Quality measurements of an UWB reduced-size CPW-fed aperture antenna

The paper presents a characterization of a compact co-planar waveguide (CPW)-fed slot loaded low return loss planar printed antenna designed for wireless communication and ultra-wideband (UWB) applications. Following a review of the antenna design, which was implemented and simulated using Agilent's Advanced Design System (ADS), the paper presents laboratory measurements of relative gain and impulse response transformed from the frequency domain. An antenna quality metric based on time-domain S21 is discussed and related to antenna quality metrics such as the System Fidelity Factor (SFF)

Multi-Channel Preemptive Priority Model for Spectrum Mobility in Cognitive Radio Networks

Cognitive Radio techniques have been proposed for improving utilization of the spectrum by exploiting the unoccupied bands of the licensed spectrum. This paper proposes a preemptive multi-channel access model for prioritized cognitive radio networks using an iterative method of queuing theory to solve the spectrum scarcity problem. The proposed model formulates accurate closed form of an expected waiting time in the queue, an expected number of users in the queue, an expected waiting time in the system, and an expected number of users in the system. The results compared to the basic model (without preemptive priority) show that, the waiting time in queue and the waiting time in the system compared to the basic model will be improved by 92.99% and 33.15% respectively for class one secondary user. The results also show that, the waiting time in queue and the waiting time in the system will be improved by 43.25% and 15.42% respectively for class two secondary users. The proposed model investigates the desirable schedules of primary and secondary users

Space-Time Structure and Electromagnetism

Two Lagrangian functions are used to construct geometric field theories. One of these Lagrangians depends on the curvature of space, while the other depends on curvature and torsion. It is shown that the theory constructed from the first Lagrangian gives rise to pure gravity, while the theory constructed using the second Lagrangian gives rise to both gravity and electromagnetism. The two theories are constructed in a version of absolute parallelism geometry in which both curvature and torsion are, simultaneously, non-vanishing. One single geometric object, {\it W-tensor}, reflecting the properties of curvature and torsion, is defined in this version and is used to construct the second theory. The main conclusion is that a necessary condition for geometric representation of electromagnetism is the presence of a non-vanishing torsion in the geometry used.Comment: 17 pages, LaTeX file, revised versio

Business Model Canvas Perusahaan Pengolah Rumput Laut

Winner Perkasa Indonesia Unggul is a SME that sells product based on seaweed processing. The enterprise is trying to improve their business activity on seaweed processing products. The purposes of this research are to identify the existing business model at the enterprise, to evaluate the model, and to generate a new business model prototype with the Business Model Canvas method analysis. This research is a case study on a company, and conducted in March-May 2016. The data used are primary data in the form of interviews and internal company data, while qualitative analysis used to evaluate the business model, and the SWOT analysis method used to help generating new business model prototype. The results of this research were two alternative of business model prototype for the enterprise's development in the future. The first alternative is trying to classify new customer segment, and followed by creating the new value proposition. With the additional of new customer segment and the new value proposition, it caused the enterprise to extend the channels by optimalizing technologies, and eventually increase the revenue stream of the enterprise. The second alternative is trying to increase the customer relationship by creating the new value proposition. It will raise the opportunity to make an alliance or partnership for helping the business activity of the enterprise. However, the changes on some parts of the business model will affect the enterprise's cost structure