1,670 research outputs found

    Knowledge Management in the SME and its Relationship to Strategy, Family Orientation and Organization Learning

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    In this study, we examine the prevalence of different KM practices and the organizational determinants of KM among SMEs by conducting a quantitative study of empirical data from nearly 500 Dutch SMEs. Our empirical results show that knowledge is managed in a people-based approach in SMEs. SMEs are most likely to acquire knowledge by staying in touch with professionals and experts outside the company and they incline to share knowledge and experience by talking to each other. Furthermore, KM is dependent on other organizational resources and processes. Organizational learning and competitive strategy with a formality approach are the positive determinants of KM while family orientation is a negative determinant of it. One of the challenges in the current study was to clearly distinguish, on an empirical basis, the previously defined concepts of knowledge management practices and organizational learning. Although in theory, they are distinct, the results of this study lead us to conclude that they may overlap in practice. In the conclusion, we recommend a learning-oriented knowledge management model for SMEs which combines aspects of the two literatures

    Knowledge Management as a Strategic Tool to Foster Innovativeness of SMEs

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    This study examines the relationship between knowledge management (KM) (in terms of external acquisition and internal sharing) and innovation behavior. The concept of absorptive capacity and assumptions from the dynamic capabilities view underlie the proposed framework and hypotheses. The framework is empirically tested using a random sample of 649 Dutch small to medium sized enterprises (SMEs). Our empricial results indicate that external acquisition practices play a key role in fostering SMEs’ innovativeness while internal sharing practices do not appear to have a significant influence. External acquisition activity enhances a firm’s awareness of available knowledge opportunities. Firms which actively acquire external knowledge (regardless of the type of knowledge) may build a greater competitive dynamic capability to sense and seize business opportunities which in turn may lead to new or improved products or processes. We suggest that owners/entrepreneurs of SMEs and their firms will benefit in the long term if they strategically manage knowledge, especially using external acquisition practices

    Synthesis and super-resolution imaging performance of a refractive-index-controllable microsphere superlens

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    Microspheres can function as optical superlenses for nanoscale super-resolution imaging. The imaging performance is mainly affected by the size and refractive index of the microsphere. Precise control of these parameters is a challenging task but of fundamental importance to the further development of the technique. In this study, we demonstrate for the first time a nanoparticle-hybrid suspension polymerization approach to chemically synthesize high-quality microspheres (ZrO2/polystyrene) with optical properties that are highly controllable. Microspheres of different sizes (d: 2�20 μm) and refractive indexes (np: 1.590�1.685) were synthesized and their super-resolution imaging performances were evaluated and compared. Our results show that continuously increasing the refractive index of microspheres can enhance the imaging resolution and quality. A 60 nm resolution has been obtained in the wide-field imaging mode and a 50 nm resolution has been obtained in the confocal mode imaging of semiconductor chip samples. The obtained 50�60 nm resolutions have significantly gone beyond the conventional 200 nm resolution limit for visible light optical microscopes; the super-resolution mechanism has been discussed. The synthesized microsphere superlenses may find applications in many other areas as well, including nanolithography, nano-sensing, nano-diagnosis, nano-spectroscopy and ultra-high density optical data storage

    Finite-size effects on the chiral phase diagram of four-fermion models in four dimensions

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    We study the size dependence of the dynamical symmetry breaking in the four-dimensional Nambu-Jona-Lasinio model. We show that the presence of boundaries reduces the chiral breaking region, and this effect is strengthened for a larger number of compactified dimensions. A critical value for the length of the compactified dimensions exists, below which the dynamical symmetry breaking is not possible. Considering finite temperature and chemical potential, the chiral phase structure for the system with compactified dimensions is obtained. A gradual decreasing of the chiral breaking region with increasing of chemical potential is found. Also, at fixed chemical potential, the decreasing of the size of the system changes the order of the chiral phase transition.Comment: LATEX 14 pages 2 figure

    Tibetan sheep are better able to cope with low energy intake than Small-tailed Han sheep due to lower maintenance energy requirements and higher nutrient digestibilities

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    Tibetan sheep are indigenous to the Qinghai-Tibetan Plateau (QTP) and are well-adapted to and even thrive under the harsh alpine conditions. Small-tailed Han sheep were introduced to the plateau because of their high prolificacy and are maintained mainly in feedlots. Because of their different backgrounds, we hypothesised that Tibetan and Small-tailed Han sheep would differ in their utilization of energy intake and predicted that Tibetan sheep would cope better with low energy intake than Small-tailed Han sheep. To test this prediction, we determined nutrient digestibilities, energy requirements for maintenance and blood metabolite and hormone concentrations involved in energy metabolism in these breeds. Sheep of each breed (n = 24 of each, all wethers and 1.5 years of age) were distributed randomly into one of four groups and offered ad libitum diets of different digestible energy (DE) densities: 8.21, 9.33, 10.45 and 11.57 MJ DE/kg Dry matter (DM). Following 42 d of measuring feed intake, a 1-week digestion and metabolism experiment was done. DM intakes did not differ between breeds nor among treatments but, by design, DE intake increased linearly in both breeds as dietary energy level increased (P < 0.001). The average daily gain (ADG) was significantly greater in the Tibetan than Small-tailed Han sheep (P = 0.003) and increased linearly in both breeds (P < 0.001). In addition, from the regression analysis of ADG on DE intake, daily DE maintenance requirements were lower for Tibetan than for Small-tailed Han sheep (0.41 vs 0.50 MJ/BW0.75, P < 0.05). The DE and metabolizable energy (ME) digestibilities were higher in the Tibetan than Small-tailed Han sheep (P < 0.001) and increased linearly as the energy level increased in the diet (P < 0.001). At the lowest energy treatment, Tibetan sheep when compared with Small-tailed Han sheep, had: 1) higher serum glucose and glucagon, but lower insulin concentrations (P < 0.05), which indicated a higher capacity for gluconeogenesis and ability to regulate glucose metabolism; and 2) higher non-esterified fatty acids (NEFA) and lower very low density lipoprotein (VLDL) and triglyceride (TG) concentrations (P < 0.05), which indicated a higher capacity for NEFA oxidation but lower ability for triglyceride (TG) synthesis. We concluded that our prediction was supported as these differences between breeds conferred an advantage for Tibetan over Small-tailed Han sheep to cope better with low energy diets

    Adrenomedullin inhibits prostate cancer cell proliferation through a cAMP-independent autocrine mechanism

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    Adrenomedullin (AM) is a multifunctional peptide expressed in the normal and malignant prostate, and in prostate cancer cells. To elucidate the potential role of AM in prostate cancer, we have transfected the human AM gene into PC-3, DU 145, and LNCaP prostate cancer cells. Northern blot, Western blot, and radioimmunoassay techniques confirmed an increase in the synthesis and secretion of the 6kDa mature peptide, in the AM-transfected clones. Proliferation and cell cycle assays demonstrated that AM overexpression inhibited cell proliferation in PC-3 and LNCaP cells through a G0/G1 cell cycle arrest, but not in DU 145 cells. In vivo growth assays also confirmed that, at least in PC-3, AM produced a very significant reduction of tumor volume. In addition, the three cell lines expressed the CL/RCP/RAMP-2 receptor complex by RT-PCR, which suggests that AM peptide acts through an autocrine loop in prostate cancer cells. Although cAMP elevation is the most common pathway involved in AM signalling, stimulation of PC-3, DU 145, and LNCaP with synthetic AM did not increase intracellular cAMP. However, short-term stimulation of PC-3 cells with synthetic AM increased ERK1/2 activation. On the contrary, long-term stimulation, or AM overexpression, caused a reduction in the basal activation of ERK1/2. In summary, our results demonstrate that AM (either overexpressed or exogenously added) causes an inhibition of prostate cancer cell growth. This inhibition does not depend on changes in intracellular cAMP levels, but may be related to ERK1/2 activation

    Cavity implementation of quantum interference in a Λ\Lambda-type atom

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    A scheme for engineering quantum interference in a Λ\Lambda-type atom coupled to a frequency-tunable, single-mode cavity field with a pre-selected polarization at finite temperature is proposed. Interference-assisted population trapping, population inversions and probe gain at one sideband of the Autler-Townes spectrum are predicted for certain cavity resonant frequencies.Comment: 2 postscript figures are adde

    Mechanical Properties of GF/pCBT Composites and Their Fusion-Bonded Joints: Influence of Process Parameters

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    High melting viscosity of thermoplastic composites gives no way of using substantial volume fractions of reinforcing agents. This problem can be solved by in-situ polymerization of an extremely low-viscosity cyclic butylene terephthalate (CBT) resin. Continuous glass fiber-reinforced poly(cyclic butylene terephthalate) (GF/ðCBT) composites with high fiber fractions were manufactured, and the mechanical properties as a function of the catalyst mass fraction and fiber filling ratio were studied. The longitudinal tensile strength of the composites was enhanced by increasing the fiber volume fraction, and the influence of the fiber fraction on the bending strength of high fiber filling-ratio composites was evaluated. Furthermore, the mechanical properties and failure modes of GF/ðCBT fusion-bonded joints with different number of bonding areas of different lengths were investigated. It was found that high-strength composite materials can be obtained, which are applicable for fusion-bonded structures.Высокая вязкость плавления термопластических композиционных материалов не позволяет использовать значительные объемные долевые концентрации армирующих наполнителей. Эта проблема может быть решена путем in-situ полимеризации циклобутилентерефталатной смолы с чрезвычайно низкой вязкостью. Были изготовлены поли(циклобутилентерефталатные) композиционные материалы, армированные непрерывным стекловолокном (CF/pCBT) с высоким его содержанием, изучены механические свойства с учетом весовой доли катализатора и степени наполнения волокном. Предел прочности композиционных материалов при растяжении в продольном направлении возрос за счет увеличения объемной доли концентрации волокна, изучено влияние объемной доли волокна на прочность при изгибе для композиционных материалов с высокой степенью наполнения волокном. Кроме того, исследованы механические свойства и режимы разрушения GF/pCBT сваренных плавлением соединений с различным количеством зон связывания разной длины. Установлено, что можно получать высокопрочные композиционные материалы, пригодные для сваренных плавлением конструкций

    Incremental learning with social media data to predict near real-time events

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    International audienceIn this paper, we focus on the problem of predicting some particular user activities in social media. Our challenge is to consider real events such as message posting to friends or forwarding received ones, connecting to new friends, and provide near real-time prediction of new events. Our approach is based on latent factor models which can exploit simultaneously the timestamped interaction information among users and their posted content information. We propose a simple strategy to learn incrementally the latent factors at each time step. Our method takes only recent data to update latent factor models and thus can reduce computational cost. Experiments on a real dataset collected from Twitter show that our method can achieve performances that are comparable with other state-of-the-art non-incremental techniques

    Second-Order Belief Hidden Markov Models

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    Hidden Markov Models (HMMs) are learning methods for pattern recognition. The probabilistic HMMs have been one of the most used techniques based on the Bayesian model. First-order probabilistic HMMs were adapted to the theory of belief functions such that Bayesian probabilities were replaced with mass functions. In this paper, we present a second-order Hidden Markov Model using belief functions. Previous works in belief HMMs have been focused on the first-order HMMs. We extend them to the second-order model
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