Efficient Closed Pattern Mining in the Presence of Tough Block Constraints

In recent years, various constrained frequent pattern mining problem formulations and associated algorithms have been developed that enable the user to specify various itemsetbased constraints that better capture the underlying application requirements and characteristics. In this paper we introduce a new class of block constraints that determine the significance of an itemset pattern by considering the dense block that is formed by the pattern's items and its associated set of transactions. Block constraints provide a natural framework by which a number of important problems can be specified and make it possible to solve numerous problems on binary and real-valued datasets. However, developing computationally e#cient algorithms to find these block constraints poses a number of challenges as unlike the di#erent itemset-based constraints studied earlier, these block constraints are tough as they are neither anti-monotone, monotone, nor convertible. To overcome this problem, we introduce a new class of pruning methods that can be used to significantly reduce the overall search space and make it possible to develop computationally e#cient block constraint mining algorithms. We present an algorithm called CBMiner that takes advantage of these pruning methods to develop an algorithm for finding the closed itemsets that satisfy the block constraints. Our extensive performance study shows that CBMiner generates more concise result set and can be order(s) of magnitude faster than the traditional frequent closed itemset mining algorithms

Clafer: Lightweight Modeling of Structure, Behaviour, and Variability

Embedded software is growing fast in size and complexity, leading to intimate mixture of complex architectures and complex control. Consequently, software specification requires modeling both structures and behaviour of systems. Unfortunately, existing languages do not integrate these aspects well, usually prioritizing one of them. It is common to develop a separate language for each of these facets. In this paper, we contribute Clafer: a small language that attempts to tackle this challenge. It combines rich structural modeling with state of the art behavioural formalisms. We are not aware of any other modeling language that seamlessly combines these facets common to system and software modeling. We show how Clafer, in a single unified syntax and semantics, allows capturing feature models (variability), component models, discrete control models (automata) and variability encompassing all these aspects. The language is built on top of first order logic with quantifiers over basic entities (for modeling structures) combined with linear temporal logic (for modeling behaviour). On top of this semantic foundation we build a simple but expressive syntax, enriched with carefully selected syntactic expansions that cover hierarchical modeling, associations, automata, scenarios, and Dwyer's property patterns. We evaluate Clafer using a power window case study, and comparing it against other notations that substantially overlap with its scope (SysML, AADL, Temporal OCL and Live Sequence Charts), discussing benefits and perils of using a single notation for the purpose

gPrune: A Constraint Pushing Framework for Graph Pattern Mining

Abstract. In graph mining applications, there has been an increasingly strong urge for imposing user-specified constraints on the mining results. However, unlike most traditional itemset constraints, structural constraints, such as density and diameter of a graph, are very hard to be pushed deep into the mining process. In this paper, we give the first comprehensive study on the pruning properties of both traditional and structural constraints aiming to reduce not only the pattern search space but the data search space as well. A new general framework, called gPrune, is proposed to incorporate all the constraints in such a way that they recursively reinforce each other through the entire mining process. A new concept, Pattern-inseparable Data-antimonotonicity, is proposed to handle the structural constraints unique in the context of graph, which, combined with known pruning properties, provides a comprehensive and unified classification framework for structural constraints. The exploration of these antimonotonicities in the context of graph pattern mining is a significant extension to the known classification of constraints, and deepens our understanding of the pruning properties of structural graph constraints.

The impact of organisational culture on gold mining activities in the Free State

Thesis (M. Comm.) -- Central University of Technology, Free State, 2007From the Stone Age, each nation or group of people has had a distrust of those different from themselves. This is evidenced in various ways, for example, social welfare given to local residents only, scornful names given to foreigners and other ethnic groups and rituals designed to keep themselves separate from others. These incidents of diversity resulted into an unplanned and emergent set of norms, values and beliefs that exert enormous influence on the way in which an organisation operates, how organisational structure is developed, the integration and adaptation of internal and external relationships, as well as the orientation of the underlying values of the organisation. The main aim of changing culture is to improve organisational performance. To achieve this aim, it requires an understanding of the underlying assumptions and values that determine what is important in an organisation as well as assessment of the impact of culture on operational efficiency. The impact of organisational culture is identified through the negative and positive outcomes of mining activities, and is illustrated by employee satisfaction, job commitment, organisational loyalty, turnover, absenteeism and productivity. The aim of this research study was to identify the characteristics of organisational culture and evaluate the impact of organisational culture on gold mining activities in the Free State. The methodology used in this study comprises of empirical as well as a literature study. Questionnaires and interviews were used to gather information for the empirical study. The empirical study revealed that firstly, organisational culture is created partially by leaders, and that one of the most critical functions of leadership is the creation and the management of culture. Lastly, organisational culture emerges when employees think, believe and act according to the pressures and priorities of their environment. Unfortunately, employees do not set aside their cultural values and lifestyle preferences when they come to work. It is the responsibility of the management to create an environment that is conducive to a healthy working environment. This study established that the necessity to control the workforce productivity need not be accompanied by ruthless or aggressive exploitation of cultural management, but by reliance on employees’ capability to exercise judgement to cope effectively with environmental uncertainty. Rules, norms and strategies developed cannot “fit” every circumstance but encourage conformity rather than creativity, and compliance rather than commitment

Object Detection in 20 Years: A Survey

Object detection, as of one the most fundamental and challenging problems in computer vision, has received great attention in recent years. Its development in the past two decades can be regarded as an epitome of computer vision history. If we think of today's object detection as a technical aesthetics under the power of deep learning, then turning back the clock 20 years we would witness the wisdom of cold weapon era. This paper extensively reviews 400+ papers of object detection in the light of its technical evolution, spanning over a quarter-century's time (from the 1990s to 2019). A number of topics have been covered in this paper, including the milestone detectors in history, detection datasets, metrics, fundamental building blocks of the detection system, speed up techniques, and the recent state of the art detection methods. This paper also reviews some important detection applications, such as pedestrian detection, face detection, text detection, etc, and makes an in-deep analysis of their challenges as well as technical improvements in recent years.Comment: This work has been submitted to the IEEE TPAMI for possible publicatio

Environmental quality conditions in Fairbanks, Alaska, 1972

Published by The Institute of Water Resources and The Institute of Social, Economic and Government Research Fairbanks, AlaskaThis study represents a starting point for investigating the nature and interconnectivity of environmental quality problems in Fairbanks in the 1970's. Since the Fairbanks flood of 1967, no detailed survey of environmental quality conditions has been conducted despite the impact of the flood, the considerable expansion of the city limits, and the population expansion (anticipated and actual) associated with the oil pipeline. The study focuses on selective aspects of environmental quality of continuing and increasing concern to Fairbanks area residents and also to the city and borough governments. Specifically, the issues analyzed are (1) the environmental setting of the area, (2) structures, especially housing conditions, (3) premise conditions, and (4) waste control. Much of the data was derived from a program called NEEDS, an acronym for Neighborhood Environmental Evaluation and Decision System. NEEDS was developed by the Bureau of Community Environmental Management of the Department of Health, Education, and Welfare for rapid gathering of environmental, health, and social information in urban areas.1 The NEEDS survey design consists of two separate stages. Stage I is concerned with collecting general environmental quality information to determine geographically where the most pronounced environmental health problems exist in a given urban area. Stage II consists of detailed interviews with residents of the identified "problem areas" to determine the exact nature of existing health and environmental problems, e.g., housing, health, availability of services, and attitudes regarding existing government (local, state, and federal) programs. With this information, local officials could begin to reorganize existing programs and/or develop new programs to solve some of the interrelated environmental quality problems in the disadvantaged sections of their cities.The work upon which this report is based was supported by funds provided by the State of Alaska, the University of Alaska at Fairbanks, the United States Public Health Service, and the Office of Water Research and Technology

Reforms and Counter-Reforms in Bolivia

This paper analyzes the process of reforms and counter-reforms witnessed in Bolivia over the last two and a half decades, and the effects these processes have had on productivity. In addition, the paper discusses the changing nature of the policy- making processes underlying the reform and counter-reform processes, in terms of the actors who participated in the PMP, policy domains, and arenas where the PMP was shaped, and the currencies used by different actors in order to press for their demands. Moreover, the paper analyzes the factor underlying the changes which took place in the support given by the population to the reform process.Reforms, Productivity, Political Economy, Bolivia

Trade and Investment Liberalization Effects on SME Development: A Literature Review and a Case Study of Indonesia

As this research seeks to bring to the fore benefits that have been or may be derived for SMEs from international trade and investment liberalization in Indonesia, it has three main questions: (1). how international trade and investment policy reforms affect local SMEs; (2) has growth of exports of SMEs accelerated since the reforms; and (3) does investment liberalization generate more subcontracting between local SMEs and FDI.?Trade and Investment, SME, Indonesia