# Benedict Sheung Hung PoonUniversity of Technology Brunei (UTB), Brunei Darussalam

Benedict Sheung Hung Poon

PhD in Computer Science

## About

89

Publications

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712

Citations

Citations since 2017

## Publications

Publications (89)

Geographical visualization systems, such as online maps, provide interactive operations of continuous zooming and panning. With consistent dynamic map labeling, users can navigate continuously in the map areas such that labels are not allowed to exhibit abrupt change in terms of their positions or sizes, and labels should not suddenly disappear or...

Given a seller with k types of items and n single-minded buyers, i.e., each buyer is only interested in a particular bundle of items, to maximize the revenue, the seller must assign some amount of bundles to each buyer with respect to the buyer's accepted price. Each buyer bi is associated with a value function vi(⋅) such that vi(x) is the accepted...

Geographical visualization systems, such as online maps, provide interactive operations of continuous zooming and panning. With consistent dynamic map labeling, users can navigate continuously through space without distractions such as popping and jumping. However, existing work on consistent dynamic map labeling only study the problem of optimizin...

Uniformly inserting points on the sphere has been found useful in many scientific and engineering fields. Different from the offline version where the number of points is known in advance, we consider the online version of this problem. The requests for point insertion arrive one by one and the target is to insert points as uniformly as possible. T...

The present study is undertaken among Information and Communication Technology Centers (ICTCs) among four higher education institutions (HEIs) in Brunei Darussalam to evaluate and highlight their performance in achieving IT Governance using a performance measuring COBIT framework. The COBIT also assesses the maturity level indicators from the range...

Bus transit is not popular in Brunei partly due to high ownership of private cars and this will lead to severe traffic congestion in the future. This paper discusses the design of a mobile application to sustain an incentive scheme for public bus transportation in Brunei. It supports a case study on whether an incentive scheme has impact to increas...

Given a collection $L$ of line segments, we consider its arrangement and study the problem of covering all cells with line segments of $L$. That is, we want to find a minimum-size set $L'$ of line segments such that every cell in the arrangement has a line from $L'$ defining its boundary. We show that the problem is NP-hard, even when all segments...

Consistently placing annotation labels across map scales often poses a problem due to the restriction of the screen space. This problem becomes further exacerbated when we navigate by arbitrarily zooming in and out of digital maps on mobile devices. In this paper, we introduce leader lines to conventional techniques for scale-aware consistent label...

We study the following scheduling problem on a single processor. We are given n jobs, where each job \(j_i\) has an integer release time \(r_i\), processing time \(p_i\) as well as deadline \(d_i\). The processor can schedule an unlimited number of jobs at any time t. Our objective is to schedule the jobs together such that the total number of acti...

A total vertex cover is a vertex cover whose induced subgraph consists of a set of connected components, each of which contains at least two vertices. A t-total vertex cover is a total vertex cover where each component of its induced subgraph contains at least t vertices. The total vertex cover (TVC) problem and the t-total vertex cover (t-TVC) pro...

In many scientific and engineering applications, there are occasions where points need to be inserted uniformly onto a sphere. Previous works on uniform point insertion mainly focus on the offline version, i.e., to compute N positions on the sphere for a given interger N with the objective to distribute these points as uniformly as possible. An exa...

We consider the dynamic map labeling problem: given a set of rectangular labels on the map, the goal is to appropriately select visible ranges for all the labels such that no two consistent labels overlap at every scale and the sum of total visible ranges is maximized. This is also called the _active range optimization_ (ARO) problem defined by Bee...

Outline fonts use Bézier curves to describe the outer boundaries of the characters of specific outline fonts. In this paper, we consider the interpolation problem between two different but quite similar outline fonts. Since the compositions of different outline fonts of a character may be different, such as the total number of curves a font of the...

The problem of finding k-edge-connected components is a fundamental problem in computer science. Given a graph G = (V, E), the problem is to partition the vertex set V into {V1, V2,…, Vh}, where each Vi is maximized, such that for any two vertices x and y in Vi, there are k edge-disjoint paths connecting them. In this paper, we present an algorithm...

Let \(G=(V,E)\) be an undirected graph. A minus dominating function for G is a function \(f:V \rightarrow \{-1, 0,+1\}\) such that for each vertex \(v \in V\), the sum of the function values over the closed neighborhood of v is positive. The weight of a minus dominating function f for G, denoted by w(f(V)), is \(\sum f(v)\) over all vertices \(v \i...

We consider the bracing problem of a square grid framework possibly with holes and present an efficient algorithm for making the framework infinitesimally rigid by augmenting it with the minimum number of diagonal braces. This number of braces matches the lower bound given by Gáspár, Radics and Recski [2]. Our contribution extends the famous result...

A signed dominating function for a graph \(G=(V, E)\) is a function \(f\): \(V \rightarrow \{ +1, -1\}\) such that for all \(v \in V\), the sum of the function values over the closed neighborhood of \(v\) is at least one. The weight \(w(f(V))\) of signed dominating function \(f\) for vertex set \(V\) is the sum of \(f(v)\) for \(v \in V\). The sign...

We investigate straight-line drawings of topological graphs that consist of a
planar graph plus one edge, also called almost-planar graphs. We present a
characterization of such graphs that admit a straight-line drawing. The
characterization enables a linear-time testing algorithm to determine whether
an almost-planar graph admits a straight-line d...

We first present polynomial algorithms to compute the independence number of the categorical product for two cographs or two splitgraphs, respectively. Then we prove that computing the maximum independent set of the categorical product of a planar graph of maximum degree three and a is NP-complete. The ultimate categorical independence ratio of a g...

Given a collection L of line segments, we consider its arrangement and study the problem of covering all cells with line segments of L. That is, we want to find a minimum-size set \(L'\) of line segments such that every cell in the arrangement has a line from \(L'\) defining its boundary. We show that the problem is NP-hard, even when all segments...

We show that there exist linear-time algorithms that compute the strong chromatic index and a maximum induced matching of tree-cographs when the decomposition tree is a part of the input. We also show that there exist efficient algorithms for the strong chromatic index of (bipartite) permutation graphs and of chordal bipartite graphs.

We investigate square-orthogonal drawings of non-planar graphs with vertices represented as unit grid squares. We present quadratic-time algorithms to construct the square-orthogonal drawings of 5-graphs, 6-graphs, and 8-graphs such that each edge in the drawing contains at most two, two, and three bends, respectively. In particular, the novel anal...

An independent dominating set of a graph G is a subset D of V such that every vertex not in D is adjacent to at least one vertex of D and no two vertices in D are adjacent. The independent dominating set (IDS) problem asks for an independent dominating set with minimum cardinality. First, we show that the independent dominating set problem and the...

An edge-unfolding of a polyhedron is a cutting of the polyhedron’s surface along its edges so that its surface can be flattened into a single connected flat patch on the plane without any self-overlapping. A one-layer lattice polyhedron is a polyhedron of height one, whose surface faces are grid squares. We consider the edge-unfolding problem on se...

We consider the dynamic map labeling problem: given a set of rectangular labels on the map, the goal is to appropriately select visible ranges for all the labels such that no two consistent labels overlap at every scale and the sum of total visible ranges is maximized. We propose approximation algorithms for several variants of this problem. For th...

Given a graph G and integers b and w. The black-and-white coloring problem asks if there exist disjoint sets of vertices B and W with vertical bar B vertical bar = b and vertical bar W vertical bar = w such that no vertex in B is adjacent to any vertex in W. In this paper we show that the problem is polynomial when restricted to cographs, interval...

Boundary labeling connects each point site in a rectangular map to a label on the sides of the map by a leader, which may be a straight-line segment or a polyline. In the conventional setting, the labels along a side of the map form a single stack of labels in which labels are placed consecutively one by one in a sequence, and the two end sides of...

This paper is concerned with the crossing number of Euclidean minimum-weight Laman graphs in the plane. We first investigate the relation between the Euclidean minimum-weight Laman graph and proximity graphs, and then we show that the Euclidean minimum-weight Laman graph is quasi-planar and 6-planar. Thus the crossing number of the Euclidean minimu...

Chartrand, Haynes, Henning and Zhang introduced a variation of domination called stratified domination in graphs. This paper studies stratified domination from an algorithmic point of view. A 2-stratified (or black–white) graph is a graph in which every vertex is colored black or white. Given a black-white graph F rooted at a white vertex v, an F-c...

We investigate square-orthogonal drawings of non-planar graphs with vertices represented as unit grid squares. We present quadratic-time algorithms to construct the square-orthogonal drawings of 5-graphs, 6-graphs, and 8-graphs such that each edge in the drawing contains at most two, two, and three bends, respectively. In particular, the novel anal...

We first present polynomial algorithms to compute maximum independent sets in the categorical products of two cographs or two splitgraphs, respectively. Then we prove that computing the independent set of the categorical product of a planar graph of maximal degree three and K
4 is NP-complete. The ultimate categorical independence ratio of a graph...

Mobile computing has developed exponentially in the last decade, and these days the world is well into the mobile era. Smart mobile devices, including tablets, pads and smartphones, have left the labs and have become essential in people's lives. Mobile computing will continue to grow in the next few years in power and pervasiveness and is poised to...

We show that there are polynomial-time algorithms to compute maximum
independent sets in the categorical products of two cographs and two
splitgraphs. We show that the ultimate categorical independence ratio is
computable in polynomial time for cographs.

Let G be a graph. The independence-domination number γ
i
(G) is the maximum over all independent sets I in G of the minimal number of vertices needed to dominate I. In this paper we investigate the computational complexity of γ
i
(G) for graphs in several graph classes related to cographs. We present an exact exponential algorithm. We show that the...

We consider the question whether the edges of a graph can be partitioned into a set of triangles. We propose a linear-time algorithm to partition the edges of a planar graph into triangles. We also obtain a polynomial-time algorithm for toroidal graphs. On the other hand, we show that it is NP-complete for k-planar graphs, where k≥8.

A set of edges in a graph G is independent if no two elements are contained in a clique of G. The edge-independent set problem asks for the maximal cardinality of independent sets of edges. We show that the edge-clique graphs of cocktail parties have unbounded rankwidth. There is an elegant formula that solves the edge-independent set problem for g...

The stretch factor and maximum detour of a graph G embedded in a metric space measure how well G approximates the minimum complete graph containing G and the metric space, respectively. In this paper we show that computing the stretch factor of a rectilinear path in L 1 plane has a lower bound of Ω(nlogn) in the algebraic computation tree model and...

The domatic number of a graph G, denoted by DN(G), is the maximum number k such that V can be partitioned into k disjoint dominating sets. The domatic partition problem is to find a partition of the vertices of G into DN(G) dominating sets. The k-domatic partition problem with fixed k is to find a partition of the vertices of G into k dominating se...

We show that edge-clique graphs of cocktail party graphs have unbounded
rankwidth. This, and other observations lead us to conjecture that the
edge-clique cover problem is NP-complete for cographs. We show that the
independent set problem on edge-clique graphs of cographs. We show that the
independent set problem on edge-clique graphs of graphs wit...

Fáry's theorem states that every plane graph can be drawn as a straight-line drawing. A plane graph is a graph embedded in a plane without edge cross-ings. In this paper, we extend Fáry's theorem to non-planar graphs. More specif-ically, we study the problem of drawing 1-plane graphs with straight-line edges. A 1-plane graph is a graph embedded in...

One of the most important and indispensable parameters of a Battery Management System (BMS) is to accurately estimate the State of Charge (SoC) of battery. Precise estimation of SoC can prevent battery from damage or premature aging by avoiding over charge or discharge. Due to the limited capacity of a battery, advanced methods must be used to esti...

Given a graph G and integers b and w. The black-and-white coloring problem
asks if there exist disjoint sets of vertices B and W with |B|=b and |W|=w such
that no two vertices x in B and y in W are adjacent. In this paper we show that
the problem is polynomial when restricted to permutation graphs and, more
generally, to circle graphs.

One of the most important and indispensable parameters of a Battery Management Systems (BMS) is accurate estimates of the State of Charge (SoC) of the battery. It can prevent battery from damage or premature aging by avoiding over charge/discharge. Due to the limited capacity of a battery, advanced methods must be used to estimate precisely the SoC...

Given a graph G and integers b and w. The black-and-white coloring problem
asks if there exist disjoint sets of vertices B and W with |B|=b and |W|=w such
that no vertex in B is adjacent to any vertex in W. In this paper we show that
the problem is polynomial when restricted to cographs, distance-hereditary
graphs, interval graphs and strongly chor...

We show that there exist linear-time algorithms that compute the strong
chromatic index of Halin graphs, of maximal outerplanar graphs and of
distance-hereditary graphs.

An edge dominating set of a graph G = (V,E) is a subset M ⊆ E of edges in the graph such that each edge in E − M is incident with at least one edge in M. In an instance of the parameterized edge dominating set problem we are given a graph G = (V,E) and an integer k and we are asked to decide whether G has an edge dominating set of size at most k. I...

In boundary labeling, each point site in a rectangular map is connected to a label outside the map by a leader, which may be a rectilinear or a straight-line segment. Among various types of leaders, the so-called type-opo leader consists of three segments (from the site to its associated label) that are orthogonal, then parallel, and then orthogona...

An edge dominating set of a graph G=(V,E) is a subset M of edges in the graph
such that each edge in E-M is incident with at least one edge in M. In an
instance of the parameterized edge dominating set problem we are given a graph
G=(V,E) and an integer k and we are asked to decide whether G has an edge
dominating set of size at most k. In this pap...

Let G=(A,B,E) be a bipartite graph with color classes A and B. The graph G is
chordal bipartite if G has no induced cycle of length more than four. Let
G=(V,E) be a graph. A feedback vertex set F is a set of vertices F subset V
such that G-F is a forest. The feedback vertex set problem asks for a feedback
vertex set of minimal cardinality. We show...

We show that there exist efficient algorithms for the triangle packing
problem in colored permutation graphs, complete multipartite graphs,
distance-hereditary graphs, k-modular permutation graphs and complements of
k-partite graphs (when k is fixed). We show that there is an efficient
algorithm for C_4-packing on bipartite permutation graphs and w...

The classical Fáry's theorem from the 1930s states that every planar graph can be drawn as a straight-line drawing. In this paper, we extend Fáry's the-orem to non-planar graphs. More specifically, we study the problem of drawing 1-planar graphs with straight-line edges. A 1-planar graph is a sparse non-planar graph with at most one crossing per ed...

The spanning ratio and maximum detour of a graph G embedded in a metric space measure how well G approximates the minimum complete graph containing G and metric space, respectively. In this paper we show that computing the spanning ratio of a rectilinear path P in L
1 space has a lower bound of Ω(n logn) in the algebraic computation tree model and...

We study the complexity of the problem of finding non-planar rectilinear drawings of graphs. This problem is known to be NP-complete.
We consider natural restrictions of this problem where constraints are placed on the possible orientations of edges. In particular,
we show that if each edge has prescribed direction “left”, “right”, “down” or “up”,...

In a balloon drawing of a tree, all the children under the same parent are placed on the circumference of the circle centered at their parent, and the radius of the circle centered at each node along any path from the root reflects the number of descendants associated with the node. Among various styles of tree drawings reported in the literature,...

Map labeling encounters unique issues in the context of dynamic maps with continuous zooming and panning---an application with increasing practical importance. In emphconsistent dynamic map labeling, distracting behavior such as popping and jumping is avoided. We use a model for consistent dynamic labeling in which a label is represented by a 3d-so...

This book constitutes the first part of the refereed proceedings of the Third International Conference, IC3 2010, held in Noida, India, in August 2010.
The 23 revised full papers presented were carefully reviewed and selected from numerous submissions.

A rectilinear drawing is an orthogonal grid drawing without bends, possibly with edge crossings, without any overlapping between edges, between vertices, or between edges and vertices. Rectilinear drawings without edge crossings (planar rectilinear drawings) have been extensively investigated in graph drawing. Testing rectilinear planarity of a gra...

Locked tree linkages have been known to exist in the plane since 1998, but it is still open whether they have a polynomial-time
characterization. This paper examines the properties needed for planar trees to lock, with a focus on finding the smallest
locked trees according to different measures of complexity, and suggests some new avenues of resear...

We consider the problems of straightening polygonal trees and convexifying polygons by continuous motions such that rigid edges can rotate around vertex joints and no edge crossings are allowed. A tree can be straightened if all its edges can be aligned along a common straight line such that each edge points “away” from a designated leaf node. A po...

We consider the problems of unfolding 3D lattice polygons embedded on the surface of some classes of lattice polyhedra, and
of unfolding 2D orthogonal trees. During the unfolding process, all graph edges are preserved and no edge crossings are allowed.
Let n be the number of edges of the given polygon or tree. We show that a lattice polygon embedde...

Map labeling encounters unique issues in the context of dynamic maps with continuous zooming and panning-an application with increasing practical importance. In consistent dynamic map labeling, distracting behavior such as popping and jumping is avoided. We use a model for consistent dynamic labeling in which a label is represented by a 3d-solid, w...

We consider the problem of unfolding lattice trees and polygons in hexagonal or triangular lattice in two di- mensions. We show that a hexagonal/triangular lattice chain (resp. tree) can be straightened in O(n) (resp. O(n2)) moves and time, and a hexagonal/triangular lat- tice polygon can be convexified in O(n2) moves and time. We hope that the tec...

We consider the problems of straightening polygonal trees and convexifying polygons by continuous motions such that rigid
edges can rotate around vertex joints and no edge crossings are allowed. A tree can be straightened if all its edges can be aligned along a common straight line such that each edge points “away” from a designated leaf node.
A po...

We design compact and responsive kinetic data structures for detecting collisions between n convex fat objects in 3-dimensional space that can have arbitrary sizes. Our main results are:
(i) If the objects are 3-dimensional balls that roll on a plane, then we can detect collisions with a KDS of size O(nlogn) that can handle events in O(logn) time....

A pants decomposition of an orientable surface S is a collection of simple cycles that partition S into pants, i.e., surfaces of genus zero with three boundary cycles. Given a set P of n points in the plane, we consider the problem of computing a pants decomposition of the surface S which is the plane minus P, of minimum total length. We give a pol...

We design compact and responsive kinetic data structures for detecting collisions between n convex fat objects in 3-dimensional space that can have arbitrary sizes. Our main results are: (i)
If the objects are 3-dimensional balls that roll on a plane, then we can detect collisions with a KDS of size O(nlog n) that can handle events in O(log 2n) tim...

We consider whether or not protein chains in the HP model have unique or few optimal foldings. We solve the conjecture proposed by Aichholzer et al. that the open chain L2k 1 = (HP)k(PH)k 1 for k 3 has ex- actly two optimal foldings on the square lattice. We show that some closed and open chains have unique optimal foldings on the hexagonal and tri...

A polygonal chain is a sequence of consecutively joined edges embedded in space. A k-chain is a chain of k edges. A polygonal tree is a set of edges joined into a tree structure embedded in space. A unit tree is a tree with only edges of unit length. A chain or a tree is simple if non-adjacent edges do not intersect.
We consider the problem about t...

A set of points shown on the map usually represents special sites like cities or towns in a country. If the map in the interactive geo- graphical information system (GIS) is browsed by users on the computer screen or on the web, the points and their labels can be viewed in a query window at dieren t resolutions by zooming in or out according to the...

We present an algorithm to reconstruct a collection of disjoint smooth closed curves from n noisy samples. Our noise model assumes that the samples are obtained by first drawing points on the curves according to a locally uniform distribution followed by a uniform perturbation of each point in the normal direction with a magnitude smaller than the...

We propose an algorithm to compute a conforming Delaunay mesh of a bounded domain in ℝ 3 specified by a piecewise linear complex. Arbitrarily small input angles are allowed, and the input complex is not required to be a manifold. Our algorithm encloses the input edges with a small buffer zone, a union of balls whose sizes are proportional to the lo...

Given a triangulated closed surface, the problem of constructing a hierarchy of surface models of decreasing level of detail has attracted much attention in computer graphics. A hierarchy provides view-dependent refinement and facilitates the computation of parameterization. For a triangulated closed surface of n vertices and genus g, we prove that...

Annotating maps, graphs, and diagrams with pieces of text is an important step in information visualization that is usually referred to as label placement. We define nine label-placement models for labeling points with axis-parallel rectangles given a weight for each point. There are two groups: fixed-position models and slider models. We aim to ma...

We present an algorithm to reconstruct a collection of disjoint smooth closed curves from n noisy samples. Our noise model assumes that the samples are obtained by first drawing points on the curves according to a locally uniform distribution followed by a uniform perturbation of each point in the normal direction with a magnitude smaller than the...

We propose an algorithm to compute a conforming Delaunay mesh of a polyhedral domain in three dimensions. Arbitrarily small input angles are allowed. The output mesh is graded and has bounded radius-edge ratio everywhere. 1

Given a triangulated closed surface, the problem of constructing a hierarchy of surface models of decreasing level of detail
has attracted much attention in computer graphics. A hierarchy provides view-dependent refinement and facilitates the computation
of parameterization. For a triangulated closed surface of n vertices and genus g, we prove that...

Annotating maps, graphs, and diagrams with pieces of text is an important step in information visualization that is usually referred to as label placement. We define nine label-placement models for labeling points with axis-parallel rectangles given a weight for each point. There are two groups; fixed-position models and slider models. We aim to ma...

Annotating maps, graphs, and diagrams with pieces of text is an important

We prove that there exists linearly many independent edge chains of length k in a connected orientable triangulated 2-manifold (possibly with boundary) of genus zero, for any positive integer parameter k. Such an independent set of chains can be identified by a simple linear-time algorithm. Our motivation is to simplify a surface by repeatedly cont...

We consider the problem of unfolding lattice polygons embedded on the surface of some classes of lattice polyhedra. We show that an unknotted lattice poly-gon embedded on a lattice orthotube or orthotree can be convexified in O(n) moves and time, and a lat-tice polygon embedded on a lattice Tower of Hanoi or Manhattan Tower can be convexified in O(...