Web crippling of cold-formed thin-walled steel cassettes

The resistance of cold-formed thin-walled cassettes against local transverse forces, i.e. the web crippling capacity, was investigated. The web crippling of cassettes, or liner trays as they are also called, was studied both experimentally and numerically using finite element modelling. Both unreinforced (flat) cassette webs and webs with longitudinal stiffeners situated on only one side of the web mid-line were studied. The calculation of the web crippling capacity of this type of stiffened webs is not included in current design codes. However, if cassettes are designed as continuous over two or more spans, the resistance against local transverse forces has to be verified. It should be noted that the original purpose of the stiffener in cassette webs is to increase the bending moment capacity by increasing the effective area of the compressed part of the web when cassettes are designed as single-span structures, in which case web crippling does not usually become critical. A total of 52 structural tests were carried out on specially manufactured single cassette web sections and built-up cassette structures. Both interior two-flange and interior one-flange loading were considered. The calculation rules for unreinforced webs given in current design codes were found to be relatively conservative in comparison to the test results. Finite element models were developed and validated on the basis of the test results and very good agreement was achieved. These models were used as a starting point for a parametric study of the influence of different cross-sectional parameters on the resistance against local transverse forces of longitudinally stiffened webs. Also the influence of the load bearing length was included in the study. Recommendations concerning the design of the cassette web section are given based on the results. It was shown that the use of a longitudinal stiffener of the studied type in fact reduces the web crippling capacity by at least 10 % in comparison to a similar cassette with an unreinforced web. Depending on the stiffener's geometry, the reduction can be considerably larger. A reduction factor equal to 0.7 - 0.9 should be used for the type of longitudinally stiffened webs considered in this study in connection with the design code formulae for the resistance of unreinforced webs against local transverse forces, depending on the cross-section geometry.reviewe

Study on Light-gauge Steel Roof Trusses with Rosette Connections

This paper describes the Rosette-joining system and its possibilities in roof-truss structures in the span range of 8 to 12 meters (26 to 39 ft). The test programme that was carried out to verify the behaviour of the Rosette-joint and the thin-walled sections is described. The test results are given and analysed where they currently exist. The results are compared with values calculated according to the 1996 U.S. (AISI) [3] code supported by a distortional buckling analysis according to the Australian / New Zealand Standard (AS) [4] and FE Analysis results

Comparison of Time Taken And Compression Efficiency For Different Sizes of Databases

Data compress for object oriented data warehousing. A data warehouse is an essential component to the decision support system. The traditional data warehouse provides only numeric and character data analysis. But as information technologies progress, complex data such as semi-structured and unstructured data become vastly used. Data Compression is of interest in business data warehousing, both because of the cost saving it offers and because of the large volume of data manipulated in many business application.[3],[5]. The entropy is used in many areas such as image processing, document images. But in our research we used the entropy in object oriented data warehousing. Creation of different sizes of databases in oracle. Employment of object oriented programming for compression using Datawarehousing

Huomiopohjaisen liiketoiminnan implikaatiot

The advent of social media has created an increasingly growing ecosystem of digital platforms that rely heavily and capitalize on human attention. The business models of attention-based businesses encourage platform developers to constantly seek new ways of drawing their customers towards their platforms and ultimately to be accessible to advertisers. Therefore, social media platform providers are fighting to teeth over how much time and engagement can they attain from their platform’s users. This study presents a descriptive review of the literature on attention-based business models and discusses the ethical issues concerning the development of persuasive technology. The thesis will focus on examining methods and consequences of attention-grabbing technologies in modern attention-based businesses, namely large social media businesses such as Meta, Twitter, and Alphabet. The review explores existing literature to identify the most topical issues at hand and maps open questions for future research. Theoretical background from psychology and behavioral economics are used to assess research findings from relevant literature related to – and around persuasive technology design and its influences. The literature shows that there are myriad biases and heuristics that social media platform providers are tapping into to maximize user engagement, even with undesirable costs to individuals and communities. Addiction, the spread of misinformation, and polarization are presented as key ramifications that harm users, undermine healthy public discourse, and fuel segregation. This thesis argues that intentionally addicting users for economic gains is wrong and that the harmful effects of persuasive technology outweigh the benefits. It provides an overview of how the current state of the attention economy is unfolding and presents transparency and dissolution of the power imbalance between end users and platform providers as possible alternatives to platforms maximizing engagement