bluuebunny/crossref_metadata_2025 huggingface dataset:
A Two-Tube Multiplex Reverse Transcription PCR Assay for Simultaneous Detection of Viral and Bacterial Pathogens of Infectious Diarrhea
Authors: Wang Ji , Xu Ziqian , Niu Peihua , Zhang Chen , Zhang Jingyun , Guan Li , Kan Biao , Duan Zhaojun , Ma Xuejun
Published: March 2014

Diarrhea caused by viral and bacterial infections is a major health problem in developing countries. The purpose of this study is to develop a two-tube multiplex PCR assay using automatic electrophoresis for simultaneous detection of 13 diarrhea-causative viruses or bacteria, with an intended application in provincial Centers for Diseases Control and Prevention, China. The assay was designed to detect rotavirus A, norovirus genogroups GI and GII, human astrovirus, enteric adenoviruses, and human bocavirus (tube 1), andSalmonella,Vibrio parahaemolyticus, diarrheagenicEscherichia coli,Campylobacter jejuni,Shigella,Yersinia,andVibrio cholera(tube 2). The analytical specificity was examined with positive controls for each pathogen. The analytical sensitivity was evaluated by performing the assay on serial tenfold dilutions of in vitro transcribed RNA, recombinant plasmids, or bacterial culture. A total of 122 stool samples were tested by this two-tube assay and the results were compared with those obtained from reference methods. The two-tube assay achieved a sensitivity of 20–200 copies for a single virus and 102-103 CFU/mL for bacteria. The clinical performance demonstrated that the two-tube assay had comparable sensitivity and specificity to those of reference methods. In conclusion, the two-tube assay is a rapid, cost-effective, sensitive, specific, and high throughput method for the simultaneous detection of enteric bacteria and virus.
Energy-Aware Distributed Clustering Algorithm for Improving Network Performance in WSNs
Authors: Kong Joon-Ik , Kim Jin-Woo , Eom Doo-Seop
Published: March 2014

Wireless sensor networks (WSNs) consist of a large number of sensor nodes equipped with a diverse number of small and low-cost devices with limited resources, such as a short communication range, a low bandwidth, a small memory, and a restricted energy. In particular, among these constraint factors, a sensor node's energy consumption is a very important factor in extending a network's lifetime. Many researchers are focused on the energy efficiency of wireless sensor networks. Many clustering algorithms have been proposed to improve energy efficiency. However, most protocols in previous literature have the problem of not considering the characteristics of real applications, for example, forest fire detection, intruder detection, target tracking, and the like. In this paper, we propose an energy-efficient clustering algorithm that can respond rapidly to unexpected events with increased energy efficiency, because each sensor node detects events individually and creates clusters using a regional competition scheme. Simulation results show improved performance when our algorithm is used.
Adsorption and Corrosion Inhibition Characteristics of Some Nicotinamide Derivatives on Mild Steel in Hydrochloric Acid Solution
Authors: Chakravarthy M. P. , Mohana K. N.
Published: March 2014

The present investigation includes the study of corrosion inhibition effect of N-(1H-Indol-3-ylmethylene)-nicotinamide (IMN) and N-(3,4,5-trimethoxy-benzylidene)-nicotinamide (TMN) on mild steel in 0.5 M HCl by mass loss and electrochemical measurements. The obtained results showed that inhibition efficiency increased with the increasing concentration of inhibitors and decreased with increase in temperature and immersion time. Potentiodynamic polarization curves indicate that both IMN and TMN were acting as mixed type of inhibitors. Langmuir adsorption isotherm model was employed to determine the equilibrium of adsorption for inhibiting process in both inhibitors. Nyquist plots revealed that, as the concentration of the inhibitors increases, double layer capacitance (Cdl) and corrosion current (icorr) decreases, while polarization resistance (Rp) increases. Various thermodynamic parameters for the adsorption of inhibitors on mild steel were computed and discussed. The passive film formed on the metal surface was characterized by FTIR, EDX, and SEM.
Microscopic Varicocelectomy Significantly Decreases the Sperm DNA Fragmentation Index in Patients with Infertility
Authors: Kadioglu Teoman Cem , Aliyev Emin , Celtik Murad
Published: March 2014

Background. Varicocele is associated with high levels of DNA damage in spermatozoa due to oxidative stress and elevated levels of sperm DNA fragmentation, which has been currently proposed to be an essential additional diagnostic test to be recommended for patients with clinical varicocele. The aim of this study was to evaluate the parameters of semen and the DNA fragmentation index (DFI) in patients with varicocele before and after varicocelectomy.Methods. The details of 92 consecutive patients were retrospectively analyzed from January 2010 to December 2012. The sperm samples were evaluated according to the World Health Organization Guidelines. Sperm DNA damage, characterized as DFI, was evaluated by sperm chromatin structure assay using flow cytometry.Results. There was a statistically significant improvement in the semen concentration, the total motile count, the total normal sperm count, and the sperm DNA fragmentation index (DFI; the percentage of sperm with denatured DNA) after varicocelectomy. There was a large decrease in DFI from a preoperative mean of 42.6% to a postoperative mean of 20.5% (P<0.001). A higher preoperative DFI was associated with a larger decrease in postoperative DFI, and significant negative correlations were observed between the DFI and sperm motility (r=-0.42,P<0.01).Conclusion. Our data suggest that varicocelectomy can improve multiple semen parameters and sperm DNA damage in infertile men with varicocele. The patients with preoperative defects in those parameters showed greater improvement postoperatively. Further research in this area is needed to understand the exact mechanisms of DNA damage in infertile men with varicocele.
A Case of Gorlin-Goltz Syndrome Presented with Psychiatric Features
Authors: Mufaddel Amir , AlSabousi Mouza , Salih Badr , AlHassani Ghanem , Osman Ossama T.
Published: March 2014

We report a case of a 34-year-old male who presented with an acute onset of pleomorphic psychiatric features. Upon examination we later diagnosed him with Gorlin-Goltz syndrome based on clinical and radiological findings that are characteristic for this rare autosomal dominant syndrome. His psychiatric manifestations included irritability, aggressive behavior, labile mood, hallucinations, paranoid delusions, and transient cognitive impairment. His past history indicated surgical excision of pigmented lesion in the left lower eyelid which turned out to be a basal cell carcinoma. His past visits to dermatology clinics indicated pitted keratosis involving hands, callosities, and seborrheic dermatitis. There were numerous palmar pits, and Brain CT Head scan revealed extensive calcification along falx cerebri and around the cerebellar vermis. He had low (20 ng/L) vitamin D level and high parathyroid hormone level. The patient improved using antipsychotic medications and vitamin D supplementations for symptomatic management and was discharged with a plan for multispecialty outpatient follow-up. This case highlights the importance of considering rare organic etiologies in the differential diagnosis of patients presenting with psychiatric symptoms. This is of vital importance for early intervention to prevent complications and for better outcomes of the coexistent diseases.
Lasting Effects of Workplace Strength Training for Neck/Shoulder/Arm Pain among Laboratory Technicians: Natural Experiment with 3-Year Follow-Up
Authors: Mortensen Peter , Larsen Anders I. , Zebis Mette K. , Pedersen Mogens T. , Sjøgaard Gisela , Andersen Lars L.
Published: March 2014

Objectives. This study investigated long-term effects and implementation processes of workplace strength training for musculoskeletal disorders.Methods. 333 and 140 laboratory technicians from private and public sector companies, respectively, replied to a 3-year follow-up questionnaire subsequent to a 1-year randomized controlled trial (RCT) with high-intensity strength training for prevention and treatment of neck, shoulder, and arm pain. Being a natural experiment, the two participating companies implemented and modified the initial training program in different ways during the subsequent 2 years after the RCT.Results. At 3-year follow-up the pain reduction in neck, shoulder, elbow, and wrist achieved during the first year was largely maintained at both companies. However, the private sector company was rated significantly better than the public sector company in (1) training adherence, (2) training culture, that is, relatively more employees trained at the workplace and with colleagues, (3) self-reported health changes, and (4) prevention of neck and wrist pain development among initially pain-free employees.Conclusions. This natural experiment shows that strength training can be implemented successfully at different companies during working hours on a long-term basis with lasting effects on pain in neck, shoulder, and arm.
Novel Closing Method Using Subcutaneous Continuous Drain for Preventing Surgical Site Infections in Radical Cystectomy
Authors: Hirose Yasuhiko , Naiki Taku , Ando Ryosuke , Nakane Akihiro , Etani Toshiki , Iida Keitaro , Akita Hidetoshi , Okamura Takehiko , Kohri Kenjiro
Published: March 2014

To reduce the incidence of surgical site infection (SSI) after radical cystectomy, a new closing method using subcutaneous continuous aspiration drain was developed and compared to the conventional closing method. The new method involved (a) closed aspiration with an indwelling aspiration drain without suture of the subcutaneous fat and (b) covering with hydrocolloid wound dressing after suture of the dermis with 4-0 absorbable thread and reinforcement using strips. The incidence of SSI was significantly improved by using the new method. Furthermore, univariate and multivariate analysis associated with SSI revealed that the new closing method was statistically correlated with 85% reduction of SSI (odds ratio: 0.15, 95% confidence interval: 0.03–0.69).Our new method using continuous aspiration with subcutaneous drain is useful for preventing SSI through removal of effusions and reduction of dead space by apposition of the subcutaneous fat.
New Realizations of Single OTRA-Based Sinusoidal Oscillators
Authors: Chien Hung-Chun
Published: March 2014

This study proposes three new sinusoidal oscillators based on an operational transresistance amplifier (OTRA). Each of the proposed oscillator circuits consists of one OTRA combined with a few passive components. The first circuit is an OTRA-based minimum RC oscillator. The second circuit is capable of providing independent control on the condition of oscillation without affecting the oscillation frequency. The third circuit exhibits independent control of oscillation frequency through a capacitor. This study first introduces the OTRA and the related formulations of the proposed oscillator circuits, and then discusses the nonideal effects, sensitivity analyses, and frequency stability of the presented circuits. The proposed oscillators exhibit low sensitivities and good frequency stability. Because the presented circuits feature low impedance output, they can be connected directly to the next stage without cascading additional voltage buffers. HSPICE simulations and experimental results confirm the feasibility of the new oscillator circuits.
Neonates in Ahmedabad, India, during the 2010 Heat Wave: A Climate Change Adaptation Study
Authors: Kakkad Khyati , Barzaga Michelle L. , Wallenstein Sylvan , Azhar Gulrez Shah , Sheffield Perry E.
Published: March 2014

Health effects from climate change are an international concern with urban areas at particular risk due to urban heat island effects. The burden of disease on vulnerable populations in non-climate-controlled settings has not been well studied. This study compared neonatal morbidity in a non-air-conditioned hospital during the 2010 heat wave in Ahmedabad to morbidity in the prior and subsequent years. The outcome of interest was neonatal intensive care unit (NICU) admissions for heat. During the months of April, May, and June of 2010, 24 NICU admissions were for heat versus 8 and 4 in 2009 and 2011, respectively. Both the effect of moving the maternity ward and the effect of high temperatures were statistically significant, controlling for each other. Above 42 degrees Celsius, each daily maximum temperature increase of a degree was associated with 43% increase in heat-related admissions (95% CI 9.2–88%). Lower floor location of the maternity ward within hospital which occurred after the 2010 heat wave showed a protective effect. These findings demonstrate the importance of simple surveillance measures in motivating a hospital policy change for climate change adaptation—here relocating one ward—and the potential increasing health burden of heat in non-climate-controlled institutions on vulnerable populations.
Measuring Outcome in an Early Intervention Program for Toddlers with Autism Spectrum Disorder: Use of a Curriculum-Based Assessment
Authors: Bacon Elizabeth C. , Dufek Sarah , Schreibman Laura , Stahmer Aubyn C. , Pierce Karen , Courchesne Eric
Published: March 2014

Measuring progress of children with autism spectrum disorder (ASD) during intervention programs is a challenge faced by researchers and clinicians. Typically, standardized assessments of child development are used within research settings to measure the effects of early intervention programs. However, the use of standardized assessments is not without limitations, including lack of sensitivity of some assessments to measure small or slow progress, testing constraints that may affect the child’s performance, and the lack of information provided by the assessments that can be used to guide treatment planning. The utility of a curriculum-based assessment is discussed in comparison to the use of standardized assessments to measure child functioning and progress throughout an early intervention program for toddlers with risk for ASD. Scores derived from the curriculum-based assessment were positively correlated with standardized assessments, captured progress masked by standardized assessments, and early scores were predictive of later outcomes. These results support the use of a curriculum-based assessment as an additional and appropriate method for measuring child progress in an early intervention program. Further benefits of the use of curriculum-based measures for use within community settings are discussed.
Weeding the Nettles II: A delimitation of “Urtica dioica L.” (Urticaceae) based on morphological and molecular data, including a rehabilitation of Urtica gracilis Ait.
Authors: Henning Tilo , Quandt Dietmar , Grosse-Veldmann Bernadette , Monro Alexander , Weigend Maximilian
Published: March 2014

The taxonomy of subcosmopolitan Urtica dioica L. s.l. is problematic. Recent floras recognize Urtica dioica as a subcosmopolitan species ranging throughout the entire holarctic region and also South Africa and New Zealand. Numerous infraspecific taxa have been proposed, especially in western Eurasia. There is only weak character differentiation, with floral and fruit morphology largely uniform, details of leaf morphology and indumentum are therefore primarily used for species delimitation, together with some characters of gender distribution and growth habit. The present study addresses the enigmatic relationships of the infraspecific taxa in Urtica dioica with a special emphasis on the monoecious, American representatives of Urtica dioica s.l. The study is based on extensive field and herbarium studies, molecular data and the experimental cultivation of all relevant forms. Infraspecific taxa currently assigned to U. dioica are retrieved mainly on two separate clades, one comprising the predominantly polygamous western Eurasian and African taxa (all subspecies and varieties sampled), the other comprising the monoecious American taxa. Monoecious American representatives of “Urtica dioica” and closely allied taxa (U. aquatica, U. mollis) are retrieved as a monophyletic group sister to a clade with East Asian and Australasian species, this clade is then retrieved as sister to the western and central Eurasian and African taxa of U. dioica. We therefore advocate the removal of the American representatives of this group from Urtica dioica and their placement as infraspecific taxa under Urtica gracilis. The following new names are consequently proposed: Urtica gracilis subsp. gracilis (for Urtica dioica subsp. gracilis), Urtica gracilis subsp. holosericea, comb. nov. (for Urtica dioica subsp. holosericea), Urtica gracilis subsp. aquatica, comb. & stat. nov. (for Urtica aquatica), Urtica gracilis subsp. mollis, comb. & stat. nov. (for Urtica mollis). Additionally, we describe a new subspecies from Peru under the name Urtica gracilis subsp. incaica. The literature report of Urtica gracilis (dioica subsp. gracilis) as an introduced weed in New Zealand is shown to be erroneous – the corresponding specimens belong to Australian Urtica incisa. Based on gross morphology close affinities have been proposed between a range of Australasian, Asian, North American and European infraspecific taxa, all of these can be shown to be erroneous.
Two new species of the Simulium batoense species-group of Simulium (Gomphostilbia) (Diptera: Simuliidae) from Peninsular Malaysia
Authors: TAKAOKA HIROYUKI , SOFIAN-AZIRUN MOHD , YA’COB ZUBAIDAH
Published: March 2014

Two new black fly species, Simulium (Gomphostilbia) tekamense and Simulium (Gomphostilbia) jerantutense, are described based on adult females emerged from pupae in Peninsular Malaysia, and assigned to the binuanense subgroup of the batoense species-group in the subgenus Gomphostilbia. Simulium (G.) tekamense sp. nov. is characterized in the female by the subcosta with 0–2 hairs, and presence of a  deep notch on the apex of the mediolongitudinal ridge of the cibarium, and in the pupa by one of two paired gill filaments of the middle triplet much thicker than the counter filament. Simulium (G.) jerantutense sp. nov. is characterized in the female by the short claw tooth 0.46 times the length of the claw, and in the pupa by the gill filaments arranged as [2+1+(1+2)]+2 filaments from dorsal to ventral. Taxonomic notes are given to distinguish these new species from related species.
Book Review: Pedagogy for Religion: Missionary Education and the Fashioning of Hindus and Muslims in Bengal
Authors: Banerjee-Dube Ishita
Published: March 2014

PARNA SENGUPTA, Pedagogy for Religion: Missionary Education and the Fashioning of Hindus and Muslims in Bengal, Berkeley and Los Angeles: University of California Press, 2011, pp. 211.
Trends in media and communication studies: Toddlers, media consumption, and development communication
Authors: Sooryamoorthy Radhamany
Published: March 2014

The growing field of media studies continues to attract the interest of researchers who closely watch the diffusion and usage pattern of the media. New forms of media that integrate a number of media and communication technologies into a single device (like the latest invention of smart watches) further necessitate intensive research in this field. Until recently, scholars who followed the growth and development of the media focused more on the younger generation and their media consumption patterns. This focus has now shifted to very young children, including toddlers, as their exposure to media has of late tended to change significantly. The early exposure to forms of media, whether television or the internet, has implications for the media industry. At the same time, the communication side of the media has been influencing development initiatives on several fronts.
Effects on Ni and Cd speciation in sewage sludge during composting and co-composting with steel slag
Authors: Zeng Zheng-zhong , Wang Xiao-li , Gou Jian-feng , Zhang He-fei , Wang Hou-cheng , Nan Zhong-ren
Published: March 2014

Sewage sludge and industrial steel slag (SS) pose threats of serious pollution to the environment. The experiments aimed to improve the stabilizing effects of heavy metal Ni and Cd morphology in composting sludge. The total Ni and Cd species distribution and chemical forms in the compost sewage sludge were investigated with the use of compost and co-compost with SS, including degradation. The carbon/nitrogen ratio of piles was regulated with the use of sawdust prior to batch aerobic composting experiments. Results indicated that the co-composting with SS and organic matter humification can contribute to the formation of Fe and Mn hydroxides and that the humus colloid significantly changed Ni and Cd species distribution. The decreased content of Ni and Cd in an unstable state inhibited their biological activity. Conclusions were drawn that an SS amount equal to 7% of the dry sludge mass was optimal value to guarantee the lowest amount of Cd in an unstable state, whereas the amount was 14% for Ni.
Recycling potential of air pollution control residue from sewage sludge thermal treatment as artificial lightweight aggregates
Authors: Białowiec Andrzej , Janczukowicz Wojciech , Gusiatin Zygmunt M , Thornton Arthur , Rodziewicz Joanna , Zielińska Magdalena
Published: March 2014

Thermal treatment of sewage sludge produces fly ash, also known as the air pollution control residue (APCR), which may be recycled as a component of artificial lightweight aggregates (ALWA). Properties of APCR are typical: high content of Ca, Mg, P2O5, as well as potential to induce alkaline reactions. These properties indicate that ALWA prepared with a high content of APCR may remove heavy metals, phosphorus, and ammonium nitrogen from wastewater with high efficiency. The aim of this preliminary study was to determine the optimal composition of ALWA for potential use as a filter media in wastewater treatment systems. Five kinds of ALWA were produced, with different proportions of ash (shown as percentages in subscripts) in mixture with bentonite: ALWA0 (reference), ALWA12.5, ALWA25, ALWA50, and ALWA100. The following parameters of ALWA were determined: density, bulk density, compressive strength, hydraulic conductivity, and removal efficiency of ions Zn2+, NH4+, and PO43−. Tests showed that ALWA had good mechanical and hydraulic properties, and might be used in wastewater filtering systems. Phosphates and zinc ions were removed with high efficiency (80-96%) by ALWA25-100 in static (batch) conditions. The efficiency of ammonium nitrogen removal was low, <18%. Artificial wastewater treatment performance in dynamic conditions (through-flow), showed increasing removal efficiency of Zn2+, PO43− with a decrease in flow rate.
Urban network traffic control
Authors: Hounsell N B , McDonald M
Published: March 2014

The optimum control of traffic in urban networks is an important requirement of city authorities as they seek efficient and sustainable transport. A feature of most urban networks is the high density of city streets with numerous road junctions, which require efficient control mechanisms if congestion is to be contained. Traffic signals have become the most widely used form of control in this context, with increasing sophistication in detection and real-time optimization providing new levels of efficiency. A changing policy background in many cities has also required greater emphasis in traffic control on the needs of public transport, cyclists and pedestrians, and on the need to minimize vehicle emissions. This paper provides an overview of problems, methods, systems and applications in the context of urban network traffic control, concluding with a look at future needs. The paper focuses particularly on signallized junctions within computer-controlled urban traffic control (UTC) systems, which are increasingly at the heart of traffic control in cities around the world.
Review of non-intrusive advanced sensor devices for advanced traffic management systems and recent advances in video detection
Authors: Michalopoulos P , Hourdakis J
Published: March 2014

As performance requirements for advanced traffic management systems (ATMSs) increase, the need for new sensors leading to the next-generation traffic management systems is manifested. In spite of the wide array of non-intrusive technologies that are available today, most are not new. Even though earlier technologies continue to improve, most are fundamentally unsuitable for traffic detection, and their widespread use does not appear to be imminent. As a result, most traffic management centres (TMCs) being built today continue to rely on an old but established in-pavement technology, namely loop detectors. Perceived cost and reliability notwithstanding, the major physical disadvantage of loops, as well as of most technologies (intrusive or not), is their inability to detect traffic over a wide area and extract critical traffic measurements such as queues, density, stops and others. In this paper, non-intrusive technologies are briefly reviewed, and particular emphasis is given to the most promising and increasingly accepted in the field, namely machine vision. Since the technology is only recently accepted, representative major field deployment projects are also included.
Adaptive control of multiple robots manipulation on a dynamical environment
Authors: Tuneski A I , Vukobratovic M K , Dimirovski G M
Published: March 2014

Adaptive control of multiple compliant manipulation on a dynamical environment is synthesized. It may be implemented when (a) there is no good understanding of all physical effects incorporated in the multiple robots-object-environment system to be controlled, (b) the parameters of the system are not precisely known and (c) the system parameters do vary in known regions about their nominal values. The proposed adaptive control law has the inverse dynamics controller structure and is composed of an identification part (parameter update law) and a control law part. It is proved that the proposed adaptive controller is asymptotically stable. The simulation results verify the proposed approach to coordinated adaptive control of multiple robot manipulators in constrained motion tasks. They also verify that the multiple robots-object-environment system can track a step parameter change.
Robust tracking via sliding mode control for elastic joint manipulators
Authors: Spurgeon S K , Yao L , Lu X Y
Published: March 2014

A new scheme is presented for the robust tracking control of robot manipulators in the presence of model uncertainty and disturbances. Based on the robust sliding mode control methodology, the control scheme addresses the following problem: given the extent of parametric uncertainty and the external uncertainties, design a non-linear sliding mode controller to achieve robust tracking precision. The explicit robustness guarantees provided by the methodology are demonstrated using elastic joint manipulator models. The methodology is compared with the traditional feedback linearization.
Designing hydraulic locking balancing grooves
Authors: Milani M
Published: March 2014

The paper deals with the analysis of the influence of the groove axial length, number and position on the total side thrust acting on a spool inserted into a tapered clearance. Adopting a numerical approach based on the Reynolds equation properly combined with the continuity equation, the hydraulic locking phenomena are studied for different tapered clearances of practical interest in the presence of different groove configurations. The variation in groove axial length, number and thin film of fluid, including fundamental data for a proper spool design.
Robust H∞ control for uncertain state-delayed systems with sector non-linearity
Authors: Xu S , Lam J
Published: March 2014

This paper deals with the problem of robust H∞ control for uncertain state-delayed systems containing sector non-linearity. The parameter uncertainties are assumed to be time varying and unknown but norm bounded. Based on the linear matrix inequality (LMI) approach, both delay-independent and delay-dependent techniques for designing memoryless state feedback controllers are proposed to stabilize the delay system, and to reduce the effect of the disturbance input on the controlled output to a prescribed level for all admissible uncertainties. Numerical examples are employed to illustrate the results.
Semi-empirical model for a hydraulic servo-solenoid valve
Authors: Ferreira J A , de Almeida F Gomes , Quintas M R
Published: March 2014

High-performance proportional valves, also called servo-solenoid valves, can be used today in closed-loop applications that previously were only possible with servo-valves. The valve spool motion is controlled in a closed loop with a dedicated hardware controller that enhances the valve frequency response and minimizes some non-linear effects. Owing to their lower cost and maintenance requirements as well as increasing performance they can compete with servo-valves in a large number of applications. This paper describes a new semi-empirical modelling approach for hydraulic proportional spool valves to be used in hardware-in-the-loop simulation experiments. The developed models use either data sheet or experimental values to fit the model parameters in order to reproduce both static (pressure gain, leakage flowrate and flow gain) and dynamic (frequency response) valve characteristics. Valve behaviour is divided into two parts: the static behaviour and the dynamic behaviour. A parameter decoupled model, with a variable equation structure, and a flexible model, with a fixed equation structure, are proposed for the static part. Spool dynamics are modelled by a non-linear second-order system, with limited velocity and acceleration, the parameters being adjusted using optimization techniques.
A neural network enhanced generalized minimum variance self-tuning proportional, integral and derivative control algorithm for complex dynamic systems
Authors: Zhu Q M , Warwick K
Published: March 2014

A neural network enhanced proportional, integral and derivative (PID) controller is presented that combines the attributes of neural network learning with a generalized minimum-variance self-tuning control (STC) strategy. The neuro PID controller is structured with plant model identification and PID parameter tuning. The plants to be controlled are approximated by an equivalent model composed of a simple linear submodel to approximate plant dynamics around operating points, plus an error agent to accommodate the errors induced by linear submodel inaccuracy due to non-linearities and other complexities. A generalized recursive least-squares algorithm is used to identify the linear submodel, and a layered neural network is used to detect the error agent in which the weights are updated on the basis of the error between the plant output and the output from the linear submodel. The procedure for controller design is based on the equivalent model, and therefore the error agent is naturally functioned within the control law. In this way the controller can deal not only with a wide range of linear dynamic plants but also with those complex plants characterized by severe non-linearity, uncertainties and non-minimum phase behaviours. Two simulation studies are provided to demonstrate the effectiveness of the controller design procedure.
Composite adaptive control of a robotic joint for passive deployment applications
Authors: Reedman A V C , Bouazza-Marouf K
Published: March 2014

A composite adaptive control scheme for the control of an actively constrained revolute joint with backlash cancellation is presented in this paper. The drive mechanism consists of two motor-driven worms coupled to a single worm wheel. The mathematical model and control strategies are reviewed. This is followed by the derivation of the composite adaptive controllers. Simulation and experimental results show that the composite adaptive control scheme gives an equivalent performance to a computed-torque algorithm without compromising the mechanism's ability to cancel backlash.
A modification of cooperative collision avoidance for multiple mobile robots using the avoidance circle
Authors: Fujimori A , Ogawa Y , Nikiforuk P N
Published: March 2014

This paper presents a modification of cooperative collision avoidance for multiple mobile robots. The original cooperative collision avoidance technique by Fujimori and co-workers is briefly explained and its drawbacks are shown in the navigation simulation using a simulator of an experimental robot, Pioneer-1. To improve upon the drawbacks, an avoidance circle is introduced and a modified cooperative collision avoidance technique is proposed. The improved performance of the proposed modification is demonstrated by another navigation simulation in which the conditions are the same as those in the simulation using the original technique. For 100 trials using four mobile robots, the number of the successful cases using the original and the modified techniques was 74 and 96 respectively.
Measuring the dew point temperature of humid air using a photoelectric system
Authors: Mehrabian M A , Ziaebrahimi A
Published: March 2014

An instrument is designed and constructed to allow direct measurements to be taken of the dew point temperature of humid air. The principle uses the photoelectric system to detect the instant at which the vapour flowing over a mirror begins to condense and cloud up a mirror that is being alternately heated and cooled. A series of experimental data are extracted in different environments using this instrument. The data are in good agreement with the results obtained from analytical calculations and a psychrometric chart. The experimental data show an approximate relationship between the relative humidity and the dew point differential; i.e. for a dew point differential of 6°C below the dry bulb temperature, the relative humidity of the air is approximately 70 per cent over a moderate range of dry bulb temperatures, regardless of the barometric pressure.
Sliding mode tracking control of a low-pressure water hydraulic cylinder under non-linear friction
Authors: Cho S H , Linjama M , Sairiala H , Koskinen K T , Vilenius M
Published: March 2014

This paper deals with a robust motion control of a low-pressure water hydraulic cylinder under non-linear friction. In order to ensure good tracking performance as well as to guarantee robustness, the sliding mode tracking control is utilized in combination with a non-linear friction compensator. Application of the scheme to a low-pressure water hydraulic cylinder position control has led to a significant reduction in tracking error when compared with the perfect tracking control scheme.
Dynamic modelling and open-loop control of a twin rotor multi-input multi-output system
Authors: Ahmad S M , Chipperfield A J , Tokhi M O
Published: March 2014

A dynamic model for a one-degree-of-freedom (DOF) twin rotor multi-input multi-output (MIMO) system (TRMS) in hover is obtained using a black-box system identification technique. The behaviour of the TRMS in certain aspects resembles that of a helicopter; hence, it is an interesting identification and control problem. This paper investigates modelling and open-loop control of the longitudinal axis alone, while the lateral axis movement is physically constrained. It is argued that some aspects of the modelling approach presented are suitable for a class of new generation or innovative air vehicles with complex dynamics. The extracted model is employed for designing and implementing a feedforward/open-loop control. Open-loop control is often the preliminary step for development of more complex feedback control laws. Open-loop control strategies using shaped command inputs are accordingly investigated for resonance suppression in the TRMS. Digital low-pass and band-stop filter shaped inputs are used on the TRMS testbed, based on the identified vibrational modes. A comparative performance study is carried out and the corresponding results presented. The low-pass filter is shown to result in better vibration reduction.
A non-linear multiple-model state estimation scheme for pipeline leak detection and isolation
Authors: Emara-Shabaik H E , Khulief Y A , Hussaini I
Published: March 2014

Model-based monitoring schemes are known to have a great potential in detection and localization of leaks in pipelines. Fluid flow in pipelines is characterized by a system of non-linear-coupled partial differential equations. Since state estimation can provide the basis for real-time monitoring of fluid flow in pipelines, a suitable numerical scheme is employed to formulate the problem in state-space form, which enables the development of state estimation techniques. A modified extended Kalman filter (MEKF) in conjunction with feed forward computations to anticipate the leak magnitude provides the core of the adaptive multimodel state estimation technique used in this paper. Numerical simulation results show that the developed state estimation scheme effectively detects and locates small leaks in pipelines within a short time duration.
Non-regular static state feedback for linear bond graph models
Authors: Karim A , Sueur C , Dauphin-Tanguy G
Published: March 2014

In this paper, non-regular static state feedback solutions of the row-by-row decoupling problem (RBRDP) with stability are investigated by the bond graph approach for the class of non-square linear models. More precisely, the aim is to study the problem of the non-regular static state feedback designing, firstly, when the model is not decouplable with a regular static state feedback and, secondly, when the model is decouplable with a regular static state feedback but not with stability. The bond graph methodology is used in order to characterize the structure of non-square models and the modification of the infinite structure that arises when a regular control law cannot exist. A new graphical methodology is proposed. Finally, when row-by-row decoupling with stability is possible for non-square bond graph models, a formal expression of the control is given using simultaneously the bond graph and the geometric approaches.
Design of a semi-autonomous modular robotic vehicle for gas pipeline inspection
Authors: Ong J K , Kerr D , Bouazza-Marouf K
Published: March 2014

This paper presents a new solution for inspecting and repairing defects in live gas pipelines. The proposed approach is the development of a modular and semi-autonomous vehicle system. The robotic system has a drive mechanism, capable of navigating and adjusting its orientation in various configurations of pipelines. Other features of the system are cable-free communications, semi-autonomous motion control as well as integration of sensory devices. The robotic system is designed to traverse in 150–300 mm diameter pipes through straight and curved sections, junctions and reducers. The vehicle control and navigation technique is implemented using a two-mode controller consisting of a proportional-integral-derivative (PID) and fuzzy logic control. Unlike other available systems, the vehicle employs proprioceptive sensors to monitor its own states. The fuzzy logic controller is used to evaluate the sensor outputs such as speed, climbing angle and rate of change of climbing angle. This control technique allows the vehicle to drive and adapt in a partially observable gas pipe system. Laboratory experiment results are presented. The paper also describes a cable-free communication method for the system. A brief account of typical pipe environments and currently available inspection tools is presented as background information.
Model predictive temperature control towards improving cement precalcination
Authors: Koumboulis F N , Kouvakas N D
Published: March 2014

In the present paper, the degree of precalcination in the precalciner of cement plants is increased via a proportional-integral (PI) model predictive abgasses temperature controller. The controller is based on polynomial neural network identification of the plant at a particular operating point as well as on a polynomial non-linear predictor depending on autoregressive identification predictors of temperature disturbances. According to simulation results, the degree of precalcination becomes significantly increased while energy consumption is reduced.
An adjustable parameter model for tracking a manoeuvring target
Authors: Sun H-M , Lin T-L
Published: March 2014

An adjustable parameter model for tracking manoeuvring targets is presented using a modified variable variance intensity technique. This model is based on the Singer model but with modifications to its fixed manoeuvre statistical characteristics. Meanwhile, a ‘current model’ concept is adapted to describe the statistical distribution of the target's acceleration. Since the variance intensity of the proposed model is calculated using a variable manoeuvring probability density function with adequate covariance, it exhibits a strong adaptive ability for tracking a manoeuvring target and a reduced steady estimation bias in tracking a non-manoeuvring target. Computer simulation results show that a Kalman estimator based on this model can track both manoeuvring and non-manoeuvring targets with greater accuracy than either the Singer model or the interacting multiple model method and is suitable for online processing.
Design of a strip thickness control system for tandem cold mills using H∞ control techniques
Authors: Kim S S , Kim J S , Yang S Y , Lee B R , Ahn K K
Published: March 2014

In order to meet the requirement for higher thickness accuracy in cold-rolling mill processes, it is strongly desired to have an increasing high performance in control units. To meet this requirement, an output regulating control system with a roll-eccentricity estimator for each rolling stand of tandem cold mills was considered. Assuming entry thickness variation as well as roll eccentricity to be the major disturbances, a synthesis of multivariable control systems is presented and based on H∞ control theory, which can reflect knowledge of the input direction and spectrum of disturbance signals on design. Then, to reject roll eccentricity effectively, a weight function having some poles on the imaginary axis is introduced. This leads to a non-standard H∞ control problem, and the design procedures for solving this problem are analytically presented. The effectiveness of the proposed control method is evaluated through computer simulations and compared with the conventional linear quadratic control and feedforward control methods for roll eccentricity.
Design, control and testing of a novel compact laparoscopic endoscope manipulator
Authors: Berkelman P , Cinquin P , Boidard E , Troccaz J , Létoublon C , Ayoubi J-M
Published: March 2014

This paper describes the development of a compact laparoscopic endoscope manipulator and its command interface for use as a surgical assistant during minimally invasive surgery. The defining feature of the endoscope manipulator is that it is sufficiently small and lightweight to be fixed directly on the abdomen of the patient. The mechanism of the manipulator controls the orientation of the endoscope and its insertion depth. It is actuated by cables inside flexible sleeves connected to a separate enclosure containing analogue controllers, servomotors and rack-and-pinion drives. Compared with floor-standing endoscope manipulators, the described device is easier to set up, cheaper, simpler and allows unrestricted access to the abdomen from all sides of the patient. The pointing accuracy of the device is reduced by the absence of a rigid base, but the resulting compliance to patient motion is an added benefit. The current prototype has been tested on a cadaver. The design and control of the endoscope manipulator continues to evolve in response to testing results and consultation with surgeons, with light weight, small size, simplicity and ease of use as primary considerations. A novel hands-free user control interface for orientation of the endoscope manipulator using an external optical localizer to track surgical instruments is also presented.
Fuzzy and neuro-fuzzy approaches to control a flexible single-link manipulator
Authors: Subudhi B , Morris A S
Published: March 2014

In this paper, new fuzzy and neuro-fuzzy approaches to tip position regulation of a flexible-link manipulator are presented. Firstly, a non-collocated, proportional-dervative (PD) type, fuzzy logic controller (FLC) is developed. This is shown to perform better than typical model-based controllers (LQR and PD). Following this, an adaptive neuro-fuzzy controller (NFC) is described that has been developed for situations where there is payload variability. The proposed NFC tunes the input and output scale parameters of the fuzzy controller on-line. The efficacy of the NFC has been evaluated by comparing it with a fuzzy model reference adptive controller (FMRC).
H-infinity error bounds in approximating time-delay systems
Authors: Al-Amer S H , Al-Sunni F M
Published: March 2014

In this paper, upper and lower bounds on approximating time-delay systems are proposed. Bounds on the infinity norm of the weighted error are obtained when the approximating function is a general rational function, an all-pass function or Pade and Laguerre approximations. In addition, approximations of the weighted errors for both Pade and Laguerre approximating functions are developed. Examples are presented in illustration.
Design and control of a spherical mobile robot
Authors: Alves J , Dias J
Published: March 2014

This paper describes a type of mobile robot with a spherical shape designed to act as a platform to carry sensing devices or actuators in an environment where the conditions are harsh and the stability of the mechanical platform is critical. A remotely controlled internal unit drives the spherical robot. The paper focuses on the design and motion control of a robot with a spherical shape. The developed control modules are implemented in digital programmable logic devices, using a hardware description language named VHDL. The digital hardware controls multiple devices: a multichannel analogue-to-digital (A/D) converter, a pair of radio-frequency (RF) modules and four radio-controlled (R/C) servos. The robot motion is modelled by a configuration space function using the path curvature. The motion controller was designed to drive the robot to the desired path using control based on the path curvature. Because of the lack of a special steering mechanism, the robot steers only by controlling the displacement of its centre of gravity.
Remarks on the stability of parallel force/position control
Authors: Cervantes I , Arteaga-Perez M , Alvarez-Ramirez J , Gudiño J
Published: March 2014

The aim of this paper is to study the force/position regulation problem of robot manipulators using the well-known parallel control approach. An alternate proof of previous results is presented to show that the robot system is closed-loop stable when the gravitational effects are not exactly compensated and that the desired force can always be reached. A systematic procedure of control synthesis is presented and stability conditions for the control parameters are derived. The used approach also shows that the original algorithm can be simplified, even in the case when no velocity measurements are available. The performance of the proposed controller is verified through an experimental application.