462 research outputs found
Agent-Based Control System as a Tool towards Industry 4.0: Directed Communication Graph Approach
Agent-based control systems composed of simple locally interacting controller agents with demonstrated complex group behaviour. There have been relatively few implementations of agent-based control systems, mainly because of the difficulty of determining whether simple controller agent strategies will lead to desirable collective behaviour in a large system. The aim of this chapter is to design an agent-based control system for sets of âclusteredâ controller agents through proposed directed communication graph approach as potent tool for the Industry 4.0. To reach global coordination with focus on real world applications, we use cluster algorithm technique in a set of rules for assigning decision tasks to agents. The outcomes include behavioural pattern, trend of agents and multi-agents usage in rail manufacturing enterprise resource planning and supply chain management. The results of this study showed that the combination of multi-agent system has ability to interact effectively and make informed decision on the type of maintenance actions, resource planning, train arrival times, etc
Cultural Dichotomy and Language Learning among the Yoruba Race of Nigerian Society
This study investigated cultural diversity and second language learning among primary school pupils in Ogun state of Nigeria. The study is a descriptive survey in which 300 primary four school children were randomly selected from among pupils attending public primary schools in Ogun state. The Language Achievement Test developed and validated by the researchers was the instrument used in the study. It was a fifty items test designed to measure language skills of listening, speaking, reading and writing. Its convergent validity ranged from .68 to .91 on Cronbach alpha. Findings revealed significant influence of cultural diversity on listening, speaking, reading and writing skills of the participants. It was therefore recommended that a unified Yoruba accent and grammar should be evolved and adopted in all primary schools in all the Yoruba speaking states of Nigeria. Keywords: cultural diversity, language learning, Yoruba languag
HOW USEFUL IS CONTINGENT VALUATION OF THE ENVIRONMENT TO WATER SERVICES? EVIDENCE FROM SOUTH EAST, NIGERIA
Contingent Valuation Methods (CVM) Willingness To Pay (WTP) Tobit (censored) model Quasi-deregulation
Ileal lipoma: a rare lead point for adult ileocolic intussusception
Intussusception is the telescoping of a segment of the gastrointestinal tract within the lumen of an adjacent segment. Adult intussusceptions are rare, with ileal lipoma responsible for only 6% of cases. Clinically, adult intussusception remains an elusive diagnosis. The triad of abdominal pain, vomiting and passage of bloody stool is not frequently seen in adults. Abdominal computed tomography is the gold standard for identifying ileal lipoma as the lead point of an adult intussusception. Definitive management is by surgical excision of the involved segment. This is a case report of a 38-yearold female with intussusception with a 5-cm subserosal ileal lipoma as the lead point. This is the first (to the best of our knowledge) reported case of adult intussusception caused by ileal lipoma in Africa.Keywords: Intussusception, Ileal, Lipoma, Subserosal, Intestinal obstruction, Adul
Professionals In The Built Environment And The Incidence Of Building Collapse In Nigeria
The failure of buildings is a national problem, which not only results in waste of materials, financial and human resources but, sometimes in loss of lives and properties. This occurrence has been a challenge to the professionals in the industry and as such necessitates the need for this study. The study examines the involvement of professionals in the incidence of buildings collapse in Lagos state. The research also identified and assessed the causes of building failure, evaluated the effects of such failures on construction professionals, the client, and the nation as a whole. In achieving these objectives, the study adopts a survey technique with a total of 65 questionnaires mainly for the professionals in the industry in which 50 were retrieved and used for the analysis. Random sampling technique was used in the selecting of the sample size. Data collected were analyzed using the frequency table, mean item score, one sample t test and paired sample t test. The study revealed that the building industry is full of quacks and inexperienced contractors. Their involvement in building construction has led to a lot of collapse in the past and at present. Poor management and leadership on the part of the Site Engineers and Builders have also contributed to many buildings failures. The analysis reveals that there are significant differences in the causes of building failure. The failures of buildings also have significant effects on the stakeholders. The study recommends that for all construction works being undertaken, such should be designed and supervised by qualified and registered Engineers and Builders. Also code of ethical conduct of building profession should be strongly enforced by the bodies concerned as to prevent ethical abuse by the professionals in the industry
Self-directed learning readiness and learning style preferences of adult learners
The main purpose of the study was to identify the relationships among demographic characteristics, learning styles, and self-directed learning of adult American and foreign students. Based on adult self-directed learning and experiential learning theoretical frameworks, a conceptual model was formulated and tested;The experiential Learning Style Inventory (LSI), and the Self-directed Learning Readiness Scale (SDLRS) were used to collect data from 178 graduate students;The study is based on a correlational ex post facto research design. Descriptive statistics, analysis of variance and path-analysis were employed for testing the hypotheses of the study;The results of the study indicate that nationality and degree program directly influence readiness for self-directed learning. Also, preference for learning styles and level of education directly influence an individual\u27s level of readiness for self-directed learning;Academic major and years of prior work experience are indirectly indicative of readiness for self-directed learning;Age, gender and type of employment showed neither direct nor indirect influence on inner-outer directedness in learning; therefore they have no predictive capability for either self-directed learning readiness or preference for experiential learning style. The researcher concluded that a combination of active and abstract abilities are required for effective self-directed learning. Propensity for self-direction in learning can be enhanced. With further research, and adequate understanding of the relationships among demographic characteristics, learning preferences and readiness for self-directed learning, intervention efforts can become more feasible and productive. Implications for theory and research were highlighted, along with recommendations for further research
Design of a Heat Exchanger for a Supercritical CO2 Turbine System
This research aims at designing a shell and tube heat exchanger which will drive a turbine operated on supercritical CO2. Hot gases from boiler (simulated using air) at 1500 K is introduced into the shell to heat up the supercritical CO2 at 10 MPa flowing within tubes from 450 K to 1050 K. The design was done using selected shell and tube heat exchanger empirical equations at predefined boundary conditions. The effect of shell and tube diameter on other design parameters was examined. It was observed that the number of tubes, tube external and internal side surface area, volumes of shell and tube, overall surface area and mass of tube material increases as the shell diameter increases from 6 m to 18 m at 2 m interval and this is due to the increase in cross sectional area. The shell length, the number of baffles, overall heat transfer coefficient, the pressure drop in both shell and tube sides all decreases as shell diameter increases at same rate as described previously, and this is attributed to a reduced velocity caused by the increased cross section area of tubes and baffle space. The increase in tube diameter from 0.0092 m to 0.12 m at 0.02 m intervals however leads to an increase in shell length, volume of tube material, number of baffles, shell side pressure drop, tube side pressure drop, overall area of the device ,tube external side surface area and tube internal side surface area. However, the overall heat transfer coefficient, total length of tubes and number of tubes decreases as the tube diameter increases at same rate as described previously. A decision was made on the selected heat exchanger based on fewer tubes, reduced mass of tube materials , low shell and tube pressure drop, and a high heat transfer coefficient. A selected of shell diameter 8 m, shell length 51.62 m, tube diameter 0.102 m, number of tubes 1509 and overall heat transfer coefficient 60.51 W/m2K was considered.
A CFD analysis was conducted using ANSYS 18.1 on the prototype of the selected heat exchanger device. The device was built using the design modeler and it consist of the shell, tubes, air fluid, CO2 fluid and baffles The meshing and naming of unit parts was done while the set-up stage was achieved with the predefined boundary conditions and properties. The temperature distribution and thermal analysis of the heat exchanger was reported
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