828 resultados para expected value of information


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This paper seeks to advance the theory and practice of the dynamics of complex networks in relation to direct and indirect citations. It applies social network analysis (SNA) and the ordered weighted averaging operator (OWA) to study a patent citations network. So far the SNA studies investigating long chains of patents citations have rarely been undertaken and the importance of a node in a network has been associated mostly with its number of direct ties. In this research OWA is used to analyse complex networks, assess the role of indirect ties, and provide guidance to reduce complexity for decision makers and analysts. An empirical example of a set of European patents published in 2000 in the renewable energy industry is provided to show the usefulness of the proposed approach for the preference ranking of patent citations.

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Unlike other works of art (painting, sculpture, etc.) a musical composition should be performed, it should sound to become accessible. Therefore, the role of the musical masterly performance is extremely important. But presently it has increased in importance when music through mass communication media i.e. radio, television, sound recording becomes in the full sense of the word the property of millions. Art in all its genres as a means of information helps to recreate a picture of one or other epoch as a whole. Moreover, art has a profound impact on education: it can be positive or negative, creative or destructive. Let us dwell on such aspect of music as means of information and the value of musical mastery activity for brining information to hearers of the alternating generations. Unlike other works of art (painting, sculpture etc.) a musical composition should be performed, it should sound to become intelligible. Therefore, the role of the musical masterly performance is extremely important. But presently it becomes particularly great in the XXI century when music becomes a true property of the masses due to mass media – radio, television, sound recording.

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Fuzzy data envelopment analysis (DEA) models emerge as another class of DEA models to account for imprecise inputs and outputs for decision making units (DMUs). Although several approaches for solving fuzzy DEA models have been developed, there are some drawbacks, ranging from the inability to provide satisfactory discrimination power to simplistic numerical examples that handles only triangular fuzzy numbers or symmetrical fuzzy numbers. To address these drawbacks, this paper proposes using the concept of expected value in generalized DEA (GDEA) model. This allows the unification of three models - fuzzy expected CCR, fuzzy expected BCC, and fuzzy expected FDH models - and the ability of these models to handle both symmetrical and asymmetrical fuzzy numbers. We also explored the role of fuzzy GDEA model as a ranking method and compared it to existing super-efficiency evaluation models. Our proposed model is always feasible, while infeasibility problems remain in certain cases under existing super-efficiency models. In order to illustrate the performance of the proposed method, it is first tested using two established numerical examples and compared with the results obtained from alternative methods. A third example on energy dependency among 23 European Union (EU) member countries is further used to validate and describe the efficacy of our approach under asymmetric fuzzy numbers.

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2000 Mathematics Subject Classification: 62P20, 91B42

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Using the case of a low cost airline company’s website we analyze some special research questions of information technology valuation. The distinctive characteristics of this research are the ex post valuation perspective; the parallel and comparative use of accounting and business valuation approaches; and the integrated application of discounted cash flow and real option valuation. As the examined international company is a strategic user of e-technology and wants to manage and account intangible IT-assets explicitly, these specific valuation perspectives are gaining practical significance.

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Successful introduction of information technology applications in various operations of hotel management is vital to most service firms. In recent decades, technologies of information, automation, and communication are increasingly recognized as essential components of a hotel company’s strategic plan. In this study, 62 super-deluxe hotels (5 star), deluxe hotels (4 star), and tourist hotels (3 star) in Korea are examined for differences in the impact of information technology services on guest’ satisfaction, guest convenience, and operational efficiency. The findings generally suggest that the impacts of information technology-enhanced services vary according to the category of hotels in Korea. The results of the study are expected to assist managers in the selections and implementation of information technology systems in their hotel.

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The technologies that empower biometrics have been around for a number of years, but until recently these technologies have been viewed as exotic. In the not too distant future biometrics will be used to regulate internal processes and to improve services in the hospitality and tourism industries. This paper provides an understanding of the current use of biometrics in general and its practical value for the future in hospitality and tourism. The study presents a review of current practices of biometrics with special reference to the hospitality and tourism businesses, addresses key issues imposed by this technology, and identifies business and marketing implications for these industries.

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The main research objective of this study was to find out whether perceived value significantly affects consumers’ purchase intention. Additionally, this study examined if there are any significant differences in perceived value for different fast-food restaurant brands and attempted to identify which fast-food restaurant is perceived to be the industry leader. A total number of six fast-food restaurants (McDonalds, Subway, Starbucks, Wendy’s, Burger King, and Taco Bell) were selected. Findings showed that among the five perceived service value dimensions, Starbucks is the leader in terms of quality, emotional response, and reputation. Multivariate analysis of variance (MANOVA) and multiple regression analysis were performed to test the study hypotheses. Results indicated that there were significant differences in perceived value for different fast-food restaurant brands. Besides, monetary and behavioral price significantly affects consumers’ purchase intention. Findings are expected to help hospitality marketers to strategically manage their brands.

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The wide-spread impact of exotic fishes especially Oreochromis niloticus and Lates niloticus together with over fishing in the Victoria and Kyoga lake basins during the 1950s and 1960s, caused endemic species such as the previously most important Oreochromis esculentus to become virtually extinct in the two lakes by the 1970s. Based on reports of presence of this native species in some satellite lakes within the two lake basins, a set of satellite lakes in the Victoria basin (Nabugabo lakes: Kayanja and Kayugi), were sampled between 1997-2002 with an objective of assessing their value as conservation sites for O. esculentus. Other satellite lakes (Mburo and Kachera) also in the Victoria basin, and Lemwa, Kawi and Nabisojjo, in the Kyoga basin, were sampled for comparison. Among the Nabugabo lakes, O. esculentus was more abundant in Lake Kayanja (20.1 %) ofthe total fish catch by weight compared to Lake Kayugi (1.4 %). The largest fish examined (38.7 cm TL) was caught in Lake Kayugi, (also the largest in all satellite lakes sampled), while the smallest (6.6 cm TL) was from Lake Kayanja. Fish from Lake Kayugi had a higher condition factor K (1.89± 0.02) than that from Lake Kayanja (1.53±0.0I), which was the second highest (compared with other satellite lakes) to Lake Kawi (1.92±0.2). Diatoms, especially Aulacoseira, which were previously known to be the best food for O. esculentus in Lake Victoria were mostly encountered (93.2 %) in fish stomachs from Lake Kayugi. In Lake Kayanja the dominant food item was the blue green algae (Planktolyngbya) while Microcystis was the most abundant diet item in fish from other satellite lakes. There were more male than female fish (ratio 1:0.91 and 1: 0.79 in lakes Kayugi and Kayanja respectively). This is comparable to the situation in Lake Victoria before the species got depleted. The highest mean fecundity was (771±218 eggs) recorded in Lake Kayugi compared to Lake Kayanja (399±143). Based on the results from Lake Kayugi, where diatoms dominated the diet of O. esculentus and where the largest, most fecund and healthy fish were found, this lake would be a most valuable site for the conservation of O. esculentus and the best source of fish, for restocking and for captive-propagation. This lake is therefore recommended for protection from over exploitation and misuse.

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"4-63."

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IS/IT investments are seen has having an enormous potential impact on the competitive position of the firm, on its performance, and demand an active and motivated participation of several stakeholder groups. The shortfall of evidence concerning the productivity of IT became known as the ‘productivity paradox’. As Robert Solow, the Nobel laureate economist stated “we see computers everywhere except in the productivity statistics”. An important stream of research conducted all over the world has tried to understand these phenomena, called in the literature as «IS business value» field. However, there is a gap in the literature, addressing the Portuguese situation. No empirical work has been done to date in order to understand the impact of Information Technology adoption on the productivity of those firms. Using data from two surveys conducted by the Portuguese National Institute of Statistics (INE), Inquiry to the use of IT by Portuguese companies (IUTIC) and the Inquiry Harmonized to (Portuguese) companies (accounting data), this study relates (using regression analysis) the amounts spent on IT with the financial performance indicator Returns on Equity, as a proxy of firm productivity, of Portuguese companies with more than 250 employees. The aim of this paper is to shed light on the Portuguese situation concerning the impact of IS/IT on the productivity of Portuguese top companies. Empirically, we test the impact of IT expenditure on firm productivity of a sample of Portuguese large companies. Our results, based on firm-level data on Information Technology expenditure and firm productivity as measured by return on equity (1186 observations) for the years of 2003 and 2004, exhibit a negative impact of IT expenditure on firm productivity, in line with “productivity paradox” claimants.

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To compare time and risk to biochemical recurrence (BR) after radical prostatectomy of two chronologically different groups of patients using the standard and the modified Gleason system (MGS). Cohort 1 comprised biopsies of 197 patients graded according to the standard Gleason system (SGS) in the period 1997/2004, and cohort 2, 176 biopsies graded according to the modified system in the period 2005/2011. Time to BR was analyzed with the Kaplan-Meier product-limit analysis and prediction of shorter time to recurrence using univariate and multivariate Cox proportional hazards model. Patients in cohort 2 reflected time-related changes: striking increase in clinical stage T1c, systematic use of extended biopsies, and lower percentage of total length of cancer in millimeter in all cores. The MGS used in cohort 2 showed fewer biopsies with Gleason score ≤ 6 and more biopsies of the intermediate Gleason score 7. Time to BR using the Kaplan-Meier curves showed statistical significance using the MGS in cohort 2, but not the SGS in cohort 1. Only the MGS predicted shorter time to BR on univariate analysis and on multivariate analysis was an independent predictor. The results favor that the 2005 International Society of Urological Pathology modified system is a refinement of the Gleason grading and valuable for contemporary clinical practice.

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This study aimed at evaluating whether human papillomavirus (HPV) groups and E6/E7 mRNA of HPV 16, 18, 31, 33, and 45 are prognostic of cervical intraepithelial neoplasia (CIN) 2 outcome in women with a cervical smear showing a low-grade squamous intraepithelial lesion (LSIL). This cohort study included women with biopsy-confirmed CIN 2 who were followed up for 12 months, with cervical smear and colposcopy performed every three months. Women with a negative or low-risk HPV status showed 100% CIN 2 regression. The CIN 2 regression rates at the 12-month follow-up were 69.4% for women with alpha-9 HPV versus 91.7% for other HPV species or HPV-negative status (P < 0.05). For women with HPV 16, the CIN 2 regression rate at the 12-month follow-up was 61.4% versus 89.5% for other HPV types or HPV-negative status (P < 0.05). The CIN 2 regression rate was 68.3% for women who tested positive for HPV E6/E7 mRNA versus 82.0% for the negative results, but this difference was not statistically significant. The expectant management for women with biopsy-confirmed CIN 2 and previous cytological tests showing LSIL exhibited a very high rate of spontaneous regression. HPV 16 is associated with a higher CIN 2 progression rate than other HPV infections. HPV E6/E7 mRNA is not a prognostic marker of the CIN 2 clinical outcome, although this analysis cannot be considered conclusive. Given the small sample size, this study could be considered a pilot for future larger studies on the role of predictive markers of CIN 2 evolution.

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Phase I trials use a small number of patients to define a maximum tolerated dose (MTD) and the safety of new agents. We compared data from phase I and registration trials to determine whether early trials predicted later safety and final dose. We searched the U.S. Food and Drug Administration (FDA) website for drugs approved in nonpediatric cancers (January 1990-October 2012). The recommended phase II dose (R2PD) and toxicities from phase I were compared with doses and safety in later trials. In 62 of 85 (73%) matched trials, the dose from the later trial was within 20% of the RP2D. In a multivariable analysis, phase I trials of targeted agents were less predictive of the final approved dose (OR, 0.2 for adopting ± 20% of the RP2D for targeted vs. other classes; P = 0.025). Of the 530 clinically relevant toxicities in later trials, 70% (n = 374) were described in phase I. A significant relationship (P = 0.0032) between increasing the number of patients in phase I (up to 60) and the ability to describe future clinically relevant toxicities was observed. Among 28,505 patients in later trials, the death rate that was related to drug was 1.41%. In conclusion, dosing based on phase I trials was associated with a low toxicity-related death rate in later trials. The ability to predict relevant toxicities correlates with the number of patients on the initial phase I trial. The final dose approved was within 20% of the RP2D in 73% of assessed trials.

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The objectives of the study were to evaluate the performance of sentinel lymph node biopsy (SLNB) in detecting occult metastases in papillary thyroid carcinoma (PTC) and to correlate their presence to tumor and patient characteristics. Twenty-three clinically node-negative PTC patients (21 females, mean age 48.4 years) were prospectively enrolled. Patients were submitted to sentinel lymph node (SLN) lymphoscintigraphy prior to total thyroidectomy. Ultrasound-guided peritumoral injections of (99m)Tc-phytate (7.4 MBq) were performed. Cervical single-photon emission computed tomography and computed tomography (SPECT/CT) images were acquired 15 min after radiotracer injection and 2 h prior to surgery. Intra-operatively, SLNs were located with a gamma probe and removed along with non-SLNs located in the same neck compartment. Papillary thyroid carcinoma, SLNs and non-SLNs were submitted to histopathology analysis. Sentinel lymph nodes were located in levels: II in 34.7 % of patients; III in 26 %; IV in 30.4 %; V in 4.3 %; VI in 82.6 % and VII in 4.3 %. Metastases in the SLN were noted in seven patients (30.4 %), in non-SLN in three patients (13.1 %), and in the lateral compartments in 20 % of patients. There were significant associations between lymph node (LN) metastases and the presence of angio-lymphatic invasion (p = 0.04), extra-thyroid extension (p = 0.03) and tumor size (p = 0.003). No correlations were noted among LN metastases and patient age, gender, stimulated thyroglobulin levels, positive surgical margins, aggressive histology and multifocal lesions. Sentinel lymph node biopsy can detect occult metastases in PTC. The risk of a metastatic SLN was associated with extra-thyroid extension, larger tumors and angio-lymphatic invasion. This may help guide future neck dissection, patient surveillance and radioiodine therapy doses.