Tuning System Research Articles

Interferometric diameter determination of a silicon sphere using a traceable single laser frequency synthesizer

To determine the absolute diameter of a silicon sphere for the Avogadro constant project, we present a phase-shifting interferometer based on a flat etalon and a traceable single laser frequency synthesizer. By using an optical frequency comb to calibrate a frequency-tunable diode laser, the single laser frequency synthesizer can produce an arbitrary laser frequency with a relative uncertainty of 9.2 × 10−12 in the range of 4 THz. According to the laser frequency tuning system, the Carré algorithm with arbitrary but equal phase steps is employed to calculate the fractional interference phases. The absolute diameter is obtained by measuring the fractional and integral parts based on the principles of phase-shifting interferometry and frequency-sweeping interferometry, respectively. The uncertainty of a single diameter measurement in air is estimated to be 5 nm, whose uncertainty sources from the laser frequency and the phase-shifting algorithm are negligible.

Particle Swarm Optimization (PSO) Based Topology Optimization of Part Design with Fuzzy Parameter Tuning

In order to improve the performance of the Particle Swarm Optimization (PSO) scheme on topology optimization of a part design, a fuzzy parameter tuning system is introduced in this study. Because thecorrelation and effect of constraints in PSO based topology optimization are uncertain and not well defined, a fuzzy logic system is used to adjust the constraints in PSO. After setting up the mathematical model, two illustrative examplesrunning in MATLAB environment are used to compare the performance of three topology optimization schemes: the Solid Isotropic Material with Penalization (SIMP) scheme, the standard PSO based topology optimization scheme and the fuzzy logic based PSO topology optimization scheme. It is found that, fuzzy logic based PSO has better search performance and efficiency than the standard PSO.

Bioefficacy of hydromethanolic extract of tuber ofChlorophytum borivilianum(Safed Musli) for the management of male infertility in cyproterone acetate-treated albino rats

Increase in male sexual dysfunction, and its treatment with conventional aphrodisiac drugs with side effects lead to investigate the spermatogenesis and androgenesis augmentative efficacy of hydromethanolic (40 : 60) extract of root of Chlorophytum borivilianum (family - Liliaceae) against cyproterone acetate-induced subfertility in Wistar strain male albino rat. For this purpose, experimental rats were divided into three treatment groups: vehicle (received distilled water), cyproterone acetate (gastric intubation at 250 mg kg(-1) twice daily for 35 days) and cyproterone acetate plus root extract of C. borivilianum (gastric intubation at 250 mg kg(-1) plus 400 mg kg(-1) with an interval of 20 min twice daily for 35 days). After 35-day treatment, all rats were euthanised. Reproductive deviations towards negative side were investigated by screening the spermatogenic and steroidogenic biosensors. Oxidative stress profile in reproductive organs and sperm pellet was evaluated by biochemical assessment of antioxidative enzyme activities and level of end products of the lipid peroxidation. Apoptosis profile was evaluated by Western blot study, TUNEL assay and DNA fragmentation study of testicular tissues. Evaluation of toxicity profile was included for experimental investigation. After cyproterone acetate treatment, the pituitary-testicular axis was deviated towards the negative side and its tuning system was affected by oxidative stress and apoptosis-mediated process, which reduced the quality of semen and finally led to subfertility. Co-administration of C. borivilianum root extract enhanced male reproductive potentiality and prevented the negative deviations after the treatment with cyproterone acetate by means of increasing oxidative defence and maintaining homeostasis in testicular apoptosis process.

A tuning system for BEPC II

The tuning system plays a very important role when a superconducting cavity is in operation. It cooperates with other control loops to adjust the cavity frequency with high precision, reduce the reflection power, guarantee the stability of beam, and ensure the safety of the superconducting cavity. This paper focuses mainly on the tuning system working principle, the working state and problems that Beijing Electron Positron Collider (BEPC II) has encountered during operation.

Four-part choral synthesis system for investigating intonation in a cappella choral singing

Accurate tuning is an important aspect of singing in harmony in the context of a choir or vocal ensemble. Tuning and ‘pitch drift’ are concerning factors in performance for even the most accomplished professional choirs when singing a cappella (unaccompanied). In less experienced choirs tuning often lacks precision, typically because individual singers have not developed appropriate listening skills. In order to investigate accuracy of tuning in ensemble singing situations, a chorally appropriate reference is required against which frequency measurements can be made. Since most basic choral singing involves chords in four parts, a four-part reference template is used in which the fundamental frequencies of the notes in each chord can be accurately set. This template can now be used in experiments where three of the reference parts are tuned in any musical temperament (tuning system), in this case equal and just temperaments, and played over headphones to a singer to allow her/his tuning strategy to be investigated. This paper describes a practical implementation of a four-part choral synthesis system in Pure Data (Pd) and its use in an investigation of tuning of notes by individual singers using an exercise originally written to explore pitch drift in a cappella choral singing.

A Descriptive Analysis of Performance Models’ Intonation in a Recorded Excerpt from Suzuki Violin School Volume I

Given the importance of modeling in teaching young students to perform, particularly in the Suzuki approach, as well as the importance of playing in-tune, we studied intonation performances on four recordings of Suzuki Violin School Volume I. These are performances that many string teachers recommend as models for beginning string students. We also asked whether performances conform to a theoretical tuning system such as equal temperament (ET) or Pythagorean tuning. We analyzed the first eight measures and the repeat of Minuet I (Bach) in G-major. Individual note deviations of performers ranged from -17 cents to +26 cents relative to the accompaniment, although most deviations were smaller. Overall, three performers tended to be closer to Pythagorean (which is slightly sharper than ET for most major intervals) while one was closer to ET. However, inspection of individual intervals showed that two of the performers were often sharp relative to both tuning systems, particularly for minor seconds and thirds, and major thirds. No performer consistently conformed to either tuning system across the span of notes in the excerpt.

Method for fabrication and verification of conjugated nanoparticle-antibody tuning elements for multiplexed electrochemical biosensors

There is a critical need for more accurate, highly sensitive and specific assay for disease diagnosis and management. A novel, multiplexed, single sensor using rapid and label free electrochemical impedance spectroscopy tuning method has been developed. The key challenges while monitoring multiple targets is frequency overlap. Here we describe the methods to circumvent the overlap, tune by use of nanoparticle (NP) and discuss the various fabrication and characterization methods to develop this technique. First sensors were fabricated using printed circuit board (PCB) technology and nickel and gold layers were electrodeposited onto the PCB sensors. An off-chip conjugation of gold NP’s to molecular recognition elements (with verification technique) is described as well. A standard covalent immobilization of the molecular recognition elements is also discussed with quality control techniques. Finally use and verification of sensitivity and specificity is also presented. By use of gold NP’s of various sizes, we have demonstrated the possibility and shown little loss of sensitivity and specificity in the molecular recognition of inflammatory markers as “model” targets for our tuning system. By selection of other sized NP’s or NP’s of various materials, the tuning effect can be further exploited. The novel platform technology developed could be utilized in critical care, clinical management and at home health and disease management.

Quantum criticality at high temperature revealed by spin echo

Quantum criticality occurs when the ground state of a macroscopic quantum system changes abruptly on tuning system parameters. It is an important indicator of new quantum matters emerging. In conventional methods, quantum criticality is observable only at zero or low temperature (as compared with the interaction strength in the system). We find that a quantum probe, if its coherence time is long, can detect the quantum criticality of a system at high temperature. In particular, the echo control over a spin probe can remove the thermal fluctuation effects and hence reveal the critical quantum fluctuation without requiring low temperature. We first use the exact solution of the one-dimensional transverse-field Ising model to demonstrate the possibility of detecting the quantum criticality at high temperature by spin echo. The critical behaviors were calculated using the exact solution and understood by the noise spectrum analysis in the Gaussian noise approximation. By numerical simulation, we further verify that the high-temperature quantum criticality also exists in the probe coherence measurement of spin systems with dipolar couplings. Using the noise spectrum analysis, we establish the correspondence between the necessary low temperature (TQC) in conventional methods and the necessary long coherence time (tQC) in probe decoherence measurement to observe the quantum criticality, that is, TQC ∼ 1/tQC and much less than the interaction strength of the system. For example, probes with quantum coherence times of milliseconds or seconds can be used to study, without cooling the system, quantum criticality that was previously known to be only observable at extremely low temperatures of nano- or pico-kelvin. This finding provides a new possibility to study quantum matters.

Adaptive neuro-fuzzy technique for performance tuning of database management systems

A recent trend in database performance tuning is towards self tuning for some of the important benefits like efficient use of resources, improved performance and low cost of ownership that the auto-tuning offers. Most modern database management systems (DBMS) have introduced several dynamically tunable parameters that enable the implementation of self tuning systems. An appropriate mix of various tuning parameters results in significant performance enhancement either in terms of response time of the queries or the overall throughput. The choice and extent of tuning of the available tuning parameters must be based on the impact of these parameters on the performance and also on the amount and type of workload the DBMS is subjected to. The tedious task of manual tuning and also non-availability of expert database administrators (DBAs), it is desirable to have a self tuning database system that not only relieves the DBA of the tedious task of manual tuning, but it also eliminates the need for an expert DBA. Thus, it reduces the total cost of ownership of the entire software system. A self tuning system also adapts well to the dynamic workload changes and also user loads during peak hours ensuring acceptable application response times. In this paper, a novel technique that combines learning ability of the artificial neural network and the ability of the fuzzy system to deal with imprecise inputs are employed to estimate the extent of tuning required. Furthermore, the estimated values are moderated based on knowledgebase built using experimental findings. The experimental results show significant performance improvement as compared to built in self tuning feature of the DBMS.

How to Determine the Topology of Hierarchical Tuning Networks for Dynamic Auto-tuning in Large-scale Systems

Automatic analysis and tuning is a key strategy that helps to exploit the potential of high performance systems. However, for parallel applications with long running times, dynamic behaviour or highly data dependent performance patterns, it is necessary to make use of the strength of dynamic auto-tuning. An important factor in dynamic auto-tuning on a large scale is the number of additional resources required by the tuning system itself in order to reduce impact on the application performance. A tradeoff must be made between the loss of effectiveness of a tuning system using too few resources and the loss of its efficiency using too many resources. Most automatic analysis or tuning systems do not provide assistance for defining how many additional resources are required. In this work, we address this problem proposing a method focused on calculating the structure of hierarchical tuning networks. The topology will be composed of the minimum number of non-saturated resources. Experimental evaluation performed covers different use cases, each one showing that tuning networks built according to our proposal make efficient use of resources, while providing a high quality analysis and tuning environment.

用于汞原子激光冷却的深紫外激光调谐和锁频系统

用于汞原子激光冷却的深紫外激光调谐和锁频系统

Electro-activated surface micropattern tuning for microinjection molded electrically conductive shape memory polyurethane composites

Shape memory polymers with surface micropatterns have seen rising demand for high value applications such as adjustable adherence surfaces, dynamic micro-geometries for cell culture studies and switchable information carriers. Recently, microinjection molding has emerged as an efficient way to manufacture devices which contain surface micro-features using a wide range of polymers with high accuracy. In this study, shape memory polyurethane–carbon nanotube composites were prepared by twin-screw melt extrusion and subsequently processed using microinjection molding to obtain components with surface micropatterns. Then an electro-activated surface micropattern tuning system was developed which could recover the original micropatterned surface of the components after a thermal deformation by applying a current which heats the component using resistive heating. In order to optimize the technique, three key areas were investigated in this work: conductivity of the microinjection molded microparts, the retention of shape memory micropatterns on the surface of microparts during annealing treatment, and the macroscopic area shrinkage of microparts after thermal treatment. It has been found that the electrical conductivity of microinjection molded parts is relatively low due to the high shear rates prevalent in the process. An annealing treatment improves the electrical conductivity by several orders of magnitude, but can be detrimental to the dimensional stability of the micropatterns, which depends significantly on the micro-injection molding parameters, especially the mold temperature. Increasing the mold temperature, melt temperature, injection speed and injection pressure result in better retention of the micropattern and improved dimension stability during annealing treatment. This work demonstrates the potential of electro-activated surface micropattern control for microinjection molded electrically conductive shape memory polymer composites, which could be a promising technology for a range of application areas including electro-adjustable adherence, information storage, and anti-counterfeiting technology.

2P1-C13 歩行支援のためのパラメータ調整システムの開発(福祉ロボティクス・メカトロニクス(3))

2P1-C13 歩行支援のためのパラメータ調整システムの開発(福祉ロボティクス・メカトロニクス(3))

OpenMPC: extended OpenMP for efficient programming and tuning on GPUs

General-purpose graphics processing units GPGPUs provide inexpensive, high performance platforms for compute-intensive applications. However, their programming complexity poses a significant challenge to developers. Even though the compute unified device architecture CUDA programming model offers better abstraction, developing efficient GPGPU code is still complex and error-prone. This paper proposes a directive-based, high-level programming model, called OpenMPC, which addresses both programmability and tunability issues on GPGPUs. We have developed a fully automatic compilation and user-assisted tuning system supporting OpenMPC. In addition to a range of compiler transformations and optimisations, the system includes tuning capabilities for generating, pruning, and navigating the search space of compilation variants. Evaluation using 14 applications shows that our system achieves 75% of the performance of the hand-coded CUDA programmes 92% if excluding one exceptional case.

A comparison of pluripotency and differentiation status of four mesenchymal adult stem cells

The self-renewal and differentiation status of a stem cell is very important in the applications concerning regenerative medicine. Proliferation capacity, differentiation potentials and epigenetic properties of stem cells differ between sources. Studies have shown the high potentials of stem cells in iPS reprogramming. To examine this; we have compared the stem-ness and differential potential of four adult stem cells from common sources. We show a correlation between pluripotency and differentiation status of each stem cell with available data on the reprogramming efficiency. Four human adult stem cells including, adipose tissue-mesenchymal stem cells (AT-MSC), bone marrow mesenchymal stem cells (BM-MSCs), nasal septum derived multipotent progenitors (NSP) and umbilical cord blood stem cells (USSCs) were isolated and characterized. The self- renewal and differentiation potentials of each stem cell were assessed. Stem-ness transcription factors and the propagation potentials of all cells were analyzed. Furthermore the differentiation potentials were evaluated using treatment with induction factors and specific MicroRNA profile. Real-time PCR results showed that our stem cells express innate differentiation factors, miR145 and Let7g, which regulate the stem-ness and also the reprogramming potentials of each stem cell. To complete our view, we compared the propagation and differentiation potentials by correlating the stem-ness gene expression with differentiation MicroRNAs, also the direct effect of these factors on reprogramming. Our results suggest that the potentials of adipose tissue stem cells for GMP (Good Manufacturing Practice) compliant starting material are adequate for clinical applications. Our results indicate a low risk potential for AT-MSCs as starting material for iPS production. Although let7g and mir145 are well known for their differentiation promoting effects, but function more of a fine tuning system between self-renewal and differentiation status.

A new pneumatic suspension system with independent stiffness and ride height tuning capabilities

This paper introduces a new pneumatic spring for vehicle suspension systems, allowing independent tuning of stiffness and ride height according to different vehicle operating conditions and driver preferences. The proposed pneumatic spring comprises a double-acting pneumatic cylinder, two accumulators and a tuning subsystem. This paper presents a detailed description of the pneumatic spring and its working principle. The mathematical model is established based on principles of thermo and fluid dynamics. An experimental setup has been designed and fabricated for testing and evaluating the proposed pneumatic spring. The analytical and experimental results confirm the capability of the new pneumatic spring system for independent tuning of stiffness and ride height. The mathematical model is verified and the capabilities of the pneumatic spring are further proved. It is concluded that this new pneumatic spring provides a more flexible suspension design alternative for meeting various conflicting suspension requirements for ride comfort and performance.

Sm@rtConfig: A context-aware runtime and tuning system using an aspect-oriented approach for data intensive engineering applications

Distributing the workload upon all available Processing Units (PUs) of a high-performance heterogeneous platform (e.g., PCs composed by CPU–GPUs) is a challenging task, since the execution cost of a task on distinct PUs is non-deterministic and affected by parameters not known a priori. This paper presents Sm@rtConfig, a context-aware runtime and tuning system based on a compromise between reducing the execution time of engineering applications and the cost of tasks' scheduling on CPU–GPUs' platforms. Using Model-Driven Engineering and Aspect Oriented Software Development, a high-level specification and implementation for Sm@rtConfig has been created, aiming at improving modularization and reuse in different applications. As case study, the simulation subsystem of a CFD application has been developed using the proposed approach. These system's tasks were designed considering only their functional concerns, whereas scheduling and other non-functional concerns are handled by Sm@rtConfig aspects, improving tasks modularity. Although Sm@rtConfig supports multiple PUs, in this case study, these tasks have been scheduled to execute on an platform composed by one CPU and one GPU. Experimental results show an overall performance gain of 21.77% in comparison to the static assignment of all tasks only to the GPU.

Evolutionary Tuning of Fuzzy Rule Base Systems for Nonlinear System Modelling and Control

Fuzzy systems generally works based on expert knowledge base. Fuzzy Expert knowledge base derived from the heuristic knowledge of experts or experience operators in the form of fuzzy control rules and membership functions (MFs). The major difficulties for design ing a fuzzy models and controllers are identify the optimized fuzzy rules and their corresponding shape, type and distribution of MFs. Moreover, the numbers of fuzzy control rules increases exponentially with the number of input output variables related to the control system. For this reason it is very difficult and time consuming for an expert to identify the complete rule set and shape of MFs for a complex control system having large number of input and output variables. In this paper, we propose a methodcalled evolutionary fuzzy system for tuning the parameters of fuzzy rules and adjust the shape of MFs through evolutionary algorithms in order to design a suitable and flexible fuzzy models and controller for complex systems. This paper also presents new flexible encoding method methods for evolutionary algorithms. In evolutionary fuzzy system, the evolutionary algorithms is adapted in two different ways Firstly, generating the optimal fuzzy rule sets including the number of rules inside it and secondly, selecting the optimum shape and distribution of MFs for the fuzzy control rules. In order to evaluate the validity and performance of the proposed approach we have designed a test strategy for the modeling and control of nonlinear systems. The simulation re sults show the effectiveness of our method and give better performance than existing fuzzy expert systems.

A Universal Adaptive Driving Scheme for Synchronous Rectification in LLC Resonant Converters

In this paper, a universal adaptive driving scheme for synchronous rectification (SR) is proposed. The drain to source voltage of the synchronous rectifier is sensed so that the paralleled body diode conduction is detected. Using the proposed SR driving scheme, the SR turn-OFF time is tuned to eliminate the body diode conduction. The SR gate driving signal can be tuned within all operating frequency regions. Moreover, a simple digital implementation is introduced. Compared with analog ones, it enables more intelligent and precise SR control, improving converter efficiency. For rapid prototyping purposes, the digital SR tuning system is realized in Cyclone III field-programmable gate array (FPGA).

KONSEP ÊMBAT DALAM KARAWITAN JAWA

Êmbat is one of the musical concept in Javanese gamelan music – karawitan Jawa. It is a kind of musical characteristic of a gamelan ensamble  which is generated by its interval structure – Jv. jangkah – of that gamelan. The only way to understand êmbat, one may investigate gamelan tuning system. Êmbat had been metioned in old Javanese manuscripts including Centhini and Wédhapradangga. Kunst and Hood also discussed êmbat in some extend, but the result does not quite fit to reality. This work aims to explain the concept of êmbat from the angle of the culture owner – Javanese.In order to explain the concept, this study has firstly to discover the concept of pitch in karawitan Jawa, secondly the tolerance of the limit in sifting tones , and finally approaching the main goal: the concept of êmbat it self. To reach the goal this studi conducted some simple experiments. Key words:structure of jangkah, tolerance of sifting notes, and êmbat