# Wayan F. Mahmudy

## Publications

##### 5 Modeling and Optimization of Part Type Selection and Loading Problem in Flexible Manufacturing System Using Real Coded Genetic Algorithms

**Authors:**
Wayan F. Mahmudy,
Romeo M. Marian,
Lee H. S. Luong

**Abstract:**

This paper deals with modeling and optimization of two NP-hard problems in production planning of flexible manufacturing system (FMS), part type selection problem and loading problem. The part type selection problem and the loading problem are strongly related and heavily influence the system’s efficiency and productivity. These problems have been modeled and solved simultaneously by using real coded genetic algorithms (RCGA) which uses an array of real numbers as chromosome representation. The novel proposed chromosome representation produces only feasible solutions which minimize a computational time needed by GA to push its population toward feasible search space or repair infeasible chromosomes. The proposed RCGA improves the FMS performance by considering two objectives, maximizing system throughput and maintaining the balance of the system (minimizing system unbalance). The resulted objective values are compared to the optimum values produced by branch-and-bound method. The experiments show that the proposed RCGA could reach near optimum solutions in a reasonable amount of time.

**Keywords:**
Production Planning,
real-coded genetic algorithm,
flexible manufacturing system,
part type selection problem,
loading problem

##### 4 Parallel Text Processing: Alignment of Indonesian to Javanese Language

**Authors:**
Wayan F. Mahmudy,
Aji P. Wibawa,
Andrew Nafalski,
Neil Murray

**Abstract:**

Parallel text alignment is proposed as a way of aligning *bahasa Indonesia* to words in Javanese. Since the one-to-one word translator does not have the facility to translate pragmatic aspects of Javanese, the parallel text alignment model described uses a phrase pair combination. The algorithm aligns the parallel text automatically from the beginning to the end of each sentence. Even though the results of the phrase pair combination outperform the previous algorithm, it is still inefficient. Recording all possible combinations consume more space in the database and time consuming. The original algorithm is modified by applying the edit distance coefficient to improve the data-storage efficiency. As a result, the data-storage consumption is 90% reduced as well as its learning period (42s).

**Keywords:**
edit distance coefficient,
phrase pair combination,
Parallel text alignment,
Javanese-Indonesian language

##### 3 Solving Part Type Selection and Loading Problem in Flexible Manufacturing System Using Real Coded Genetic Algorithms – Part II: Optimization

**Authors:**
Wayan F. Mahmudy,
Romeo M. Marian,
Lee H. S. Luong

**Abstract:**

This paper presents modeling and optimization of two NP-hard problems in flexible manufacturing system (FMS), part type selection problem and loading problem. Due to the complexity and extent of the problems, the paper was split into two parts. The first part of the papers has discussed the modeling of the problems and showed how the real coded genetic algorithms (RCGA) can be applied to solve the problems. This second part discusses the effectiveness of the RCGA which uses an array of real numbers as chromosome representation. The novel proposed chromosome representation produces only feasible solutions which minimize a computational time needed by GA to push its population toward feasible search space or repair infeasible chromosomes. The proposed RCGA improves the FMS performance by considering two objectives, maximizing system throughput and maintaining the balance of the system (minimizing system unbalance). The resulted objective values are compared to the optimum values produced by branch-and-bound method. The experiments show that the proposed RCGA could reach near optimum solutions in a reasonable amount of time.

**Keywords:**
Production Planning,
flexible manufacturing system,
part type selection problem,
loading problem,
real-coded genetic
algorithm

##### 2 Edit Distance Algorithm to Increase Storage Efficiency of Javanese Corpora

**Authors:**
Wayan F. Mahmudy,
Aji P. Wibawa,
Andrew Nafalski,
Neil Murray

**Abstract:**

**Keywords:**
edit distance coefficient,
Javanese,
parallel text
alignment,
phrase pair combination

##### 1 Solving Part Type Selection and Loading Problem in Flexible Manufacturing System Using Real Coded Genetic Algorithms – Part I: Modeling

**Authors:**
Wayan F. Mahmudy,
Romeo M. Marian,
Lee H. S. Luong

**Abstract:**

**Keywords:**
Production Planning,
flexible manufacturing system,
part type selection problem,
loading problem,
real-coded genetic
algorithm