Bottleneck adjacent matching heuristics for scheduling a re-entrant flow shop with dominant machine problem

The re-entrant flow shop environment has become prominent in the manufacturing industries and has recently attracted researchers attention. Typical examples of re-entrant flow shops are the printed circuit board manufacturing and furniture painting processes where components or processed parts enter some specific machines more than once. Similar with other manufacturing environment, identifying appropriate scheduling methodologies to ensure high output rate is very much desirable. The problem explored and investigated in this research is a special type of scheduling problem found in a re-entrant flow shop where two of its processes have high tendency of exhibiting bottleneck characteristics. The scheduling problem resembles a four machine permutation re-entrant flow shop with the routing of M1,M2,M3,M4,M3,M4 where Ml and M4 have high tendency of being the dominant machines. The main objective of this research is to take advantage of the bottleneck characteristics at the re-entrant flow shop and use it to develop heuristics that can be used to solve its scheduling problems. There are four major concentrations in this research. First, basic mathematical properties or conditions that explain the behaviour of the bottleneck processes were developed to give an insight and clearer understanding of the re-entrant flow shop with dominant machines. Second, four new and effective scheduling procedures which were called BAM1 (Bottleneck Adjacent Matching 1), BAM2, BAM3 and BAM4 heuristics were developed. Third, bottleneck approach was utilised in the study and the analysis using Visual Basic macro programming indicated that this method produced good results. Fourth, the Bottleneck Scheduling Performance (BSP) indexes introduced in the BAM heuristics procedure could be used to ascertain that some specific generated job arrangements are the optimum schedule. As a general conclusion, this research has achieved the objectives to develop bottleneck-based makespan algorithms and heuristics applicable for re-entrant flow shop environment. The experimental results demonstrated that the BAM heuristics generated good performances within specific P1 (first process) bottleneck dominance level and when the number of jobs increases. Within the medium to large-sized problems, BAM2 is the best at weak PI dominance level whereas BAM4 is the best at strong P1 dominance level

ARENA simulation training guideline for assembly line

As a beginner for the unfamiliar software such as Arena Simulation, it is very tough when we need to do a simple model by referring to the textbooks or journal articles that contains a lot of difficult words to understand. Therefore, a guideline was created to solve this problem that contains simple wordings, more infographic and the simple step by step procedures that are easy to follow, understand and to help the users. The purpose of the study was to build a training guideline for modeling an assembly line by using Arena Simulation, to build a model representing the assembly process using the training guide, and analyze the simulation result for the assembly line model. The study was conducted using Arena Simulation software. The data was collected based on the actual model to be inserted into the system setting for validation purposes. The model was created with 32 hours replications length to achieve accuracy in the result. The difference between the actual and simulation model must be below 5% percent to said the model is valid. To verify the guideline is applicable we build another example of the model and compared the simulation result with the actual simulation data from the textbook. To validate the model, we calculated the percentage difference between the actual and simulation model results. This simulation finding indicated that the guideline is suitable to be used as a learning tool and reference for users to model an assembly line. To conclude, this project has successfully provide a basic guideline for modelling an assembly line using Arena software and there is still a lot of rooms for future improvement

A study on energy (thermal) efficient aquaculture buildings for recirculating tank system / Sabarinah Sh Ahmad, Mohd Salleh Kamaruddin and Elias Salleh

Malaysia plans to increase in its annual aquaculture production to 662,000 tons by year 2015 from the current 200,000 tons. Almost all of these culture systems release untreated effluents and wastes directly into the natural bodies especially coastal waters. This practice has resulted in many environmental problems. It has also affected the quality of culture water especially among the shrimp and marine fish (cage) farmers as the aquaculture effluents accumulated over the years deteriorate the quality of the surrounding waters which is the source of water input. An FAO study shows that upto 79% dietary N and 85% dietary P inputs in a fish cage culture system are lost into the surrounding waters. To sustain a healthy and environmental friendly aquaculture development in Malaysia, intensive recirculating tank systems have to be used. These systems are expected to become increasingly important especially in freshwater aquaculture where the industry has to compete for limited water resource with other agricultural activities, industrial and domestic users. The Ministry of Agriculture and Agro-based Industries (MoA) have started pilot projects in Kedah, Sarawak and Selangor. At present, all recirculating tank systems have to be housed in enclosed buildings. These buildings are designed for temperate and cold climates with its main concern to ward off cold temperature from entering the building while maintaining the inside warm temperature. Buildings designed for temperate and cold climates are not suitable for tropical environments and are thermally uncomfortable (and may become too hot if kept enclosed) for Malaysians. The proposed study is undertaken: a. to measure the environmental conditions of selected buildings that house recirculating tank Systems b. to develop suitable designs for aquaculture buildings for tropical environments. No such study has been done for the hot humid tropical climate and very few studies have been conducted on the designs of the aquaculture buildings for the temperate and cold condition

Information sharing on effects of exposure to building materials in adaptation projects / Sabarinah Sh Ahmad ... [et al.]

Research findings confirm the existence of hazardous and toxic substances in most building materials. There is limited studies and information on building materials and the effects to health and safety. This study develops an evaluation method that is used to identify the presence of hazardous substances from building materials and assess their public health impact. The information allows stakeholders to identify potential risks and could improve knowledge sharing on building materials information on health and safety in the built environment industry

Multimodal biometrics based on identification and verification system

The need for an increase of reliability and security in a biometric system is motivated by the fact that there is no single technology that can realize multi-purpose scenarios. Experimental results showed that the recognition rate of Heart Sound Identification (HSI) model is 81.9%, while the rate for Speaker Identification (SI) model is 99.3% from 20 clients and 70 impostors. Heart Sound-Verification (HSV) provides an average Equal Error Rate (EER) of 13.8%, while the average EER for the Speaker Verification model (SV) is 2.1%. Electrocardiogram Identification (ECGI), on the other hand, provides an accuracy of 98.5% and ECG Verification (ECGV) EER of 4.5%. In order to reach a higher security level, an alternative multimodal and a fusion technique were implemented into the system. Through the performance analysis of the three biometric system and their combination using two multimodal biometric score level fusion, this paper found the optimal combination of those systems. The best performance of the work is based on simple-sum score fusion, with a piecewise-linear normalization technique which provides an EER of 0.7%

Fabrication of low-cost, cementless femoral stem 316L stainless steel using investment casting technique

Total hip arthroplasty is a flourishing orthopedic surgery, generating billions of dollars of revenue. The cost associated with the fabrication of implants has been increasing year by year, and this phenomenon has burdened the patient with extra charges. Consequently, this study will focus on designing an accurate implant via implementing the reverse engineering of three-dimentional morphological study based on a particular population. By using finite element analysis, this study will assist to predict the outcome and could become a useful tool for preclinical testing of newly designed implants. A prototype is then fabricated using 316L stainless steel by applying investment casting techniques that reduce manufacturing cost without jeopardizing implant quality. The finite element analysis showed that the maximum von Mises stress was 66.88MPa approximately with a safety factor of 2.39 against endosteal fracture, and micromotion was 4.3um, which promotes osseointegration. This method offers a fabrication process of comentless femoral stems with lower cost, subsequently helping patients, particularly those from nondeveloped countries

Window Width Estimation And The Application Of The Windowed Wigner-Ville Distribution In The Analysis Of Heart Sounds And Murmurs

This paper looks at the analysis of heart sounds and murmur using time-frequency signal analysis. The techniques used are the Wigner-Ville distribution (WVD) and windowed Wigner-Ville distribution (WWVD) that belonged to the bilinear class of time-frequency distribution. These techniques developed to provide high-resolution time-frequency representation for time-varying signals. Due the nonlinear operation involved, interference terms are introduced in the time-frequency representation. The signals of interest are modeled as multicomponent signals and the characteristics of the signal in time-lag plane are observed. From the time-lag plane, the interference components are identified, and the appropriate window width is selected in the WWVD to remove the interference. Analysis results show that WWVD produces more accurate time-frequency representation compared to the WVD and the signal-to-interference is used to quantify the improvemen

Analysis And Classification Of Heart Sounds And Murmurs Based On The Instantaneous Energy And Frequency Estimations

This paper proposes the use of the instantaneous energy and the frequency estimation in the classification of the heart sounds and murmurs for common heart diseases. It has been known that the present of the heart murmurs in one's heart sound indicates that there is a potential heart problem. Thus, the goal of this work is to develop a technique for detecting and classifying murmurs. Such a technique can be used as part of a heart diagnostic system. The analysis is performed based on a set of 102 data for various heart sounds. To discriminate the various heart sounds, the instantaneous energy and frequency estimation is used to estimate the features of heart sound. The techniques used to estimate the instantaneous frequency are the central finite difference frequency estimation (CFDFE) and zero crossing frequency estimation (ZCFE). From the instantaneous energy and frequency estimate, the energy and frequencies of the heart sounds are defined as the features of the heart sounds that can uniquely discriminate the various heart sound

Malay speaker recognition system based on discrete HMM

This paper presents the design and implementation of Malay speaker recognition system using discrete hidden Markov model (HMM) as the classifier. A series of speaker recognition experiments was performed using 99 speakers (13 clients and 86 imposters) recording database consisting of isolated digit utterances. For a seven digit long sequence, 0.96% EER was achieved

Women participation in business:a focus on franchising venture

The number of women involved in business sector is a growing phenomenon worldwide.Despite this scenario, the involvement of women in business particularly in franchising business is not being studied thoroughly and systematically. Franchising is known as a mean to provide opportunities to minorities and women who have interests to venture in business. This study attempts to look into a few questions related to women involvement in franchising venture. The questions are: 1) what is the pattern of womens participation in franchise business 2) problems faced by franchisees in the franchise business and 3) what are the role of government in promoting and assisting the women in their franchise business. The study is conducted by taking samples of 24 women franchisors and 31 franchisees all over Malaysia participating in franchise business. The findings show that there are less women franchisors in the top administrative positions such as the managing director, chairman and the general manager. The top three problems identified by franchisees are limited control in managing the franchise business, the power to terminate the agreement by franchisees and tough competition facing them as franchisees. The government is really showing their commitment and doing their part in supporting the franchise business by giving loans and setting up agencies which seriously looked into the matters of franchising in Malaysia