Ljiljana Brankovic

• University of New England

In order to better understand conditions that lead to methane explosions in underground coal mines, we apply machine learning to data collected in an industrial scale research project carried out at the University of Newcastle, Australia, 2014–2018 (VAM Abatement Safety Project). We present a comparison of five different methods (Decision Tree, Ran...

This paper surveys the main computer search results for finding graceful labeling of trees. The paper is devoted to the memory of Mirka Miller, who made an outstanding contribution to the area of graph labeling.

We survey the most important results regarding the domination chain parameters, including the characterisation of the domination sequence, complexity of exact and parameterised algorithms, and approximation and inapproximability ratios. We provide a number of new results for the upper and lower irredundance and their complements, and a few results...

Nowadays huge amount of data is regularly being collected for various purposes by organizations and companies, including business, government departments, and medical service providers. Data mining techniques are often used on these gigantic datasets to discover previously hidden information. Upon release of these datasets for data mining, individu...

Context: Nowadays most businesses in Australia maintain a website to advertise their products and services and some to also conduct online sales and payments. Many have an additional Facebook page or utilise other on-line tools and phone apps. Data is now considered to be one of the most valuable assets of companies, and many are using Cloud servic...

The concept of face-antimagic labeling of plane graphs was introduced by Mirka Miller in 2003. This survey aims to give an overview of the recent results obtained in this topic.

This paper studies Upper Domination, i.e., the problem of computing the maximum cardinality of a minimal dominating set in a graph with respect to classical and parameterised complexity as well as approximability.

We consider Upper Domination, the problem of finding a maximum cardinality minimal dominating set in a graph. We show that this problem does not admit an \(n^{1-\epsilon }\) approximation for any \(\epsilon >0\), making it significantly harder than Dominating Set, while it remains hard even on severely restricted special cases, such as cubic graphs...

This paper studies Upper Domination, i.e., the problem of computing the maximum cardinality of a minimal dominating set in a graph, with a focus on parameterised complexity. Our main results include W[1]-hardness for Upper Domination, contrasting FPT membership for the parameterised dual Co-Upper Domination. The study of structural properties also...

Providing a global understanding of privacy is crucial, because everything is connected. Nowadays companies are providing their customers with more services that will give them more access to their data and daily activity; electricity companies are marketing the new smart meters as a new service with great benefit to reduce the electricity usage by...

In this paper, we survey and supplement the complexity landscape of the domination chain parameters as a whole, including classifications according to approximability and parameterised complexity. Moreover, we provide clear pointers to yet open questions. As this posed the majority of hitherto unsettled problems, we focus on Upper Irredundance and...

The Minimum Vertex Cover (MinVC) problem is a well-known NP-hard problem. Recently there has been great interest in solving this problem on real-world massive graphs. For such graphs, local search is a promising approach to finding optimal or near-optimal solutions. In this paper we propose a local search algorithm that exploits reduction rules and...

In this paper we study combinatorial and algorithmic resp. complexity questions of upper domination, i.e., the maximum cardinality of a minimal dominating set in a graph. We give a full classification of the related maximisation and minimisation problems, as well as the related parameterised problems, on general graphs and on graphs of bounded degr...

DNA sequencing is the process of determining the exact order of the nucleotide bases of an individual's genome in order to catalogue sequence variation and understand its biological consequences. Whole-genome sequencing techniques currently produce masses of data in the form of short sequences known as reads. Assembling these reads into a whole gen...

Due to their openness and low publishing barrier nature, User-Generated Content (UGC) platforms facilitate the creation of huge amounts of inaccurate content. Consequently, assessing UGC information credibility is developing into a vitally important research topic. This paper offers a systematic review of the current developments in assessing infor...

It is well recognised that data mining and statistical analysis pose a serious treat to privacy. This is true for financial, medical, criminal and marketing research. Numerous techniques have been proposed to protect privacy, including restriction and data modification. Recently proposed privacy models such as differential privacy and k-anonymity r...

This report presents the current state and approach in Building Information Modelling (BIM). The report is focussed at providing a desktop audit of the current state and capabilities of the products and applications supporting BIM. This includes discussion on BIM model servers as well as discipline specific applications, for which the distinction i...

This paper discusses the preliminary findings of an ongoing research project aimed at developing a technological, operational and strategic analysis of adopting BIM in AEC/FM (Architecture-Engineering-Construction/Facility Management) industry as a collaboration tool. Outcomes of the project will provide specifications and guidelines as well as est...

Building Information Modelling (BIM) is an IT enabled technology that allows storage, management, sharing, access, update and use of all the data relevant to a project through out the project life-cycle in the form of a data repository. BIM enables improved inter-disciplinary collaboration across distributed teams, intelligent documentation and inf...

In order to protect privacy of social network participants, network graph data should be anonymised prior to its release. Most proposals in the literature aim to achieve k-anonymity under specific assumptions about the background information available to the attacker. Our method is based on randomizing the location of the triangles in the graph. We...

Due to the growing dependence on the WWW User- Generated Content (UGC) as a primary source for information and news, the research on web credibility is becoming more important than ever before. In this paper we review previous efforts to evaluate information credibility, focusing specifically on microblogging. In particular, we provide a comparison...

Parameterised approximation is a relatively new but growing field of interest. It merges two ways of dealing with NP-hard optimisation problems, namely polynomial approximation and exact parameterised (exponential-time) algorithms. We exemplify this idea by designing and analysing parameterised approximation algorithms for minimum vertex cover. Mor...

The paper deals with the problem of labeling the vertices and edges of a plane graph in such a way that the labels of the vertices and edges surrounding that face add up to a weight of that face. A labeling of a plane graph is called d-antimagic if for every positive integer s, the s-sided face weights form an arithmetic progression with a differen...

Privacy preserving data mining and statistical disclosure control have received a great deal of attention during the last few decades. Existing techniques are generally classified as restriction and data modification. Within data modification techniques noise addition has been one of the most widely studied but has traditionally been applied to num...

The aim of this study was to discover the public's attitude and views towards privacy in health care. This is a part of a larger project which aims to gain an insight into what kind of privacy is needed and develop technical measures to provide such privacy. The study was a two-stage process which combined qualitative and quantitative research. Sta...

During the whole process of data mining (from data collection to knowledge discovery) various sensitive data get exposed to several parties including data collectors, cleaners, preprocessors, miners and decision makers. The exposure of sensitive data can potentially lead to breach of individual privacy. Therefore, many privacy preserving techniques...

We are going to analyze simple search tree algorithms for approximating d -Hitting Set, focussing on the case of factor-2 approximations for d = 3. We also derive several results for hypergraph instances of bounded degree, including a new polynomial-time approximation.

Given a positive value r, a distance-based range query returns the objects that lie within the distance r of the query location. In this paper, we focus on the distance-based range queries that continuously change their locations in a euclidean space. We present an efficient and effective monitoring technique based on the concept of a safe zone. Th...

The lower and the upper irredundance numbers of a graph G, denoted ir(G) and IR(G), respectively, are conceptually linked to the domination and independence numbers and have numerous relations to other graph parameters. It has been an open question whether determining these numbers for a graph G on n vertices admits exact algorithms running in time...

This paper deals with the problem of labeling the vertices, edges and faces of a plane graph. A weight of a face is the sum of the label of a face and the labels of the vertices and edges surrounding that face. In a super d-antimagic labeling the vertices receive the smallest labels and the weights of all s-sided faces constitute an arithmetic prog...

This paper takes a close look at graceful labelling and its applications. We pay special attention to the famous Graceful Tree Conjecture, which has attracted a lot of interest and engaged many researchers over the last 40+ years, and yet to this day remains unsolved. We describe applications of graceful and graceful-like labellings of trees to sev...

The lower and the upper irredundance numbers of a graph G, denoted ir(G) and IR(G), respectively, are conceptually linked to the domination and independence numbers and have numerous relations to other graph parameters. It has been an open question whether determining these numbers for a graph G on n vertices admits exact algorithms running in time...

We explore opportunities for parameterising constant factor approximation algorithms for vertex cover. We provide a simple algorithm that works on any approximation ratio of the form \frac 2l+1l+1\frac {2l+1}{l+1} and has complexity that outperforms an algorithm by Bourgeois et al. derived from a sophisticated exact parameterised algorithm. In pa...

Suppose G is a finite graph with vertex-set V(G) and edge-set E(G). An (a,d)-edge-antimagic total labeling on G is a one-to-one map f from V(G) U E(G) onto the integers 1,2,..., |V(G)| + |E(G)| with the property that the edge-weights w(uv)=f(u)+f(v)+f(uv) form an arithmetic progression starting from a and having common difference d. Such a labeling...

The lower and the upper irredundance numbers of a graphG, denoted ir(G) and IR(G) respectively, are conceptually linked to domination and independence numbers and have numerous relations to other graph parameters. It is a long-standing open question whether determining these numbers for a graph G on n vertices admits exact algorithms running in tim...

Sensor networks are ad-hoc mobile networks that include sensor nodes with limited computational and communication capabilities. They have become an economically viable monitoring solution for a wide variety of applications. Obviously, it is important to ensure security and, taking into account limited resources available in wireless sensor networks...

Given a positive value r, a circular range query returns the objects that lie within the distance r of the query location. In this paper, we study the circular range queries that continuously change their locations. We present an efficient and effective technique to monitor such moving range queries by utilising the concept of a safe zone. The safe...

In this paper we show that the output sequences of the generalized self-shrinking generator are particular solutions of a binary homogeneous linear difference equation. In fact, all these sequences are just linear combinations of primary sequences weighted by binary coefficients. We show that in addition to the output sequences of the generalized s...

This chapter presents a comprehensive analysis of the current state of Building Information Modelling (BIM) in the Architecture, Engineering, Construction and Facility Management (AEC/FM) industry and a re-assessment of its role and potential contribution in the near future, given the apparent slow rate of adoption by the industry. The chapter anal...

This chapter discusses an action research study towards the development of a decision framework to support a fully integrated multi disciplinary Building Information Model (BIM) using a Model Server. The framework was proposed to facilitate multi disciplinary collaborative BIM adoption through, informed selection of a project specific BIM approach...

The lower and the upper irredundance numbers of a graph $G$, denoted $ir(G)$ and $IR(G)$ respectively, are conceptually linked to domination and independence numbers and have numerous relations to other graph parameters. It is a long-standing open question whether determining these numbers for a graph $G$ on $n$ vertices admits exact algorithms run...

The statistical analysis of data stored in data warehouses is an important phase in the organisation's strategic planning process. For the maximum benefit to be gained from such data warehouses, a relationship of trust needs to exist between all parties involved. In this paper we investigate its importance with respect to the statistical security p...

Statistical database security is an important problem that has major implications for privacy and protection in the computerised, online world. In this paper we prove that the bounds on the number of answerable range queries in a 1-dimensional statistical database of size n for n odd, or n even and greater than 52, derived in [4] in fact hold for a...

Building Information Modelling (BIM) is an information technology [IT] enabled approach to managing design data in the AEC/FM (Architecture, Engineering and Construction/ Facilities Management) industry. BIM enables improved interdisciplinary collaboration across distributed teams, intelligent documentation and information retrieval, greater consis...

BIM (Building Information Modelling) is an approach that involves applying and maintaining an integral digital representation of all building information for different phases of the project lifecycle. This paper presents an analysis of the current state of BIM in the industry and a re-assessment of its role and potential contribution in the near fu...

Despite enormous benefits and the extremely fast proliferation of data mining in recent years, data owners and researchers alike have acknowledged that data mining also revives old and introduces new threats to individual privacy. Many believe that data mining is, and will continue to be, one of the most significant privacy challenges in years to c...

Statistical database security focuses on the protection of confidential individual values stored in so-called statistical databases and used for statistical purposes. Examples include patient records used by medical researchers, and detailed phone call records, statistically analyzed by phone companies in order to improve their services. This probl...

Mobile agents are programs that travel autonomously through a computer network in order to perform some computation or gather information on behalf of a human user or an application. In the last several years, mobile agents have found numerous applications including e-commerce. In most applications, the security of mobile agents is of the utmost im...

Mobile agents are programs that travel autonomously through a computer network in order to perform some computation or gather information on behalf of a human user or an application. In the last several years numerous applications of mobile agents have emerged, including e-commerce. However, mobile agent paradigm introduces a number security threat...

Data Mining is a powerful tool for information discovery from huge datasets. Various sectors, including commercial, government, financial, medical, and scientific, are applying Data Mining techniques on their datasets that typically contain sensitive individual information. During this process the datasets get exposed to several parties, which can...

Mobile agents are programs that travel autonomously through a computer network in order to perform some computation or gather information on behalf of a human user or an application. In the last several years, mobile agents have found numerous applications including e-commerce. In most applications, the security of mobile agents is of the utmost im...

If $T=(V,E)$ is a tree on vertex set $V$, where $|V|=n$, a labelling of $T $ is a bijection $\phi$ from $V$ to $\{1,2,\dots,n\}$. The labelling induces an edge labelling ${\overline \phi}: E\rightarrow \{1,2,\dots,n-1\}$ by ${\overline \phi}(e)=|\phi(u)-\phi(v)|$ for $e=uv\in E$. The size of the labelling $\phi$ is $|{\overline \phi}(E)|$. A labell...

A graceful labelling of an undirected graph $G$ with $n$ edges is a one-to-one function from the set of vertices of $G$ to the set $\{0,1,2,\ldots,n\}$ such that the induced edge labels are all distinct. An induced edge label is the absolute value of the difference between the two end-vertex labels. The Graceful Tree Conjecture states that all tree...

Nowadays organizations all over the world are dependent on mining gigantic datasets. These datasets typically contain delicate individual information, which inevitably gets exposed to different parties. Consequently privacy issues are constantly under the limelight and the public dissatisfaction may well threaten the exercise of data mining and all...

Nowadays organizations all over the world are dependent on mining gigantic datasets. These datasets typically contain delicate individual information, which inevitably gets exposed to different parties. Consequently privacy issues are constantly under the limelight and the public dissatisfaction may well threaten the exercise of data mining and all...

Nowadays huge amount of data is regularly being collected for various purposes by organizations and companies, including business, government departments, and medical service providers. Data mining techniques are often used on these gigantic datasets to discover previously hidden information. Upon release of these datasets for data mining, individu...

We introduce the notion of the L-core of a graph what enables a simple description of some properties of the eigenspace of the eigenvalue −2 in gen-eralized line graphs and an elegant formulation of the solution of a problem in the security of data in statistical databases.

Many believe that data mining poses the biggest privacy challenge in the next decade. In this paper we concentrate on threats to privacy arising from the possibility of combining aggregate data to deduce the confidential individual values. We determine the maximum number of sum totals that can be disclosed without leading to a 2-compromise in a 1-d...

We introduce the notion of premature partial latin squares; these cannot be completed, but if any of the entries is deleted, a completion is possible. We study their spectrum, i.e., the set of integers t such that there exists a premature partial latin square of order n with exactly t nonempty cells.

A statistical database is said to be secure if no sensitive statistics are disclosed. An important problem in security of statistical databases is to maximize the number of disclosed statistics, while ensuring that the database is secure. In this paper we present a new result for the case of range queries in 1-dimensional statistical databases and...

Let D = {a(1),..., a(n)} be a set of real numbers, and let S subset of {1,..., n}. For an interval I subset of {1,..., n} we set SU M (I) = Sigma(i is an element of I) a(i). In this paper we solve the following problem which has been asked in connection with security of statistical databases: Find a largest family B of subintervals of {1,..., n} so...

The recent proliferation of data mining tools for the analysis of large volumes of data has paid little attention to individual privacy issues. Here, we introduce methods aimed at finding a balance between the individuals’ right to privacy and the data-miners’ need to find general patterns in huge volumes of detailed records. In particular, we focu...

We say that an antichain A in the boolean lattice B n is flat if there exists an integer k # 0 such that every set in A has cardinality either k or k +1. Define the volume of A to be # A#A |A|. We prove that for every antichain A in B n there exist an antichain which is flat and has the same volume as A. the electronic journal of combinatorics 6 (1...

Let A be a k-dimensional matrix of size d 1 Theta:::Thetad k : By a contiguous submatrix B of A we understand the matrix B = fa i 1 :::i k g; i 1 :::i k 2 I 1 Theta ::: Theta I k ;where I s is an interval, I s ae f1; :::; d s g; s = 1; :::; k: For a contiguous submatrix B we denote by SUM(B) the sum of all elements of B. The following question has...

Recent developments in information technology have enabled collection and processing of vast amounts of personal data, such as criminal records, shopping habits, credit and medical history, and driving records. This information is undoubtedly very useful in many areas, including medical research, law enforcement and national security. However, ther...

Voltage graphs are a powerful tool for constructing large graphs (called lifts) with prescribed properties as covering spaces of small base graphs. This makes them suitable for application to the degree/diameter problem,whichis to determine the largest order of a graph with given degree and diameter. Many currently known largest graphs of degree #...

The usability of a statistical database is defined to be the ratio of the cardinality of the largest set of queries which can be answered without compromise to the total number of queries. In this paper, we present new results concerning the usability of secure statistical databases for general SUM, COUNT and MEAN queries, as well as for the corres...

The usability of a statistical database is defined to be the ratio of the cardinality of the largest set of queries which can be answered without compromise to the total number of queries. In this paper, we present new results concerning the usability of secure statistical databases for general SUM, COUNT and MEAN queries, as well as for the corres...

The motivation for this work comes from a security problem of statistical databases: In a database of n records, given k SUM queries, is it possible to answer all of them, plus another n⌊n 2⌋-k distinct SUM queries, in such a way that no individual value from the database is revealed? The corresponding mathematical problem (stated in terms of certa...

In this paper we give an overview of smart card technology how a smart card could be used as a healthcare card and the benefits that would most likely result from doing so. The smart card memory can be zoned into different security levels. The top security zone may contain an individual's full medical history while the lowest security zone may cont...

With the recent advances in genetic and computer technology, enormous databases containing genetic information have become available for research and other purposes. An example of such databases is the Icelandic Health Database containing health and genetic records about the total population of Iceland. This has raised many privacy and ethical ques...

In recent years advances in technology facilitated collection and storage of vast amount of data. Many organizations, including large and small businesses, and hospitals and government bodies rely on data for day-to-day operation as well as marketing, planning and research purposes. Examples include criminal records used by law enforcement and nati...

Voltage graphs are a powerful tool for constructing large graphs (called lifts) with prescribed properties as covering spaces of small base graphs. This makes them suitable for application to the degree/diameter problem, which is to determine the largest order of a graph with given degree and diameter. Many currently known largest graphs of degree≤...