Symmetry properties of tetraammine platinum(II) with C_(2v) and C_(4v) point groups     

MOGHANI Ghorban Ali  ASHRAFI Ali Reza  HAMADANIAN Masood 《Journal of Zhejiang University. Science. B》2005,(3)

INTRODUCTION The simplicity and elegance of some of theapplications of graph theory to chemistry can perhapsonly be compared with the results from group theorydealing with symmetry as a basic quality of a system.In some problems connectivity and symmetry arecombined and the question of determining symmetryproperties of graph becomes important. Given here are some definitions and notations.An automorphism of a graph G is a permutation g ofthe vertex set of G with the property that, for an…  相似文献   

Angular region: a measure of underdamped behavior     

F.M. Reza 《Journal of The Franklin Institute》1982,314(3):191-202

The natural modes of an underdamped dynamical system are given by the characteristic numbers of the quadratic operator pencil where the operator A depends on the dissipative and reactive elements of the system, while B depends solely on the reactive elements. The operator P(s) for every applied stimulus vector signal x must satisfy: A measure of underdamped behaviour is suggested by predetermining an angular region |φ| containing all natural modes of the system, When a comparison between positive operators A and B is available, say B²=KA, then The paper is motivated by Duffin-Krein-Gohberg's earlier mathematical contributions.  相似文献   

The role of intellectuals in administrative development and social change in modern Iran     

Reza Arasteh 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1963,9(3):326-334

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Teacher-directed learning in view-independent face recognition with mixture of experts using single-view eigenspaces   总被引：1，自引：0，他引：1  

Reza Ebrahimpour  Ehsanollah Kabir 《Journal of The Franklin Institute》2008,345(2):87-101

We propose a new model for view-independent face recognition by multiview approach. We use the so-called “mixture of experts”, ME, in which, the problem space is divided into several subspaces for the experts, and the outputs of experts are combined by a gating network. In our model, instead of leaving the ME to partition the face space automatically, the ME is directed to adapt to a particular partitioning corresponding to predetermined views. To force an expert towards a specific view of face, in the representation layer, we provide each expert with its own eigenspace computed from the faces in the corresponding view. Furthermore, we use teacher-directed learning, TDL, in a way that according to the pose of the input training sample, only the weights of the corresponding expert are updated. The experimental results support our claim that directing the experts to a predetermined partitioning of face space improves the performance of the conventional ME for view-independent face recognition. In particular, for 1200 images of unseen intermediate views of faces from 20 subjects, the ME with single-view eigenspaces yields the average recognition rate of 80.51% in 10 trials, which is noticeably increased to 90.29% by applying the TDL method.  相似文献   

Characterization and Classification of Mesenchymal Stem Cells in Several Species Using Surface Markers for Cell Therapy Purposes     

Hori Ghaneialvar  Leila Soltani  Hamid Reza Rahmani  Abbas Sahebghadam Lotfi  Masoud Soleimani 《Indian journal of clinical biochemistry : IJCB》2018,33(1):46-52

Mesenchymal stem cells are multipotent cells capable of replicating as undifferentiated cells, and have the potential of differentiating into mesenchymal tissue lineages such as osteocytes, adipocytes and chondrocytes. Such lineages can then be used in cell therapy. The aim of present study was to characterize bone marrow derived mesenchymal stem cells in four different species, including: sheep, goat, human and mouse. Human bone-marrow mesenchymal stem cells were purchased, those of sheep and goat were isolated from fetal bone marrow, and those of mouse were collected by washing bone cavity of femur and tibia with DMEM/F12. Using flow-cytometry, they were characterized by CD surface antigens. Furthermore, cells of third passage were examined for their osteogenic and adipogenic differentiation potential by oil red and alizarin red staining respectively. According to the results, CD markers studied in the four groups of mesenchymal stem cells showed a different expression. Goat and sheep expressed CD44 and CD166, and weakly expressed CD34, CD45, CD105 and CD90. Similarly, human and mouse mesenchymal cells expressed CD44, CD166, CD105 and CD90 whereas the expression of CD34 and CD45 was negative. In conclusion, although all mesenchymal stem cells display plastic adherence and tri-lineage differentiation, not all express the same panel of surface antigens described for human mesenchymal stem cells. Additional panel of CD markers are necessary to characterize regenerative potential and possible application of these stem cells in regenerative medicine and implantology.  相似文献   

Convexity of the Energy Domain     

F.M. Reza 《Journal of The Franklin Institute》1983,315(3):179-194

A basic theorem describing the convexity of the energy domain for the general family of linear time-invariant (active or passive, reciprocal or non-reciprocal, lumped or distributed, single variable or multivariable) physical system {T} is proved.Theorem: Let F = P + jQ represent the complex energy associated with any linear physical system T (n-port). For any specified excitation of frequency s and the family of constant energy content input signals {i:∥i∥= constant}, the point F describes a convex domain in the {P;Q} plane.Part I contains a mathematical and a network theoretic proof of the foregoing theorem. In Part II the geometric nature of the energy loci for the two-ports is examined. It is shown that for all two-ports with double eigenvalves the energy domain is circular. For two-ports with distinct eigenvalves, the convex energy domain is an ellipse. The geometric characterization of this elliptic domain is examined and examples verified by computer.The concept of convexity is frequently exploited in optimization of energy in electric power system and quadratic cost functions in control theory. In this respect the central theorem of this paper, its proof and geometric ramifications should prove to be of basic interest for all linear systems.  相似文献   

Israeli public diplomacy toward the United States: a network and narrative approach     

Fatemeh Shafiee Sarvestani  Saied Reza Ameli  Foad Izadi 《亚洲交流杂志》2019,29(2):181-200

Israel’s public diplomacy efforts in the U.S. are aimed at garnering American public support for Israeli foreign policy. This study aims to identify the networks of Israeli public diplomacy toward the United States. Using the theoretical frameworks of networked public diplomacy and strategic narrative, the authors try to understand how network strategy is used and information is circulated to create a strategic narrative. Therefore, the two methods of social network analysis and qualitative content analysis are applied to identify the networks of Israeli public diplomacy in the United States and the content produced by it. The study finds that in Israel’s public diplomacy model, the networking method stands in contrast to its government-oriented strategic narrative. Thus, new forms of communication are applied to conduct old strategies. The research identifies four types of actors who apply new public diplomacy techniques and dissects the strategic narrative they employ to affect the American public in the service of Israeli interests. Despite the effort to apply new forms of public diplomacy, strategic narrative production and dissemination remain highly governmental and closed, which is indicative of the persistence of old forms of public diplomacy.  相似文献   

Implementing vertical and horizontal engineering students’ integration and assessment of consequence academic achievement     

Sarim Al-Zubaidy  Reza Dashtpour 《European Journal of Engineering Education》2012,37(4):383-396

Recent scholarship references indicate that integration of the student body can result in an enhanced learning experience for students and also greater satisfaction. This paper reports the results of a case study whereby mechanical engineering students studying at a newly established branch campus in Dubai of a British university were exposed to vertical and horizontal integration. Different activities have been embedded to ensure that students integrated and worked together with their peers and colleagues at different levels. The implemented processes and practices led to improved academic achievements, which were better than those of a similar cohort of students where no effort had been made to integrate. The analysis revealed that cooperative learning and the degree of academic support provided by teachers are positively and directly correlated with academic as well as the students’ own sense of personal achievement. The results are discussed in light of previous research and with reference to the cultural context of the study.  相似文献   

Barriers of the development of web-based training in agricultural higher education system in Iran: A case study of Hamadan Bu Ali Sina University,Iran     

Heshmatollah?SaadiEmail author  Khalil?Mirzayi  Reza?Movahedi 《Education and Information Technologies》2016,21(1):53-70

Recently, higher education systems seek to use network-based and Internet-based information technologies in education, teaching and learning. E-learning in Iran higher education system has been started since 2003, however, its development has been very slow. The present study is a survey research. The participants of the study are faculty members, graduates and PhD students in Agriculture in Bu Ali Sina University. Total number of participants were analyzed (n?=?500). The accuracy of indicators and items in the questionnaire (face validity) has been confirmed by specialists. A questionnaire was used to collect data. Reliability was calculated by using Cronbach Alpha. In this study, Factor analysis is used to achieve the key factors. The results show that deficiency of executives, lack of learners’ motivation, infrastructural barriers, restriction of credit, and software and hardware limitations are the main problems in the development of web-based training. At the end of the article, some recommendations are presented aiming to accelerate electronic training in Iran’s higher education system.  相似文献   

Defending recommender systems by influence analysis     

Mohammad Amin Morid  Mehdi Shajari  Ali Reza Hashemi 《Information Retrieval》2014,17(2):137-152

Collaborative filtering (CF) is a popular method for personalizing product recommendations for e-commerce applications. In order to recommend a product to a user and predict that user’s preference, CF utilizes product evaluation ratings of like-minded users. The process of finding like-minded users forms a social network among all users and each link between two users represents an implicit connection between them. Users having more connections with others are the most influential users. Attacking recommender systems is a new issue for these systems. Here, an attacker tries to manipulate a recommender system in order to change the recommendation output according to her wish. If an attacker succeeds, her profile is used over and over again by the recommender system, making her an influential user. In this study, we applied the established attack detection methods to the influential users, instead of the whole user set, to improve their attack detection performance. Experiments were conducted using the same settings previously used to test the established methods. The results showed that the proposed influence-based method had better detection performance and improved the stability of a recommender system for most attack scenarios. It performed considerably better than established detection methods for attacks that inserted low numbers of attack profiles (20–25 %).  相似文献