OALib Journal期刊

ISSN: 2333-9721



匹配条件: “Pirjol Florentina” ,找到相关结果约232条。
Pirjol Florentina,Maxim Raluca
Annals of the University of Oradea : Economic Science , 2012,
Abstract: The main theme of this paper is the role of organizational culture in a company and its way of expression within the organization, for its management, for its employees and for its competition. Organizational culture is undoubtedly one of the fashionable areas of management, with a relatively recent history. Its purpose is to sensitize readers to the importance of organizational culture for the success of an enterprise, and its objectives were: to define organizational culture and its influence factors, as well as to explain the role of its components in the organization as a whole and for its members. Practically, the interest in organizational culture began in the 7th decade, largely due to the performances of Japanese companies, performance explained by their specific culture. Although the concept is increasingly met in international and local literature, the process that prevents its practical implementation is the lack of scientific (theoretical) research at a company ′s level. The old generation of leaders lead based on knowledge acquired years ago, few are those who really consistently do research and are up to speed with the latest news in management, or in the economic field in general. This paper aims to identify key conditions that determine human activity in an organization and their relationship to the successful implementation of an organizational culture by examplifing great successes of international companies. This is relevant, not only because these companies have huge incomes and recorded notable successes, but also because they enter and develop on the local market, trying to implement their thinking. Thus, local businesses can improve their business by adopting and adapting this way of thinking. The rezults of the research results reflect the fact that despite the concept that people are the main value of an organization, companies continue to ignore their employees, instead seeking the magic formula, the immediate solution or the latest management tool, not giving organizational culture the importance it deserves. We want to preclude the notion that it is easier to implement a new policy than to invest time to analyze and improve internal organizational culture. An organizational culture of success tries to improve old ways without losing the tradition, it brings advantages to the organization, to the management and to the employees.
Pirjol Florentina,Maxim Raluca Georgiana,Nagy Andrea
Annals of the University of Oradea : Economic Science , 2011,
Abstract: Tourism is an industry of the future, having the potential to provide significant revenues, and an industry of 'beauty', because it will protect, preserve and contribute to arranging the environment affected by other human activities. This is why it is very important to know the evolution of this underdeveloped field in our country. This paper is intended as a study on current trends in Romanian tourism without any claim of being an exhaustive research on the industry, describing the main indices of tourist traffic and their influence on Romanian tourism. Nowadays, we witness three main trends in Romanian tourism: sustainability, ecotourism and the increasing presence of cultural tourism. Ecotourism, as a form of tourism, has emerged from people's need to withdraw in nature, to visit and learn about the natural areas which have or have not a national or international protection status. Cultural tourism appears as a type of tourism clearly differentiated from other forms or types of tourism, particularly through motivation. It can be defined as a form of tourist mobility whose primary goal is broadening the horizon of knowledge by uncovering its architectural and artistic heritage and the areas in which it originates. Sustainability for tourism, as for other industries, has three independent aspects: economic, socio-cultural and environmental. Sustainability implies permanence, which means that sustainable tourism requires the optimal use of resources, minimizing the negative economic, socio-cultural and ecological impact, maximizing the benefits upon local communities, national economies and conservation of nature. Regarding statistical data, in what quantity is concerned, there is an increase in Romanian tourism, but in what quality is concerned there is a setback for tourism in the last years. This aspect should make public authorities take concern in improving the infrastructure and the quality of the touristical activity and in diversifying entertainment.
Heavy Quark Distribution Functions from QCD
D. Pirjol
Physics , 1994,
Abstract: The structure function of a heavy quark in a heavy hadron in electroproduction is calculated from QCD. Its deviation from the parton model prediction (a delta function) is shown to be governed by a shape function, similar to the one recently proposed by Neubert and Bigi {\em et al.} to describe the end-point behaviour of the lepton spectrum in semileptonic $B\to X_ue\bar\nu$ decays and the line shape in $B\to X_s\gamma$. Two new sum rules are derived which extend the Bjorken-Dunietz-Taron sum rule by including corrections suppressed by the inverse heavy quark mass.
Bound on $\cosα$ from exclusive weak radiative B decays
Dan Pirjol
Physics , 2000, DOI: 10.1016/S0370-2693(00)00834-0
Abstract: We present a bound on the weak phase $\alpha$ from isospin-breaking effects in weak radiative decays, which requires the CP-averaged branching ratios for the weak radiative decays $B^\pm\to \rho^\pm \gamma$, $B^0\to \rho^0/\omega \gamma$, $B\to K^* \gamma$ and the photon energy spectrum in $B\to\gamma \ell\nu_\ell$. We carefully identify all sources of isospin breaking, which could possibly mask information about the CKM parameters. They are introduced by diagrams with photon bremsstrahlung off the spectator quark and diagrams with annihilation penguin topologies. The former can be eliminated by combining $B\to\rho\gamma$ and $B\to K^{*}\gamma$ data, whereas the latter effects are OZI-suppressed and can be controlled by measuring also the modes $B_s\to \rho(\omega)\gamma$. The resulting bound excludes values of $\alpha$ around $90^\circ$, provided that the combined ratio ${\cal B}(B^\pm \to \rho^\pm\gamma)/{\cal B}(B^0 \to \rho^0/\omega\gamma) \times {\cal B}(B^0 \to K^{*0}\gamma)/{\cal B}(B^\pm \to K^{*\pm}\gamma)$ is found to be different from 1.
Long-run growth rate in a random multiplicative model
Dan Pirjol
Physics , 2015, DOI: 10.1063/1.4886699
Abstract: We consider the long-run growth rate of the average value of a random multiplicative process $x_{i+1} = a_i x_i$ where the multipliers $a_i=1+\rho\exp(\sigma W_i - \frac12 \sigma^2 t_i)$ have Markovian dependence given by the exponential of a standard Brownian motion $W_i$. The average value $\langle x_n\rangle$ is given by the grand partition function of a one-dimensional lattice gas with two-body linear attractive interactions placed in a uniform field. We study the Lyapunov exponent $\lambda(\rho,\beta) = \lim_{n\to \infty} \frac{1}{n} \log \langle x_n\rangle$ at fixed $\beta = \frac12 \sigma^2 t_n n$, and show that it is given by the equation of state of the lattice gas in thermodynamical equilibrium. The Lyapunov exponent has discontinuous first derivatives along a curve in the $(\rho,\beta)$ plane ending at a critical point $(\rho_C,\beta_C)$, which is related to a phase transition in the equivalent lattice gas. Using the equivalence of the lattice gas with a bosonic system, we obtain the exact solution for the equation of state in the thermodynamical limit $n\to \infty$.
Rare radiative B decays in perturbative QCD
Dan Pirjol
Physics , 2001,
Abstract: We report on recent progress on perturbative QCD calculations of certain exclusive rare weak $B$ meson decays involving hard photons. In the limit of a photon energy $E_\gamma$ much larger than $\Lambda_{QCD}$, the amplitudes for such processes can be analyzed in a twist expansion in powers of $\Lambda/E_\gamma$. The leading twist amplitude is given by the convolution of a hard scattering amplitude with the $B$ meson light-cone wavefunction. This approach is applied to a calculation of the leptonic radiative $B\to \gamma \ell \nu_\ell$ formfactors and to an estimate of the weak annihilation contribution to the penguin decays $B\to \rho(\omega)\gamma$. As an application we discuss a few methods for constraining the unitarity triangle with exclusive radiative B decays.
Bounding the penguin effects on determinations of $α$ from $B^0(t)\toπ^+π^-$ decays
Dan Pirjol
Physics , 1999, DOI: 10.1103/PhysRevD.60.054020
Abstract: In the absence of the QCD penguin contributions a measurement of the time-dependent asymmetry in the decay $B^0(t)\to \pi^+\pi^-$ gives directly the weak angle $\alpha$. Several bounds have been proposed in the literature on the magnitude of the penguin effects on this determination, the prototype of which is the isospin bound of Grossman and Quinn. It is pointed out that large strong final state interactions could cause these bounds to overestimate the real penguin effect. A new flavor SU(3) bound is proposed, requiring only the charge-averaged branching ratios for $B^0\to \pi^+\pi^-$ and $B_s\to K^+K^-$, which exactly takes into account all relevant amplitudes and electroweak penguin effects. This bound on the penguin-induced error on the determination of the weak phase $\alpha$ holds even without a knowledge of the direct CP asymmetry in the $\pi^+\pi^-$ channel.
Rescattering and electroweak penguin effects in determinations of the weak phase $γ$
Dan Pirjol
Physics , 1999, DOI: 10.1016/S0168-9002(00)00010-3
Abstract: Determinations of the CKM phase $\gamma$ from weak nonleptonic $B$ decays are affected by electroweak (EW) penguins and rescattering effects. In this talk it is explained how the EW penguin effects can be controlled with the help of SU(3) symmetry, by relating them to tree-level amplitudes. The impact of the final-state interactions on the determination of $\gamma$ from $B^+\to K\pi$ decays is studied numerically, showing that they can be important. A few alternative methods are discussed which use additional decays to eliminate their effects.
Phase transition in a log-normal Markov functional model
Dan Pirjol
Quantitative Finance , 2010, DOI: 10.1063/1.3526679
Abstract: We derive the exact solution of a one-dimensional Markov functional model with log-normally distributed interest rates in discrete time. The model is shown to have two distinct limiting states, corresponding to small and asymptotically large volatilities, respectively. These volatility regimes are separated by a phase transition at some critical value of the volatility. We investigate the conditions under which this phase transition occurs, and show that it is related to the position of the zeros of an appropriately defined generating function in the complex plane, in analogy with the Lee-Yang theory of the phase transitions in condensed matter physics.
Explosive behavior in a log-normal interest rate model
Dan Pirjol
Quantitative Finance , 2011,
Abstract: We consider an interest rate model with log-normally distributed rates in the terminal measure in discrete time. Such models are used in financial practice as parametric versions of the Markov functional model, or as approximations to the log-normal Libor market model. We show that the model has two distinct regimes, at high and low volatilities, with different qualitative behavior. The two regimes are separated by a sharp transition, which is similar to a phase transition in condensed matter physics. We study the behavior of the model in the large volatility phase, and discuss the implications of the phase transition for the pricing of interest rate derivatives. In the large volatility phase, certain expectation values and convexity adjustments have an explosive behavior. For sufficiently low volatilities the caplet smile is log-normal to a very good approximation, while in the large volatility phase the model develops a non-trivial caplet skew. The phenomenon discussed here imposes thus an upper limit on the volatilities for which the model behaves as intended.

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