Optimization of design formulations for reinforced concrete slabs

The predictions for flexural requirement in singly reinforced concrete slabs and sections have been assessed using the minimum weight approach and mathematical programming. Results indicate that although the predictions in the codes are safe; they are quite conservative, expensive and encourage although the predictions in the codes abuse. The value of under-estimation ranges from 17% to 27% in the codes. A more precise stress block may be necessary in order to reduce if not eliminate under-estimation. It is suggested therefore, that fully probabilistic design formulations be employed for the determination of flexural requirements of reinforced concrete slabs or sections in order to eliminate or at least minimize abuse(s) that can subsequently result into the reduction of the structural integrity or outright failure of such membersKeywords: reinforced concrete slabs, flexure, mathematical programming, design formulations code

Jumping Finite Automata for Tweet Comprehension

Every day, over one billion social media text messages are generated worldwide, which provides abundant information that can lead to improvements in lives of people through evidence-based decision making. Twitter is rich in such data but there are a number of technical challenges in comprehending tweets including ambiguity of the language used in tweets which is exacerbated in under resourced languages. This paper presents an approach based on Jumping Finite Automata for automatic comprehension of tweets. We construct a WordNet for the language of Kenya (WoLK) based on analysis of tweet structure, formalize the space of tweet variation and abstract the space on a Finite Automata. In addition, we present a software tool called Automata-Aided Tweet Comprehension (ATC) tool that takes raw tweets as input, preprocesses, recognise the syntax and extracts semantic information to 86% success rate

Appraisal and Reliability of Variable Engagement Model Prediction for Fibre Reinforced Concrete

The variable engagement model based on the stress - crack  opening displacement relationship and, which describes the behaviour of randomly oriented steel fibres composite subjected to uniaxial tension has been evaluated so as to determine the safety indices associated when the fibres are subjected to pullout and with or without bending during fracture. Results indicate that the model as used is very safe for the prediction of fibre reinforced concrete and with associated small or negligible failure probabilities, since safety indices ranged between 25 and 160 for fibres fracture without bending, while it ranges between 2 and 4 for fibres fracture with pullout and bending. Also, the associated failure probabilities of fibres with bending are from 0.5 × 10-4 to 0.14 ×10-2

Reliability Analysis of Bending, Shear and Deflection Criteria of Reinforced Concrete Slabs

Reliability analysis of the safety levels of the criteria for bending, shear and deflection of singly reinforced, concrete slabs, have been evaluated over the practical range of thicknesses 100mm to 250mm.  The First Order Reliability Method was employed in the evaluation procedure for continuous slabs of equal spans as a case study.  Results indicate that the safety margins proposed and associated with the probability of failure (given as 1 x 10-6) for singly reinforced concrete slabs, in the British [CP110; BS8110] and European [EC2] codes for design are not achieved at all.  Also, the reliability levels are not uniform.  Thus, the current design formulations are not as safe and reliable as predicted.  This is because the intrinsic probability of failure, in bending, for example, is only 0.022, which, corresponds to an implied safety level of 2.015. Therefore, the design formulations in these codes need a review so that they can at least meet the target for approved structural safety as prescribed by the Joint Committee on Structural Safety

Synthesis of regular expression problems and solutions

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Stochastic Assessment of Nigerian Wood for Bridge Decks

This presentation assures the suitability of Nigerian wood using a stochastic safety evaluation method for bridge decks. A timber bridge deck is modeled in accordance to current specifications, to represent real life experiment in order to depict the structural behavior of planks when used as bridge decks. This model is then subjected to some degree of entropy using Advance Second Moment Reliability Assessment (ASMRA) method, which is then subsequently analyzed using JAVA library with the help of Flanagan polynomial. It is observed that, strength classes, timber thicknesses and stringer spacings are the major factors among others influencing the structural behavior of Nigerian timber species proposed as bridge decks material. Therefore, the major classes of the timber recommended for bridge decks are those within the strength classes N1 to N4and with dimensions ranging from 100 x 250mm to 150 x 300mm on stringers spaced not greater than 300mm. These strength classes with their corresponding material properties can be a source of sustainable bridge decks material over a reasonable period of time as indicated by the probability of failure as a result of damage due to load accumulation. In view of this, timber which is a locally available material can be used as supplement for bridge decks to substitute for the expensive concrete and steel which are the most commonly used materials and substantially reduce the cost of decks. Also, abandoned bridges with defects only in their decks in both rural and urban locations can be effectively rehabilitated in order to improve traffic flow, economic activities and the quality of life of the people.http://dx.doi.org/10.4314/njt.v34i2.

Advances in Modern Nigerian Art and Urban Aesthetics: Osogbo Fence Beautification’s Experience

Fences and boundary demarcations are later additions to buildings, for fortification, while their ornamentation is an advancement in modern Nigerian art from the 1970s. Studies of wall decorations have focused mainly on facades of buildings and shrine walls, with little scope for ornamentations on fences of private residential buildings. This study investigates the trends in boundary demarcation in Yoruba culture, highlighting the innovations in the practice. It also classifies the forms and styles in the decoration on fences of domestic buildings, using Osogbo, a prominent city in the advancement in art and culture, since its inception. The study reveals rich and divergent styles of artistic embellishment in fences of private homes, in diverse materials. The ornamentation on fences are observed to evolve with the means of the owners and indirectly enhance the aesthetic of the environment. Keywords: Fence beautification, Fortification, Modern art, Urban Aesthetics, Osogbo. DOI: 10.7176/RHSS/10-4-01 Publication date: February 29th 202

Finite element modelling of steel poles for power production and transmissions

Materials used in civil engineering constructions display wide range in their engineering properties; a structural engineer is required to quantify the risks and advantages of using such materials. Continuous supply of electricity is essential for every nation and electric poles are been susceptible to extreme damages caused by natural hazards such as snow, wind, ice, earthquake etc. These actions can knock down poles thereby causing damage and disruption of power supply. Selecting a pole material such as steel for power transmissions will sufficiently help in distributing power due to its superior material properties. The determination of the response of the steel poles to loads is accomplished by the aid of Finite Element (FE) coded in software, ABAQUS CAE. The extent of damage as a result of deflections as per stresses and displacements were effectively measured and simulated in the software. The result in ABAQUS shows that the steel poles will not suffer any reasonable deformation when loaded indicating that steel poles material properties are sufficient to provide adequate resistance against actions such as deformations and deflections during their service lives.Keywords: Steel poles, Deformation, Finite Element, ABAQU

Automatic attendance capturing using histogram of oriented gradients on facial images

Abstract: Humans mostly use faces to identify/recognise individuals and the recent improvement in the capability of computing now allow recognition and detection automatically. However, there still exist quite a number of problems in the automatic recognition of facial images. Histogram of Oriented Gradients (HOG) has been recently adopted and seen as a standard for efficient face recognition and object detection generally. In this paper, we investigate and discuss a simple but effective approach to capturing student’s attendance register in a lecture hall by making use of HOG features for detecting and recognising students face at different moods, orientations, and illuminations. Our experiment detection and recognition output show a good performance on our facial image database obtained from the University of Johannesburg, this performance is due to HOG descriptors attributes which are robust to changes in rotation and illuminations. Our system will help to save instructional staff/lecturer time by eliminating manual calling of students name and also help monitor students

Interactive learning of factual contents using a game-like quiz

Abstract: Computer games are widely recognised for the attention they get from their players. Beyond mere games are serious games — games created to teach specific subjects or concepts. Arguably, two of the most addictive mechanisms in serious games are: the scoring design – the design of who gets what and how, and the game interface (or graphics). These mechanisms have been proven to increase the interest of gamers in such games, balancing their learning experience with the fun. Quiz systems on the other hand, are mere educational tools with little or no interesting devices. In this paper, we have proposed a new classification for some mid-point between serious games and quiz systems; suggesting an “equilibrium” by adding some fun and keeping the educational content in quiz systems. We have also reported the development of a new quiz system designed using the proposed category called Abeced. Abeced is designed with game-like interactive feedback mechanisms for testing students on factual contents across different subjects. Abeced, mimicking most serious games, is designed with an interesting interface and a voice feedback to enhance students’ learning experience. We have shown that users found Abeced more interesting because of its embedded game-like features