**Commenced**in January 2007

**Frequency:**Monthly

**Edition:**International

**Paper Count:**476

# Search results for: Ill-posed problem

##### 476 ATM Location Problem and Cash Management in Automated Teller Machines

**Authors:**
M. Erol Genevois,
D. Celik,
H. Z. Ulukan

**Abstract:**

**Keywords:**
ATM location problem,
cash management problem,
ATM cash replenishment problem,
literature review in ATMs.

##### 475 Bi-linear Complementarity Problem

**Authors:**
Chao Wang,
Ting-Zhu Huang Chen Jia

**Abstract:**

In this paper, we propose a new linear complementarity problem named as bi-linear complementarity problem (BLCP) and the method for solving BLCP. In addition, the algorithm for error estimation of BLCP is also given. Numerical experiments show that the algorithm is efficient.

**Keywords:**
Bi-linear complementarity problem,
Linear complementarity
problem,
Extended linear complementarity problem,
Error
estimation,
P-matrix,
M-matrix.

##### 474 A New Heuristic Approach for the Large-Scale Generalized Assignment Problem

**Authors:**
S. Raja Balachandar,
K.Kannan

**Abstract:**

This paper presents a heuristic approach to solve the Generalized Assignment Problem (GAP) which is NP-hard. It is worth mentioning that many researches used to develop algorithms for identifying the redundant constraints and variables in linear programming model. Some of the algorithms are presented using intercept matrix of the constraints to identify redundant constraints and variables prior to the start of the solution process. Here a new heuristic approach based on the dominance property of the intercept matrix to find optimal or near optimal solution of the GAP is proposed. In this heuristic, redundant variables of the GAP are identified by applying the dominance property of the intercept matrix repeatedly. This heuristic approach is tested for 90 benchmark problems of sizes upto 4000, taken from OR-library and the results are compared with optimum solutions. Computational complexity is proved to be O(mn2) of solving GAP using this approach. The performance of our heuristic is compared with the best state-ofthe- art heuristic algorithms with respect to both the quality of the solutions. The encouraging results especially for relatively large size test problems indicate that this heuristic approach can successfully be used for finding good solutions for highly constrained NP-hard problems.

**Keywords:**
Combinatorial Optimization Problem,
Generalized Assignment Problem,
Intercept Matrix,
Heuristic,
Computational Complexity,
NP-Hard Problems.

##### 473 A Method for Solving a Bi-Objective Transportation Problem under Fuzzy Environment

**Authors:**
Sukhveer Singh,
Sandeep Singh

**Abstract:**

A bi-objective fuzzy transportation problem with the objectives to minimize the total fuzzy cost and fuzzy time of transportation without according priorities to them is considered. To the best of our knowledge, there is no method in the literature to find efficient solutions of the bi-objective transportation problem under uncertainty. In this paper, a bi-objective transportation problem in an uncertain environment has been formulated. An algorithm has been proposed to find efficient solutions of the bi-objective transportation problem under uncertainty. The proposed algorithm avoids the degeneracy and gives the optimal solution faster than other existing algorithms for the given uncertain transportation problem.

**Keywords:**
Transportation problem,
efficient solution,
ranking function,
fuzzy transportation problem.

##### 472 Creative Thinking Skill Approach Through Problem-Based Learning: Pedagogy and Practice in the Engineering Classroom

**Authors:**
Halizah Awang,
Ishak Ramly

**Abstract:**

**Keywords:**
Creative Thinking Skills,
Problem-based Learning,
Problem Solving.

##### 471 Vehicle Routing Problem with Mixed Fleet of Conventional and Heterogenous Electric Vehicles and Time Dependent Charging Costs

**Authors:**
Ons Sassi,
Wahiba Ramdane Cherif-Khettaf,
Ammar Oulamara

**Abstract:**

In this paper, we consider the vehicle routing problem with mixed fleet of conventional and heterogenous electric vehicles and time dependent charging costs, denoted VRP-HFCC, in which a set of geographically scattered customers have to be served by a mixed fleet of vehicles composed of a heterogenous fleet of Electric Vehicles (EVs), having different battery capacities and operating costs, and Conventional Vehicles (CVs). We include the possibility of charging EVs in the available charging stations during the routes in order to serve all customers. Each charging station offers charging service with a known technology of chargers and time dependent charging costs. Charging stations are also subject to operating time windows constraints. EVs are not necessarily compatible with all available charging technologies and a partial charging is allowed. Intermittent charging at the depot is also allowed provided that constraints related to the electricity grid are satisfied. The objective is to minimize the number of employed vehicles and then minimize the total travel and charging costs. In this study, we present a Mixed Integer Programming Model and develop a Charging Routing Heuristic and a Local Search Heuristic based on the Inject-Eject routine with different insertion methods. All heuristics are tested on real data instances.

**Keywords:**
charging problem,
electric vehicle,
heuristics,
local
search,
optimization,
routing problem.

##### 470 A New Heuristic Algorithm for the Classical Symmetric Traveling Salesman Problem

**Authors:**
S. B. Liu,
K. M. Ng,
H. L. Ong

**Abstract:**

**Keywords:**
Local search,
overlapped neighborhood,
travelingsalesman problem.

##### 469 Research on Self-Perceptions of Pre-Service Turkish Language Teachers in Turkey with Regard to Problem Solving Skills

**Authors:**
Canan Aslan

**Abstract:**

The aim of this research is to determine how preservice Turkish teachers perceive themselves in terms of problem solving skills. Students attending Department of Turkish Language Teaching of Gazi University Education Faculty in 2005-2006 academic year constitute the study group (n= 270) of this research in which survey model was utilized. Data were obtained by Problem Solving Inventory developed by Heppner & Peterson and Personal Information Form. Within the settings of this research, Cronbach Alpha reliability coefficient of the scale was found as .87. Besides, reliability coefficient obtained by split-half technique which splits odd and even numbered items of the scale was found as r=.81 (Split- Half Reliability). The findings of the research revealed that preservice Turkish teachers were sufficiently qualified on the subject of problem solving skills and statistical significance was found in favor of male candidates in terms of “gender" variable. According to the “grade" variable, statistical significance was found in favor of 4th graders.

**Keywords:**
Problem Solving,
problem solving skills,
PreserviceTurkish Language Teachers.

##### 468 Seat Assignment Problem Optimization

**Authors:**
Mohammed Salem Alzahrani

**Abstract:**

**Keywords:**
Assignment Problem,
Hungarian Method,
Least Cost
Method,
Northwest Corner Method,
Seat Assignment Method
(SAM),
A Real Word Assignment Problem.

##### 467 The Locker Problem with Empty Lockers

**Authors:**
David Avis,
Luc Devroye,
Kazuo Iwama

**Abstract:**

We consider a cooperative game played by n players against a referee. The players names are randomly distributed among n lockers, with one name per locker. Each player can open up to half the lockers and each player must find his name. Once the game starts the players may not communicate. It has been previously shown that, quite surprisingly, an optimal strategy exists for which the success probability is never worse than 1 − ln 2 ≈ 0.306. In this paper we consider an extension where the number of lockers is greater than the number of players, so that some lockers are empty. We show that the players may still win with positive probability even if there are a constant k number of empty lockers. We show that for each fixed probability p, there is a constant c so that the players can win with probability at least p if they are allowed to open cn lockers.

**Keywords:**
Locker problem,
pointer-following algorithms.

##### 466 Avoiding Pin Ball Routing Problem in Network Mobility Hand-Off Management

**Authors:**
M. Dinakaran,
P. Balasubramanie

**Abstract:**

**Keywords:**
Mobile IP,
Pinball routing problem,
NEMO

##### 465 The Effect of Peer Support to Interpersonal Problem Solving Tendencies and Skills in Nursing Students

**Authors:**
B. Özlük,
A. Karaaslan

**Abstract:**

This study has been conducted as a supplementary and relationship seeking study with the purpose of measuring the tendency and success of support among peers amid nursing students studying at university in solving interpersonal problems. The population of the study (N:279) is comprised of nursing students who are studying at one state and one private university in the province of Konya, while its sample is comprised of 231 nursing students who agreed to take part in the study voluntarily. As a result of this study, it has been determined that the peer support and interpersonal problem solving characteristics among students were at medium levels and that the interpersonal problem solving skills of students studying in the third year were higher than those of first and second year students. While the interpersonal problem solving characteristics of students who are aged 20 and over were found to be higher, no difference could be determined in terms of the interpersonal problem solving skills and tendencies among students, based on their gender and where they reside. A positive – to a medium degree – and significant relationship was determined between peer support and interpersonal problem solving skills, and it is possible to say that as peer support increases, so do the skills and tendencies to solve problems.

**Keywords:**
Interpersonal problem,
nursing students,
peer support,
problem solving.

##### 464 How to Build and Evaluate a Solution Method: An Illustration for the Vehicle Routing Problem

**Authors:**
Nicolas Zufferey

**Abstract:**

The vehicle routing problem (VRP) is a famous combinatorial optimization problem. Because of its well-known difficulty, metaheuristics are the most appropriate methods to tackle large and realistic instances. The goal of this paper is to highlight the key ideas for designing VRP metaheuristics according to the following criteria: efficiency, speed, robustness, and ability to take advantage of the problem structure. Such elements can obviously be used to build solution methods for other combinatorial optimization problems, at least in the deterministic field.

**Keywords:**
Vehicle routing problem,
Metaheuristics,
Combinatorial optimization.

##### 463 Iterative Methods for An Inverse Problem

**Authors:**
Minghui Wang,
Shanrui Hu

**Abstract:**

An inverse problem of doubly center matrices is discussed. By translating the constrained problem into unconstrained problem, two iterative methods are proposed. A numerical example illustrate our algorithms.

**Keywords:**
doubly center matrix,
electric network theory,
iterative methods,
least-square problem.

##### 462 An Agent-Based Approach to Vehicle Routing Problem

**Authors:**
Dariusz Barbucha,
Piotr Jedrzejowicz

**Abstract:**

The paper proposes and validates a new method of solving instances of the vehicle routing problem (VRP). The approach is based on a multiple agent system paradigm. The paper contains the VRP formulation, an overview of the multiple agent environment used and a description of the proposed implementation. The approach is validated experimentally. The experiment plan and the discussion of experiment results follow.

**Keywords:**
multi-agent systems,
population-based methods,
vehiclerouting problem.

##### 461 The Design of Axisymmetric Ducts for Incompressible Flow with a Parabolic Axial Velocity Inlet Profile

**Authors:**
V.Pavlika

**Abstract:**

In this paper a numerical algorithm is described for solving the boundary value problem associated with axisymmetric, inviscid, incompressible, rotational (and irrotational) flow in order to obtain duct wall shapes from prescribed wall velocity distributions. The governing equations are formulated in terms of the stream function ψ (x,y)and the function φ (x,y)as independent variables where for irrotational flow φ (x,y)can be recognized as the velocity potential function, for rotational flow φ (x,y)ceases being the velocity potential function but does remain orthogonal to the stream lines. A numerical method based on the finite difference scheme on a uniform mesh is employed. The technique described is capable of tackling the so-called inverse problem where the velocity wall distributions are prescribed from which the duct wall shape is calculated, as well as the direct problem where the velocity distribution on the duct walls are calculated from prescribed duct geometries. The two different cases as outlined in this paper are in fact boundary value problems with Neumann and Dirichlet boundary conditions respectively. Even though both approaches are discussed, only numerical results for the case of the Dirichlet boundary conditions are given. A downstream condition is prescribed such that cylindrical flow, that is flow which is independent of the axial coordinate, exists.

**Keywords:**
Inverse problem,
irrotational incompressible flow,
Boundary value problem.

##### 460 DNA Computing for an Absolute 1-Center Problem: An Evolutionary Approach

**Authors:**
Zuwairie Ibrahim,
Yusei Tsuboi,
Osamu Ono,
Marzuki Khalid

**Abstract:**

**Keywords:**
DNA computing,
operation research,
1-center
problem.

##### 459 The Low-fertility problem in Hong Kong: Do Mainlanders- Births Help to Rejuvenate Low-fertility Problem?

**Authors:**
Nancy,
Ling Sze Leung

**Abstract:**

Hong Kong is one of the regions in the world where Total Fertility Rate (TFR) is very low. In 2001, the TFR dropped until 0.931, which means 1 woman even cannot give birth to one child on average. However, after the reformation of the 'Right of Abode of Hong Kong' in 2001 and the Chinese Central Government loosened the disembarkation procedure of mainland Chinese (mainlander) to enter Hong Kong in 2003; mainlander couples started to cross the border for giving births in Hong Kong. This action raises Hong Kong-s TFR quickly from 0.931 (2001) to 1.094 (2010). Usually, an increasing trend of TFR means a sign of rejuvenation in low-fertility, but in the case of Hong Kong, the increase of TFR does not, rather it generates other population problems. This paper is going to discuss do mainlanders- births help to solve the low-fertility problem in Hong Kong.

**Keywords:**
Cross Border Birth,
Low-fertility,
Mainlander,
Total
Fertility Rate

##### 458 A Hybridization of Constructive Beam Search with Local Search for Far From Most Strings Problem

**Authors:**
Sayyed R Mousavi

**Abstract:**

The Far From Most Strings Problem (FFMSP) is to obtain a string which is far from as many as possible of a given set of strings. All the input and the output strings are of the same length, and two strings are said to be far if their hamming distance is greater than or equal to a given positive integer. FFMSP belongs to the class of sequences consensus problems which have applications in molecular biology. The problem is NP-hard; it does not admit a constant-ratio approximation either, unless P = NP. Therefore, in addition to exact and approximate algorithms, (meta)heuristic algorithms have been proposed for the problem in recent years. On the other hand, in the recent years, hybrid algorithms have been proposed and successfully used for many hard problems in a variety of domains. In this paper, a new metaheuristic algorithm, called Constructive Beam and Local Search (CBLS), is investigated for the problem, which is a hybridization of constructive beam search and local search algorithms. More specifically, the proposed algorithm consists of two phases, the first phase is to obtain several candidate solutions via the constructive beam search and the second phase is to apply local search to the candidate solutions obtained by the first phase. The best solution found is returned as the final solution to the problem. The proposed algorithm is also similar to memetic algorithms in the sense that both use local search to further improve individual solutions. The CBLS algorithm is compared with the most recent published algorithm for the problem, GRASP, with significantly positive results; the improvement is by order of magnitudes in most cases.

**Keywords:**
Bioinformatics,
Far From Most Strings Problem,
Hybrid metaheuristics,
Matheuristics,
Sequences consensus problems.

##### 457 Augmented Reality for Maintenance Operator for Problem Inspections

**Authors:**
Chong-Yang Qiao,
Teeravarunyou Sakol

**Abstract:**

**Keywords:**
Augmented reality,
situation awareness,
decision-making,
problem-solving.

##### 456 The Inverse Problem of Nonsymmetric Matrices with a Submatrix Constraint and its Approximation

**Authors:**
Yongxin Yuan,
Hao Liu

**Abstract:**

In this paper, we first give the representation of the general solution of the following least-squares problem (LSP): Given matrices X ∈ Rn×p, B ∈ Rp×p and A0 ∈ Rr×r, find a matrix A ∈ Rn×n such that XT AX − B = min, s. t. A([1, r]) = A0, where A([1, r]) is the r×r leading principal submatrix of the matrix A. We then consider a best approximation problem: given an n × n matrix A˜ with A˜([1, r]) = A0, find Aˆ ∈ SE such that A˜ − Aˆ = minA∈SE A˜ − A, where SE is the solution set of LSP. We show that the best approximation solution Aˆ is unique and derive an explicit formula for it. Keyw

**Keywords:**
Inverse problem,
Least-squares solution,
model updating,
Singular value decomposition (SVD),
Optimal approximation.

##### 455 Solutions of Fuzzy Transportation Problem Using Best Candidates Method and Different Ranking Techniques

**Authors:**
M. S. Annie Christi

**Abstract:**

Transportation Problem (TP) is based on supply and demand of commodities transported from one source to the different destinations. Usual methods for finding solution of TPs are North-West Corner Rule, Least Cost Method Vogel’s Approximation Method etc. The transportation costs tend to vary at each time. We can use fuzzy numbers which would give solution according to this situation. In this study the Best Candidate Method (BCM) is applied. For ranking Centroid Ranking Technique (CRT) and Robust Ranking Technique have been adopted to transform the fuzzy TP and the above methods are applied to EDWARDS Vacuum Company, Crawley, in West Sussex in the United Kingdom. A Comparative study is also given**.** We see that the transportation cost can be minimized by the application of CRT under BCM.

**Keywords:**
Best candidates method,
centroid ranking technique,
robust ranking technique,
transportation problem,
fuzzy transportation problem.

##### 454 The Multi-scenario Knapsack Problem: An Adaptive Search Algorithm

**Authors:**
Mhand Hifi,
Hedi Mhalla,
Mustapha Michaphy

**Abstract:**

In this paper, we study the multi-scenario knapsack problem, a variant of the well-known NP-Hard single knapsack problem. We investigate the use of an adaptive algorithm for solving heuristically the problem. The used method combines two complementary phases: a size reduction phase and a dynamic 2- opt procedure one. First, the reduction phase applies a polynomial reduction strategy; that is used for reducing the size problem. Second, the adaptive search procedure is applied in order to attain a feasible solution Finally, the performances of two versions of the proposed algorithm are evaluated on a set of randomly generated instances.

**Keywords:**
combinatorial optimization,
max-min optimization,
knapsack,
heuristics,
problem reduction

##### 453 Investigating Feed Mix Problem Approaches: An Overview and Potential Solution

**Authors:**
Rosshairy Abd Rahman,
Chooi-Leng Ang,
Razamin Ramli

**Abstract:**

Feed is one of the factors which play an important role in determining a successful development of an aquaculture industry. It is always critical to produce the best aquaculture diet at a minimum cost in order to trim down the operational cost and gain more profit. However, the feed mix problem becomes increasingly difficult since many issues need to be considered simultaneously. Thus, the purpose of this paper is to review the current techniques used by nutritionist and researchers to tackle the issues. Additionally, this paper introduce an enhance algorithm which is deemed suitable to deal with all the issues arise. The proposed technique refers to Hybrid Genetic Algorithm which is expected to obtain the minimum cost diet for farmed animal, while satisfying nutritional requirements. Hybrid GA technique with artificial bee algorithm is expected to reduce the penalty function and provide a better solution for the feed mix problem.

**Keywords:**
Artificial bee algorithm,
feed mix problem,
hybrid genetic algorithm.

##### 452 Public Key Cryptosystem based on Number Theoretic Transforms

**Authors:**
C. Porkodi,
R. Arumuganathan

**Abstract:**

**Keywords:**
Cryptography,
decryption,
discrete logarithm
problem encryption,
Integer Factorization problem,
Key agreement,
Number Theoretic Transform.

##### 451 Existence of Positive Solutions for Second-Order Difference Equation with Discrete Boundary Value Problem

**Authors:**
Thanin Sitthiwirattham,
Jiraporn Reunsumrit

**Abstract:**

We study the existence of positive solutions to the three points difference-summation boundary value problem. We show the existence of at least one positive solution if f is either superlinear or sublinear by applying the fixed point theorem due to Krasnoselskii in cones.

**Keywords:**
Positive solution,
Boundary value problem,
Fixed
point theorem,
Cone.

##### 450 Loudspeaker Parameters Inverse Problem for Improving Sound Frequency Response Simulation

**Authors:**
Y. T. Tsai,
Jin H. Huang

**Abstract:**

The sound pressure level (SPL) of the moving-coil loudspeaker (MCL) is often simulated and analyzed using the lumped parameter model. However, the SPL of a MCL cannot be simulated precisely in the high frequency region, because the value of cone effective area is changed due to the geometry variation in different mode shapes, it is also related to affect the acoustic radiation mass and resistance. Herein, the paper presents the inverse method which has a high ability to measure the value of cone effective area in various frequency points, also can estimate the MCL electroacoustic parameters simultaneously. The proposed inverse method comprises the direct problem, adjoint problem, and sensitivity problem in collaboration with nonlinear conjugate gradient method. Estimated values from the inverse method are validated experimentally which compared with the measured SPL curve result. Results presented in this paper not only improve the accuracy of lumped parameter model but also provide the valuable information on loudspeaker cone design.

**Keywords:**
Inverse problem,
cone effective area,
loudspeaker,
nonlinear conjugate gradient method.

##### 449 Solving the Teacher Assignment-Course Scheduling Problem by a Hybrid Algorithm

**Authors:**
Aldy Gunawan,
Kien Ming Ng,
Kim Leng Poh

**Abstract:**

This paper presents a hybrid algorithm for solving a timetabling problem, which is commonly encountered in many universities. The problem combines both teacher assignment and course scheduling problems simultaneously, and is presented as a mathematical programming model. However, this problem becomes intractable and it is unlikely that a proven optimal solution can be obtained by an integer programming approach, especially for large problem instances. A hybrid algorithm that combines an integer programming approach, a greedy heuristic and a modified simulated annealing algorithm collaboratively is proposed to solve the problem. Several randomly generated data sets of sizes comparable to that of an institution in Indonesia are solved using the proposed algorithm. Computational results indicate that the algorithm can overcome difficulties of large problem sizes encountered in previous related works.

**Keywords:**
Timetabling problem,
mathematical programming
model,
hybrid algorithm,
simulated annealing.

##### 448 Solving Stochastic Eigenvalue Problem of Wick Type

**Authors:**
Hassan Manouzi,
Taous-Meriem Laleg-Kirati

**Abstract:**

In this paper we study mathematically the eigenvalue problem for stochastic elliptic partial differential equation of Wick type. Using the Wick-product and the Wiener-Itô chaos expansion, the stochastic eigenvalue problem is reformulated as a system of an eigenvalue problem for a deterministic partial differential equation and elliptic partial differential equations by using the Fredholm alternative. To reduce the computational complexity of this system, we shall use a decomposition method using the Wiener-Itô chaos expansion. Once the approximation of the solution is performed using the finite element method for example, the statistics of the numerical solution can be easily evaluated.

**Keywords:**
Eigenvalue problem,
Wick product,
SPDEs,
finite
element,
Wiener-Itô chaos expansion.

##### 447 The Emoji Method: An Approach for Identifying and Formulating Problem Ideas

**Authors:**
Thorsten Herrmann,
Alexander Laukemann,
Hansgeorg Binz,
Daniel Roth

**Abstract:**

For the analysis of already identified and existing problems, the pertinent literature provides a comprehensive collection of approaches as well as methods in order to analyze the problems in detail. But coming up with problems, which are assets worth pursuing further, is often challenging. However, the importance of well-formulated problem ideas and their influence of subsequent creative processes are incontestable and proven. In order to meet the covered challenges, the Institute for Engineering Design and Industrial Design (IKTD) developed the Emoji Method. This paper presents the Emoji Method, which support designers to generate problem ideas in a structured way. Considering research findings from knowledge management and innovation management, research into emojis and emoticons reveal insights by means of identifying and formulating problem ideas within the early design phase. The simple application and the huge supporting potential of the Emoji Method within the early design phase are only few of the many successful results of the conducted evaluation. The Emoji Method encourages designers to identify problem ideas and describe them in a structured way in order to start focused with generating solution ideas for the revealed problem ideas.

**Keywords:**
Emojis,
problem ideas,
innovation management,
knowledge management.