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Estimating change point in multivariate processes via simultaneous mean vector and covariance matrix
Full text linkIn many industrial processes, several quality characteristics are inevitably related. In this situation, the mean vector and covariance matrix must be simultaneously monitored and controlled to determine whether a multivariate process is in control. With the increase in the number of variables, the performance of control charts is significantly reduced, and the time delay between the actual time of change in the process and the warning time of the control chart increases, which is one of the main challenges when using multivariable control charts. Between the real-time and the change time (called the change-point - CP), especially during the simultaneous monitoring and controlling of the parameters, the mean vector, and the covariance matrix cause problems such as delay or stoppage of the production lines or services, as well as inconsistent production of products or services. To improve this, a new way of estimating the CP will help statistical process control (SPC) professionals identify the cause(s) of out-of-control (OC) conditions, thus providing better feedback for process improvement. This study presented a new method based on an artificial neural network (ANN), which first examined the OC conditions for a multivariate process using the multivariate exponentially weighted moving average (MEWMA) and multivariate exponentially weighted mean square (MEWMS) control charts. Then, the ANN-fitting method was used to diagnose the cause(s) of OC conditions using the machine learning (ML)-classifier and estimating the length of delay time. Finally, the change point (CP) was estimated by integrating all these methods. The performance of the new approach was validated by comparing it with the results from another study. It also validated the proposed method developed by evaluating the accuracy and precision of this research. As a conclusion, the MEWMS chart was the best for detecting the OC condition while the support vector machines (SVM) gaussian model best to diagnoses the cause(s) o f the OC condition. The model provided has estimated the change point on one sample with difference over 10,000 tested cases (simulated) with a probability of 99%, which is an accurate and reliable model for a practical approach
An improved cuckoo search algorithm using elite opposition-based learning and golden sine operator
No full textAn improved cuckoo search algorithm using elite opposition-based learning and golden sine operator
Peng ChengLi, Xuan YuZhang, AzlanMohd. Zain & Kai QingZhou
The existing cuckoo search (CS) algorithm has the drawbacks of slow convergence speed, low convergence accuracy, and easy to fall into local optimum. An improved cuckoo search algorithm is proposed in this manuscript to overcome the mentioned shortages using elite opposition-based learning and golden sine operator (EOBL-GS-CS). The modifications could be summarized from two aspects. On the one hand, the elite opposition-based learning (EOBL) mechanism is employed to improve the diversity and quality of the population, preventing the algorithm from falling into the local optimum. On the other hand, the golden sine operator accelerates the algorithm’s convergence speed and improves the algorithm's optimization ability. In the verification part, 14 unimodal and multimodal benchmark functions are used to highlight the characteristics of the proposed algorithm. The experimental results show that, compared with the standard CS and other variants, the EOBL-GS-CS has a faster convergence speed, higher solution accuracy, and significantly improved optimization performance
Impedance-based haptenation of skin sensitizers with self-assembled monolayer of gold nanoparticles and cysteine modified screen printed carbon electrode
No full textHaptenation of skin sensitizer is indicated because of the covalent attachment of a skin sensitizer to a skin protein. The idea of this research is to explore the haptenation of skin sensitizer with a modified screen printed carbon electrode (SPCE) and a self–assembled monolayer of gold nanoparticles (AuNPs) and cysteine (designated as ACC modified SPCE) using the impedance technique. The ACC modified SPCE was characterized using Fourier–Transform infrared spectroscopy–attenuated total reflectance (FTIR–ATR), atomic force microscopy (AFM), and Energy Dispersive X–Ray Spectroscopy (EDX). The presence of AuNPs and cysteine on the working electrode of the ACC modified electrode was detected by FTIR–ATR and EDX. AuNPs, possessing a homogeneous dot shape, and cysteine was randomly distributed on the carbon surface of SPCE shown by FESEM images. The AFM images indicated the possibility of a monolayer of adsorption of skin sensitizer onto ACC modified SPCE. The ACC modified SPCE has good reproducibility and stability with an RSD of 8.43 %. In addition, the interaction of extreme/strong skin sensitizer with the ACC modified SPCE was discovered with a high value of changes of charge transfer resistance of skin sensitizer (ΔRCTskinsensitizer) when compared to moderate and weak/non skin sensitizers. A total of 9 min was reported to be the optimum contact time of the skin sensitizer onto ACC modified SPCE. The adsorption isotherm studies of skin sensitizers with ACC modified SPCE showed Langmuir isotherm adsorption and spontaneous mechanism. Maleic anhydride (as a model of extreme/strong skin sensitizers) showed a fast–binding rate (18.2149 M−1) with the addition of a slow dissociation rate of 0.0549 M, while glycerol (as a model of weak/non skin sensitizer) showed a slow binding rate of 4.5977 M−1 as a result of a rapid dissociation rate of 0.2175 M. The change in Gibbs free energy (ΔG°) was calculated for ACC modified SPCE with glycerol and maleic anhydride to be at –3.78 × 10+03 kJ/mol and –7.19 × 10+03 kJ/mol, respectively. This study proved that the ACC modified SPCE could be used for routine screening during the early product development stage in qualitative skin sensitization measurements
The relationship of trust in authority, procedural fairness and tax policy reform on voluntary compliance during the covid-19 pandemic in Malaysia
No full textThe COVID-19 pandemic which occurred in early 2020 is the most concerning topic around the world. Without a doubt, Covid-19 has badly given implications for social, economic, and political aspects of most nations which also impacted global human lives. In Malaysia, it is proven that Covid-19 has mainly caused business activities due to the travel restrictions and border closures such as Movement Control Order (MCO) which is also implemented around the globe. This significant impact on the economy eventually included the tax sector. Tax as the main source of government revenue is crucial to fund crisis response and recovery, in addition to balancing the government’s effort in rebuilding Malaysia’s fiscal resilience while maintaining its social responsibilities. The condition of taxpayers during this pandemic period also affects the fulfillment of their tax obligation and will give an impact on the country's revenue. This article is an early study to examine the effect of trust in authority, procedural fairness, and tax policy reform on the voluntary compliance response to Covid-19 in Malaysia. Understanding the level of trust in authority, procedural fairness, and tax policy reform is essential to improve tax voluntary compliance. Hence, helps to understand that voluntary compliance facilitates enhancing a viable source of funding for the government
Implementation of industrial automation water distribution system utilizing PLC: a laboratory setup
No full textIn this paper, an automated process control utilizing programmable logic controller (PLC) is implemented to a laboratory setup of a water distribution system. A common implementation of water transference in the local water utility company in a water distribution network is controlled manually, the process of distributing clean water to customer to meet the customers’ demand is not efficient, thus difficult to achieve. Therefore, in this paper, an automated water distribution system is proposed by controlling the water level of the reservoir tank, representing demand from customers. The automation process is achieved through the utilization of OMRON CP1H PLC, the central processing unit of the system. The water level is measured by water-level sensors and monitored by flow rate meter for high accuracy measurement. The speed of the water pumps is regulated by the variable speed drive (VSD) based on several set-points of the water level of the reservoir tank for low, medium, and high level. The automated system is then monitored and controlled through a SCADA system using OMRON CX-Supervisor. From the results obtained, it can be observed that the proposed system able to control the water level automatically, continuously thus improving the efficiency of the water distribution system
A systematic review for supply chain integration and risks
No full textIn past decades, supply chain integration is used as a tool for manufacturers to earn competitiveness and improve performance. With the pace of globalization, the scope of the supply chain network has extended and increased the challenges for supply chain integration. This means the integrating processes have enhanced the vulnerability of a supply chain network. Recently, the integrated global supply chains are disrupted by disease outbreaks, natural disasters, and canal blocks. The risks embedded in the supply chain are catching the eyes of academicians and practitioners. Changes are expected after global supply chain disruptions concerning the size of the network, supplier locations, and network management, which are highly related to supply chain integration and supply chain risk management. Hence, this paper aims to investigate the dimensions of supply chain integration adapting to the changing world. Furthermore, this study adopts the systematic review approach to identify the dimensions of supply chain integration and construct a supply chain integration framework. The review found that supply chain integration dimensions including internal integration, supplier integration, customer integration, and service provider integration are important for practitioners. Ultimately, this review recommends future studies to focus on the impact of supply chain integration on supply chain risk management
Food safety legal issues in home-based food business
No full textFood safety in home-based food business play an important role in preventing foodborne disease in the community. However, poor hygiene standards of preparation, process and food serving among the home-based food business is endangering the health of consumers. The aims of this study are to are to examine the food safety issues in the home-based food business in the legal perspective and secondly is to propose amendment to food safety legislations for home-based food business in Malaysia. This research will employ qualitative analysis by way of semi-structured interviews with officers from the Food Safety and Quality Division Ministry of Health Malaysia and home-based food business owners to obtain their perspectives on the food safety legislations. It is found that issues surrounding food safety regulations on home-based food business in Malaysia are firstly on the absence of the regulations include the category of home-kitchen as one of which has resulted home-based food business operators to be excluded from the food safety standard of procedure. Secondly, home-based food business owners are reluctant to register their business on the ground to save cost in business. It is suggested to include the category of home-based food business in the regulations and to organise awareness campaign for business owners to spread awareness on importance of business registration and food safety practice in their business. Keywords: Home-based Food Business, Food Safety, Food, Disease, Food Handlers
An introspective review on commutation failure inhibition strategies in LCC-HVDC transmission networks
No full textLine-Commutated Converter High Voltage Direct Current (LCC-HVDC) technology plays an irreplaceable role in power transmission systems due to its thyristor's superior power handling capability and low operating power losses. Nevertheless, one of the main challenges associated with such systems is the high risk of commutation failure caused by inverter AC faults which leads to temporary cessation in transmitted power and severe stress on the converter equipment. The purpose of this study is to provide a comprehensive overview of the available strategies for commutation failure mitigation in LCC-HVDC networks, and then to investigate their mechanism, effectiveness, and limitations. In addition to describing the existing solutions presented to date, and classifying them into specific groups, a comparative analysis has been carried out in which the main merits and demerits of each category are presented. Finally, based on the analyzed technical literature, some insights and future research directions are pointed out
Ownership issues of old-stratified scheme: Failure factors of strata title application
No full textA special building is representing the old-stratified scheme occupied before June 1996 or from June 1996 to 11 April 2007 as stated in Strata Titles Act 1985. It is highlighted for the absence of strata title that is resulted from the failure of strata title application. However, even strata title legislation relating to strata title application are improving, the number of strata title applications for special building are still showing deficiencies. Hence, this paper attempts to explain the factors that contribute to the failure of strata title applications for special buildings in Malaysia
Challenges in managing university land use to generate income: A review
No full textPublic universities have recently struggled to maintain operating costs due to a budget reduction from Federal Government. Thus, universities must diversify their revenue streams by utilizing the land as one of their valuable assets. However, since the university is not a for-profit institution, it is difficult for them to generate income from land use. This study examines the challenges that universities encounter when managing the usage of their land for the purpose of generating income. The challenges are determined using content analysis of secondary data and the result of this study has identified the four main challenges