Benny Raphael

Benny Raphael
Indian Institute of Technology Madras | IIT Madras · Department of Civil Engineering

About

127
Publications
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Publications

Publications (127)
Article
Existing studies on automated construction equipment monitoring have focused mainly on activity recognition rather than fault detection. This paper proposes a novel equipment activity recognition and fault detection framework called hybrid unsupervised and supervised machine learning (HUS-ML). HUS-ML first identifies normal operations and known fau...
Chapter
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Collaboration between key project stakeholders lies at the heart of the construction industry’s workflows. Perhaps more than any other industry, effective collaboration is essential for the success of a construction project. As the project stakeholders come together to deliver a project only to move on to the next project where a new set of stakeho...
Article
Full-text available
A robust monitoring system is essential for ensuring safety and reliability in automated construction. Activity recognition is one of the critical tasks in automated monitoring. Existing studies in this area have not fully exploited the potential for enhancing the performance of machine learning algorithms using domain knowledge, especially in prob...
Conference Paper
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Machine learning techniques have been successfully implemented for the identification of various construction activities using sensor data. However, there are very few studies on activity recognition in the automated construction of low-rise residential buildings. Automated construction is faster than conventional construction, with minimal human i...
Article
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Automation is the best solution for achieving high productivity and quality in the construction industry at reduced cost and time. The main objective of this study is to develop an economical automated construction system (ACS) for low-rise buildings. The incremental development of the construction system and the structural system through different...
Patent
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The fracture characteristics of any type of concrete can be determined using a suitable analytical model combined with inverse analysis. The inverse analysis procedure generally consists of iterative modus operandi, which fit experimental flexural test data to obtain the parameters that define the tensile stress-crack opening (σ-w) curves. The prob...
Article
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Large amount of data is obtained during bridge monitoring using sensors. Interpreting this data in order to obtain useful information about the condition of the bridge is not straight forward. This paper describes a case study of a railway bridge in India and explains how multi-dimensional visualization tools were used to extract relevant informati...
Conference Paper
Full-text available
Automated construction creates an intricate working environment involving workers and machines. The added complexity of automated construction demands a rigorous monitoring system compared to conventional construction. The first stage of developing such a monitoring system is the identification of construction operations. This paper discusses a met...
Article
Purpose: Construction firms keep minimal resources to maintain productive working capital. Hence, resources are constrained and have to be shared among multiple projects in an organization. Optimal allocation of resources is a key challenge in such situations. Several approaches and heuristics have been proposed for this task. The aim of this paper...
Conference Paper
Full-text available
Automated construction involves complex interactions between machines and humans. Unless all possible scenarios involving construction and equipment are carefully evaluated, it may lead to failure of the structure or may cause severe accidents. Hence monitoring of automated construction is very important and sensors should be deployed for obtaining...
Article
Purpose: The purpose of this paper is to develop a framework to optimize time, cost and quality in a multi-mode resource-constrained project scheduling environment. Design/methodology/approach: A case study approach identified the activity execution modes in building construction projects in India to support multi-mode resource-constrained project...
Conference Paper
Full-text available
On-site data collection during construction activities help in evaluating productivity rates and preparing more accurate schedules. One of the challenges here is in collecting data automatically such that activity start times and durations can be computed reliably. This paper proposes a methodology to infer construction activities that are being pe...
Article
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Construction companies execute many projects simultaneously. In such situations, the performance of one project may influence the others positively or negatively. Construction professionals face difficulties in managing multiple projects in limited resource situations. The purpose of this study is to identify the problems in multiproject scheduling...
Conference Paper
Full-text available
There is a large programme of metro-rail construction in India, upgrading public transportation systems to provide rapid transit to millions of people in major Indian cities. The scale of this development makes it important to innovate as improvements in design, construction and operations can have a significant impact on built asset sustainability...
Article
In hot humid climates, a major portion of air conditioning energy is used for dehumidification. In traditional centralized air conditioning systems, air is cooled below the dew point to remove the moisture. This process is energy intensive. Liquid desiccant dehumidification systems (LDDS) provide a promising alternative as they use low grade or fre...
Article
(http://www.nicmar.ac.in/journal.php?Pid=1&Cid=13&Jid=19&Mid=68&S=1) Quality is one of the most important parameters for project performance evaluation. It is not considered as important as time and cost in practice, which results in a half-hearted attempt to achieve quality at project sites. However, during the operational and maintenance period,...
Conference Paper
Full-text available
Companies keep minimal resources such as equipment, labor, and non-renewable materials to maintain productive working capital. This means that resources are constrained, and a multi-project environment adds further complexity since resources have to be shared among projects. Existing project management approaches such as critical path method (CPM),...
Article
(http://www.nicmar.ac.in/journal.php?Pid=1&Cid=13&Jid=19&Mid=68&S=1) Project resources such as labor, material, and equipment are kept minimal to maintain the efficient working capital. Therefore, the limited resources need to be planned and scheduled in such a way that the project performances are met with minimum and acceptable deviations. Resou...
Article
Full-text available
This paper presents a methodology to use structural responses to monitor the progress of construction processes. The methodology was implemented on a launching girder used for viaduct construction of a metro rail project. A strain-based wireless sensor network was used for data acquisition. Structural responses from the launching girder were used t...
Article
This paper aims to objectively evaluate the potential of light shelves to improve daylighting and visual comfort. This study consists of two parts. The first part is experimental and involves measurements taken on a scaled prototype. More than one million data points were collected using illuminance sensors installed on a test chamber. The data was...
Conference Paper
Full-text available
Several severe acute respiratory syndrome outbreaks in recent 15 years have highlighted the issue of short-range aerosol transmission between healthcare workers and the patients. Concerns about the ventilation system design in healthcare centres have become topical and important. To minimize the spread of contaminated air exhaled by patients within...
Conference Paper
Full-text available
The tensile fracture process in fibre reinforced concrete (FRC)can be characterized by a cohesive stress versus crack opening curve (σ-w). The Probabilistic Global Search Lausanne (PGSL) optimization algorithm is used in an inverse analysis procedure developed to use experimental data from three-point bending tests on steel fibre reinforced concret...
Article
A great challenge associated with urban growth is to design for energy efficient and healthy built environments. Exploiting the potential for natural ventilation in buildings might improve pedestrian comfort and lower cooling loads, particularly in warm and tropical climates. As a result, predicting wind behavior around naturally ventilated buildin...
Article
Full-text available
Transmission line towers are usually analyzed using linear elastic idealized truss models. Due to the assumptions used in the analysis, there are discrepancies between the actual results obtained from full-scale prototype testing and the analytical results. Therefore, design engineers are interested in assessing the actual stress levels in transmis...
Article
Wind behavior in urban areas is receiving increasing interest from city planners and architects. Computational fluid dynamics (CFD) simulations are often employed to assess wind behavior around buildings. However, the accuracy of CFD simulations is often unknown. Measurements can be used to help understand wind behavior around buildings more accura...
Article
Although Computational Fluid Dynamics (CFD) simulations are often used to assess wind conditions around buildings, the accuracy of such simulations is often unknown. This paper proposes a data-interpretation framework that uses multiple simulations in combination with measurement data to improve the accuracy of wind predictions. Multiple simulation...
Conference Paper
Launching Girder is an equipment extensively used in prefabricated segmental construction of viaducts. It is used to lift, assemble, post-tension and load the spans of bridges constructed using the incremental launching method. Currently, there is limited automation in the operation of launching girders worldwide. Construction efficiency can be imp...
Conference Paper
Full-text available
Launching Girder is an equipment extensively used in prefabricated segmental construction of viaducts. It is used to lift, assemble, post-tension and load the spans of bridges constructed using the incremental launching method. Currently, there is limited automation in the operation of launching girders worldwide. Construction efficiency can be imp...
Article
Full-text available
Warm climates pose challenges to building energy consumption and pedestrian comfort. Knowledge of the wind flow around buildings can help address these issues through improving natural ventilation, energy use, and outdoor thermal comfort. Computational fluid dynamics (CFD) simulations are widely used to predict wind flow around buildings, despite t...
Article
In healthcare centers, healthcare workers would not know if patients are infected or not until the infected person is diagnosed and moved to an isolation room; therefore, the effectiveness of ventilation systems in removing the exhaled infectious air in the consultation room becomes important. To prevent the transmission of exhaled air, two types o...
Article
Full-text available
Good prediction of the behavior of wind around buildings improves designs for natural ventilation in warm climates. However wind modeling is complex, predictions are often inaccurate due to the large uncertainties in parameter values. The goal of this work is to enhance wind prediction around buildings using measurements through implementing a mult...
Article
The inhaled air quality in the breathing zone is strongly influenced by flow interactions around occupants. Personalized ventilation (PV) aims to supply conditioned outdoor air directly to the occupants’ breathing zone and thus improves the inhaled air quality. In this research, a personalized exhaust (PE) system is developed, which has two local e...
Conference Paper
Full-text available
Most engineering designs involve evaluation of several performance criteria. Usually these criteria conflict with each other and identifying good compromise solutions is difficult. While multi-criteria optimization approaches, such as Pareto filtering, have been applied to this task, not much attention has been paid to the selection of a single bes...
Article
Computational fluid-dynamics (CFD) simulations have become an important tool for the assessment of airflow in urban areas. However, large discrepancies may appear when simulated predictions are compared with field measurements because of the complexity of airflow behaviour around buildings and difficulties in defining correct sets of parameter valu...
Article
Full-text available
In the context of airborne infection control, it is critical that the ventilation system is able to extract the contaminated exhaled air within the shortest possible time. In order to minimise the spread of contaminated air exhaled by occupants efficiently, a novel Personalized Ventilation (PV) - Personalized Exhaust (PE) system has been developed,...
Article
Users are increasingly expecting intelligent behavior from automated building systems. However, incorporating and integrating user preferences in an automatic control algorithm is a complex task. In most commercial systems, control is done through local search techniques such as Proportional Integral Derivative (PID) control. Multiple criteria cann...
Article
Full-text available
This article investigates the performance of three different types of personalized exhaust devices. A top-personalized exhaust, which is a round device just above the human head; a shoulder-personalized exhaust, which consists of two local exhaust devices installed at the chair just above shoulder level; and a chair-personalized exhaust, which is a...
Book
Engineering Informatics: Fundamentals of Computer-Aided Engineering, 2nd Edition provides the foundation knowledge of computing that is essential for all engineers. This knowledge is independent of hardware and software characteristics and thus, it is expected to remain valid throughout an engineering career. This Second Edition is enhanced with tr...
Conference Paper
Full-text available
The inhaled air quality in breathing zone is strongly influenced by flow interactions around the occupants. Research shows that the inhaled air quality can be improved when personalized ventilation is used and the Personalized Ventilation (PV) system combined Personalized Exhaust (PE) system is able to help control the transmission of exhaled conta...
Conference Paper
Full-text available
This paper focuses on urban environmental system identification. Wind-flow modeling is a challenging task because of simplifications of complex processes as well as geometry simplifications. Even a more detailed model may not be accurate because of uncertainties in parameter values. Measurement data can be employed in order to improve our understan...
Article
This paper discusses the issue of selecting the design solution that best accords with an articulated preference of multiple criteria with an acceptable performance band. The application of a newly developed multi-criteria decision-making tool called RR-PARETO2 is presented. An example of HVAC design is used to illustrate how solutions could be sel...
Article
Full-text available
In this study, a set of experiments were conducted in a hot and humid climate to evaluate subjects’ behavior in operating an individually controlled personalized ventilation (PV) system. The system was equipped with individual control of air flow rate. The effect of the control system on thermal comfort and the responses of subjects were studied. 4...
Conference Paper
Full-text available
Three different personalized exhaust (PE) devices were simulated, evaluated and compared numerically using computational fluid dynamics method: a chair-PE, which is at the upper part of a chair, just behind the human head; a top-PE, which is a round device above the human head; a shoulder-PE, which are two local exhaust devices installed at the cha...
Article
The ability to predict and develop organizational flexibility is important for firms to survive and prosper in volatile business environments. The aim of this study is to investigate the constituents of and the constructs for predicting organizational flexibility. The specific objectives are to ascertain the relative importance of different constit...
Article
Purpose – The purpose of this paper is to improve current design processes by proposing a new approach based on multi-criteria optimization of the designed asset. Management of design in construction projects is a complex task since it involves collaboration between professionals in multiple disciplines. Traditionally, designers work with a single...
Article
Due to increasing awareness of the importance of energy efficiency, daylighting features such as light shelves are becoming more and more popular. A light shelf is a horizontal or inclined projection with a high reflectivity meant to increase the depth of daylight penetration into a room. Currently, a light shelf is treated as a passive design elem...
Conference Paper
Design of building systems should consider trade-offs between conflicting objectives. Multi-criteria search and optimization techniques have been developed for this purpose and these have been successfully applied to many design tasks. One popular approach is Pareto optimization which generates a population of efficient solutions. However, it canno...
Technical Report
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Final project report of the project "Integrated Control of Indoor Environmental Quality"
Conference Paper
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This paper describes a set of experiments that were conducted to evaluate user acceptance of different control strategies in the domain of personalized ventilation. Personalized ventilation involves supplying treated fresh air closer to the breathing zone and has the potential to maintain a healthier environment closer to the occupied zone. Two con...
Data
Many studies have suggested that Information Technology resources do offer strategic advantages to organisations and enhance their competitiveness through efficient and cost effective delivery of the organisations’ value chains. However, because most of these studies were carried out through imprecise and unstructured theoretical constructs the emp...
Conference Paper
Full-text available
This study aims to evaluate the energy savings of personalized ventilation (PV) when users are allowed to regulate the air flow themselves. A series of experiments involving human subjects were conducted in which different combinations of ambient temperatures and PV air temperatures were maintained. Altogether thirty sessions were conducted and fiv...
Conference Paper
Full-text available
This paper reports on a set of experiments conducted to evaluate user acceptance and occupant comfort of a Personalized Ventilation (PV) control system. Two different control strategies were tested, namely, manual and automatic. Altogether 10 experimental sessions of two hour durations were conducted. Each session involved about 36 subjects. Differ...
Article
Flexibility has been touted as an important requirement for firms to survive and prosper in turbulent and volatile economic environments. The aim of this research is to investigate the relevance of organizational flexibility management to construction firms, because firms that are more flexible are more likely to survive and prosper than less flexi...
Article
Full-text available
Despite several studies suggesting the strategic and competitive advantages that organisations could gain through Information Technology (IT)-enabled strategies; there is no precisely defined model for evaluating IT business value (ITBV). Attempts to quantify ITBV have led to inconsistencies and paradoxes. Some of these equivocal results are attrib...
Article
Full-text available
System identification using multiple-model strategies may involve thousands of models with several parameters. However, only a few models are close to the correct model. A key task involves finding which parameters are important for explaining candidate models. The application of feature selection to system identification is studied in this paper....
Data
Full-text available
The strategic impacts of Information Technology (IT) on the organisations' performance have been of interest to both managers and researchers for decades. This is partly because despite the massive investments in IT the findings on its contribution to organisation performance were inconsistent. Attempts to explain the reasons for the equivocal resu...
Conference Paper
Automated control of building systems is gaining increasing attention due to rising energy costs and enhanced environmental consciousness. Automated window blinds have the potential to save energy through striking a balance between daylighting levels and air conditioning load. Currently, most control systems for window blinds operate by setting a l...
Conference Paper
Full-text available
The idea that information technology (IT) resources can be used by organisations to gain competitive advantage has been around for over two decades. However, most of the concepts related to competitive advantages of IT are imprecise, unstructured and are not directly applicable to the construction industry. Furthermore, a major part of the literatu...