Intelligent and perceptual-based approach to musical instruments sound design

A novel, generic framework for musical instrument sound design is proposed. The framework uses an intelligent and perceptual based approach to address the two main problems in sound design - optimization of synthesis parameters and assessment of sound quality. A fuzzy model is used to capture and exploit knowledge of sound design from audio experts. A robust methodology, based on the ITU Perceptual Evaluation of Audio Quality (PEAQ) algorithm, is used for objective prediction of sound synthesis quality and sound quality assessment. The new framework makes it possible to automate the optimization of synthesis parameters. It also allows the designer to evaluate objectively, the perceptual impact of individual parameters on the final sound quality which is useful for benchmarking sound synthesis methods. The framework is generic and can be used for sound design for a wide range of musical instruments. We illustrate the use of the framework in pipe organ sound design. Results from this show that the new approach provides an important and useful alternative to existing methods.     

Using machine-learning methods for musical style modeling

The ability to construct a musical theory from examples presents a great intellectual challenge that, if successfully met, could foster a range of new creative applications. Inspired by this challenge, we sought to apply machine-learning methods to the problem of musical style modeling. Our work so far has produced examples of musical generation and applications to a computer-aided composition system. Machine learning consists of deriving a mathematical model, such as a set of stochastic rules, from a set of musical examples. The act of musical composition involves a highly structured mental process. Although it is complex and difficult to formalize, it is clearly far from being a random activity. Our research seeks to capture some of the regularity apparent in the composition process by using statistical and information theoretic tools to analyze musical pieces. The resulting models can be used for inference and prediction and, to a certain extent, to generate new works that imitate the style of the great masters.     

A special purpose digital system for musical instruction,composition, and performance

Language Resources and Evaluation -     

指令集仿真器的关键技术

为适应嵌入式系统开发中对指令集仿真器仿真速度的要求,提出一种改进的指令集仿真技术.该技术在现有的静态多核仿真器基础上引入指令预处理、动态译码缓存、多线程C函数生成和动态调度运行等技术,以实现对仿真器性能的优化.该技术已成功应用于中国科学院微电子所自主研发的IME-Diamond DSP处理器的多核指令集仿真器OPT-ISS中.实际应用程序测试结果表明,该技术在仿真速度提升方面有明显效果.     

Metrics for evaluating database selection techniques

The increasing availability of online databases and other information resources in digital libraries and on the World Wide Web has created the need for efficient and effective algorithms for selecting databases to search. A number of techniques have been proposed for query routing or database selection. We have developed a methodology and metrics that can be used to directly compare competing techniques. They can also be used to isolate factors that influence the performance of these techniques so that we can better understand performance issues. In this paper we describe the methodology we have used to examine the performance of database selection algorithms such as gGlOSS and CORI. In addition we develop the theory behind a “random” database selection algorithm and show how it can be used to help analyze the behavior of realistic database selection algorithms. This revised version was published online in August 2006 with corrections to the Cover Date.     

Knowledge discovery-based identification of musical pitches and instruments in polyphonic sounds

Pitch and timber detection methods applicable to monophonic digital signals are common. Conversely, successful detection of multiple pitches and timbers in polyphonic time-invariant music signals remains a challenge. A review of these methods, sometimes called “Blind Signal Separation”, is presented in this paper. We analyze how musically trained human listeners overcome resonance, noise, and overlapping signals to identify and isolate what instruments are playing and then what pitch each instrument is playing. The part of the instrument and pitch recognition system, presented in this paper, responsible for identifying the dominant instrument from a base signal uses temporal features proposed by Wieczorkowska [Slezak, D., Synak, P., Wieczorkowska, A., Wróblewski, J., 2002. Kdd-based approach to musical instrument sound recognition. Hacid, M.-S., Raś, Z.W., Zighed, D.A., Kodratoff, Y. (Eds.), Foundations of Intelligent Systems. Proceedings of 13th Symposium ISMIS 2002, Lyon, Franc 4519 Berlin, Heidelberg, pp. 28–36.] in addition to the standard 11 MPEG7 features. After retrieving a semantical match for that dominant instrument from the database, it creates a resulting foreign set of features to form a new synthetic basen signal which no longer bears the previously extracted dominant sound. The system may repeat this process until all recognizable dominant instruments are accounted for in the segment. The proposed methodology incorporates Knowledge Discovery, MPEG7 segmentation and Inverse Fourier Transforms.     

Computerized methods for X-ray-based small bone densitometry

Animal models have been widely used to correlate in vivo changes in bone mineral density (BMD) with changes in disease state of bone. In small animal models, e.g. the hindlimb suspension model of bone loss, a non-invasive assessment of BMD is required. X-ray radiography has been surpassed in some cases by quantitative computed tomography (QCT) and dual X-ray absorptiometry (DEXA) quantitation. However, there are drawbacks in using the computerized methods, especially for small animals. In this paper, we present image-processing algorithms to quantitatively determine bone area and mineral density in digitized radiographs. Image calibration is based on a calibration step wedge, and the algorithm automatically detects the steps and computes the calibration data. In addition, we demonstrate how the algorithm can accurately determine the cortical outline of the bone and provide reliable data and statistics for small animal studies. A downloadable implementation example for the popular NIH Image package is provided.     

利用Stencil建模及评估Intel IMCI vgather指令

Intel Xeon Phi协处理器的指令集IMCI引入了硬件实现的vgather指令,旨在帮助512位SIMD寄存器访问非连续内存地址上的数据。然而实验结果显示,vgather很有可能成为应用在Xeon Phi协处理器上关键的性能瓶颈之一。基于以上结论,针对vgather的性能建模可以帮助用户深入地掌握和理解Xeon Phi协处理器的性能特性。在实验方法上,本文方法与现存的通过程序段内嵌入汇编代码进行数据统计不同,使用PAPI等性能分析工具直接收集硬件计数器的统计结果,作为模型的实验数据。本文的性能模型基于AGI事件次数和根据VPU_DATA_READ次数估算得出的vgather所导致的平均延迟构建而成。该模型能够对Xeon Phi应用代码中由vgather所导致的总延迟进行预测。最终,为了验证模型预测的准确性,将该模型应用在三维7点stencil应用代码上,预测结果显示,vgather耗时占计算总耗时的约40%。再将该结果与利用intrinsics指令去除vgather后的计算耗时进行了对比验证,结果显示模型预测准确。基于上述结论,采用硬件计数器的统计结果在Xeon Phi协处理器上针对vgather构建了性能模型。同时,通过与其他平台的vgather对比,认为该模型也可以应用在同样具备vgather的Intel CPU处理器平台上。     

A system for evaluating the effect of keyboard design on force,posture, comfort,and productivity

The purpose of this study was to develop a system to determine the effectiveness of an alternative keyboard design which aimed to reduce fingertip force and awkward wrist postures. A prototype alphanumeric keyboard, adjustable in four ways, was developed for this study. Four measurements were chosen to determine the effectiveness of each keyboard configuration: fingertip impact force; wrist position; productivity; and comfort and ease of use. Fingertip force was measured using instrumented keys that had strain gauges located between the key cap and the key switch. Wrist position was measured using electronic goniometers attached to the forearms and hands of the test subjects. A computer program was developed to measure productivity, and a questionnaire based on the Borg rating scale was developed to measure comfort and ease of use. The system was tested to ensure its accuracy. Linearity, repeatability, strike position sensitivity, and natural frequency of the instrumented keycap assembly were assessed. Output of the electric goniometers was compared with readings on a manual goniometer to ensure the former's accuracy over the range of wrist angles expected during keyboard operations. Results of the validation indicated that the system is capable of measuring fingertip force and wrist angle accurately and repeatably. The system described in this paper is the first one that measures fingertip force, wrist position, productivity, and comfort and ease of use simultaneously.     

Stabilization techniques for spectral methods

We introduce a stabilized treatment of spectral methods. The condition number of the spectral systems is highly improved. Elliptic and biharmonic problems are considered. Suitable interpolants in the case of inhomogeneous Dirichlet boundary conditions are presented. For a direct solver the improvements with respect to rounding error propagation are numerically demonstrated.     

A computational study of heuristic and exact techniques for superblock instruction scheduling

Compilers perform instruction scheduling to improve the performance of code on modern computer architectures. Superblocks??a straight-line sequence of code with a single entry point and multiple possible exit points??are a commonly used scheduling region within compilers. Superblock scheduling is NP-complete, and is done suboptimally in production compilers using a greedy algorithm coupled with a heuristic. Recently, exact schedulers have also been proposed. In this paper, we perform an extensive computational study of heuristic and exact techniques for scheduling superblocks. Our study extends previous work in using a more realistic architectural model, in not assuming perfect profile information, and in systematically investigating the case where profile information is not available. Our experimental results show that heuristics can be brittle and what looks promising under idealized (but unrealistic) conditions may not be robust in practice. As well, for the case where profile information is not available, some methods clearly dominate. Notably, a much inferior method is deployed in at least one existing compiler.     

Computerized tests and time: measuring,limiting and providing visual cues for response time in on-line questioning

Abstract

It is possible and attractive to incorporate time-related measures and techniques in on-line computerized testing systems. However, is it advisable? This study focuses on the measurement of response time, the solicitation of speed, the limitation of allotted time and the provision of on-line visual cues for the passage of time (on-screen hourglass). An experiment was conducted using a standard general knowledge component of a psychometric test; 198 students completed an on-line psychometric test under several time-related experimental conditions. Findings encourage further use of time-related techniques. Positive correlations were found between performance as measured by accuracy in response and speed measures. Time-limiting procedures allowed savings of almost 50% of examinee and examiner's time, without diminishing score reliability. The reliability of the speed measures is at least as high as the reliability of accuracy measures. Examinees' stress was not affected, but intersubjective attitudes are a problem for the incorporation of time-related measures. Finally, while accuracy scores are biased by demographics, speed measures seem to be independent of experience in using computers, gender, age and education.     

Computerized tests and time: measuring, limiting and providing visual cues for response time in on-line questioning

It is possible and attractive to incorporate time-related measures and techniques in on-line computerized testing systems. However, is it advisable? This study focuses on the measurement of response time, the solicitation of speed, the limitation of allotted time and the provision of on-line visual cues for the passage of time (on-screen hourglass). An experiment was conducted using a standard general knowledge component of a psychometric test; 198 students completed an on-line psychometric test under several time-related experimental conditions. Findings encourage further use of time-related techniques. Positive correlations were found between performance as measured by accuracy in response and speed measures. Time-limiting procedures allowed savings of almost 50% of examinee and examiner's time, without diminishing score reliability. The reliability of the speed measures is at least as high as the reliability of accuracy measures. Examinees' stress was not affected, but intersubjective attitudes are a problem for the incorporation of time-related measures. Finally, while accuracy scores are biased by demographics, speed measures seem to be independent of experience in using computers, gender, age and education.     

A framework for evaluating specification methods for reactivesystems-experience report

Numerous formal specification methods for reactive systems have been proposed in the literature. Because the significant differences between the methods are hard to determine, choosing the best method for a particular application can be difficult. We have applied several different methods, including Modechart, VFSM, ESTEREL, Basic LOTOS, Z, SDL, and C, to an application problem encountered in the design of software for AT&T's 5ESS telephone switching system. We have developed a set of criteria for evaluating and comparing the different specification methods. We argue that the evaluation of a method must take into account not only academic concerns, but also the maturity of the method, its compatibility with the existing software development process and system execution environment, and its suitability for the chosen application domain     

Adaptive instruction dispatching techniques for Simultaneous Multi-Threading (SMT) processors

Simultaneous Multi-Threading (SMT) provides a technique to improve resource utilization ability by sharing key data-path components among multiple independent threads. When critical resources are shared by multiple threads, effective use of these resources proves to be the most important factor in fully exploiting the system potential. Transient behaviors of various threads in terms of their execution parallelism can easily affect utilization efficiency of these shared resources. To commit more resources to threads that are more active allows for better resource utilization and thus higher throughput. In this paper, we propose a real-time dynamic scheduler for the SMT which dispatches instructions from threads based on thread-activeness information gathered in real time and dynamically adjusts dispatching priorities among threads accordingly. An extensive simulation shows a significant gain in system throughput by this technique. The performance of the proposed dispatching technique is evaluated on different workload mixtures created based on instruction-level parallelism available in each thread. An average of 6.5% and maximum of 15% performance improvement is observed with the proposed dispatching technique.     

YHFT-DX高性能DSP指令控制流水线设计与优化

YHFT-DX是国防科技大学设计的一款高性能定点DSP。论文设计并实现了YHFT-DX指令控制流水线,提出了在YHFT-DX 超长指令字结构中跨取指包边界派发和指令预取的方法,有效提升了流水线的性能。对指令流水线进行了高频结构优化,将派发部件的关键路径延时压缩40%,满足了600 MHz频率的设计目标。     

结合的指令调度与寄存器分配技术

提出了很多结合技术使得指令调度与寄存器分配之间进行一些信息交互,在没有引入过多溢出代码的情况下提高了指令级并行度,从而提高了性能。按照算法的特征分类介绍了几种影响力较大的算法,同时作了简单的评价和效果比较,最后介绍了有关指令调度和寄存器分配结合的一些新方向。