14 Articles Published

1. INFLUENCE OF THE STALL TORQUE ON A VIBRO-IMPACT SYSTEM WITH NON-IDEAL EXCITATION

Authors: Dzanko Hajradinovic , Ivana Kovacic , Miodrag Zukovic

Abstract: A vibro-impact system driven by an DC electric motor is analyzed. The vibro-impact system is consisting of a crank-slider mechanism and one oscillator attached to it. Oscillator can impact in a fixed wall. The impact model has been assumed as inelastic, causing the change of velocity in sign and intensity by the restitution factor. Mathematical model which describes this system is a coupled system of second order nonlinear differential equations. The aim is to determine the influence of the stall torque on the motion of the oscillator. The system of differential equations is solved numerically. The results of the analysis are summarized in diagrams which are showing the relationship between the stall torque and the maximum amplitude of the oscillator movement, and the average value of excitation frequency of the electric motor. Frequency response diagram is also formed. Based on the diagrams regions of impact and non-impact solutions are distinguished, and regions with multiple solutio

Keywords: Vibro-impact systems; Stall torque; Impact solutions; Non-ideal excitation; Limited power supply.

Pages: 1 - 6 | DOI: 10.15224/978-1-63248-189-4-01 Page(s) : 1-6

2. DIGITAL TECHNOLOGY PRAXIS AND SHARING ECONOMY IN THE HOSPITALITY AND TOURISM INDUSTRY

Authors: Abayomi Oluwaseyi Ikumoro , Samuel Adeyinka-Ojo , Shamsul Kamariah Abdullah

Abstract: Introduction: The purpose of this study is to provide insights into emerging deployment of digital technology practices and sharing economy platform in the hospitality and tourism industry. As the digital technology displaces the traditional customer services and experience economy employee's work, it is imperative for those affected to understand the opportunities and threats of digital technology innovation on hospitality and tourism industry. Methods: Content analysis was utilized on relevant extant literature related to digital technology, disruptive digital innovation, robotics and artificial intelligence, sharing economy, collaborative economy, gig economy, platforms economy and fourth industrial revolution (IR 4.0) or industry 4.0. We identified 437-keyword counts, similar keywords were classified, combined and analysed. Results: Findings indicate digital technology praxis and sharing economy provide several opportunities in the management and advancing customer’s experience i

Keywords: Digital technology, sharing economy, opportunities, threats, hospitality and tourism industry

Pages: 7 - 11 | DOI: 10.15224/978-1-63248-189-4-02

3. COBB-DOUGLAS STOCHASTIC FRONTIER PRODUCTION APPROACH: A STUDY CASE OF MANGO PRODUCTION EFFICIENCY IN MEKONG DELTA, VIETNAM

Authors: Nguyen Thi Kim Thoa , Truong Hong Vo Tuan Kiet

Abstract: This study employed a Cobb-Douglas stochastic production frontier function to estimate the level of technical efficiency. The results of the analysis showed that cropping season of mango growers have been round year. The result of study contributed to tropical fruits efficiency of three seasons instead of only focusing on efficiency of one season or total a year. The findings revealed that season 3 ranked first in terms of technical efficiency (58.2%), followed by season 1 (53.6%) and then season 2 (49.2%). Moreover, the input variables that explained technical efficiency were fertilizer (root), fertilizer (leaf) and labor in season 1; pesticide, fertilizer (leaf) and labor in season 2; and pesticide, fertilizer (root), fertilizer (leaf) and labor in in season 3. In addition, major determinants of socioeconomic characteristics influenced positively on technical efficiency were plant density and land area in season 1 and season 3; market access, plant density and land area in season 2.

Keywords: Technical efficiency, Cobb-Douglas, mango, Mekong Delta

Pages: 12 - 16 | DOI: 10.15224/978-1-63248-189-4-03

4. ANALYSIS OF ELDERLY'S NEEDS AND USE PATTERNS OF COMMUNITY FACILITIES

Authors: Esther Hiu Kwan YUNG , Siqiang WANG

Abstract: Aging population has become a world-wide challenge for not only social services, but also the built environment of neighborhood. Community facility is a key element of built environment that has significant impact on elderly's daily lives. However, current planning and design guidelines mainly proposes the requirement of provision of community facilities and is lack of knowledge about older people’s needs, preferences, and use patterns of community facilities. Most relevant studies from western countries cannot be directly applied in the context of Asian cities due to their different urban densities, degrees of car dependence, and culture. This study aims to explore elderly’s needs and characteristics of use pattern of community facilities in local neighborhoods. In addition, this study also intends to identify the key influential factors of elderly’s use of community facilities. Six focus group meetings were conducted in Elderly Community Centers in Kwun Tong from Oct 2019 to Ja

Keywords: elderly, aging-in-place, community facility, urban renewal

Pages: 17 - 21 | DOI: 10.15224/978-1-63248-189-4-04

5. TEACHER'S INFLUENCE ON INDIVIDUAL'S POSTGRADUATE EDUCATIONAL ASPIRATIONS

Authors: Meechai Orsuwan

Abstract: This paper hypothesizes that positive attitude towards education can be nurtured and developed during the childhood period. Hence, the research employs longitudinal data to examine the impact of high school teacher characteristics on the postgraduate educational aspirations of their former students 12 years after they were first interviewed. The results indicate that individual's postgraduate educational aspirations are positively related to student's perceptions of their former high school teachers. Individuals who believe their teachers were good are likely to pursue postgraduate education

Keywords: aspiration, postgraduate, teacher

Pages: 22 - 25 | DOI: 10.15224/978-1-63248-189-4-05

6. INTERRACIAL INTERACTION AND SOCIAL SELF-COINTERRACIAL INTERACTION AND SOCIAL SELF-CONCEPTNCEPT

Authors: Meechai Orsuwan

Abstract: This study examines the impact of interracial interactions on student's social self-concept across racial/ethnic groups four years after they enter college. Our study finds significant changes in the social self-concepts of White, Native American, African American, Latino/a, and Asian American students from 1999, when they entered college, to 2003. As expected, the social self-concepts of students who engage in interracial interactions tend to improve over time

Keywords: interracial interaction, social self-concept

Pages: 26 - 28 | DOI: 10.15224/978-1-63248-189-4-06

7. INFRARED BURNER WITH INCREASED FIRING RATE AND HIGH SURFACE TEMPERATURE

Authors: NIKOLAY VASILIK

Abstract: Experiments and computations were conducted on infrared radiant burner operated on natural gas/air mixtures. The burner had not porous media and consisted of plates (recuperative elements) of heat-resistant metal alloy (Fe base, Cr 25%, Al 6%) with high thermal conductivity. The height of the recuperative elements system varied from 18 mm to 70 mm. The Al2O3 coatings were tested and found effective for covering the surface of the recuperative elements in burners. The operating surface temperature of recuperative elements coated with aluminum oxide reached values of 1450°C. Stable combustion mode is implemented in the range of specific burning power (firing rate) values from 2.8 MW/m2 to 5.3 MW/m2 per unit area of the gas stream cross-section. The maximum power of the burner is 16 kW with a flow cross-section of 30 cm2. The concentration of nitrogen oxides in the combustion products is up to 14ppm, the concentration of carbon monoxide is up to 20 ppm with an excess air coefficient (air

Keywords: infrared burner, natural gas, recuperative element, coating, surface combustion, firing rate, surface temperature, emissons

Pages: 29 - 34 | DOI: 10.15224/978-1-63248-189-4-07

8. INFLUENCE OF TRAIN SPEED ON THE DYNAMIC BEHAVIOR OF THE BRIDGE-TRAIN SYSTEM

Authors: Francois Alfred MESSI , Lezin SEBA MINSILI , Steeve Arnauld EVINA

Abstract: The need to find a sustainable method easily understood and applied by a common construction engineer in less technically advanced countries compels us to start the work presented in this paper as a pushover method in bridge-vehicle interaction research. Handling limited scientific resources to solve complex structural engineering problems to predict and control the traffic induced vibration associated with high order differential equations is the main objective of this work. The proposed methodology models the bridge-vehicle system by considering the bridge sub model and the vehicle sub model in the system interaction model, each subsystem including interaction dynamic parametric elements associated with irregularities on the wheel-rail interface, and the resulted dynamic interaction equations are solved using higher-order and fixed-point methods. Graphical results obtained from the developed numerical approximation is easily applied and understood by local civil engineers with adequa

Keywords: dynamic, bridge deck, vehicle, sub model, interface, wheel-rail, Interaction.

Pages: 35 - 41 | DOI: 10.15224/978-1-63248-189-4-08

9. A SIMPLE SEQUENTIAL DATA PROTOCOL FOR IOT APPLICATIONS

Authors: Dejana Herceg , Ivan Petkovi , Herceg

Abstract: We present a simple sequential data protocol (SSDP) - an implementation of a lightweight message encoding and exchange protocol for Arduino-based sensor devices. The protocol supports simple data types, strings and binary arrays with low overhead. It defines several types of messages used to discover device metadata, send and receive sensor reading values and runtime parameter values, as well as alarms. The SSDP Arduino library is simple and has a low memory footprint. In conjunction with mesh networking, SSDP can be used to quickly and efficiently build sensor networks based on inexpensive Arduino hardware.

Keywords: sensor networks, Arduino, microcontroller, protocol, message exchange, IoT

Pages: 50 - 54 | DOI: 10.15224/978-1-63248-189-4-10

10. APLICATION OF A BUILDING DYNAMIC SIMULATION IN THE DEVELOPMENT OF HORIZONTAL SHADING DEVICE PASSIVE SOLUTION IN AN UNIVERSITY CANTEEN

Authors: Eusébio Z. E. Conceição , Hazim B. Awbi

Abstract: In this work the application of a building dynamic simulation in the development of horizontal shading device passive solution applied in an university canteen is studied. The building dynamic simulation, that simulates simultaneously buildings or groups of buildings, with complex topologies, in transient conditions, considers the solar radiation, the HVAC system, glass radiative proprieties, radiative heat exchanges, thermal solutions, occupants’ comfort and air quality, and others. In the horizontal shading devices passive solutions the numerical model, using a sun trajectory and window position, developed efficient external shading devices. The canteen considers three levels and is divided in 37 spaces. In the simulation, 100 transparent surfaces and 773 opaque surfaces are considered. Special attention is given in the students’ main canteen, professors’ main canteen and university bar. The simulation is made in summer conditions. A simulation without and with horizontal shadi

Keywords: Building simulation; Solar; Energy, Thermal comfort; Indoor air quality

Pages: 55 - 60 | DOI: 10.15224/978-1-63248-189-4-11

11. NUMERICAL STUDY OF A SURFACE CONFLUENT JETS VENTILATION SYSTEM APPLIED ON A VIRTUAL OCCUPIED CHAMBER

Authors: Eusébio Z. E. Conceição , Hazim B. Awbi

Abstract: The purpose of this numerical study is to evaluate the thermal comfort and indoor air quality provided by a surface confluent jets ventilation system applied on a virtual occupied chamber. This numerical study is carried out using a coupling of an integral numerical model, that simulates human thermal response systems, and differential numerical model, that simulates the computer fluid dynamics. The Draught Risk around the occupants, thermal comfort, indoor air quality and Air Distribution Index (ADI) are evaluated. The study was performed for winter and summer typical conditions. The results show that the surface confluent jet system presents, in general, an acceptable thermal comfort level and an acceptable indoor air quality, with carbon dioxide concentration values below the limit of 1800 mg/m3. The ADI value is better in winter than in summer conditions

Keywords: numerical simulation, confluent jets, thermal comfort, indoor air quality, draugt risk

Pages: 61 - 67 | DOI: 10.15224/978-1-63248-189-4-12

12. NUMERICAL SIMULATION OF UNDERGROUND THERMAL ENERGY STORAGE APPLICATION IN UNIVERSITARY BUILDINGS IN SUMMER CONDITIONS

Authors: Eusébio Z. E. Conceição , Hazim B. Awbi

Abstract: In this numerical simulation the Building Dynamic Software is used in an application of underground thermal energy storage in a university building with complex topology. The numerical simulation is made in summer conditions with mediterranean environment. In this numerical simulation, the passive and active solar strategies are considered. Building Dynamic Software calculates the air temperature of the spaces, the surface temperature of opaque bodies, transparent bodies and internal bodies, the mass of contaminants and water inside the spaces and in the surfaces, the thermal comfort and air quality and the energy transport and consumption. The university building is divided into 319 spaces, distributed by four floors, and is composed by 329 transparent surfaces (windows) and 3585 opaque surfaces (internal and external walls, doors, and others). Below the ground floor is considered, numerically, an underground floor, with the same area of the building and with a typical floor height, u

Keywords: Building Dymamic Software; Undeground Space; Thermal Energy Storage; Thermal Comfort, Indoor air quality.

Pages: 68 - 72 | DOI: 10.15224/978-1-63248-189-4-13

13. CRITICAL IMPLEMENTATION FACTORS FOR CLOUD-BASED ENTERPRISE RESOURCE PLANNING IN THE NIGERIAN MARITIME LOGISTICS CHAIN

Authors: Kuranga Akeem Sulaiman , Maslin Masrom , Nurazean Maarop

Abstract: Recent research and practice have shown that cloud-based ERP systems if implemented correctly can be beneficial to the maritime logistics and supply chain process. It allows the entire Maritime Industry to share and analyze data across all divisions and help with the improvement of inefficient operations and processes in a large supply chain. Although a successful implementation comes with some challenges but the benefits are too strong to dispute. This study examined the critical success factor for the implementation of a Cloud-based Enterprise Resource Planning (CERP) in the Nigerian Maritime industry through a comprehensive review of the literature and a methodology involving interviews with managers and top executives in the Nigerian Maritime industry to extract their views. Empirical data were collected from 130 participants including top management and users involved in the Maritime industry through a survey questionnaire. The results of the survey and studies conducted establish

Keywords: Cloud-based Enterprise Resource Planning, Maritime Logistics Chain, Nigeria Maritime Industry

Pages: 42 - 49 | DOI: 10.15224/978-1-63248-189-4-09

14. A SIMPLE SEQUENTIAL DATA PROTOCOL FOR IOT APPLICATIONS

Authors: IVAN MAURITS , Dejana Herceg

Abstract: We present a simple sequential data protocol (SSDP) - an implementation of a lightweight message encoding and exchange protocol for Arduino-based sensor devices. The protocol supports simple data types, strings and binary arrays with low overhead. It defines several types of messages used to discover device metadata, send and receive sensor reading values and runtime parameter values, as well as alarms. The SSDP Arduino library is simple and has a low memory footprint. In conjunction with mesh networking, SSDP can be used to quickly and efficiently build sensor networks based on inexpensive Arduino hardware.

Keywords: sensor networks, Arduino, microcontroller

Pages: 50 - 54 | DOI: 10.15224/978-1-63248-189-4-10