A universal setup for active control of a single-photon detector

The influence of bright light on a single-photon detector has been described in a number of recent publications. The impact on quantum key distribution (QKD) is important, and several hacking experiments have been tailored to fully control single-photon detectors. Special attention has been given to avoid introducing further errors into a QKD system. We describe the design and technical details of an apparatus which allows to attack a quantum-cryptographic connection. This device is capable of controlling free-space and fiber-based systems and of minimizing unwanted clicks in the system. With different control diagrams, we are able to achieve a different level of control. The control was initially targeted to the systems using BB84 protocol, with polarization encoding and basis switching using beamsplitters, but could be extended to other types of systems. We further outline how to characterize the quality of active control of single-photon detectors.Comment: 10 pages, 10 figure

Conceptual Ecological Modelling of Shallow Sublittoral Coarse Sediment Habitats to Inform Indicator Selection

The purpose of this study is to produce a series of Conceptual Ecological Models (CEMs)that represent the Shallow Sublittoral Coarse Sediment Habitat in the UK. CEMs are diagrammatic representations of the influences and processes that occur within an ecosystem. They can be used to identify critical aspects of an ecosystem that may be taken forward for further study, or serve as the basis for the selection of indicators for environmental monitoring purposes. The models produced by this project are 'control diagrams', representing the state of the environment free from adverse anthropogenic impacts and pressures

Statistics Control of Process Described by Attributive and Continues Variable

Tato práce má za cíl přiblížit problematiku regulačních diagramů. První část shrnuje poznatky o regulačních diagramech včetně jejich rozdělení podle typu sledované veličiny. Jednotlivé druhy diagramů jsou podrobně popsány. Druhá část se zabývá praktický využitím regulačních diagramů při použití reálných dat. Na datech jsou použity testy vymezitelných příčin a hledají se příčiny selhání. Klíčové je posouzení stability procesu.This thesis aimes at approaching the problem of control diagrams. The first part summarizes the theoretical knowledge about the control diagrams, including their sorting based on the type of the monitored quantity. The different types of diagrams are described in detail. The second part deals with the practical use of control diagrams using actual data. Tests of definable causes are used on these data, and the causes of failure are sought. The key is to assess process stability.

Finite control set model predictive control-a powerful control algorithm for grid-connected power converters

© 2016 IEEE. This paper presents a detailed description of Finite Control Set Model Predictive Control applied to power converters. Some key features related to this methodology are presented and compared with model predictive control based space vector modulation methods. The basic models, principles, control diagrams, and simulation results are presented to provide a comparison between them. The analysis is performed on a three-phase/ two-level voltage source inverter, which is one of the most common converter topologies used in industry. Among the conclusions are the feasibility and great potential of Finite Control Set Model Predictive Control due to the advanced signal-processing capability, particularly for power systems with a reduced number of switching states and more complicated principles

Controlling passively-quenched single photon detectors by bright light

Single photon detectors based on passively-quenched avalanche photodiodes can be temporarily blinded by relatively bright light, of intensity less than a nanowatt. I describe a bright-light regime suitable for attacking a quantum key distribution system containing such detectors. In this regime, all single photon detectors in the receiver Bob are uniformly blinded by continuous illumination coming from the eavesdropper Eve. When Eve needs a certain detector in Bob to produce a click, she modifies polarization (or other parameter used to encode quantum states) of the light she sends to Bob such that the target detector stops receiving light while the other detector(s) continue to be illuminated. The target detector regains single photon sensitivity and, when Eve modifies the polarization again, produces a single click. Thus, Eve has full control of Bob and can do a successful intercept-resend attack. To check the feasibility of the attack, 3 different models of passively-quenched detectors have been tested. In the experiment, I have simulated the intensity diagrams the detectors would receive in a real quantum key distribution system under attack. Control parameters and side effects are considered. It appears that the attack could be practically possible.Comment: Experimental results from a third detector model added. Minor corrections and edits made. 11 pages, 10 figure

Controlling passively-quenched single photon detectors by bright light

Single photon detectors based on passively-quenched avalanche photodiodes can be temporarily blinded by relatively bright light, of intensity less than a nanowatt. I describe a bright-light regime suitable for attacking a quantum key distribution system containing such detectors. In this regime, all single photon detectors in the receiver Bob are uniformly blinded by continuous illumination coming from the eavesdropper Eve. When Eve needs a certain detector in Bob to produce a click, she modifies polarization (or other parameter used to encode quantum states) of the light she sends to Bob such that the target detector stops receiving light while the other detector(s) continue to be illuminated. The target detector regains single photon sensitivity and, when Eve modifies the polarization again, produces a single click. Thus, Eve has full control of Bob and can do a successful intercept-resend attack. To check the feasibility of the attack, 3 different models of passively-quenched detectors have been tested. In the experiment, I have simulated the intensity diagrams the detectors would receive in a real quantum key distribution system under attack. Control parameters and side effects are considered. It appears that the attack could be practically possible.Comment: Experimental results from a third detector model added. Minor corrections and edits made. 11 pages, 10 figure

Generation of Whole-Body Expressive Movement Based on Somatical Theories

An automatic choreography method to generate lifelike body movements is proposed. This method is based on somatics theories that are conventionally used to evaluate human’s psychological and developmental states by analyzing the body movement. The idea of this paper is to use the theories in the inverse way: to facilitate generation of artificial body movements that are plausible regarding evolutionary, developmental and emotional states of robots or other non-living movers. This paper reviews somatic theories and describes a strategy for implementations of automatic body movement generation. In addition, a psychological experiment is reported to verify expression ability on body movement rhythm. This method facilitates to choreographing body movement of humanoids, animal-shaped robots, and computer graphics characters in video games

The Analysis of Total Dissolved Iron from Mud Sedimentation Ponds Wastewater in PT Bukit Asam (Persero) Tbk Tanjung Enim Using Individual Control Diagram

The tests have been carried out on the iron content of wastewater in the inlet and outlet of the mud sedimentation ponds PT Bukit Asam (Persero) Tbk Tanjung Enim, South Sumatra Province. The iron concentration in mining waste water that does not comply with government standards of 7.0000 mg / L can pollute the environment. The measurement of iron concentration was carried out by Atomic Absorption Spectrophotometer (AAS) method in accordance with SNI 06-6989.4: 2004. Analysis of iron concentration using calibration curve methods and individual control diagrams. The results of data analysis showed that the iron content of the inlet and outlet MSP (Mud Sedimentation Ponds) wastewater was still under the standard set with an average value of 1.4488 mg/L inlet and outlet 0.4061 mg/L. Based on the results of the study the concentration of iron meets the established quality standards

Dual Channel Control with DC Fault Ride Through for MMC-based, Isolated DC/DC Converter

This study is sponsored by the Engineering and Physical Sciences Research Council (EPSRC) grant no EP/K006428/1, 2013.D. Jovcic and H. Zhang are with the School of Engineering, University of Aberdeen, AB24 3UE, U.K. ([email protected], [email protected]).Peer reviewedPostprin