فهرست مطالب

  • Volume:6 Issue: 3, 2019
  • تاریخ انتشار: 1398/06/10
  • تعداد عناوین: 7
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  • S. M. Tazim Ahmed *, Chitra Lekha Karmaker, Md. Emon Ahmed Pages 161-176

    The Ready-Made Garment (RMG) sector, the highest earning foreign currency segment, has had a great influence on GDP (gross domestic product) since 1980. With new technology adaption as well as cheap labor force, this sector has placed the second position of exporting after China. To capture the market position, the management has to give more attention on maintaining Safety, Health, and Environment (SHE) guideline properly. This paper proposes a structured framework for occupational risk assessment by means of quantitative way and also provided remedies of those risks in garments industry in the context of Bangladesh. Here, the Analytic Hierarchy Process (AHP) method is applied for measuring the severity of safety, healthy, and environmental risk factors and QFD to prioritize the possible solutions. Through the literature review and extracting opinions from experts, a total of four evaluation criteria and sixteen risk factors under SHE categories are recognized and examined via AHP approach to measure their importance. The results demonstrate that ‘Fire’ ‘Contagious diseases’, and ‘Noise’ take high priority in safety, health, and environment related risk factors. The findings of this paper may help the garment industry effectively through the proper identification of the most influential risk factors and generating solutions to mitigate this issue.

    Keywords: Occupational risks, OSHA guidelines, AHP, QFD, garments industry, Sustainability
  • Hamiden Khalifa * Pages 177-183

    Investment problem is one of the most important and interesting optimization problems. This problem becomes more difficult when we deal with it in an uncertain and vague environment with chaos data. This paper attempts to study the investment problem with uncertain return data. These data are represented as chaos numbers. Dynamic programming is applied to obtain the optimal policy and the corresponding best return. Finally, a numerical example is given to illustrate the utility, effectiveness, and applicability of the approach to the problem.

    Keywords: Investment problem, Chaos numbers, Dynamic programming, Optimal Policy, Best return
  • Filscha Nurprihatin *, Meilily Angely, Hendy Tannady Pages 184-199

    In the manufacturing process, the machine is very important because downtime can inhibit and even stop production. We focused on the highest downtime that occurred in a particular product line and critical machine. This research contributes to overcoming and making the machine's performance and ability better. We make use the Total Productive Maintenance (TPM), which started by calculating Overall Equipment Effectiveness (OEE) and Six Big Losses. This study also provides the maintenance attempt to increase the effectiveness and to eliminate losses incurred by calculating Mean Time Between Failure (MTBF) and Mean Time To Repair (MTTR). Finally, we proposed the TPM implementation to improve the effectiveness of the machine. The result showed that the OEE has not reached the ideal value due to the low availability. Breakdown losses contributed to the biggest factor in the loss. The way to overcome the cause of breakdown losses is to increase performance maintenance, by calculating and evaluating MTBF and MTTR. This research presented the cause of the low value of OEE, provided the performance maintenance policy according to MTBF and MTTR, and proposed the TPM implementation.

    Keywords: Total Productive Maintenance, Overall Equipment Effectiveness, Six Big Losses, Mean Time Between Failure, Mean Time To Repair
  • Mohammad Hemati * Pages 200-218

    The prediction of economic variables is one of the main issues in a country's macro decisions. Since in many cases there is no historical data for this purpose and it is necessary to have more than one output, it is necessary to use expert opinions and consequently, model expert opinions in the form of mathematical functions, adds to the complexity of the task and the importance of the problem. To solve such problems, this paper presents a ten-step process using fuzzy rule-based systems. At the first step, the three inputs that include: the price of OPEC oil, the level of Iran and Saudi relations and the level of political tension in OPEC member countries and also the three output variables that include: the amount of employment, the economic growth, and the oil price forecast, have been modeled in the form of trapezoidal and triangular functions. Then, these variables have been converted to linear functions. In the next steps, the three-dimensional decision tables were designed and then by using the fuzzy rule-based systems (if, ... Then...), the preconditions and sequences (results) of the decision rules were written and coded in the Matlab software. The results indicate that the outputs are in line with the existing economic realities of Iran and that three input variables to a certain extent can cause changes in the three output variables. Less technical so far with problems with this complexity of problems are capable of results with this obvious.

    Keywords: Fuzzy Rule-Based Systems, Fuzzy logic, Crude Oil, Predicting, Macroeconomic Variables in Iran
  • Ganjar Gandara *, Riko Muri, Humiras Hardi Pages 219-231

    The purpose of this research is to make the right design in improving the service of selling formaldehyde products in the Chemical Industry according to customer requirements by implementing Quality Function Deployment. Complying on customer satisfaction is important in the competitive global market, which can be realized by innovation and quality fulfillment. Innovation and quality are not only about fulfilling product specifications, but also whether the product is marketable. Furthermore, as the show of average sales formaldehyde product in the last 3 years is 71.6% of a target whereas the formaldehyde market share is very large. It is important to develop sales services of products to meet customer needs. Quality Function Deployment (QFD) is a tool that can translate the customer needs to obtain a technical response in complying with the customer’s satisfaction. Method of this research uses customer satisfaction survey form, the data was collected through a field survey with questionnaires. The market survey generates 9 critical points of the services in selling products. House of quality (HOQ) was developed and analyzed to describe the relationship between customer expectations and technical responses. The overall analysis suggests three priorities of technical responses of a design concept to take into account in the service development. Priority as an action plan is additional hunting line for customer - Marketing and Sales (23%), provide schedule regular meeting with customer - include related department (15%), and shipment schedule to increase On-Time Delivery (OTD) from 80% to 95% through collaborating with external transportation company (14%). Finally, Quality Function Deployment (QFD) is implementing for increasing sales formaldehyde products through customer satisfaction.

    Keywords: Quality Function Deployment, Formaldehyde, Customer Satisfaction
  • Aahmad Makui *, Farzaneh Ashouri, Farnaz Barzinpour Pages 232-250

    In this paper, we introduce a two stages model for allocation of injuries and medical supplies to medical centers. In the first stage a multi objective mathematical model allocates injured people from the affected neighborhood to medical centers. In the second stage a single objective linear model allocates medical supplies from the supply points to medical centers. The first stage’s objective is simultaneously minimizing the total relief time and costs and maximizing the level of matching the type of injury with the specialized field of the medical centers those injuries are sent. The second stage’s objective is to minimize the costs of allocating medical supplies to medical centers. An integrated model that combines the two previous models is presented and comparing the results with the two stages model. Proposed models are applied to one of the districts of Tehran to demonstrate their effectiveness. The case study includes two affected neighborhood and four medical centers and three supply points. ϵ-constraint method is used to produce the Pareto optimal solutions in a MOMP.

    Keywords: Emergency condition, Mathematical Modeling, assignment, Multi-objective Programming, ϵ-constraint method
  • Sadam Hussain Khan * Pages 251-267

    Clays have a tendency to undergo volumetric changes when they interact with water. These soils are a very common reason for most of the foundation failures due to their degraded properties. With the growing need of infrastructure development, avoiding these soils for future constructions may not be possible. The present research is intended to examine the effect of gypsum and bagasse ash on the properties of clays and evaluate their potential for the stabilization and improvement of engineering properties of these soils. Gypsum is naturally occurring mineral and bagasse ash is a waste product produced by sugar-mills. Two types of swelling clays i.e. Low plastic, and high plastic clay, are used in this research for stabilization. Atterberg’s limits, compaction characteristics, unconfined compressive strength, California Bearing Ratio and swell potential of these soils are determined in both untreated as well as in treated form with varying content of gypsum and bagasse ash. The improvement observed for the combination of gypsum and bagasse ash is more significant as compared to the individual effect of gypsum or bagasse ash. Results obtained indicate that gypsum and bagasse ash can provide an effective and economical method for the improvement of Low and high plastic clays.

    Keywords: clays, Cation exchange, Chemical Admixtures, Gypsum, Pozzolans, bagasse ash, Expansive Soils