877 resultados para Robô móvel não-holonômico
Resumo:
At present, the rate of small firm adoption of the Internet's ubiquitous World Wide Web (the web) far exceeds the actual exploitation its commercial potential. An inability to strategically acquire, comprehend and use external knowledge is proposed as a major barrier to optimal exploitation of the Internet. This paper discusses the limitations of applying market orientation theory to explain and guide small firm exploitation of the web. Absorptive capacity is introduced as an alternative theory that when viewed from an evolutionary perspective provides potentially more insightful discussion. An inability to detect emerging business model dominant designs is suggested to be a mixture of the nature of the technology that supports the Internet and underdeveloped small firm knowledge processing capabilities. We conclude with consideration of the practical and theoretical implications that arise from the paper.
Resumo:
Small firms are always vulnerable to complex technological change that may render their existing business model obsolete. This paper emphasises the need to understand how the Internet's ubiquitous World Wide Web is impacting on their operating environments. Consideration of evolutionary theory and the absorptive capacity construct provides the foundation for discussion of how learning and discovery take place within individuals, firms and the environments that interact with. Small firms, we argue, face difficulties identifying what routines and competencies are best aligned with the seemingly invisible dominant designs that support pursuit of new enterprise in web-impacted environments. We argue that such difficulties largely relate to an inability to acquire external knowledge and the subsequent reliance on existing internal selection processes that may reinforce the known, at the expense of the unknown. The paper concludes with consideration as to how managers can overcome the expected difficulties through the development of internal routines that support the continual search, evaluation and acquisition of specific external knowledge.
Resumo:
Fundamental to the development of new customer value offerings via web-based commerce is a small firm's ability to strategically acquire and exploit knowledge. The focus of this paper is the empirical testing of a normative web-based commerce adoption model developed from a review of the extant literature related to electronic marketing, the Internet and the diffusion of new innovations. A preliminary test of the model's theoretical contentions lent support to its overall focus, but found that the firm's existing learning capabilities were diminished during the adoption of web-based commerce. Consequently, sub-optimal adoption outcomes were associated with insufficient knowledge development.
Resumo:
Low level strategic supplements constitute one of the few options for northern beef producers to increase breeder productivity and profitability. Objectives of the project were to improve the cost-effectiveness of using such supplements and to improve supplement delivery systems. Urea-based supplements fed during the dry season can substantially reduce breeder liveweight loss and increase fertility during severe dry seasons. Also when fed during the late wet season these supplements increased breeder body liveweight and increased fertility of breeders in low body condition. Intake of dry lick supplements fed free choice is apparently determined primarily by the palatability of supplements relative to pasture, and training of cattle appears to be of limited importance. Siting of supplementation points has some effect on supplement intake, but little effect on grazing behaviour. Economic analysis of supplementation (urea, phosphorus or molasses) and weaning strategies was based on the relative efficacy of these strategies to maintain breeder body condition late in the dry season. Adequate body condition of breeders at this time of the year is needed to avoid mortality from under-nutrition and achieve satisfactory fertility of breeders during the following wet season. Supplements were highly cost-effective when they reduced mortality, but economic returns were generally low if the only benefit was increased fertility.
Resumo:
Tämä tutkielma keskittyy julkisen kaupunkitilan kontrollin eri muotoihin. Ihmiset käyttävät kaupunkitilaa eri tavoin ja eri tarkoituksiin. Tilan sallitut ja kielletyt käyttömuodot ovat aina erilaisten toiveiden yhteensovittamista: yhteisen neuvottelun tulos. Tilaa myös kontrolloidaan vastaamaan erilaisia toiveita ja odotuksia. Tutkielmassa julkisen tilan kontrollin muodot on jaettu kolmeen: tilan fyysinen muokkaaminen, tilan valvonta ja asenteisiin vaikuttaminen esimerkiksi politiikkaohjelmilla. Tärkeimpänä kiinnostuksen kohteena on tilanne, jossa jokin toiminta kielletään kokonaisuudessaan. Tutkielmassa käytetään konkreettisena esimerkkinä yrityksestä kontrolloida tilaa Helsingin kaupungin Stop Töhryille -projektia: kyseessä on tapaustutkimus em. projektista. Projekti toteutettiin vuosina 1998–2008 Helsingin kaupungin rakennusviraston sekä yleisten töiden lautakunnan alaisuudessa. Projektin tavoitteena oli vähentää ja poistaa kaupunkitilassa näkyviä graffiteja. Keinoina tähän oli tekninen siivous, valvonta ja viestintä. Graffitit voidaan nähdä yhtenä keinona vallata tilaa itselle. Tutkimuksen ongelmanasettelun taustalla on pohdinta siitä, kohdistuuko julkisen tilan kontrolli jonkin tietyn toiminnon ei-toivottavuuteen vai kohdistuuko kontrolli tiettyjen toimijoiden ei-toivottavuuteen. Tavoitteena on selvittää, minkälainen tilan kontrolliin tähtäävä ohjelma Stop Töhryille -projekti oli. Tutkimuskysymykset liittyvät siihen, miksi projekti toteutettiin, mihin projektin toimenpiteet kohdistuivat ja miten nollatoleranssi määriteltiin projektissa. Tutkielman teoreettinen viitekehys pohjautuu Jock Youngin määritelmälle nollatoleranssista, nollatoleranssin kritiikille sekä Henri Lefebvren, Don Mitchellin, Andrea Sharkeyn ja Rob Shieldsin kirjoituksiin oikeudesta tilaan. Aineistona käytetään yleisten töiden lautakunnan kokousten esityslista- ja pöytäkirjamateriaalia sekä haastatteluja projektissa mukana olleille tai projektiin vaikuttaneille tahoille (N=4). Analyysin menetelmänä sovelletaan diskurssianalyysiä. Aineiston perusteella voidaan todeta, että projektissa hyödynnettiin laajasti erilaisia kontrollin keinoja. Projektin toimenpiteet keskittyivät alussa enemmän toimintoon (graffitien puhdistamiseen ja ehkäisyyn), mutta viimeisinä vuosina painopiste siirtyi enemmän toimijaan (graffitintekijään). Aineiston analyysissä yhtenä olennaisena toimijaryhmänä esille nousivat nuoret ja nuoriso, jotka mainittiin useaan otteeseen graffitintekijöinä. Tutkielmassa tätä ilmiötä pohditaan Mike Presdeen nuoruuden kriminalisointi -käsitteen sekä Zygmunt Baumanin ulossulkemisen paradigman kautta. Nollatoleranssiretoriikka on löydettävissä projektista kolmella tasolla: ideologisella, toiminnallisella sekä viestinnällisellä. Nollatoleranssia perusteltiin ideologisella tasolla rikottujen ikkunoiden teesillä: pieniä sosiaalisia häiriöitä poistamalla voidaan ehkäistä suuria rikoksia. Tämä perustelu vietiin toiminnalliselle tasolle, jossa häiriökäyttäytyjiä valvottiin ja heille vaadittiin kovia rangaistuksia. Viestinnällä pyrittiin madaltamaan kansalaisten sietokykyä graffiti-ilmiöön ja edesautettiin mahdollisimman laajan kansalais- ja asukasyhteistyön syntymistä. Lisäksi projektissa luotiin aktiivisesti tiedon ja kielen politiikkaa, joissa tuotetaan käsitystä siitä että graffitit lisäävät turvattomuutta ja konstruoidaan sellainen kieli, jossa graffitit nähdään ongelmana.
Resumo:
The goal of the single building information model has existed for at least thirty years and various standards have been published leading up to the ten-year development of the Industry Foundation Classes. These have been initiatives from researchers, software developers and standards committees. Now large property owners are becoming aware of the benefits of moving IT tools from specific applications towards more comprehensive solutions. This study addresses the state of Building Information Models and the conditions necessary for them to become more widely used. It is a qualitative study based on information from a number of international experts and has asked a series of questions about the feasibility of BIMs, the conditions necessary for their success, and the role of standards with particular reference to the IFCs. Some key statements were distilled from the diverse answers received and indicate that BIM solutions appear too complex for many and may need to be applied in limited areas initially. Standards are generally supported but not applied rigorously and a range of these are relevant to BIM. Benefits will depend upon the building procurement methods used and there should be special roles within the project team to manage information. Case studies are starting to appear and these could be used for publicity. The IFCs are rather oversold and their complexities should be hidden within simple-to-use software. Inevitably major questions remain and property owners may be the key to answering some of these. A framework for presenting standards, backed up by case studies of successful projects, is the solution proposed to provide better information on where particular BIM standards and solutions should be applied in building projects.
Resumo:
One of the central issues in making efficient use of IT in the design, construction and maintenance of buildings is the sharing of the digital building data across disciplines and lifecycle stages. One technology which enables data sharing is CAD layering, which to be of real use requires the definition of standards. This paper focuses on the background, objectives and effectiveness of the International standard ISO 13567, Organisation and naming of layers for CAD. In particular the efficiency and effectiveness of the standardisation and standard implementation process are in focus, rather than the technical details. The study was conducted as a qualitative study with a number of experts who responded to a semi-structured mail questionnaire, supplemented by personal interviews. The main results were that CAD layer standards based on the ISO standard have been implemented, particularly in northern European countries, but are not very widely used. A major problem which was identified was the lack of resources for marketing and implementing the standard as national variations, once it had been formally accepted.
Resumo:
Tämä tutkielma keskittyy julkisen kaupunkitilan kontrollin eri muotoihin. Ihmiset käyttävät kaupunkitilaa eri tavoin ja eri tarkoituksiin. Tilan sallitut ja kielletyt käyttömuodot ovat aina erilaisten toiveiden yhteensovittamista: yhteisen neuvottelun tulos. Tilaa myös kontrolloidaan vastaamaan erilaisia toiveita ja odotuksia. Tutkielmassa julkisen tilan kontrollin muodot on jaettu kolmeen: tilan fyysinen muokkaaminen, tilan valvonta ja asenteisiin vaikuttaminen esimerkiksi politiikkaohjelmilla. Tärkeimpänä kiinnostuksen kohteena on tilanne, jossa jokin toiminta kielletään kokonaisuudessaan. Tutkielmassa käytetään konkreettisena esimerkkinä yrityksestä kontrolloida tilaa Helsingin kaupungin Stop Töhryille -projektia: kyseessä on tapaustutkimus em. projektista. Projekti toteutettiin vuosina 1998–2008 Helsingin kaupungin rakennusviraston sekä yleisten töiden lautakunnan alaisuudessa. Projektin tavoitteena oli vähentää ja poistaa kaupunkitilassa näkyviä graffiteja. Keinoina tähän oli tekninen siivous, valvonta ja viestintä. Graffitit voidaan nähdä yhtenä keinona vallata tilaa itselle. Tutkimuksen ongelmanasettelun taustalla on pohdinta siitä, kohdistuuko julkisen tilan kontrolli jonkin tietyn toiminnon ei-toivottavuuteen vai kohdistuuko kontrolli tiettyjen toimijoiden ei-toivottavuuteen. Tavoitteena on selvittää, minkälainen tilan kontrolliin tähtäävä ohjelma Stop Töhryille -projekti oli. Tutkimuskysymykset liittyvät siihen, miksi projekti toteutettiin, mihin projektin toimenpiteet kohdistuivat ja miten nollatoleranssi määriteltiin projektissa. Tutkielman teoreettinen viitekehys pohjautuu Jock Youngin määritelmälle nollatoleranssista, nollatoleranssin kritiikille sekä Henri Lefebvren, Don Mitchellin, Andrea Sharkeyn ja Rob Shieldsin kirjoituksiin oikeudesta tilaan. Aineistona käytetään yleisten töiden lautakunnan kokousten esityslista- ja pöytäkirjamateriaalia sekä haastatteluja projektissa mukana olleille tai projektiin vaikuttaneille tahoille (N=4). Analyysin menetelmänä sovelletaan diskurssianalyysiä. Aineiston perusteella voidaan todeta, että projektissa hyödynnettiin laajasti erilaisia kontrollin keinoja. Projektin toimenpiteet keskittyivät alussa enemmän toimintoon (graffitien puhdistamiseen ja ehkäisyyn), mutta viimeisinä vuosina painopiste siirtyi enemmän toimijaan (graffitintekijään). Aineiston analyysissä yhtenä olennaisena toimijaryhmänä esille nousivat nuoret ja nuoriso, jotka mainittiin useaan otteeseen graffitintekijöinä. Tutkielmassa tätä ilmiötä pohditaan Mike Presdeen nuoruuden kriminalisointi -käsitteen sekä Zygmunt Baumanin ulossulkemisen paradigman kautta. Nollatoleranssiretoriikka on löydettävissä projektista kolmella tasolla: ideologisella, toiminnallisella sekä viestinnällisellä. Nollatoleranssia perusteltiin ideologisella tasolla rikottujen ikkunoiden teesillä: pieniä sosiaalisia häiriöitä poistamalla voidaan ehkäistä suuria rikoksia. Tämä perustelu vietiin toiminnalliselle tasolle, jossa häiriökäyttäytyjiä valvottiin ja heille vaadittiin kovia rangaistuksia. Viestinnällä pyrittiin madaltamaan kansalaisten sietokykyä graffiti-ilmiöön ja edesautettiin mahdollisimman laajan kansalais- ja asukasyhteistyön syntymistä. Lisäksi projektissa luotiin aktiivisesti tiedon ja kielen politiikkaa, joissa tuotetaan käsitystä siitä että graffitit lisäävät turvattomuutta ja konstruoidaan sellainen kieli, jossa graffitit nähdään ongelmana.
Resumo:
To reduce the cost of disposal of large quantities of fly ash generated and environmental problems associated with it, efforts are made to utilize fly ash for geotechnical applications. Geotechnical properties of fly ash play a key role in enhancing their application. Physical properties and chemical composition control the index properties arid engineering behaviour. The paper brings out the rob of surface area, surface characteristics, reactive silica and lime content of fly ashes on index, compaction, consolidation and strength properties of fly ashes.
Resumo:
Sport hunting is often proposed as a tool to support the conservation of large carnivores. However, it is challenging to provide tangible economic benefits from this activity as an incentive for local people to conserve carnivores. We assessed economic gains from sport hunting and poaching of leopards (Panthera pardus), costs of leopard depredation of livestock, and attitudes of people toward leopards in Niassa National Reserve, Mozambique. We sent questionnaires to hunting concessionaires (n = 8) to investigate the economic value of and the relative importance of leopards relative to other key trophy-hunted species. We asked villagers (n = 158) the number of and prices for leopards poached in the reserve and the number of goats depredated by leopard. Leopards were the mainstay of the hunting industry; a single animal was worth approximately U.S.$24,000. Most safari revenues are retained at national and international levels, but poached leopard are illegally traded locally for small amounts ($83). Leopards depredated 11 goats over 2 years in 2 of 4 surveyed villages resulting in losses of $440 to 6 households. People in these households had negative attitudes toward leopards. Although leopard sport hunting generates larger gross revenues than poaching, illegal hunting provides higher economic benefits for households involved in the activity. Sport-hunting revenues did not compensate for the economic losses of livestock at the household level. On the basis of our results, we propose that poaching be reduced by increasing the costs of apprehension and that the economic benefits from leopard sport hunting be used to improve community livelihoods and provide incentives not to poach.
Resumo:
Most ecosystems have multiple predator species that not only compete for shared prey, but also pose direct threats to each other. These intraguild interactions are key drivers of carnivore community structure, with ecosystem-wide cascading effects. Yet, behavioral mechanisms for coexistence of multiple carnivore species remain poorly understood. The challenges of studying large, free-ranging carnivores have resulted in mainly coarse-scale examination of behavioral strategies without information about all interacting competitors. We overcame some of these challenges by examining the concurrent fine-scale movement decisions of almost all individuals of four large mammalian carnivore species in a closed terrestrial system. We found that the intensity of intraguild interactions did not follow a simple hierarchical allometric pattern, because spatial and behavioral tactics of subordinate species changed with threat and resource levels across seasons. Lions (Panthera leo) were generally unrestricted and anchored themselves in areas rich in not only their principal prey, but also, during periods of resource limitation (dry season), rich in the main prey for other carnivores. Because of this, the greatest cost (potential intraguild predation) for subordinate carnivores was spatially coupled with the highest potential benefit of resource acquisition (prey-rich areas), especially in the dry season. Leopard (P. pardus) and cheetah (Acinonyx jubatus) overlapped with the home range of lions but minimized their risk using fine-scaled avoidance behaviors and restricted resource acquisition tactics. The cost of intraguild competition was most apparent for cheetahs, especially during the wet season, as areas with energetically rewarding large prey (wildebeest) were avoided when they overlapped highly with the activity areas of lions. Contrary to expectation, the smallest species (African wild dog, Lycaon pictus) did not avoid only lions, but also used multiple tactics to minimize encountering all other competitors. Intraguild competition thus forced wild dogs into areas with the lowest resource availability year round. Coexistence of multiple carnivore species has typically been explained by dietary niche separation, but our multi-scaled movement results suggest that differences in resource acquisition may instead be a consequence of avoiding intraguild competition. We generate a more realistic representation of hierarchical behavioral interactions that may ultimately drive spatially explicit trophic structures of multi-predator communities.
Resumo:
Elephant are considered major drivers of ecosystems, but their effects within small-scale landscape features and on other herbivores still remain unclear. Elephant impact on vegetation has been widely studied in areas where elephant have been present for many years. We therefore examined the combined effect of short-term elephant presence (< 4 years) and hillslope position on tree species assemblages, resource availability, browsing intensity and soil properties. Short-term elephant presence did not affect woody species assemblages, but did affect height distribution, with greater sapling densities in elephant access areas. Overall tree and stem densities were also not affected by elephant. By contrast, slope position affected woody species assemblages, but not height distributions and densities. Variation in species assemblages was statistically best explained by levels of total cations, Zinc, sand and clay. Although elephant and mesoherbivore browsing intensities were unaffected by slope position, we found lower mesoherbivore browsing intensity on crests with high elephant browsing intensity. Thus, elephant appear to indirectly facilitate the survival of saplings, via the displacement of mesoherbivores, providing a window of opportunity for saplings to grow into taller trees. In the short-term, effects of elephant can be minor and in the opposite direction of expectation. In addition, such behavioural displacement promotes recruitment of saplings into larger height classes. The interaction between slope position and elephant effect found here is in contrast with other studies, and illustrates the importance of examining ecosystem complexity as a function of variation in species presence and topography. The absence of a direct effect of elephant on vegetation, but the presence of an effect on mesoherbivore browsing, is relevant for conservation areas especially where both herbivore groups are actively managed.
Resumo:
Analisa as implicações técnicas, sociais e legais da oferta, por operadoras de telefonia celular, de serviço de acesso a conteúdo produzido por emissoras de radiodifusão e outras produtoras, nas modalidades transmissão ao vivo (streaming) e descarga de conteúdo sob-demanda (ou download de vídeo on-demand).
Resumo:
Verifica possíveis consequências da exposição à radiação eletromagnética sobre a saúde humana, com enfoque especial à radiação gerada pela telefonia celular.