With the establishment of U.S. Cyber Command, the cyber force is gaining visibility and authority, but challenges remain, particularly in the areas of acquisition and personnel recruitment and career ...progression. A review of commonalities, similarities, and differences between the still-nascent U.S. cyber force and early U.S. special operations forces, conducted in 2010, offers salient lessons for the future direction of U.S. cyber forces.
This book provides the most detailed analysis yet of the failure of U.S. nation-building in the Vietnam War. In doing so, it demolishes the “better war” school of writing on the topic, which argues ...that the U.S. was successful in building a legitimate and viable non-Communist state in South Vietnam in the latter years of the war. Drawing on fresh archival collections and previously unseen oral histories with dozens of U.S. nation-builders, the book demonstrates that the U.S. never came close to achieving victory. The book’s narrative stretches from the offices in Washington in which policy was designed down into the villages in which it was implemented, providing the most comprehensive analysis yet of the largest and best-resourced nation-building program in U.S. history. Only by understanding and facing the reasons for this failure can we avoid repeating the tragic mistake of the Vietnam War again in the future.
At the pinnacles of organizations, comparative tests of unity of command and shared command are nearly impossible because only one individual sits atop most organizations. In organizations led by ...co-CEOs, however, such a test is possible because co-CEOs can truly share power. But do they? Our research pits the unity-of-command principle against the shared-command principle and finds overall support for the former, even within the co-CEO context. Our sample of 71 co-CEO pairs at publicly traded U.S. firms shows that increasing power gaps between co-CEOs are positively associated with firm performance. This positive association wanes and turns negative, however, as power gaps become very large. We conclude that whatever benefits the co-CEO structure might offer likely lie outside the shared command paradigm.
Cognitive work analysis Jenkins, Daniel P
c2009., 2009, 2008-12-01, 2017-09-18, 2017-06-12
eBook
'Complex sociotechnical systems' are systems made up of numerous interacting parts, both human and non-human, operating in dynamic, ambiguous and safety critical domains. Cognitive Work Analysis ...(CWA) is a structured framework specifically developed for considering the development and analysis of these complex socio-technical systems. Unlike many human factors approaches, CWA does not focus on how human-system interaction should proceed (normative modelling) or how human-system interaction currently works (descriptive modelling). Instead, through a focus on constraints, it develops a model of how work can be conducted within a given work domain, without explicitly identifying specific sequences of actions (formative modelling).
This study develops a fuzzy finite-time command filtered position tracking control approach for induction motors with input saturation. First, the fuzzy logic systems are utilised to approximate the ...non-linear functions. Then, in order to avoid the ‘explosion of complexity’ in backstepping design, the finite-time command filter is employed. In addition, error compensating signals are introduced to decrease the errors produced by command filters. The fuzzy finite-time adaptive command filtered controllers can guarantee that the tracking error can converge in finite time. The results of simulation show the effectiveness of the proposed method.
Wide-ranging changes have been made to the North American Aerospace Defense Command (NORAD) since 2006, when the binational agreement was signed in perpetuity. NORAD traces the joint command's recent ...history - one marked by technological and structural innovations, but also by unprecedented threats and challenges.
Air traffic controllers' (ATCos) workload often is a limiting factor for air traffic capacity. Thus, electronic support systems intend to reduce ATCos' workload. Automatic speech recognition can ...extract controller command elements from verbal clearances to deliver automatic input for air traffic control systems, thereby avoiding manual input. Assistant Based Speech Recognition (ABSR) with high command recognition rates and low error rates has proven to dramatically reduce ATCos’ workload and increase capacity in approach scenarios. However, ABSR needs accurate hypotheses on expected commands and accurate extractions of command annotations from utterance transcriptions to achieve the required performance. Based on the experience of implementation for approach control, a hypotheses generator and a command extractor have been developed for speech recognition applications regarding tower control communication to face current and future challenges in the aerodrome environment. Three human-in-the-loop multiple remote tower simulation studies were performed with 16 ATCos from Hungary, Lithuania, and Finland at DLR Braunschweig from 2017 to 2019. Roughly 100 h of speech with corresponding radar data were recorded. Around 6000 speech utterances resulting in 16,000 commands have been manually transcribed and annotated. Some parts of the data have been used for training prediction models and command extraction algorithms. Other parts were used for evaluation of command prediction and command extraction. The automatic command extractor achieved a command extraction rate of 96.7%. The hypotheses generator showed operational feasibility with a sufficiently low command prediction error rate of 7.3%.
•Assistant Based Speech Recognition for Aerodrome Air Traffic Control.•First Implementation of Tower Command Hypotheses Generator and Command Extractor.•Multiple Remote Tower Trials with 16,000 commands from 16 Air Traffic Controllers.•Command Prediction Error Rate regarding Gold Annotations is 7.3%.•Command Extraction Rate of Annotations on Manual Transcriptions is 96.7%.
Operating cranes is challenging because payloads can experience large and dangerous oscillations. The oscillations are induced by both intentional motions commanded by the human operator and by ...external disturbances. Although significant progress has been achieved by using command shaping to reduce operator-induced vibration, less success has been achieved on reducing oscillations induced by external disturbances, such as wind. The disturbance-rejection task is more challenging because it requires accurate sensing of the crane payload. This study presents a combined command shaping and feedback control architecture. The input shaper eliminates the payload oscillation caused by human-operator commands, and the feedback controller reduces the effect of wind gusts. Simulations of a large range of motions are used to analyse the dynamic behaviour of boom cranes using the proposed controller. Experimental results obtained from a small-scale boom crane validate the simulated dynamic behaviour and the effectiveness of the controller.
This book presents an exhaustive review and evaluation of contemporary theoretical perspectives on SA and of a range of SA measurement approaches. A novel theory of DSA in complex sociotechnical ...systems is presented, followed by an original methodology for assessing SA and DSA in command and control environments. It contains several naturalistic case studies of command and control scenarios undertaken in numerous military domains, as well as one involving multiple high-consequence civilian domains.
