Improve Identification Accuracy Research Articles

Detection of the A189G mtDNA heteroplasmic mutation in relation to age in modern and ancient bones

The aim of this study was to demonstrate the presence of the A189G age-related point mutation on DNA extracted from bone. For this, a peptide nucleic acid (PNA)/DNA sequencing method which can determine an age threshold for the appearance of the mutation was used. Initially, work was done in muscle tissue in order to evaluate the sensitivity of the technique and afterwards in bone samples from the same individuals. This method was also applied to ancient bones from six well-preserved skeletal remains. The mutation was invariably found in muscle, and at a rate of up to 20% in individuals over 60 years old. In modern bones, the mutation was detected in individuals aged 38 years old or more, at a rate of up to 1%, but its occurrence was not systematic (only four out of ten of the individuals over 50 years old carried the heteroplasmy). For ancient bones, the mutation was also found in the oldest individuals according to osteologic markers. The study of this type of age-related mutation and a more complete understanding of its manifestation has potentially useful applications. Combined with traditional age markers, it could improve identification accuracy in forensic cases or in anthropological studies of ancient populations.

Effects of learners’ L2 proficiency and acoustic/semantic contexts of stimuli on the phoneme identification training

Former studies investigated that word recognition by L2 learners is affected by both acoustic and semantic contexts [Rothwell and Akahane-Yamada, J. Acout. Soc. Am. 112, 2386 (2002)]. It was also shown that these two context effects lead to different achievement in perception training [Ikuma and Akahane-Yamada, J. Acout. Soc. Am. 115, 2393 (2004)]. In this study, native speakers of Japanese were trained to identify English /r/ and /l/ within words or sentences. L2 proficiency level for each trainee was also measured by a short written test regarding vocabulary and grammar. Results showed that training with semantically contextual stimuli improved the identification accuracy for stimuli with semantically contextual cues, but not for stimuli without semantic cues. Furthermore, the L2 proficiency level correlated only with the improvement in identification accuracy of target phonemes embedded in the semantically contextual sentences. These results suggest that L2 learners tend to use semantic cues rather than difficult acoustic cues. However, semantic context may moderate the effect of auditory perception training. Thus, training with semantically neutral stimulus is necessary to improve perception ability even for high proficiency level learners. [Work supported by JSPS.]

Effects of exposure and training on perception of Japanese length contrasts by English listeners

Native English listeners are known to have difficulty distinguishing Japanese words that contrast in phonemic length, often realized as a contrast in vowel or consonant duration. The present study reports results from a series of experiments investigating the extent to which English listeners’ perception of such length contrasts can be modified with exposure to Japanese and with perceptual identification training. Listeners were trained in a minimal‐pair identification paradigm with feedback. A pretest and posttest were also administered, using natural tokens of Japanese words containing various vowel and consonant length contrasts, produced in isolation and in a carrier sentence, at three speaking rates, and by multiple talkers. Results indicated that exposure and perceptual training substantially improved identification accuracy. Even though listeners were trained to identify words contrasting in vowel length only, performance also improved for other contrast types. Furthermore, speaking rate strongly a...

3-2 人物識別方式での信頼性の向上における電子透かしの利用法の検討(第3部門 人物・顔の認識とその応用)

3-2 人物識別方式での信頼性の向上における電子透かしの利用法の検討(第3部門 人物・顔の認識とその応用)

Study of improving identification accuracy of carbon nanotube film cathode gas sensor

Ionization gas sensors need to combine with chromatograph and mass spectrograph to separate gas mixture; this results in huge, bulky architecture, high power consumption and risky high-voltage operation. Here we proposed using two-sensor array composed of two carbon-nanotube film cathode gas sensors with different gaps and using multi-information fusion technology to directly and precisely identify the gas mixture at atmospheric pressure without separating the mixture. Two-sensor array with different gaps were used, and experiments were conducted to obtain the original patterns (OPs) of the two sensors, viz. the relationship between the breakdown voltages and the gas concentrations of the two-gas mixture. The interpolation technology was used to improve OPs, and the neural network technology was used to precisely identify the two components without separating the mixture. This novel method greatly improved the performance of the gas sensor, and can be used to identify n-gas mixture ( n > 2) with n-sensor array.

Bioacoustic monitoring of forest songbirds: interpreter variability and effects of configuration and digital processing methods in the laboratory

Omnidirectional bioacoustic recording systems offer the ability to record forest songbirds in the field by technical staff, and then interpret the recordings later in the laboratory by skilled interpreters. Among several advantages to this approach are the ability to estimate variance among interpreters, obtain a permanent archival record of the point count, reduce costs by using regular field crews to collect data vs. those skilled in bird identification, and remove impediments to breeding bird surveys due to lack of available skilled birders. In this study we first evaluated the effects of microphone configuration and digital processing methods on the quality and effectiveness of the recordings, and then evaluated how consistently skilled birders interpreted the same songbird recordings collected under a mix of environmental conditions, and related this to the commonness of the species. At the time of this evaluation, the most cost-effective configuration of the bioacoustic monitoring system included use of a 180°/180° microphone combination, a minidisc digital recording system, analog transfer of the sound data via a digital soundcard, post-processing amplification of the signal, and data storage in an .MP3 format. This combination maintains high sound fidelity while minimizing both expense and data storage requirements. As recording device technology improves, the direct storage and digital transfer of .WAV format files will be the preferred and most effective recording option. Despite noisy conditions due to wind and other ambient sounds for many of the recordings, interpreters showed a high level of similarity in species identification and enumeration for the 34 most abundant species. Standardized coefficient of variance increased sharply when species had fewer than 10 occurrences, suggesting that birders are more variable in their identification of rare or uncommon species. Desktop identification systems that include type specimens of spectrographic signature and sound clips to aid interpreters could improve identification accuracy of rarer species.

有限語長データに基づくシステム同定

For system identification of continuous-time plants, we commonly use digital data converted from analog signals. Since digital variables are of finite wordlengths, they contain quantization errors. Such errors may deteriorate identification accuracy significantly, especially in the case of mechanical systems where large movement and precise positioning are required. To overcome this problem, the present paper proposes to estimate the quantization errors and thus true analog sampled signals to improve identification accuracy. Estimation of quantization errors and system identification are carried out simultaneously.

The role of spectral asynchrony in the identification of spectrally smeared environmental sounds

This study examined possible contributions of spectral asynchrony caused by the differences in filter group delays across channels to the previously reported decline in identification accuracy of several spectrally smeared environmental sounds [V. Shafiro, J. J. Jenkins, and W. Strange, J. Acoust. Soc. Am, 113(4), 2326–2327 (2003)]. As in the previous experiment, stimuli were obtained by processing environmental sounds through a noise-based vocoder with a varying number of frequency channels. In the present experiment, however, the group delays were held constant across channels, while the overall frequency response of the filters closely resembled the earlier one. Listeners were instructed to identify the most likely source of each sound by selecting it from 60 possible response options. Results indicated that identification accuracy improved for some environmental sounds, while it worsened for other sounds. Overall, there was little improvement in identification accuracy across channels. These findings are interpreted as reflecting the limitations in signal-processing parameters and undesirable processing artifacts. Preliminary results of a different signal-processing method that maintains a constant group delay and uses linear frequency intervals for individual channels indicate a greater improvement in identification accuracy.

Moving force identification from bending moment responses of bridge

Moving force identification is a very important inverse problem in structural dynamics. Most of the identification methods are eventually converted to a linear algebraic equation set. Different ways to solve the equation set may lead to solutions with completely different levels of accuracy. Based on the measured bending moment responses of the bridge made in laboratory, this paper presented the time domain method (TDM) and frequency-time domain method (FTDM) for identifying the two moving wheel loads of a vehicle moving across a bridge. Directly calculating pseudo-inverse (PI) matrix and using the singular value decomposition (SVD) technique are adopted as means for solving the over-determined system equation in the TDM and FTDM. The effects of bridge and vehicle parameters on the TDM and FTDM are also investigated. Assessment results show that the SVD technique can effectively improve identification accuracy when using the TDM and FTDM, particularly in the case of the FTDM. This improved accuracy makes the TDM and FTDM more feasible and acceptable as methods for moving force identification.

Particles for multiplexed analysis in solution: detection and identification of striped metallic particles using optical microscopy.

In this report, we present data demonstrating that cylindrical metallic particles, with various submicrometer striping patterns, may be readily distinguished in an optical microscope. Accurate particle identification is discussed relative to synthesis reproducibility and the limitations of optical microscopes. Results from a library of these particles, of which over 100 different striping patterns have been produced, are presented. For these particles, made with Au and Ag stripes, more than 70 patterns may be identified with greater than 90% accuracy. The ability to chemically modify the surface of these particles, making them useful for bioanalytical measurements, is also demonstrated. Finally, we discuss improvements in our manufacturing and identification processes that will lead to both larger numbers of striping patterns and improved identification accuracy.

109 画像処理を用いたはりのパラメータ同定 : 第4報、同定精度の向上および計算時間の短縮(OS10 振動ならびに衝撃解析・最適設計・モニタリング)

109 画像処理を用いたはりのパラメータ同定 : 第4報、同定精度の向上および計算時間の短縮(OS10 振動ならびに衝撃解析・最適設計・モニタリング)

Parameter Identification of Beam Using Image Processing. 4th Report. Improvement in Identification Accuracy and Calculation Time.

We have already proposed the techniques to identify the parameters and to detect a small crack in the cantilever beam using the image processing. In this paper, we intend to improve an accuracy and to reduce the calculation time in our proposed techniques. By optimizing the location of nodes in the Spline smoothing, we could reduce the error in the image data and get more precise deflection data of the beam. The time consuming part in the damage detection program using the simulated annealing technique was the FEM calculation of the deflection of the beam. After introducing the nonlinear but exact model of the beam element into the calculation of the beam deflection, the significant reduction of the calculation time was achieved in this paper.

Impulse Response Model Identification in the Case of a Multi-Period ZOH Input

This paper considers the problem of impulse response identification for a linear sampled-data system where the input signal is held constantly within a multiple of the sampling period of the output signal. To improve identification accuracy, this paper proposes a new identification approach by employing the Haar scaling and wavelet functions. At first, we point out that the discrete-time impulse response of a linear system with zero-order hold (ZOH) input is actually the piecewise-constant approximation of the continuous-time impulse response. Based on the close relation between piecewise-constant approximation with Haar scaling and wavelet functions, a hierarchical identification procedure is proposed which identifies the system impulse response from a coarse resolution level to a fine resolution level successively. At each resolution level, the BIC is utilized to determine the length of the decomposed impulse response in the corresponding subspace, so that some redundant parameters in the high frequency-domain which are sensitive to the noise effects are discarded. Since the identified impulse response model is not smooth when it is represented by some Haar scaling functions of different widths, we can replace each Haar scaling function in the preidentified impulse response model by a Gaussian basis function with corresponding position and width. Then an improved identification method is also proposed to achieve smooth continuous-time impulse response model from sampled data. It is shown through simulation study that the proposed methods yield accurate estimate of the impulse response even in the ill-conditioned cases.

Modulation identification of digital signals by the wavelet transform

There is a need, for example in electronic surveillance, to determine the modulation type of an incoming signal. The use of the wavelet transform for modulation identification of digital signals is described. The wavelet transform can effectively extract the transient characteristics in a digital communication signal, yielding distinct patterns for simple identification. Three identifiers for classifying PSK and FSK, M-ary PSK and M-ary FSK are considered. Statistics for hypothesis testing are derived. When the carrier-to-noise ratio is low, the symbol period and synchronisation time are needed to improve identification accuracy. A method for estimating them from the wavelet transform coefficients is included. The performance of the identifier is investigated through simulations.

ハールウェーブレットによるインパルス応答の同定精度の向上

ハールウェーブレットによるインパルス応答の同定精度の向上

Factors Associated with Behavioral Competence at School Among Young Boys from Multi-Problem Low-Income Families

Factors associated with school behavioral competence at 72 months were investigated in a sample of at-risk boys followed longitudinally from 18 months. Boys were at risk for developing behavior problems due to early exposure to sociodemographic and family-environmental stressors associated with low-income urban living. Research findings: Of child protective factors investigated, main effects were found for intelligence, mother-reported emotionality and sociability, and observed likability in relation to teacher-reported behavior problems, and results were generally consistent across type of risk. In only one instance did the effect of a protective factor depend on the level of risk. Furthermore, a cumulative measure of protective factors was strongly predictive of child behavior problems and was a better predictor than cumulative risk measures. Observed infant emotionality, child physical attractiveness, and children's self-perceptions of being pro-social or aggressive and fearless were essentially unrelated to behavioral outcome. Mother-reported child emotionality mediated both the relation between mother-reported infant emotionality and teacher-reported internalizing problems, and the relation between observed likability and teacher-reported externalizing problems. Practice/Policy: Clinical implications concern improved identification accuracy of at-risk children who should be targeted for intervention, and forms that intervention should take.

A key for freshwater invertebrates using fuzzy logic.

This paper summarizes a biological key using a fuzzy logic expert system. This approach allows the user to make some errors, be uncertain about some answers and not answer questions if unsure, but have an opportunity to identify unknown specimens correctly. This approach was adopted in order to develop a 'forgiving' key for users with little or no prior knowledge of identification. The system was implemented using a multi-media expert system builder, 'Matcher', operating in a Microsoft Windows environment. The paper reports the design issues for a key to identify freshwater invertebrates to family level and describes the types of questions used within the key, the fuzzy inference engine, the structure of the system and the methodology adopted for testing it. Following this, an empirical test is reported of the hypothesis that a fuzzy logic expert system can improve identification accuracy for a sample of intended users. Finally, the discussion considers the practicalities of using such a system as an aid to organism identification.

Dynamic cues in vowel identification: A training study.

The importance of dynamic formant information for vowel identification has been shown by several studies in recent years. Using sine‐wave vowel analogs, Neel and Kewley‐Port [J. Acoust. Soc. Am. 96, 3284(A) (1994)] demonstrated that vowel duration is an important cue for vowel identity and that dynamic formant information is more effective when duration cues are absent. However, because identification rates for sine‐wave stimuli were low, a training study was conducted to determine the impact of training on the effectiveness of dynamic formant and duration cues for vowel identification. Sine‐wave stimuli consisted of two tones representing F1 and F2 from 10 vowels produced by a female speaker. Four types of stimuli were constructed by varying two factors: (1) dynamic versus static formants and (2) appropriate versus fixed vowel duration. Listeners were trained to criterion on one set of stimuli and were tested on another. Training significantly improved identification accuracy. In comparison to performance on static formant tokens, listeners were more accurate in identification and improved more from baseline to test when dynamic formant cues were present. Listeners also showed an identification advantage when duration cues were available. [Research supported by NIHDCD Research Grant No. DC‐02229.]

Perceptual separation of simultaneous vowels: Within and across-formant grouping by F

Six experiments explored why the identification of the two members of a pair of diotic, simultaneous, steady-state vowels improves with a difference in fundamental frequency (delta F0). Experiment 1 confirmed earlier reports that a delta F0 improves identification of 200-ms but not 50-ms duration "double vowels"; identification improves up to 1 semitone delta F0 and then asymptotes. In such stimuli, all the formants of a given vowel are excited by the same F0, providing listeners with a potential grouping cue. Subsequent experiments asked whether the improvement in identification with delta F0 for the longer vowels was due to listeners using the consistent F0 within each vowel of a pair to group formants appropriately. Individual vowels were synthesized with a different F0 in the region of the first formant peak from in the region of the higher formant peaks. Such vowels were then paired so that the first formant of one vowel bore the same F0 as the higher formants of the other vowel. These across-formant inconsistencies in F0 did not substantially reduce the previous improvement in identification rates with increasing delta F0's of up to 4 semitones (experiment 2). The subjects' improvement with increasing delta F0 in the inconsistent condition was not produced by identifying vowels on the basis of information in the first-formant or higher-formant regions alone, since stimuli which contained either of these regions in isolation were difficult for subjects to identify. In addition, the inconsistent condition did produce poorer identification for larger delta F0's (experiment 3). The improvement in identification with delta F0 found for the inconsistent stimuli persisted when the delta F0 between vowel pairs was confined to the first formant region (experiment 4) but not when it was confined to the higher formants (experiment 6). The results replicate at different overall presentation levels (experiment 5). The experiments show that at small delta F0's only the first-formant region contributes to improvements in identification accuracy, whereas with larger delta F0's the higher formant region may also contribute. This difference may be related to other results that demonstrate the superiority of resolved rather than unresolved harmonics in coding pitch.

Evaluation of the Autoscan Walkaway system for rapid identification and susceptibility testing of gram-negative bacilli.

We evaluated the performance of the Autoscan Walkaway (W/A) system (MicroScan, Sacramento, Calif.) in conjunction with the fluorometric Neg Combo panels for rapid identification and susceptibility testing of gram-negative bacilli. Fermentative and nonfermentative gram-negative bacilli were tested in parallel with the W/A system and the Cathra Repliscan replicator (C/R) system (Cathra, St. Paul, Minn.). Conventional biochemical testing and agar dilution testing were used to resolve the identification and susceptibility testing discrepancies. Of 495 clinical isolates tested, 445 (90%) were correctly identified by the W/A system and 483 (98%) were correctly identified by the C/R system. Repeat testing by using updated versions of the W/A system's computer identification software failed to demonstrate improved identification accuracy. For susceptibility testing, the W/A system demonstrated 5.6% total interpretative category errors, including only 0.9% major and very major errors. The comparative C/R system produced only 1% errors overall, including 0.2% major and very major errors. Although the W/A system is highly automated and is capable of producing results rapidly, our findings suggest that additional identification and susceptibility testing refinements are needed before the system will be suitable for routine use.