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A Bayesian metamodeling approach for stochastic simulations

Jun Yin, Szu Hui Ng, Kien Ming Ng
2010 Proceedings of the 2010 Winter Simulation Conference  
, and Ng 2008) ).  ...  , and Ng 2009 ).  ... 
doi:10.1109/wsc.2010.5679086 dblp:conf/wsc/YinNN10 fatcat:b7qw5bretvdfnlwfuoeixcn7si

Solving The Teacher Assignment-Course Scheduling Problem By A Hybrid Algorithm

Aldy Gunawan, Kien Ming Ng, Kim Leng Poh
2007 Zenodo  
Kien Ming Ng is with the Department of Industrial and Systems Engineering, National University of Singapore, 1 Engineering Drive 2, S(117576), Singapore (e-mail: isenkm@nus.edu.sg).  ... 
doi:10.5281/zenodo.1076700 fatcat:qegxhmrr3vbipklliv5dufshby

Perturbation Based Search Method For Solving Unconstrained Binary Quadratic Programming Problem

Muthu Solayappan, Kien Ming Ng, Kim Leng Poh
2008 Zenodo  
Moreover, only medium sized Muthu Solayappan (muthu@nus.edu.sg), Kien Ming Ng (isenkm@nus.edu.sg) and Kim Leng Poh (isepohkl@nus.edu.sg) are with the Department of Industrial and Systems Engineering, National  ... 
doi:10.5281/zenodo.1081850 fatcat:r7o4c5esovci3mgil6cdagb5o4

An algorithm for nonlinear optimization problems with binary variables

Walter Murray, Kien-Ming Ng
2008 Computational optimization and applications  
One of the challenging optimization problems is determining the minimizer of a nonlinear programming problem that has binary variables. A vexing difficulty is the rate the work to solve such problems increases as the number of discrete variables increases. Any such problem with bounded discrete variables, especially binary variables, may be transformed to that of finding a global optimum of a problem in continuous variables. However, the transformed problems usually have astronomically large
more » ... bers of local minimizers, making them harder to solve than typical global optimization problems. Despite this apparent disadvantage, we show that the approach is not futile if we use smoothing techniques. The method we advocate first convexifies the problem and then solves a sequence of subproblems, whose solutions form a trajectory that leads to the solution. To illustrate how well the algorithm performs we show the computational results of applying it to problems taken from the literature and new test problems with known optimal solutions.
doi:10.1007/s10589-008-9218-1 fatcat:uj62ggkkczc2bmgygvhf4uv5fe

A study on the effects of parameter estimation on kriging model's prediction error in stochastic simulations

Jun Yin, Szu Hui Ng, Kien Ming Ng
2009 Proceedings of the 2009 Winter Simulation Conference (WSC)  
and Ng 2008) .  ...  One Dimension Quadratic Test Function The quadratic test function y=x 2 was used in Yin, Ng, and Ng (2008) .  ... 
doi:10.1109/wsc.2009.5429703 dblp:conf/wsc/YinNN09 fatcat:rn3mosyscbfklce3ggmnxvn5ku

A water-flow algorithm for flexible flow shop scheduling with intermediate buffers

Trung Hieu Tran, Kien Ming Ng
2010 Journal of Scheduling  
In this paper, we propose a water flow algorithm for solving flexible flow shop scheduling problem with limited intermediate buffers, which is a NP-hard problem encountered in industry. The proposed algorithm is inspired by the hydrological cycle in meteorology and the erosion phenomenon in nature. In the algorithm, we combine the amount of precipitation and its falling force to form a flexible erosion capability, which helps the erosion process focus on exploiting promising regions strongly.
more » ... also integrate a seed position obtained by a constructive algorithm into the initial population to increase the performance of the algorithm. Some benchmark instances of the scheduling problem are used to evaluate our proposed algorithm. The computational results and comparisons demonstrate the efficacy of the algorithm. In addition, an industrial example is also introduced to illustrate the algorithm's efficiency when solving practical problems.
doi:10.1007/s10951-010-0205-x fatcat:pq3vdcywzvd6rdfl5lljx6h7f4

Minimum Speed Seeking Control for Nonhovering Autonomous Underwater Vehicles

You Hong Eng, Mandar Chitre, Kien Ming Ng, Kwong Meng Teo
2015 Journal of Field Robotics  
Most autonomous underwater vehicles (AUVs) are propelled by a single thruster, use elevators and rudders as control surfaces, and are torpedo-shaped. Furthermore, they are positively buoyant to facilitate recovery during an emergency. For this class of nonhovering AUVs, there is a minimum speed at which the AUV must travel for stable depth control. Otherwise, the extra buoyancy will bring the AUV up to the surface when the fin loses its effectiveness at low speeds. Hence, we develop a novel
more » ... rithm such that the AUV is automatically controlled to travel at its minimum speed while maintaining a constant depth. This capability is important in a number of practical scenarios, including underwater loitering with minimum energy consumption, underwater docking with minimum impact, and high-resolution sensing at minimum speed. First, we construct a depth dynamic model to explain the mechanism of the minimum speed, and we show its relationship with the buoyancy, the righting moment, and the fin's effectiveness of the AUV. Next, we discuss the minimum speed seeking problem under the framework of extremum seeking. We extend the framework by introducing a new definition of steady-state mapping that imposes new structure on the seeking algorithm. The proposed algorithm employs a fuzzy inference system, which is driven by the real-time measurements of pitch error and elevator deflection. The effectiveness of the algorithm in seeking the minimum speed is validated in both simulations and field experiments. C 2015 Wiley Periodicals, Inc.
doi:10.1002/rob.21625 fatcat:gv4d7eqgifa3zhb7uy3est2ydu

A hybridized Lagrangian relaxation and simulated annealing method for the course timetabling problem

Aldy Gunawan, Kien Ming Ng, Kim Leng Poh
2012 Computers & Operations Research  
This paper describes a timetabling problem at universities, where a master course timetable is given extrinsically and conflicts due to students' course enrollment do not need to be considered. A solver for the problem, which integrates both teacher assignment and course scheduling, is described. An initial solution is obtained by a mathematical programming approach based on Lagrangian relaxation. This solution is further improved by a simulated annealing algorithm. The proposed method has been
more » ... tested on instances from a university in Indonesia, as well as on several randomly generated datasets, and the corresponding computational results are reported.
doi:10.1016/j.cor.2012.03.011 fatcat:iehz2xz3wbdvhjcx25ytrhign4

An iterated local search algorithm for the team orienteering problem with variable profits

Aldy Gunawan, Kien Ming Ng, Graham Kendall, Junhan Lai
2018 Engineering optimization (Print)  
The orienteering problem (OP) is a routing problem that has numerous applications in various domains such as logistics and tourism. The objective is to determine a subset of vertices to visit for a vehicle so that the total collected score is maximized and a given time budget is not exceeded. The extensive application of the OP has led to many different variants, including the team orienteering problem (TOP) and the team orienteering problem with time windows. The TOP extends the OP by
more » ... ng multiple vehicles. In this article, the team orienteering problem with variable profits (TOPVP) is studied. The main characteristic of the TOPVP is that the amount of score collected from a visited vertex depends on the duration of stay on that vertex. A mathematical programming model for the TOPVP is first presented and an algorithm based on iterated local search (ILS) that is able to solve modified benchmark instances is then proposed. It is concluded that ILS produces solutions which are comparable to those obtained by the commercial solver CPLEX for smaller instances. For the larger instances, ILS obtains good-quality solutions that have significantly better objective value than those found by CPLEX under reasonable computational times. ARTICLE HISTORY
doi:10.1080/0305215x.2017.1417398 fatcat:czxi7d76rzanblqur2xosn3eqe

Solving the Quadratic Assignment Problem by a Hybrid Algorithm

Aldy Gunawan, Kien Ming Ng, Kim Leng Poh
2011 International Journal on Advanced Science, Engineering and Information Technology  
This paper presents a hybrid algorithm to solve the Quadratic Assignment Problem (QAP). The proposed algorithm involves using the Greedy Randomized Adaptive Search Procedure (GRASP) to obtain an initial solution, and then using a combined Simulated Annealing (SA) and Tabu Search (TS) algorithm to improve the solution. Experimental results indicate that the hybrid algorithm is able to obtain good quality solutions for QAPLIB test problems within reasonable computation time.
doi:10.18517/ijaseit.1.1.10 fatcat:iadxtihd2zhqpie5twhvalz4te

A parallel water flow algorithm with local search for solving the quadratic assignment problem

Kien Ming Ng, Trung Hieu Tran
2017 Journal of Industrial and Management Optimization  
Tran and Ng [39] developed an algorithm based on the properties as well as behaviors of water flow, such as the simulation of raindrop distribution, the property of water flow always moving to lower  ...  WFA is a natureinspired algorithm, introduced by Tran and Ng [39] for solving certain types of combinatorial optimization problems such as the flexible flow shop scheduling problems with intermediate  ... 
doi:10.3934/jimo.2018041 fatcat:y57djrfambetbmtjvwsgoyakja

Hybrid metaheuristics for solving the quadratic assignment problem and the generalized quadratic assignment problem

Aldy Gunawan, Kien Ming Ng, Kim Leng Poh, Hoong Chuin Lau
2014 2014 IEEE International Conference on Automation Science and Engineering (CASE)  
One Hybrid Metaheuristics for Solving the Quadratic Assignment Problem and the Generalized Quadratic Assignment ProblemAldy Gunawan, Kien Ming Ng, Kim Leng Poh and Hoong Chuin Lau ij f  ] and C΄ =  ... 
doi:10.1109/coase.2014.6899314 dblp:conf/case/GunawanNPL14 fatcat:kucpzvznjzg6tbkzq3dunhwqsy

The Gastric Microbiome of Four Malaysian Gastroduodenal Disease Patients

Khosravi Yalda, Gan Han Ming, Chia Patrick Jing Yi, Croft Larry J, Ng Chow Goon, Goh Khean Lee, Vellasamy Kumutha Malar, Mariappan Vanitha, Ong Kien Chai, Wong Kum Thong, Loke Mun Fai, Vadivelu Jamuna
2017 Archives of Gene and Genome Research  
causing melioidosis, we postulate that the bacterium might be part of the gastric microbiome of people from places endemic for B. pseudo- Shotgun metagenomics Despite that next-generation sequencing (NGS  ... 
doi:10.36959/998/781 fatcat:ba4qq5r6wvdj5ig2rbynjzf3qu

Effect of Rare Earth Elements Substitution in La site for LaMnO 3 Manganites

Jen Wong, Kuen, Kean Lim, Abdul Pah, Chen Shaari, Ng Kien, Wei Siau, Albert Gan, Han Ming
2012 Pertanika J. Sci. & Technol   unpublished
With a view to understanding the effect of rare earth element (Ce, Pr, Nd, Sm and Gd) substitution for the La site in LaMnO 3 (LMO), the samples were prepared via solid-state reaction. Structure investigation by X-ray diffraction (XRD) showed that structure transformation from trigonal (LMO) to orthorhombic (PMO, NMO, SMO and GMO) occurred when smaller trivalent rare earth element was replaced. The MnO 6 octahedra were tilted and elongated or compressed, corresponding to the ionic radii of the
more » ... are earth inserted. Meanwhile, microstructure study using scanning electron microscopy (SEM) illustrated that La substitution by another rare earth element caused a reduction in grain size. This might due to the changes in enthalpy of fusion by other rare earth ions, where higher enthalpy of fusion favours formation of smaller grain size. However, CeMnO 3 did not form under this preparation condition. The magnetic properties studied from the hysteresis plot taken at room temperature indicated that the substitution of La with other magnetic trivalent rare earth ions strongly weakened the magnetic strength of the system.
fatcat:7ye57syzrzcrfndqidrv3fey2e

Le Royaume de Champa

Georges Maspero
1910 T'oung pao (Print)  
Dans le Leang Chou LIV 54a, et le Sk ng V 2a, lisez Iliao Kien $fi §fl § pour Kien Yuan §fl § Lean,g Chou LIV 54a. Nan Che LXXVIII 41b. Sk ng V 2a.  ...  Pendant les pgriodes "Hiao Kien, 454 -56, et Ta Ming... , le roi de Lin-Yi, Fan Chen Tchcng envoya...."porter le tribut.... Pendant la periode Yang Ming 4S3-493 . ....  ... 
doi:10.1163/156853210x00289 fatcat:uu4jq4hqt5bg3c5noeegt3o6ae
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