2,811 research outputs found

    A model of case implementation and an experience of unsuccessful case adoption

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    Computer-Aided Software Engineering (CASE) is a revolutionary technology that seeks to automate the software development process. Current literature reports on many successes of CASE adoption Despite of such successes, many organisations are experiencing difficulties in implementing CASE technology . Even many powerful CASE tools have become 'shelfware'. It is argued that the benefits of CASE are unlikely to be realised, unless it is introduced based on a sound implementation plan This article presents a conceptual model to introduce CASE technology within a MIS department Such a plan faciliiaus change in software culture and management practice and enables management to deal with confusion and skepticism prior to its occurrence. Furthermore, a case study is described that focuses on a CASE implementation that failed to achieve its purpose The reasons for the failure are critically examined and explained in the light of the model

    Single-, Dual- and Triple-band Frequency Reconfigurable Antenna

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    The paper presents a frequency reconfigurable slot dipole antenna. The antenna is capable of being switched between single-band, dual-band or triple-band operation. The antenna incorporates three pairs of pin-diodes which are located within the dipole arms. The antenna was designed to operate at 2.4 GHz, 3.5 GHz and 5.2 GHz using the aid of CST Microwave Studio. The average measured gains are 1.54, 2.92 and 1.89 dBi for low, mid and high band respectively. A prototype was then constructed in order to verify the performance of the device. A good level of agreement was observed between simulation and measurement

    An Electronically Reconfigurable Patch Antenna Design for Polarization Diversity with Fixed Resonant Frequency

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    In this paper, an electronically polarization reconfigurable circular patch antenna with fixed resonant frequency operating at Wireless Local Area Network (WLAN) frequency band (2.4-2.48 GHz) is presented. The structure of the proposed design consists of a circular patch as a radiating element fed by coaxial probe, cooperated with four equal-length slits etched on the edge along x-axis and y-axis. A total of four switches was used and embedded across the slits at specific locations, thus controlled the length of the slits. By activating and deactivating the switches (ON and OFF) across the slits, the current on the patch is changed, thus modifying the electric field and polarization of the antenna. Consequently, the polarization excited by the proposed antenna can be switched into three types, either linear polarization, left-hand circular polarization or right-hand circular polarization. This paper proposes a simple approach that able to switch the polarizations and excited at the same operating frequency. Simulated and measured results of ideal case (using copper strip switches) and real case (using PIN diode switches) are compared and presented to demonstrate the performance of the antenna

    Near infrared spectroscopy (NIRS) applications in medical: non-invasive and invasive leukemia screening

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    Near Infrared Spectroscopy (NIRS) has been applied as analytical tool in numerous field of study due to its ability in non-invasive application. NIRS with the ability in providing the information on biological molecules shows a high potential as a diagnosis tool in medical as diseased related to biochemistry changes of the cell and tissue. This paper reviewed the application of NIR spectroscopy in leukemia screening and in other medical application. General comparison between invasive and non-invasive NIR spectroscopy method is provided. The author also proposed a new non-invasive NIRS method in leukemia screening and compared it with the previous invasive NIRS method

    Optimum transmitter receiver ratio for maximum wireless energy transfer

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    Due to high demand of using cordless mobile device, the interest in wireless energy transfer (WET) has been growth intensively. This paper presented a method to obtained optimum transmitter receiver ratio for maximum performance of WET system using different initial antenna size at various distance. An optimized algorithm has been developed to determine the optimum ratios that yield the highest wireless transfer efficiency (WTE) at near field communication (NFC) frequency, 13.56MHz. 30mm Ă— 30mm single square loop antenna is used as initial size of both transmitter and receiver using FR4 with operating distance = 50mm. Operating distance and initial size of the antenna will be varied and the effect to the WTE will be studied using Matlab, verified using Microsoft Studio CST. At distance = 50mm and initial size of the antenna = 30mm Ă— 30mm, optimum transmitter to receiver ratio equal to 1:3 is obtained. The pattern of optimum transmitter receiver ratio between Matlab and CST has met an agreement. This research limited to integer transmitter receiver ratio used only and no decimal number being involved in magnify the transmitter size

    Glucose detection in blood using near-infrared spectroscopy: significant wavelength for glucose detection

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    World Health Organization (WHO) stated in 2004, about 347 million people suffered from diabetes and from this statistic, about 3.4 million died from the complication of kidney failure, heart attack, body part amputation and adequately reported suffered from blindness. There are several non-invasive techniques in measuring the blood glucose level developed nowadays and among the popular technique is the near-infrared (NIR) measurement, ultrasonic sensor implementation, multisensory systems, absorbance of transmittance, bio-impedance, voltage intensity, and thermography. Among these techniques, there are several approaches that displayed a lot of potential, nonetheless some of them have produced unsatisfying results. The NIR technique has been applied in some of previous research, however the wavelength used vary for different researcher. There are several points of views on the significant wavelength range that contains suitable information regarding the peaks of glucose in blood. This paper is focusing on the experimental data collection using the near-infrared spectroscopy technique. This paper furthermore discussing on determine the significant peaks of glucose that is suitable to be used as the indicator of the glucose in blood. The highest significant peaks of blood glucose detected from the range around 1450nm and 1930nm

    The Influence of Risk on The Performance Project of Framework Agreement Construction

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    The contract is an important aspect that is crucial in the implementation of construction projects. Framework agreement is one of the model contracts that are still limited implementation in the construction world in Indonesia. This study aims to assess the application of Framework agreement in the construction field, especially from the aspect of risk; it starts from identification to the risk allocation of the aspect of construction contracts. The research is done in the form of a survey by capturing the opinions or perceptions, experiences, and attitudes of respondents consisted of contracting, procurement, vendor, and the project owner. From the results of the study note that the most influential risk level is variable Fossil (X8), Testing (X9), Termination of employment (X16), Delay Testing (X18), handover of some of the work ((X20), Procedure variation (X28), the Right Contractor to Halt Work (X33), the risk of service users (X36), the consequences of the risk of service users (X37) and exemption from the obligation to force majeure (X44)

    Single channel magnetic induction spectroscopy technique for fetal acidosis detection

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    Current fetal acidosis diagnosis needs an invasive measurement which required a doctor to puncture fetal scalp to acquire blood pH. This method introduced risk to the fetal which fetal scalp may bruise and infected. This paper discusses a noninvasive method employing a single channel magnetic induction spectroscopy technique as an alternative method to diagnose acidosis in fetal without puncturing the fetal scalp. The studies are based on numerical simulation models to investigate the most feasible sensor coil that is sensitive and effective to be implemented in hardware setup as the shape of coil influences directly the sensing performance of the magnetic induction spectroscopy system. The study has found that the circular coil is more sensitive than linear coil. The system tested with different pH samples to mimic the blood pH value. The result is very promising with good correlation approaching 1 has been achieved. Therefore, magnetic induction spectroscopy technique has good opportunity to be applied as an alternative method to detect acidosis in the fetal with circular coil is performed as the best sensing coils for MIS hardware

    Stroke aetiological classification reliability and effect on trial sample size : systematic review, meta-analysis and statistical modelling

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    BackgroundInter-observer variability in stroke aetiological classification may have an effect on trial power and estimation of treatment effect. We modelled the effect of misclassification on required sample size in a hypothetical cardioembolic (CE) stroke trial.MethodsWe performed a systematic review to quantify the reliability (inter-observer variability) of various stroke aetiological classification systems. We then modelled the effect of this misclassification in a hypothetical trial of anticoagulant in CE stroke contaminated by patients with non-cardioembolic (non-CE) stroke aetiology. Rates of misclassification were based on the summary reliability estimates from our systematic review. We randomly sampled data from previous acute trials in CE and non-CE participants, using the Virtual International Stroke Trials Archive. We used bootstrapping to model the effect of varying misclassification rates on sample size required to detect a between-group treatment effect across 5000 permutations. We described outcomes in terms of survival and stroke recurrence censored at 90days.ResultsFrom 4655 titles, we found 14 articles describing three stroke classification systems. The inter-observer reliability of the classification systems varied from fair' to very good' and suggested misclassification rates of 5% and 20% for our modelling. The hypothetical trial, with 80% power and alpha 0.05, was able to show a difference in survival between anticoagulant and antiplatelet in CE with a sample size of 198 in both trial arms. Contamination of both arms with 5% misclassified participants inflated the required sample size to 237 and with 20% misclassification inflated the required sample size to 352, for equivalent trial power. For an outcome of stroke recurrence using the same data, base-case estimated sample size for 80% power and alpha 0.05 was n=502 in each arm, increasing to 605 at 5% contamination and 973 at 20% contamination.ConclusionsStroke aetiological classification systems suffer from inter-observer variability, and the resulting misclassification may limit trial power.Trial registrationProtocol available at reviewregistry540.Peer reviewe

    3-4.5 ÎĽm continuously tunable single mode VECSEL

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    We present continuously tunable Vertical External Cavity Surface Emitting Lasers (VECSEL) in the mid-infrared. The structure based on IV-VI semiconductors is epitaxially grown on a Si-substrates. The VECSEL emit one single mode, which is mode hop-free tunable over 50-100nm around the center wavelength. In this work, two different devices are presented, emitting at 3.4ÎĽm and 3.9ÎĽm, respectively. The lasers operate near room temperature with thermoelectric stabilization. They are optically pumped, yielding an output power >10mWp. The axial symmetric emission beam has a half divergence angle of <3.3
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