1,087 research outputs found

    Short-timescale Fluctuations in the Difference Light Curves of QSO 0957+561A,B: Microlensing or Noise?

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    From optical R band data of the double quasar QSO 0957+561A,B, we made two new difference light curves (about 330 days of overlap between the time-shifted light curve for the A image and the magnitude-shifted light curve for the B image). We observed noisy behaviours around the zero line and no short-timescale events (with a duration of months), where the term event refers to a prominent feature that may be due to microlensing or another source of variability. Only one event lasting two weeks and rising - 33 mmag was found. Measured constraints on the possible microlensing variability can be used to obtain information on the granularity of the dark matter in the main lensing galaxy and the size of the source. In addition, one can also test the ability of the observational noise to cause the rms averages and the local features of the difference signals. We focused on this last issue. The combined photometries were related to a process consisting of an intrinsic signal plus a Gaussian observational noise. The intrinsic signal has been assumed to be either a smooth function (polynomial) or a smooth function plus a stationary noise process or a correlated stationary process. Using these three pictures without microlensing, we derived some models totally consistent with the observations. We finally discussed the sensitivity of our telescope (at Teide Observatory) to several classes of microlensing variability.Comment: MNRAS, in press (LaTeX, 14 pages, 22 eps figures

    Empirical study of the business growth strategy related to the added value by intellectual capital

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    [EN] Four consecutive years of more than a thousand Spanish companies from different economic sectors are analyzed to determine the influence of intellectual capital on the business growth strategy. One of the purposes of this work is to establish a classification criterion of the strategic behaviour of a company linked to the growth of three factors: the demand of the sector, the sales of the company and the financial sustainability of the company. Another purpose is to develop and validate an appropriate classification of where the value added by human intellectual capital is structurally concentrated and used according to the strategic behaviour, growth and sector of the company. Interesting conclusions are drawn about the strategic behaviour of the company and its intangible capital, as well as a different method for classifying companies according to their growth, which helps predict business profitability.The authors would like to acknowledge the grants T-CUE Doctoral prize for research on topics directly related to business needs, the grants of the PhD extraordinary award and the support of the University of Burgos to facilitate access to data gathering in relation to the work presented in the paper.Alcalde-Delgado, R.; Sáiz-Bárcena, L.; Olmo, R.; Pérez, C. (2020). Empirical study of the business growth strategy related to the added value by intellectual capital. International Journal of Production Management and Engineering. 8(1):1-12. https://doi.org/10.4995/ijpme.2020.10817OJS11281Alcalde, R, Manzanedo M A, Sáiz-Bárcena L (2016). Empirical evidence for a classification of firm performance according to a sustainable growth rate model. Book of Proceedings International Joint Conference - CIO-ICIEOM-IIE-AIM (IJC 2016).Álvarez, H.F. (2008). La estructura de financiamiento y el crecimiento de las pequeñas y medianas empresas. doi: 10.13140/2.1.2627.8084Amouzesh, N., Moeinfar, Z. and Mousavi, Z. (2011). Sustainable Growth Rate and Firm Performance: Evidence From Iran Stock Exchange. International Journal of Business and Social Science, 2 (23), 249-255.Ashford, N. (2016). De-[Constructing] Growth. Sustainability, 8(11), 1140. https://doi.org/10.3390/su8111140Chen, M.-C., Cheng, S.-J., Hwang, Y. (2005). An empirical investigation of the relationship between intellectual capital and firms' market value and financial performance. Journal of Intellectual Capital, 6 (2),159-176. https://doi.org/10.1108/14691930510592771Davidsson, P., Achtenhagen, L. and Naldi, L. (2010). Small firm growth. Foundations and Trends in Entrepreneur-ship, 6 (2), 69-166. https://doi.org/10.1561/0300000029Demir, R., Wennberg, K., & McKelvie, A. (2017). The strategic management of high-growth firms: A review and theoretical conceptualization. Long Range Planning, 50(4), 431-456. https://doi.org/10.1016/j.lrp.2016.09.004Firer, S.; Mitchell Williams, S. (2003). Intellectual capital and traditional measures of corporate performance. Journal of intellectual capital, 4 (3), 348-360. https://doi.org/10.1108/14691930310487806Gan, K. and Saleh, Z. (2008). Intellectual capital and corporate performance of technology-intensive companies: Malaysia evidence. Asian Journal of Business and Accounting, 1 (1), 113-130.García Muñiz, L.H. (2011). Evidencia empírica de la evaluación del modelo de crecimiento sostenible de Higgins en empresas mexicanas durante el periodo 1998-2008. (Doctoral thesis). Instituto Politécnico Nacional, México D.F.Ghanei, H. Ramezani Kheibari, A. (2015) A Survey of the relationship between intellectual capital and firm performance criteria. Journal of Scientific Research and Development, 2 (7), 280-284.Godet, M. (1994). From Anticipation to Action: a handbook of strategic prospective. Paris, Francia: Unesco.Greco, G., Ferramosca, S., Allegrini, M. (2014). Exploring intellectual capital in family firms. An empirical investi-gation. International Journal of Learning and Intellectual Capital, 11 (2), pp. 91-106. https://doi.org/10.1504/IJLIC.2014.060802Guerras, L.M. and Navas, E. (2015). La Dirección estratégica de la empresa. Teoría y Aplicaciones. Navarra, España: Aranzadi.Gupta, M. (2015). Intellectual Capital & Firm Profitability: An Empirical Study on the IT Sector listed in NSE. Global Journal of Multidisciplinary studies, 4 (4), pp. 105-108.Hajeb, H.R., Moghaddam, A.G. and Alipour, S. (2015). An investigation of intellectual capital impact on companies' market value and financial performace. Academic Journal of Accounting and Economic Researches, 4 (3), 131-139.Haris, M., Yao, H., Tariq, G., Malik, A., & Javaid, H. M. (2019). Intellectual Capital Performance and Profitability of Banks: Evidence from Pakistan. Journal of Risk and Financial Management, 12(2), 56. https://doi.org/10.3390/jrfm12020056Higgins, R.C. (1977). How much growth can a firm afford?. Financial Management, 6 (3), 7-16. https://doi.org/10.2307/3665251Higgins, R.C. (2007). Analysis of Financial Management. New York: McGraw-Hill.Joshi, M., Cahill, D., Sidhu, J., Kansal, M. (2013) Intellectual capital and financial perfor-mance: an evaluation of the Australian financial sector. Journal of intellectual capital, 14 (2), 264-285. https://doi.org/10.1108/14691931311323887Kabue, L. W., & Kilika, J. M. (2016). Firm resources, core competencies and sustainable competitive advantage: An integrative theoretical framework. Journal of management and strategy, 7(1), 98-108. https://doi.org/10.5430/jms.v7n1p98Kai Wah Chu, S., Hang Chan, K., Wu, W.W. (2011). Charting intellectual capital performance of the gateway to China. Journal of Intellectual Capital, 12 (2), 249-276. https://doi.org/10.1108/14691931111123412Kaplan, R.S. and Norton, D.P. (2004). Strategy maps: Converting intangible assets into tangible outcomes. Boston: Harvard Business School Press.Lambert, S. (2015). The importance of classification to business model research. Journal of Business Models, 3(1),49-61.Maditinos, D., Chatzoudes, D., Tsairidis, C.; Theriou, G. (2011). The impact of intellectual capital on firms' market value and financial performance. Journal of Intellectual Capital, 12 (1), 132-151. https://doi.org/10.1108/14691931111097944Magreta, J. (2001). La Administración en la Nueva Economía. Nuevas Perspectivas. Mexico: Oxford University Press.Mahdjour, S. (2015). Set up for growth? - an exploratory analysis of the relationship of growth intention and business models. Manchester: The International Society for Professional Innovation Management (ISPIM). https://doi.org/10.1142/S1363919615400095Mukherjee, T., & Sen, S. S. (2019). Intellectual Capital and Corporate Sustainable Growth: The Indian Evidence. The East Asian Journal of Business Management (EAJBM), 9(2), 5-15. https://doi.org/10.13106/jbees.2019.vol9.no2.5Najafizadeh, S.A., Fordoei, E.J. (2014). Investigation the Effect of Intellectual Capital on Market Value and Financial Performance of Listed Companies in Tehran Stock Exchange. Global Journal of Management Studies and Re-searches, 1 (3), 143-150.Peñate Santana, Y. (2013). Factores determinantes del crecimiento de las pymes: el papel de las capacidades diná-micas y la orientación emprendedora. (Doctoral thesis). University of Oviedo, Spain.Pew Tan, H., Plowman, D. and Hancock, P. (2007). Intellectual capital and financial returns of companies. Journal of Intellectual Capital, 8 (1), 76-95. https://doi.org/10.1108/14691930710715079Pulic, A. (1998). Measuring the performance of intellectual potential in knowledge economy. Paper presented at the 2nd McMaster Word Congress on Measuring and Managing Intellectual Capital, McMaster University, Hamilton.Pulic, A. (2000). VAIC™-an accounting tool for IC management. International journal of technology management, 20 (5-8), 702-714.https://doi.org/10.1504/IJTM.2000.002891Pulic, A. (2004). Intellectual capital-does it create or destroy value?. Measuring business excellence, 8 (1), 62-68. https://doi.org/10.1108/13683040410524757Pulic, A. (2008). The principles of intellectual capital efficiency-A brief description. Inspired by Knowledge in Or-ganisations, 182 (1), 67-93.Salazar, B. C., Villegas, E. (2019). Intellectual capital of industrial sector Mexican companies measured through the VAIC™ model. Journal of Administrative Science, 1(1), 1-9.Sallenave, J.-P. (1991). Gerencia y planeación estratégica. Bogotá, Colombia: Norma.Sallenave, J.P. (2002). Gerencia integral. Bogotá, Colombia: Norma.Sardo, F., & Serrasqueiro, Z. (2018). Intellectual capital, growth opportunities, and financial performance in European firms: Dynamic panel data analysis. Journal of Intellectual Capital, 19(4), 747-767. https://doi.org/10.1108/JIC-07-2017-0099Schwab, L., Gold, S., & Reiner, G. (2019). Exploring financial sustainability of SMEs during periods of production growth: A simulation study. International Journal of Production Economics, 212, 8-18. https://doi.org/10.1016/j.ijpe.2018.12.023Shiu, H. (2006), The application of the value added intellectual coefficient to measure corporate performance: evidence from technological firms, International Journal of Management, 23(2), 356-365.Socolich Mansilla, M.I. (2007). Desempeño financiero y creación de valor en empresas chilenas fusionadas. (Doctoral thesis). Universidad de Chile, Chile.Smriti, N., & Das, N. (2018). The impact of intellectual capital on firm performance: a study of Indian firms listed in COSPI. Journal of Intellectual Capital, 19(5), 935-964. https://doi.org/10.1108/JIC-11-2017-0156Svanadze, S., Kowalewska, M. (2015). The measurement of intellectual capital by VAIC method example of WIG20. Online Journal of Applied Knowledge Management, 3 (2), 36-44.Ulum, I., Ghozali, I. and Purwanto, A. (2014). Intellectual Capital Performance of Indonesian Banking Sector: A Modi-fied VAIC (M-VAIC) Perspective. Asian Journal of Finance & Accounting, 6 (2), 103-123. https://doi.org/10.5296/ajfa.v6i2.5246Xu, J., & Wang, B. (2018). Intellectual capital, financial performance and companies' sustainable growth: Evidence from the Korean manufacturing industry. Sustainability, 10(12), 4651. https://doi.org/10.3390/su10124651Zia, M., Muhammad, H., Arbab, S., Shahzad, A., Bilal, S. (2014). VAIC and Firm Performance: Banking Sector Of Pakistan. Information and Knowledge Management, 4 (2), 100-107

    Energetic performance of landfill and digester biogas in a domestic cooker

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    The energetic performance of landfill biogas (LB) and biodigester biogas (BB) from municipal waste was examined in consumption tests. These tests were performed in situ at a gas generation plant associated with a landfill facility in Madrid (Spain) and following the standard UNE-EN 30-2-1 (1999). The jets of a domestic cooker commonly used for natural gas (NG) or liquefied petroleum gas (LPG) were modified to operate with the biogases produced at the facility. The working pressures best suited to the tested gases, i.e., to avoid flashback and flame lift, and to ensure the stability and correct functioning of the flame during combustion, were determined by trial and error. Both biogases returned optimum energetic performance for the transfer of heat to water in a metallic recipient (as required by the above standard) at a supply pressure of 10 mbar. Domestic cookers are normally supplied with NG at a pressure of 20 mbar, at which pressure the energetic performance of G20 reference gas was higher than that of both biogases (52.84% compared to 38.06% and 49.77% respectively). Data concerning these issues involving also unexplored feedstock are required for the correct conversions of domestic cookers in order to avoid risks of serious personal injuries or property damages

    Virtual Processes and Superradiance in Spin-Boson Models

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    We consider spin-boson models composed by a single bosonic mode and an ensemble of NN identical two-level atoms. The situation where the coupling between the bosonic mode and the atoms generates real and virtual processes is studied, where the whole system is in thermal equilibrium with a reservoir at temperature β1\beta^{-1}. Phase transitions from ordinary fluorescence to superradiant phase in three different models is investigated. First a model where the coupling between the bosonic mode and the jthj-th atom is via the pseudo-spin operator σ(j),z\sigma^{,z}_{(j)} is studied. Second, we investigate the generalized Dicke model, introducing different coupling constants between the single mode bosonic field and the environment, g1g_{1} and g2g_{2} for rotating and counter-rotating terms, respectively. Finally it is considered a modified version of the generalized Dicke model with intensity-dependent coupling in the rotating terms. In the first model the zero mode contributes to render the canonical entropy a negative quantity for low temperatures. The last two models presents phase transitions, even when only Hamiltonian terms which generates virtual processes are considered

    A Large Brightness Enhancement of the QSO 0957+561 A Component

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    We report an increase of more than 0.2 mag in the optical brightness of the leading image (A) of the gravitational lens Q0957+561, detected during the 09/2000 -- 06/2001 monitoring campaign (2001 observing season). The brightening is similar to or even greater than the largest change ever detected during the 20 years of monitoring of this system. We discuss two different provisional explanations to this event: intrinsic source variability or microlensing (either short timescale microlensing or cessation of the historical microlensing). An exhaustive photometric monitoring of Q0957+561 is needed until summer of 2002 and during 2003 to discriminate between these possibilities.Comment: 13 pages including 3 figures and 1 table. Accepted for publication in ApJ Let

    QSO 2237+0305 VR light curves from Gravitational Lenses International Time Project optical monitoring

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    We present VR observations of QSO 2237+0305 conducted by the GLITP collaboration from 1999 October 1 to 2000 February 3. The observations were made with the 2.56 m Nordic Optical Telescope at Roque de los Muchachos Observatory, La Palma (Spain). The PSF fitting method and an adapted version of the ISIS subtraction method have been used to derive the VR light curves of the four components (A-D) of the quasar. The mean errors range in the intervals 0.01-0.04 mag (PSF fitting) and 0.01-0.02 mag (ISIS subtraction), with the faintest component (D) having the largest uncertainties. We address the relatively good agreement between the A-D light curves derived using different filters, photometric techniques, and telescopes. The new VR light curves of component A extend the time coverage of a high magnification microlensing peak, which was discovered by the OGLE team.Comment: 15 pages, 3 figures, ApJ accepted (Feb 19
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