Dynamical simulations of charged soliton transport in conjugated polymers with the inclusion of electron-electron interactions

We present numerical studies of the transport dynamics of a charged soliton in conjugated polymers under the influence of an external time-dependent electric field. All relevant electron-phonon and electron-electron interactions are nearly fully taken into account by simulating the monomer displacements with classical molecular dynamics (MD) and evolving the wavefunction for the $\pi$ electrons by virtue of the adaptive time-dependent density matrix renormalization group (TDDMRG) simultaneously and nonadiabatically. It is found that after a smooth turn-on of the external electric field the charged soliton is accelerated at first up to a stationary constant velocity as one entity consisting of both the charge and the lattice deformation. An ohmic region (6 mV/$\text{\AA}$ $\leq E_0\leq$ 12 mV/$\text{\AA}$) where the stationary velocity increases linearly with the electric field strength is observed. The relationship between electron-electron interactions and charged soliton transport is also investigated in detail. We find that the dependence of the stationary velocity of a charged soliton on the on-site Coulomb interactions $U$ and the nearest-neighbor interactions $V$ is due to the extent of delocalization of the charged soliton defect.Comment: 25 pages, 15 figure

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

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

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

Partial undersampling of imbalanced data for cyber threats detection

Real-time detection of cyber threats is a challenging task in cyber security. With the advancement of technology and ease of access to the internet, more and more individuals and organizations are becoming the target for various cyber attacks such as malware, ransomware, spyware. The target of these attacks is to steal money or valuable information from the victims. Signature-based detection methods fail to keep up with the constantly evolving new threats. Machine learning based detection has drawn more attention of researchers due to its capability of detecting new and modified attacks based on previous attack's behaviour. The number of malicious activities in a certain domain is significantly low compared to the number of normal activities. Therefore, cyber threats detection data sets are imbalanced. In this paper, we proposed a partial undersampling method to deal with imbalanced data for detecting cyber threats. © 2020 ACM.E

What Turns Knowledge into Innovative Products? The Role of Entrepreneurship and Knowledge Spillovers

The knowledge spillover theory of entrepreneurship seeks to explain the fundamentals and consequences of entrepreneurship with respect to economic performance. This paper uses the knowledge spillover theory to explain different innovation outcomes. We hypothesize that a high rate of entrepreneurship facilitates the process of turning knowledge into new-to-the-market innovation but has no effect on the relationship between knowledge and new-to-the-firm innovation. Our results using European country-level and pooled OLS, fixed- and random-effects regressions show that a high rate of entrepreneurship increases the chances that knowledge will become new-to-the-market innovation. The findings highlight the importance of Schumpeterian entrepreneurship in the process of the commercialization of knowledge. We discuss the implications for entrepreneurship and innovation policy

The impact of Labour Relations on Innovative Output: An Exploration of Firm-level Data in the Netherlands

A growing literature on determinants of innovative per- formance focuses on factors such as market structure, firm size, (regional and international) knowledge spill- overs, R&D collaboration, conditions for appropriation of innovation benefits, and others. This paper contrib- utes to an aspect that is still sparsely explored: The im- pact of labour relations and Human Resource Manage- ment (HRM) practices on a firm’s innovative behaviour. Our empirical findings identify that active HRM policies, including job rotation, performance pay, and high qualification levels of personnel contribute positively to innovative performance

Knowledge, Entrepreneurship and Performance: Evidence from country-level and firm-level studies

This book investigates the interrelations between knowledge and entrepreneurship, and their consequences with regard to economic performance. Both knowledge and entrepreneurship are recognized as new twin driving forces for economic growth. Recent studies suggest that neither knowledge nor entrepreneurship alone is sufficient to drive growth. Investing in new knowledge is only a necessary condition; new knowledge needs to be exploited and put into commercial use such that it can lead to higher levels of competitiveness and economic growth. Entrepreneurship is acknowledged to play an important role in this process. It is thus essential for economists and policy-makers to understand how knowledge and entrepreneurship relate to each other and why they lead to economic growth. The five empirical chapters included in this book provide new insights into aforementioned issues on the firm- and country-level. Chapter 2 is based on a country-level analysis and identifies the moderating role of entrepreneurship in turning knowledge into innovation, which may ultimately lead to economic growth. Chapters 3 through 5, taking a firm-level perspective, investigate how small and medium-sized enterprises (SMEs) manage their knowledge assets (including organization knowledge and human resources) to stimulate innovation performance. Chapter 6 pays special attention to the determinants of SME growth. The findings of the chapters indicate that entrepreneurship catalyzes the transformation of new knowledge into innovation on the one hand; and the other hand, knowledge plays a significant role in stimulating innovation performance and SME growth

The Feasibility of Imaging Myocardial Ischemic/Reperfusion Injury Using \u3csup\u3e99m\u3c/sup\u3eTc-labeled Duramycin in a Porcine Model

When pathologically externalized, phosphatidylethanolamine (PE) is a potential surrogate marker for detecting tissue injuries. 99mTc-labeled duramycin is a peptide-based imaging agent that binds PE with high affinity and specificity. The goal of the current study was to investigate the clearance kinetics of 99mTc-labeled duramycin in a large animal model (normal pigs) and to assess its uptake in the heart using a pig model of myocardial ischemia–reperfusion injury. Methods The clearance and distribution of intravenously injected 99mTc-duramycin were characterized in sham-operated animals (n = 5). In a closed chest model of myocardial ischemia, coronary occlusion was induced by balloon angioplasty (n = 9). 99mTc-duramycin (10–15 mCi) was injected intravenously at 1 hour after reperfusion. SPECT/CT was acquired at 1 and 3 hours after injection. Cardiac tissues were analyzed for changes associated with acute cellular injuries. Autoradiography and gamma counting were used to determine radioactivity uptake. For the remaining animals, 99mTc-tetrafosamin scan was performed on the second day to identify the infarct site. Results Intravenously injected 99mTc-duramycin cleared from circulation predominantly via the renal/urinary tract with an α-phase half-life of 3.6 ± 0.3 minutes and β-phase half-life of 179.9 ± 64.7 minutes. In control animals, the ratios between normal heart and lung were 1.76 ± 0.21, 1.66 ± 0.22, 1.50 ± 0.20 and 1.75 ± 0.31 at 0.5, 1, 2 and 3 hours post-injection, respectively. The ratios between normal heart and liver were 0.88 ± 0.13, 0.80 ± 0.13, 0.82 ± 0.19 and 0.88 ± 0.14. In vivo visualization of focal radioactivity uptake in the ischemic heart was attainable as early as 30 min post-injection. The in vivo ischemic-to-normal uptake ratios were 3.57 ± 0.74 and 3.69 ± 0.91 at 1 and 3 hours post-injection, respectively. Ischemic-to-lung ratios were 4.89 ± 0.85 and 4.93 ± 0.57; and ischemic-to-liver ratios were 2.05 ± 0.30 to 3.23 ± 0.78. The size of 99mTc-duramycin positive myocardium was qualitatively larger than the infarct size delineated by the perfusion defect in 99mTc-tetrafosmin uptake. This was consistent with findings from tissue analysis and autoradiography. Conclusion 99mTc-duramycin was demonstrated, in a large animal model, to have suitable clearance and biodistribution profiles for imaging. The agent has an avid target uptake and a fast background clearance. It is appropriate for imaging myocardial injury induced by ischemia/reperfusion