953 resultados para What-if Analysis
Resumo:
This paper investigates what has caused output and inflation volatility to fall in the USusing a small scale structural model using Bayesian techniques and rolling samples. Thereare instabilities in the posterior of the parameters describing the private sector, the policyrule and the standard deviation of the shocks. Results are robust to the specification ofthe policy rule. Changes in the parameters describing the private sector are the largest,but those of the policy rule and the covariance matrix of the shocks explain the changes most.
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Trees are a great bank of data, named sometimes for this reason as the "silentwitnesses" of the past. Due to annual formation of rings, which is normally influenced directly by of climate parameters (generally changes in temperature and moisture or precipitation) and other environmental factors; these changes, occurred in the past, are"written" in the tree "archives" and can be "decoded" in order to interpret what hadhappened before, mainly applied for the past climate reconstruction.Using dendrochronological methods for obtaining samples of Pinus nigra fromthe Catalonian PrePirineous region, the cores of 15 trees with total time spine of about 100 - 250 years were analyzed for the tree ring width (TRW) patterns and had quite high correlation between them (0.71 ¿ 0.84), corresponding to a common behaviour for the environmental changes in their annual growth.After different trials with raw TRW data for standardization in order to take outthe negative exponential growth curve dependency, the best method of doubledetrending (power transformation and smoothing line of 32 years) were selected for obtaining the indexes for further analysis.Analyzing the cross-correlations between obtained tree ring width indexes andclimate data, significant correlations (p<0.05) were observed in some lags, as forexample, annual precipitation in lag -1 (previous year) had negative correlation with TRW growth in the Pallars region. Significant correlation coefficients are between 0.27- 0.51 (with positive or negative signs) for many cases; as for recent (but very short period) climate data of Seu d¿Urgell meteorological station, some significant correlation coefficients were observed, of the order of 0.9.These results confirm the hypothesis of using dendrochronological data as aclimate signal for further analysis, such as reconstruction of climate in the past orprediction in the future for the same locality.
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INTRODUCTION: To determine if mulling, the process of adding tobacco to cannabis for its consumption, exposes young cannabis users to significant levels of nicotine. METHODS: This observational study performed in 2009-2010 among Swiss youths aged 16-25 years involved the completion of a self-administrated questionnaire and the collection of a urine sample on the same day. Measures of urinary cotinine were blindly performed using liquid chromatography coupled-mass spectrometry. A total of 197 eligible participants were divided in 3 groups based on their consumption profile in the past 5 days: 70 abstainers (ABS) not having used cigarettes or cannabis, 57 cannabis users adding tobacco to the cannabis they smoke (MUL) but not having smoked cigarettes, and 70 cigarette smokers (CIG) not having smoked cannabis. RESULTS: Exposure to nicotine was at its lowest among ABS with a mean (SE) cotinine level of 3.2 (1.4) ng/ml compared, respectively, with 214.6 (43.8) and 397.9 (57.4) for MUL and CIG (p < .001). While consumption profile appeared as the only significant factor of influence when examining nicotine exposure from the ABS and MUL participants on multivariate analysis, it did not result in substantial differences among MUL and CIG groups. CONCLUSIONS: Urinary cotinine levels found among MUL are high enough to indicate a significant exposure to nicotine originating from the mulling process. In line with our results, health professionals should pay attention to mulling as it is likely to influence cannabis and cigarette use as well as the efficacy of cessation interventions.
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This paper examines the existence of a habituation effect to unemployment: Do theunemployed suffer less from job loss if unemployment is more widespread, if their ownunemployment lasts longer and if unemployment is a recurrent experience? Theunderlying idea is that unemployment hysteresis may operate through a sociologicalchannel: if many people in the community lose their job and remain unemployed over anextended period, the psychological cost of being unemployed diminishes and the pressureto accept a new job declines. We analyze this question with individual-level data from theGerman Socio-Economic Panel (1984-2009) and the Swiss Household Panel (2000-2009). We find no evidence for a mitigating effect of high surrounding unemployment onunemployed individuals' subjective well-being: Becoming unemployed hurts as muchwhen regional unemployment is high as when it is low. Likewise, the strongly harmfulimpact of being unemployed on well-being does not wear off over time, nor do repeatedepisodes of unemployment make it any better. It thus appears doubtful that anunemployment shock becomes persistent because the unemployed become used to, andhence reasonably content with, being without a job.
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In the administration, planning, design, and maintenance of road systems, transportation professionals often need to choose between alternatives, justify decisions, evaluate tradeoffs, determine how much to spend, set priorities, assess how well the network meets traveler needs, and communicate the basis for their actions to others. A variety of technical guidelines, tools, and methods have been developed to help with these activities. Such work aids include design criteria guidelines, design exception analysis methods, needs studies, revenue allocation schemes, regional planning guides, designation of minimum standards, sufficiency ratings, management systems, point based systems to determine eligibility for paving, functional classification, and bridge ratings. While such tools play valuable roles, they also manifest a number of deficiencies and are poorly integrated. Design guides tell what solutions MAY be used, they aren't oriented towards helping find which one SHOULD be used. Design exception methods help justify deviation from design guide requirements but omit consideration of important factors. Resource distribution is too often based on dividing up what's available rather than helping determine how much should be spent. Point systems serve well as procedural tools but are employed primarily to justify decisions that have already been made. In addition, the tools aren't very scalable: a system level method of analysis seldom works at the project level and vice versa. In conjunction with the issues cited above, the operation and financing of the road and highway system is often the subject of criticisms that raise fundamental questions: What is the best way to determine how much money should be spent on a city or a county's road network? Is the size and quality of the rural road system appropriate? Is too much or too little money spent on road work? What parts of the system should be upgraded and in what sequence? Do truckers receive a hidden subsidy from other motorists? Do transportation professions evaluate road situations from too narrow of a perspective? In considering the issues and questions the author concluded that it would be of value if one could identify and develop a new method that would overcome the shortcomings of existing methods, be scalable, be capable of being understood by the general public, and utilize a broad viewpoint. After trying out a number of concepts, it appeared that a good approach would be to view the road network as a sub-component of a much larger system that also includes vehicles, people, goods-in-transit, and all the ancillary items needed to make the system function. Highway investment decisions could then be made on the basis of how they affect the total cost of operating the total system. A concept, named the "Total Cost of Transportation" method, was then developed and tested. The concept rests on four key principles: 1) that roads are but one sub-system of a much larger 'Road Based Transportation System', 2) that the size and activity level of the overall system are determined by market forces, 3) that the sum of everything expended, consumed, given up, or permanently reserved in building the system and generating the activity that results from the market forces represents the total cost of transportation, and 4) that the economic purpose of making road improvements is to minimize that total cost. To test the practical value of the theory, a special database and spreadsheet model of Iowa's county road network was developed. This involved creating a physical model to represent the size, characteristics, activity levels, and the rates at which the activities take place, developing a companion economic cost model, then using the two in tandem to explore a variety of issues. Ultimately, the theory and model proved capable of being used in full system, partial system, single segment, project, and general design guide levels of analysis. The method appeared to be capable of remedying many of the existing work method defects and to answer society's transportation questions from a new perspective.
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Euroopan unionissa päätettiin jo yli vuosikymmen sitten, että rautatieliiketoiminta vapautetaan kilpailulle. Iso-Britanniasta olimäärä tulla esimerkkivaltio tämän prosessin käyttöönotossa. Pääideana oli säännöstelyn keventäminen, jolloin omistuspohja toimialalla laajenee ja rautateiden infrastruktuuri sekä toiminta parantuvat. Infrastruktuuri on määrä olla yhden organisaation hallinnassa ja raiteiden käyttöoikeus on kaikilla lupaehdot täyttävillä operaattoreilla, jotka kilpailevat keskenään matkustajista ja tavararahdeista. Kuitenkin Yhdysvalloissa ja eräissä Latinalaisen Amerikan maissa kilpailu on vapautettu siten, että rautatieyritys omistaa raideinfrastruktuurin, junat, tavarankuljetus- sekä matkustajavaunut. Iso-Britannian yksityistämistä pidettiin aluksi isonaepäonnistumisena: nopealla aikataululla sovellettiin jäykkiä transaktioperusteisia ulkoistamisstrategioita infrastruktuurin kunnossapitoon, jotka lopulta johtivat junien jatkuviin myöhästymisiin ja muutamaan tuhoisaan onnettomuuteen. Liiketoiminnallisessa mielessäkään ei oikein onnistuttu: infrastruktuurista vastaava yritys jouduttiin listaamaan pois Lontoon pörssistä, ja hallituksen oli pakko luoda tukipaketti pahasti velkaantuneen, vain marginaalisien investointien kohteena olleen yrityksen toimintaa varten (vaikka kapasiteettitarvetta oli markkinoilla). Myös rautatieoperaattorit olivat taloudellisessa ahdingossa ja vain määrätietoisten hallituksen laatimien pelastuspakettien avulla ala nousi syvimmästä kriisistään. Tästä huolimatta näiden negatiivisten sivuvaikutusten ohella koko ala pystyi kasvattamaan kysyntää, niin matkustaja- kuin rahtiliikenteenkin osalta. Vähenevän kysynnän trendi, joka alkoi 1970-luvulla, otti käännöksen parempaan. Toinen eurooppalaismaa, jolla on pitkät kokemukset yksityistämisestä, on Ruotsi. Tämä maatapaus on melko konservatiivinen verrattuna tilanteeseen edellisessä; vain rajattu määrä reittejä on avattu kilpailulle ja sopimukset tehdään kerralla pitkäksi aikaa eteenpäin. Ruotsin säännöstelyn purku osoittautui menestykseksi, koska tuottavuus onollut vakaassa kasvussa ja rautateiden markkinaosuus erityisesti matkustajapuolella on noussut merkittävästi, verrattuna muihin kuljetusmuotoihin. Kuitenkin kilpailua on käytännössä vähän tässä maassa ja parempiatuloksia on lupa odottaa, kun vain säännöstelyn purkaminen jatkuu. Viimeinen tutkimuksemme kohteena oleva maa on Yhdysvallat, joka alistutti rautatiet kilpailulle jo 1980-luvun alussa, käyttäen jo edellä mainittua vertikaalista integraatiota; tämä valinta on taas johtanut hyvin erilaisiin tuloksiin. Vaihtoehtoinen rakenteellinen uudistustapa on suosinut rahtivirtoja matkustajiin nähden, ja lopputuloksena tämä tapaus synnytti yrityksiä huolehtimaan toista näistä kahdesta pääasiakasryhmästä. Viimeaikaiset tulokset tästä yksityistämisprosessista ovat olleet hyviä: jäljellejääneiden yritysten voitot ovat kasvaneet, osinkoja ollaan kyetty jakamaan ja osakkeiden arvostus on noussut. Tässä tutkimusraportissa yritämme kolmen maatapauksen kautta esittää, miten yksityistämisprosessi tulee vaikuttamaan Euroopassa, kun kilpailu rautateillä vapautuu. Me käymmeläpi, mikä näistä kolmesta maaesimerkistä on kaikkein todennäköisin jaesitämme ehdotuksia siihen, miten valtiot voisivat välttää ei-haluttuja sivuvaikutuksia. Kolme maaesimerkkiä, ja lopuksi esitetty lyhyt tilastollinen analyysi osoittavat, että rautateillä on tulevaisuuden potentiaalia Euroopassa, ja kilpailun vapauttaminen on avain tämän potentiaalin realisointiin.
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A variation of task analysis was used to build an empirical model of how therapists may facilitate client assimilation process, described in the Assimilation of Problematic Experiences Scale. A rational model was specified and considered in light of an analysis of therapist in-session performances (N = 117) drawn from six inpatient therapies for depression. The therapist interventions were measured by the Comprehensive Psychotherapeutic Interventions Rating Scale. Consistent with the rational model, confronting interventions were particularly useful in helping clients elaborate insight. However, rather than there being a small number of progress-related interventions at lower levels of assimilation, therapists' use of interventions was broader than hypothesized and drew from a wide range of therapeutic approaches. Concerning the higher levels of assimilation, there was insufficient data to allow an analysis of the therapist's progress-related interventions.
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In traffic accidents involving motorcycles, paint traces can be transferred from the rider's helmet or smeared onto its surface. These traces are usually in the form of chips or smears and are frequently collected for comparison purposes. This research investigates the physical and chemical characteristics of the coatings found on motorcycles helmets. An evaluation of the similarities between helmet and automotive coating systems was also performed.Twenty-seven helmet coatings from 15 different brands and 22 models were considered. One sample per helmet was collected and observed using optical microscopy. FTIR spectroscopy was then used and seven replicate measurements per layer were carried out to study the variability of each coating system (intravariability). Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were also performed on the infrared spectra of the clearcoats and basecoats of the data set. The most common systems were composed of two or three layers, consistently involving a clearcoat and basecoat. The coating systems of helmets with composite shells systematically contained a minimum of three layers. FTIR spectroscopy results showed that acrylic urethane and alkyd urethane were the most frequent binders used for clearcoats and basecoats. A high proportion of the coatings were differentiated (more than 95%) based on microscopic examinations. The chemical and physical characteristics of the coatings allowed the differentiation of all but one pair of helmets of the same brand, model and color. Chemometrics (PCA and HCA) corroborated classification based on visual comparisons of the spectra and allowed the study of the whole data set at once (i.e., all spectra of the same layer). Thus, the intravariability of each helmet and its proximity to the others (intervariability) could be more readily assessed. It was also possible to determine the most discriminative chemical variables based on the study of the PCA loadings. Chemometrics could therefore be used as a complementary decision-making tool when many spectra and replicates have to be taken into account. Similarities between automotive and helmet coating systems were highlighted, in particular with regard to automotive coating systems on plastic substrates (microscopy and FTIR). However, the primer layer of helmet coatings was shown to differ from the automotive primer. If the paint trace contains this layer, the risk of misclassification (i.e., helmet versus vehicle) is reduced. Nevertheless, a paint examiner should pay close attention to these similarities when analyzing paint traces, especially regarding smears or paint chips presenting an incomplete layer system.
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User retention is a major goal for higher education institutions running their teaching and learning programmes online. This is the first investigation into how the senses of presence and flow, together with perceptions about two central elements of the virtual education environment (didactic resource quality and instructor attitude), facilitate the user¿s intention to continue e-learning. We use data collected from a large sample survey of current users in a pure e-learning environment along with objective data about their performance. The results provide support to the theoretical model. The paper further offers practical suggestions for institutions and instructors who aim to provide effective e-learning experiences.
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The objective of the present study was to determine to what extent, if any, swimming training applied before immobilization in a cast interferes with the rehabilitation process in rat muscles. Female Wistar rats, mean weight 260.52 ± 16.26 g, were divided into 4 groups of 6 rats each: control, 6 weeks under baseline conditions; trained, swimming training for 6 weeks; trained-immobilized, swimming training for 6 weeks and then immobilized for 1 week; trained-immobilized-rehabilitated, swimming training for 6 weeks, immobilized for 1 week and then remobilized with swimming for 2 weeks. The animals were then sacrificed and the soleus and tibialis anterior muscles were dissected, frozen in liquid nitrogen and processed histochemically (H&E and mATPase). Data were analyzed statistically by the mixed effects linear model (P < 0.05). Cytoarchitectural changes such as degenerative characteristics in the immobilized group and regenerative characteristics such as centralized nucleus, fiber size variation and cell fragmentation in the groups submitted to swimming were more significant in the soleus muscle. The diameters of the lesser soleus type 1 and type 2A fibers were significantly reduced in the trained-immobilized group compared to the trained group (P < 0.001). In the tibialis anterior, there was an increase in the number of type 2B fibers and a reduction in type 2A fibers when trained-immobilized rats were compared to trained rats (P < 0.001). In trained-immobilized-rehabilitated rats, there was a reduction in type 2B fibers and an increase in type 2A fibers compared to trained-immobilized rats (P < 0.009). We concluded that swimming training did not minimize the deleterious effects of immobilization on the muscles studied and that remobilization did not favor tissue re-adaptation.
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The purpose of this thesis was to study change management and find out how the theory applies to practise with the help of studying an organizational change process. The goal was to investigate the different ways of the change management and how those could be utilized in practise. The purpose was also to see what kind of tools and information packages for change management the company involved has developed and taken in to use and check if these could have been utilized in the change process studied in this thesis. This thesis was established by studying the theory of change management and interviewing the people involved in the organizational change and the stakeholders. The questions were formed in line with the change management theory. The main theory used was John P. Kotter’s Eight Steps of Change. The study revealed valuable details about change processes in real life and concrete improvement ideas were recognized from the interviews. Overall the people were quite happy with the outcome of the change process. There were also some failures identified in this change process. Most probably those can be avoided in the future if people planning the change are familiar with the company’s new information packages and tools for change management. Change management is a complex area that is still today quite often forgotten by companies. Effective change management can give a huge competitive advantage for a company. Acknowledging that change process is always complex and not easy is already a good step forward in handling change processes. All changes need change management and understanding the way people react on change. A good and efficient change management is the key to make the change process smooth and easier for the people involved.
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As unregistered grassroots charities do not appear in official statistics in China, they tend to remain unnoticed by scholars. Also as they operate unofficially and avoid publicity, their work is usually not reported by the media. In this research I explore the grassroots charity activity of one pop music fan club from the viewpoint of trust as a sociological concept. I will also establish the general situation on charity in China. By using textual analysis on internet blogs and discussion forums I map the charity project from the discussion of the original idea to the execution and follow up phase. I study the roles the fan club members assume during the project as anonymous participants of internet conversations, as well as concrete active charity volunteers outside of the virtual world. I establish parties, other than the fan club, which are involved in the charity project. Interviews with one of the participant of the project in 2010, 2014 and 2015 bring valuable additional information and help in distributing the questionnaire survey. A quantitative questionnaire survey was distributed among the fan club members to get more detailed information on the motives and attitudes towards official and unofficial charity in China. Because of the inequality in China, the rural minority areas do not have similar educational opportunities as the mostly majority inhabited urban areas, even though the country officially has a nine year compulsory education. Grassroots charities can operate in relative freedom taking some of the government’s burden of social responsibilities if they are not criticizing the authorities. The problem with grassroots charity seems to be lack of sustainability. The lack of trust for authorities and official charities was the reason why the Jane Zhang fan club decided to conduct a charity case unofficially. As a group of people previously unknown to each other, they managed to build mutual trust to carry out the project transparently and successfully, though not sustainably. The internet has provided a new and effective platform for unofficial grassroots charities, who choose not to co-operate with official organisations. On grassroots level charities can have the transparency and trust that lack from official charities. I suggest, that interviewing the real persons behind the internet aliases and finding out what happened outside the discussion forums, would bring a more detailed and outspoken description of the project concerning of the contacts with the local authorities. Also travelling to the site and communicating with the local people in the village would establish how they have experienced the project.