• Smart Structures and Systems
• /
• v.15 no.6
• /
• pp.1521-1542
• /
• 2015

The use of shape memory alloys (SMAs) in dynamical systems has an increasing importance in engineering especially due to their capacity to provide vibration reductions. In this regard, experimental tests are essential in order to show all potentialities of this kind of systems. In this work, SMA springs are incorporated in a dynamical system that consists of a one degree of freedom oscillator connected to a linear spring and a mass, which is also connected to the SMA spring. Two types of springs are investigated defining two distinct systems: a pseudoelastic and a shape memory system. The characterisation of the springs is evaluated by considering differential calorimetry scanning tests and also force-displacement tests at different temperatures. Free and forced vibration experiments are made in order to investigate the dynamical behaviour of the systems. For both systems, it is observed the capability of changing the equilibrium position due to phase transformations leading to hysteretic behaviour, or due to temperature changes which also induce phase transformations and therefore, change in stiffness. Both situations are investigated by promoting temperature changes and also pre-tension of the springs. This article shows several experimental tests that allow one to obtain a general comprehension of the dynamical behaviour of SMA systems. Results show the general thermo-mechanical behaviour of SMA dynamical systems and the obtained conclusions can be applied in distinct situations as in rotor-bearing systems.

• Earthquakes and Structures
• /
• v.13 no.1
• /
• pp.29-38
• /
• 2017

Stone masonry is one of the oldest construction types due to the natural and free availability of stones and the relatively easy construction. Since stone masonry is brittle, it is also very vulnerable and in the case of earthquakes damage, collapses and causalities are very likely to occur, as it has been seen during the last Italian earthquake in Amatrice in 2016. In the recent years, some researchers have performed experimental tests to improve the knowledge of the behaviour of stone masonry. Concurrently, there is the need to reproduce the seismic behaviour of these structures by numerical approaches, also in consideration of the high cost of experimental tests. In this work, an alternative simplified procedure to numerically reproduce the diagonal compression and shear compression tests on a rubble stone masonry is proposed within the finite element method. The proposed procedure represents the stone units as rigid bodies and the mortar as a plastic material with compression and tension inelastic behaviour calibrated based on parametric studies. The validation of the proposed model was verified by comparison with experimental data. The advantage of this simplified methodology is the use of a limited number of degrees of freedom which allows the reduction of the computational time, which leaves the possibility to carry out parametric studies that consider different wall configurations.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.29 no.6
• /
• pp.21-26
• /
• 2002

The propose of this study is to suggest objective data to be utilized for a plan and the improvement of open space through the analysis of people's behaviour and satisfaction after the introduction of an opened-fence around offices followed by a plan for wall-afforestation of public institution's. The sites examined are four offices; two of them have opened-walls and the others have traditional enclosure. Analysis of frequency is conducted to understand the actual use according to people's individual peculiarities. Pearson's correlation analysis, t-test, multiple regression analysis are carried out to find out relations of fluents. In the end, the satisfaction is high in public institution satisfaction, entrance, space perception. stability, Landscaped office with opened-fence rather than fence, and the increase in usage of fluent of public institution satisfaction, entrance, space perception. stability, confusion brings about rising of use-satisfaction. Satisfaction with the exterior of building is the most important variable that influences the whole urban open space. Furthermore the influences of the approach and stability having connection with open or not-open fence is major variable affecting satisfaction of use of open space. Whether open or not is important factor on satisfaction of open space of office building. Through this study, we can find that opened fence determines use satisfaction of resting space of outdoor-office. So factors affecting satisfaction must be regarded as important requisite on planning, design, development and management in plan for afforestation of fence at public institution.

• Computers and Concrete
• /
• v.2 no.3
• /
• pp.215-238
• /
• 2005

This work is based on a nonlinear finite-element model with proven capacity for yielding realistic predictions of the response of reinforced-concrete structures under static monotonically-increasing loading. In it, the material description relies essentially on the two key properties of triaxiality and brittleness and, thus, is simpler than those of most other material models in use. In this article, the finite-element program is successfully used in investigating the behaviour of a series of RC walls under static cyclic loading. This type of loading offers a more strenuous test of the validity of the proposed program since cracks continuously form and close during each load cycle. Such a test is considered to be essential before attempting to use the program for the analysis of concrete structures under seismic excitation in order to ensure that the solution procedure adopted is numerically stable and can accurately predict the behaviour of RC structures under such earthquake-loading conditions. This is achieved through a comparative study between the numerical predictions obtained presently from the program and available experimental data.

• Journal of the Korean Institute of Navigation
• /
• v.20 no.1
• /
• pp.47-58
• /
• 1996

The use of high tensile steel plates is increasing in the fabrication of ship and offshore structures. The main portion of ship structure is usually composed of stiffened plates. In these structures, plate buckling is one of the most important design criteria and buckling load may usually be obtained as an eigenvalue solution of the governing equations for the plate. To use the high tensile steel plate effectively, its thickness may become thin so that the occurrence of buckling is inevitable and design allowing plate buckling may be necessary. When the panel elastic buckling is allowed, it is necessary to get precise understandings about the post-buckling behaviour of thin plates. It is well known that a thin flat plate undergoes secondary buckling after initial buckling took place and the deflection of the initial buckling mode was developed. From this point of view, this paper discusses the post-buckling behaviour of thin plates under thrust including the secondary buckling phenomenon. Series of elastic large deflection analyses were performed on rectangular plates with aspect ratio 3.6 using the analytical method and the FEM.

• Steel and Composite Structures
• /
• v.2 no.5
• /
• pp.397-410
• /
• 2002

The main aim of the present paper is to present the results of a full-scale experimental investigation to study the structural behaviour of composite steel beams. The composite beam was made of cold-formed steel section shapes filled with reinforced concrete. First a comprehensive description of the experimental results in terms of: deflections, deformations, slippage and stress levels on critical steps of the load path is presented. The experimental results were then compared to theoretical values obtained by the use of an analytical model based on ultimate limit state stress blocks. Finally, a practical application of the use of this structural solution is depicted.

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 2006.07a
• /
• pp.642-642
• /
• 2006

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.17
• /
• pp.7675-7681
• /
• 2015

Background: Hazardous health behaviour in young people is an important factor that affects the individual risk for non-communicable diseases and other disorders later in life. This study aimed to determine the hazardous health behaviour of first and last class medical students of Erciyes University. Materials and Methods: This descriptive study was carried out with 240 medical students from the first and 130 students from the last (sixth) class. Data were obtained by questionnaire between March-April 2012. In total, 339 students were included with a response rate of 91.6%. Socio-demographic characteristics, school success, self-reported economic difficulties, health perceptions, hazardous health behaviour related to chronic disease, tobacco, alcohol, substance use, body weight, height, traffic, violence and nutrition were assessed in line with the literature. Results: Of the participants; 64.0% were from first and 36.0% were from the last class. Mean ages for the first and last classes were $19.4{\pm}1.5$ and $24.0{\pm}1.5years$, respectively. In the current study, males exhibited more hazardous behaviour than females. Sime 19.8% of the students in the study group used alcohol, 35.4% used a waterpipe, and 24.8% used tobacco at least once. These rates increased in both genders in the last class and the increase in males was significant. Some 3.8% of the students in the current study used pleasure-inducing illegal substances at least once. All the students participating in the current study were single, the number of males reported not using condoms (8.6%) was 4.56 times higher compared to females. Some 64.0% of the students did not perform physical activity lasting at least 30 minutes for five times a week, 13.0% did not sleep for mean 7-8 hours daily, males having a 2.9 times higher risk. More than 1/3 of the students did not consume cooked vegetable dishes and 1/4 did not consume fresh fruits and salads, the rates were higher among males. Conclusions: In the current study, hazardous health behaviour was prevalent among medical students, with higher risks among males and last class students. According to these results, medical curriculum may be focused on decreasing hazardous health behaviour. In addition, in order to prevent unhealthy behaviour, the number of youth-friendly health facilities should be increased.

• Journal of Information Science Theory and Practice
• /
• v.5 no.1
• /
• pp.15-25
• /
• 2017

Nowadays the enormous growth of modern information communication technologies and its massive use have influenced information users all over the world. Such a digital environment has drastically changed the information seeking patterns of information users of every community. These also tend law students to use various legal information sources and services in digital environments while seeking information. But there have been few empirical user studies on the aspect of digital information seeking behaviours of law students in either law or library and information science literatures. This paper aims to draw out patterns of information seeking behavior of students of law in digital environments at the University of Dhaka. A stratified random sample survey was conducted for this study. The results show that students prefer the electronic format of information rather than printed format. Major e-resources used by them and the influential factors of use were also identified in this study. This study also identified some crucial problems for seeking information and provides suggestions for the development of electronic legal information systems.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.12
• /
• pp.5989-5994
• /
• 2012

Background: There is little information on longitudinal patterns of participation in faecal occult blood test (FOBT) based colorectal cancer (CRC) screening or on demographic or behavioural factors associated with participation in re-screening. The lack of an agreed system for describing participatory behaviour over multiple rounds also hampers our ability to report, understand and make use of observed associations. Our aims were to develop a system for describing patterns of participatory behaviour in FOBT-based CRC screening programs and to identify factors associated with particular behavioural patterns. Methods: A descriptive framework was developed and applied to a data extract of screening invitation outcomes over two rounds of the NBCSP. The proportion of invitees in each behaviour category was determined and associations between behaviour patterns and demographic and program factors were identified using multivariate analyses. Results: We considered Re-Participants, Dropouts, Late Entrants and Never Participants to be the most appropriate labels for the four possible observed participatory categories after two invitation rounds. The screening participation rate of the South Australian cohort of the NBCSP remained stable over two rounds at 51%, with second round Dropouts (10.3%) being balanced by Late Entrants (10.5%). Non-Participants comprised 38.7% of invitees. Relative to Re-Participants, Dropouts were older, more likely to be female, of lower SES, had changed their place of residence between offers had a positive test result in the first round. Late Entrants tended to be in the youngest age band. Conclusions: Specific demographic characteristics are associated with behavioural sub-groups defined by responses to 2 offers of CRC screening. Targeted group-specific strategies could reduce dropout behaviour or encourage those who declined the first invitation to participate in the second round. It will be important to keep first round participants engaged in order to maximise the benefit of a CRC screening program.