scholarly journals Use of Spline Functions for Premium Rating by Geographic Area

1989 ◽  
Vol 19 (1) ◽  
pp. 91-122 ◽  
Author(s):  
G. C. Taylor
Keyword(s):  
Goodness Of Fit ◽  
Geographic Area ◽  
Spline Functions ◽  
Bivariate Splines ◽  
Contour Maps ◽  
Bivariate Spline ◽  
Spline Surfaces ◽  
Insurance Portfolio ◽  
Selection Of

AbstractThe paper gives details of a case study in the premium rating of a Householders Contents insurance portfolio. The rating is performed by the fitting of bivariate spline functions to a version of operating ratio described in Section 3.The use of bivariate splines requires a small amount of mathematical equipment, which is developed in Section 4. The fitting of splines, using regression is carried out in Sections 5 and 6, where the numerical results are given, including some assessment of goodness-of-fit.Contour maps of the spline surfaces are also given, and used for the selection of geographic areas used for premium rating purposes. These are compared with the areas, past and present, actually used by the insurer concerned.

scholarly journals Effectiveness Analysis of Spline Surfaces Creating Methods for Shell Structures Modelling

2021 ◽  
Vol 20 ◽  
pp. 41-53
Author(s):  
Grzegorz Lenda ◽  
Dominika Spytkowska
Keyword(s):  
Laser Scanning ◽  
Model Fitting ◽  
Shell Structures ◽  
Spline Functions ◽  
Software Packages ◽  
Spline Surfaces ◽  
Modelling Techniques ◽  
Manual Selection ◽  
Modelling Efficiency ◽  
Selection Of

The shape of the surface of shell structures, measured by laser scanning, can be modelled using approximating spline functions. Since the 1990s, several modelling techniques have been developed: based on points, meshes, areas outlined on meshes, regions grouping areas with a similar structure. The most effective of them have been used in modern software, but their implementations differ significantly. The most important differences concern the accuracy of modelling, especially places with rapid shape changes, including edges. The differences also affect the mathematical complexity of the created model (the number of unknowns) and the time of its development. These factors contribute to the effectiveness of modelling. Some methods work fully automatically, others allow manual selection of certain parameters, there are also methods that require full manual control. Their selection and application is greatly affected by the user’s intuition and knowledge in the field of creating such surfaces. This study tested the influence of the above factors on the modelling efficiency. A total of six methods of creating spline surfaces were analysed in three software packages of different classes: Geomagic Design X, Solidworks and RhinoResurf. The analyses were carried out on a shell structure of complex shape, consisting of seven patches separated by edges. The created models were assessed in terms of their accuracy of fitting into the point cloud. Additionally, the complexity of the model expressed in the number of control points and the time of its development were determined. The results confirmed the validity of the four methods in terms of model fitting accuracy. The best results were achieved using the semi-automatic method in the most advanced software package and the manual method in the simplest package. This has confirmed the great importance of user experience in terms of theoretical properties of spline functions. However, complexity and development time did not show a direct relationship with the accuracy of the models created. ANALIZA EFEKTYWNOŚCI METOD TWORZENIA POWIERZCHNI SKLEJANYCH DLA MODELOWANIA OBIEKTÓW POWŁOKOWYCH Modelowanie kształtu powierzchni obiektów powłokowych, pomierzonych za pomocą skaningu laserowego, można przeprowadzić za pomocą aproksymacyjnych funkcji sklejanych. Funkcje te dobrze przybliżają kształty o ciągłej krzywiźnie, jakimi są powłoki, jednocześnie wykazując spadki dokładności w miejscach zerwania tej ciągłości. Od lat 90. XX wieku rozwinęło się kilka technik modelowania za ich pomocą, m.in.: wykorzystujących same punkty, siatki mesh, obszary obrysowane na siatkach mesh, regiony grupujące obszary o podobnej strukturze. Najbardziej skuteczne z nich zostały zastosowane we współczesnym oprogramowaniu, ale ich implementacje znacząco się pomiędzy sobą różnią. Najważniejsze różnice dotyczą dokładności modelowania, szczególnie miejsc o szybkich zmianach kształtu, włączając w nie krawędzie. Różnice dotyczą też złożoności matematycznej utworzonego modelu (liczby niewiadomych) oraz czasu jego opracowania. Czynniki te składają się na efektywność modelowania. Część metod działa w pełni automatycznie, inne pozwalają na ręczny dobór pewnych parametrów, są też metody wymagające pełnego sterowania ręcznego. W ich wyborze i stosowaniu duże znaczenie ma intuicja i wiedza użytkownika w zakresie tworzenia tego typu powierzchni. W opracowaniu przetestowano wpływ powyższych czynników na efektywność modelowania. Badaniom poddano łącznie sześć metod tworzenia powierzchni sklejanych w trzech pakietach oprogramowania różnej klasy: Geomagic Design X, Solidworks i RhinoResurf. Analizy przeprowadzono na obiekcie powłokowym o złożonym kształcie, składającym się z siedmiu płatów rozdzielonych krawędziami. Został on pomierzony metodą skaningu laserowego, a scalona chmura punktów stanowiła podstawę do modelowania za pomocą funkcji sklejanych. Utworzone modele oceniono pod względem dokładności wpasowania w chmurę punktów za pomocą wykresów odchyłek punktów od powierzchni, odchyłek średnich oraz maksymalnych. Dodatkowo określono złożoność modelu wyrażoną liczbą punktów kontrolnych oraz czas jego opracowania. Wyniki pozwoliły na potwierdzenie skuteczności czterech metod w zakresie dokładności wpasowania modeli. Najlepsze efekty osiągnięto stosując metodę półautomatyczną w najbardziej zaawansowanym pakiecie oprogramowania oraz metodę ręczną w najprostszym z pakietów. Potwierdza to duże znaczenie doświadczenia użytkownika w zakresie teoretycznych własności funkcji sklejanych. Złożoność i czas opracowania nie wykazywały natomiast bezpośredniego związku z dokładnością tworzonych modeli.

scholarly journals Process-based selection of copula types for flood peak-volume relationships in Northwest Austria: a case study

2016 ◽  
Vol 46 (4) ◽  
pp. 245-268 ◽  
Author(s):  
Silvia Kohnová ◽  
Ladislav Gaál ◽  
Tomáš Bacigál ◽  
Ján Szolgay ◽  
Kamila Hlavčová ◽  
...  
Keyword(s):  
Sample Size ◽  
Goodness Of Fit ◽  
Real Life ◽  
Flash Floods ◽  
Flood Events ◽  
Copula Models ◽  
Flood Peak ◽  
Flood Peaks ◽  
Selection Of

Abstract The case study aims at selecting optimal bivariate copula models of the relationships between flood peaks and flood volumes from a regional perspective with a particular focus on flood generation processes. Besides the traditional approach that deals with the annual maxima of flood events, the current analysis also includes all independent flood events. The target region is located in the northwest of Austria; it consists of 69 small and mid-sized catchments. On the basis of the hourly runoff data from the period 1976- 2007, independent flood events were identified and assigned to one of the following three types of flood categories: synoptic floods, flash floods and snowmelt floods. Flood events in the given catchment are considered independent when they originate from different synoptic situations. Nine commonly-used copula types were fitted to the flood peak - flood volume pairs at each site. In this step, two databases were used: i) a process-based selection of all the independent flood events (three data samples at each catchment) and ii) the annual maxima of the flood peaks and the respective flood volumes regardless of the flood processes (one data sample per catchment). The goodness-of-fit of the nine copula types was examined on a regional basis throughout all the catchments. It was concluded that (1) the copula models for the flood processes are discernible locally; (2) the Clayton copula provides an unacceptable performance for all three processes as well as in the case of the annual maxima; (3) the rejection of the other copula types depends on the flood type and the sample size; (4) there are differences in the copulas with the best fits: for synoptic and flash floods, the best performance is associated with the extreme value copulas; for snowmelt floods, the Frank copula fits the best; while in the case of the annual maxima, no firm conclusion could be made due to the number of copulas with similarly acceptable overall performances. The general conclusion from this case study is that treating flood processes separately is beneficial; however, the usually available sample size in such real life studies is not sufficient to give generally valid recommendations for engineering design tasks.

scholarly journals Calibrating a flow model in an irrigation network: Case study in Alicante, Spain

2017 ◽  
Vol 15 (1) ◽  
pp. e1202 ◽  
Author(s):  
Modesto Pérez-Sánchez ◽  
Francisco J. Sánchez-Romero ◽  
Helena M. Ramos ◽  
P. Amparo López-Jiménez
Keyword(s):  
Goodness Of Fit ◽  
Decision Tool ◽  
Irrigation Network ◽  
Operation Analysis ◽  
Hydraulic Machines ◽  
Flow Assignment ◽  
Error Index ◽  
Flows Over Time ◽  
Selection Of

The usefulness of models depends on their validation in a calibration process, ensuring that simulated flows and pressure values in any line are really occurring and, therefore, becoming a powerful decision tool for many aspects in the network management (i.e., selection of hydraulic machines in pumped systems, reduction of the installed power in operation, analysis of theoretical energy recovery). A new proposed method to assign consumptions patterns and to determine flows over time in irrigation networks is calibrated in the present research. As novelty, the present paper proposes a robust calibration strategy for flow assignment in lines, based on some key performance indicators (KPIF) coming from traditional hydrological models: Nash-Sutcliffe coefficient (non-dimensional index), root relative square error (error index) and percent bias (tendency index). The proposed strategy for calibration was applied to a real case in Alicante (Spain), with a goodness of fit considered as “very good” in many indicators. KPIF parameters observed present a satisfactory goodness of fit of the series, considering their repeatability. Average Nash-Sutcliffe coefficient value oscillated between 0.30 and 0.63, average percent bias values were below 10% in all the range, and average root relative square error values varied between 0.65 and 0.80.

Small Computer System for Micrograph Analysis

1981 ◽  
Vol 39 ◽  
pp. 270-271
Author(s):  
J. F. Hainfeld ◽  
J. S. Wall
Keyword(s):  
Large Range ◽  
Small Computer ◽  
Black And White ◽  
Contour Maps ◽  
Points Of Interest ◽  
Computer Aided Analysis ◽  
Specialized Hardware ◽  
Additional Memory ◽  
Selection Of ◽  
Publication Quality

Cost reduction and availability of specialized hardware for image processing have made it reasonable to purchase a stand-alone interactive work station for computer aided analysis of micrographs. Some features of such a system are: 1) Ease of selection of points of interest on the micrograph. A cursor can be quickly positioned and coordinates entered with a switch. 2) The image can be nondestructively zoomed to a higher magnification for closer examination and roaming (panning) can be done around the picture. 3) Contrast and brightness of the picture can be varied over a very large range by changing the display look-up tables. 4) Marking items of interest can be done by drawing circles, vectors or alphanumerics on an additional memory plane so that the picture data remains intact. 5) Color pictures can easily be produced. Since the human eye can detect many more colors than gray levels, often a color encoded micrograph reveals many features not readily apparent with a black and white display. Colors can be used to construct contour maps of objects of interest. 6) Publication quality prints can easily be produced by taking pictures with a standard camera of the T.V. monitor screen.

Topik-Topik Komunikasi Dakwah Dalam Mesej Akidah Kepada Masyarakat Orang Asli di Selangor

Sains Insani ◽  
2018 ◽  
Vol 3 (2) ◽  
pp. 15-21
Author(s):  
Zulkefli Aini ◽  
Abdul Ghafar Don ◽  
Ahmad Irdha Mokhtar ◽  
Nur Uswah Ahmad Fauzi
Keyword(s):  
Qualitative Study ◽  
Study Design ◽  
Verbal Feedback ◽  
Structured Interviews ◽  
Orang Asli ◽  
Case Study Design ◽  
Beliefs And Practice ◽  
Islamic Faith ◽  
Selection Of

One of the factors that can affect a person's behavior is a communication message. In the context of the da`wah, preachers who involved actively in da`wah communication with the Orang Asli should be able to ensure that the message conveyed can be understood by the target group. In addition, the selection of the correct messages of da`wah based on the foremost priority simplify the process of sharing information between the preachers and the Orang Asli. Accordingly, this article aims to identify specific topics of Islamic faith (akidah) submitted by the Orang Asli in the process of da`wah communication and to identify verbal feedback given by the preachers to the Orang Asli of the topics. This qualitative study using case study design and data was collected through semi-structured interviews. Interviews involving nine preachers were active in da`wah activity to the Orang Asli community in Selangor. Data were analyzed thematically according to the specified objectives. The study found that the topics frequently raised by the Orang Asli is concerned about belief in Allah, belief in Malaikat, and belief in Qada' and Qadar. The topics may be found within the framework of worldview in their beliefs and practice of ancient traditions. Therefore, the preachers gave verbal feedback on these topics is based on a clear and precise sample corresponding to the level of their thinking. The emphasis on these topics is very important to strengthen and purify the faith of the community.Keywords: Communication; Message; Preacher; Indigenous community Abstrak: Elemen mesej dalam komunikasi merupakan salah satu faktor yang dapat memberi kesan terhadap perubahan tingkah laku seseorang. Dalam konteks dakwah, pendakwah yang terlibat dalam proses komunikasi dakwah dengan Orang Asli seharusnya berkebolehan memastikan kandungan mesej yang disampaikan boleh difahami oleh sasaran dakwahnya. Di samping itu, pemilihan mesej dakwah yang betul mengikut keutamaan memudahkan proses perkongsian maklumat antara pendakwah dengan Orang Asli. Sehubungan dengan itu, artikel ini bertujuan untuk mengenalpasti topik-topik tertentu dalam mesej akidah yang dikemukakan oleh masyarakat Orang Asli kepada pendakwah dan mengenalpasti maklum balas lisan yang diberikan oleh pendakwah kepada Orang Asli terhadap topik tersebut. Kajian kualitatif ini menggunakan reka bentuk kajian kes dengan pengumpulan data melalui temu bual separa struktur. Temu bual melibatkan sembilan orang pendakwah yang aktif dalam aktiviti dakwah masyarakat Orang Asli di Selangor. Data kajian dianalisis secara tematik mengikut objektif yang ditentukan. Kajian ini mendapati bahawa topik-topik yang sering dikemukan oleh Orang Asli kepada pendakwah dalam penyampaian mesej akidah ialah berkenaan tentang keimanan kepada Allah SWT, keimanan kepada malaikat, dan keimanan kepada qada’ dan qadar. Topik-topik berkenaan didapati berada dalam kerangka worldview kepercayaan dan amalan tradisi mereka. Sehubungan dengan itu, pendakwah memberikan maklum balas lisan terhadap topik-topik tersebut adalah berdasarkan keterangan yang jelas dan contoh yang tepat bersesuaian dengan tahap pemikiran mereka. Penekanan terhadap topik-topik tersebut merupakan perkara yang penting dalam rangka mengukuhkan dan memurnikan akidah masyarakat Orang Asli.Kata kunci: Komunikasi; Mesej; Pendakwah; Komuniti Orang Asli

scholarly journals Methodology for Determining the Location of River Ports on a Modernized Waterway Based on Non-Cost Criteria: A Case Study of the Odra River Waterway

2021 ◽  
Vol 13 (6) ◽  
pp. 3571
Author(s):  
Bogusz Wiśnicki ◽  
Dorota Dybkowska-Stefek ◽  
Justyna Relisko-Rybak ◽  
Łukasz Kolanda
Keyword(s):  
Large Scale ◽  
Multicriteria Decision Making ◽  
Research Process ◽  
Optimal Selection ◽  
Investment Projects ◽  
Odra River ◽  
Research Problems ◽  
Selection Of ◽  
Construction Works

The paper responds to research problems related to the implementation of large-scale investment projects in waterways in Europe. As part of design and construction works, it is necessary to indicate river ports that play a major role within the European transport network as intermodal nodes. This entails a number of challenges, the cardinal one being the optimal selection of port locations, taking into account the new transport, economic, and geopolitical situation that will be brought about by modernized waterways. The aim of the paper was to present an original methodology for determining port locations for modernized waterways based on non-cost criteria, as an extended multicriteria decision-making method (MCDM) and employing GIS (Geographic Information System)-based tools for spatial analysis. The methodology was designed to be applicable to the varying conditions of a river’s hydroengineering structures (free-flowing river, canalized river, and canals) and adjustable to the requirements posed by intermodal supply chains. The method was applied to study the Odra River Waterway, which allowed the formulation of recommendations regarding the application of the method in the case of different river sections at every stage of the research process.

Researching American Muslims: A Case Study of Surveillance and Racialized State Control

2021 ◽  
pp. 1-16
Author(s):  
Hajer Al-Faham
Keyword(s):  
United States ◽  
Science Research ◽  
The United States ◽  
State Control ◽  
Limited Data ◽  
American Muslims ◽  
State Repression ◽  
Second Stage ◽  
Selection Of

How does surveillance shape political science research in the United States? In comparative and international politics, there is a rich literature concerning the conduct of research amid conditions of conflict and state repression. As this literature locates “the field” in distant contexts “over there,” the United States continues to be saturated with various forms of state control. What this portends for American politics research has thus far been examined by a limited selection of scholars. Expanding on their insights, I situate “the field” in the United States and examine surveillance of American Muslims, an understudied case of racialized state control. Drawing on qualitative data from a case study of sixty-nine interviews with Arab and Black American Muslims, I argue that surveillance operated as a two-stage political mechanism that mapped onto research methodologically and substantively. In the first stage, surveillance reconfigured the researcher-researchee dynamic, hindered recruitment and access, and limited data-collection. In the second stage, surveillance colored the self-perceptions, political attitudes, and civic engagement of respondents, thereby indicating a political socialization unfolding among Muslims. The implications of this study suggest that researchers can mitigate against some, but not all, of the challenges presented by surveillance and concomitant forms of state control.

scholarly journals An Analytical Approach for the Selection of Technologies to be Integrated in a Plug&play Façade Unit: The RenoZEB Case Study

Proceedings ◽  
2021 ◽  
Vol 65 (1) ◽  
pp. 29
Author(s):  
Alessandro Pracucci ◽  
Sara Magnani ◽  
Laura Vandi ◽  
Oscar Casadei ◽  
Amaia Uriarte ◽  
...  
Keyword(s):  
Building Envelope ◽  
Design System ◽  
Decision Matrix ◽  
Design Guideline ◽  
Existing Building ◽  
Building Conditions ◽  
Zero Energy Building ◽  
System A ◽  
Selection Of

The nearly Zero Energy building (nZEB) renovation market is currently the key feature in the construction sector. RenoZEB aims to develop a systematic approach for retrofitting by assembling different technologies in a plug and play building envelope. This paper presents the methodology used to transform the RenoZEB concept in the design system. A multi-criteria decision matrix is used for the selection of the best façade technologies within the market while the analysis of the existing building conditions allows to develop a replicable approach for designing deep retrofitting intervention through a plug&play façade. The methodology appears to be a valuable support for the selection of technologies and allows to define a design guideline for the envelope.

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