El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / The Highway Capacity Manual (HCM-2010) indicates in Volume III (Chapter 17) how the characteristics of the environment can represent obstacles that influence the determination of the average pedestrian space. However, the HCM does not specifically analyse in detail how these obstacles affect specifically the path, speed and average walking time of pedestrian. This article performs a comparative analysis between two microsimulations models where it is evidence how by not considering the characteristics of the fixed and mobile environment, the transhipment time and the speed of people are modified. As a case study, the obstacles present in the environment during the transhipment carried out by users in an integrated multimodal transport system in the city of Lima are identified. The comparative analysis between both cases shows the influence of the characteristics of the environment of the transhipment and variation in the average speed of the pedestrians. The proposed study methodology is calibrated and validated by microsimulations in Vissim Software. The comparative analysis reflects an increase in the transhipment time of 19.4% and a decrease in the average speed of the pedestrians by 14.8 %, reflecting in the microsimulation model values near to the real behaviour of pedestrians.

The increased competition and volatile market today have led to the increased interest in agile management control systems. Previous studies have been made on the subject where researchers argue that there is a need for organizations to become agile. However, many practitioners seem hesitant to only implement agile approaches. This study explores how hybrid management control systems are developed and used over time in a large organization. This is a case study that uses semi-structured interviews to collect data. This study found that an agile management control system was not a one-size-fits-all solution. The reason for this is because organizational context and obstacles prevent the organization from fully committing to one management idea. This study concludes that organizations are hesitant to change long-time used practices. Also, managers and employees have different preferences where managers value traditional approaches more while employees prefer agile approaches. Therefore, organizations incorporate parts from various management systems that fit their organization and develop a hybrid management control system.

Syftet med studien är att studera hur lärare introducerar och arbetar med likhetstecknet för att inkludera alla elever och ge dem förutsättningar i sin undervisning. Studiens urval är fyra verksamma lärare som genom semistrukturerade kvalitativa intervjuer belyser sina tankar, erfarenheter och åsikter om hur de arbetar och introducerar likhetstecknet, samt vilka svårigheter som kan uppstå. Resultatet visar att lärarna i studien har ett entydigt arbetssätt men att det finns faktorer som skiljer sig åt. Att det finns faktorer som skiljer sig åt tydliggörs genom att lärarna introducerar likhetstecknet med bland annat konkret material medan introduktionen av likhetstecknet kan se olika ut, lärarna använder olika arbetsmetoder där en lärare väljer att introducera addition och talkamrater innan likhetstecknet, medan en annan lärare uttrycker att likhetstecknet bör introduceras först. Studiens problem är att forskning och myndigheter visar på att elever missuppfattar likhetstecknets betydelse. Den slutsats vi kan dra utifrån syfte, problem och resultat är att lärare behöver anpassa undervisningen för att ge eleverna goda kunskaper för att kunna bemästra matematiken. / The purpose of the study is to observe how teachers introduce and work with an equal sign in order to include all students. This is to give them the prerequisites in their teaching. The study sample involves four active teachers who, through semi-structured qualitative interviews, shed light on their thoughts, experiences, and opinions on how teachers work and introduce the sign of equality as well as what difficulties may arise. The results show that the teachers involved in the study have an unambiguous way of working, however, there are factors that differ. This is shown by the teachers introducing the equals sign with, among other things, concrete material while the introduction of the equals sign can look different. The teachers use different working methods where one teacher chooses to introduce additions and speech mates before the equal sign, while another teacher expresses that the equal sign should be introduced first. The problem with the study is that the research and authorities show that students misunderstand the meaning of the equal sign. The conclusion we can draw based on purpose, problems, and results is that teachers need to adapt the teaching to give students sufficient knowledge to be able to master mathematics.

Philosophiae Doctor - PhD / The purpose of this study was to investigate the epistemological obstacles that mathematics students at undergraduate level encounter in coming to understand the limit concept. The role played by language and symbolism in understanding the limit concept was also investigated. A group of mathematics students at undergraduate level at the National University of Lesotho (NUL) was used as the sample for the study. Empirical data were collected by using interviews and questionnaires. These data were analysed using both the APOS framework and a semiotic perspective. Within the APOS framework, the pieces of knowledge that have to be constructed in coming to understand the limit concept are actions, processes and objects. Actions are interiorised into processes and processes are encapsulated into objects. The conceptual structure is called a schema. In investigating the idea of limit within the context of a function some main epistemological obstacles that were encountered when actions were interiorised into processes are over-generalising and taking the limit value as the function value. For example, in finding the limit value L for./{x) as x tends to 0, 46 subjects out of 251 subjects said that they would calculate ./{O) as the limit value. This method is Within the context of a sequence everyday language acted as an epistemological obstacle in interiorising actions into processes. For example, in finding lim (_1)n ,the majority of x~oo n the subjects obtained the correct answer O. It was however revealed that such an answer was obtained by using an inappropriate method. The subjects substituted one big value for n in the formula. The result obtained was the number close to O. Then 0 was taken as the limit value because the subjects interpreted the word 'approaches' as meaning 'nearer to'. Other subjects rounded off the result. In everyday life when one object approaches another, we might say that they are nearer to each other. It seems that in this case the appropriate for calculating the limit values for continuous functions. However, in this case, the method is generalised to all the functions. When these subjects encounter situations in which the functional value is equal to the limit value, they take the two to be the same. However, the two are different entities conceptually. Within the context of a sequence everyday language acted as an epistemological obstacle in interiorising actions into processes. For example, in finding lim (_1)n ,the majority of x~oo n the subjects obtained the correct answer O. It was however revealed that such an answer was obtained by using an inappropriate method. The subjects substituted one big value for n in the formula. The result obtained was the number close to O. Then 0 was taken as the limit value because the subjects interpreted the word 'approaches' as meaning 'nearer to'. Other subjects rounded off the result. In everyday life when one object approaches another, we might say that they are nearer to each other. It seems that in this case the subjects used this meaning to get 0 as the limit value. We also round off numbers to the nearest unit, tenth, etc. The limit value is however a unique value that is found by using the limiting process of 'tending to' or 'approaching' which requires infinite values to be considered. Some are computed and others are contemplated. In constructing the coordinated process schema, f(x) ~ L as x ~ a, over-generalisation and everyday language were still epistemological obstacles. Subjects still perceived the limit value to exist where the function is defined. The limit was also taken as a bound, lower or upper bound. In a case where the function was represented in a tabular form, the first and the seemingly last functional value that appeared in the table of values were chosen as the limit values. Limit values were also approximated. In constructing the coordinated process an ~ L as n ~ 00, representation, generalisation and everyday language also acted as epistemological obstacles. An alternating sequence was perceived as not one but two sequences. Since the subjects will have met situations where convergence means meeting at a point, as in the case of rays of light, a sequence was said to converge to a number that did not change in the given decimal digits. For example, the limit of the sequence {3.1, 3.14, 3.141, 3.1415, ... } was taken to be 3 or 3.1 as these are the digits that are the same in all the terms. In encapsulating processes into objects, everyday language also acted as an epistemological obstacle. When subjects were asked what they understood the limit to be, they said that the limit is a boundary, an endpoint, an interval, or a restriction. Though these interpretations are correct they are however, inappropriate if used in the technical context such as the mathematical context. While some subjects referred to the limit as a noun to show that they refer to it as an object, other subjects described the limit in terms of the processes that give rise to it. That is, it was described in terms of either the domain process or the range process. This is an indication that full encapsulation of processes into objects was not achieved by the subjects. The role of language and symbolism has been identified in making different connections in building the concept of limit as: representation of mathematical objects, translation between modes of representation, communication of mathematical ideas, manipulation of surface or syntactic structures and the overcoming of epistemological obstacles. In representation some subjects were aware of what idea some symbolism signified while other subjects were not. For example, in the context of limit of a sequence, most subjects took the symbolism that represented an alternating sequence, an = (-lr, to represent two sequences. The first sequence was seen as {I, I, 1, 1,... } and the second as {-I, -1, - 1, -1, ... }.This occurred in all modes of representation. In translating from one mode of representation to another, the obscurity of the symbol lim/ex) = L was problematic to the students. This symbol could not be related to its X~a equivalent form lex) ~ L as x ~ a. The equal sign, '=', joining the part lex) and L does not reflect the process ofj{x) tending to L, rather it appears as if it is the functional value that is equal to L. Hence, instead of looking for the value that is approached the subjects chose one of the given functional values. The part of the symbol lim was a x~a source of difficulty in translating the algebraic form to the verbal or descriptive. The subjects saw this part to mean "the limit of x tends to a" rather than seeing the whole symbolism as the limit of j{x) as x tends to a. Some subjects actually wrote some formulae in the place of L because of this structure, e.g., lim/ex) = 2x. These subjects x~a seemed to have concentrated on the part lex) = .... This is probably because they are used to situations where this symbolism is used in representing functions algebraically. In communicating mathematical ideas the same word carried different meanings for the researcher and for the subjects in some cases. For example, when the subjects were asked what it means to say a sequence diverges, one of the interpretations given was that divergence means tending to infinity. So, over-generalisation here acted as an epistemological obstacle. Though a sequence that tends to infinity diverges, this is not the only case of divergence that exists and therefore cannot be generalised in that way. The manipulation of the surface structures was done instrumentally by some subjects. For 1 . ti di 1·.J x 2 examp e, m in mg im +29 - 3 ,urdmugri the mam.pu 1ati.on some subjiects 0 bttaaime d x.... o x 2 part of the expressions such as ~ by rationalising or .:;- by using L'Hospital's rule 2x x which needed to be simplified. Instead of simplifying the expressions further at this stage, the substitution of 0 was done. So, .o2. = 0 was obtained as the answer. This shows that neither the reasons for performing the manipulations, nor the process of rationalising for example was understood. The result was still an indeterminate form of limit. The numerator was also not yet in a rational form. In using language to overcome epistemological obstacles, subjects were exposed to a piece of knowledge that falsified the knowledge they had so that they could rethink replacing the old with the new. In some cases, this was successful but in others, the subjects did not surrender these old pieces of knowledge. For example, when asked what they understood the 'rate of change' to mean, the majority of the subjects associated the rate of change with time only. However, when referred to a situation that required them to find the rate of change of an area with respect to radius, some subjects changed their minds but others did not. Those who did not change their minds probably did not make any connections between ideas under discussion. The implications for practice of the findings include: In teaching one should discuss explicitly how answers to tasks concerning limits are obtained. The idea of the limit value as a unique value can only be recognized if the process by which it is obtained is discussed. It should not be taken for granted that students who respond correctly understand the answers. It is evident from the study that even when correct answers are given, improper methods may have been used. Hence, in investigating epistemological obstacles attention should also be paid to correct answers. Also beyond this, students should be exposed to different kinds of representation of the limit concept using simple functions and using a variety of examples of sequences. Words with dual or multiple meaning should also be discussed in mathematics classrooms so that students may be aware of the meanings they carry in the mathematical context. Different forms of indeterminate states of limit should be given attention. Relations should also be made between the surface structures and the deeper structures.

Prison management and key stakeholders lack an understanding of how institutional obstacles interfere with probation officers and parole agents' ability in managing offenders to reduce recidivism in a Midwestern state. In 2014, 1 out of 52 adults in the U.S. were under the supervision of probation officers or parole agents. The purpose of this descriptive phenomenological study was to identify the institutional obstacles that exist for probation officers and parole agents in terms of their lived experiences in their jobs. The participants were 5 probation officers and 6 parole agents from a municipal district in a county in a Midwestern state. The conceptual framework that grounds this descriptive phenomenological study is Meadows' three concepts of systems thinking (elements, interconnections, and purpose). The data collection process involved in-depth interviews and field notes. One hundred percent of the participants identified several themes as institutional obstacles including: lack of community programs, lack of jobs, and heavy caseloads. The implications for positive social change for the key stakeholders identified in the study to reduce recidivism in the criminal justice system were to remove the institutional barriers outlined in the themes and improve institutional practices. Making policy reforms that included drug and alcohol treatment, addressing the issue of prison authority and the creation of rehabilitation programs that feature cognitive development would aid in reduction of recidivism.

Purpose: This study aims to identify obstacles and challenges that prevent the reuse of building materials and bring forth possible solutions. But also to examine the technical-, economic- and environmental advantages and disadvantages of using reused building materials. Method: The study is based on literatures that have been sustained from scientific articles, interviews and analyses of reference objects. The main study mainly consists of information gathered from scientific articles that have been analysed in a literature study. Information was also gathered from nine interviews that have been done with various professionals that works in the construction industry. Results: Several obstacles that arise when reusing building materials were identified. One of the major barriers is logistics and storage of recycled materials. Furthermore, legal and official requirements, the demolition process, guarantees, quality of the material and insufficient knowledge of those who work or want to work with recycling and material reuse. Based on the reference objects, the survey shows large environmental savings in both reduced carbon footprint and reduction of large amounts of demolition waste. Based on the literature analysis, proposals for solutions have been develop to all the obstacles and risks that have arisen. Conclusions: Finally, there are several obstacles that make it difficult to reuse in the amount that actors desire. Over time, recycling will increasingly become more common, and solutions will come along with it. But more research and more pilot projects will develop knowledge in recycling and facilitate development in general. New legislation promoting or forcing recycling projects will also be needed.

En av de största utmaningarna för Östersjöregionen gäller bekämpningen av övergödning orsakad av människors utsläpp av näringsämnen till havet. Övergödningen har flera allvarliga konsekvenser för miljön, inte minst enorma algblomningar samt stora mängder alger och tång som så småningom spolas upp längs Östersjöns stränder och börjar förmultna. På gotländska kallas dessa organiska massor på stränderna för “släke” och ses oftast som ett problem då de kan försämra kustmiljön och störa turister och lokalbor som vill bada eller vistas på stranden. Släken är dock rik på näring, och att skörda släken för att använda den som en resurs skulle kunna bidra till att skapa cirkulära flöden då näring återtas från havet, samtidigt som stranden rensas och släken kan bli en potentiellt värdefull resurs som exempelvis jordförbättringsmedel eller biobränsle. Det finns dock flera hinder i vägen för att få till en hållbar skörd och användning av släke.  Projektets syfte är att undersöka vilka möjligheter som finns för att på ett hållbart sätt skörda och använda släke som en bioresurs på Gotland. Detta gjordes dels genom att identifiera hinder och incitament för släkeskörd med hjälp av en litteraturstudie över släkeskörd i Östersjöområdet samt genom en intervju med en person som arbetar med släkehanteringsfrågan i Gotlands länsstyrelse. Det undersöktes även genom en fallstudie där hinder identifierades och utvärderades för att uppskatta möjligheterna för släkeskörd inom ett valt studieområde på Gotlands östkust.  Ett flertal hinder för skörd och användning av släke kunde identifieras i litteraturstudien, som sedan delades in i de följande huvudsakliga kategorierna: skräp, erosion, biologisk mångfald, maskiner, kostnader, juridiska hinder, tidspress, kvalitet, logistik samt tungmetaller. Resultat från intervjun styrker att flera av dessa hinder är aktuella på Gotland, däribland biologisk mångfald som kan riskera att ta skada vid skörd och avlägsnande av släke, olika juridiska hinder för att få bidrag för att skörda släke, och det potentiella innehållet av tungmetaller i släke som kan begränsa dess användning, bland annat. I fallstudien framkom det att några av de viktigaste hindrena är juridiska hinder i form av olika naturskydd, som exempelvis naturreservat, som begränsar eller på andra sätt påverkar möjligheten att skörda släke. Risk för erosion genom bortförande av sand samt kostnader i samband med skörd med maskiner är ytterligare faktorer som påverkar lämpligheten för släkeskörd. Även inblandning av antropogent skräp i släken togs upp.  En slutsats som kan dras är att det finns många fördelar men även många hinder kring skörd och användning av släke. För att kunna avgöra huruvida det är möjligt att skörda och använda släke på ett hållbart sätt behöver skördeområdet först analyseras utifrån dessa hinder och sedan vägas mot fördelarna. Fallstudien visade att stränderna i studieområdet hade olika förutsättningar för hållbar släkeskörd utifrån de studerade hindrena. Flera hinder kunde dock inte appliceras på studieområdet på grund av bristande data, och det går därför inte att dra någon fullvärdig slutsats om hållbar släkeskörd i studieområdet. / One of the biggest challenges for the Baltic Sea region concerns the mitigation of eutrophication induced by nutrient emissions caused by humans. Eutrophication has numerous severe impacts on the environment, such as massive macroalgal blooms that contribute to the presence of large amounts of algae and seaweed that are eventually washed ashore on the Baltic Sea coast where they begin decomposing. On Gotland, these organic masses are called “släke”, beach wrack or beach cast in English, and are usually considered a nuisance as they can bother beach tourists. Beach cast is however very rich in nutrients, and harvesting beach cast to use it as a resource could contribute to creating circular flows as nutrients are removed from the sea while simultaneously the beach is cleaned and the beach cast could pose a potentially valuable resource useful for soil improvement or biofuel, for example. There are, however, several obstacles in the way of sustainably harvesting and using beach cast. The purpose of this project is to investigate the available possibilities to sustainably harvest and use beach cast as a bioresource on Gotland. This was done partly by identifying obstacles and incentives for beach cast harvesting in the Baltic region using a literature study as well as an interview with a government figure on Gotland. It was also explored through a case study where these obstacles were used to estimate the possibility of harvesting beach cast in a chosen study area on the east coast of Gotland. Several obstacles for harvest and use of beach cast could be identified in the literature study and were then divided into the following main categories: trash, erosion, biodiversity, machines, costs, juridical obstacles, time constraint, quality, logistics and heavy metals. Results from the interview corroborate that many of these obstacles are present on Gotland, among others, biodiversity that is susceptible to damage caused by harvesting or the removal of beach cast, various juridical obstacles to attain funding, and the potential contents of heavy metals in beach cast that can limit its possible uses. The case study also showed that some of the most important obstacles are juridical obstacles such as different forms of environmental protection such as nature reserves, that limit the possibility to harvest beach cast. The risk of erosion through removal of sand and costs due to harvesting with machines are other factors that affect the suitability of harvesting beach cast. Also, anthropogenic trash mixed in with the beach cast was mentioned. A conclusion that can be drawn is that there are many advantages as well as obstacles when it comes to harvest and use of beach cast. To be able to harvest and use beach cast in a sustainable manner the harvest site needs to be analyzed using these obstacles and be weighed against the advantages in order to determine whether harvesting is suitable. The case study also showed that different beaches have different qualifications for sustainable beach cast harvesting based on the obstacles. Several of the obstacles found in literature or from the interview couldn’t be applied to the study area, however, due to limited data, and therefore it is not possible to draw any exclusive conclusions concerning sustainable beach cast harvesting in the area.

Background: Twenty percent of Americans live in rural areas where most of their healthcare is provided in Critical Access Hospitals (CAHs). It is unknown how frequently obstacle and helpful behavior items occur in End-of-Life (EOL) care in CAHs. Objectives: To determine the frequency of occurrence scores of obstacle and helpful behavior items in providing EOL care in CAHs. To also determine which obstacles and helpful behaviors have the greatest or least impact on EOL care based on the magnitude scores. Methods: A questionnaire was sent to nurses working in 39 CAHs in the United States. Nurse participants were asked to rate obstacle and helpful behavior items by size and frequency of occurrence. Data were analyzed to quantify the impact of obstacle and helpful behavior items on EOL care in CAHs by multiplying the mean size by the mean frequency of items to determine mean magnitude scores. Results: Items with the highest and lowest frequency were determined. Additionally, obstacle and helpful behavior item magnitude scores were calculated. Seven of the top ten obstacles were related to patients' families. Seven of the top ten helpful behaviors involved nurses ensuring families had positive experiences. Discussion: CAH nurses perceived issues around patient family members as significant obstacles to EOL care. Nurses work to ensure that families have positive experiences. Visiting hour issues seemed to be irrelevant. The use of technology, such as telehealth, seemed to provide little benefit in EOL care in CAHs.

With radical social change and educational reform taking place in China since 1976, the English teaching system there has been changing accordingly. The Chinese Traditional Method (CTM) is giving way to the Western Communicative Language Teaching (CLT) approach. This research is a study of both Chinese and expatriate English teachers who are involved in classrooms and affected by reforms. The goal of this research study is to identify the extent to which Chinese and expatriate English teachers use CLT in China, to discover the possible factors that prevent them from using CLT and to explore an English teaching method that may fit into the Chinese setting. The finding shows that both Chinese teachers and Americans used the CLT approach in their teaching. As for the extent to which they use CLT, overall variation between the two groups is not as obvious as variation within groups. Both Chinese and American teachers have encountered obstacles in introducing CLT. Recommendations were offered for teachers, students, and administrators.

The ambition for a more digitalized and effective line of business is large for building companies. It is of great importance, to the companies in the building sector, that the adaption of new tools and methods of working happen to secure their place in a modern and competitive line of business. BIM-building process is the tool the companies need to reach their ambitions.  One of Veidekke´s goals is to use BIM throughout the entirety of their projects. This work has with cooperation with Veidekke Sverige clarified what obstacles there are for the implementation of BIM in the building production an also to give propositions for actions to fix these obstacles. The study has mainly been done through half controlled interviews with key individuals and thru available literature studies.  The result of the study has shown that there are three main obstacles that have slowed the implementation of BIM in the building process. These obstacles are as follows: the level of detail of the BIM model, technical difficulties associated with software and hardware, and the human aspect.  The solutions to these obstacles have been brought forward regarding the position of Veidekke Sverige, in the line of business of building, regarding BIM, and are made up of our own speculations from past experiences and knowledge gathered though the course of the education.