Multidimensional random sampling for Fourier transform estimation

This research considers the Fourier transform calculations of multidimensional signals. The calculations are based on random sampling, where the sampling points are nonuniformly distributed according to strategically selected probability functions, to provide new opportunities that are unavailable in the uniform sampling environment. The latter imposes the sampling density of at least the Nyquist density. Otherwise, alias frequencies occur in the processed bandwidth which can lead to irresolvable processing problems. Random sampling can mitigate Nyquist limit that classical uniform-sampling-based approaches endure, for the purpose of performing direct (with no prefiltering or downconverting) Fourier analysis of (high-frequency) signals with unknown spectrum support using low sampling density. Lowering the sampling density while achieving the same signal processing objective could be an efficient, if not essential, way of exploiting the system resources in terms of power, hardware complexity and the acquisition-processing time. In this research we investigate and devise novel random sampling estimation schemes for multidimensional Fourier transform. The main focus of the investigation and development is on the aspect of the quality of estimated Fourier transform in terms of the sampling density. The former aspect is crucial as it serves towards the heart objective of random sampling of lowering the sampling density. This research was motivated by the applicability of the random-sampling-based approaches in determining the Fourier transform in multidimensional Nuclear Magnetic Resonance (NMR) spectroscopy to resolve the critical issue of its long experimental time

Determination of effective diffusion coefficient of immobilized Baker's yeast invertase in various concentration of PVA-alginate matrix

Baker's yeast invertase is immobilized in PVA-alginate matrix using an improved method. PVA beads were prepared by adding calcium alginate to improve its stability, mechanical and chemical properties. Boric acid was used as the cross-linking agent and additional chemicals consisting of 10% boric acid and sodium sulphate solution was used as a treatment solution to harden the PVA-alginate beads. The determination of the effective diffusion of PVA-alginate matrix the vital step in optimizing the preparation of immobilized and water-soluble biocatalyst. In this study the two-level full factorial design was used to investigate the effect of PVA and boric acid concentrations and diffusions coefficient. Diffusion coefficient (De) is one of the factors that significantly affect the mass transport within the immobilization matrix. De value varies for each concentration of PVA and boric acid. The result concluded that both factors significantly affect the De. A maximum De value of 5.0141 x 10(-5) cm2s-1 was obtained at boric acid and PVA concentraion of 7w/v and 10.5 w/v respectively

THE IMPLEMENTATION OF PORTFOLIO-BASED TEACHING MODEL TO IMPROVE STUDENT’S ACTIVITIES OF ACCOUNTING EDUCATION STUDY PROGRAM IN THE TEACHING AND LEARNING PROCESS OF AUDITING

This research aims at exploring students’ activities during the teaching and learning process of auditing which employs portfolio-based teaching models. The design of this research is action research. The subject of the research was 101 students’ of accounting education study program who take auditing courses in the academic year of 2008/2009. The data were collected through observation and documentation. At the end, the conclusion was taken to improve the activities. The research findings show that the student’s learning activities during the teaching and learning of auditing improve indicated by the 10% improvement of the activities in identifying the cases. Besides, the activities of cases selection for classroom study improve up to 5%. The activities of collecting the study cases improve up to 10%. The activities of presenting the portfolio improve up to 10%, the activities of presenting the data improve up to 10%. The score of student’s portfolio tasks ranging between 86-90 increases up to 31,58%, the score ranging between 81-85 increases up to 3,76%, and the score ranging between76-80 decreases up to 35,35%

Distributed allocation of mobile sensing swarms in gyre flows

We address the synthesis of distributed control policies to enable a swarm of homogeneous mobile sensors to maintain a desired spatial distribution in a geophysical flow environment, or workspace. In this article, we assume the mobile sensors (or robots) have a "map" of the environment denoting the locations of the Lagrangian coherent structures or LCS boundaries. Based on this information, we design agent-level hybrid control policies that leverage the surrounding fluid dynamics and inherent environmental noise to enable the team to maintain a desired distribution in the workspace. We establish the stability properties of the ensemble dynamics of the distributed control policies. Since realistic quasi-geostrophic ocean models predict double-gyre flow solutions, we use a wind-driven multi-gyre flow model to verify the feasibility of the proposed distributed control strategy and compare the proposed control strategy with a baseline deterministic allocation strategy. Lastly, we validate the control strategy using actual flow data obtained by our coherent structure experimental testbed.Comment: 10 pages, 14 Figures, added reference

The importance of design characteristics in walking from student's perspective: a case study in Universiti Kebangsaan Malaysia

Walking is a common form of physical activity, which has a lot of both social and recreational impacts. It is studied as a way of achieving sustainability. Many researchers recommend that walking can increase mental and physical health. Spectators of new urbanism recommend that the good design will encourage walking. There are several characteristics for designing walkable communities, which were frequently described in researches by many authors. In this paper, the four criteria noticed for making walkable university campus include connectivity, accessibility, safety/security and comfort. These criteria have been assessed by gathering survey in the Universiti Kebangsaan Malaysia to find out if these criteria can cause or affect walkability in university campus and it has been supported by previous studies. The result of the survey shows that these criteria are important from students’ perspective as high numbers of the students consider these characters as important for walking activity. The conclusion is to achieve walkable university campus as it will be necessary to evaluate present walking conditions, research walking behavior in different settings and consider these four criteria in designing campus for improving walking condition

Response surface methodology approach to study the influence of PEG and water in cellulose acetate dialysis membranes

Flat sheet asymmetric dialysis membranes were fabricated using phase inversion method from polymer solution consisting of cellulose acetate, acetic acid, polyethylene glycol (PEG) and distilled water. The effect of acetic acid/PEG ratio and the distilled water content in the dialysis membrane were being investigated with respect to the urea clearance performance. Response surface methodology (RSM) was used to design the experiments and analysed the results obtained. The analysis revealed that the significant factor that affects the cellulose acetate dialysis membrane performance in terms of urea clearance is the ratio of acetic acid/PEG. Dialysis membrane with higher ratio of acetic acid/PEG gives higher urea clearance percentage due to the formation of finger like macrovoids. The relation between the urea clearance and the ratio of acetic acid/PEG in the given range of 4 – 14, was a quadratic model and the mathematical model suggested could adequately describe the performance indicators within the limits mentioned

RESTful web services for an ERP system for social services

Abstract. The advances in hardware and software have been rapidly integrated by organizations, especially in the healthcare sector, demanding new approaches for software to provide more reliable products, under well-known quality standards. This thesis investigates, designs and implements a set of operationally crucial RESTful web services for Invian Oy ERP system, DomaCare. Today, DomaCare is one of the fastest growing and developing software solutions in Finland in the healthcare sector. Thousands of satisfied healthcare professionals across Finland use DomaCare daily. DomaCare is a versatile ERP system designed specifically for the social sectors. This thesis describes the theoretical part of software architecture and software architectural style, which support understanding REST. Second, the thesis introduces the environment and tools required for the development stage. Third, the thesis presents the action and sequence diagrams for each use case to support the overall understanding of the system in a higher level of abstraction. Moreover, unit tests were implemented in this thesis for each use case, and, finally, the approach which was employed to validate the system is presented. In conclusion, the thesis concludes that based on the literature review, implementation, the results obtained from the unit tests, and the system validation fulfilled the goals set for this thesis.Tiivistelmä. Laitteistojen ja ohjelmistojen tekniikkaa on nopeasti integroitu organisaatioihin erityisesti terveydenhoitoalalla. Tämä vaatii ohjelmistojen osalta uudenlaisia lähestymistapoja, jotta jatkossa voidaan tarjota luotettavampia ja tunnettujen laatustandardien mukaisia tuotteita. Tässä diplomityössä esittelen tutkimusvaihetta, suunnitteluprosessia sekä toteutustapoja toiminnallisesti tärkeän, REST-arkkitehtuurimallia noudattavan webrajapinnan toteuttamiseksi Invian Oy:n DomaCare-toiminnanohjausjärjestelmässä. Tänä päivänä DomaCare on yksi Suomen terveydenhuoltoalan nopeimmin kasvavista ja kehittyvistä ohjelmistoratkaisuista. Sitä käyttävätkin tuhannet tyytyväiset terveydenhuollon ammattilaiset päivittäin ympäri Suomen. DomaCare on monipuolinen asiakas- ja toiminnanohjausjärjestelmä, joka on suunniteltu erityisesti sosiaalialoille. Diplomityössäni kuvaan verkkopohjaisten järjestelmien arkkitehtuurisuunnittelun sekä REST-arkkitehtuurimallin teoreettista puolta. Lisäksi tuon opinnäytetyössäni esille kehitystyöhön tarvittavan ympäristön ja työkalut sekä toiminta- ja sekvenssikaaviot kullekin käyttötapaukselle, jotta se tukisi yleistä järjestelmän ymmärtämistä korkeammalla abstraktiotasolla. Lisäksi esittelen tutkimuksessani kaikki toteutetut yksikkötestit kussakin käyttötapauksessa sekä lopuksi myös ne lähestymistavat, joita käytettiin systeemin vahvistamiseksi. Päädyn johtopäätökseen, että diplomityössäni esitellyt kirjallisuuskatsaus, toteutus ja yksiköiden testeistä saadut tulokset täyttivät tämän tutkimuksen tavoitteet

Biodiesel production from high FFA rubber seed oil using waste cockles

A two-step heterogeneous catalyzed process of high free fatty acids (FFA) rubber seed oil was conducted to produce biodiesel in lab scale. Acid esterification process was first used to reduced the high FFA rubber seed oil from 78.9% to below 1%. The low cost cockle shell was utilized as a source of CaO heterogeneous catalyst by calcination process and its effect on transesterification process was studied. The optimum yield of 88.06% was obtained for the final product of biodiesel under optimal conditions of 16:1 molar ratio of methanol to oil, 9% catalyst weight percentage with 3 hours reaction time. All fuel properties were analysed according to the ASTM D 6751 standard and found within the requirements