Inventory Control Using A Service Constraint on the Expected Duration of Stockouts

This paper addresses the selection of a reorder point under a management-specified, maximum expected duration of stockout during a replenishment lead time. The cases of normal and Poisson demand are considered. In both cases graphical aids are developed, allowing easy determination of the reorder point so as to achieve a desired service level. The entire probability distribution of the durations of stockouts is also developed in each case.     

Emerging Advancements in Polypyrrole MXene Hybrid Nanoarchitectonics for Capacitive Energy Storage Applications

Journal of Inorganic and Organometallic Polymers and Materials - Recent advancement in nanotechnology has brought about the discovery of various nanomaterials such as graphene (GN),...     

Network intrusion detection based on deep learning model optimized with rule-based hybrid feature selection

ABSTRACT

Network Intrusion Detection System (NIDS) is often used to classify network traffic in an attempt to protect computer systems from various network attacks. A major component for building an efficient intrusion detection system is the preprocessing of network traffic and identification of essential features which is essential for building robust classifier. In this study, a NIDS based on deep learning model optimized with rule-based hybrid feature selection is proposed. The architecture is divided into three phases namely: hybrid feature selection, rule evaluation and detection. Several search methods and attribute evaluators were combined for features selection to enhance experimentation and comparison. The results obtained showed that the number of selected features will not affect the detection accuracy of the feature selection algorithms, but directly proportional to the performance of the base classifier. Results from the performance comparison proved that the proposed method outperforms other related methods with reduction of false alarm rate, high accuracy rate, reduced training and testing time of 1.2%, 98.8%, 7.17s and 3.11s, respectively. Finally, the simulation experiments on standard evaluation metrics showed that the proposed method is suitable for attack classification in NIDS.     

Improving e-payment security using Elliptic Curve Cryptosystem

The use of e-commerce has been associated with a lot of skepticism and apprehension due to some crimes associated with e-commerce and specifically to payment systems. The secure socket layer (SSL) protocol is trusted in this regard to secure transactions for sensitive applications like e-commerce. Unfortunately, the use of SSL protocol causes slow response time on the server which is a major cause of frustration for on-line shoppers. In this paper, we propose a secured credit-debit card payment systems based on Elliptic Curve Cryptosystem (ECC). We first examined ECC algorithm over prime fields GF(p), implement our proposed method using a typical transaction involving credit/debit card numbers and compared the performance with RSA cryptosystem. Our result shows that ECC is faster in terms of response to transaction request and occupies less memory space than equivalent RSA system. Thus, these makes it more suitable public Key cryptography scheme for application in a constraint open environment like payment system where fast operations are needed.     

Molecular and phenotypic characterization of Staphylococcus aureus strains isolated from carcass swabs and carcass drips of chickens slaughtered in the informal market in Gauteng Province,South Africa

The study was conducted to characterize Staphylococcus aureus strains from swabs and drips of dressed chicken carcasses sold at outlets in six townships in the informal market in Gauteng province, South Africa, using molecular and phenotypic methods. Seven genes (6 toxins and 1 antimicrobial resistance) comprising staphylococcal enterotoxin A (SEA), B (SEB), C (SEC), D (SED), exfoliative toxin A, toxic shock syndrome toxin, and MecA encoding methicillin resistance were assayed using polymerase chain reaction. The resistance of the S. aureus strains to 18 antimicrobial agents was determined using the disk diffusion method. The frequency of detection of the six toxin genes was sea (52.2%), followed by seb (10.9%), sec (6.5%), sed (2.2%), eta (93.5%), and tst (19.6%). The mecA gene was detected in 4.3% of the isolates. The predominant profiles of toxin genes detected were sea-eta (37.0%). All 63 isolates of S. aureus were resistant to one or more antimicrobial agents. The frequency of resistance was high to spectinomycin (98.4%), nalidixic acid (85.7%), and penicillin (84.1%), but low to gentamycin (1.6%) and cefotaxime (1.6%). The high frequency of toxin genes and antimicrobial resistance gene observed in S. aureus isolates from chicken could pose a challenge to food safety and may have therapeutic and zoonotic implications.     

Investigating the mechanical properties of sisal/coconut palm hybrid fiber reinforced epoxy composite

In this study, a facile hybridization of sisal/coconut palm reinforced epoxy composite, is presented. The fabrication method involved the use of hand lay-up techniques. The results of the fabricated composites were investigated by using the universal testing machine, hardness testing machine, scanning electron microscope, and an impact testing machine. In order to obtain optimize results for the tensile, flexural, and impact strengths of the fabricated samples, the fabrication procedures involved varying the volume fractions of sisal and coconut palm hybrid with different compositions. The maximum tensile, flexural, and impact strengths measured for the fabricated fiber/polymer composite, are: 45 MPa, 90 MPa, and 38.9 kJ/m². The scanning electron microscopy (SEM) and energy dispersive x-ray spectrometry (EDS) of the composites showed that the composites with equal volume fractions of sisal and coconut palm fiber exhibited better performance and better mechanical properties. Furthermore, the improved mechanical properties such as hardness, tensile strength, flexural strength and impact strength were obtained with fibers of longer length. By considering the excellent mechanical properties of the fabricated composite, it is envisaged that the composite be suitable for the manufacturing of helmet, automobile and train coach interiors.