Abstract.The harmonic index of a graph G is defined as the sum of the weights of all edges uv of G, where d(u) denotes the degree of a vertex u in G. In this work, we present the minimum and maximum values of the harmonic index for connected graphs with girth at least k (), and characterize the corresponding extremal graphs. Using this result, we obtain several relations between the harmonic index and the girth of a graph. Read the pdf.
Andrei ALEXANDRU, Gabriel CIOBANU
Abstract. We present a new semantics of the πI-calculus, namely the nominal semantics. A set of compact transition rules is given in terms of nominal logic by using a specific nominal quantifier. Based on several nominal techniques, it is proved an equivalence between the new nominal semantics and the original semantics of the πI-calculus, emphasizing the benefits of presenting the transition rules by using the nominal techniques. Read the pdf.
Hitendra GARG, Suneeta AGARWAL
Abstract. The proposed watermarking algorithm is based on geometrical properties of 3D mesh. The vertices of 3D mesh surface are categorized into flat, peak and deeper region. We first compare the perceivable distortion due to watermark insertion in the vertices of deep surfaces and the vertices belonging to either flat or peak surfaces. Our comparative analysis shows that insertion of watermark in deeper surface have less distortion in comparison to watermark insertion in flat and peak surfaces. In view of the fact, these vertices are categorized into three mutually exclusive groups. The first group (S1) is composed by the vertices of deeper area. For obtaining the vertices of second group (S2), the vertex normal is represented in IEEE-754 representation and nth bit of mantissa is considered as ‘1’. The third set (S3) contains the remaining vertices. The
Mugurel Ionuţ ANDREICA, Nicolae ŢĂPUŞ
Abstract. Answering nearest neighbor queries is an important problem in many areas, ranging from geographic systems to similarity searching in object data-bases (e.g. image and video databases). In order to answer such queries efficiently, an index data structure is usually constructed over the searched objects. In this paper we present novel top-down and bottom-up sequential algorithms for constructing a multidimensional quad-tree index. In all the algorithms the objects may be indexed in association with both quad-tree nodes which they intersect and those which they do not intersect. The common aspect of all the
Kan WU, Peng GONG, Jiantao WANG, Xiaopeng YAN, Ping LI
Abstract. The authenticated key agreement protocol is an important security protocol for the session initiation protocol, which allows the and the server to authenticate each other and generate a shared session key for privacy, integrity, and non-repudiation in their communications. Recently, Zhang et al. proposed a new authenticated key agreement protocol for the session initiation protocol using smart card and claimed their protocol was secure against various attacks. However, we found that Zhang et al.'s protocol cannot withstand the user impersonation attack, i. e., a malicious user could impersonate any other user to the server. We also propose a new authenticated key agreement protocol
Călin BÎRĂ, Lucian PETRICĂ, Radu HOBINCU
Abstract. The programming environment is often a key enabler of productivity and performance in any software development project. In a hardwaresoftware co-design scenario, the programming environment must easily adapt to changes in the parameters of the underlying hardware computation platform, and must be able to accurately measure the performance of the hardware in order to guide software development. In this paper we present OPINCAA, a framework for programming parallel accelerators which implement the ConnexArray architecture. OPINCAA provides a C++ syntax for accelerator software development, and the infrastructure for dispatching instructions to the accelerator.
Jianshu MAO, Bo ZHOU
Abstract. The sum-connectivity index of graph G is defined as the sum of the weights of the edges of G, where the weight of an edge uv of G is with dG(u) being the degree of vertex u in G. We determine the n-vertex trees with the fourth for , the fifth for , the sixth, and the seventh for maximum sum-connectivity indices, and the n-vertex trees with the fourth, the fifth, the sixth, and the seventh for , and the eighth for minimum sum-connectivity indices. Read the pdf.
Angel Martin DEL REY
Abstract. In this work, the reversibility problem for the elementary cellular automaton with rule number 150 is tackled. Although this problem was solved before, we will introduce in this work an alternative construction of the inverse cellular automaton by means of the transition matrices instead of transition dipolynomials. This new approach allows one to obtain a more efficient and effective algorithm to compute the inverse cellular automaton. Read the pdf.
Sunita BANSAL, Chittaranjan HOTA