902 research outputs found
The Domestic Market for Short-term Debt Securities
The market for short-term debt is dominated by the issuance of bank securities. Yields on these securities act as an important reference rate within the financial system. The turmoil in global markets during recent years has led to significant changes in the short-term debt market as the funding profiles of banks and other issuers of short-term securities has altered.short-term debt; prime banks; BBSW; ABCP; LIBOR; OIS
A Flexible Image Processing Framework for Vision-based Navigation Using Monocular Image Sensors
On-Orbit Servicing (OOS) encompasses all operations related to servicing satellites and performing other work
on-orbit, such as reduction of space debris. Servicing satellites includes repairs, refueling, attitude control and
other tasks, which may be needed to put a failed satellite back into working condition.
A servicing satellite requires accurate position and orientation (pose) information about the target spacecraft.
A large quantity of different sensor families is available to accommodate this need. However, when it comes to
minimizing mass, space and power required for a sensor system, mostly monocular imaging sensors perform very
well. A disadvantage is- when comparing to LIDAR sensors- that costly computations are needed to process the
data of the sensor.
The method presented in this paper is addressing these problems by aiming to implement three different design
principles; First: keep the computational burden as low as possible. Second: utilize different algorithms and
choose among them, depending on the situation, to retrieve the most stable results. Third: Stay modular and
flexible.
The software is designed primarily for utilization in On-Orbit Servicing tasks, where- for example- a servicer
spacecraft approaches an uncooperative client spacecraft, which can not aid in the process in any way as it is
assumed to be completely passive. Image processing is used for navigating to the client spacecraft. In this specific
scenario, it is vital to obtain accurate distance and bearing information until, in the last few meters, all six degrees
of freedom are needed to be known. The smaller the distance between the spacecraft, the more accurate pose
estimates are required.
The algorithms used here are tested and optimized on a sophisticated Rendezvous and Docking Simulation facility
(European Proximity Operations Simulator- EPOS 2.0) in its second-generation form located at the German
Space Operations Center (GSOC) in WeĂling, Germany. This particular simulation environment is real-time capable
and provides an interface to test sensor system hardware in closed loop configuration. The results from these
tests are summarized in the paper as well.
Finally, an outlook on future work is given, with the intention of providing some long-term goals as the paper is
presenting a snapshot of ongoing, by far not yet completed work. Moreover, it serves as an overview of additions
which can improve the presented method further
Modeling, Stability Analysis, and Testing of a Hybrid Docking Simulator
A hybrid docking simulator is a hardware-in-the-loop (HIL) simulator that
includes a hardware element within a numerical simulation loop. One of the
goals of performing a HIL simulation at the European Proximity Operation
Simulator (EPOS) is the verification and validation of the docking phase in an
on-orbit servicing mission.....Comment: 30 papge
Control Strategy of Hardware-in-the-Loop Simulator EPOS 2.0 for Autonomous Docking Verification
This paper briefly describes the hybrid simulator system called European Proximity Operation Simulator (EPOS 2.0) and the
development of the hardware-in-the-loop (HIL) docking simulation concept. A critical requirement for the docking simulation
of this HIL simulator is that the 6-DOF robots in the loop have to exactly mimic the dynamic response of the two satellites
during a contact operation. The main challenges to meet this requirement are in the stiffness of the robots, which is unlike
that of the satellites, as well as the time delay in the HIL simulator. The paper mainly presents the impedance parameter
identification concept for matching the impedance between the satellites impact model and the EPOS robots. In addition
it presents the contact dynamics model used, and the control strategies to meet the requirements of the docking simulator.
Finally it presents the preliminary results and future work
Analisis pengembangan karier yang dipengaruhi oleh kepemimpinan, budaya organisasi, dan prestasi kerja
This research is an explanatory of causality in the public organization, aims to analyze the influence of leadership, organizational culture and employess performance to career development and to analyze the dominant influence among leadership, organizational culture and employess performance to career development. The population in this study are employees of government organizations. The sampling technique is a census where all the populations (62 employees) become sample. The results of this study shows that leadership, organizational culture, and employess performance significantly influence career development. Employess performance is the dominant variable affecting the career development of employees. The key of career development is the employess performance, therefore the organization should always improve the skills and knowledge of their employess through education and training, so that employees can improve their performance from time to time. It will determine the development of their career
Analytical and experimental stability investigation of a hardware-in-the-loop satellite docking simulator
The European Proximity Operation Simulator (EPOS) of the DLR-German Aerospace
Center is a robotics-based simulator that aims at validating and verifying a
satellite docking phase. The generic concept features a robotics tracking
system working in closed loop with a force/torque feedback signal. Inherent
delays in the tracking system combined with typical high stiffness at contact
challenge the stability of the closed-loop system. The proposed concept of
operations is hybrid: the feedback signal is a superposition of a measured
value and of a virtual value that can be tuned in order to guarantee a desired
behavior. This paper is concerned with an analytical study of the system's
closed-loop stability, and with an experimental validation of the hybrid
concept of operations in one dimension (1D). The robotics simulator is modeled
as a second-order loop-delay system and closed-form expressions for the
critical delay and associated frequency are derived as a function of the
satellites' mass and the contact dynamics stiffness and damping parameters. A
numerical illustration sheds light on the impact of the parameters on the
stability regions. A first-order Pade approximation provides additional means
of stability investigation. Experiments were performed and tests results are
described for varying values of the mass and the damping coefficients. The
empirical determination of instability is based on the coefficient of
restitution and on the observed energy. There is a very good agreement between
the critical damping values predicted by the analysis and observed during the
tests...Comment: 16 page
On Probabilities in the Many Worlds Interpretation of Quantum Mechanics
Quantum Mechanics notoriously faces a measurement problem, the problem that the unitary time evolution, encoded in its dynamical equations, together with the kinematical structure of the theory generally implies the non-existence
of definite measurement outcomes. There have been multiple suggestions to solve this problem, among them the so called many worlds interpretation that originated with the work of Hugh Everett III. According to it, the quantum state and time evolution fully and accurately describe nature as it is, implying that under certain conditions multiple measurement outcomes that are seemingly mutually exclusive can be realized at the same time â but as different 'worlds' contained in a global, quantum mechanical structure, sometimes referred to as 'the multiverse'. The many worlds interpretation has, however, been confronted with serious difficulties over the course of its development, some of which were solved by the advent of decoherence theory. The present thesis critically investi-
gates the state of play on a key remaining problem of the many worlds interpretation, the problem of the meaning and quantiďŹcation of probabilities in a quantum multiverse. Recent attempts of deriving the pivotal statistical ingredient of quantum mechanics, Bornâs rule, from either principles of decision theory or from quantum mechanics alone, supplemented with a few general premises about
probability are analyzed and their premises are scrutinized. It will be argued that, though both approaches yield promising results, they both ultimately fail
to clearly establish the validity of Bornâs rule in the context of the many worlds interpretation. It is hence suggested that further research on this problem is indicated
PEMBERDAYAAN SUMBER DAYA MANUSIA, RESILIENSI ORGANISASI, DAN KINERJA ORGANISASI PADA INDUSTRI JASA
Objective of the research was to examine empirically the influence of human resources empowerment, directly and indirectly, through organization resilience on an organization performance. Objectives of the research in detail were to analyze and examine empirically the influences of: human resources empowerment on organization performance, human resources empowerment on organization resilience, and organization resilience on organization performance. Population of the research was 69 star hotels, which spread over the East Java Province. 34 hotels were taken as samples. The respondents were 216 managers. Samples were taken using proportional sampling method and data analysis of the research used SEM (Structural Equation Model). The main finding of this research was that the organization performance would be enhanced if the human resources were empowered in participating to achieve the organization goal, commit to the organization, and have greater authority and responsibility in decision-making process. This influence will be stronger if it is followed by the organization capability to adapt to any change at the organization environment
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