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Multiple-input-multiple-output (MIMO) systems are of interest for meeting the expected demand for higher data rates and lower delays in future wireless packet data systems. In such systems, it is optimal to simultaneously transmit to multiple users compared with a single user in a single-input-single-output system. In addition, multicarrier systems are of interest to combat frequency-selective fading that is experienced over the larger bandwidth that these future broadband systems will use. The use of dirty paper coding further complicates the matter, because the order in which the users are encoded will affect the rates that they can achieve. A well-designed cross-layer scheduling algorithm must take into account the multiple dimensions of this resource-allocation problem and other quality-of-service (QoS) parameters to fully exploit the communications channel. The scheduling problem is often expressed in terms of optimizing some utility function. Unfortunately, the search space for this optimization problem is extremely large, which prohibits an optimal exhaustive search. To this end, we investigate the use of genetic algorithms to reduce the complexity of the scheduling. This paper builds upon prior work that implements scheduling via genetic algorithms in the context of single-carrier systems using zero-forcing beamforming (ZFB). In this paper, we investigate how the genetic algorithm can be adapted to account for the effect of encoding order on the scheduling and how the scheduling can be extended to a multicarrier system. In particular, we investigate the maximum throughput and proportionally fair scheduling criteria. We demonstrate that the performance of the genetic algorithm is near optimal compared with an exhaustive search at a greatly reduced computational complexity. Furthermore, in the case of a multicarrier orthogonal frequency-division multiplexing (OFDM) system, an increase in capacity is shown relative to the single-carrier case.

This paper presents CoScribe, a concept and prototype system for the combined work with printed and digital documents, which supports a large variety of knowledge work settings. It integrates novel pen-and-paper-based interaction techniques that enable users to collaboratively annotate, link and tag both printed and digital documents. CoScribe provides for a very seamless integration of paper with the digital world, as the same digital pen and the same interactions can be used on paper and displays. As our second contribution, we present empirical results of three field studies on learning at universities. These motivated the design of CoScribe and were abstracted to a generic framework for the design of intuitive pen-and-paper user interfaces. The resulting interaction design comprising collaboration support and multiuser visualizations has been implemented and evaluated in user studies. The results indicate that CoScribe imposes only minimal overhead on traditional annotation processes and provides for a more efficient structuring and retrieval of documents.

Paper recommender systems in the e-learning domain must consider pedagogical factors, such as a paper's overall popularity and learner background knowledge - factors that are less important in commercial book or movie recommender systems. This article reports evaluations of a 6D paper recommender. Experimental results from a human subject study of learner preferences suggest that pedagogical factors help to overcome a serious cold-start problem (not having enough papers or learners to start the recommender system) and help the system more appropriately support users as they learn.

In this paper, a review of the authors' work on inkjet-printed flexible antennas, fabricated on paper substrates, is given. This is presented as a system-level solution for ultra-low-cost mass production of UHF radio-frequency identification (RFID) tags and wireless sensor nodes (WSN), in an approach that could be easily extended to other microwave and wireless applications. First, we discuss the benefits of using paper as a substrate for high-frequency applications, reporting its very good electrical/dielectric performance up to at least 1 GHz. The RF characteristics of the paper-based substrate are studied by using a microstrip-ring resonator, in order to characterize the dielectric properties (dielectric constant and loss tangent). We then give details about the inkjet-printing technology, including the characterization of the conductive ink, which consists of nano-silver particles. We highlight the importance of this technology as a fast and simple fabrication technique, especially on flexible organic (e.g., LCP) or paper-based substrates. A compact inkjet-printed UHF ldquopassive RFIDrdquo antenna, using the classic T-match approach and designed to match the IC's complex impedance, is presented as a demonstration prototype for this technology. In addition, we briefly touch upon the state-of-the-art area of fully-integrated wireless sensor modules on paper. We show the first-ever two-dimensional sensor integration with an RFID tag module on paper, as well as the possibility of a three-dimensional multilayer paper-based RF/microwave structure.

In this paper, the feasibility of inkjet printing of circuit and microwave structures on paper-based substrates is investigated for the first time in the implementation of a complete low-cost wireless platform for sensors. First, the system-level design of the module including the amplifier characterization were carried out to ensure optimum performance of the sensor modules in the UHF bands used in RF identification communication. These results were then used to design two different antenna structures, which are printed on paper along with their respective circuit layouts using inket-printing technology. Different techniques were investigated for the assembly of circuit components on the silver printed layouts. Finally, wireless link measurements on the assembled prototypes verified the good performance on the wireless and sensing sides.

It sounds like a trick question, but it's not: Do white papers need to be either white or paper? Authors are preparing a small but growing number of technical documents today that are intended to be read on a tablet or smartphone screen. And some of these multicolored, multimedia presentations and PowerPoint-style slideshows are having as big an impact as that of any traditionally arranged document.

A wideband Rayleigh fading channel is considered with causal channel state information (CSI) at the transmitter and no receiver CSI. A simple orthogonal code with energy detection rule at the receiver (similar to pulse position modulation in IEEE Trans. Inf. Theory, vol. 46, no. 4, Apr. 2000 and IEEE Trans. Inf. Theory, vol. 52 no. 5, May 2006) is shown to achieve the capacity of this channel in the wideband limit. This strategy transmits energy only when the channel gain exceeds a threshold, hence only needs causal transmitter CSI. In the wideband limit, this capacity without any receiver CSI is the same as the capacity with full receiver CSI, which is proportional to the logarithm of the bandwidth. Similar threshold-based pulse position modulation is shown to achieve the capacity per unit cost of the dirty-tape channel (dirty paper channel with causal transmitter CSI and no receiver CSI), which equals its capacity per unit cost with full receiver CSI. Then, a general discrete channel with i.i.d. states is considered. Each input has an associated cost and a zero cost input “0” exists. The channel state is assumed to be known at the transmitter in a causal manner. Capacity per unit cost is found for this channel and a simple orthogonal code is shown to achieve this capacity. Later, a novel orthogonal coding scheme is proposed for the case of causal transmitter CSI and a condition for equivalence of capacity per unit cost for causal and noncausal transmitter CSI is derived.

This article presents measurements of insulating resistance in distribution transformers, at various temperatures, from which the activation energy of the oil-paper system is calculated.

In this letter, a novel electromagnetic band-gap structure (EBG) with single-ring resonators is inkjet-printed on the commercially available photo paper using conductive nano-silver ink. The printed EBG array is placed above a copper sheet, forming an artificial magnetic conductor (AMC) reflector at the designed frequency range (2.4 ~ 2.5 GHz). A microstrip monopole antenna is backed with the designed AMC reflector and is tested in free space and in contact with a human phantom. The antenna gain of a conventional microstrip monopole on human phantom is as low as -9 dBi. The gain of the proposed AMC backed monopole, measured on a human phantom is 0.95 dBi. The measurements demonstrate superior performance of the proposed monopole with EBG array compared to a conventional microstrip monopole antenna when they are considered for wearable applications.

The 2010 IEEE Journal of Solid-State Circuits Best paper award was given to "An 18 b 12.5 MS/s ADC with 93 dB SNR," by Christopher Peter Hurrell, Colin Lyden, David Laing, Derek Hummerston, and Mark Vickery, published in IEEE Journal of Solid- State Circuits (JSSC), vol. 45, no. 12, pp. 2647?2654, December 2010. According to JSSC Editor-in-Chief Un-Ku Moon, this work was judged the best in JSSC 2010 because "it sets a new performance benchmark for high-resolution CMOS converters, showing a measured SNR of 93 dB at a sampling rate of 12.5 MS/s. Hurrell et al. achieve this level of performance by pipelining two multibit successive approximation converters via a highgain residue amplifier. Through this architectural partition, the presented ADC judiciously unites favorable analog design capabilities and digital enhancements such as weight calibration, redundancy, and dither. The end result is a substantial advancement of the state of the art that stands out in a publication space that is dominated by less intimidating low-to-moderate precision designs."

A hydrogenated amorphous silicon thin-film transistor (a-Si:H TFT) source driver for e-paper was designed with a latch and bootstrap selection circuit. The source driver was optimized by simulation and verified with measurements after circuit fabrication. The output waveforms of the conventional and proposed a-Si:H source drivers were compared. The proposed a-Si:H TFT source driver provided a shorter rise time and higher output voltages than the conventional one.

At present a large range of car-to-car and car-to-infrastructure communication systems is under development. There are hardly publications about expectable EMC and spectrum management problems and some car manufacturers have not cared about these problems in early development stages. The scope of the paper is to identify and assess possible risks and to propose countermeasures.

This paper proposes the use of higher order statistical moments in document image processing to improve the performance of systems which transmit side information through the print and scan channel. Examples of such systems are multilevel 2-D bar codes and certification via text luminance modulation. These systems print symbols with different luminances, according to the target side information. In previous works, the detection of a received symbol is usually performed by evaluating the average luminance or spectral characteristics of the received signal. This paper points out that, whenever halftoning algorithms are used in the printing process, detection can be improved by observing that third and fourth order statistical moments of the transmitted symbol also change, depending on the luminance level. This work provides a thorough analysis for those moments used as detection metrics. A print and scan channel model is exploited to derive the relationship between the modulated luminance level and the higher order moments of a halftone image. This work employs a strategy to merge the different moments into a single metric to achieve a reduced detection error rate. A transmission protocol for printed documents is proposed which takes advantage of the resulting higher robustness achieved with the combined detection metrics. The applicability of the introduced document image analysis approach is validated by comprehensive computer simulations.

Non-destructive diagnosis of power transformer condition is an increasingly important area of research. Power transformer coils are typically insulated with Kraft paper and immersed in mineral oil. There is a clear need to be able to estimate the aged condition of the coil insulation non-destructively. A portable fibre-optic spectroscopic probe system has been developed which can achieve this quickly by determining the degree of polymerization (DP), an indicator of degradation, to an accuracy of 30 DP units. The system can also determine water content to an accuracy of 0.1% w/w, and oil content and condition, very rapidly from the same measurements. The system uses a broadband spectroscopic diffuse reflectance probe operating in the visible and near infrared (NIR) range and interfaced to dedicated multivariate analysis software. Following calibration and measurement trials in the laboratory, the instrument has recently been adapted for use in the field, in which DP predictions have been made from in-situ measurements on the exposed windings of de-tanked transformers. These values have been validated when checked against DP measurements of the same paper taken in parallel using conventional viscometric methods. The system is now being further optimized and is being developed for other applications in the power industry and other industrial areas such as the paper industry and the plastics recycling industry. The system is modular and different probe types can be attached allowing the measurement of a wide variety of solid material surfaces and liquid media.

Multiwalled carbon nanotubes (MWNTs) are characterized at X-, Ku-, Ka-, and Q-bands by rectangular waveguide measurements. The scattering parameters (S-parameters) of thin MWNT papers containing a large ensemble of randomly oriented nanotubes are measured by a vector network analyzer from 8 to 50 GHz. A rigorous extraction algorithm has been developed to compute the effective complex permittivity ( epsiv = epsiv'- jepsiv") and permeability ( mu = mu' - jmu") of the nanotube papers from the measured -parameters. The extracted effective medium parameters are verified by finite-element simulations using Ansoft's High Frequency Structure Simulator (HFSS). The uncertainties for this characterization method are analyzed. The systematic uncertainties are found larger at lower frequencies than at higher frequencies. The extracted conductivity of the nanotube papers is in the range of 810-1500 S/m and the dielectric constant is from 250 to 700. The extracted complex permittivity can be fitted with the Drude-Lorentz model for the 8-50-GHz frequency range. The effective medium theory is then applied to remove the impact of air in the nanotube paper.

Dielectric testing techniques, in both time and frequency domains, are currently widely used by power utilities for assessment of the condition of transformer oil-paper insulation systems. However, it has been reported that results of these tests are highly influenced by the operating temperature during measurements. The distribution, migration and equilibrium of moisture between oil and paper in a complicated insulation system is highly temperature dependent. It requires adequate experience and proper understanding to interpret the dielectric response results in the presence of temperature variations and thermal instability. Proper analysis of the dielectric test result is only possible with an understanding of the physical behavior of the insulation system in response to temperature. A circuit model, which describes the dielectric behavior of the transformers main insulation system, has been investigated in this paper. The values of the parameters of the model have been identified from the dielectric tests. A correlation has been observed between the operating temperature and the equivalent model parameters that can be used as additional information for better interpretation of the dielectric test results. This paper thus reports a detailed study on the effects of temperature on dielectric measurements of a transformer under controlled laboratory conditions. Some results of practical on-site testing are also presented to demonstrate the possibility of errors that may be introduced in dielectric test results analysis unless temperature effects are taken into consideration.

The papers in this special section were presented at the International Solid-State Circuits Conference that was held January 31 to February 4, 2016, in San Francisco, CA.

An RFID system, utilizing a chipless RFID tag on a 90 μm thin Taconic TF290 laminate, is presented. The chipless tag consists of two cross-polarized ultra-wideband antennas and a multi-resonating circuit. The data encoding is performed in the multi-resonating circuit, which is composed of multiple stop-band spiral resonators. The chipless tag encodes data into the spectral signature in both the magnitude and phase of the spectrum. The design and operation of two prototype RFID readers is also presented. The RFID readers operate between 1.9 GHz to 2.5 GHz and 5 GHz to 10.7 GHz, and can successfully detect a chipless tag at close range. The tag design can be easily transferred to plastic and paper, making it suitable for mass deployment for low-cost items. It has the potential to replace trillions of barcodes printed each year. The RFID reader is suitable for mounting over conveyor-belt systems.

In this paper, inkjet-printed UHF and microwave circuits fabricated on paper substrates are investigated for the first time as an approach that aims for a system-level solution for fast and ultra-low-cost mass production. First, the RF characteristics of the paper substrate are studied by using the microstrip ring resonator in order to characterize the relative permittivity (epsivr) and loss tangent (tan delta) of the substrate at the UHF band for the first time reported. A UHF RFID tag module is then developed with the inkjet-printing technology, proving this approach could function as an enabling technology for much simpler and faster fabrication on/in paper. Simulation and well-agreed measurement results, which show very good agreement, verify a good performance of the tag module. In addition, the possibility of multilayer RF structures on a paper substrate is explored, and a multilayer patch resonator bandpass filter demonstrates the feasibility of ultra-low-cost 3-D paper-on-paper RF/wireless structures.

The concept of using cellulose as a smart material for preparing electro-active paper (EAPap) has been a land mark discovery, since it exhibits an impressive magnitude of actuation at relatively modest voltages. Considering the small thickness of cellulose samples (35 mum) and smaller depth of electrodes (100 nm), even at relatively low operating voltages (7 V), high electrical stresses can exist at pointed asperities on electrode surface, non-uniform locations in cellulose structure and at triple points joining electrode, cellulose and air. This paper reports the results of our AC and DC breakdown tests on cellulose samples carried out according to ASTM standards. The variation of breakdown strengths with relative humidity levels has been investigated and the results are explained with the aid of Maxwell-Wagner effect.

In this paper, the influence of the stiffness and damping of real elastic shafts on the behavior of a multidrive system driving a tissue paper machine is investigated. The drive system consists of four DC motors, where two of them drive the Yankee drying cylinder and the other two drive the presses section. Six-pulse thyristor bridge power converters that are connected to the same power transformer supply the motors. The inertias of the motors and the driven machines, in conjunction with the shaft stiffness, form mechanical resonators. Thus, resonance phenomena may occur, which may lead to undesirable results. This particular case results to two three-mass and one five-mass systems. This paper presents an analysis of the resonance frequencies of two sections of the machine during startup and machine production, considering the shaft stiffness (shaft diameter, length, and thickness). The elastic shafts eliminate the ripple of the motor electromagnetic torque, which is transferred to the driven machine. The behavior of elastic shafts with different stiffness in the transmission system is studied. Moreover, the steady state and dynamic behavior of the system considering the influence of the elastic shafts and vibration analysis were investigated using simulation. A model algorithm for system simulation was developed using the MATLAB/SIMULINK software. Characteristic simulation results are presented and are expressed in terms of speed and torque response. Considering the resonance frequency analysis and simulation results, mechanical design guidelines can be given for the most significant drive components in order to avoid torsional oscillation resonance phenomena and minimize torsional oscillations of the drive system.

This paper presents and verifies a new mathematical model to explain the dynamic behavior of characteristic gases in the oil-cellulose insulation of high voltage devices like power transformers. The model is based on the diffusion process. Parameters of the model are already quantified from experiments and presented in previous publications. The mathematical model and assumptions are presented here. The model solution is obtained analytically and gas concentration change inside the paper insulation as a function of time is simulated. The results are converted to the concentration change in the oil using the principle of conservation of mass and validated with experimental measurements. The presented model can be used to reduce the error of dissolved gas analysis due to the migration of characteristic gases inside a healthy power transformer.

Dirty-paper coding makes an analogy to the problem of writing on dirty paper, where the reader cannot nominally distinguish dirt from ink. There are many scenarios where this result may be applied. In the field of information hiding (or watermarking), theoretical bounds as well as practical watermarking schemes have been found. Another important application of dirty-paper coding is for a multiuser channel wherein a multiple-antenna transmitter is communicating with multiple users.

A printed lateral resistive fuse-type write-once-read-many (WORM) memory on paper substrate is demonstrated. The memory writing process is based on breaking of a silver nanoparticle conductor. Low-voltage and low-current writability demonstrated with printed batteries are enabled by a μm2-range cross-sectional bit area that are achieved by super-fine inkjet technology. Supported by the statistical distribution of the writing times, the bit writing process is attributed to electromigration of silver and the required current density for fusing is found to be 34 mA/μm2. The results show an improvement in memory retention time when compared with structurally similar printed antifuse-type WORM memories

This article describes the events that occurred during the transition from PILC to XLPE-insulated cables in the United States. This personal account is from a utility perspective as experienced by Pacific Gas and Electric Company engineers with emphasis on the effect of water treeing.

The article "A 4-GHz Continuous-Time Δ-ΣADC with 70-dB DR and -74 dBFS THD in 125-MHz BW" by Muhammed Bolatkale, Lucien J. Breems, Robert Rutten, and Kofi A.A. Makinwa, published in IEEE Journal of Solid-State Circuits (JSSC), vol. 46, no. 12, pp. 2857-2868, Dec. 2011, was declared best of all in JSSC 2011. The authors' novel approach modifies loop filter architecture to deal with the parasitics and excess delay of the large comparator array in the 4-GHz multibit quantizer. Their five-times improvement in bandwidth compared to state-of-theart CMOS delta-sigma modulators enlarges the application domain of these ADCs, enabling them to compete with high speed architectures like pipeline ADCs. A detailed review of the article is provided.

In the third quarter issue of the EMC Magazine my good friend Don Sweeney wrote an article on what he did with our colleague Ed Bronaugh's files and the time it took him to do it. He had an excellent ?coding? system with colored tags to indicate everything from shredding to giving to our EMC Society History Committee for further reviewing. What this illustrates is that we need to keep some of the key work of our EMC Society technical leaders so that others can make use of that information. To do this there needs to be an accessible repository of what is in our EMC discipline which of course depends on the eyes of the beholder. Archiving is one way to preserve history of key activities or organizations, explain what made the difference in the past to apply in the future, provide a resource for researchers or to remember those involved in the work.

The four papers in this special section were presented at the joint 2015 Genome Informatics Workshop/International Conference on Bioinformatics GIW/InCoB.

Knowledge about moisture content in oil impregnated paper insulation is essential when estimating remaining lifetime of power transformers. Direct evaluation of moisture content is rarely possible due to inaccessibility of the internal insulation system in transformers. Therefore, various indirect estimation techniques are utilized. Frequency domain spectroscopy (FDS) measurements of transformer insulation belong to this group. To perform high quality interpretation of results of FDS measurements a good knowledge on dielectric responses in oil impregnated pressboard and paper is required, especially as it refers to their variation with water content and temperature. The aim of this paper is to provide an open access to the frequency domain spectra of oil impregnated paper and pressboard samples, which can then be used in modeling of the results of diagnostic measurements in power transformers.

Partial discharge (PD) inception and breakdown (BD) characteristics of liquid nitrogen (LN2)/polypropylene (PP) laminated paper composite insulation system for high temperature superconducting (HTS) cables are presented. In this paper, we measured PD inception characteristics under lightning impulse and AC voltage applications by electrical, optical and acoustic methods. The impulse PD inception characteristics were compared with those under AC voltage application, and the PD generation mechanisms are discussed. Experimental results reveal that PD detection sensitivity under lightning impulse voltage application is as small as 6 pC. PD inception at the lower stress was verified to be generated not only in the butt gaps but also in micro gaps between PP laminated paper layers under both lightning impulse and AC voltage applications. After PD inception, PD activity could be developed in the butt gaps at the higher stress, finally leading to BD

International audience; The huge potential of ultra wide band impulse radio (UWB IR) with multiple access was initially evaluated using the standard Gaussian approximation which assumed that multi user interference could be approximated as classical Gaussian noise. Later the standard Gaussian approximation has been proved to be invalid in several cases. Thus the performance of the classical UWB IR correlation receiver dramatically reduces. We show in this paper how the non Gaussianity of the multi user interference can be exploited, turning the non Gaussianity into an advantage, increasing the performance with respect to the Gaussian interference case which was supposed to be too optimistic until now.

Direct-sequence code-division multiple-access (DSCDMA) cellular systems, such as wideband CDMA (WCDMA), are limited in performance by interference. Linear equalization, such as generalized Rake (G-Rake) receivers and transversal chip equalizers, can theoretically provide significant gains in performance by suppressing interference. In this paper, an adaptive G-Rake receiver is developed, employing practical algorithms for finger placement and weight computation. Finger placement is determined by selecting delays from a candidate set using a "maximal-weight" criterion. Weight computation includes estimation of an impairment covariance matrix using a parametric approach. While described in the context of the downlink, these algorithms can be used in the uplink as well. Both single-antenna and dual-antenna receivers are considered. Link and system performance are evaluated for the downlink, showing significant gains in high-rate coverage.

We consider a fading version of the dirty-paper problem, as proposed by Grover and Sahai. In this formulation, the various signals involved are complex-valued, and the interference (known only to the transmitter) is multiplied by a random complex-valued coefficient, whose phase is known only to the receiver. We focus on a compound channel formulation, and seek to maximize the worst-case performance. We present an achievable strategy modeled on the lattice-based approach of Erez, Shamai and Zamir and propose heuristic methods to optimize its parameters. We also derive an upper bound on the maximum achievable transmission rates. Our bounds are shown to be tight in some settings, yielding a complete characterization of capacity. We also provide simulation results, indicating the practical effectiveness of our approaches.

Previous research on sensor network security mainly considers homogeneous sensor networks, where all sensor nodes have the same capabilities. Research has shown that homogeneous ad hoc networks have poor performance and scalability. The many-to-one traffic pattern dominates in sensor networks, and hence a sensor may only communicate with a small portion of its neighbors. Key management is a fundamental security operation. Most existing key management schemes try to establish shared keys for all pairs of neighbor sensors, no matter whether these nodes communicate with each other or not, and this causes large overhead. In this paper, we adopt a Heterogeneous Sensor Network (HSN) model for better performance and security. We propose a novel routing-driven key management scheme, which only establishes shared keys for neighbor sensors that communicate with each other. We utilize Elliptic Curve Cryptography in the design of an efficient key management scheme for sensor nodes. The performance evaluation and security analysis show that our key management scheme can provide better security with significant reductions on communication overhead, storage space and energy consumption than other key management schemes.

An optical sensor for real-time measurement of lignin content in moving paper sheets is described in this paper. The sensor is useful for high-speed automated sorting of papers according to lignin content in a mixed-waste stream for efficient recycling. The sensor measures lignin fluorescence when excited in the visible region. Results indicate that when paper surfaces are excited with a laser source (532 nm), the lignin fluorescence spectrum shows a peak near 650 nm. Measurement of this peak intensity from paper samples is a measure of lignin content and correlates linearly with the standard chemical method for lignin determination (Klasson lignin content). Newsprint samples, typically containing high lignin, produce high intensity, while ledger printing and writing grades with low lignin content produce low-fluorescence intensity. The proposed sensor configuration is discussed and results from a systematic study of variables, namely, text printed on surface, homogeneous dyed in color, printed color patches, paper thickness, sensor configuration parameters such as excitation source intensity, and distance from sample surface are reported. In dynamic tests on a simulated conveyor operating at realistic speeds, the sensor is able to reliably measure fluorescence intensities on unprinted samples without ambiguity and identify high and low lignin-containing samples.

Partial discharge (PD) inception characteristics of liquid nitrogen (LN_2)/ polypropylene (PP) laminated paper composite insulation system for high temparature superconducting (HTS) cables were investigated in terms of the volume effect and the V-t characteristics. The electrical and optional measurements of PD inception characteristics showed that initial PD could be generated between PP laminated paper layers, as well as in a butt gap. Using a parameter called satistically stressed liquid volume (SSLV) based on the discharge probability in both butt gaps and LN_2 filled thin layers between PP laminated papers, we could systematically analyze and evaluate the volume effect on PD inception stress (PDIE). Furthermore, experimental results revealed that n values of V-t characteristics at PD inception were as high as 80-110. On the other hand, the lower n values obtained at breakdown were interpreted by the intensified PD development in thermal bubbles generated after the PD inception.

Low-voltage flexible dual-gate indium-tin-oxide-based thin-film transistors (TFTs) are self-assembled on SiO2-covered paper substrates by one shadow mask diffraction method. Solution-processed chitosan gate dielectric films have a large gate specific capacitance (5.8 μF/cm2) due to the electric-double-layer effect. The subthreshold swing, drain-current on/off ratio, and field-effect mobility are estimated to be 80 mV/dec, 4 ×106, and 9.3 cm2/V·s, respectively. Low-voltage operation mechanism and threshold voltage modulation of such dual-gate paper TFTs are investigated.

The detection of Partial Discharges (PD) is a reliable technique to analyze the status of electrical insulation in power transformers. Phase resolved partial discharge patterns are being complemented with high frequency pulse waveform analysis, in order to identify discharge sources. In addition to this, acoustic techniques are being implemented trying to locate PD sites in large power transformers. In this work, an inductive loop sensor will be used to identify two different PD sources by means of the energy distribution of the detected waveforms. Additionally, these PD sources will be located by means of acoustic measurements with an electrical reference, through the analysis of the acoustic activity detected for each sensor individually.

Present and future condition-based maintenance methods and preventive maintenance strategies will require knowledge of the present condition of the equipment. For cable networks in gen eral, and for PILC cables in particular, our understanding of the physical phenomena that occur inside cable insulation systems during operation, and their influence on the remaining service lifetime, is still fragmentary. The ICAAS system was developed primarily to facilitate an artificial aging program on MV PILC cables, based on tan δ, return voltage, and PD measurements. An extensive database was built up over a period of two years. Further results will be presented in due course. It should be noted that the ICAAS is fairly freely configu rable so that, with a little effort, it could be applied to other cable types, cable garnitures, sleeves, and terminations. It could also be used to study specific cable defects introduced during manu facture or for the general verification of production quality.

We propose and analyze in this paper two new adaptive power controlled minimum selection generalized selection combining (MS-GSC) diversity schemes. The key idea behind these two schemes is to request the transmitter to vary its power level during very adverse channel conditions in order to communicate with the minimum required quality of service. For each scheme, four power control variants accounting for practical implementation constraints including discrete power levels and transmitter gain saturation are proposed and studied. Selected numerical examples, show that ideal continuous power control lowers the average bit error rate of MS-GSC and makes it always meet the specified target quality of service at the expense of an increase in the transmitter gain. Additional numerical examples, show that the power control variants that take into account practical implementation constraints conserve the main features of the ideal continuous power algorithm.

This paper proposes and evaluates two robust sheet tension estimation algorithms based on unwind and rewind variables, respectively. The proper sheet tension estimation is guaranteed by a continuous monitoring of the differences between the actual estimated values and the values predicted from the last calibration of the estimation parameters. The evaluation was performed with the aid of a developed winder emulator that allowed the off-line testing in a real-time field environment, including the inertial setting of the estimation constants, and evaluation of both 4 and 6 shipping-roll cycles. The sheet tension estimation results confirm the precise and stable operation of the proposed robust estimation algorithms, in estimation tests conducted with signals from a winder model, and with tests involving actual field signals from an operational winder.

In this paper, we present a framework for studying folding problems from a motion-planning perspective. The version of the motion-planning problem we consider is that of determining a sequence of motions to transform some configuration of a foldable object (the start) into another configuration (the goal). Modeling foldable objects as tree-like multilink objects allows us to apply motion-planning techniques for articulated objects with many degrees of freedom (many links) to folding problems. An important feature of this approach is that it not only allows us to study foldability questions, such as, can one object be folded (or unfolded) into another object, but it also provides us with another tool for investigating the dynamic folding process itself. The framework proposed here has application to traditional motion-planning areas such as automation and animation, to paper-folding problems studied in computational geometry, and to computational biology problems such as protein folding. Preliminary experimental results with paper folding and the folding of small proteins (approximately 60 residues) are quite encouraging.

Moisture and ageing strongly influence the dielectric properties of oil/paper insulation system of power transformer. Moisture measurement in oil sample generally gives inconclusive information since oil/paper moisture equilibrium is temperature dependent and takes a long time to be in equilibrium. Direct moisture measurement of paper sample is not practicable for in-service transformers. The measurement and evaluation of the "dielectric response" and conductivity is one possible way of diagnosing a transformer insulation condition. In a recent research project, polarization and depolarization current measurement has been used for assessing the condition of oil/paper insulation. The polarization and depolarization current (PDC) analysis is a nondestructive dielectric testing method for determining the conductivity and moisture content of insulation materials in a transformer. On the basis of this analysis it is possible to take further actions like oil-refurbishment, drying or replacement of the winding of the transformer. This paper presents a description of the PDC technique with the physical and mathematical background and some results of PDC measurements on several transformers. Analyses and interpretation of the field test data are also presented in this paper.

The IEEE International Conference on Plasma Science (ICOPS) is an annual meeting of plasma physics and chemistry researchers with emphasis on various applications of plasma science and technology. This meeting is sponsored by the Plasma Science and Applications Committee of the IEEE Nuclear and Plasma Science Society.

What, if anything, will be the role of publishers in a world in which books are formatted by their authors, distributed electronically, and read online? The success of e-books has spawned a boom in self-publishing, with the possibility that just as musicians now depend not on recording contracts but self-promotion for concert revenues, authors will depend on direct sales to readers rather than having their books packaged by publishers. Readers can expect more choice and lower prices, but writers will face a continued struggle.

Device placement is a fundamental factor in determining the coverage, connectivity, cost and lifetime of a wireless sensor network (WSN). In this paper, we explore the problem of relay node placement in heterogeneous WSN. We formulate a generalized node placement optimization problem aimed at minimizing the network cost with constraints on lifetime and connectivity. Depending on the constraints, two representative scenarios of this problem are described. We characterize the first problem, where relay nodes are not energy constrained, as a minimum set covering problem. We further consider a more challenging scenario, where all nodes are energy limited. As an optimal solution to this problem is difficult to obtain, a two-phase approach is proposed, in which locally optimal design decisions are taken. The placement of the first phase relay nodes (FPRN), which are directly connected to sensor nodes (SN), is modeled as a minimum set covering problem. To ensure the relaying of the traffic from the FPRN to the base station, three heuristic schemes are proposed to place the second phase relay nodes (SPRN). Furthermore, a lower bound on the minimum number of SPRN required for connectivity is provided. The efficiency of our proposals is investigated by numerical examples.

To commemorate the 50th anniversary of IEEE Journal of Solid-State Circuits, the IEEE Solid-State Circuits Society has put together a list of the top-cited papers from each decade since the journal?s beginning in 1966. To read the papers in their entirety, please visit the IEEE Solid-State Circuits Society website.

Each year, the IEEE Journal of Solid-State Circuits Best Paper Award is presented to the authors of a paper that is considered by the journal's editorial staff and reviewers to be the most exceptional paper published in the preceding full-year volume. The award is based on accuracy, originality, technical content, and the quality of the article. The award is presented each year at the International Solid-State Circuits Conference.

When faced with the tasks of reading and writing a complex technical paper, many nonnative scientists and engineers who have a solid background in English grammar and vocabulary lack an adequate knowledge of commonly used structural patterns at the discourse level. In this paper, we propose a novel computer software tool that can assist these people in the understanding and construction of technical papers, by automatically identifying the structure of writing in different fields and disciplines. The system is tested using research article abstracts and is shown to be a fast, accurate, and useful aid in the reading and writing process.