15 research outputs found
Local quasi-static slamming response using a gwm strip approach
No full textThe goal of this thesis is to obtain local response due to slamming loads. The main problem is that there is no satisfactory 3D slamming model, so a strip approach is applied. Slamming loads are included in hydro-structure interaction models when fully non-linear wave loads are applied. The slamming model used is the generalized Wagner method (GWM), which is based on wedge entry in water and uses potential ow assumptions. The structural analysis is done by using _nite element analysis and an impulse response spectrum based on blast loads. The calculation procedure uses a 3D ship geometry and its motions to obtain 2D strips with their relevant velocities. These 2D strips are analyzed using GWM and pressures are calculated on the 2D strips for each element on the 3D hull. To use the pressures obtained, a temporal and spatial interpolation is applied. The resulting loads are analyzed using a quasi-static finite element model and checking whether the modes are excited near their natural frequencies. From a convergence study on a general cargo ship, the structural loads converge with increasing the number of slamming strips and decreasing time step size, this means that loads can be obtained accurately. The slamming loads are very local, a linear spatial interpolation method proved to converge faster than nearest neighbor interpolation. The number of Gauss points on the hull proved to be not important, since the mesh is already relatively _ne. The inclination angle proved to lead to an increase in velocity, but when more realistic ship motions are analyzed the sensitivity to inclination angle proved to be not so big. Quasi-static structural analysis is used to find response of the structure. Using a triangular impulse response spectrum and Fourier analysis on the loads showed a significantly large static load component to justify the quasi-static analysis.Mechanical, Maritime and Materials EngineeringMarine and Transport TechnologyShip Hydromechanics and Structures5060
How to Measure the Ergonomic Quality of User Interfaces in a Task Independent Way
No full textThe main problems of standards (e.g., ISO 9241) in the context of usability of software quality are, that they can not measure all relevant product features in a task independent way. The author presents a new approach to measuring user interface quality in a quantitative way. First, he developed a concept to describe user interfaces on a granularity level, that is detailed enough to preserve important interface characteristics, and is general enough to cover most known interface types. The author distinguishes between different types of 'interaction point'. With these kinds of interaction point several types of interface (command, menu, form-fill-in, desk-top, direct manipulation, multimedia etc) can be described. The author analysed the outcomes of three different comparative usability studies to validate the quantitative measures. The results of a published comparative usability study by someone else can be predicted. Results of six different interfaces are presented and discussed. One of the most important results is that the dialogue flexibility must exceed a threshold of 15 - measured with two of the metrics- to increase significantly the user's performanc
Progress towards eliminating tuberculosis in Ga West Municipality, Ghana: analysis of tuberculosis surveillance data, 2017
Get PDFObjective: To assess the progress made towards the actualization of the 80% reduction in incident cases, monitor trends and to assess the quality of GWM TB surveillance data from 2012 to 2016.Design: The study was descriptive secondary data analysisData Source: Tuberculosis cases recorded in the District Health Information Management Systems (DHIMS) and municipal TB registers. The Municipal TB Coordinator was interviewed for clarification on the data. A TB patient was defined as one who coughed persistently for two weeks or more.Main outcome measure: Trend of TB cases in Ga West MunicipalityResults: A total of 441 TB cases were registered of which 68.9% were smear positive. Males were (67%). Age group 35-44 years were the most affected (28.6%). The incidence rose from 21.5 (2012) to 41.6 (2015). The 2016 incidence was 40.7 (± 5.63) per 100,000 population. This is significantly different from the current national incidence of 156 (p < 0.05). Data was 95% complete. Discrepancies existed between data in registers compared to the DHIMS but were not statistically significant.Conclusion: The 80% reduction in incident cases target may not be attained by the GWM due to the rising number of incident cases. However, data quality is good.Keywords: Tuberculosis, data analysis, DHIMS 2, tuberculosis, incident casesFunding: The study was funded by the author
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Searching for gravitational wave memory bursts with the Parkes Pulsar Timing Array
No full textAnisotropic bursts of gravitational radiation produced by events such as supermassive black hole mergers leave permanent imprints on space. Such gravitational wave 'memory' (GWM) signals are, in principle, detectable through pulsar timing as sudden changes in the apparent pulse frequency of a pulsar. If an array of pulsars is monitored as a GWM signal passes over the Earth, the pulsars would simultaneously appear to change pulse frequency by an amount that varies with their sky position in a quadrupolar fashion. Here, we describe a search algorithm for such events and apply the algorithm to approximately six years of data from the Parkes Pulsar Timing Array. We find no GWM events and set an upper bound on the rate for events which could have been detected. We show, using simple models of black hole coalescence rates, that this non-detection is not unexpected.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000350272200043&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Astronomy & AstrophysicsSCI(E)[email protected]
Über die Quantifizierung der beiden software-ergonomischen Richtlinien 'Feedback' und 'Flexibilität'
Get PDFThe main problems of standards (e.g. DIN 66 234, ISO 9241) in the context of usability of software quality are that they cannot measure all relevant product features in a task independent way. The author presents a new approach to measure user interface quality in a quantitative way. First, he developed a concept to describe user interfaces on a granularity level, that is detailed enough to preserve important interface characteristics, and is general enough to cover most known interface types. The author distinguishes between different types. He distinguishes between different types of 'interaction point'. With these kinds of interaction point several types of interface (CUI: command, menu, form-fill-in; GUI: desktop, direct manipulation, multimedia, etc) can be described. The author carried out two different comparative usability studies to validate the quantitative measures. The results of one other published comparative usability can be predicted. Results of six different interfaces are presented and discussed. One of the most important results is that the dialogue flexibility must exceed a threshold of 15 - measured with two of the metrics - to significantly increase the usabilit
The Impact of Chinese Vehicles on the Estonian Car Market
No full textLõputöös „Hiina sõidukite mõju Eesti autoturule“ autor on uurinud aastal 2024 Hiina sõidukite mõju, kuna iga aastaga rohkem ettevõtteid hakkavad pakkuma müügiks uued Hiinast töödeldud sõiduautod. Hiina sõiduautode teema autori jaoks tekitab huvi ja lisaks ettevõte Eurostauto OÜ, kus autor töötab, alustas aastal 2024 Hiina sõiduautode müügiga. Sellest kaasnes ka autori jaoks teema valik.
Lõputöö esimeses osas autor tutvustab lugejad Hiina sõiduautode toomise ajalooga ning Eestis pakutud sõidukitega. Autor on välja toonud sõiduautode tootjade lühi tutvustust, sõidukite tehnilisi andmeid ning sõidukite hinnad. Lisaks autor on tutvustanud lugejad sõidukite maaletoojatega. Lõputöö esimeses osas lisaks analüüsib autor Eesti sõiduautode turu müüginumbrid aastal 2024, AMTEL – i andmete põhjal. Tänu AMTEL – i tabelitele suutis autor saada täpsed müüginumbrid aastal 2024.
Lõputöö teises osas autor on võrrelnud Hiinast sõiduautosi teiste kaubamarkide sõidukitega. Autor võrdles sõidukite parameetrid, sh. sõidukite hind, sõidukitel kehtiv garantii, müügi numbrid, võimsus ning sõiduulatus elektri sõidukite juhul. Otto mootori sõidukite puhul autor võrdles kütusekulud. Samas lõputöö teises osas autor võrdles sõidukite hoolduse hinnakirjad, sõidukite garantii perioodi ajal. Autori poolt kõige mahukam osa oli teostada sõidukite proovisõidud. Autor kokku on teinud 5 erinevat proovisõidu Hiina sõiduautodega. Autor on välja toonud iga sõiduauto kohta objektiivse arvamuse, mida ilma proovisõitu ei oleks võimalik teha. Autori poolt koostatud küsimustikule on vastanud 152 inimest. Küsimustiku andmete tulemused on välja toodud lõputöö teises osas. Autor läbiviis küsimustiku Eurostauto OÜ esinduses, küsitledes inimesi elus peale nende sõidukite hooldust. Lisaks autor avaldas küsimustiku sotsiaalmeedias, ja kogus 49 vastamist interneti kaudu.
Lõputöö kolmandas osas autor on teinud järeldused antud teema kohta. Samas autor on avaldanud oma poolt ettepanekud, kuidas on võimalik kasvatada Hiina sõiduautode müüginumbrid Eestis. Autori nägemuses DFSK mudelite põhjal potentsiaalne klient on vanusega 45+. GWM mudelite potentsiaalne klient on 25 – 40 aastat vana. Lynk&Co sõidukite potentsiaalne klient on inimene kes on terve elu sõitnud Volvo sõiduautoga, ja on soov proovida midagi uut. BYD sõidukite mudeli valik on kõige laiem. Tänu sellel rohkem inimesi soovivad osta endale just BYD sõidukit. Samas autor on jõudnud järelduseni, et on vaja teha veel palju tööd selle peale, et inimesed hakkaksid ostma Hiina sõiduautod. Oleks vaja läbi töötata hoolduse hinnakirjad, seal samas hoolduse intervallid ja maksumused. Tavalist inimest ei ole võimalik huvitata sõidukiga mis on natuke odavam. Hiina sõidukite hind peaks olema 30% madalam kui nende esimese konkurendi hind. Sellel juhul on võimalik alustada sõidukite müügiga suuremates numbrites.
Antud lõputöö annab ülevaade sõiduautode müügi ettevõtetele probleemidele, mida on vaja lahendada sõidukite eduka müügi jaoks. Samas ka maaletoojate jaoks antud lõputöö on kasulik, sest näitab aspekte mida oleks vaja lobitöödeta lähimas tulevikus. Tavaline tarbija, antud lõputöö raames tutvustab enda jaoks Hiina sõiduautod mis on pakutud Eesti turul.In the thesis "The Impact of Chinese Vehicles on the Estonian Car Market," the author investigates the influence of Chinese vehicles in 2024, as more companies begin to offer newly manufactured cars from China for sale each year. The topic of Chinese vehicles is of particular interest to the author, especially since the company Eurostauto OÜ, where the author works, began selling Chinese cars in 2024. This led to the author choosing the topic.
In the first section of the thesis, the author introduces the history of importing Chinese vehicles and the vehicles offered in Estonia. The author provides a brief introduction to car manufacturers, technical specifications, and vehicle prices. Additionally, the author introduces the readers to vehicle importers. In this section, the author also analyzes the sales figures for Estonian vehicles in 2024 based on AMTEL data. Thanks to AMTEL’s tables, the author was able to obtain accurate sales figures for 2024.
In the second section of the thesis, the author compares Chinese vehicles with vehicles from other brands. The author compares vehicle parameters such as price, warranty, sales numbers, power, and driving range for electric vehicles. For internal combustion engine vehicles, fuel consumption was compared. Furthermore, the author compares maintenance price lists and the warranty period for vehicles. One of the most substantial parts of the thesis involved conducting test drives. The author performed a total of five different test drives with Chinese vehicles and provided an objective opinion on each vehicle, which would not have been possible without the test drives. The author’s survey was answered by 152 people. The results of the survey are presented in the second section of the thesis. The survey was conducted at the Eurostauto OÜ showroom, where people were interviewed after their vehicle maintenance. Additionally, the author published the survey on social media, receiving 49 responses online.
In the third section of the thesis, the author presents conclusions regarding the topic. The author also provides recommendations on how to increase the sales of Chinese vehicles in Estonia. According to the author’s vision, the potential customer for DFSK models is someone aged 45 and older. The potential customer for GWM models is between 25 and 40 years old. The potential customer for Lynk&Co vehicles is someone who has driven a Volvo their entire life and is looking to try something new. The BYD vehicle range has the widest selection, which is why more people are interested in purchasing BYD cars. However, the author concludes that much work is still needed to encourage people to buy Chinese cars. Maintenance price lists, intervals, and costs need to be refined. A regular consumer is unlikely to be attracted to a vehicle that is only slightly cheaper. The price of Chinese vehicles should be 30% lower than that of their closest competitor in order to start selling vehicles in larger numbers.
This thesis provides an overview of the challenges faced by car sales companies that need to be addressed for successful vehicle sales. Additionally, the thesis is also useful for importers, as it highlights aspects that need attention in the near future. For the average consumer, this thesis introduces Chinese vehicles available on the Estonian market
Hydro-elastic response of ship structures to slamming induced whipping
No full textSlamming induced whipping can significantly increase the structural loading of ships. Although this is well-known, the whipping contribution to the structural loading is rarely taken into account when computing the structural loading. An exception are the "dynamic loading" factors found in Classification Societies rules. Currently there are no commercial tools available to compute the seakeeping response including slamming induced whipping. This is the main reason for not accounting for the effects of whipping. Extensive research has been done on the subject of slamming impact and whipping response but an integral and computationally efficient method is not yet available for ship structure designers. This is the starting point for this research presented in this thesis. The objective of this thesis is: "The development of a practical method to calculate the global and local response of the ship structure due to the seakeeping loading including the slamming loading. This method should contain the full hydro-elastic coupling." This method is developed by combining well-known components and new tools. The concept of generalised modes is used to solve the hydro-elastic seakeeping problem. All degrees of freedom of the ship structure are described by mode shapes using this approach, even the rigid-body modes. The number of degrees of freedom may be arbitrary selected by the user. The flexible mode shapes of the structure are obtained from either a 3D-FEM analysis or a 1D-FEM analysis using a beam model of the ship structure. The seakeeping response of all modes, rigid and flexible, is solved simultaneously which ensures a full account for the hydro-elastic coupling. The seakeeping response is solved in the time domain using a 3D surface integration method. The time domain allows one to include non-linear load components and to calculate the transient response with relative ease. The non-linear Froude-Krylov and non-linear hydrostatic loads are taken into account to improve the seakeeping and internal load predictions. The diffraction and radiation loads are kept linear to allow for reasonably fast computations. The linear diffraction and radiation coefficients are solved in the frequency domain using a 3D boundary element method. This hydro-elastic approach allows one to compute the transient whipping response. The springing response can only be partially predicted because springing is often caused by additional non-linear load components which are not included in the presented theory. Since fast and robust, non-empirical 3D methods are not yet available for the calculation of the slamming loads, the slamming loads are solved using 2D methods. The first of the two used methods is the Generalised Wagner Model (GWM). This is the most accurate of the two methods. The second method is the Modified Logvinovich Model (MLM) which is much faster compared to the GWM. The drawback of using these 2D methods is that the slamming loading can only be computed accurately for head seas and near head sea conditions. The computation of the slamming loads is directly integrated into the time domain seakeeping calculation. At every time step the slamming loads are computed based on the actual relative motions, and the computed slamming loads are taken into account for the solution of the resulting motions. Insight into the global response of the ship structure is obtained by using the modal approach for computing the seakeeping response. However, it is difficult to compute the local structural response of a ship structure using the modal method. Therefore, the local structural response is computed by transferring the seakeeping loads to the 3D-FEM model of the structure and solving the response using the FEM method. The method used ensures that the hydrodynamic loads at the structural model are well balanced by the applied nodal acceleration loads, thus ensuring a consistent FEM solution. These nodal acceleration loads allow one to include the effect of whipping even when a quasi-static FEM approach is used. The developed methodology is verified and validated using different ships, results of model experiments and the results of one full-scale sea trial. All verifications show that the developed approach gives the expected results and that the presented theory is consistent. The slamming forces are verified using model experiments of a container ship and an aluminium model. This validation shows that it is necessary to take into account the static bow wave generated by the blunt bow of the container ship when computing the slamming loads to a reasonable accuracy. The validations using experiments with the aluminium model show that the contribution of the added mass on the natural frequency is well predicted, even for conditions with forward speed. The calculated slamming loads and resulting whipping response compare well with the experimental results of the aluminium model. Stresses measured during a sea trial of the M-Frigate of the Royal Netherlands Navy are also used to validate the developed methodology. The computed spectral energy of the wave frequency and the whipping response are close to the spectra measured. The Weibull fits of the extremes of the calculated and measured stresses shows very good agreement, the hog/sag ratio is also well predicted. The stresses are slightly overpredicted for the highest speed. Two ultra large container ships are used for a case study. Design values such as the expected ultimate bending moment and fatigue loading are calculated based on the computed bending moment or stress history. It is shown that the seakeeping response should be calculated for at least 750 wave encounters in order to accurately compute the design values. The developed seakeeping method is fast and robust enough to compute the design values for all cells of a scatter diagram. The expected ultimate bending moment and fatigue damage are calculated based on a life-time of thirty years with both North Atlantic and World wide scatter diagrams. It is shown that the slamming induced whipping and the computed springing response reduce the predicted fatigue lifetime by about forty percent and increase the expected ultimate bending moment by about twenty percent. This shows the importance of accounting for these effects when computing the design values for such flexible ships. It can be concluded that a practical method to calculate the global and local response of the ship structure due to the seakeeping loading including the slamming loading and whipping has been developed. It is shown that the developed method can be applied to calculate the design values for a complete scatter diagram. The validations shows that the predictions are reasonably accurate.Marine & Transport TechnologyMechanical, Maritime and Materials Engineerin
Review of \u3ci\u3e Out Our Way: Gay and Lesbian Life in the Country\u3c/i\u3e By Michael Riordon
Get PDFMichael Riordon, radio playwright and author of The First Stone: Homosexuality and the United Church (1990), is obviously a master interviewer. From meetings with some three hundred gay men and lesbians in rural Canada, he distills the personal narratives of subjects from the pseudonymous tightly closeted to local semi-acknowledged characters and internationally known figures such as writer Jane Rule or Jim Egan, recent challenger to the Canadian Charter of Rights. Quotable nuggets of wisdom and sharp human observation come from all, often marked by fear, loneliness, and bigotry. Overwhelmingly, story after story echoes the phrase, I always knew I was different. And then like someone who knows pain, and who\u27s found in himself the wherewithal to deal with it, each has struck out like a pioneer to find a place to fit in and a way to cope-away from the urban sanctuary too often identified as the only locale in which gays and lesbians can survive.
Their homes, spanning the continent, are sometimes located in harsh and isolated circumstances (even under the same roof as disapproving parents and siblings), sometimes in a carefully nurtured pocket of mutual support. In contrast to the ghetto of glitz and consumerism typified by urban lifestyle magazines, perhaps the most salient feature springing from these narratives is the close, yet occasionally uneasy integration of individuals into communities where life is often lived in a fishbowl.
Riordon has himself created the impression of varied landscape by giving each of his sixty chosen pieces a descriptive title, such as GWM seeks or God\u27s country, with no byline. The lack of index of interviewees, certainly a flaw were this an academic treatise, here helps Riordon create an impressionistic snapshot of rural gay life, enhanced by cross references to where partners\u27 and friends\u27 parallel stories may be found in the anthology. This heightens the sense of precious filaments of a network and astounding geographical variety among subjects who run the gamut of mobility and rootedness
A comparison of three dual drainage models: Shallow Water vs Local Inertial vs Diffusive Wave
Get PDFThis is the author accepted manuscript. The final version is available from IWA Publishing via the DOI in this record.In this study we compared three overland flow models, a full dynamic model (SWE), a local
inertial equations model (GWM), and a diffusive wave model (PDWAVE). The three models are
coupled with the same full dynamic sewer network model (SIPSON). We adopted the volume
exchange between sewer and overland flow models, and the hydraulic head and discharge
rates at the linked manholes to evaluate differences between the models. For that purpose we
developed a novel methodology based on RGB scale. The test results of a real case study show
a close agreement between coupled models in terms of the extents of flooding, depth and
volume exchanged, despite highly complex flows and geometries. The diffusive wave model
gives slightly higher maximum flood depths and a slower propagation of the flood front when
compared to the other two models. The Local inertial model shows to slight extent higher
depths downstream as the wave front is slower than the one in the fully dynamic model.
Overall, the simplified overland models can produce comparable results to fully dynamic
models with less computational costThis research is partially funded by the FCT
(Portuguese Foundation for Science and Technology) through the Doctoral Grant
SFRH/BD/81869/2011 financed through the POPH/FSE program (Programa Operacional
Potencial Humano/Fundo Social Europeu). This study had the support of the Portuguese
Foundation for Science and Technology (FCT) Project UID/MAR/04292/2013 and the UK’s
Natural Environment Research Council (NERC) Project Susceptibility of catchments to INTense
RAinfall and flooding (SINATRA, NE/K008765/1)
Expressing segmentation in d-comics
No full textComics as a storytelling medium is constructed by panel sequences. The comics author defines how the panel sequences are segmented with specific storytelling intentions to enhance aspects such as: Curiosity, suspense, surprise, emphasis, storytelling pace, etc. In printed comics, the intended segmentations are embodied because they are physically printed on the pages. However, different electronic devices that have different screen sizes and support different ways of interaction can all gain access to the same panel sequence of d-Comics (digital comics). Therefore, the question emerges how to express author intended segmentations in d-Comics. This article collects several design prototypes that explore the relationship between narrative structure, visual space, and interaction in d-Comics. Prototype 1 discusses how the background layer can express the segmentation. Prototype 2 explores how differences in movement speed of visual layers can express segmentation. Prototype 3 visualizes different shape changes when a reader interacts with the panel sequence to express segmentations. Prototype 4 explores different layouts of panels with interactivity linked to zooming in and out. And finally, prototype 5 uses spatial distance to show segmentations
