577 resultados para logit-malli


Relevância:

60.00% 60.00%

Publicador:

Resumo:

Maataloudessa on menossa rakennekehitys, jonka seurauksena tilojen määrä vähenee, mutta tuotannossa olevan pellon määrä ei kuitenkaan laske. Aktiivitilojen kasvu perustuu ennestään pieniin lohkoihin, jotka ovat etäällä toisistaan. Epäedullinen tilusrakenne vaikeuttaa olennaisesti tuotantoaan kehittävien aktiivitilojen tuottavuuskehitystä ja kannattavuustavoitteiden saavuttamista. Tilusjärjestelyiden tavoitteena on järjestää pellonomistajien pirstoutuneita tiluksia isoimmiksi lohkoiksi ja näin edesauttaa parempaan tilusrakenteeseen. Tilusjärjestely tehdään aina pellonomistajien pyynnöstä ja yhteistyössä maanmittaustoimiston kanssa. Tutkimuksen tavoitteena on koota aineisto, jonka avulla voitiin arvioida pellonomistajien asenteita pellon tilusjärjestelyitä kohtaan. Tutkimuksessa sekä kuvattiin että mallinnettiin pellonomistajien tietoisuutta ja asenteita liittyen tilusjärjestelyiden tarpeellisuuteen. Erityisesti huomiota kiinnitettiin tekijöihin, jotka selittivät pellonomistajien myönteisiä ja kielteisiä asenteita pellon tilusjärjestelyitä kohtaan. Tutkimusaineistona käytettiin rekisteriaineistoa sekä postikyselyaineistoa, joka on MTT Taloustutkimuksen toimesta yhdistetty yhdeksi suureksi Suomalainen pellonomistaja-aineistoksi. Lähtökohtana mallintamiseen käytettiin Suomalainen pellonomistaja aineistosta saatavia pellonomistajaa kuvaavia tekijöitä, jotka korreloivat tilusjärjestelyhalukkuuden kanssa. Mallintamiseen käytettiin logit-mallia. Tutkimuksen kannalta tärkein tulos oli, että isojen tilojen omistajat olivat tietoisempia pellon tilusjärjestelyistä kuin pienten tilojen omistajat. Pienemmissä tilasuuruusluokissa pellonomistus liittyy usein harrastusviljelyyn sekä pellon poisvuokraukseen. Maa- ja metsätalousyrittäjät olivat tietoisimpia tilusjärjestelyistä kuin eläkeläiset ja palkansaajat. Suurin osa pelloista on sellaisten pellonomistajien omistuksessa, jotka eivät itse määrittele itseään viljelijöiksi. Tämän kehityssuunnan oletetaan jatkuvan, joten pellonomistajien tilusjärjestelytietoisuuden voidaan olettaa heikkenevän tulevaisuudessa. Pellonomistajien asenteet pellon tilusjärjestelyihin eivät ole homogeeniset. Tutkimuksessa selvisi uutena tietona se, että maataloustuloa painottavat pellonomistajat ja maataloutta edistävät tilat suhtautuivat tilusjärjestelyyn myönteisemmin kuin muut.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Tutkimuksen tavoitteena oli tutkia vähittäiskaupan lähiruokavalikoiman ja asiakasuskollisuuden yhteyttä. Elintarvikemarkkinoilla kilpailijoista erilaistettuja toimintamalleja tulee kehittää kohdemarkkinoiden muutokset huomioiden. Yhteiskunnalliset muutokset ja kasvava kuluttajakysyntä osoittavat lähiruokamarkkinan kasvupotentiaalia. Lähiruokamarkkinoiden ollessa elinkaarensa alkuvaiheessa voi lähiruoka toimintamallin kehittäminen mahdollistaa vähittäiskauppaympäristön erilaistamisen ja valikoimien kehittämisen asiakasuskollisuuden parantamiseksi sekä kilpailukyvyn säilyttämiseksi. Tutkimuksen teoriaosassa tarkastellaan lähiruokajärjestelmää elintarvikemarkkinoiden kontekstista ja vähittäiskaupan näkökulmasta. Asiakasuskollisuutta tarkastellaan aikaisempien määritelmien pohjalta ja liiketoiminnallisesta näkökulmasta. Tutkimuksen empiriaosan vaatimukset huomioiden keskityttiin erityisesti käyttäytymispohjaisen asiakasuskollisuuden teoriapohjaan. Tutkimuksen empiriaosassa lähiruokavalikoiman vaikutus asiakasuskollisuuteen rajattiin koskemaan leipäosaston valikoimarakennetta. Tutkimuksessa myymäläkohtaisen asiakasuskollisuuden mittaamisen mahdollistaa yhteistyöyrityksen asiakastietokannan talouskohtaiset ostohistoriatiedot, jotka perustuvat ostotapahtuman yhteydessä käytettyyn kanta-asiakaskorttiin. Lähileipävalikoimarakennetta ja asiakasuskollisuutta tarkasteltiin 39 myymälän aineistolla syysmarraskuun 2010 tarkastelujaksolla. Myymäläkohtaiset kyselylomaketiedot valikoimarakenteesta ja asiakastietokantatiedot mahdollistavat kvantitatiivisen tutkimusotteen hyödyntämisen. Pääanalyysin tilastollisena menetelmänä käytettiin Logit-mallia. Logit-malli mahdollisti myymäläkohtaisen asiakasluokka- ja leipävalikoimarakenteen riippuvuuden analysoinnin. Tutkimuksen pääanalyysin tuloksien perusteella myymälän pääostopaikka-asiakkaista uskollisten asiakkaiden osuus kasvaa, mutta myös täydennysostopaikka-asiakkaiden osuus asioineista talouksista lisääntyy lähileipävalikoiman suhteellisen osuuden kasvaessa. Lisäksi uskollisten asiakasryhmien tarkempi analyysi osoitti, että myymälän lähileipävalikoimaosuuden ja myymälän avainasiakasosuuden välillä ilmeni positiivinen yhteys. Tutkimustuloksia voidaan pitää kaupallisesti mielenkiintoisina ja tulosten taustalla vaikuttavat tekijät sekä liiketoiminnalliset mahdollisuudet vaativat jatkotutkimusta.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Statisticians along with other scientists have made significant computational advances that enable the estimation of formerly complex statistical models. The Bayesian inference framework combined with Markov chain Monte Carlo estimation methods such as the Gibbs sampler enable the estimation of discrete choice models such as the multinomial logit (MNL) model. MNL models are frequently applied in transportation research to model choice outcomes such as mode, destination, or route choices or to model categorical outcomes such as crash outcomes. Recent developments allow for the modification of the potentially limiting assumptions of MNL such as the independence from irrelevant alternatives (IIA) property. However, relatively little transportation-related research has focused on Bayesian MNL models, the tractability of which is of great value to researchers and practitioners alike. This paper addresses MNL model specification issues in the Bayesian framework, such as the value of including prior information on parameters, allowing for nonlinear covariate effects, and extensions to random parameter models, so changing the usual limiting IIA assumption. This paper also provides an example that demonstrates, using route-choice data, the considerable potential of the Bayesian MNL approach with many transportation applications. This paper then concludes with a discussion of the pros and cons of this Bayesian approach and identifies when its application is worthwhile

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Motorcycles are particularly vulnerable in right-angle crashes at signalized intersections. The objective of this study is to explore how variations in roadway characteristics, environmental factors, traffic factors, maneuver types, human factors as well as driver demographics influence the right-angle crash vulnerability of motorcycles at intersections. The problem is modeled using a mixed logit model with a binary choice category formulation to differentiate how an at-fault vehicle collides with a not-at-fault motorcycle in comparison to other collision types. The mixed logit formulation allows randomness in the parameters and hence takes into account the underlying heterogeneities potentially inherent in driver behavior, and other unobserved variables. A likelihood ratio test reveals that the mixed logit model is indeed better than the standard logit model. Night time riding shows a positive association with the vulnerability of motorcyclists. Moreover, motorcyclists are particularly vulnerable on single lane roads, on the curb and median lanes of multi-lane roads, and on one-way and two-way road type relative to divided-highway. Drivers who deliberately run red light as well as those who are careless towards motorcyclists especially when making turns at intersections increase the vulnerability of motorcyclists. Drivers appear more restrained when there is a passenger onboard and this has decreased the crash potential with motorcyclists. The presence of red light cameras also significantly decreases right-angle crash vulnerabilities of motorcyclists. The findings of this study would be helpful in developing more targeted countermeasures for traffic enforcement, driver/rider training and/or education, safety awareness programs to reduce the vulnerability of motorcyclists.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A rule of thumb is suggested for comparing multinomial logit coefficients with multinomial probit coefficients in the special case where the normal errors are distributed N(0,1). The rule is a generalization of the '1.6' rule for comparing logit and probit coefficients. © 1989.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Public acceptance is consistently listed as having an enormous impact on the implementation and success of a congestion charge scheme. This paper investigates public acceptance of such a scheme in Australia. Surveys were conducted in Brisbane and Melbourne, the two fastest growing Australian cities. Using an ordered logit modeling approach, the survey data including stated preferences were analyzed to pinpoint the important factors influencing people’s attitudes to a congestion charge and, in turn, to their transport mode choices. To accommodate the nature of, and to account for the resulting heterogeneity of the panel data, random effects were considered in the models. As expected, this study found that the amount of the congestion charge and the financial benefits of implementing it have a significant influence on respondents’ support for the charge and on the likelihood of their taking a bus to city areas. However, respondents’ current primary transport mode for travelling to the city areas has a more pronounced impact. Meanwhile, respondents’ perceptions of the congestion charge’s role in protecting the environment by reducing vehicle emissions, and of the extent to which the charge would mean that they travelled less frequently to the city for shopping or entertainment, also have a significant impact on their level of support for its implementation. We also found and explained notable differences across two cities. Finally, findings from this study have been fully discussed in relation to the literature.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper introduces the smooth transition logit (STL) model that is designed to detect and model situations in which there is structural change in the behaviour underlying the latent index from which the binary dependent variable is constructed. The maximum likelihood estimators of the parameters of the model are derived along with their asymptotic properties, together with a Lagrange multiplier test of the null hypothesis of linearity in the underlying latent index. The development of the STL model is motivated by the desire to assess the impact of deregulation in the Queensland electricity market and ascertain whether increased competition has resulted in significant changes in the behaviour of the spot price of electricity, specifically with respect to the occurrence of periodic abnormally high prices. The model allows the timing of any change to be endogenously determined and also market participants' behaviour to change gradually over time. The main results provide clear evidence in support of a structural change in the nature of price events, and the endogenously determined timing of the change is consistent with the process of deregulation in Queensland.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The study analyses European social policy as a political project that proceeds under the guidance of the European Commission. In the name of modernisation, the project aims to build a new idea for the welfare state. To understand the project, it is necessary to distance oneself from both the juridical competence of the European Union and the traditional national welfare state models. The question is about sharing problems, as well as solutions to them: it is the creation and sharing of common views, concepts and images that play a key role in European integration. Drawing on texts and speeches produced by the European Commission, the study throws light on the development of European social policy during the first years of the 2000s. The study "freeze-frames" the welfare debate having its starting points in the nation states in the name of the entity of Europe. The first article approaches the European social model as a story in itself, a preparatory, persuasive narrative that concerns the management of change. The article shows how the audience can be motivated to work towards a set target by using discursive elements in a persuasive manner: the function of a persuasive story is to convince the target audience of the appropriateness of the chosen direction and to shape their identity so that they are favourably disposed to the desired political targets. This is a kind of "intermediate state" where the story, despite its inner contradictions and inaccuracies, succeeds in appearing as an almost self-evident path towards a modern social policy that Europe is currently seen to be in need of. The second article outlines the European social model as a question of governance. Health as a sector of social policy is detached from the old political order, which was based on the welfare state, and is closely linked to economy. At the same time the population is primarily seen as an economic resource. The Commission is working towards a "Europe of Health" that grapples with the problem of governance with the help of the "healthisation" of society, healthy citizenship and health economics. The way the Commission speaks is guided by the Union's powerful interest to act as "Europe" in the field of welfare policy. At the same time, the traditional separateness of health policy is effaced in order to be able to make health policy reforms a part of the Union's wider modernisation targets. The third article then shows the European social policy as its own area of governance. The article uses an approach based on critical discourse analysis in examining the classification systems and presentation styles adopted by Commission communications, as well as the identities that they help build. In analysing the "new start" of the Lisbon strategy from the perspective of social policy, the article shows how the emphasis has shifted from the persuasive arguments for change with necessary common European targets in the early stages of the strategy towards the implementation of reforms: from a narrative to a vision and from a diagnosis to healing. The phase of global competition represents "the modern" with which European society with its culture and ways of life now has to be matched. The Lisbon strategy is a way to direct this societal change, thus building a modern European social policy. The fourth article describes how the Commission uses its communications policy to build practices and techniques of governance and how it persuades citizens to participate in the creation of a European project of change. This also requires a new kind of agency: agents for whom accountability and responsibilities mean integration into and commitment to European society. Accountability is shaped into a decisive factor in implementing the European Union's strategy of change. As such it will displace hierarchical confrontations and emphasise common action with a view to modernising Europe. However, the Union's discourse cannot be described as being a political language that would genuinely rouse and convince the audience at the level of everyday life. Keywords: European social policy, EU policy, European social model, European Commission, modernisation of welfare, welfare state, communications, discoursiveness.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The subject matter of this study is the cultural knowledge concerning romantic male-female relationships in autobiographies written by so called ordinary Finnish men and women born between 1901 and 1965. The research data (98 autobiographies) is selected from two collections by the Finnish Literature Society s folklore archives in the early 1990 s. Autobiographies are cultural representations where negotiation of shared cultural models and personal meanings given to hetero-relationship is evident in an interesting manner. In this research I analyze autobiographies as a written folklore genre. Information concerning male-female relationships is being analyzed using theoretically informed close readings thematic analysis, intertextual reading and reflexive reading. Theoretical implications stem from cognitive anthropology (the idea of cultural models) and an adaptation of discourse theory inspired by Michel Foucault. The structure of the analysis follows the structure of the shared knowledge concerning romantic male-female relationship: the first phase of analysis presents the script of a hetero-relationship and then moves into the actual structure, the cultural model of a relationship. The components of the model of relationship are, as mentioned in the title of the research, woman, man, love and sex. The research shows that all the writers share this basic knowledge concerning a heterosexual relationship despite their age, background or gender. Also the conflicts described and experienced in the relationships of the writers were similar throughout the timespan of the early 1900 s to 1990 s: lack of love, inability to reconcile sexual desires, housework, sharing the responsibility of childcare and financial problems. The research claims that the conflicts in relationships are a major cause for the binary view on gender. When relationships are harmonious, there seems to be no need to see men and women as opposites. The research names five important discourses present in the meaning giving processes of autobiographers. In doing so, the stabile cultural model of male-female relationship widens to show the complexity and variation in data. In this way it is possible to detect some age and gender specific shifts and emphasis. The discourses give meaning to the components of the cultural model and determine the contents of womanhood, manhood, sexuality and love. The way these discourses are spread and their authority are different: the romantic discourse evident in the autobiographies appeal to the authority of love supreme love is the purpose of male-female relationship and it justifies sexuality. In this discourse sex can be the place for confluence of genders. The ideas of romantic love are widely spread in popular culture. Popular scientific discourse defines a relationship as a site to become a man and a woman either from a psychological or a biological point of view. Genders are seen as opposites. These ideas are often presented in media and their authority in science which is seen as infallible. The Christian discourse defines men and women: both should work for the benefit of the nuclear family under the undisputed authority of God. Marital love is based on Christian virtues and within marriage sexuality is acceptable. The discourse I ve named folk tradition defines women and men as guardians of home and offspring. The authority of folk tradition comes from universal truth based in experience and truths known to the mediators of this discourse grandparents, parents and other elders or peers. Societal discourse defines the hetero relationship as the mainstay of society. The authority in societal discourse stems from the laws and regulations that control relationship practices.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Veri-aivoeste suojelee aivoja verenkierron vierasaineilta. Veri-aivoestettä tutkivia in vivo ja in vitro -menetelmiä on raportoitu laajasti kirjallisuudessa. Yhdisteiden farmakokinetiikka aivoissa kuvaavia tietokonemalleja on esitetty vain muutamia. Tässä tutkimuksessa kerättiin kirjallisuudesta aineisto eri in vitro ja in vivo -menetelmillä määritetyistä veri-aivoesteen permeabiliteettikertoimista. Lisäksi tutkimuksessa rakennettiin kaksi veri-aivoesteen farmakokineettista tietokonemallia, mikrodialyysimalli ja efluksimalli. Mikrodialyysimalli on yksinkertainen kahdesta tilasta (verenkierto ja aivot) koostuva farmakokineettinen malli. Mikrodialyysimallilla simuloitiin in vivo määritettyjen parametrien perusteella viiden yhdisteen pitoisuuksia rotan aivoissa ja verenkierrossa. Mallilla ei saatu täsmällisesti in vivo -tilannetta vastaavia pitoisuuskuvaajia johtuen mallin rakenteessa tehdyistä yksinkertaistuksista, kuten aivokudostilan ja kuljetinproteiinien kinetiikan puuttuminen. Efluksimallissa on kolme tilaa, verenkierto, veri-aivoesteen endoteelisolutila ja aivot. Efluksimallilla tutkittiin teoreettisten simulaatioiden avulla veri-aivoesteen luminaalisella membraanilla sijaitsevan aktiivisen efluksiproteiinin ja passiivisen permeaation merkitystä yhdisteen pitoisuuksiin aivojen solunulkoisessa nesteessä. Tutkittava parametri oli vapaan yhdisteen pitoisuuksien suhde aivojen ja verenkierron välillä vakaassa tilassa (Kp,uu). Tuloksissa havaittiin efluksiproteiinin vaikutus pitoisuuksiin Michaelis-Mentenin kinetiikan mukaisesti. Efluksimalli sopii hyvin teoreettisten simulaatioiden tekemiseen. Malliin voidaan lisätä aktiivisia kuljettimia. Teoreettisten simulaatioiden avulla voidaan yhdistää in vitro ja in vivo tutkimuksien tuloksia ja osatekijöitä voidaan tutkia yhdessä simulaatiossa.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

[ES] La influencia que las características individuales del personal de una empresa ejercen sobre su nivel de satisfacción laboral ha sido ampliamente analizada en la literatura al respecto, dedicando una especial atención a la variable edad pero también al género como un elemento determinante de los niveles de satisfacción de los recursos humanos. En numerosas investigaciones se constata que las mujeres presentan un nivel superior de satisfacción al de los varones.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper reports the findings from a discrete-choice experiment designed to estimate the economic benefits associated with rural landscape improvements in Ireland. Using a mixed logit model, the panel nature of the dataset is exploited to retrieve willingness-to-pay values for every individual in the sample. This departs from customary approaches in which the willingness-to-pay estimates are normally expressed as measures of central tendency of an a priori distribution. Random-effects models for panel data are subsequently used to identify the determinants of the individual-specific willingness-to-pay estimates. In comparison with the standard methods used to incorporate individual-specific variables into the analysis of discrete-choice experiments, the analytical approach outlined in this paper is shown to add considerable explanatory power to the welfare estimates.