Sharif Digital Repository

Planning is one of the most important branches of artificial intelligence. The goal of planning is automated production of sequence of actions (plans) for some specified tasks. However the computation done by planners is very time consuming and complicated. Distributing computation is one solution to overcome such difficulties. Distribution divides the load of process between a number of agents and increases robustness. The purpose of this project is to reduce the computational overhead of planning by the means of distributing the planning process between a numbers of planners. In the proposed method, we first divide a classical planning problem to two separate subproblems by decomposition... 

Two significant features of a transportation network, uncertainty and complexity, might cause some irregular behaviors. One example of such behaviors is chaotic flow in which the transportation system fails to reach equilibrium and people experience different daily travel times. These uncertainties are not controllable in any transportation system and, if not taken into consideration, will result to low levels of service and poor reliability. In this study, an evolutionary traffic assignmet model is used to illustrate when the network reaches bifurcation and chaos. Later, the effects of uncertainty in the parameters of supply and demand is tested on the evolutionary traffic assignment model.... 

Self-leadership” is a process through which individuals control their performance and lead themselves by using specific behavioral and cognitive strategies (Manz, 1986; Manz and Neck, 2004). This concept includes a toolkit of behavioral activities borrowed from social cognitive theory and goal setting. It also includes constructive thought processes that have been extensively studied in sports psychology. Scholars have categorized the SL (self-leadership) strategies into three main categories; behavioral, natural reward and constructive thought Strategies. (Neck and Houghton, 2006) Given the growing importance of self-leadership in contemporary organizations operating in an increasingly... 

Different molybdenum oxide nano/micro structure thin films were synthesized by thermal evaporation method under various growth conditions such as deposition time, temperature and evaporation source-substrate distance. Molybdenum oxide nanostructures grown on Si(100) such as nanowalls, nanostars and nanowires were characterized with scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), atomic force microscopy (AFM) and high resolution transmission electron microscopy (HRTEM). Shape and type of nanostructures were determined with SEM, AFM and HRTEM analysis. XPS analysis showed that the synthesized nanostructures contained Mo6+, Mo5+, Mo4+ and... 

Mankind with it’s finite resources (Time, Energy, …) cannot make use of every accessible option in daily activities (such as buying items, listening to music and reading news), and is restricted to decide on a handful of them. Available options are increasing on a daily basis and these surplus of available options had an adverse effect; Thus, leading us to more baffling situations. As a result, need for external assistance appeared in decision situations. Considering exceptional computation power available to computers, a framework named Recommender Systems were developed. Recommender systems try to use their accessible data in order to make fitting suggestions to users. Personalization and... 

Considering the extensive developments achieved up to now in the fields of trade and international transportation, as well as the key role of the freight transportation in the economical development of a zone or a country, the present research, titled “A Study of the Trade and Transportation Trends”, was planned. The available data concerning the trade of six types of the goods according to The United Nations Classification (SITC), within the period 1965-2005, have been analyzed in this research. The study has been focused on the Asian Multimodal Network constituted of 31 countries. Trading centre of each country in the selected network is assumed to be located in its capital town. The... 

The liquid breakup analysis and spray characteristics measurement of atomizer are very essential for the numerical modeling of the primary atomization in combustion chambers. The atomization process is irregular and random nature and is a chaotic phenomenon. This study was motivated by the lack of temporal analysis of the breakup process especially for the first and second wind-induced breakup regimes and the atomization regime. The aim of this study was to determine the location, velocity and structures of breakup liquid jet at different outlet pressures from 0.3 bar to 50 bar. The results indicate that the breakup length, ligament size, and the breakup time period are randomly varied in... 

Structures having buckling restrained braces (BRB) as earthquake resisting system, have the qualities of high lateral stiffness and the ability to damp the energy coming from earthquake, at the same time.In addition to new structures, these braces can also be used in rehabilitating old steel or concrete buildings. By using this kind of resisting system, smaller sections are needed in design of buildings and also the cost of repair after earthquake can be highly reduced.The most important advantage of buckling restrained braces is their equal behavior and capacity in both tention and compression, that causes high energy absorption as a result of symmetric and stable cyclic behavior. All these... 

Selecting a suitable material is crucial for repairing the old concrete structures and joining precast panels of bridges, especially the bond strength between the substrate concrete and the overlay material. In this regard, this research focused on high-performance alkali-activated slag concrete (HPASC) as a new concrete used as an overlay on ordinary Portland cement concrete (OPCC) as a block of old concrete. Approximately four hundred bi-surface shear (BSS) tests were performed to evaluate the interface properties of OPCC and HPASC. HPASC specimens were designed with different NaOH molarity, silica fume (SF) content, steel fiber content, age of repair material, and proportion of grooved... 

Artificial intelligence is a field that has made another revolution in the Fourth Industrial Revolution and has become one of the most widely used emerging technologies in the present era. Further investigation of the trends in this field shows that it has shown increasing growth in recent years. Also, in the future, this trend will continue and fundamental changes will occur in societies. For this reason, countries must definitely pay the necessary and sufficient attention to this field in their growth and development path. To achieve this growth path, it is intended to evaluate the status of leading countries in the field of artificial intelligence using two key variables in technological... 

The cyclometalated platinum(II) complex [Pt(Me)(bhq)(2-vpy)], 2, in which bhq = benzo{h}quinolone, 2-vpy = 2-vinylpyridine, has been prepared by reaction of the cyclometalated complex [Pt(Me) bhq)(SMe2)], 1 with one equiv 2-vinylpyridine. The similar complex [Pt(p-tolyl)(ppy)(2-vpy)], 3 in which ppy = 2-phenyl pyridine, has been prepared from reaction of the platinum(II) complex cis-[Pt(p-MeC6H4)2(SMe2)2] with one equiv 2-phenylpyridine and one equiv 2-vinylpyridine. Reaction of 2 with one equiv Br2 in acetone gave the cyclometalated platinum(IV) complex [Pt(bhq)Me(Br)(NC5H4CHCH2Br)], 4. The structure of the complexes 1-3 were determined using NMR Spectroscopy. The crystal structure of 3... 

Mobile ad hoc networks (MANETs) are the dynamically reconfigurable wireless networks in which mobile nodes communicate with each other without the need for any fixed infrastructure. In these networks mobile nodes are free to move, therefore, network topology changes rapidly. These changes can lead to significant performance degradations in network protocols. To cope with this, a desired solution is to predict movements of mobile nodes. In this way, we can be prepared for changes. This thesis proposes two mobility prediction methods. In both methods, each node uses the information extracted from its own history of movements to predict its future location. Results obtained by applying two... 

The wellbore instability increases the cost of drilling operations due to problems such as pipe sticking and lost circulation, so it is important to find the optimal well path. In this research, building a one-dimensional geomechanical model is investigated, and then the wellbore stability during drilling in different layers is evaluated. The geomechanical model is constructed using available data (well log data, mud logging unit data, and drilling reports) in a study reservoir and the optimal well path is determined by the appropriate inclination and azimuth using the geomechanical properties of the field and the stress regime, taking into account the wellbore stability and shear failure...