Sharif Digital Repository

Cost and time overruns have been a common characteristic of development projects in many countries. This paper presents a theory of cost and time overruns based on project cost structure. The cost of a development project consists of base cost and progress cost. Base cost keeps a project ready for physical progress. Progress cost creates real physical progress on the project. This cost structure has an important inherent dynamic characteristic with implications for the efficiency and effectiveness of project management. An imbalance between annual budget and ongoing projects results in an increasing inefficiency and ineffectiveness unrelated to the quality of management of individual... 

The concept of smart grid (SG) has been introduced to improve the operation of the power systems. In modern structures of power systems, different reasons prompt researchers to suggest integrated analysis of multi-carrier energy systems. Considering synergy effects of the couplings between different energy carriers and utilising intelligent technologies for monitoring and controlling of energy flow may change energy system management in the future. In this paper, we propose a new solution which is entitled ‘smart energy hub’ (SEH) that models a multi-carrier energy system in a SG. SEH solutions allow homeowners to manage their energy consumption to reduce their electricity and gas bill. We... 

Purpose – This paper aims to provide a criteria-based evaluation framework for assessing knowledgemanagement system (KMS) development methodologies. Design/methodology/approach – The evaluation criteria have been elicited based on the features expected from a successful KMS. Furthermore, a number of prominent KMS development methodologies have been scrutinized based on the proposed evaluation framework. Findings – It was demonstrated that the proposed evaluation framework is detailed and comprehensive enough to reveal the strengths and weaknesses of KMS development methodologies. It was also revealed that even though the evaluated methodologies possess certain strong features, they suffer... 

This paper proposes a centralized optimization-based home energy management (HEM) scheme in a macro energy hub structure. An energy hub management system manages the aggregated load of a group of residential micro energy hubs to minimize the total load deviation. The operational characteristics of the household appliances and the threshold energy cost of the customers are incorporated in the propounded method to provide the customers' comfort. Numerical studies show the effectiveness of the proposed method performance  

Wireless sensor networks (WSNs) usually consist of many tiny sensor nodes and a Sink. Problems like nodes' misbehavior due to malicious, compromised or selfishness intentions, and WSNs' security vulnerabilities against different attacks due to free and unprotected communications, untrusted and broadcasted transmissions, hostile environments and limited resources, degrade the security and overall performance of WSNs. In another direction, most of the traditional security mechanisms are unsuitable for WSNs. One significant security solution against these problems is Trust Management System (TMS); TMS enhances the security by detecting the nodes' abnormal behaviors; it improves the cooperation... 

This paper presents an ITS project in Iran, as the first intelligent tunnel management system to be deployed in support of urban traffic management. It aims to protect highway users from possible hazards, provide them travel information and support traffic controllers in efficient and effective exercise of daily works. The project concerns a high trafficked tunnel which has been inaugurated in July 2006 to connect two parts of a highway in Tehran, linking the northwest districts to northeast ones. This corridor was selected as a good candidate, due in particular, to the variety of problems encountered [1]. In order to launch the project a co-operation has been negotiated in late 2005 between... 

Smart grids help local distribution companies (LDCs) facilitate the communication between grid operators and residential prosumers. While the prosumers are striving to optimize their daily load profile by home energy management systems (HEMSs) deployment, the LDCs attempt to enhance the operation of the grid in an efficient way and decrease network losses. This paper attempts to develop a new bi-level probabilistic optimization framework wherein an HEMS optimizes its respective daily load profile, and determines its flexibility provision, which is communicated to an LDC. In the proposed framework, a decentralized approach is used to achieve the flexibility product, which is the modulation of... 

This paper suggests several improvements over the original Time-expanded Decision Network (TDN; a powerful and generic methodology introduced by Silver and de Weck for designing evolvable complex systems) in order to leverage its ease, flexibility, and scope of use. A more accurate model of the switching process, a simpler network representation, and the ability to address systems with unknown lifetime are some of the improvements. However, the most important added feature is the ability to account for other design requirements within the process, which enables the designers to embed the TDN methodology into their general concept exploration phase. As a result, the enhanced TDN (ETDN)... 

New technologies such as smart homes and appliances and renewable energy production have been attracting much attention in recent years. In practice, the management of these technologies to get the minimum household payment has become a challenge due to the time-varying electricity price. In this paper, we propose a real time energy management system to manage the appliances and storages. The solar energy is charged in the storages and used together with the grid electricity to supply the appliances. The proposed management system uses an ILP-based Home Energy Management (ILPHEM) optimization engine. ILPHEM schedules appliances requests and storage usage based on updated real time input data... 

Regarding the increasing number of electrical devices in the smart homes that leads to increase in total electricity consumption and cost, it is essential to use energy management methods to reduce the electricity cost. However, this can cause resident's dissatisfaction. Hence, it is important to define a method in which cost and dissatisfaction be optimized simultaneously. Among different services, an electric vehicle is the one that can be used as an energy storage system, so it can reduce the daily cost despite of increasing the total energy consumption. In this paper, we study the effect of the EV on the cost and dissatisfaction in our proposed method. © 2018 IEEE  

Transitions is today’s debate in almost all topics both in academia and practice. Energy transitions among others, have received relatively more attention, due to the global demand for increasing energy efficiency and lowering environmental impacts. In recent decades, energy management systems, through implementing energy management programs and related practices within industrial companies, have played a vital role in enhancing industrial energy efficiency performance levels. However, still there are problems at very first step of energy management program installation, which is decision-making. Despite market and non-market failures, lack of information, inadequate knowledge, the... 

Energy use in buildings contributes a large part in global energy demand. To reduce energy use in this group of consumers, specially in cold seasons, an automatic control technique is proposed. In this paper, a model predictive controller (MPC) is employed to minimize the boiler activation time. The method uses the building model and incorporates the weather forecast data to act on the actuator in an optimal fashion while treating the user comfort constraints. This technique, as a part, can be embedded into the building energy management system. The building model parameters are obtained via an online identification process using unscented kalman filter (UKF). This identification is... 

This paper proposes a new energy management model for residential buildings to handle the uncertainties of demand and on-site PV generation. For this purpose, the building energy management system (BEMS) organizes a transactive energy (TE) market among plug-in electric vehicles (PEVs) to determine their charge/discharge scheduling. According to the proposed TE framework, the PEV owners get reimbursed by the BEMS for the flexibility they offer. In this regard, the PEV owners submit their response curves for reimbursement upon arrival. Then, the BEMS solves an optimization problem to maximize its own profit and determine the real-time TE market-clearing price. Afterward, based on the clearing... 

This article is focused on the application of 'Continuous Descent Approach' [CDA] to reduce the overall terminal traffic wastage of time and fuel consumption as well as reducing environmental emissions. This goal is achieved by introducing an online alternative CDA route under management of a heuristic optimization algorithm that minimizes the overall holding time. Performing a study on Atlanta international Hartsfield-Jackson airport, ATL, the results show considerable 60% decrease in cost function. Such achievement encourages the idea of implementing 'Dynamic CDA Routing Algorithm' [DCRA]  

Security is a critical and vital task in WSNs. Recently, key management as the core of a secure communication has received lots of attention, but in most of the proposed methods security has been compromised in favor of reducing energy consumption. Consequently, perfect resiliency has not been achieved by most of the previous works. Hostile environment, ability of adversary to capture the nodes, and dead nodes with sensitive data scattered in the region, calls for a more secure and yet practical method. This paper proposes a novel authentication scheme based on broadcast messages from BS to improve security of key management system. Through simulation it is shown that energy consumption of...