Mechanical and Manufacturing Engineering

Nowadays, many distribution networks deal with the distribution and storage of perishable products. However, distribution network design models are largely based on assumptions that do not consider time limitations for the storage of products within the network. This study develops a model for the design of a distribution network that considers the short lifetime of perishable products. The model simultaneously determines the network configuration and inventory control decisions of the network. Moreover, as the lifetime is strictly dependent on the storage conditions, the model develops a trade-off between enhancing storage conditions (higher inventory cost) to obtain a longer lifetime and selecting those storage conditions that lead to shorter lifetimes (less inventory cost). To solve the model, an efficient Lagrangian relaxation heuristic algorithm is developed. The model and algorithm are validated by sensitivity analysis on some key parameters. Results show that the algorithm fi...

Network design is by nature costly and optimization models play significant role in reducing the unnecessary cost components of a distribution network. This study proposes a genetic algorithm to solve a distribution network design model. The structure of the chromosome in the proposed algorithm is defined in a novel way that in addition to producing feasible solutions, it also reduces the computational complexity of the algorithm. Computational results are presented to show the algorithm performance.

Distribution network design is one of the important issues in supply chain management. Two important sub-problems of distribution network design are inventory and location decisions. Traditional approaches considered inventory and location decisions separately which might result in suboptimal solutions. This paper considers the design of a distribution network and simultaneously determines the inventory and location decisions. The problem is formulated as a non linear mixed integer mathematical model and a hybrid heuristic algorithm, based on simulated annealing is developed to solve the model. The proposed algorithm finds optimal or near optimal solution in a reasonable computational time.

Biodegradable polymers, such as poly(lactic acid) (PLA) have attracted a lot of attention in the scientific community recently due to a rapid growth of intensive interest in the global environment for alternatives to petroleum-based polymeric materials. Fatty nitrogen compounds (FNCs), fatty amides (FA), fatty hydroxamic acids (FHA), and carbonyl difatty amides (CDFA), which were synthesized from vegetable oils, were used as one of organic compounds to modify natural clay (sodium montmorillonite). The clay modification was carried out by stirring the clay particles in an aqueous solution of FA, FHA, and CDFA, by which the clay layer thickness increased from 1.23 to 2.61, 2.84 and 3.19 nm, respectively. The modified clay was then used in the preparation of the PLA/epoxidized soybean oil (ESO) blend nanocomposites. They were prepared by incorporating 2% of CDFA-MMT and 3% of both FA-MMT and FHA-MMT. The interaction of the modifier in the clay layer was characterized by X-ray diffraction (XRD), and Fourier transform infrared (FTIR). Elemental analysis was used to estimate the presence of FNCs in the clay. The nanocomposites were synthesized by solution casting of the modified clay and a PLA/ESO blend at the weight ratio of 80/20, which has the highest elongation at break. The XRD and transmission electron microscopy (TEM) results confirmed the production of nanocomposites. PLA/ESO modified clay nanocomposites show higher thermal stability and significant improvement of mechanical properties in comparison with those of the PLA/ESO blend. The novelty of this study is use of FNCs which reduces the dependence on petroleum-based surfactants.

The influences of the machine parameters on machined parts are not always precisely known and hence, it becomes difficult to recommend the optimum machinability data for machine process. This paper proposes a method for cutting parameters identification using Multi adaptive Network based Fuzzy Inference System (MANFIS). Three Adaptive Network based Fuzzy Inference System (ANFIS) models were used in the first step to identify the initial values for the cutting parameters (cutting speed, feed rate, and depth of cut) using surface roughness as a single input, in the next step these parameters were modified and verified using another set of ANFIS models. Then, workpiece surface temperature is used as input for another set of ANFIS models to amend the final values of the cutting parameters. In this way, multi-input-multi-output ANFIS structure presented, which can identify the cutting parameters accurately once the desired surface roughness and in-process measured surface temperature wer...

Developing countries' experience is a huge gap in the coverage of collection-system and domestic wastewater treatment. Wherever the wastewater treatment facilities are available, they are running below the design standards. This leads to the discharge of pollutants into the natural water bodies and creating a negative impact on the environment and human health as well. Odor nuisance has become a major environmental issue worldwide with increasing public demand for better control of odor emissions from the municipal wastewater treatment facilities. Odor get affects the population directly and there is a trend that more and more peoples are becoming less tolerable with more odor emissions. Bad smell is often an indicator of the public potential health risk. Performance assessment of Haya water treatment plant in Manuma Village has been done. The main objective of this study is to assess the performance of the treatment plant with respect to produce high quality of treated water an...

In the manufacturing industry, machining is the process which has been used widely within the industry for carrying out various operations. By putting the materials together, mechanical parts can be formed with the help of raw materials change and these mechanical parts used in the formation of heavy and small machineries for the personal used and for the industrial use as well. Most of the metals are being manufactured with the help of machining. In the process of turning, the cutting parameters gained the opportunity to increase productivity. However, there also exists a consequence regarding the quality and deterioration risk and the life of the tool which need to be controlled to achieve greater efficiencies. The selection of parameters is based on the materials used in workpiece, tools, and other stuff. Additionally, the size of the tool matters as well, therefore it should also be selected carefully by keeping in mind the need of the machine and capability of the users regardi...

Water tank is an important element in water distribution system. The project is studied the characteristics of water tanks and the main objective of it to identify the selection criteria for the water tank. Furthermore, Selection of water tank is a challenge for many individuals and companies. The study is gathers information from many sources such as literature reviews, companies, questionnaire and experts in order to reach to the main important characteristic of water tanks. The selection of water tank depends heavily on the applications. As a result, it found that the best type of storage tanks for sweet water used for human consumption are two types, one of which is polyvinyl chloride to store a quantity of less than five cubic meters and the other is stainless steel tank to store more than five cubic meters. The study found that the best reservoir for irrigation and sewage uses is the carbon steel tank. On the other hand, the study found that the stainless-steel tank is best su...

Due to the unprecedented COVID-19 incident, higher education institutions have faced different challenges in their teaching-learning activities. Particularly conducting assessments remotely during COVID-19 has posed extraordinary challenges for higher education institutions owing to lack of preparation superimposed with the inherent problems of remote assessment. In the current study, the challenges of remote assessment during COVID-19 incident in higher education institutions were investigated taking Middle East College as a case study. For the study, questionnaires were prepared and data from 50 faculties were collected and analyzed. The study focused on the challenges of remote assessment in general and academic dishonesty in particular. The main challenges identified in remote assessment were academic dishonesty, infrastructure, coverage of learning outcomes, and commitment of students to submit assessments. To minimize academic dishonesty, preparing different questions to each student was found to be the best approach. Online presentation was also found to be good option to control academic integrity violations. Combining various assessment methods, for instance report submission with online presentation, helps to minimize academic dishonesty since the examiner would have a chance to confirm whether the submitted work is the work of the student.

The influences of the machine parameters on machined parts are not always precisely known and hence, it becomes difficult to recommend the optimum machinability data for machine process. This paper proposes a method for cutting parameters identification using Multi adaptive Network based Fuzzy Inference System (MANFIS). Three Adaptive Network based Fuzzy Inference System (ANFIS) models were used in the first step to identify the initial values for the cutting parameters (cutting speed, feed rate, and depth of cut) using surface roughness as a single input, in the next step these parameters were modified and verified using another set of ANFIS models. Then, workpiece surface temperature is used as input for another set of ANFIS models to amend the final values of the cutting parameters. In this way, multi-input-multi-output ANFIS structure presented, which can identify the cutting parameters accurately once the desired surface roughness and in-process measured surface temperature wer...

The warehouse layout problem includes assigning several different product types to confident areas of warehouse so that the cost of material handling from docks of the warehouse can be minimized. The layout of a warehouse may need to be modified to accommodate new product lines or to add more flexibility to the warehouse operations. In order to guarantee the success of a project, a detailed planning process should be followed. Concerning above, Decision Support Systems (DSS) are developed to assist company’s personnel (e.g., engineers and decision makers) to modify the arrangement of warehouse layout. Lately, DSS have been affected by new information technologies in design, deployment and implementation. Developing Web-Enabled decision support systems is a comprehensive area under discussion that describes how to build data-driven Web-enabled decision support systems using web programming framework. Availability and easiness of interactions in such a DSS frame inspired us to focus on developing an online warehouse location problem to simply deciding about productions which are always traffic. So that user specifies the area of the warehouse in number of bays, places for docks around the warehouse, gives the frequency of their usage, along providing demands and required area for each product type. Then the problem will be solved quickly to find the proper location of each product type for minimum material handling cost and information would be deposited. We follow these processes through an example in web pages.

This article studied how radio-frequency identification (RFID) technology can contribute to the optimization of production processes considering its cost effectiveness. RFID allows the automatic identification of objects such as, work-in-process, products, and raw materials. Toward that end, a survey and case study of Malaysian manufacturing enterprises was conducted in which their usage experience and perception about RFID applications in manufacturing were explored. The study was conducted to capture information on the usage, benefits, cost effectiveness, barriers, and area of application of RFID system to the responding companies. The study finds out that RFID application in manufacturing operations is most suited to large enterprises especially automotive and electrical and electronics sectors, and the identified barriers against RFID usage in manufacturing is mainly compatibility issues of RFID system, and inadequate awareness of RFID usage and benefits to manufacturing industries.

The study presents an algorithm for conflict-free Automated Guided Vehicle (AGV) routing minimizing travel time and total job tardiness. The problem is represented using one sub-chromosome for dispatching represented with random keys and the remaining sub-chromosomes for routing represented with priority-based encoding. The algorithm used weight mapping crossover (WMX) and Insertion Mutation (IM) for priority-based representation and parameterized uniform crossover (PUX) for random-key based representation. Conflict is detected and avoided using the route occupation time of each segment. Numerical experiment was conducted on the developed algorithm.

This study presents an algorithm for automated guided vehicle system routing. Priority-based genetic algorithm was used for genetic representation. The objective is minimal path transverse time. Weight mapping crossover (WMX) and insertion mutation was used as genetic operators. Conflict detection and avoidance was incorporated into the system using node and arc occupation time mapping for detection and replacement of the individual with faultless individual from the population for avoidance. Numerical experimentation was conducted to test the effectiveness of the algorithm.

Di Indonesia lembaga pendidikan Islam (madrasah) merupakan lembaga pendidikan kedua setelah pesantren. Pada historisnya lembaga pendidikan Islam ini mengalami dinamika sekaligus polemik yang sangat panjang sejak pra kemerdekaan hingga era pasca reformasi saat ini. Problematika yang dihadapi lembaga pendidikan Islam khususnya madrasah dinilai sangat terkait dengan kebijakan yang belum sepenuhnya berpihak pada pola pengembangan madrasah yang cenderung eksklusif dibanding dengan system pendidikan umum sehingga berimplikasi pada out put yang dihasilkan belum menempati posisi yang setaraf dengan yang lainnya, pada hal pendidikan Islam madrasah di era globalisasi penting melakukan reposisi secara sistemik, empiris-paradigmatik. Strategi reposisi ini dapat dilakukan dengan melihat bentuk-bentuk kebijakan dan sistemnya sekaligus diarahkan pada pola pengembangan yang lebih kompetitif di era global, inklusif, dan substansif dalam peranannya.

The paper presents an algorithm for integrated scheduling, dispatching, and conflict-free routing of jobs and AGVs in FMS environment using a hybrid genetic algorithm. The algorithm generates an integrated schedule and detail routing paths while optimizing makespan, AGV travel time, and penalty cost due to jobs tardiness and delay as a result of conflict avoidance. The multi-objective fitness function use adaptive weight approach to assign weights to each objective for every generation based on objective improvement performance. Fuzzy expert system is used to control genetic operators using the overall population performance improvements of the last two previous generations. Computational experiments was conducted on the developed algorithm coded in Matlab to test the effectiveness of the algorithm. Integrated scheduling of jobs in FMS which are in synchrony with AGV dispatching, scheduling, and routing proved to ensure the feasibility and effectiveness of all the solutions of the integrated constituent elements.

The work centered on the assessment of supply chain management of Zuma Bricks Nigeria Limited. The study attempts to assess the organization’s present supply chain management practice and its impact. The need to have an edge over competitors and enhance customer’s satisfaction by reducing cost and improve quality service delivery was the key issues that necessitated this research. The study identified the product of the company. The data were collected from the staffs of the company. An interview was conducted with the production manager of the company and thirty-four (34) questionnaires were administered to all the company staff while twenty-five (25) filled questionnaires were returned. The data was analyzed using descriptive statistics and results presented in form of tables. The result revealed that the organization’s supply chain strategy can be characterized as a push-based supply chain strategy which is slow to react to market changes, therefore stock-outs or excess inventory...

This study presents an algorithm for automated guided vehicle system routing. Priority-based genetic algorithm was used for genetic representation. The objective is minimal path transverse time. Weight mapping crossover (WMX) and insertion mutation was used as genetic operators. Conflict detection and avoidance was incorporated into the system using node and arc occupation time mapping for detection and replacement of the individual with faultless individual from the population for avoidance. Numerical experimentation was conducted to test the effectiveness of the algorithm.