Robust estimation in measurement error models

We consider the simple measurement error regression model y[subscript] t = [beta][subscript]0 + [beta][subscript]1x[subscript] t + q[subscript] t, (Y[subscript] t,X[subscript] t) = (y[subscript] t,x[subscript] t) + (w[subscript] t,u[subscript] t), where [beta] = ([beta][subscript]0, [beta][subscript]1) is the parameter of interest, (Y[subscript] t, X[subscript] t), t = 1, 2, ..., n, are the observations, (y[subscript] t, x[subscript] t) are the true vectors, (w[subscript] t, u[subscript] t) are measurement errors, and q[subscript] t is the equation error. We assume that the measurement errors a[subscript] t = (w[subscript] t, u[subscript] t), t = 1, 2, ..., n, are independent of (q[subscript] j, x[subscript] j) for all t and j and that q[subscript] j is independent of x[subscript] t for all t and j. It is also assumed that the covariance matrix of a[subscript] t is known;Extreme observations have an adverse effect on the usual estimators of the parameters. A class of estimators of [beta] is constructed in which the effect of extreme observations is reduced. Our estimation procedure is based on the robust regression of Y on X and the robust regression of X on Y. The asymptotic joint distribution of the robust estimators of the regression coefficients and error mean squares is obtained when the observations are sampled from a bivariate normal distribution. The robust estimator of [beta] is a smooth function of the estimated regression coefficients and the estimated error mean squares from the two robust regressions. We show that for normal distributions, under certain regularity conditions, our estimator is consistent and normally distributed in the limit. The robust estimation procedure is developed to be robust against a single outlier and then extended to be robust against multiple outliers. A Monte Carlo study is presented to show that our estimator is insensitive to outliers and that the efficiency loss is modest when there is no outlier in the sample

Sustainability in fashion supply chains: Examining the dynamics of small and medium enterprise sustainability in fashion industry multitier supply chains

Sustainability in supply chain management (SSCM) has become established in both academia and increasingly in practice (Fraser, Müller and Schwarzkopf, 2020). As stakeholders continue to require organisations to take more responsibility for their entire supply chains, this has led to the development of multitier SSCM. Despite small and medium enterprises’ (SMEs’) pivotal impact on the global economy, environmental and social responsibility commitments and SSCM have been largely overlooked (Chow et al., 2017). Little attention has been paid to the convergence of sustainability dimensions in SMEs. This thesis examines how sustainability-inspired SMEs in the fashion industry in Scotland implement sustainability and diffuse sustainability across the diverse supply chain. This leads to an investigation of the factors that influence sustainability practices along the supply chain and practices adopted to verify sustainability in the supply chain, with an overall view to improving multidimensional performance. This research adopts an exploratory multiple case study approach that combines multiple data sources: semi-structured interviews, observation, and secondary data analysis. The empirical study includes two SME fashion retailers registered in Scotland and their respective supply chain partners. This thesis contributes to SSCM research in SMEs by exploring from both the conceptual and empirical points of view, investigating fashion SMEs’ sustainability and SSCM and developing a conceptual sustainability performance rating model. This conceptual model uses multidimensional sustainability measurement criteria derived from the literature to determine sustainability performance levels from the farm to the retailer. Evaluation of the supply chain is likely to aid supplier selection, sustainability comparison and transparency. The investigated fashion SMEs and their supply chains are used to exemplify the usefulness of the proposed conceptual sustainability performance model. Based on the supply chains investigated, both retailers’ sustainability performances are similar, while one supply chain outperformed the other. In addition, the research findings show that SME retailers face the greatest challenge in managing supply chain sustainability, while the most influential suppliers can develop creative approaches to diffuse sustainability within the supply chain. This thesis suggests that there is considerable need for further qualitative research and the proposed model perhaps needs to be implemented in various business models to evaluate its validity

Metaforer som interaksjonsstruktur i Multimedia og Hypermedia

This is a Cand. Sicent.(M.Sc) thesis in computer science presented to the Department of Informatics at the University of Oslo. This thesis investigates the process of constructing a presentation, using multimedia and hypermedia information systems, within the particular context of supporting five different types of metaphors; Film, book, encyclopadeia, voyage of discovery and guided tour. The thesis is based on the fact that using metaphors as interaction structure help users to use the program in an easy manner. First there is a simple description of what media, multimedia, hypermedia and interactivity means. Next, I present those five metaphors; what they mean, differences between them, and how they are built. Empirical studies based on the product Slime and the website Startsiden, in this thesis, are examples used in discussing the theoretical structure of metaphors. The discussion is based on what metaphors as interaction structure in multimedia and hypermedia can help users with? And what is the consequence when using one of these metaphors

Different kind of rehabilitation exercises to reduce the number of falls among senior citizens - A literature review

Falls among elderly population is one of the most common problems in the world that leads to majority of elderly hospitalizations and deaths. Aging reduces muscle strength, balance and coordination. Reduced muscle strength, endurance and power will promote to a deduction of physical functions below the limit. Because of that, activities of daily living (ADL) may become more challenging and impossible. Aim of this literature review research was to determine which type of exercises (balance, coordination and strengthening) has been proven most successful to reduce the number of falls among seniors. Method used for this thesis was literature review which follows the main principles of systematic search. A systematic search was conducted in PubMed, EBSCOhost and Cochrane. 7 Randomized Controlled Trials (RCT) articles were selected for the thesis which fulfilled the inclusion criteria. According to the results, majority of elders shows falls and injuries related to falls. Results show that exercise sessions of strength training, balance training and coordination exercises create major difference concerning the reduction number of falls among elderly population. Also, practising the following exercises shows significant reduction in falls: jumping exercises, resistance training, progressive resistance training, postural control exercises, flexibility exercises, gait training, agility exercises, endurance training, functional floor exercises and backward chaining exercises. Moreover, exercises can increase functional capabilities, and correcting skills can minimize the number of falls in older population

Hvilke utfordringer møter frivillige arbeidere og hvordan dette påvirker deres arbeid

Formålet med denne oppgaven har vært å se på de utfordringene som frivillige arbeidere møter på i utførelsen av deres arbeid og hvordan dette påvirker de og deres arbeid. Oppgaven vinkles fra de frivillige sin side og er basert på narrativ analyse med hjelp av 6 kvalitative intervjuer med personer som enten er eller har vært frivillig arbeider. Kravet for informantene er at de har drevet med frivillig arbeid sammenhengende i minst 6 måneder og kan ha drevet med alle typer frivillighet som i en frivillig organisasjon, frivillig organisert hjelp, frivillige tiltak osv., så lenge det er frivillig og ikke fått betalt. Informantene i denne oppgaven har drevet med ulike former for frivillig arbeid og hver av informantene har også ulik grad av innfang når det kommer til hvor lenge de har holdt på med frivillig arbeid. Dermed ser oppgaven nærmere på de personlige erfaringene til de ulike informantene som frivillig arbeider og hvilke utfordringer de møtte på basert på deres narrativer. Det er veldig lite av tidligere forskning som ser på de utfordringene frivillige arbeidere møter på og dermed lite forskning å sammenligne dette imot. Derimot viser ferske tall at det er stadig færre som velger å bli frivillig arbeider og dette er alarmerende ettersom den norske velferdsstatsmodellen har blitt veldig avhengig av den frivillige sektoren etter NPM (New Public Managements) sitt inntog. Samtidig er det en god del av teori og tidligere forskning med fokus på profesjonsutøvere av sosialt arbeids utfordringer som ganske aktuelle ettersom mange av oppgavene som tidligere var antatt en del av profesjonsutøvere og statens oppgave, har i større grad falt på de frivilliges skuldre også. Derfor har valget falt på teori som NPM, Lipskys teori om bakkebyråkrater, Abbots jurisdiksjon og ikke minst «Self-determination theory» av psykologene Edward Deci og Richard Ryan som utgangspunkt for teorivalg i denne oppgaven. Funnene kommer fram i kapittel 4 «Data og funn» og blir diskutert i kapittel 5 «Drøfting». Etter å ha gjennomført intervjuene var mange av de faktorene som ble sagt basert på «Utfordringer knyttet til motivasjon», «Utfordringer knyttet til forhold med ledere og kollegaer», «Utfordringer knyttet til brukere og arbeidsoppgaver» og «hvordan de jobbet med seg selv/ Utfordringer ved det». Funnene som kommer her er blant annet at andre etater sine arbeidsoppgaver som NAV,UDI faller på de frivillige, forlengelse av andre systemer som delvis ikke fungerer som det skal og at frivillig arbeid kan ofte bli et moralsk ansvar og plikt oppfyllende er blant noen av de forklaringene som kommer fram

Status of Multi-Geared Small Scale Fishery Operated in Koggala Lagoon and Adjacent Coastal Area

Management of multi-species and multi-geared fisheries is challenging due to conflicts and competitions of fishers. However, such a complex fishery exists for the last 100 years in Koggala lagoon, which extends only for 727 ha area, in southern Sri Lanka. This study evaluated the fish catch and income sharing mechanisms which enable to survive these fisheries in highly dynamic biological and socio-economical environments. Eight landing sites at the lagoon body, lagoon mouth and adjacent coast were weekly visited from April to August 2015 in drawing random samples to determine gear-based catch per unit effort (CPUE), species diversity and income levels. Questionnaires and discussions among fishers were used to identify potentials and threats for the fishery. Dominant 25 fish species and 6 shrimp species were observed in the catches of 11 fishing methods including snares, a fish trap which was not recorded from Koggala lagoon. During the study period high variations of CPUE were observed within and among fishing methods. Hierarchical cluster analysis based on present-absent data showed two clearly separated clusters (P<0.05). Though the educational level and years of experience significantly differed between lagoon and coastal fishers (P<0.05), the respective income was not significantly different. Targeting different species and different life history stages by different types of gear seems to be the key in sustaining multi-geared fisheries in the lagoon for last 100 years. Though school education does not have any effect on selecting fishing location, fishing experience seems to be important in operating some specific gear. Species aggregation and their susceptibility for different gear reveled in this study must be important in developing fishery management strategies for the lagoon. Despite to the effective catch sharing mechanism, the sand bar formation, which is the most concerned issue by both lagoon and coastal fishers, will determine whether Koggala lagoon fisheries will survived for another 100 years due to its effects on altering species diversity.Keywords: Artisanal fisheries, Catch composition, Socio-economic statu

How Artisanal Stake-seine Fishery Survived for Last 300 Years in the Dynamic and Competitive Environment?

Despite to the high fishing pressure; use of illegal fishing methods; deforestation, manufacturing, tourism and even the dynamic market environment, an artisanal stake-net fishery, which operates for shrimps, has been able to survive since 1721 in Negombo lagoon in the western Sri Lanka. The key strength of the stake-net fishery is its community-based management systems which closely related with the ecosystem. But sustainable-utilisation is practically difficult in developing countries because assessing resources, setting limits on their utilisation, monitoring and enforcing complex regulations is not easy where government agencies do not have sufficient capacity for collecting data. Therefore, the present status of stake-net fishery management system in present competitive environment was evaluated. The Rapid Appraisal method was used, in gathering information on the community-based management system, by contacting active fishermen; community leaders; fish collectors; and auctioneers from 2011-2013. The equitability of sharing resources by a rotational lots drawing system for distributing access rights to fishing sites among members was identified as the key feature in limiting the fishing pressure resulting low conflicts and sustainable resource usage. Access right is tightly restricted to "culturally-homogeneous" eligible members. Loyalty of fishermen to uphold the Stake-net fishery management system remains strong. Loss of fishing sites due to siltation dramatically increased over the last 4-5 years. However, there is no guarantee that the cumulative past experience of a society will necessarily fit them to solve new problems & threats. Anyhow, successful community-based stake-net fishery management provides a useful blueprint upon which the management of other fisheries might be based.Keywords: Management: Community and Co-management, Fisheries Management, Fisheries Economic

Pleustonic colonies of cnidarians (Physalia physalis, Porpita porpita and Velella velella) found along the coastal belt of Sri Lanka

Three species of the free-floating, colonial hydrozoans namely Physalia physalis L., Porpita porpita L. and Velella velella L., found along the coastal belt of Sri Lanka are reported here with their morphological descriptions and respective abundance. The study was conducted from March 2017 to April 2018, implementing monthly coastal surveys at 26 sampling stations along the coastal belt of Sri Lanka. The abundance of stranded colonies of those species was assessed using line transects and the specimens were identified taxonomically. Of the porpitids found in this study, V. velella was reported for the first time in Sri Lankan waters while P. porpita was re-reported trustworthy as its initial record was just a sighting. The siphonophore P. physalis was also re-reported and it always represented the lowest abundance among the stranded colonies of the three species. The highest abundance of all the species was from May to August on the southwest coast of Sri Lanka, and from November to February on the northeast coast. There was a significant size difference in colonies of each species between the two coasts