Fast Performance Modeling across Different Database Versions Using Partitioned Co-Kriging

Database systems have a large number of configuration parameters that control functional and non-functional properties (e.g., performance and cost). Different configurations may lead to different performance values. To understand and predict the effect of configuration parameters on system performance, several learning-based strategies have been recently proposed. However, existing approaches usually assume a fixed database version such that learning has to be repeated once the database version changes. Repeating measurement and learning for each version is expensive and often practically infeasible. Instead, we propose the Partitioned Co-Kriging (PCK) approach that transfers knowledge from an older database version (source domain) to learn a reliable performance prediction model fast for a newer database version (target domain). Our method is based on the key observations that performance responses typically exhibit similarities across different database versions. We conducted extensive experiments under 5 different database systems with different versions to demonstrate the superiority of PCK. Experimental results show that PCK outperforms six state-of-the-art baseline algorithms in terms of prediction accuracy and measurement effort.

A two-zone sound field reproduction based on the region energy control

Multizone sound field reproduction aims to create different acoustical environments in regions without physical isolation. For a real reproduction system, it is always expected to improve system performance and reduce measurement effort. In this paper, a two-zone sound field reproduction is investigated with a proposed region control method. Conventional multipoint method only controls sound field at limited number of measurement points. However, the proposed method tries to control the sound field energy over the whole region. Considering the system's diverse work environment, different interpolation methods are applied in the proposed method. Simulations are conducted under free field and reverberation condition in order to deeply compare with conventional method and another harmonic domain method. Simulation results show that the proposed method achieves better performance than the conventional multipoint method in free field and reverberant environment. On the other hand, the region control method proposed in this paper is free from microphone array geometry requirement, which means the method is more convenient for the practical application.

Ranking Biomarkers of Aging by Citation Profiling and Effort Scoring

Aging affects most living organisms and includes the processes that reduce health and survival. The chronological and the biological age of individuals can differ remarkably, and there is a lack of reliable biomarkers to monitor the consequences of aging. In this review we give an overview of commonly mentioned and frequently used potential aging-related biomarkers. We were interested in biomarkers of aging in general and in biomarkers related to cellular senescence in particular. To answer the question whether a biological feature is relevant as a potential biomarker of aging or senescence in the scientific community we used the PICO strategy known from evidence-based medicine. We introduced two scoring systems, aimed at reflecting biomarker relevance and measurement effort, which can be used to support study designs in both clinical and research settings.

Simple Bayesian Algorithms for Best-Arm Identification

This paper considers the optimal adaptive allocation of measurement effort for identifying the best among a finite set of options or designs. An experimenter sequentially chooses designs to measure and observes noisy signals of their quality with the goal of confidently identifying the best design after a small number of measurements. Just as the multiarmed bandit problem crystallizes the tradeoff between exploration and exploitation, this “pure exploration” variant crystallizes the challenge of rapidly gathering information before committing to a final decision. The paper proposes several simple Bayesian algorithms for allocating measurement effort and, by characterizing fundamental asymptotic limits on the performance of any algorithm, formalizes a sense in which these seemingly naive algorithms are the best possible.

Binaural Rendering with Measured Room Responses: First-Order Ambisonic Microphone vs. Dummy Head

To improve the limited degree of immersion of static binaural rendering for headphones, an increased measurement effort to obtain multiple-orientation binaural room impulse responses (MOBRIRs) is reasonable and enables dynamic variable-orientation rendering. We investigate the perceptual characteristics of dynamic rendering from MOBRIRs and test for the required angular resolution. Our first listening experiment shows that a resolution between 15 ∘ and 30 ∘ is sufficient to accomplish binaural rendering of high quality, regarding timbre, spatial mapping, and continuity. A more versatile alternative considers the separation of the room-dependent (RIR) from the listener-dependent head-related (HRIR) parts, and an efficient implementation thereof involves the measurement of a first-order Ambisonic RIR (ARIR) with a tetrahedral microphone. A resolution-enhanced ARIR can be obtained by an Ambisonic spatial decomposition method (ASDM) utilizing instantaneous direction of arrival estimation. ASDM permits dynamic rendering in higher-order Ambisonics, with the flexibility to render either using dummy-head or individualized HRIRs. Our comparative second listening experiment shows that 5th-order ASDM outperforms the MOBRIR rendering with resolutions coarser than 30 ∘ for all tested perceptual aspects. Both listening experiments are based on BRIRs and ARIRs measured in a studio environment.

Simulation study with minimised additional data requirements to analyse control and operation of WWTP Dorsten, Germany

This paper describes a method to decrease the additional measurement effort during a model calibration/verification to create reliable models for plant optimisation. The method is based on the deterministic processes creating the dry weather inflow to municipal treatment plants, which can be described by a simple influent composition model. This method was applied to two wastewater treatment plants of Lippeverband and the usability is indicated by the good correlation between routine online effluent measurements and simulation results. This paper presents one of these applications, the case study WWTP Dorsten. The resulting model is used to analyse the current plant performance, to analyse bottlenecks and to develop future improvements of operation and control of this plant. A selection of control options is demonstrated.

An efficient monitoring concept with control charts for on-line sensors

A monitoring concept for on-line sensors will be discussed which helps the WWTP staff to detect drift-, shift- and outlier effects as well as unsatisfactory calibration curves. The approach is based on the analysis of comparative measurements between the sensor and a reference method. It combines statistical analysis such as control charts and regression analysis with decision support rules. The combination of two different detection levels in the selected Shewhart control charts with additional criteria allows one to detect ‘out-of-control’ situations early with an optimized measurement effort. Beside the statistical analysis the concept supports the operator with a graphical analysis to monitor the accuracy of on-line measurements efficiently. The widely applicable monitoring concept will be illustrated with examples for an ion-sensitive NH4+- and a MLSS-sensor.

Measuring and modeling surface area of ponderosa pine needles

Two methods for needle area estimation were compared for Pinus ponderosa Dougl. ex P. Laws. & C. Laws., and models were developed to predict total, projected, and abaxial areas. Areas of needles were determined by using video capture – image analysis procedures (VCIA) and by direct measurement of needle sections. VCIA area estimates were 40–60% less than abaxial areas determined from direct measurements. Allometric models fit to VCIA area and mean needle width (Wv) explained 96% of the variation in measured sample areas; models omitting Wv explained 91% of the variation. Predictions for independently collected validation data were somewhat poorer and slightly biased but had similar residual patterns. Allometric models fit to midneedle width and total needle length explained 99% of the variation in directly measured needle areas, with root mean square error equal to 2% of the mean measured areas. Results were similar for the validation data. For both models, final parameters were estimated from the combined data. It is shown that fascicle areas estimated from predictions for the middle-sized needles are nearly as accurate as estimates based on measurements for entire fascicles. Direct measurement of needles is more portable than VCIA and provides more accurate needle area estimates with less measurement effort.

An Innovative Approach to Increase the Accuracy of Multi-Axis Machines for Process-Intermittent Inspection

A method for enhancing the effectiveness and robustness of process-intermittent inspection is presented. The method is developed first using mathematical models and measurements closely related to the real parts, thus reducing the uncertainty in both the error estimation and compensation for multi-axis machines. A predictive search algorithm is then developed to identify the minimum number of appropriate measuring points (with respect to the designated tolerance) for arbitrarily shaped manufacturing parts. The identified measuring points are robust in that they least sensitive to uncertainties in measurement and modeling. The search algorithm uses computer simulation with information obtained from previous measurements. Consequently, the measurement effort involved in error modeling has been greatly reduced. The error model derived from the method can be used to correct the process-intermittent probing data for a more accurate assessment of workpiece dimensions. Although the method is designed for general application in multi-axis machines (i.e., machine tools, robots, and coordinate measuring machines), this paper focuses on the specific application of a machining center. Experimental results demonstrate the effectiveness of the error modeling method for accuracy improvement of the machining center for process-intermittent inspection.