Anisotropy-based performance analysis of linear discrete time invariant control systems

The anisotropic norm of a linear discrete-time-invariant system measures system output sensitivity to stationary Gaussian input disturbances of bounded mean anisotropy. Mean anisotropy characterizes the degree of predictability (or colouredness) and spatial non-roundness of the noise. The anisotropic norm falls between the H-2 and H-infinity norms and accommodates their loss of performance when the probability structure of input disturbances is not exactly known. This paper develops a method for numerical computation of the anisotropic norm which involves linked Riccati and Lyapunov equations and an associated special type equation.

A multidimensional approach to the group cohesion-group performance relationship

This study (a) examined the multidimensionality of both group cohesion and group performance, (b) investigated the relationship between group-level task and social cohesion and group effectiveness, and (c) examined the longitudinal changes in cohesion and performance and the direction of effect between cohesion and performance. First, the authors hypothesized that both task and social cohesion would predict positively all dimensions of group performance. Second, that a stronger relationship would be observed between task cohesion and task effectiveness and between social cohesion and system viability. Third, that all dimensions of cohesion and performance would increase over time. Finally, that cohesion would be both the antecedent and the consequence of performance but that the performance-cohesion relationship would be stronger than the cohesion-performance relationship. Results supported the hypothesized one-to-one relationship between specific dimensions of group cohesion and group performance. Task cohesion was the sole predictor of self-rated performance at both Time 1 and Time 2, whereas social cohesion was the only predictor of system viability at Time 1 and the stronger predictor at Time 2. Social cohesion at Time 2 predicted performance on group task. However, no longitudinal changes were found in cohesion or performance. Finally, group cohesion was found to be the antecedent, but not the consequence, of group performance.

A review of the impact of education and prior experience on new venture performance

The importance of education and experience to the successful performance of new firms is well recognized both by management practitioners and academics. Yet empirical research to support the significance of this relationship is inconclusive. This paper discusses theories describing the relationship between education and experience and firm performance. It also analyses and classifies the differing measures of performance, education and experience, and compares the results of multiple studies undertaken between 1977 and 2000. Possible reasons for conflicting results are identified, such as lack of sound theoretical bases that relate education and experience to performance, varying definitions of the key variables and the diversity of measures used. Finally, a framework is developed that incorporates variables that interact with experience and education to influence new venture performance.

Moderating effect of ear preference on personality in the prediction of sales performance

This study examined the relationship between ear preference, personality, and performance ratings on 203 telesales staff. Social desirability scores were a significant predictor of two relatively independent sets of supervisor ratings (actual performance and developmental potential) in interaction with ear preference. It was found that the social desirability scale was a significant positive predictor for staff preferring a right ear headset, but a negative predictor for staff preferring a left ear headset. These results were interpreted in terms of different strategies used to achieve successful sales.

Unagi-sentences in Japanese and mutual knowledge

This paper examines the so-called ’Unagi-sentence‘ in Japanese. So far, it has been taken for granted that the Unagi-sentence is incomplete syntactically and/or semantically. Because its structure apparently neither provides a fully-fledged semantic meaning, nor furnishes a plausible syntactic pattern (such as ‘subject-predicate‘), a number of previous works have considered the Unagi-sentence to be elliptic, and consequently reconstructed it as a complete sentence or established intermediate structures to account for its grammatical form. Other researchers have not used elliptic solutions, but sought to discover logical connections between the parts of the Unagi-sentence themselves. As a result, fixing their entire attention on the internal structure of the Unagi-sentence, these researchers inevitably needed to establish hypothetical constructs in order to explain the structure of the Unagi-sentence. The present author believes that the Unagi-sentence is neither incomplete nor a result of some hypothetical processes. The Unagi-sentence stands on its own as a complete utterance. It is basically an NP utterance which can be expanded to the form NP1 wa + NP2 da and its variations. The occurrence of the Unagi-sentence depends heavily on a presupposed context and its pragmatic features, without which the Unagi-sentence cannot exist. It is these features that the present article seeks to elucidate.

Diagnostic performance of Antineutrophil Cytoplasmic Antibody tests for Idiopathic Vasculitides: Metaanalysis with a focus on antimyeloperoxidase antibodies

Objective. The diagnostic value of tests for antimyeloperoxidase antibodies (anti-MPO) for systemic vasculitis is less established than that for cytoplasmic antineutrophil cytoplasmic antibody (cANCA)/antiproteinase 3 antibodies (anti-PR3). Controversy exists regarding the optimal utilization of indirect immunofluorescence (IIF) ANCA testing versus antigen-specific ANCA testing. To summarize the pertinent data, we conducted a metaanalysis examining the diagnostic value of ANCA testing systems that include assays for anti-MPO. Methods. We performed a structured Medline search and reference list review. Target articles in the search strategy were those reporting the diagnostic value of immunoassays for anti-MPO for the spectrum of systemic necrotizing vasculitides that includes Wegener's granulomatosis, microscopic polyangiitis, the Churg-Strauss syndrome, and isolated pauci-immune necrotizing or crescentic glomerulonephritis, regardless of other types of ANCA tests. Inclusion criteria required specification of a consecutive or random patient selection method and the use of acceptable criteria for the diagnosis of vasculitis exclusive of ANCA test results. Weighted pooled summary estimates of sensitivity and specificity were calculated for anti-MPO alone, anti-MPO + perinuclear ANCA (pANCA), and anti-MPO/pANCA + anti-PR3/cANCA. Results. Of 457 articles reviewed, only 7 met the selection criteria. Summary estimates of sensitivity and specificity (against disease controls only) of assays for anti-MPO for the diagnosis of systemic necrotizing vasculitides were 37.1% (confidence interval 26.6% to 47.6%) and 96.3% (CI 94.1% to 98.5%), respectively. When the pANCA pattern by IIF was combined with anti-MPO testing, the specificity improved to 99.4%, with a lower sensitivity, 31.5%. The combined ANCA testing system (anti-PR3/cANCA + anti-MPO/pANCA) increased the sensitivity to 85.5% with a specificity of 98.6%. Conclusion. These results suggest that while anti-MPO is relatively specific for the diagnosis of systemic vasculitis, the combination system of immunoassays for anti-MPO and IIF for pANCA is highly specific and both tests should be used together given the high diagnostic precision required for these conditions. Because patients with ANCA associated vasculitis have either anti-MPO with pANCA or anti-PR3 with cANCA, and rarely both, a combined ANCA testing system including anti-PR3/cANCA and anti-MPO/pANCA is recommended to optimize the diagnostic performance of ANCA testing. (J Rheumatol 2001;28:1584-90)

A sensitive and specific assay for glutathione with potential application to glutathione disulphide, using high-performance liquid chromatography-tandem mass spectrometry

We have utilised the combination of sensitivity and specificity afforded by coupling high-performance liquid chromatography (HPLC) to a tandem mass spectrometer (MS-MS) to produce an assay which is suitable for assaying glutathione (GSH) concentrations in liver tissue. The sensitivity suggests it may also be suitable for extrahepatic tissues, The method has been validated for GSH using mouse liver samples and also allows the assay of GSSG. The stability of GSH under conditions relevant to the assay has been determined. A 20-mul amount of a diluted methanol extract of tissue is injected with detection limits of 0.2 pmol for GSH and 2 pmol for GSSG. The HPLC uses an Altima C-18 (150X4.6 mm, 5 mum) column at 35 degreesC. Chromatography utilises a linear gradient from 0 to 10% methanol in 0.1% formic acid over 5 min, with a final isocratic stage holding at 10% methanol for 5 min. Total flow rate is 0.8 ml/min. The transition from the M+H ion (308.1 m/z for GSH, and 613.3 m/z for GSSG) to the 162.0 m/z (GSH) and 355.3 m/z (GSSG) fragments are monitored. (C) 2001 Elsevier Science B.V. All rights reserved.