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Cable capacity is one of the important parameters of cable engineering design and operation, and its value is obtained under the condition of constant load current. The load current of a power system usually varies periodically during actual operation. In order to study the transmission capacity of cable under periodic load, a numerical calculation program for transient temperature field of cable is compiled based on the finite difference method, and the temperature rise test of a direct buried cable is carried out with a large current. The results of the test are in agreement with the numerical results. This transient calculation program is used to calculate the temperature rise of the cable core under 24h periodic load and determine the periodic load carrying capacity, and an analytical calculation formula for calculating the periodic load carrying capacity of a direct buried cable is given.

We have built and implemented a time-resolved ellipsometry diagnostic for dynamic material properties experiments at Sandia National Laboratories. This diagnostic measures the complex dielectric value of a sample experiencing dynamic compression, with a time resolution of a few nanoseconds. We show and discuss the dynamic ellipsometry measurements taken from shock loading experiments on a gas gun. This work is relevant to geophysical materials at high pressure-temperature conditions.

Humanity is facing an increasing number of highly virulent and communicable diseases such as avian influenza. Researchers believe that avian influenza has potential to evolve into one of the deadliest pandemics. Combating these diseases requires in-depth knowledge of their epidemiology. An effective methodology for discovering epidemiological knowledge is to utilize a descriptive, evolutionary, ecological model and use bio-simulations to study and analyze it. These types of bio-simulations fall under the category of computational evolutionary methods because the individual entities participating in the simulation are permitted to evolve in a natural manner by reacting to changes in the simulated ecosystem. This work describes the application of the aforementioned methodology to discover epidemiological knowledge about avian influenza using a novel eco-modeling and bio-simulation environment called SEARUMS. The mathematical principles underlying SEARUMS, its design, and the procedure for using SEARUMS are discussed. The bio-simulations and multi-faceted case studies conducted using SEARUMS elucidate its ability to pinpoint timelines, epicenters, and socio-economic impacts of avian influenza. This knowledge is invaluable for proactive deployment of countermeasures in order to minimize negative socioeconomic impacts, combat the disease, and avert a pandemic.

An analytic model developed by Ao et al.[1] describes the interaction of turbulence with a thin MHD shock. The interaction is governed by a modified Burgers’ equation. In this paper, we solve the modified Burgers’ equation numerically for arbitrary oblique MHD shocks. Starting with the classical ideal MHD Rankine‐Hugoniot condition, we introduce a perturbed upstream and demonstrate the evolution of the oblique MHD shock structure. We also show the dependence of shock‐turbulence interaction on different oblique angles. Our results show that turbulence plays a very important role in modifying shock front structure for oblique MHD shocks. When turbulence is modifying shock front structure, the oblique angle is another important factor. Larger oblique angle turns out to be able to creat a wider smoothed ramp in some regions and higher compression ratio in other regions.

With recent advance of the genotyping single nucleotide polymorphisms (SNPs) in mass scale of high density in a candidate region of the human genome, the linkage disequilibrium analysis can offer a much higher resolution of the biological samples than the traditional linkage maps. We have formulated this LD mapping problem as a constrained unidimensional scaling problem. Our method, which is directly based on the measurement of LD among SNPs, is non‐parametric. Therefore it is different from LD maps derived from the given Malecot model. We have formulated with the quadratic programming approach for solving this constrained unidimensional scaling problem. Different from the classical metric unidimensional scaling problem, the constrained problem is not an NP‐hard combinatorial problem. The optimal solution is determined by using the quadratic programming solver. Nevertheless, because of the large requirement for memory during the running time that may cause the out of memory problems, and the high computat...

Ultrafast compression provides unique insights into material behavior at extreme conditions. Starting from ambient conditions, compressed samples can reach pressures of 1-100+ GPa, accompanied by temperature changes of 102-105 K, within 10-100 ns. Dynamic temperature measurements of these states provide a wealth of thermodynamic information but are challenging in single-event experiments. Optical pyrometry can be used in some situations but becomes infeasible below 1000 K. Instead of inferring temperature based on light emitted by a sample, we propose to measure dynamic temperature states based on light reflected from a sample. As an active measurement, reflectance thermometry yields measurable optical signals at any temperature, potentially with nanosecond time resolution.

We calculate the power spectra densities of magnetic field fluctuations associated with interplanetary shock waves at 1AU, utilizing in-situ magnetic field measurements from spacecraft ACE and Wind. We derive related quantities both upstream and downstream of a shock as a function of time/distance away from the shock passage. We present results for a few events that exhibit clear upstream enhanced wave activity. We show that mostly they are of Alfvenic nature and confined within certain distance upstream. We also present a preliminary analysis of turbulence-particle interaction based on spectral analysis results. Implications of such analysis to turbulence transport models are also discussed.

We compare the efficiency of proton acceleration at oblique strong CME shocks at radial heliocentric distances from 0.13 to 2.5 AU. We use the PATH code to obtain the diffusion coefficients and maximum achievable particle energies at shocks with 15°, 45° and 75° shock angles. In computing the maximum energy, we use the total diffusion coefficient which is a function of the parallel diffusion coefficient and the perpendicular diffusion coefficient. The parallel diffusion coefficient is calculated from the wave intensity of Alfven waves generated by streaming protons in the shock vicinity [1, 2]. The perpendicular diffusion is described in the NLGC approach and depends on the parallel diffusion coefficient and pre-existing turbulence in the solar wind [3, 4, 6]. It is shown that efficiency of particle acceleration at a fast CME-driven shock depends on the shock angle, injection energy and radial heliocentric distance. Quasi-perpendicular strong shocks are more efficient in accelerating higher-energy seed particles, especially at larger heliocentric distances and close to the Sun. By contrast, quasi-parallel strong shocks can accelerate particles more efficiently at distances about 1 AU.

A set of one-dimensional two-fluid plus Maxwell's equations are solved numerically with very high spatial and temporal resolutions. The simulation captures the formation of the cross-shock potential (CSP) on electron Debye and plasma frequency scales. Test particles are launched towards the shock and their trajectories across the cross-shock electric and magnetic fields indicate the importance of shock surfing acceleration (SSA) at the quasi-perpendicular shock.

We examine the Diffusive Shock Acceleration (DSA) mechanism in large SEP events. We first discuss the observational constraints of the underlying particle acceleration mechanism in GLE events. We then briefly review the standard DSA mechanism and follow that by a discussion of the injection efficiency as well as an estimate of the maximum particle energy at an oblique shock.

It is now widely believed that, in large SEP events, particles are accelerated through the Diffusive Shock Acceleration (DSA) mechanism. In this paper we discuss a few factors that control the maximum energy of particles in large SEP events. Using the NLGC theory, we first examine the effect of shock geometry on the attainable maximum particle energy. The injection energy is assumed to have a simple θBN dependence. We also discuss the effect of seed population on the acceleration. A recent survey has shown that in a large fraction of large SEP events, there existed preceding CMEs; and in those that no preceding CMEs exist, the maximum intensities correlate with pre-event low energy (of ACE/ULEIS energies) particle intensities at 1 AU. We argue that the seed population is important in these events.

We examine ion-acoustic solitons in two-fluid plasmas without the usual simplification of setting electron mass to zero. Assuming one-dimensional, electrostatic and cold protons, the system is treated analytically, resulting in an integral form solution. We present numerical calculations which resolve the ion-acoustic solitary wave signatures. Also, we consider the conditions for which ion-acoustic solitons may exist. The existence conditions set up a Mach number threshold. Our result shows that the Mach number threshold depends on the electron-to-proton mass ratio and the electron adiabatic index; for a special adiabatic index γ = 2, the condition reduces to a cubic equation.

We calculate the power spectral densities of magnetic field fluctuations associated with interplanetary shock waves, utilizing in-situ magnetic field measurements from spacecraft ACE and Wind at 1AU. We derive related quantities both upstream and downstream of a shock as a function of time/distance away from the shock passage. We present results for a few events that exhibit clear upstream enhanced wave activity. We show that mostly they are of Alfvenic nature and confined within certain distance upstream. We also present a preliminary observational analysis of turbulence-shock interaction based on perturbation analysis.

Gelled materials combine mechanical properties of liquids and solids. Knowing the rheological behavior of these systems is essential in many technological areas. The present paper presents a study on fluid properties of silica gels and HPC water systems containing aluminum oxide nanoparticles. Viscosity measurements for silica‐hydrocarbon gels showed qualitatively evidence of thixotropicity in the fluid with no viscosity recovery. Steady state and small amplitude oscillatory stress tests were performed for HPC water systems with the addition of metal nanoparticles, showing the particles effect on the viscosity and viscoelasticity of the fluid. No time dependence or thixotropy was observed for these samples.

Complex numbers play important role in various engineering applications. To represent these numbers efficiently for storage and manipulation, a (−1+j)‐base complex binary number system (CBNS) has been proposed in the literature. In this paper, designs of nibble‐size arithmetic circuits (adder, subtractor, multiplier, divider) have been presented. These circuits can be incorporated within von Neumann and associative dataflow processors to achieve higher performance in both sequential and parallel computing paradigms.

This work presents a derivation of PWM DC-DC hybrid converters by combining traditional converters with the Cockcroft–Walton voltage multiplier, the voltage multiplier of each converter is driven with the same transistor of the basic topology; this fact makes the structure of the new converters very simple and provides high-voltage gain. The traditional topologies discussed are the boost, buck-boost, Cuk and SEPIC. They main features of the discussed family are: (i) high-voltage gain without using extreme duty cycles or transformers, which allow high switching frequency and (ii) low voltage stress in switching devices, along with modular structures, and more output levels can be added without modifying the main circuit, which is highly desirable in some applications such as renewable energy generation systems. It is shown how a multiplier converter can become a generalized topology and how some of the traditional converters and several state-of-the-art converters can be derived from the generalized topologies and vice-versa. All the discussed converters were simulated, additionally experimental results are provided with an interleaved multiplier converter.

This research paper presents a new concept of using a single tool to associate syntax of various programming languages, algorithms and basic coding techniques. A simple framework has been programmed in Python that helps students learn skills to develop algorithms, and implement them in various programming languages. The tool provides an innovative and a unified graphical user interface for development of multimedia objects, educational games and applications. It also aids collaborative learning amongst students and teachers through an integrated mechanism based on Remote Procedure Calls. The paper also elucidates an innovative method for code generation to enable students to learn the basics of programming languages using drag‐n‐drop methods for image objects.

Mapping algorithm which means which core should be linked to which router is one of the key issues in the design flow of network‐on‐chip. To achieve an application‐specific NoC design procedure that minimizes the communication cost and improves the fault tolerant property, first a heuristic mapping algorithm that produces a set of different mappings in a reasonable time is presented. This algorithm allows the designers to identify the set of most promising solutions in a large design space, which has low communication costs while yielding optimum communication costs in some cases. Another evaluated parameter, vulnerability index, is then considered as a principle of estimating the fault‐tolerance property in all produced mappings. Finally, in order to yield a mapping which considers trade‐offs between these two parameters, a linear function is defined and introduced. It is also observed that more flexibility to prioritize solutions within the design space is possible by adjusting a set of if‐then rules in...

There are already‐established methods for investigating biological signals such as rhythmic heartbeats. We used detrended fluctuation analysis (DFA), originally developed by Peng et al. (1995) to check power‐law characteristics, because the method can quantify the heart condition numerically. In this article, we studied the heartbeat of sleeping subjects. Our purpose was to test whether DFA is useful to evaluate the subject’s wellness of both during being awake and sleeping. This is a challenge to measure sleep without complex/expensive machine, an electro encephalography (EEG). We conducted electrophysiological recording to measure heartbeats during sleep using electrocardiograph with three‐leads, one ground electrode and two active electrodes attached to chest. For good recording, a stable baseline must be maintained even when subjects move their body. We needed a tool to ensure long‐term steady recording. We thus invented a new electric‐circuit designed to produce this desired result. This gadget allowed us to perform heartbeat recording without any drifting baseline. We then were able to detect 100% of heartbeat peaks over the entire period of sleep. Here, we show a case study as empirical evidence that DFA is useful numerical method for quantifying sleep by using the scaling exponents.

Industrial grade ethyl acetate is available with minimum purity of 85.0%. It is mostly produced by an ethanol esterification in a distillation process on both batch and continuous modes. However, researches on high purity production with short operating time are rarely achieved. Therefore, the objective in this work is to study an approach to produce ethyl acetate of 90.0% by 8 hours using a batch reactive distillation column. Based on open‐loop simulations, the distillation with constant reflux ratio cannot achieve the product specification. Thus, the dynamic optimization strategy is proposed to handle this problem. For the process safety—preventing the dried column and fractured, a minimum reflux ratio must be determined in advance and then an optimal reflux profile is calculated to achieve optimal product yield. Simulation results show that the industrial grade ethyl acetate can be produced by the dynamic optimization programming with two or more time intervals. Besides, the increasing of time intervals can produce more distillate product.Industrial grade ethyl acetate is available with minimum purity of 85.0%. It is mostly produced by an ethanol esterification in a distillation process on both batch and continuous modes. However, researches on high purity production with short operating time are rarely achieved. Therefore, the objective in this work is to study an approach to produce ethyl acetate of 90.0% by 8 hours using a batch reactive distillation column. Based on open‐loop simulations, the distillation with constant reflux ratio cannot achieve the product specification. Thus, the dynamic optimization strategy is proposed to handle this problem. For the process safety—preventing the dried column and fractured, a minimum reflux ratio must be determined in advance and then an optimal reflux profile is calculated to achieve optimal product yield. Simulation results show that the industrial grade ethyl acetate can be produced by the dynamic optimization programming with two or more time intervals. Besides, the increasing of time interval...

The direct photolysis of 2‐chlorophenol (2‐CP), 4‐chlorophenol (4‐CP) and 2,4‐dichlorophenol (2,4‐DCP) in model aqueous solution was studied using UV XeBr (282 nm) and KrCl (222 nm) excilamps. The highest pseudo‐first order rate constants and quantum yields were found for molecular form of 4‐CP (at pH 2 and 5.7) and anionic forms of 2‐CP and 2,4‐DCP (at pH 11) when irradiated by XeBr excilamp. The maximum removal efficiency of molecular form of 2‐CP and 2,4‐DCP with the lowest UV dose of absorbed energy was observed using KrCl excilamp. On the contrary, the XeBr excilamp required the lowest dose (∼2 J⋅cm−2) for complete degradation of molecular 4‐CP and anionic 2‐CP. The highest removal efficiency of anionic form of 4‐CP (65%) was achieved when using KrCl excilamp.

Separation processes is largely used in petroleum refining and alcohol industries. Distillation columns consume a huge amount of energy in industrial process. Therefore, the concept of Heat‐Integrated Distillation Column (HIDiC) was studied using simulation techniques in order to overcome this drawback. In this configuration the column is composed for two concentric sections called rectifying and stripping. The heat transfer is conducted from the rectifying section (which works at higher pressure and temperature) to the stripping section (which works at lower pressure and temperature) using the heat present in the process and decreasing the energy charge required by the reboiler. The HIDiC column offers great potential to reduce energy consumption compared to conventional columns. However, the complexity of the internal configuration requires the development of rigorous works that enable a better understanding of the column operation. For this reason, techniques of simulation were used through of computational software. The current work presents a heat transfer study in a concentric stage of a HIDiC column. The results obtained by Aspen Plus and CFD simulation showed the internal heat transfer in a concentric tray as a promissory configuration in order to decrease energy consumption in distillation processes.

Geriatric patients with dementia and hypertension (DAH) suffer both physically and financially. The needs of these patients mainly include improving the quality of daily living and reducing the cost of long‐term care. Traditional treatment approaches are strained to meet these needs. The goal of the paper is to design an innovative system to provide cost‐effective quality treatments for geriatric patients with DAH by collecting and analyzing the multi‐dimensional personal information, such as observations in daily living (ODL) from a non‐clinical environment. The proposed ODLs in paper include activities, cleanliness, blood pressure, medication compliance and mood changes. To complete the system design, an incremental user‐centered strategy is exploited to assemble needs of patients, caregivers, and clinicians. A service‐oriented architecture (SOA) is employed to make full use of existing devices, software systems, and platforms. This health‐related knowledge can be interpreted and utilized to help patients with DAH remain in their homes safely and improve their life quality while reducing medical expenditures.

Learning how to express a matrix using a keyboard inputs requires a lot of time for most of college students. Therefore, for a problem based learning system for linear algebra to be accessible for college students, it is inevitable to develop a simple method for expressing matrices. Studying the two most widely used input methods for expressing matrices, a simpler input method for expressing matrices is obtained. Furthermore, using this input method and educator’s knowledge structure as a concept map, a problem based learning system for linear algebra which is capable of assessing students’ knowledge structure and skill is developed.

The flow of particles suspended in fluids and transported through different geometries is a process with numerous industrial applications ranging from chemical processing to bio‐analytic separation. A filtrate particle flowing through the channel may be trapped by the geometric constraint or other adhesive mechanisms. Realistic filters have randomly‐interconnected channel space with a complex flow path. However, in micro‐fluidic systems, channel space may resemble two‐dimensional tessellation. Here we adopt the network flow concept to analyze two‐dimensional microfilters and study the filter efficiency (effective conductibility) and the clogging time i.e. the time until a filter becomes clogged due to the trapping of suspended particles.

It has been reported that Internet Protocol (IP) packet traffic exhibits self‐similarity or long range dependence (LRD) and causes the degradation of switch performance. Therefore, it is crucial for an appropriate buffer design of a switch. In this paper, we investigate delay behavior of the switch under self‐similar variable length packet traffic by modeling it as MMPP/M/1/K queueing system wherein MMPP (Markov‐Modulated Poisson Process) is fitted by equating the variance of MMPP and that of self‐similar traffic. MMPP model is already validated one to emulate the self‐similar characteristics. Voids that will occur because of variability in packet length is considered. We investigate mean delay against system parameters, traffic parameters and fitting parameters. Numerical results show that analysis presented in this paper is useful in dimensioning the switch.

Based on concepts of shape selectivity and hydrogen spillover, a zeolite with encapsulated Pt was prepared by in‐situ synthesis and used to make a sulfur‐resistant noble metal catalyst. The prepared Encapsulated Pt Zeolite zeolite was of the sodalite type, whose pore openings allow H2 to enter but not H2S. Chemisorption with H2/CO was conducted to verify the most of Pt atoms distribution in the cage of Pt/SOD prepared by in‐situ hydrothermal method. The catalyst was tested for hydrogenation activity using a real feed oil with high contents of multi‐ring aromatics and sulfur. The catalyst showed reasonable hydrogenation activity even at high levels of sulfur poison.

Jitter is a matter of great concern for high‐speed digital designers because of its ability to degrade the overall system performance. Designing a low‐jitter and wide‐band phase locked loop (PLL) system is of practical importance because of its application in high speed digital systems. This paper experimentally investigates a low‐jitter and wide‐band dual cascaded PLL system using a single crystal oscillator. The first PLL used in the system employs a voltage‐controlled crystal oscillator (VCXO) to eliminate the input jitter whereas the second PLL provides wide bandwidth. Field Programmable Gate Array (FPGA) is used to generate a jittered clock source which is then passed through the proposed system to achieve wide‐band and low‐jitter signal. Experimental results are presented to validate the proposed technique for different carrier frequencies.

Longest‐path routing problems, which can arise in the design of high‐performance printed circuit boards (PCBs), have been proven to be NP‐hard. In this article, we propose a constraint programming (CP) formulation and a mixed integer linear programming (MILP) formulation to gridded longest‐path routing problems; each of which may contain obstacles. After a longest‐path routing problem has been transformed into a CP problem, a CP solver can be used to find optimal solutions. On the other hand, parallel MILP solvers can be used to find optimal solutions after the longest‐path routing problem has been transformed into an MILP problem. Also, suboptimal solutions can be generated in exchange for reduced execution time. The proposed formulation methods can also be used to solve shortest‐path routing problems. Experimental results show that more than 3,700x speed‐up can be achieved by using a parallel MILP solver with 16 threads in solving formulated longest‐path routing problems. The execution time can be further reduced if a computer containing more processer cores is available.

The significance of optimization of gate–source/drain extension region (also known as a non‐classical underlap design) in double gate (DG) silicon‐on‐insulator (SOI) FETs to improve the linearity performance of a low power folded cascode operational transconductance amplifier (OTA) is described. Based on a new figure‐of‐merit (FoM) involving AV, linearity, unity gain bandwidth fT and dc power consumption PDC, this article presents guideline for optimum design for underlap spacer s and film thickness Tsi to maximize the performance of OTA. It has been shown that FoM exhibited by an underlap DG MOSFET OTA gives significantly higher value (≅9) compared to a conventional single gate bulk MOSFET OTA. This is due to a combination of both higher fT, and higher gain AV for the same linearity at low power consumption of 360 μW. With gate length scaling, FoM continues to improve, primarily due to higher value of fT. A scaled bulk MOSFET OTA exhibits similar but much smaller enhancement in trend for FoM.

The resources for electrical energy are depleting and hence the gap between the supply and the demand is continuously increasing. Under such circumstances, the option left is optimal utilization of available energy resources. The main objective of this chapter is to discuss about the Peak load management and overcome the problems associated with it in processing industries such as Milk industry with the help of DSM techniques. The chapter presents a generalized mathematical model for minimizing the total operating cost of the industry subject to the constraints. The work presented in this chapter also deals with the results of application of Neural Network, Fuzzy Logic and Demand Side Management (DSM) techniques applied to a medium scale milk industrial consumer in India to achieve the improvement in load factor, reduction in Maximum Demand (MD) and also the consumer gets saving in the energy bill.

Two surveys of college students were conducted to study the students’ perceptions and knowledge of computer science as a profession and as a career. Ignorance of the field was consistently observed in both samples. Students with an aptitude for computing tend to blame their high schools, media, and society for their lack of knowledge. These findings suggest that high school students need to be provided with a more balanced perspective on computing.

Implicit Media Knowledge aims to provide relevant information related to visual media without effort. It is based on the analysis of media usage from several users (e.g. a community). Algorithms based on clustering methods that extract relevant information (e.g. tags, taxonomy trees) related to a media from its usage are detailed. To validate our new approach, we propose to apply our concept and algorithms on a specific media use such as the analysis of how multiple users organize their media files. Significant results of two experiments will be highlighted. Perspectives of our work will be finally presented.

The objective of this study is to improve the efficiency of the flow‐wrap packaging process in soap industry through the reduction of defectives. At the 95% confidence level, with the regression analysis, the sealing temperature, temperatures of upper and lower crimper are found to be the significant factors for the flow‐wrap process with respect to the number/percentage of defectives. Twenty seven experiments have been designed and performed according to three levels of each controllable factor. With the general linear model (GLM), the suggested values for the sealing temperature, temperatures of upper and lower crimpers are 185, 85 and 85° C, respectively while the response surface method (RSM) provides the optimal process conditions at 186, 89 and 88° C. Due to different assumptions between percentage of defective and all three temperature parameters, the suggested conditions from the two methods are then slightly different. Fortunately, the estimated percentage of defectives at 5.51% under GLM process...

In this paper, a technique for detecting faults in underground distribution system is presented. Discrete Wavelet Transform (DWT) based on traveling wave is employed in order to detect the high frequency components and to identify fault locations in the underground distribution system. The first peak time obtained from the faulty bus is employed for calculating the distance of fault from sending end. The validity of the proposed technique is tested with various fault inception angles, fault locations and faulty phases. The result is found that the proposed technique provides satisfactory result and will be very useful in the development of power systems protection scheme.

Aseptic loosening effects are critical issues in encouraging long term stability of cemented hip arthroplasty. Stress shielding is believed to be an important factor that contributes to the aseptic loosening problems. The numerous changes in the prosthesis stem design are intended to minimize the stress shielding and aseptic loosening problems and to improve the long term performance of the implants. In this study, the stress distribution in cemented hip arthroplasty is established using finite element method. The taper of the prosthesis is designed to be 3° at anterior/posterior, 3° at medial/lateral and 10° from wide lateral to narrow medial. Major muscle loads and contact forces are simulated for walking (toe‐off phase) and stair climbing load cases. Effects of prosthesis stem tapers on the resulting stress distribution are investigated. Results show that compressive stress dominates in the medial plane while tensile stress in the lateral plane of the femur. The corresponding stress levels of intact femur for walking and stair‐climbing load cases are 22 and 29 MPa, respectively. The magnitude of Tresca stress for the THA femur in stair‐climbing load case remains higher in the region of 85 MPa while the walking load case induces around 40 MPa. The stress range in the straight and single taper stem prosthesis is lower than 260 MPa, while localized Tresca stress is in the order of the yield strength of Ti‐6Al‐4V alloy for double and triple taper stem design.