PCA in ERP environment using the misuse detection system design and implementation of RBAC permissions

Due to further development of the Network and Information Processing Systems, many information accesses may be allowed via a login process. In order to control those accesses, there exist some control instructions within the network traffics. However, it has a weak point that someone can steal a user’s account details and access the information based on the authority that has been given to the user. It looks that the access controls work but the information that is accessed by a user may also be abused. We collected many RBAC traffics that are generated in the RBAC access control system, which is then analysed to find out and formulate any connections to a user’s information access. Using the outcomes from the above, we propose a system in this paper that should be able to detect any user accesses with a high probability of accessing information illegally.     

A page‐shift transformation format of ISO 10646

ISO 10646 Universal Character Set (UCS) or Unicode covers symbols in most of the World's written languages. There are various UCS transformation formats (UTF). UTF‐8 is compatible with systems that assume 8‐bit characters. One of the problems with UTF‐8 is its space efficiency. For files containing most Asian characters such as Han ideographs, the file sizes increase by about 50% by using UTF‐8. Although the Standard Compression Scheme for Unicode (SCSU) can compress Unicode strings to the size of a locale‐specific character set, it is complicated and is not intended to serve as a general purpose interchange format. This paper proposes a page‐shift transformation format of ISO 10646, called UTF‐S. There are four pages: 1‐byte, 2‐byte, 3‐byte and 4‐byte. Shift to page 0 uses a special code ; shift to page 1, 2, and 3 uses ISO 2022 shift codes SO, SS2, and SS3, respectively. We test several text files and compare these UTF with Big5, a locale‐specific character set. The result shows that the space efficiency of UTF‐S is better than that of UTF‐16 and UTF‐8 and is close to that of SCSU. UTF‐S is suitable for replacing locale‐specific character sets with ISO 10646 in Internet applications, such as the World Wide Web. Copyright © 2001 John Wiley & Sons, Ltd.     

Bounds for nonpreemptive scheduling of jobs with similar processing times on multiprocessor systems using the LPT-Algorithm

The well-known, NP-complete problem of scheduling a set ofn independent jobs nonpreemptively onm identical parallel processors to minimize the maximum finish time is considered. Let ω₀ be the finish time of an optimal schedule and ω the finish time of a schedule found by the Longest Processing Time (LPT-)heuristic. We will improve the Graham-bound for the LPT-heuristic (ω/ω₀ ≤ 4/3 ? 1/3m) which is tight in general, by considering only jobs with similar processing times.     

Performance of CPU/GPU compiler directives on ISO/TTI kernels

GPUs are slowly becoming ubiquitous devices in High Performance Computing, as their capabilities to enhance the performance per watt of compute intensive algorithms as compared to multicore CPUs have been identified. The primary shortcoming of a GPU is usability, since vendor specific APIs are quite different from existing programming languages, and it requires a substantial knowledge of the device and programming interface to optimize applications. Hence, lately a growing number of higher level programming models are targeting GPUs to alleviate this problem. The ultimate goal for a high-level model is to expose an easy-to-use interface for the user to offload compute intensive portions of code (kernels) to the GPU, and tune the code according to the target accelerator to maximize overall performance with a reduced development effort. In this paper, we share our experiences of three of the notable high-level directive based GPU programming models—PGI, CAPS and OpenACC (from CAPS and PGI) on an Nvidia M2090 GPU. We analyze their performance and programmability against Isotropic (ISO)/Tilted Transversely Isotropic (TTI) finite difference kernels, which are primary components in the Reverse Time Migration (RTM) application used by oil and gas exploration for seismic imaging of the sub-surface. When ported to a single GPU using the mentioned directives, we observe an average 1.5–1.8x improvement in performance for both ISO and TTI kernels, when compared with optimized multi-threaded CPU implementations using OpenMP.     

Character representation

This paper describes ISO standard character sets currently in use, the use of SGML entity sets, and the TEI writing system declaration.Harry Gaylord is a senior lecturer in the Department of Humanities Computing at Groningen University, Groningen, The Netherlands. He is Chair of the SC 18 committee of the Dutch Standards Institute (NNI), and member of ISO SC 2 (Coded Character Sets) and ISO SC 18/WG8 (Document Processing and Related Communication). He is the author ofTEI TR1 W4 Character Entities and Public Entity Sets and co-author with John Esling of Computer Codes for Phonetic Symbols,Journal of the International Phonetic Association (1993), 23, 2, 85–97.The Chair of our technical committee submitted a draft of this article. Comments were received from David Birnbaum, Bert Bos, Steve DeRose, Berend Dijk, and Michael Sperberg-McQueen for which we thank them. The committee made revisions before submitting the final version to the editors of this issue of CHUM. In recognition of longstanding contributions to our work, the committee has elected the above mentioned contributors as honourable members, which increases our numbers five-fold. We also wish to thank the secretary general of ISO, L.D. Eicher, for permission to publish portions of the ISO standards and Jan van den Beld, secretary general of ECMA, for furnishing a complete copy of its official register of all known character sets and current versions of the ECMA standards. We also thank Edwin Smura, registrar of AFII, for supplying a copy of much of their font registry.     

Labeling source code with information retrieval methods: an empirical study

To support program comprehension, software artifacts can be labeled—for example within software visualization tools—with a set of representative words, hereby referred to as labels. Such labels can be obtained using various approaches, including Information Retrieval (IR) methods or other simple heuristics. They provide a bird-eye’s view of the source code, allowing developers to look over software components fast and make more informed decisions on which parts of the source code they need to analyze in detail. However, few empirical studies have been conducted to verify whether the extracted labels make sense to software developers. This paper investigates (i) to what extent various IR techniques and other simple heuristics overlap with (and differ from) labeling performed by humans; (ii) what kinds of source code terms do humans use when labeling software artifacts; and (iii) what factors—in particular what characteristics of the artifacts to be labeled—influence the performance of automatic labeling techniques. We conducted two experiments in which we asked a group of students (38 in total) to label 20 classes from two Java software systems, JHotDraw and eXVantage. Then, we analyzed to what extent the words identified with an automated technique—including Vector Space Models, Latent Semantic Indexing (LSI), latent Dirichlet allocation (LDA), as well as customized heuristics extracting words from specific source code elements—overlap with those identified by humans. Results indicate that, in most cases, simpler automatic labeling techniques—based on the use of words extracted from class and method names as well as from class comments—better reflect human-based labeling. Indeed, clustering-based approaches (LSI and LDA) are more worthwhile to be used for source code artifacts having a high verbosity, as well as for artifacts requiring more effort to be manually labeled. The obtained results help to define guidelines on how to build effective automatic labeling techniques, and provide some insights on the actual usefulness of automatic labeling techniques during program comprehension tasks.     

3DyRM: a dynamic roofline model including memory latency information

Modern systems present complex memory hierarchies and heterogeneity among cores and processors. As a consequence, efficient programming is challenging. An easy-to-understand performance model, offering guidelines and information about the behaviour of a code, may be useful to alleviate these issues. In this paper, we present two extensions of the well-known Berkeley Roofline Model. The first of these extensions, the Dynamic Roofline Model (DyRM), takes into consideration the complexities of multicore and heterogeneous systems, offering a more detailed view of the evolution of the execution of a code. The second, the 3DyRM, also adds information about the latency of memory accesses to better represent the behaviour on systems with complex memory hierarchies. A set of tools to obtain and represent the models has been implemented. These tools obtain the needed data from hardware counters, with low overhead. Different views are displayed by the tool that can be used to extract the main features of the code. Results of studying, with these tools, the NAS Parallel Benchmarks for OpenMP on two different systems are presented.     

High performance Prolog on a RISC

This paper presents some benchmark timings from an optimising Prolog compiler using global analysis for a RISC workstation, the MIPS R2030. These results are extremely promising. For example, the infamous naive reverse benchmark runs at 2 mega LIPS. We compare these timings with those for other Prolog implementations running on the same workstation and with published timings for the KCM, a recent piece of special purpose Prolog hardware. The comparison suggests that global analysis is a fruitful source of information for an optimising Prolog compiler and that the performance of special purpose Prolog hardware can be at least matched by the code from a compiler using such information. We include some analysis of the sources of the improvement global analysis yields. An overview of the compiler is given and some implementation issues are discussed. This paper is an extended version of Ref. 15)     

Knowledge information processing language: ShapeUp

A new logic programming language, ShapeUp, is developed. ShapeUp is an expanded Prolog system with string matching facilities. The language has been developed to give programmers a new computer programming environment, especially for knowledge information processing. This area includes natural language comprehension and intelligent text processing systems with better man-machine interfaces. For this kind of application, character string data play a principal part rather than conventional numerical data. In ShapeUp, string patterns are introduced as Prolog ‘terms’. Their matching process is performed inside the unification. Thus, a program is far simpler and easier to write and read in ShapeUp, than in conventional Prolog systems, and program size is extremely reduced.     

CARMEL-2: A second generation VLSI architecture for Flat Concurrent Prolog

CARMEL-2 is a high performance VLSI uniprocessor, tuned forFlat Concurrent Prolog (FCP). CARMEL-2 shows almost 5-fold speedup over its predecessor, CARMEL-1, and it achieves 2,400 KLIPS executingappend. This high execution rate was gained as a result of an optimized design, based on an extensive architecture-oriented execution analysis of FCP, and the lessons learned with CARMEL-1. CARMEL-2 is a RISC processor in its character and performance. The instruction set includes only 29 carefully selected instructions. The 10 special instructions, the prudent implementation and pipeline scheme, as well as sophisticated mechanisms such as intelligent dereference, distinguish CARMEL-2 as a RISC processor for FCP.     

On the applicability of capability models for small software organizations: does the use of standard processes lead to a better achievement of business goals?

The ISO/IEC 15504 standard implies that the use of its level-based capability model for software process development leads to a better business performance. At capability level 3, this would mean that there is not only a positive correlation but also a causal relation from the use of standard processes to better achievement of business goals. In this paper, we make this claim explicit and challenge it with a counterargument in the context of small software organizations. We argue that in most part, the way the software is designed is what determines the business success in software development, and when application domains are complex socio-technical systems, relying on a standard process instead of human expertise not only fails to answer the promise of process stability but also presents business risks related to poor design, a loss of diversity, and reduced adaptability. With reasons to believe that the standard’s claim is weak in this context, we come up with alternative explanations for why some small software organizations nevertheless use standard processes. Through these hypotheses, we argue that the reasons are not necessarily process-related. In closing, we suggest further studies on how the standard’s notion of process capability and business goals relate to each other when the application domain is not just complicated but complex.     

High-MCC Functions in the Linux Kernel

McCabe’s Cyclomatic Complexity (MCC) is a widely used metric for the complexity of control flow. Common usage decrees that functions should not have an MCC above 50, and preferably much less. However, the Linux kernel includes more than 800 functions with MCC values above 50, and over the years 369 functions have had an MCC of 100 or more. Moreover, some of these functions undergo extensive evolution, indicating that developers are successful in coping with the supposed high complexity. Functions with similarly high MCC values also occur in other operating systems and domains, including Windows. For example, the highest MCC value in FreeBSD is 1316, double the highest MCC in Linux. We attempt to explain all this by analyzing the structure of high-MCC functions in Linux and showing that in many cases they are in fact well-structured (albeit we observe some cases where developers indeed refactor the code in order to reduce complexity). Moreover, human opinions do not correlate with the MCC values of these functions. A survey of perceived complexity shows that there are cases where high MCC functions were ranked as having a low complexity. We characterize these cases and identify specific code attributes such as the diversity of constructs (not only a switch but also ifs) and nesting that correlate with discrete increases in perceived complexity. These observations indicate that a high MCC is not necessarily an impediment to code comprehension, and support the notion that complexity cannot be fully captured using simple syntactic code metrics. In particular, we show that regularity in the code (meaning repetitions of the same pattern of control structures) correlates with low perceived complexity.     

一个基于C/S模式的汉字词属性分析和重组系统的设计

随着ISO10646的出台,庞大的汉字词集的属性分析是一个迫切需要解决的难题,本文主要阐述了采用C/S模式的汉字词属性分析和重组系统的数据模型,并简单介绍了系统的设计要点。     

Performance analysis of SSE and AVX instructions in multi-core CPUs and GPU computing on FDTD scheme for solid and fluid vibration problems

In this work a unified treatment of solid and fluid vibration problems is developed by means of the Finite-Difference Time-Domain (FDTD). The scheme here proposed takes advantage from a scaling factor in the velocity fields that improves the performance of the method and the vibration analysis in heterogenous media. Moreover, the scheme has been extended in order to simulate both the propagation in porous media and the lossy solid materials. In order to accurately reproduce the interaction of fluids and solids in FDTD both time and spatial resolutions must be reduced compared with the set up used in acoustic FDTD problems. This aspect implies the use of bigger grids and hence more time and memory resources. For reducing the time simulation costs, FDTD code has been adapted in order to exploit the resources available in modern parallel architectures. For CPUs the implicit usage of the advanced vectorial extensions (AVX) in multi-core CPUs has been considered. In addition, the computation has been distributed along the different cores available by means of OpenMP directives. Graphic Processing Units have been also considered and the degree of improvement achieved by means of this parallel architecture has been compared with the highly-tuned CPU scheme by means of the relative speed up. The speed up obtained by the parallel versions implemented were up to 3 (AVX and OpenMP) and 40 (CUDA) times faster than the best sequential version for CPU that also uses OpenMP with auto-vectorization techniques, but non includes implicitely vectorial instructions. Results obtained with both parallel approaches demonstrate that massive parallel programming techniques are mandatory in solid-vibration problems with FDTD.     

Learning from syntax generalizations for automatic semantic annotation

Nowadays, there is a huge amount of textual data coming from on-line social communities like Twitter or encyclopedic data provided by Wikipedia and similar platforms. This Big Data Era created novel challenges to be faced in order to make sense of large data storages as well as to efficiently find specific information within them. In a more domain-specific scenario like the management of legal documents, the extraction of semantic knowledge can support domain engineers to find relevant information in more rapid ways, and to provide assistance within the process of constructing application-based legal ontologies. In this work, we face the problem of automatically extracting structured knowledge to improve semantic search and ontology creation on textual databases. To achieve this goal, we propose an approach that first relies on well-known Natural Language Processing techniques like Part-Of-Speech tagging and Syntactic Parsing. Then, we transform these information into generalized features that aim at capturing the surrounding linguistic variability of the target semantic units. These new featured data are finally fed into a Support Vector Machine classifier that computes a model to automate the semantic annotation. We first tested our technique on the problem of automatically extracting semantic entities and involved objects within legal texts. Then, we focus on the identification of hypernym relations and definitional sentences, demonstrating the validity of the approach on different tasks and domains.     

An FAR-SW based approach for webpage information extraction

Automatically identifying and extracting the target information of a webpage, especially main text, is a critical task in many web content analysis applications, such as information retrieval and automated screen reading. However, compared with typical plain texts, the structures of information on the web are extremely complex and have no single fixed template or layout. On the other hand, the amount of presentation elements on web pages, such as dynamic navigational menus, flashing logos, and a multitude of ad blocks, has increased rapidly in the past decade. In this paper, we have proposed a statistics-based approach that integrates the concept of fuzzy association rules (FAR) with that of sliding window (SW) to efficiently extract the main text content from web pages. Our approach involves two separate stages. In Stage 1, the original HTML source is pre-processed and features are extracted for every line of text; then, a supervised learning is performed to detect fuzzy association rules in training web pages. In Stage 2, necessary HTML source preprocessing and text line feature extraction are conducted the same way as that of Stage 1, after which each text line is tested whether it belongs to the main text by extracted fuzzy association rules. Next, a sliding window is applied to segment the web page into several potential topical blocks. Finally, a simple selection algorithm is utilized to select those important blocks that are then united as the detected topical region (main texts). Experimental results on real world data show that the efficiency and accuracy of our approach are better than existing Document Object Model (DOM)-based and Vision-based approaches.     

The occur-check problem in Prolog

We present a method for preprocessing Prolog programs so that their operational semantics will be given by the first-order predicate calculus. Most Prolog implementations do not use a full unification algorithm, for efficiency reasons. The result is that it is possible to create terms having loops in them, whose semantics is not adequately described by first-order logic. Our method finds places where such loops may be created, and adds tests to detect them. This should not appreciably slow down the execution of most Prolog programs.     

藏文编码字符集的扩充集在Linux上的实现

国内藏文软件开发普遍使用的是基于垂直预组合字符的实现方案,但是缺乏统一的编码标准。藏文编码字符集扩充集的推出,对于国内藏文软件的标准化、国际化具有重要意义。本文通过分析ISO/IEC 10646藏文编码字符集基本集、藏文编码字符集扩充集国家标准,区分它们描述字丁的差异,分析由编码方案所导致的实现上的关键问题。最后,针对藏文扩充集B的特殊性,提出并实现了基于Linux国际化架构下支持藏文扩充集标准的解决方案。     

It is time to drop the “R” from NURBS

NURBS were introduced into CAD/CAM systems predominantly for the representation of conventional objects, such as conics and quadrics. Among these, the circle played a critical role in representing a myriad of parts used in the every-day practice. Being the most universally used object, the circle has enjoyed the most popularity in science and engineering. It is an essential entity in both design as well as manufacturing and hence, its representation within CAD/CAM systems requires careful attention. Although the circle enjoys both smoothness as well as a uniform parametrization, its de facto mathematical form, the NURBS form, does not provide either sufficient smoothness or uniform parametrization. On top of all this, NURBS are rational forms requiring homogeneous coordinates in the four-dimensional space, whereas the engineering entity is only Euclidean in 3D. This multiple representational glitch, 3D presence and 4D storage, has given rise to enough headache to warrant reconsideration of the validity of the rational form in engineering design. This paper argues that it is time to drop the “R” from NURBS and to switch to integral splines with approximations where necessary. We also argue that it is time to bury dumb algorithms and consider human-based computing, i.e. our algorithms should be biologically inspired and not based on pure number crunching.     

How to invent a Prolog machine

In this paper we study the compilation of Prolog by making visible hidden operations (especially unification), and then optimizing them using well-known partial evaluation techniques. Inspection of straightforward partially evaluated unification algorithms gives an idea how to design special abstract machine instructions which later form the target language of our compilation. We handle typical compiler problems like representation of terms explicitly. This work gives a logical reconstruction of abstract Prolog machine code, and represents an approach of constructing a correct compiler from Prolog to such a code. As an example, we are explaining the unification principles of Warren’s New Prolog Engine within our framework.