack. The Crew Assistant Military Aircraft is a functional prototype for the air transport application. Even applications in the domain of uninhabited aerial vehicles (UAV) are in reach. This paper mainly covers one state-of-the-art research and development activity in the domain of combat aircraft: the TMM – Tactical Mission Management System is an experimental solution for the air-to-ground attack role. The TMM has been implemented as a functional prototype in the mission avionics experimental cockpit (MAXC), a development flight simulator at ESG and evaluated with German Air Force pilots as subjects in simulator trials. Therefore, the TMM has been compared with a reference cockpit avionics configuration in terms of task performance, workload, situation awareness and operator acceptance. After giving an overview of the system concepts this paper reports on the experimental design and results of the simulator trial campaign.     

COLOSSUS AND THE BREAKING OF THE WARTIME “FISH” CODES

One of the authors of the recently released “General Report on Tunny,” here describes his three-year experience as a founder member of the “Testery” and “New-manry” teams. Their combined use of innovative methods and machines led from the breaking of the German Lorenz military traffic to its large-scale daily decipherment.     

METIS-II: low resource machine translation

METIS-II was an EU-FET MT project running from October 2004 to September 2007, which aimed at translating free text input without resorting to parallel corpora. The idea was to use “basic” linguistic tools and representations and to link them with patterns and statistics from the monolingual target-language corpus. The METIS-II project has four partners, translating from their “home” languages Greek, Dutch, German, and Spanish into English. The paper outlines the basic ideas of the project, their implementation, the resources used, and the results obtained. It also gives examples of how METIS-II has continued beyond its lifetime and the original scope of the project. On the basis of the results and experiences obtained, we believe that the approach is promising and offers the potential for development in various directions.     

On-orbit servicing: a time-dependent, moving-target traveling salesman problem

The robotic capability of maintaining and repairing space assets, on‐orbit servicing (OOS), has the potential to change the way spacecraft are designed, manufactured and operated. The most common OOS mission concept envisions an orbital “depot”, where consumables and spare parts for spacecraft will be stored. A “servicing platform”, based at this depot, will be used to service a number of client spacecraft and then return to the depot for resupply. We model OOS as a time‐dependent, moving‐target traveling salesman problem and present an algorithm for minimizing the total amount of energy or time required for OOS operations.