932 resultados para Chain of value
Resumo:
We introduce a novel way of measuring the entropy of a set of values undergoing changes. Such a measure becomes useful when analyzing the temporal development of an algorithm designed to numerically update a collection of values such as artificial neural network weights undergoing adjustments during learning. We measure the entropy as a function of the phase-space of the values, i.e. their magnitude and velocity of change, using a method based on the abstract measure of entropy introduced by the philosopher Rudolf Carnap. By constructing a time-dynamic two-dimensional Voronoi diagram using Voronoi cell generators with coordinates of value- and value-velocity (change of magnitude), the entropy becomes a function of the cell areas. We term this measure teleonomic entropy since it can be used to describe changes in any end-directed (teleonomic) system. The usefulness of the method is illustrated when comparing the different approaches of two search algorithms, a learning artificial neural network and a population of discovering agents. (C) 2004 Elsevier Inc. All rights reserved.
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In this paper we propose a range of dynamic data envelopment analysis (DEA) models which allow information on costs of adjustment to be incorporated into the DEA framework. We first specify a basic dynamic DEA model predicated on a number or simplifying assumptions. We then outline a number of extensions to this model to accommodate asymmetric adjustment costs, non-static output quantities, non-static input prices, and non-static costs of adjustment, technological change, quasi-fixed inputs and investment budget constraints. The new dynamic DEA models provide valuable extra information relative to the standard static DEA models-they identify an optimal path of adjustment for the input quantities, and provide a measure of the potential cost savings that result from recognising the costs of adjusting input quantities towards the optimal point. The new models are illustrated using data relating to a chain of 35 retail department stores in Chile. The empirical results illustrate the wealth of information that can be derived from these models, and clearly show that static models overstate potential cost savings when adjustment costs are non-zero.
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3-Fluoromethyl-7-(N-substituted aminosulfonyl)-1,2,3,4-tetrahydroisoquinolines (14, 16, and 18-22) are highly potent and selective inhibitors of phenylethanolamine N-methyltransferase (PNMT). Molecular modeling studies with 3-fluoromethyl-7-(N-alkyl aminosulfonyl)-1,2,3,4-tetrahydroisoquinolines, such as 16, suggested that the sulfonamide -NH-could form a hydrogen bond with the side chain of Lys57. However, SAR studies and analysis of the crystal structure of human PNMT (hPNMT) in complex with 7 indicated that the sulfonamide oxygens, and not the sulfonamide -NH-, formed favorable interactions with the enzyme. Thus, we hypothesized that replacement of the sulfonamide -NH-with a methylene group could result in compounds that would retain potency at PNMT and that would have increased lipophilicity, thus increasing the likelihood they will cross the blood brain barrier. A series of 3-fluoromethyl-7-sulfonyl-1,2,3,4-tetrahydroisoquinolines (23-30) were synthesized and evaluated for their PNMT inhibitory potency and affinity for the R2-adrenoceptor. A comparison of these compounds with their isosteric sulfonamides (14, 16, and 18-22) showed that the sulfones were more lipophilic but less potent than their corresponding sulfonamides. Sulfone 24 (hPNMT K-i = 1.3 mu M) is the most potent compound in this series and is quite selective for PNMT versus the R2-adrenoceptor, but 24 is less potent than the corresponding sulfonamide, 16 (hPNMT K-i = 0.13 mu M). We also report the crystal structure of hPNMT in complex with sulfonamide 15, from which a potential hydrogen bond acceptor within the hPNMT active site has been identified, the main chain carbonyl oxygen of Asn39. The interaction of this residue with the sulfonamide -NH-is likely responsible for much of the enhanced inhibitory potency of the sulfonamides versus the sulfones.
Resumo:
The wild mungbean, Vigna radiata ssp. sublobata, is an 'old world' tropical species indigenous throughout the better watered areas of northern Australia. Variation among 115 accessions, mainly from Australia, West Timor, and Papua New Guinea, was evaluated for several diverse traits. The plants were cultivated in the field at 2 sowing dates, at both a tropical and a subtropical location, with 6 accessions from India and a mungbean cultivar for comparison. Substantial variation was identified for traits of potential agronomic, adaptive, or taxonomic interest. For some traits, like phenology, the variation appeared to be systematic, with plausible underlying physiological and/or adaptive explanation. Among accessions, wild type traits, like prostrate habit, more gracile morphology, twining form, and small hard seeds, tended to be associated. There was a general geographic trend for lines collected from locations more remote from where mungbean has historically been cultivated to show greater expression of wild type traits, with few 'traits of domestication' evident in the Australian accessions. Some of the identified variation, e. g. higher seed protein content, hardseededness, and putative disease resistance, may be of value in mungbean variety improvement. A more targetted evaluation of the collection would likely reveal other adaptations, especially tolerance to environmental stresses. As such, the wild accessions are a potentially valuable if under-utilised germplasm resource.
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A culster analysis was performed on 78 cases of Alzheimer's disease (AD) to identify possible pathological subtypes of the disease. Data on 47 neuropathological variables, inculding features of the gross brain and the density and distribution of senile plaques (SP) and neurofibrillary tangles (NFT) were used to describe each case. Cluster analysis is a multivariate statistical method which combines together in groups, AD cases with the most similar neuropathological characteristics. The majority of cases (83%) were clustered into five such groups. The analysis suggested that an initial division of the 78 cases could be made into two major groups: (1) a large group (68%) in which the distribution of SP and NFT was restricted to a relatively small number of brain regions, and (2) a smaller group (15%) in which the lesions were more widely disseminated throughout the neocortex. Each of these groups could be subdivided on the degree of capillary amyloid angiopathy (CAA) present. In addition, those cases with a restricted development of SP/NFT and CAA could be divided further into an early and a late onset form. Familial AD cases did not cluster as a separate group but were either distributed between four of the five groups or were cases with unique combinations of pathological features not closely related to any of the groups. It was concluded that multivariate statistical methods may be of value in the classification of AD into subtypes. © 1994 Springer-Verlag.
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The thesis will examine the role and impact of the concept of the community within the structural reorganisation of English local government between 1992 and 1995. The methodological approach adopted within this thesis has been to compare the use, application and significance of the community with a case study of a specific local authority and its preparations for reorganisation. The authority in question was Wychavon District Council located in the County of Hereford and Worcester. The conclusions from this case study were then compared to the role and significance of the community in the reviews of other local authorities in England. This study produced two important results. These were that there was an established body of literature which argued that the community could be of value to local government and that the community should be identified by measuring individuals sense of belonging and feelings of attachment, as well as such daily activities as shopping and working (which help to stimulate these feelings). The then Conservative Government even instructed the specially appointed Commission to apply this particular interpretation of the community to their reviews, and to attempt to base any new unitary authorities upon the social and spatial area it created. The Conservative Government also gave the Commission a Community Index to assist with the identification of communities, and appointed the pollsters MORI to support the Commission with the task of identifying the emotional and more subjective senses of community. The Commission eventually came to rely entirely on the MORI polls, and whilst these polls attempted to faithfully apply the Governments interpretation of the community, they unfortunately produced small and often complex communities, which the Commission felt could not be applied to its reviews. This therefore led to the community becoming a secondary consideration to the factors of cost and efficiency. Furthermore the problematic nature of the community - that is, the production of small and complex communities - was repeated in this thesis' own survey of community identities in the District of Wychavon. In fact this authority's proposals for reorganisation were based almost entirely upon the factors of cost, size and efficiency.
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This is a theoretical paper that examines the interplay between individual and collective capabilities and competencies and value transactions in collaborative environments. The theory behind value creation is examined and two types of value are identified, internal value (Shareholder value) and external value (Value proposition). The literature on collaborative enterprises/network is also examined with particular emphasis on supply chains, extended/virtual enterprises and clusters as representatives of different forms and maturities of collaboration. The interplay of value transactions and competencies and capabilities are examined and discussed in detail. Finally, a model is presented which consists of value transactions and a table which compares the characteristics of different types of collaborative enterprises/networks. It is proposed that this model presents a platform for further research to develop an in-depth understanding into how value may be created and managed in collaborative enterprises/networks.
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Business networks have been described as cooperative arrangements between independent business organisations that vary from contractual joint ventures to informal exchanges of information. This collaboration has become recognised as an innovative and efficient tool for organising interdependent activities, with benefits accruing to both firms and the local economy. For a number of years, resources have been devoted to supporting Irish networking policies. One recent example of such support is the Irish government's target of €20 million per annum for five years to support the creation of enterprise-led networks. It is imperative that a clear rationale for such interventions is established, as the opportunity cost of public funds is high. This article, therefore, develops an evaluation framework for such networking interventions. This framework will facilitate effective programme planning, implementation and evaluation. It will potentially show how a chain of cause-and-effect at both micro and macro-levels for networking interventions can be established.
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The majority of research on the pharmaceutical sector has focused on an overall micro economic, medical oriented welfare issues, whereas the marketing management role of the innovative drug manufacturer has to a large extent been disregarded. Using the case of Turkey, through a series of in-depth interviews with highly innovative companies, other marketing management possibilities to develop pricing strategies and plan for profit are explored based on broader definitions of value and transparency. Our results suggest that pharmaceutical companies as well as governments might have a too narrow focus of value and underestimate the potential long term benefits of a broader approach to marketing management and long term relationships between the various stakeholders.
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Purpose – The growth of women in management has been argued to offer a route to reduce organizational and social inequality. The purpose of this paper is to explore the careers and experiences of female managers from a variety of organizations operating in the West Midlands region of the UK. Design/methodology/approach – This study is based on 56 interviews conducted with women managers within various sectors. The interviewees also completed pictorial careers maps, which along with interview recordings were analyzed. Findings – The key themes to emerge from this research centre upon the factors that draw women into management (which we term seductive elements) as well as some of the hindering practices that prevent women from progressing. Significantly, we find that managerial careers are associated with gendered assumptions and practices (e.g. facilitating and developing people) which contribute to construct management (done by women) as bounded-up characteristically with “feminized” behaviours. Research limitations/implications – The research is based upon a relatively small sample that is multi-sectorial. Wider studies that increase population size, together with deeper studies that hold sectorial variables constant would further add weight to the findings presented here. Practical implications – The paper draws attention to the “lived reality” of doing management, which, we argue often, for women in particular involves the reconciliation of contradictions and conflicting pressures. We draw attention to the lack of “alternative models” of organization and highlight the potential for gender-focus mentoring and management education. Originality/value – The paper is of value in giving voice to a selection of women managers by allowing them to reflect upon and explore their experience of management. The paper also documents the day-to-day reality of women's managerial careers that require the re-enactment and reproduction of stereotypical gender norms.
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Attitudes towards the environment can be manifest in two broad categories, namely anthropocentric and ecocentric. The former regards nature as of value only insofar as it is useful to humanity, whereas the latter assigns intrinsic value to natural entities. Industrial society can be characterised as being dominated by anthropocentrism, which leads to the assumption that a majority of people hold anthropocentric values. However, research shows the most widely held values are ecocentric, which implies that many people's actions are at variance with their values. Furthermore, policy relating to environmental issues is predominantly anthropocentric, which implies it is failing to take account of the values of the majority. Research among experts involved in policy formulation has shown that their values, often ecocentric, are excluded from the policy process. The genetic modification of food can be categorised as anthropocentric, which implies that the technique is in conflict with widely held ecocentric values. This thesis examines data collected from interviews with individuals who have an influence on the debate surrounding the introduction of genetically modified foods, and can be considered 'experts'. Each interviewee is categorised according to whether their values and actions are ecocentric or anthropocentric, and the linkages between the two and the arguments used to justify their positions are explored. Particular emphasis is placed on interviewees who have ecocentric values but act professionally in an anthropocentric way. Finally, common themes are drawn out, and the features the arguments used by the interviewees have in common are outlined.
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The purpose of this paper is to deal with the outcomes of a so-called “employability management needs analysis” that is meant to provide more insight into current employability management activities and its possible benefits for Information and Communication Technology (ICT) professionals working in Small- and Medium-sized enterprises (SMEs) throughout Europe. A considerable series of interviews (N=107) were conducted with managers in SMEs in seven European countries, including Germany, Greece, Italy, the Netherlands, Norway, Poland, and the UK. A semi-structured interview protocol was used during the interviews to cover three issues: employability (13 items), ageing (8 items), and future developments and requirements (13 items). Analysis of all final interview transcriptions was at a national level using an elaborate common coding scheme. Although an interest in employability emerged, actual policy and action lagged behind. The recession in the ICT sector at the time of the investigation and the developmental stage of the sector in each participating country appeared connected. Ageing was not seen as a major issue in the ICT sector because managers considered ICT to be a relatively young sector. There appeared to be a serious lack of investment in the development of expertise of ICT professionals. Generalization of the results to large organizations in the ICT sector should be made with caution. The interview protocol developed is of value for further research and complements survey research undertaken within the employability field of study. It can be concluded that proactive HRM (Human Resource Management) policies and strategies are essential, even in times of economic downturn. Employability management activities are especially important in the light of current career issues. The study advances knowledge regarding HRM practices adopted by SMEs in the ICT sector, especially as there is a gap in knowledge about career development issues in that particular sector.
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Product design decisions can have a significant impact on the financial and operation performance of manufacturing companies. Therefore good analysis of the financial impact of design decisions is required if the profitability of the business is to be maximised. The product design process can be viewed as a chain of decisions which links decisions about the concept to decisions about the detail. The idea of decision chains can be extended to include the design and operation of the 'downstream' business processes which manufacture and support the product. These chains of decisions are not independent but are interrelated in a complex manner. To deal with the interdependencies requires a modelling approach which represents all the chains of decisions, to a level of detail not normally considered in the analysis of product design. The operational, control and financial elements of a manufacturing business constitute a dynamic system. These elements interact with each other and with external elements (i.e. customers and suppliers). Analysing the chain of decisions for such an environment requires the application of simulation techniques, not just to any one area of interest, but to the whole business i.e. an enterprise simulation. To investigate the capability and viability of enterprise simulation an experimental 'Whole Business Simulation' system has been developed. This system combines specialist simulation elements and standard operational applications software packages, to create a model that incorporates all the key elements of a manufacturing business, including its customers and suppliers. By means of a series of experiments, the performance of this system was compared with a range of existing analysis tools (i.e. DFX, capacity calculation, shop floor simulator, and business planner driven by a shop floor simulator).
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This thesis reports on the development of a technique to evaluate hydraulic conductivities in a soil (Snowcal) subject to freezing conditions. The technique draws on three distinctly different disciplines, Nuclear Physics, Soil Physics and Remote Sensing to provide a non-destructive and reliable evaluation of hydraulic conductivity throughout a freezing test. Thermal neutron radiography is used to provide information on local water/ice contents at anytime throughout the test. The experimental test rig is designed so that the soil matrix can be radiated by a neutron beam, from a nuclear reactor, to obtain radiographs. The radiographs can then be interpreted, following a process of remote sensing image enhancement, to yield information on relative water/ice contents. Interpretation of the radiographs is accommodated using image analysis equipment capable of distinguishing between 256 shades of grey. Remote sensing image enhancing techniques are then employed to develop false colour images which show the movement of water and development of ice lenses in the soil. Instrumentation is incorporated in the soil in the form of psychrometer/thermocouples, to record water potential, electrical resistance probes to enable ice and water to be differentiated on the radiographs and thermocouples to record the temperature gradient. Water content determinations are made from the enhanced images and plotted against potential measurements to provide the moisture characteristic for the soil. With relevant mathematical theory pore water distributions are obtained and combined with water content data to give hydraulic conductivities. The values for hydraulic conductivity in the saturated soil and at the frozen fringe are compared with established values for silts and silty-sands. The values are in general agreement and, with refinement, this non-destructive technique could afford useful information on a whole range of soils. The technique is of value over other methods because ice lenses are actually seen forming in the soil, supporting the accepted theories of frost action. There are economic and experimental restraints to the work which are associated with the use of a nuclear facility, however, the technique is versatile and has been applied to the study of moisture transfer in porous building materials and could be further developed into other research areas.
Resumo:
The extent to which the surface parameters of Progressive Addition Lenses (PALs) affect successful patient tolerance was investigated. Several optico-physical evaluation techniques were employed, including a newly constructed surface reflection device which was shown to be of value for assessing semi-finished PAL blanks. Detailed physical analysis was undertaken using a computer-controlled focimeter and from these data, iso-cylindrical and mean spherical plots were produced for each PAL studied. Base curve power was shown to have little impact upon the distribution of PAL astigmatism. A power increase in reading addition primarily caused a lengthening and narrowing of the lens progression channel. Empirical measurements also indicated a marginal steepening of the progression power gradient with an increase in reading addition power. A sample of the PAL wearing population were studied using patient records and questionnaire analysis (90% were returned). This subjective analysis revealed the reading portion to be the most troublesome lens zone and showed that patients with high astigmatism (> 2.00D) adapt more readily to PALs than those with spherical or low cylindrical (2.00D) corrections. The psychophysical features of PALs were then investigated. Both grafting visual acuity (VA) and contrast sensitivity (CS) were shown to be reduced with an increase in eccentricity from the central umbilical line. Two sample populations (N= 20) of successful and unsuccessful PAL wearers were assessed for differences in their visual performance and their adaptation to optically induced distortion. The possibility of dispensing errors being the cause of poor patient tolerance amongst the unsuccessful wearer group was investigated and discounted. The contrast sensitivity of the successful group was significantly greater than that of the unsuccessful group. No differences in adaptation to or detection of curvature distortion were evinced between these presbyopic groups.