Work design improvement at Miroad Rubber Industries Sdn. Bhd.

Erul Food Industries known as Salaiport Industry is a family-owned company and was established on July 2017. Salaiport Industry apparently moved to a new place at Pedas, Negeri Sembilan. Previously, Salaiport Industry operated in-house located at Pagoh, Johor. This small company major business is producing frozen smoked beef, smoked quail, smoke catfish and smoked duck. The main frozen product is smoked beef. The frozen smoked meat produced by Salaiport Industry is depending on customer demands. Usually the company produce 40 kg to 60 kg a day and operated between for four days until five days. Therefore, the company produce approximately around 80 kg to 120 kg per week. The company usually take 2 days for 1 complete cycle for the production as the first day the company will only receive the meat from the supplier and freeze the meat for use of tomorrow

Code wars: steganography, signals intelligence, and terrorism

This paper describes and discusses the process of secret communication known as steganography. The argument advanced here is that terrorists are unlikely to be employing digital steganography to facilitate secret intra-group communication as has been claimed. This is because terrorist use of digital steganography is both technically and operationally implausible. The position adopted in this paper is that terrorists are likely to employ low-tech steganography such as semagrams and null ciphers instead

Adobe Acrobat image compression: An Investigation into the effects of compression in Acrobat 4.0 on image reproducibility for digital printing

The aim of this project is to investigate each [digitally printed file] compression setting in Acrobat 4.0 Distiller by using and comparing the effects of each on a digitally printed file. The goal is to define the visual results these compressions will yield according to the components of a given file

An Investigation into the distuibution of portable documents in a prepress environment

Portable document files (PDF\u27s) are used in many types of environments; such as, office, world wide web, and desktop publishing to name a few. PDF technology allows electronic documents to become truly portable. PDF files maintain their original look and feel across various computer systems and platforms. PDF use in a prepress environment was tested by creating various electronic mechanicals with numerous file formats and having these PDF files imaged across the country on various high resolution imagesetting devices. It has been determined that PDF files can be used in a prepress environment at this point in time in some situations

Paper-based Screen-printed Passive Electronic Components

This thesis investigates paper-based electronics in terms of various substrates, fabrication methods and example devices, including touch sensors and microwave resonators. The term ‘paper’ is very broad and covers a wide range of substrates. A decision matrix has been created to determine the optimum paper for an application, based on a range of properties. Thermal evaporation and screen printing are compared for their use as fabrication methods for paper-based electronics and a second decision matrix has been compiled. Based on these decision matrices, screen printing onto a thicker matt paper was determined to be optimal. The printing process was further optimised to achieve the best results from the in-house process. Using this well-developed screen-printing method, passive components (including inductors and interdigitated capacitive touch sensors) were fabricated and found to be comparable with state-of-the- art results reported in the literature. Measurements from the touch pads were compared to modelling, with little variation between the two, and were confirmed to work under a wide range of conditions, showing that they are compatible with any user. The microwave characteristics, up to 3GHz, of both the chosen substrate and silver-flake ink were investigated through production of screen-printed transmission lines. These characteristics were then used to create microwave resonators. The frequency range is important for applications as the industrial, scientific and medical radio band (ISM band) lies between 2.45 and 2.55 GHz which includes Wi-Fi and Bluetooth. Initially, stub resonators were considered to determine the cause of differences between theoretical and measured results. Then spiral defected ground structures were made, with multiple resonances, and sensitivity to touch and humidity demonstrated. As paper is hygroscopic, the effect of humidity on paper-based electronics is of key importance. This has been considered for all the devices fabricated in this work and it has been determined that the change in permittivity of the substrate, as a result of absorbed water within paper, is the most dominant factor

Frequency-Selective Surfaces for Microwave and Terahertz Spectra

FREQUENCYselective surfaces (FSSs) made of subwavelength periodic structures have been broadly applied in various electromagnetic applications. Their main function is to tailor the frequency response to incident waves, or to obtain electromagnetic (EM) properties that do not exist in homogeneous natural materials. When increasing the design complexity to enhance performance, however, the computation cost hikes dramatically in analysis and synthesis as additional design variables are introduced. In contrast to such complexity increase, this thesis aims at systematically developing effective and efficient design and optimization approaches for FSS-based structures adopting fundamental unit-cell patterns, such as rectangular patches, rings and grids. Additionally, impedance matching to free space is thoroughly investigated and adapted as a means towards performance improvement in both absorbers and filters. Hereby, multiple designs are demonstrated with realizations from the microwave to the terahertz (THz) frequency spectrum. In spite of their simplicity, the proposed designs outperform the state-of-the-art counterparts in the literature by fully exhausting the potentials of their spatial structures and material attributes. Specifically, Chapter 3 challenges a common belief that adding an impedance matching superstrate to an absorber will broaden its operation bandwidth at the cost of increased total thickness profile. This Chapter proves that it is possible to increase the bandwidth-to-thickness ratio. The concept is firstly demonstrated at the circuit level, and then verified by full-wave simulations. The optimization process can be illustrated with an admittance Smith chart. The distinctive performance of the proposed single- FSS-layer absorber is justified with a figure of merit (FoM) which comprehensively involves the relative bandwidth, the normalized thickness and the level of reflectivity. In Chapter 4, a semi-analytical approach for absorber design is developed by systematically combining analytical, empirical and numerical techniques. The optimization space can be simplified from millions of exhaustive search cases to merely a few hundreds of seed simulations, by exploiting insights into the linearity, scalability and independence regarding the major components of an absorber. For any specified level of absorption and operation bandwidth, the obtained semi-analytical algorithm enables fast synthesis of an absorber with a minimal thickness. Both absorbers proposed in the above chapters have been realized using patterned resistive layers and experimentally validated under oblique angles of incidence for transverse-electric (TE) and transversemagnetic (TM) modes. The design methods can be readily expanded for structures of multiple FSS layers. In the terahertz frequency range, common microfabrication technologies do not accommodate those resistive inks used for silk-printing lossy FSS patterns. As an alternative, a sub-skin-depth metal layer with nanoscale thickness is proposed in Chapter 5 to meet this requirement. The Drude model is adopted to simulate the ultra-thin metallic FSS, as it satisfactorily describes the frequency dependent properties of noble metals. The proposed absorber is robust to dimensional tolerance in fabrication and attains a stable absorption bandwidth under oblique impinging waves. In Chapter 6, a frequency reconfigurable terahertz bandpass filter is proposed and experimentally verified. It includes two identical double-layer FSSs separated by an air spacer which can be mechanically tuned. The filter allows a highly selective transmission sweeping across a wide spectrum. The underlying mechanism can be explained from two perspectives, namely through interpretation as Fabry-Perot resonant cavity and through consideration of the admittance Smith chart. The designed device is insensitive to fabrication tolerances and stable to oblique angle of incidence. The fabricated filter confirms a 40% tuning range and less than 1 dB insertion loss. This design is among the first few practical reconfigurable terahertz bandpass filters reported in the literature. Overall, the research outcomes suggest that developing complicated FSS patterns with a large number of degrees of freedom is unnecessary in many cases if the potential of fundamental geometries is fully exploited through rigorous algorithmic optimization methods. The design approaches illustrated in this thesis are generic to all FSS-based structures and can potentially be extended to multi-FSS layers and impedance surfaces, to satisfy performance requirements in specific applications.Thesis (Ph.D.) -- University of Adelaide, School of Electrical and Electronic Engineering, 202

Area-Construction Algorithms Using Tangent Circles

Computer aided geometric design employs mathematical and computational methods for describing geometric objects, such as curves, areas in two dimensions (2D) and surfaces, and solids in 3D. An area can be represented using its boundary curves, and a solid can be represented using its boundary surfaces with intersection curves among these boundary surfaces. In addition, other methods, such as the medial-axis transform, can also be used to represent an area. Although most researchers have presented algorithms that find the medial-axis transform from an area, a algorithm using the contrasting approach is proposed; i.e., it finds an area using a medial-axis transform. The medial-axis transform is constructed using discrete points on a curve and referred to as the skeleton of the area. Subsequently, using the aforementioned discrete points, medial-axis circles are generated and referred to as the muscles of the area. Finally, these medial-axis circles are blended and referred to as the blended boundary curves skin of the area; consequently, the boundary of the area generated is smooth

Printed document integrity verification using barcode

Printed documents are still relevant in our daily life and information in it must be protected from threats and attacks such as forgery, falsification or unauthorized modification. Such threats make the document lose its integrity and authenticity. There are several techniques that have been proposed and used to ensure authenticity and originality of printed documents. But some of the techniques are not suitable for public use due to its complexity, hard to obtain special materials to secure the document and expensive. This paper discuss several techniques for printed document security such as watermarking and barcode as well as the usability of two dimensional barcode in document authentication and data compression with the barcode. A conceptual solution that are simple and efficient to secure the integrity and document sender's authenticity is proposed that uses two dimensional barcode to carry integrity and authenticity information in the document. The information stored in the barcode contains digital signature that provides sender's authenticity and hash value that can ensure the integrity of the printed document