Adaptive Delta Modulation

A novel measurement method has been developed to characterize the common-mode (CM) and differential-mode (DM) impedances of power line EMI chokes under realistic loading conditions. With a proper pre-measurement calibration process, all parasitic effects in the measurement setup can be eliminated. The measurement allows designer to assess the EMI suppression performance of these chokes with reasonable accuracy under various loading conditions. With the measurement results, a proper choke with optimum EMI suppression performance could be selected for a specific loading condition.

Recent advancement in 3D digitization techniques have prompted to the need for 3D object retrieval. Our method of comparing 3D objects for retrieval is based on 3D morphing. It computes, for each 3D object, two spatial feature maps that describe the geometry and topology of the surface patches on the object, while preserving the spatial information of the patches in the maps. The feature maps capture the amount of effort required to morph a 3D object into a canonical sphere, without performing explicit 3D morphing. Fourier transforms of the feature maps are used for object comparison so as to achieve invariant retrieval under arbitrary rotation, reflection, and non-uniform scaling of the objects. Experimental results show that our method of retrieving 3D models is very accurate, achieving a precision of above 0.86 even at a recall rate of 1.0.

Rule Based Fuzzy Cognitive Maps (RBFCM) are proposed as an evolution of Fuzzy Causal Maps (FCM) that allow a more complete representation of cognition, since relations other than monotonic causality are made possible. Their structure is based on traditional fuzzy systems with feedback. The main problem to solve while trying to implement a RBFCM is the causal relation itself, since traditional fuzzy operations can not implement causality as it is usually defined in causal maps. This paper introduces Rule Based Fuzzy Cognitive Maps and presents a method to implement Fuzzy Causal Relations. This method allows a great flexibility in the addition and removal of concepts and links among concepts, and introduces a new Fuzzy Operation that simulates the "accumulative" property of causal relations -the Fuzzy Carry Accumulation (FCA).

Performances of ∆Σ modulators are evaluated by applying a coherently sampled tone and by estimating powers of the in-band tones and noise. In particular, the power of the shaped noise is usually estimated by subtracting the evaluated input tone from the output data and by integrating the power spectral density estimated by means of the periodogram. Although the coherency, the finite number of processed samples induces spectral leaking of the wideband noise, thus affecting the noise power estimate. To cope with such an issue, usually data are weighted by the Hanning sequence. In this paper, the noise power estimation error induced by the use of such window is investigated, and a criterion for choosing the minimum number of samples N which bounds the relative leakage error within a specified maximum value is explicitly given. Moreover, it is shown that, for any N , such an error is negligible for modulator orders lower than 3. Higher order modulators require the use of a large number of samples to bound the relative error of the noise power estimate when high oversampling ratios are employed.

Fire danger models identify fuel moisture content (FMC) of live vegetation as a critical variable, since it affects fire ignition and propagation. FMC can be calculated by dividing equivalent water thickness (EWT) by dry matter content (DM). The "leaf optical properties spectra" (PROSPECT) model was inverted to estimate EWT and DM separately using the Leaf Optical Properties Experiment (LOPEX) database, based on 490 measurements of leaf optical and biochemical properties. DM estimations were poor when leaf samples were fresh ( 2 = 0 38). Results of a sensitivity analysis conducted on the spectral response of samples demonstrated that water absorption masks the effects of DM on the spectral response. This causes a poor estimation of FMC ( 2 = 0 33), even though EWT estimation was good ( 2 = 0 94). However, DM of dry samples was accurately estimated ( 2 = 0 84), since no water was present. FMC estimation in fresh leaf material improved considerably ( 2 = 0 89) by accounting for DM in fresh samples ( 2 = 0 71), when a constant species-dependent DM value is used. A similar approach was taken on a canopy level by linking the PROSPECT leaf model with the Lillesaeter infinitive reflectance canopy model using data from laboratory measurements under controlled conditions. As expected, results indicate grater difficulty to estimate DM and FMC on a canopy level, although similar trends were observed. DM estimation improved from 2 = 0 12 to 2 = 0 39 when considering measurements of dry samples, which when used for FMC estimation, correlations increase from 2 = 0 62 to 2 = 0 81. Therefore, DM can be accurately estimated only when plant material is dry, and it is a necessary measurement in order to estimate FMC accurately. DM remains stable over annual time periods although lower values are expected during the drought season. However, time variations in DM are smaller than DM variations among species. Because there is also a decrease in water Manuscript

One important class of Data Mining applications is the so-called "Web Mining" that analyzes and extracts important and non-trivial knowledge from Web related data. Typical applications of Web Mining are represented by the personalization or recommender systems. These systems are aimed to extract knowledge from the analysis of historical information of a web server in order to improve the web site expressiveness in terms of readability and content availability. Typically, these systems are made up of two components. One, that is usually executed off-line with respect to the Web server normal operations, analyzes the server access logs in order to find a suitable categorization of users, the other, that is usually executed on-line with respect to the Web server normal operations, classifies the active requests according to the previous off-line analysis. In this paper we propose SUGGEST 2.0 a recommender system that, differently from those proposed so far, does not make use of any off-line component. Moreover, in the last part of the paper, we analyze the quality of the suggestions generated and the performance of our solution. To this purpose we also introduce a novel quality metric that tries to estimate the effectiveness of a recommender system as the capacity to anticipate user requests that could be issued farther in the future.

Today, money laundering poses a serious threat not only to financial institutions but also to the nations. This criminal activity is becoming more and more sophisticated and seems to have moved from the cliché of drug trafficking to financing terrorism and surely not forgetting personal gain. Most international financial institutions have been implementing anti-money laundering solutions to fight investment fraud. On the other hand, cloud-based applications are merging daily and bringing to clients with lower cost of platforms and data storage, greater scalability and improved business continuity. Hence, more financial instituitions aim to move their IT infrastructure to the cloud. However, accessing directly to the customer transaction datasets by a third party could be a confidential issue. This approach is more severe when these solutions are built by collaborating partners. Traditional methods are based on data access agreement but there is still a risk of infringing privacy. In order to preserve the privacy of datasets, different data disguising methods have been proposed. Nevertheless, analysing disguised datasets is a performance issue in the context of detecting suspicious money laundering cases where the real value of data has an important impact. Indeed, the results of analysis could also be a privacy issue. Within the scope of a collaboration project for developing a new cloud-based solution for the Anti-Money Laundering Units in an international investment bank, in this paper, we propose new cloud-based approach using data disguising methods applied in analysing transaction datasets. We also show that the creating relevant dimensions from the current ones is efficient for analysing transaction datasets in terms of both detecting suspicious case and privacy preserving.

In this paper we present a new interaction technique based on degrees of freedom (DoF) decomposition for accurate positioning in virtual reality environments. This technique (called DIOD for Decomposition and Integration Of Degrees of freedom) is based on an adaptation of the Two-Component Model. It provides two different control levels regarding DoF coordination, one integrating and one separating the manipulation of the DoF. Our hypothesis is that each control level is appropriated to a different phase of the positioning task. During the ballistic phase, users manipulate all the dimensions of the task at the same time. However, during the control phase, users try to manipulate specific dimensions individually. The results of a preliminary study we conducted seem to indicate that the DIOD technique is more efficient than existing techniques.

In dual frame video coding, one short-term reference frame and one longterm reference frame are available for motion compensation. In prior research, it was shown that overall video quality was improved by allocating bits unevenly among frames so as to periodically create a high-quality frame that could serve as the long-term reference frame for some time. We extend this work to a cognitive radio scenario where pulses of extra bandwidth can be rented by the second, but rental agreements can be cancelled on short notice if the legacy user of that spectrum returns. With a scalable video coder, this pulse of extra bandwidth can be used to improve the quality of the current frame being encoded, or of the past long term frame, or can be spent on future frames if the encoder has access to them in advance. We compare these various uses to explore the advantages of allocating some of the available bandwidth to past or future frames.

The effect of filtering the time trajectories of spectral envelopes on speech intelligibility was investigated. Since LPC cepstrum forms the basis of many automatic speech recognition systems, we filtered time trajectories of LPC cepstrum of speech sounds, and the modified speech was reconstructed after the filtering. For processing, we applied low-pass, high-pass and band-pass filters. The results of the accuracy from the perceptual experiments for Japanese syllables show that speech intelligibility is not severely impaired as long as the filtered spectral components have 1) a rate of change faster than 1 Hz when high-pass filtered, 2) a rate of change slower than 24 Hz when low-pass filtered, and 3) a rate of change between 1 and 16 Hz when band-pass filtered.

Policies play a key role in autonomic computing and SOA governance. We will first briefly describe the two domains (autonomic computing and SOA governance) to give the background context of our work within both domains, then consider related work. Software product line (SPL) also will be discussed in this section, as we look at variability descriptors of SPL as a kind of policy.

We have proposed a novel interactive procedure for performing decision analysis, called Robust Interactive Decision-Analysis (RID), which avoids the difficult problems in measuring utility and state probability information associated with traditional decision tree analysis. Instead, the RID method permits a decision maker (DM) to voluntarily and interactively express strong (viz, sure) binary preference for actions, partial decision functions, and full decision functions, and only imprecise probability and utility function assessments. These inputs serve as operators to prune the event probability space and decision space until an optimal choice strategy is obtained. Conceptually, the operation of the RID method can be regarded as a state-space pruning system and the computer implementation of the RID methodology can be viewed as a decision support system. Having described the RID methodology and its theoretical developments, we continue the illustration of the corresponding state-space pruning system and its properties. We also discuss the system principles which we have derived from psychological theories and end-user interface studies as well RID method. as our implementation experiences with the

The popular watermarking method with structured codebook is the Scalar Costa Scheme (SCS) which is highly robust but poorly secure. Known Message Attack (KMA) is a type of the security attacks which its countermeasure is more difficult than others. This paper proposes a novel scheme to increase security of SCS in KMA scenario. For this purpose, the SCS model is extended to a more general model. The security of Generalized SCS (GSCS) is analyzed using residual entropy as a security measure. Then, fundamental trade-off between security and achievable rate of GSCS is proved in KMA scenario. Based on this trade-off and the practical security attack on SCS, a new extension of SCS is proposed, called Surjective-SCS (SSCS). In comparison with SCS, SSCS clearly achieves more security and achievable rate in low Watermark to Noise Ratio (WNR) regime.

The techniques of stochastic computing are applied to the design of a low-cost analogue-in analogue-out integrator, easily capable of time constants of several minutes. The expense of up-down counters is avoided by representing quantities as the proportion of bits which are 'on' in a randomly clocked shift register.

This article presents the development and validation of an autonomous, gas sensitive microdrone that is capable of estimating the wind vector in real time using only the onboard control unit of the microdrone and performing gas distribution mapping (DM). Two different sampling approaches are suggested to address this problem. On the one hand, a predefined trajectory is used to explore the target area with the microdrone in a real-world gas DM experiment. As an alternative sampling approach, we introduce an adaptive ...

In this demo we show a recommender system, called SUGGEST , that dynamically generates links to pages that have not yet been visited by a user and might be of his potential interest. Usually other recommender systems exploit a kind of two-phase architecture composed by an off-line component that analyzes Web server access logs and generates information used by a successive online component that generates recommendations. SUGGEST collapse the two-phase into a single online Apache module. The component is able to manage very large Web sites made up of dinamically generated pages by means of an efficient LRU-based database management strategy. The demo will show the way SUGGEST is able to anticipate users' requests that will be made farther in the future, introducing a limited overhead on the Web server activity 1 .

This article proposes a small digital circuit that can be added to each ADC/DAC parallel port to provide fast streaming serial access and facilitate efficient ATPG. The circuit connectivity can be described in IEEE 1687's instrument connectivity language.

This article proposes a small digital circuit that can be added to each ADC/DAC parallel port to provide fast streaming serial access and facilitate efficient ATPG. The circuit connectivity can be described in IEEE 1687's instrument connectivity language.

Effects of the windowing process, widely investigated by the scientific literature for narrow-band components embedded in white noise, is not sufficiently detailed when signals are corrupted by colored noise. Such a phenomenon can heavily affect the spectral parameters estimation of the noisy signal. In this paper effects of the windowing on the output of analog-to-digital converters with ∆Σ topology, which present a spectrally shaped quantization noise, is analyzed. In particular, the spectral leakage of both narrow-and wideband components is investigated and a criterion for choosing the most appropriate window for any given modulator resolution is given. The proposed analysis validates the use of the Hanning sequence as the optimum two term cosine window to be employed for characterizing low order ∆Σ modulators.

Electromagnetic interference in power converters is a crucial problem for circuit designers. Electromagnetically compliant converter design is required for the safety of an operation. A novel filter design approach considering ground leakage current, different winding styles for common mode choke, tolerance of filter capacitor is proposed in this study to solve the electromagnetic interference problem. In the study, electromagnetic compatibility issue is investigated for a 25 kW, 15 kHz switching frequency, threephase/level T-type grid-connected solar inverter. The test setup is installed based on EN55011 standard, and the interferences emitted by the inverter to the grid through conduction are measured. Then, a filter design is made to prevent these interferences from being transmitted to the grid. After the filter is designed and engaged, the measurements are repeated. So, the noise attenuation of the EMI filter is verified experimentally. Experiences obtained from the hardware modification in the EMI filter, which is designed for an industrial solar inverter, have been discussed. It is observed that the result of conducted emission measurement is within the limits of the EN55011 Class B standard. INDEX TERMS Electromagnetic interference, electromagnetic compatibility, EMI filter, solar inverter, common mode, differential mode.

Developing a capability to track a contamination plume is desirable within both defence and civilian contexts. Example scenarios could include defence humanitarian and disaster relief missions where assistance is required in an area where contaminants have been released into the air as part of a natural disaster, e.g. the Fukushima nuclear disaster in 2011. Contaminants could be chemical, biological, radiological or nuclear. Here, tracking a dynamically moving contamination cloud or plume is essential to understand safe areas of operation. One proposed solution to this challenge is the use of a swarm of uncrewed aerial vehicles (UAVs or drones), carrying appropriate sensors, to locate and dynamically track the contamination plume. Developing such capability is challenging, and one critical step to achieve this is the development and use of an appropriate modelling and simulation capability. Drivers for this simulation based development approach include; the practical challenges for producing a contamination plume for field evaluation of solutions, the complexity involved in developing control mechanisms for a UAV swarm, and the environmental variability which make rapid field evaluation challenging and inconsistent. In this paper, we review current literature associated with modelling and simulation of this capability and propose a way ahead from the identified options. To develop, simulate and test a plume tracking capability as proposed, multiple interrelated components need to be developed. Firstly, an appropriate model of contamination plumes must be developed. This can be used to stimulate the UAV mounted sensors which feed measurements to plume tracking algorithms to collaboratively develop an estimation of the contamination plume. This estimated contamination plume can then bias the control of the UAVs towards regions of higher concentration, hence containing the UAVs in the plume and continuing to sense the contamination. This forms a control loop, adapting the position of the UAVs to track the movement of the plume. We review the current literature for each of these components of a plume tracking system, identify shortcomings or gaps in the existing approaches, and propose an end-to-end solution for modelling, stimulating and simulating this capability. The key findings were as follows; It was identified that there is limited research that presents a fit for purpose model of a contamination plume to stimulate the sensors and control components of a UAV swarm solution. Hence, we investigate this challenge and identify the range of plume modelling approaches. For our simulation purposes, we assess that a Lagrangian approach provides an appropriate balance of plume fidelity with low simulation overheads. When reviewing plume mapping algorithms for a distributed mobile sensor network, we found that limited existing research addresses the dynamic nature of a moving contamination plume. However, that is required for our application. Similarly, the coverage control component, which guides and controls the location of the UAVs, typically address static scenarios when producing optimal control solutions. Some dynamic coverage control approaches are identified but further work is required to provide stability guarantees when coupled with specific plume tracking algorithms. Once combined and integrated, these components will form a suitable simulation environment and implementation approach for UAV based contamination plume tracking solutions.

Stability analysis of high-order delta-sigma loops is a challenge. In this brief, a sufficient design criterion is presented for highorder multibit error-feedback DACs which are especially suitable for high-speed operation. This analytical criterion might be too conservative, but it allows the design of stable, robust, and high-resolution deltasigma DACs. Both analytical and numerical analysis are performed for verification. Also, experimental results of a discrete-component multiplier-free prototype demonstrate 10-bit operation at a very low oversampling ratio of 4.

Filters used in electromagnetic interference suppression are often described in literature on drive systems and have become a standard solution in industry. The effect of the commercial off-the-shelf filter depends significantly on how it is installed. A model that includes the installation parameters is made first and then the parameters of the model are extracted by transfer ratio measurements. One possibility is to include the filter on the dc-bus inside the converter. The differential mode dc-bus filter is well known, but the common-mode dc-bus filter has received little attention. Our model is used to show that the common-mode dc-bus filter can achieve the same or even better suppression of common-mode noise by careful design. The transfer ratio is used to evaluate the performance of filter design.

Microwave SQUID multiplexing has become a key technology for reading out large arrays of X-ray and gamma-ray microcalorimeters with mux factors of 100 or more. The desire for fast X-ray pulses that accommodate photon counting rates of hundreds or thousands of counts per second per sensor drives system design toward high sensor current slew rate. Typically, readout of high current slew rate events is accomplished by increasing the sampling rate, such that rates of order 1 MHz may be necessary for some experiments. In our microwave multiplexed readout scheme, the effective sampling rate is set by the frequency of the flux-ramp modulation (f r) used to linearize the SQUID response. The maximum current slew rate between samples is then nominally Φ 0 f r /2M in (where M in is the input coupling) because it is generally not possible to distinguish phase shifts of > π from negative phase shifts of < −π. However, during a pulse, we know which direction the current ought to be slewing, and this makes it possible to reconstruct a pulse where the magnitude of the phase shift between samples is > π. We describe a practical algorithm to identify and reconstruct pulses that exceed this nominal slew rate limit on the rising edge. Using pulses produced by X-ray transition-edge sensors, we find that the pulse reconstruction has a negligible impact on energy resolution compared to arrival time effects induced by under-sampling the rising edge. This technique can increase the effective slew rate limit by more than a factor of two, thereby either reducing the resonator bandwidth required or extending the energy range of measurable photons. The extra margin could also be used to improve crosstalk or to decrease readout noise.

In this study a first-order asynchronous current-mode sigma-delta modulator has been designed and simulated. Asynchronous sigma-delta modulators eliminate the continuous time sigma-delta modulator's problem of signal-to-noise ratio degradation due to clock jitter by avoiding the use of sampling in the modulator loop. Moreover, they provide a higher signal-to-noise ratio even with low-order filters. Thus, considerably low power consumption can be achieved with fewer circuit components. The current mode enables designers to scale the circuits according to different supply voltages and operating currents. In this work, design steps for an asynchronous sigma-delta modulator have been given taking into account its ideal mathematical model. Novel current comparator architecture is proposed, which is used as a one bit-quantizer. Its working principles are explained. The comparator's operation is verified by the simulations in the asynchronous sigma-delta loop. Simulation results show that a satisfactory performance can be obtained with relatively simple designs, compared to ordinary synchronous continuous time sigma-delta modulators.

This paper considers a Gaussian channel with one transmitter and two receivers. The goal is to maximize the communication rate at the intended/primary receiver subject to a disturbance constraint at the unintended/secondary receiver. The disturbance is measured in terms of the minimum mean square error (MMSE) of the interference that the transmission to the primary receiver inflicts on the secondary receiver. This paper presents a new upper bound for the problem of maximizing the mutual information subject to an MMSE constraint. The new bound holds for vector inputs of any length and recovers a previously known limiting (when the length of the vector input tends to infinity) expression from the work of Bustin et al. The key technical novelty is a new upper bound on the MMSE. This bound allows one to bound the MMSE for all signal-to-noise ratio (SNR) values below a certain SNR at which the MMSE is known (which corresponds to the disturbance constraint). The bound also complements the "single-crossing point property" of the MMSE that upper bounds the MMSE for all SNR values above a certain value at which the MMSE value is known. The MMSE upper bound provides a refined characterization of the phase-transition phenomenon, which manifests, in the limit as the length of the vector input goes to infinity, as a discontinuity of the MMSE for the problem at hand. For vector inputs of size n = 1, a matching lower bound, to within an additive gap of order O(log log(1/MMSE)) (where MMSE is the disturbance constraint), is shown by means of the mixed inputs technique recently introduced by Dytso et al.

Power converters with high switching frequency generate conducted electromagnetic interference (EMI) noise. EMI filters are thus widely used to reduce these conducted noises for the compliance with electromagnetic compatibility standards. In this paper, a high frequency (HF) equivalent circuit model for common mode (CM) chokes used in EMI filters is proposed together with its parameter extraction procedure. This procedure is based on impedance measurements and it incorporates an iterative rational function approximation fitting algorithm to extract the parameters in the model. The proposed model and procedure is applied to a planar CM choke which is used to realize an EMI filter. The simulated results of the filter show good agreement with the experimental ones. This extraction procedure is quite general and it can also be extended to identify the HF model of other passive components.

We have developed a two-dimensional theoretical model. This model allowed us to characterize the MSM photodetector based ZnO. It also allowed us to simulate the dark current and photocurrent of the device with different dimensions of the metal contact of structure. The simulation results were agreed with those of the experiment. We have identified the influence of geometry parameters of the metal contact on the dark current and also on the photocurrent. Calculating the ratio (photocurrent / dark current), allowed us to find the best values of finger width w and finger spacing s of the metal structure leading to a low dark current and at the same time a better absorption of the incident light. The best performance of MSM PD are obtained for the following values s = 14 µm, w = 12 microns. These values have enabled us to obtain a dark current of 25nA and a photocurrent equal to 0.78 µA at a 3V bias.

In this paper, we present a new detector for cognitive radio system based on the Canonical Correlation Significance Test (CCST). Unlike existing CCST approaches, which can only be applied on Multi-Antenna System (MAS), our algorithm can be extended for both Single Antenna System (SAS) and MAS. For SAS, the proposed algorithm exploits the time diversity of cyclostationary signals in order to detect the Primary User (PU) signal. Our simulation results shows that our algorithm outperforms well-known cyclostationary algorithm [9]. For MAS, our algorithm uses both spatial and time diversities to apply the CCST. Numerical results are given to illustrate the performance of our algorithm and verify its efficiency for special noise cases (spatially correlated and spatially colored). The simulation results show the superiority of the performance of the proposed detector compared to the recently CCST proposed algorithm [1].

The presence of obstacles like a tree, buildings, or birds along the path of a drone has the ability to endanger and harm the UAV’s flight mission. Avoiding obstacles is one of the critical challenging keys to successfully achieve a UAV’s mission. The path planning needs to be adapted to make intelligent and accurate avoidance online and in time. In this paper, we propose an energy-aware grid based solution for obstacle avoidance (EAOA). Our work is based on two phases: in the first one, a trajectory path is generated offline using the area top-view. The second phase depends on the path obtained in the first phase. A camera captures a frontal view of the scene that contains the obstacle, then the algorithm determines the new position where the drone has to move to, in order to bypass the obstacle. In this paper, the obstacles are static. The results show a gain in energy and completion time using 3D scene information compared to 2D scene information.

With the increased advent of VSC HVDC with long DC transmission link in power systems, situations have arisen and will be even more frequent in the future, where several distributed generation will be connected on the DC-link for more power transfer capability. As penetration level increases, there is need to predict the limit before violation of voltage and power instability on the DC transmission link and ensure that it does not interfere with the main VSC HVDC system control. In this paper, power sensitivity and algebraic technique is proposed to predict the maximum DG penetration that can be accepted at a particular location on the dc link of VSC HVDC transmission system before violation of voltage and power stability.

We present a call routing application for complex problem solving tasks. Up to date work on call routing has been mainly dealing with call-type classification. In this paper we take call routing further: Initial call classification is done in parallel with a robust statistical Spoken Language Understanding module. This is followed by a dialogue to elicit further taskrelevant details from the user before passing on the call. The dialogue capability also allows us to obtain clarifications of the initial classifier guess. Based on an evaluation, we show that conducting a dialogue significantly improves upon call routing based on call classification alone. We present both subjective and objective evaluation results of the system according to standard metrics on real users.

The paper describes an alternative method of website analysis and optimization that combines methods of web usage and web structure miningdiscovering of web users' behaviour patterns as well as discovering knowledge from the website structure. Its primary objective is identifying of web pages, in which the value of their importance, estimated by the website developers, does not correspond to the real behaviour of the website visitors. It was proved before that the expected visit rate correlate with the observed visit rate of the web pages. Consequently, the expected probabilities of visiting of web pages by a visitor were calculated using the PageRank method and observed probabilities were obtained from the web server log files using the web usage mining method. The observed and expected probabilities were compared using the residual analysis. While the sequence rules analysis can only uncover the potential problem of web pages with higher visit rate, the proposed method of residual analysis can also consider other web pages with a smaller visit rate. The obtained results can be successfully used for a website optimization and restructuring, improving website navigation, and adaptive website realisation.

High-accuracy indoor radio positioning can be achieved by using (ultra) wideband (UWB) radio signals. Multiple fixed anchor nodes are needed to compute the position or alternatively, specular multipath components (SMCs) extracted from radio signals can be exploited. In this work, we study a multipath-based, single-anchor positioning system that acquires directional measurements non-coherently. These non-coherent measurements can be obtained, e.g., from a single-chain mm-wave transceiver with analog beam steering or from a low-complexity ultra-wideband transceiver with switched directional antennas. The directional antennas support the separation of SMCs and the suppression of the undesired diffuse multipath component (DMC) with the benefit that the required signal bandwidth can be drastically reduced. The paper analyzes the Cramér-Rao lower bound (CRLB) on the position estimation error to gain insight in the influence of the system design parameters as well as the impact of the DMC on the position error. The CRLB is compared between the non-coherent antenna setup, a conventional array with coherent processing, and a single-antenna setup. A maximum-likelihood position estimation algorithm is formulated. Its performance is evaluated with synthetically generated data as well as with UWB measurements. We show that the accuracy and robustness are significantly improved due to the processing of angular information. Analyzing the measured data for a line-of-sight link, the median error decreases from 22 down to 7 cm, the measurements better than 20 cm increase from 46 to 95 %, and outliers above 50 cm reduce from 12 to 0 %. INDEX TERMS Radio positioning, single-anchor, Fisher information, position error bound, directional antenna, multipath component, non-coherent array processing.

Medical operation planning requires high precision due to the health risks involved. In virtual reality-based osteotomy operation planning, medical professionals would like to use their hands instead of the controllers for osteotomy plane manipulation. However, using hands as an input method in virtual reality is challenging due to noisy hand tracking. We explored the perceptual structure of precise plane manipulation by conducting a controlled experiment to compare: (1) separable Push-Poke which dynamically selects plane manipulation parameters, (2) separable custom axis with Control-Display gain widget which provides user to select object manipulation parameters, (3) integral pinch-based direct manipulation. The perceptual structure of hand-based plane manipulation techniques is composed of (1) integral and fast direct manipulation and (2) separable slow technique that dynamically selects manipulation parameters.

This paper presents and discusses the results of theoretical approach of the BPL (Broadband over Power Line: 2 MHz-32 MHz) transmission efficiency in 6 kV cable line of selected underground mine. The research verifies its validity through practical measurements. It is followed by the derivation of the power line parameters using the transmission line theory. The tests under the mine conditions were carried out for a specific 6 kV mine cable, with steel armour, for as inductive as well as capacitive coupling of BPL modems with the MV grid. The obtained results are not found so far in the literature and constitute the innovation of the achievement. On the basis of the results the conclusions for practical applications have been formulated.

This paper analyzes a multiplicative data hiding scheme, where the watermark bits are embedded within frames of a Gaussian host signal by two different, but arbitrary, embedding matrices. A closed form expression for the bit error rate (BER) of the optimal detector is derived when the frame sizes tend to infinity. Furthermore, a structure is proposed for the optimal detector which divides the detection process into two main blocks: host signal estimation and decision making. The proposed structure preserves optimality, and allows for a great deal of flexibility: The estimator can be selected according to the a priori knowledge about host signal. For example, if the host signal is an Auto-Regressive (AR) process, we argue that a Kalman filter may serve as the estimator. Compared to a direct implementation of the Neyman-Pearson detector, this approach results in significantly reduced complexity while keeping optimal performance.

Modulated feedback control introduces periodicity. The global attracting property of the periodic points is established for a simple scalar discrete-time system under ∆-modulated feedback. Attracting regions of the periodic points are also characterized. When the discretization effects of the equivalent control based sliding mode control systems are studied, we show that the zero-order-hold discretization gives rise to ∆-modulation in the sliding mode direction. The global attracting property of ∆-modulated feedback offers a vivid illustration of the way sliding happens. Interestingly, we find that a ZOH discretization scheme of the equivalent control based sliding mode control system with relative degree one results in only two-periodic orbits.

In industrial community, there is a growing interest of using single-phase cycloconverters for variable speed drive applications. To employ cycloconverter in variable speed drive applications, the harmonic components of cycloconverter output voltage which is always expressed in terms of total harmonic distortion (THD) should be low to ensure good power quality. Different type of switching pulse width modulation techniques is available to compensate the THD, but the complex modulation techniques increase the complexity of gate drive circuit and hardware implementation process. In this paper, a modified single-phase to single-phase mid-point type cycloconverter topology is proposed which significantly reduces the THD of output voltage for one-third and one-four of 50 Hz frequency conversion without using any type of pulse width modulation techniques for switching. The proposed topology offers promising performances in terms of THD and it also lowers the complexity of gate drive circuit compared to existing solutions. To verify the feasibility of the proposed converter, a laboratory prototype is developed besides MATLAB/Simulink simulation.

This letter presents a hardware-efficient frequency estimator and an advanced phase estimation algorithm capable of tracking the phase noise of a 10-GBaud optical quadrature phase-shift-keying transmission system with standard distributedfeedback lasers in the presence of a frequency mismatch up to 1.2 GHz. This algorithm allows us to implement a digital coherent receiver without an analog frequency control circuit.

This work proposes a new differential cooperative diversity scheme with high data rate and low decoding complexity using the decode-and-forward protocol. The proposed model does not require either differential encoding or channel state information at the source node, relay nodes, or destination node where the data sequence is directly transmitted and the differential detection method is applied at the relay nodes and the destination node. The proposed technique enjoys a low encoding and decoding complexity at the source node, the relay nodes, and the destination node. Furthermore, the performance of the proposed strategy is analyzed by computer simulations in quasi-static Rayleigh fading channel and using the decode-and-forward protocol. The simulation results show that the proposed differential technique outperforms the corresponding reference strategies.