151 |
Relação entre preço e custo marginal na indústria brasileira / Price and marginal cost relation in brazilian industryMeyer, Leandro Garcia 16 May 2012 (has links)
A relação entre preço e custo marginal pode ser utilizada para evidenciar características das indústrias, com destaque para aspectos relacionados à concorrência. Uma das formas de estimar esta relação, definida como mark up, é a análise da relação entre insumos e produtos. Na presente pesquisa, este tipo de estudo foi realizado por meio da análise do resíduo de Solow, como em Hall (1986), e a partir da estimação da função de produção, conforme proposto por Loecker e Warzynski (2009). As características complementares dos procedimentos e o fato de haver insuficiente análise de aspectos concorrenciais das indústrias nacionais favorecem o emprego conjunto destas abordagens para o caso da indústria brasileira, sendo este o objetivo da presente pesquisa. Foram utilizados dados da PIA-Empresa (IBGE) para as indústrias de extração e transformação entre 1996 e 2007. A análise do resíduo de Solow evidenciou que a hipótese conjunta de retornos constantes de escala e concorrência perfeita para a indústria nacional não é válida, com altas estimativas de mark up para os setores extrativista, alimentício, florestal e químico. Já os setores têxtil e máquinas e equipamentos apresentaram baixas estimativas. As estimativas obtidas por meio da função de produção e a análise dos retornos de escala confirmaram os altos mark ups dos setores florestal e químico. Para os setores extrativista e alimentício as estimativas foram consideravelmente menores, o que foi interpretado como consequência do retorno de escala dos setores, que deve ser decrescente. Não houve diferença estatisticamente significativaentre as estimativas obtidas para os setores metalurgia básica, eletro eletrônico, têxtil e máquinas e equipamentos por meio das duas metodologias, o que corrobora as evidências encontradas sobre retornos de escala, que indicaram que estes são constantes para tais setores. Para os demais setores não foi possível obter constatações relevantes sobre as estimativas alternativas e retornos de escala. Dessa forma, foram encontradas evidêcias de que a hipótese de concorrência perfeita não é válida, com mark ups maiores do que dois para quase todos setores. / The price and marginal cost relation can evidence important industry features, especially the ones that concern competition. Input and output data can be used to estimate the price and marginal cost relation, defined as mark up. In this research, this type of study was done by the Solow residual analysis, as in Hall (1986), and by the production function estimation, as in Loecker e Warzynski (2009). The returns to scale influences both methodologies, and was used to compare their results. The methodologies complementaries features and the fact that there is few analisys about competition in brazilian industry stimulates the use of the Solow residual and the production function to calculate the mark up of the brazilian industry. The data of the extraction and transformation industries used in this research are from PIA-Empresa (IBGE) for the years between 1996 and 2007. The 104 industries were classified in eleven sectors: extrative, food, forest, textile, chemistry, non-metallic mineral, metallurgy, machines and equipment, electronics, general equipment and automotive vehicles. The Solow residual analysis rejected the competition and constants returns to scale hypothesis, and the extractive, food, forest and chemistry sectors showed high mark ups. Textile and machines and equipment had low mark ups. The mark up estimatives from the production function estimation and the returns to scale analysis confirmed the high mark ups for the forest and chemistry sectors. For the extractive and food sectors the mark ups were lower, what is probably consequence of the decreasing returns to scale that these sectors may have. There were no statistically significant di_erence between the mark ups estimatives obtained from both methodologies for the metallurgy, electronics, textile and machines and equipment sectors, what support the evidences of constant returns to scale that were found. The other sectors did not showed relevant conclusions about the relations between the estimatives and the returns to scale. Hence, the perfect concorrence hypotesys is not valid for the brazilian industry.
|
152 |
Degradation of a Polymer Electrolyte Membrane Fuel Cell Under Freeze Start-up OperationRea, Christopher January 2011 (has links)
The polymer electrolyte membrane fuel cell (PEMFC) is an electrochemical device used for the production of power, which is a key for the transition towards green and renewable power delivery devices for mobile, stationary and back-up power applications. PEMFCs consume hydrogen and oxygen to produce power, water and heat. The transient start-up from sub-zero freezing temperature conditions is a problem for the successful, undamaged and unhindered operation. The generation and presence of water in the PEMFC stack in such an environment leads to the formation of ice that hinders the flow of gases, causes morphological changes in the membrane electrode assembly (MEA) leading to reversible and irreversible degradation of stack performance.
Start-up performance is highly dependent on start-up operational conditions and procedures. The previous state of the stack will influence the ability to perform upon the next start-up and operation. Water generated during normal operation is vital and improves performance when properly managed. Liquid water present at shut-down can form ice and cause unwanted start-up effects. This phase change may cause damage to the MEA and gas diffusion media due to volume expansion. Removal of high water content at shutdown decreases proton conductivity which can delay start-up times. The United States Department of Energy (DOE) has established a set of criteria that will make fuel cell technology viable when attained. As specified by DOE, an 80 kWe fuel cell will be required by 2015 to reach 50% power in 30 seconds from start-up at an ambient temperature of -20°C.
This work investigates freeze start-up in a multi-kilowatt stack approaching both shut-down conditioning and start-up operations to improve performance, moderate fuel cell damage and determine the limits of current stack technology. The investigation involved a Hydrogenics Corporation 5 kW 506 series fuel cell stack. The investigation is completed through conditioning the fuel cell start-up performance at various temperatures ranging from -5°C to below -20°C. The control of system start-up temperature is achieved with an environmental chamber that maintains the desired set point during dwell time and start-up. The supply gases for the experiment are conditioned at ambient stack temperature to create a realistic environment that could be experienced in colder weather climates. Temperature controls aim to maintain steady ambient temperatures during progressive start-up in order to best simulate ambient conditions. The control and operation of the fuel cell is maintained by the use of a fuel cell automated test station (FCATS™). FCATS supplies gas feeds, coolant medium and can control temperature and reactant humidity in reactants according to a prescribed procedure for continuous operation. The
iv
collection of data occurs by the same system recording cell voltage, temperatures, pressures, flow rates and current densities. A procedural start-up and characterization are conducted in order improve start-of performance and examine reactant flows, coolant activation time, stack conditioning and the effects by freezing temperatures. The resulting degradation is investigated by polarization curves and various ex-situ measurements. In this work, it was found that freeze start-up of a fuel cell stack can be aided and managed by conditioning the stack at shut-down and applying a procedure to successfully start-up and mitigate the damage that freezing can cause.
|
153 |
The impact of warm up intensity and duration on sprint performanceWatterdal, Øyvind January 2013 (has links)
A traditional warm-up (WU) for track sprinters usually includes a general WU, a series of mobility drills and some short sprint strides lasting 30-60 min in total. A WU of this duration might cause significant fatigue and impair sprint performance. Aim: To test the hypothesis that a traditional high intense warm-up of long duration would elicit fatigue and impair sprint performance. Methods: Five highly trained males competitive in endurance sports performed three different WU protocols on separate days in their postseason period. Their mean ± SD age, body mass and height were 24.2 ± 1.6 years, 78.4 ± 7.8 kg, 179.6 ± 8.8 cm. The study participants performed a timed 60 meter sprint on an indoor track. The traditional warm-up (LONG), started with 10 min of easy running; then 7 min of mobility drills followed by five sprints performed with 3-min break in between. The total duration of LONG was 35 minutes. The experimental warm-up (SHORT) was shorter and less intense; 10 min of easy running was followed by just one sprint. Both warm-up protocols were followed by 10 min of recovery, where participants were not allowed to sit down. A third test occasion served as control (CON), where participants did not conduct physical activity prior to the time trial, only 10 min of recovery. Participants also rated the satisfaction of their performance on a 10 point scale. Results: The results of 60 m time trial performance showed no significant differences among the different WU protocols (P = 0.20). The 60 m performance was better for SHORT (8.02 ± 0.10 sec) than for LONG (8.08 ± 0.16 sec) and CON (8.20 ± 0.21 sec). 4 of 5 participants experienced their fastest time trial following SHORT. It appeared that participants were significantly faster following SHORT (7.99 ± 0.22 ms-1) compared to LONG (7.77 ± 0.33 ms-1) in the final 10 m of the time trial (P = 0.05). The satisfaction after SHORT scored highest (6.9), followed by LONG (5.9) and CON (4.5). Conclusions: There is no significant difference between a traditional WU compared to a WU of shorter duration and lower intensity. The traditional WU showed a significant decline in running speed in the final stage of the time trial, which might be caused by fatigue.
|
154 |
Concurrent Engineering Approaches within Product Development Processes for Managing Production Start-up phaseEbrahimi M., Sajjad January 2011 (has links)
Nowadays in a turbulent market, developing and launching a new product is one of most competitive strategies implemented by many large and small enterprises. In fact, launching a new product depends upon the performance of four critical functions: design, manufacturing, distribution and marketing. Their performances would increase or decrease the total time-to-market and consequently time-to-money. Time-to-market would be improved if the manufacturing system can diminish time-to-volume/quality/cost during production start-up phase. In order to overcome the impediment during a start-up phase, the significant parameters which are influencing a production start-up phase should be identified and managed. Hence, a system-wide approach would facilitate a product realization process so as to achieve global optimization throughout the entire process. One of such systems is Concurrent Engineering which can be applied owing to being enable to choose the best practice to improve product introduction process, being capable to improve cross functional integration and communication, and being empowered to apply a set of comprehensive methods for design analysis so that designers can select the most optimal design solution which is not only considering the design constraints, but also taking the constraints of production system, logistics and distribution into account. Hence, it can cover majority of problems in start-up phase which are generated due to lack of empathy between design and manufacturing. This research studied the significant parameters influencing a production start-up phase. Then, it investigated whether the principle of concurrent engineering would support an efficient start-up phase. The selected research methodology is based on a conceptual and supportive literature review of the current scholars. The research design is according to a three-step process which is applied to catch most relevant literatures. The research implements an analogy reasoning logic to establish the outcome of the research through the comparison between principles of a concurrent engineering program and significant parameters. As a result of the research, the significant parameters are identified, in addition, a managerial framework is structured that can present the requirements to manage an efficient start-up phase. Moreover, the results indicate how a concurrent engineering program would support a start-up phase.
|
155 |
Once you pop your customer will shop : - A study about pop-up storesBergqvist, Anna, Leinoff, Louise January 2011 (has links)
Background: E-commerce retailing is the most rapidly growing shopping mode and has quickly gained a huge market share. The increased growth rate means that the competition among online based companies is growing. Therefore the challenge faced is how to be unique on an extremely competitive market and being able to reach customers in a jungle of information and communication. By identifying barriers and weaknesses in the existing online sales mode, new complementary tools might be found which can help online based companies to stay competitive, meet customers’ demands and deliver exclusive experiences. Purpose: The purpose of this thesis is to describe the new phenomenon pop-up store and investigate if it could be a complementary tool for online based companies to help tackling limitations inherent in e-businesses. Methodology: In this study we conducted seven interviews with people that have been working with pop-up store concepts in some way. Two of the interviewees were consultants, one was a specialist on pop-up stores and the rest were Marketing Managers of well known Swedish companies. Conclusions: This study showed that the three most prominent limitations inherent with e-business (lack of human interaction, communication, capture of visitors’ attention) could be overcome with a pop-up store. Proposals for future research: It would be interesting to further investigate, in connection to this study, how customers have perceived the concepts and if they think that a pop-up store could increase their knowledge about an online based company and enhance their willingness to purchase through the web
|
156 |
Nostalgia in George Orwell's Coming Up For AirNourmohammadi, Shima January 2011 (has links)
Modernity has changed the world and subsequently has caused emotional wounds and a sense of nostalgia for those pleasant times and places left in the past. In fact, nostalgia and modernity were two principle notions that people face in the early 20th century. This study calls on the notion of nostalgia defined by J. Wilson, which suggests that hard life situations and modernity enforcing unwanted changes in life, bring a feeling for the past like missing something left behind. Taking Wilson’s definition as a point of departure, this study analyses the protagonist's nostalgic feeling and nostalgia in the novel Coming Up For Air written by George Orwell. It also compares Coming Up For Air with two other Orwell’s writings which demonstrate that a grief for legacy of the past is recurrent in his writings. In addition, this study argues that nostalgia is not only a sentimental motion or mourning for the lost past but it also creates a pleasant space for the protagonist to recover from hardships caused by the modern life in the early 20th century. This study investigates the protagonist’s returning to his childhood town to make his dream of home real. The notion of Place Attachment by Ben Dowler is applied in this study, which demonstrates that the hometown means happiness and a safe place for the protagonist because he was in connection with a sense of happiness and joy in that place. In addition, Abraham Maslow’s theory about human basic needs, which demonstrates that the protagonist looks for a safe place because of his aroused basic need of being secure in the war times, is addressed. Furthermore, this study applies Sigmund Freud’s theory of Mental Structure. The theory is about the three layers of mind from instinct to mature and demonstrates that three different layers of the protagonist’s mind lead him to reply differently to his need of returning home. The main claim of this theory is that although the protagonist has no control over his aroused basic need for security, the mature one makes him more connected to the real world and helps him to cope with his nostalgia.
|
157 |
Synthesis of Metallic Nanowires Using Integrated DNA Molecules as TemplatesErler, Christiane 24 March 2010 (has links) (PDF)
The DNA double helix is inherently a nanoscale wire-like object, possessing a 2 nm diameter as well as a remarkable capability for molecular recognition and the interaction with other chemical compounds, thus making it an attractive material for biologically driven assembly of artificial nanostructures. In this work methods for the construction of functional electronic networks from single DNA molecules are presented. For this, (i) the generation of patterns of distinct interconnects between micro-fabricated contact pads are explored by stretching end-specifically thiol-functionalized, single-tethered DNA molecules using hydrodynamic flow as well as an electric field-induced thermal flow. (ii) These networks then serve as a template for a selective in-situ photoinduced nucleation and growth of platinum clusters of 4 nm diameter along the DNA molecules. In the synthesis exclusively platinum ions from an aqueous platinum nitrate solution bonded electrostatically to the backbone of the immobilized DNA can be reduced upon irradiation with UV light, while background metallization is inhibited. Furthermore, the metallization scheme is applied to DNA nanotubes and another photochemical deposition process is used to tune the interparticle gap space in a discontinuous platinum cluster chain to form conducting nanowires.
The "process toolbox'' presented in this work offers a versatile alternative for the hierarchical patterning and incorporation of biotemplated nanomaterials into micro-/nanofabrication schemes. / Ein doppelhelikaler DNA-Strang besitzt mit seinem hohen Aspektverhältnis von Natur aus Ähnlichkeit mit einem Kabel. Zusammen mit seinen einzigartigen Selbstassemblierungseigenschaften sowie der Fähigkeit, mit einer Vielzahl von chemischen Stoffen eine Verbindung einzugehen, macht dies ihn zu einem aussichtsreichen Baumaterial für den Aufbau von künstlichen Nanostrukturen. In dieser Arbeit werden deshalb verschiedene Methoden für den Bau von elektronischen Schaltkreisen aus einzelnen DNA-Strängen demonstriert. Dazu wird (i) die Herstellung von Verdrahtungsmustern zwischen lithographisch gefertigten Kontaktstrukturen untersucht. Endständig mit Thiolgruppen funktionalisierte DNA-Moleküle, die an nur einem Ende mit der Oberfläche verknüpft sind, werden mittels Strömung oder eines elektrothermisch induzierten Flusses zwischen Elektroden gespannt. (ii) Diese Netzwerke dienen im Weiteren als Vorlage für ein selektives, lichtinduziertes Wachstum von Platinpartikeln mit Durchmessern von 4 nm lokal entlang der DNA-Moleküle. Dabei werden unter UV-Bestrahlung nur solche Platinionen reduziert, die aus einer Platinnitrat-Lösung elektrostatisch an die immobilisierte DNA angebunden haben. Partikelwachstum in der umgebenden Lösung wird weitgehend verhindert. Darüber hinaus wird dieses Verfahren auch auf DNA-Nanoröhren angewendet und ein weiterer photochemischer Abscheideprozess eingesetzt, um unterbrochene Clusterkettern zusammenzuwachsen, mit dem Ziel, elektrisch leitfähige Nanodrähte zu erhalten.
Die vorgestellten Verfahren stellen eine vielseitige Alternative zu herkömmlichen, hierarchischen Fabrikationsschemen der Mikro- und Nanotechnologie dar.
|
158 |
Ärendehantering i DHL expressKjellberg, Martin January 2005 (has links)
<p>Syftet med denna rapport är att analysera DHL express behov av ärendehantering. Unified process och unified modelling language har använts för att kartlägga vilka nyckelfunktioner som skulle kunna ingå och vilka krav som DHL har på ärendehantering. Utifrån resultatet av unified process har en prototyp byggts upp för att demonstrera hur ärendehanteringen ser ut praktiskt</p> / <p>The purpose of this report is to analyse DHL Express need for information management in Växjö. Unified process and Unified modelling language have been used to capture the requirements and to make an analysis in order to map key functions for an information management system. From the result of the Unified process a prototype has been built to demonstrate practically the functions in an information management system.</p>
|
159 |
Morgondagens detaljhandel : En studie om pop-up butiker, showrooms samt omnikanalers betydelse i detaljhandels framtid / Tomorrow's retail : A study about pop-up stores, showrooms and omnichannels importance in the future of retail.Löfberg, Thérèse, Sturesson, Petra January 2015 (has links)
Forskningsfrågor Hur kommer företag att arbeta med showrooms och pop-up butiker i framtiden? Hur ska företag integrera sina olika försäljningskanaler för att behålla en stark position på marknaden? Syfte Syftet med uppsatsen är att undersöka hur detaljhandeln kommer att utvecklas i framtiden genom användandet av nya kreativa försäljningskanaler, för att nå nya samt redan befintliga kunder. Vidare syftar uppsatsen till att undersöka vikten av att företagens olika försäljningskanaler är integrerade för att kunna möta kundernas efterfrågan. Syftet är även att skapa en förståelse utifrån hur företag, genom sin kanalintegration, kommer att få konkurrensfördelar på marknaden. Metod Uppsatsen är skriven med en kvalitativ forskningsmetod som har en induktiv ansats med deduktiva inslag. Vi har under studien insamlat empirisk data genom semistrukturerade intervjuer samt två fokusgrupper. Slutsats I denna studie kommer vi fram till att pop-up butiker är ett fenomen som kommer bli allt vanligare, då det är en försäljningskanal som har många fördelar. Studien visar även att showrooms, mot slutkunder, kommer bli allt vanligare. Integrationen av ett företags försäljningskanaler kommer samtidigt bli viktig, för att skapa helhetsupplevelsen för kunder. / Research question How will companies work with showrooms and pop-up stores in the future? How can companies integrate their various sales channels to maintain a strong position in the market? Purpose The purpose of this thesis is to investigate how the retail industry will evolve in the future- using novel creative sales channels to reach both new and existing customers. Furthermore, the thesis aims to examine the importance of how corporations’ different sales channels are integrated in order to meet customer demand. Another objective is to gain an understanding of how companies, through channel integration, can attain a competitive advantage in the market. Method We used a qualitative research method with an inductive approach but incorporating some deductive elements in order to investigate the above questions. During the study we collected empirical data through semi-structured interviews and from two focus groups. Conclusion Our research suggests that the pop-up store is a phenomenon that will continue to grow because it has many advantages as a sales channel. Moreover, it indicates that showrooms will broaden their target market to include end consumers. The integration of a company's sales channels will also be important to create a cohesive overall experience for customers.
|
160 |
Uppvärmningens betydelse för hopphöjd och fem sekunders sprintprestation : En experimentell studie om hur anaerob prestation påverkas av uppvärmningsintensitetNorén, Petter January 2013 (has links)
Syfte och frågeställningar Studien genomfördes med syftet att specificera vilken intensitet och duration vid uppvärmning som är optimal för att få ut största möjliga effekt vid anaerob prestation i form av maximalt vertikalhopp och fem sekunders maximal cykelsprint. Studien byggde på tre frågeställningar: På vilket sätt påverkar uppvärmningen prestationen vid ett maximalt vertikalhopp? På vilket sätt påverkar uppvärmningen prestationen vid ett maximalt fem sekunders sprinttest? Vilken uppvärmning är optimal för maximal muskulär explosivitet? Metod Designen var en kvantitativ experimentell studie som innefattade fyra fysiskt aktiva kvinnor med genomsnittsålder på 24 år. Testerna bestod av nio tillfällen där en slumpad uppvärmning på ergometercykel genomfördes varje gång. Därefter genomfördes tre vertikalhopp, så kallade counter movement jump, på en kraftplatta och tre fem-sekunders sprint (5sCST) på Monarks Peak Bike. Hopphöjd, mean power, peak power och kroppstemperatur mättes vid varje testtillfälle. Resultat Resultaten visade att maximal muskulär explosivitet vid vertikalhopp uppnåddes efter uppvärmning i fem minuter på 150w vilket motsvarade en belastning på 53 till 76 procent av VO2max för testpersonerna. För maximal muskulär explosivitet vid 5sCST påvisades inga signifikanta resultat. Resultatenvisade inte heller några skillnader i kroppstemperatur efter de olika uppvärmningsintensiteterna. Slutsats För de fyra kvinnorna var det optimalt att värma upp i fem minuter med en belastning på 53 till 76 procent av VO2max för maximal hopphöjd vid counter movement jump. Det var endast hopphöjden som påverkades av uppvärmningen och inte någon av de andra parametrarna; mean power, peak power eller kroppstemperatur. Individuella variationer påvisades men vidare studier behövs, med ett större antal försökspersoner och med slumpmässig urvalsgrupp, för att kunna generalisera resultaten.
|
Page generated in 0.0933 seconds