http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/165 2026-05-19T18:58:11Z http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/310 A program anomaly intrusion detection scheme based on fuzzy inference Hoang, Dau Xuan; Nguyen, Minh Ngoc A major problem of existing anomaly intrusion detection approaches is that they tend to produce excessive false alarms. One reason for this is that the normal and abnormal behaviour of a monitored object can overlap or be very close to each other, which makes it difficult to define a clear boundary between the two. In this paper, we present a fuzzy-based scheme for program anomaly intrusion detection using system calls. Instead of using crisp conditions, or fixed thresholds, fuzzy sets are used to represent the parameter space of the program sequences of system calls. In addition, fuzzy rules are used to combine multiple parameters of each sequence, using fuzzy reasoning, in order to determine the sequence status. Experimental results showed that the proposed fuzzy-based detection scheme reduced false positive alarms by 48%, compared to the normal database scheme. 2008-01-01T00:00:00Z http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/309 Finding upper bounds of component instances with deallocation beyond local scope Hoang, A. Truong We develop an abstract component language and a static type system that can tells us the maximum resources a program may use. We prove that the upper resource bound is sharp and we point out a polynomial algorithm that can infer the sharp bound. Knowing the maximal resources a program may request allows us to adjust resource usage of the program and to prevent it from raising exceptions or behaving unexpectedly on systems that do not have enough resources. This work extends our previous works in one crucial point: the deallocation primitive can free an instance beyond its local scope. This semantics makes the language much closer to practical ones. 2008-01-01T00:00:00Z http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/307 Checking the conformability in CORBA component model specifications Tran, Thi Mai Thuong; Vo, Van Thanh; Truong, Ninh Thuan We proposed in this paper an approach for checking the conformability in CORBA component model specifications. In software engineering, it is demonstrated that discovering bugs in earlier phases is much more economical than later phases. We focused thus on verifying components by their ports specification. In order to do this, firstly we determined constraints on kinds of port as well as on types of port which the connection between ports must satisfy, and then formalized them to be able to prove automatically using formal prover tools. Here, we proposed to use the B method for verifying components in a CCM specification 2008-01-01T00:00:00Z http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/305 Conflicting chip firing games on graphs and on trees Pham, Tra An; Phan, Thi Ha Duong; Tran, Thi Thu Huong Chip Firing Games on (directed) graph are widely used in theoretical computer science and many other sciences. In this model, chips are fired from one vertex to all of its neighbors at the same time. The purpose of our paper is to study an extended version of this model, the Conflicting Chip Firing Game, by considering that chips can be fired from one vertex to one of its neighbors at each time. Our main results are obtained when the support graph of this game is a rooted tree. In this case, we give the characterization of its reachable configurations and of its fixed points. Moreover we show the local lattice structure of its configuration space 2008-01-01T00:00:00Z