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91.
Researchers on organisational ambidexterity have proposed several solutions to address the potential conflicts between exploration activities and exploitation activities. Unlike simultaneous ambidexterity, sequential ambidexterity – defined as temporal switching between exploration and exploitation – has not been examined fully, and the conditions under which this temporal switching can be successful are unclear. This paper proposes the concept of temporal switching capability to better understand the process by which sequential ambidexterity is executed. In addition, we hypothesise that performance effects are contingent upon firm-specific factors: a firm’s business strategy and absorptive capacity. Utilising three sources of data – a secondary database, annual reports and a survey administered to 145 firms in the electronics industry with 10-year observations – we find support for our hypotheses. The results show that the temporal switching capability positively relates to new product performance and that business strategy type and absorptive capacity have moderating effects. The results are meaningful in both theory and practice. 相似文献
92.
Almost all variables in biology are nonstationarily stochastic. For these variables, the conventional tools leave us a feeling that some valuable information is thrown away and that a complex phenomenon is presented imprecisely. Here, we apply recent advances initially made in the study of ocean waves to study the blood pressure waves in the lung. We note first that, in a long wave train, the handling of the local mean is of predominant importance. It is shown that a signal can be described by a sum of a series of intrinsic mode functions, each of which has zero local mean at all times. The process of deriving this series is called the "empirical mode decomposition method." Conventionally, Fourier analysis represents the data by sine and cosine functions, but no instantaneous frequency can be defined. In the new way, the data are represented by intrinsic mode functions, to which Hilbert transform can be used. Titchmarsh [Titchmarsh, E. C. (1948) Introduction to the Theory of Fourier Integrals (Oxford Univ. Press, Oxford)] has shown that a signal and i times its Hilbert transform together define a complex variable. From that complex variable, the instantaneous frequency, instantaneous amplitude, Hilbert spectrum, and marginal Hilbert spectrum have been defined. In addition, the Gumbel extreme-value statistics are applied. We present all of these features of the blood pressure records here for the reader to see how they look. In the future, we have to learn how these features change with disease or interventions. 相似文献
93.
SV Singh PJ Benson X Hu A Pal H Xia SK Srivastava S Awasthi HA Zaren JL Orchard YC Awasthi 《Canadian Metallurgical Quarterly》1998,128(2):197-204
A commercial patient dose verification system utilizing non-invasive metal oxide semiconductor field effect transistor (MOSFET) dosimeters originally designed for radiotherapy applications has been evaluated for use at diagnostic energy levels. The system features multiple dosimeters that may be used to monitor entrance or exit skin dose and intracavity doses in phantoms in real time. We have characterized both the standard MOSFET dosimeter designed for radiotherapy dose verification and a newly developed "high sensitivity" MOSFET dosimeter designed for lower dose measurements. The sensitivity, linearity, angular response, post-exposure response, and physical characteristics were evaluated. The average sensitivity (free in air, including backscatter) of the radiotherapy MOSFET dosimeters ranged from 3.55 x 10(4) mV per C kg(-1) (9.2 mV R(-1)) to 4.87 x 10(4) mV per C kg(-1) (12.6 mV R(-1)) depending on the energy of the x-ray field. The sensitivity of the "high sensitivity" MOSFET dosimeters ranged from 1.15 x 10(5) mV per C kg(-1) (29.7 mV R(-1)) to 1.38 x 10(5) mV per C kg(-1) (35.7 mV R(-1)) depending on the energy of the x-ray field. The high sensitivity dosimeters demonstrated excellent linearity at high energies (90 and 120 kVp) and acceptable linearity at lower energies (60 kVp). The angular response was significant for free-in-air exposures, as illustrated by the sensitivity differences between the two sides of the dosimeter, but was excellent for measurements within a tissue equivalent cylinder. The post-exposure drift response is a complicated but reproducible function of time. Real-time monitoring requires little if any corrections for the post-exposure drift response. The MOSFET dosimeter system brings some unique capabilities to diagnostic radiology dosimetry including small size, real-time capabilities, nondestructive measurement, good linearity, and a predictable angular response. 相似文献
94.
Fine-needle aspiration is now accepted as the initial procedure for diagnosing a thyroid nodule. General pathologists inevitably will be asked to interpret aspirates as this diagnostic tool continues to be more widely used. This procedure is relatively inexpensive, is safe, and nearly always provides information useful in deciding how to manage the patient. We emphasize the importance of obtaining a representative sample of good quality. This often occurs when the "interventional pathologist" performs the aspirations, but there is no reason that another practitioner cannot become expert. Both histologic and cytologic features are reviewed from normal thyroid tissue, autoimmune thyroiditis, adenomatoid nodules, and follicular neoplasms. We encourage the use of clear, simple, and uniform terminology to facilitate communication. 相似文献
95.
An amplitude-sensitive optical heterodyne polarimeter was set up to monitor noninvasively the aqueous glucose concentration in a rabbit's eye. A Zeeman laser in conjunction with a Glan-Thompson analyzer was used to generate an optical heterodyne signal. The amplitude of the heterodyne signal linearly related to the optical rotation angle of the aqueous glucose. The concentration of the aqueous glucose in a rabbit's eyeball was measured in vivo. There was a 30-min time delay between observations of aqueous glucose and blood glucose. The detection capability and the reproducibility of the experiment are demonstrated and discussed. 相似文献
96.
Current multimedia extensions provide a mechanism for general-purpose processors to meet the growing performance demand of multimedia applications. However, the computing performance of these extensions is often limited for the design conceptions of the single data stream. This paper presents an architecture called “multi-streaming SIMD” that enables current multimedia extensions to simultaneously manipulate multiple data streams. To efficiently and flexibly realize the proposed architecture, an operation cell is designed by fusing the logic gates and the storage cells together. Multiple operation cells then are connected to compose a register file with the ability of performing SIMD operations called “Multimedia Operation Storage Unit (MOSU)”. Further, many MOSUs are used to compose a multi-streaming SIMD computing engine that can simultaneously manipulate multiple data streams and exploit the subword parallelisms of the elements in each data stream. This paper also designs three instruction modes (global, coupling, and isolated modes) for programmers to dynamically configure the multi-streaming SIMD computing engine at the instruction level to manipulate different amounts of data streams. Simulation results show that when the multi-streaming SIMD architecture has four 4-register MOSUs, it provides a factor of 3.3×–5.5× performance enhancement for traditional MMX extensions on 12 multimedia kernels. 相似文献
97.
98.
Ya‐Hui Yang Sidney S. Yang Kan‐Sen Chou 《Journal of the Society for Information Display》2010,18(10):745-748
Abstract— This study investigates the effects of subjecting zinc oxide (ZnO) thin films to laser irradiation. The optical, structural, and electrical properties of the as‐deposited and laser‐irradiated films at different laser energies were studied. The transmittances without/with laser irradiation showed a net increase from 85 to 92% (@550 nm) for 250‐nm ZnO films, indicating an improvement in sample crystal linity. In addition, laser treatment decreased the ZnO band gap. Composition structure analysis shows that the crystallinity increased when the laser energy increased. Thin‐film transistors (TFTs) with a ZnO active layer were fabricated. The mobility of as‐deposited ZnO TFT devices (0.19 cm2/V‐sec) increased more than 2.5 times for ZnO of unirradiated laser treatment (0.49 cm2/V‐sec). 相似文献
99.
The automated structural optimization system (ASOS) proposed in the previous work incorporates the image-preprocessing techniques, the image-interpreting technique, and the automated shape-optimization modeling techniques to successfully obtain an autonomously integrated topology and shape optimization. However, the characteristic value-based image-interpreting technique used in ASOS is unable to accurately interpret complicated hole shapes, necessitating the use of the hole shape-adjusting strategy in addition to the hole-expanding strategy and the interference analysis in the automated shape-optimization modeling techniques to obtain a viable initial design and side constraints of design variables. In order to solve the above-mentioned problem in ASOS, this paper proposes the improved automated structural optimization system (IASOS) and uses the polygonal image-interpreting technique to replace the characteristic value-based image-interpreting technique used in ASOS. This alteration significantly increases the accuracy of image interpretation. Moreover, it can simplify the process of automated shape-optimization modeling techniques, reduce the design duration, and produce better results. 相似文献
100.
The field of micro–electro–mechanical systems and microfabrication has produced micro-total-analysis systems, which are widely
used in medicine, diagnostics, and biological and chemical research. For the development of high precision drug delivery systems,
micropumps with a lead zirconate titanate (PZT) actuator, which has a fast response time and high resolution, are most likely
to be applied in implementations. To improve the performance of PZT micropumps utilized in the microfluidics field, suitable
models are required to enable the optimization of the PZT actuator driving circuits. This study proposes a modified Butterworth–Van
Dyke (BVD) model which consists of a BVD model in series with an electrical resistance that describes a PZT actuator driven
by a square pulse with a relatively high voltage and low frequency for micropump applications. Experiments were conducted
to assess parameters of the model at various voltages; they indicate that the electrical resistance is essential for modeling
the PZT actuator of the micropump. The electrical model was verified using a SPICE simulation, whose numerical results were
compared with the experimental data for the current response of the PZT actuator. The results show a close correlation between
the simulation of the electrical model and the measurements of the PZT actuator under real operating conditions. 相似文献