109 research outputs found

    Bit-error-rate Optimization for CDMA Ultra-wideband System Using Generalized Gaussian Approach

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    Ultra-wideband is a wireless technology arisen for future high speed multimedia applications. It can provide data rate in excess of Gigabits per second by transmitting impulse signal through the free space. However, the ultra-wideband indoor channel models proposed by the IEEE P802.15.3a suffer long multipath propagation. Due to this multipath effect, several studies have been done to improve the bit-error-rate performance of the ultra-wideband system in the existence of severe interference. Yet, most of the proposed algorithms were formulated based on the Gaussian distribution, which is not true in ultra-wideband. In this paper, we first analyze the statistical behavior of the CDMA-UWB signal by applying the Kullback-Leibler divergence index. Based on the analysis, a non-Gaussian equalizer is developed by deriving an enhanced bit-error-rate optimization algorithm using the Generalized Gaussian approach. The proposed equalizer has been shown to achieve a performance gain of at least 1.5dB to 2dB over the other equalizers simulated under IEEE P802.15.3a channel models

    IT Portfolio Investment Evaluation on E-Commerce Solution Alternatives

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    Our study examines the group decision-making process and proposes a multi-criteria framework for e-commerce solution investment in information technology (IT) portfolios. First, the evaluation criteria that fit in the IT evaluation context are constructed. Second, the Fuzzy Analytic Hierarchy Process (FAHP) is employed to determine the weights of decision criteria and the benefit score to the company. Third, the Fuzzy Multiple Criteria Decision-Making (FMCDM) approach is used to synthesize the team decision. Finally, an empirical case of five proposed portal solutions in a car manufacturing company is used to exemplify the approach

    IoT-Based Indoor and Outdoor Self-Quarantine System for COVID-19 Patients

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    Even after two years since the declaration of the new virus Coronavirus Disease 19 (COVID-19), the reported cases are still considerably high in many countries, including Malaysia. The health authorities cannot monitor the health condition and track the location of every home-monitored patient at once due to many confirmed cases in a day. In order to overcome the shortage of manpower, an Internet of Things (IoT)-based self-quarantine system with Radio Frequency Identification (RFID) and Global Positioning System (GPS) tracking is proposed in this paper to monitor the health conditions of the Covid-19 patients and track their real-time location via mobile application. Biomedical sensors are used to measure health conditions such as temperature, pulse oximetry, and heart-rate monitor. In addition, the RFID readers are used to detect patients that intend to leave the quarantine area, and the GPS modules are used to track their actual geometrical location so that the authorities can take further action. The real-time data is automatically pushed to the cloud server for the authorities to remotely view the patient's health condition and location on the Google map using smart devices. Finally, a hardware prototype and a mobile application have been successfully developed in this project. The system is able to display the temperature, heartbeats, and blood oxygen saturation properly on a liquid crystal display (LCD) screen. All these measured values, together with the information from RFID detection and GPS location tracking, can be viewed on a smartphone

    IoT-based autonomous baby monitoring system using mobile app control

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    In this modern world, almost 80% of parents have to work in order to balance their financial demands. The probability of providing better childcare, especially for babies is reducing. Although hiring a guardian or sending babies to daycare centers can temporarily solve the issue, it does not reduce the anxiety and stress of the parents due to more and more child abuses being reported every year. During this Covid19 pandemic, the need for an alternative better solution is urgent when some parents are forced to undergo quarantine for at least a few weeks. In this paper, we propose to develop a long-ranged baby monitoring and controlling system. The system consists of hardware architecture that is inter-connected with an IoT network to monitor the real-time condition of the baby such as crying, awakening and cleanliness, and its surrounding environment such as temperature, humidity and motion. In the proposal, the overall system operation involves four different phases: data collection, information sharing and processing, output display and notification, and user control. At the end of the project, a prototype has been successfully constructed to collect the monitoring data, and then share and display them to the users accurately via mobile app. In addition, users can also remotely perform basic control over any components or devices that are connected to the system

    Securing mhealth applications with grid-based honey encryption

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    Mobile healthcare (mHealth) application and technologies have promised their cost-effectiveness to enhance healthcare quality, particularly in rural areas. However, the increased security incidents and leakage of patient data raise the concerns to address security risks and privacy issues of mhealth applications urgently. While recent mobile health applications that rely on password-based authentication cannot withstand password guessing and cracking attacks, several countermeasures such as One-Time Password (OTP), gridbased password, and biometric authentication have recently been implemented to protect mobile health applications. These countermeasures, however, can be thwarted by brute force attacks, man-in-the-middle attacks and persistent malware attacks. This paper proposed grid-based honey encryption by hybridising honey encryption with grid-based authentication. Compared to recent honey encryption limited in the hardening password attacks process, the proposed grid-based honey encryption can be further employed against shoulder surfing, smudge and replay attacks. Instead of rejecting access as a recent security defence mechanism in mobile healthcare applications, the proposed Grid-based Honey Encryption creates an indistinct counterfeit patient's record closely resembling the real patients' records in light of each off-base speculation legitimate password

    Interpretation Structure Modeler for FOL

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    Import 05/08/2014Obsahem této diplomové práce je analýza a návrh systému pro podporu výuky předmětu Matematická logika. Vytvářený systém se bude týkat problematiky 3D vizualizace úlohy na hledání modelu množiny formulí v predikátové logice prvního řádu a modelování důležitých vlastností relací. Nástroj bude také obsahovat nápovědu pro vytvoření modelu množiny. V první části práce, je čtenář seznámen s teoretickými základy z dané oblasti, na které plynule navazuje specifikace požadavků na nový systém. Dále je text práce zaměřen především na analýzu a návrh jednotlivých částí systému, která je doplněna o třídní a sekvenční diagramy UML.The goal of this thesis is to Provide design and analysis of a new system, which could then be used as a teaching tool in subject called Mathematical Logic. The new system will consist of two main parts. The first part will be dealing with the problem of 3D visualization of formula set models. The second part will include an environment for modeling important properties of relations. Our system will also include an aid for creating formula set models. In the first part of the thesis we focus on theoretical background and requirement specification for the new system. Following parts ot the thesis are mainly focused on analysis and design of individual system parts, accompanied with class and sequence UML diagrams.460 - Katedra informatikydobř

    Nutrient supply in the Southern East China Sea after Typhoon Morakot

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    Author Posting. © Sears Foundation for Marine Research, 2013. This article is posted here by permission of Sears Foundation for Marine Research for personal use, not for redistribution. The definitive version was published in Journal of Marine Research 71 (2013): 133-149, doi:10.1357/002224013807343425.Recent studies show that typhoons have profound effects on phytoplankton assemblages along their tracks, but it is difficult to quantitatively estimate nutrient supply after a typhoon's passage due to a lack of nutrient information before and after the arrival of a typhoon. During the passage of Typhoon Morakot (July 22 to Aug. 26, 2009), we conducted pre- and post-typhoon field cruises to study nutrient supply in the Southern East China Sea (SECS). The results showed nitrate and phosphate supplies to the water column in the SECS after the typhoon's passage were 5.6 × 1011 g-N/day and 7.8 × 1010 g-P/day which were significantly higher than those before the typhoon occurred (nitrate supply = 1 × 109 g-N/day, phosphate supply = 1.6 × 108 g-P/day). We conclude from this data, and after consulting the available physical data, that the highest nitrate concentration was caused by strong upwelling and/or vertical mixing, and input of nutrient-replete terrestrial waters. The nitrate and phosphate input related to the passage of Typhoon Morakot can account for approximately 86% and 87% of summer nitrate and phosphate supplies to the southern East China Sea.This research was supported by the Top University Program and the National Science Council (NSC101-2116M-110- 001, NSC101-2611-M-110-015-MY3, NSC100-2119-M-110-003, NSC98-2611-M-019-014-MY3, NSC NSC98-2611-M-002-019-MY3) of Taiwan to C.-C. Hung, G.-C.Gong and S. Jan

    Corrigendum to “Nutrient supply in the Southern East China Sea after Typhoon Morakot”

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    Author Posting. © Sears Foundation for Marine Research, 2013. This article is posted here by permission of Sears Foundation for Marine Research for personal use, not for redistribution. The definitive version was published in Journal of Marine Research 71 (2013): 451-452, doi:10.1357/002224013812587609

    Genome-Wide Gene Expression Analysis Implicates the Immune Response and Lymphangiogenesis in the Pathogenesis of Fetal Chylothorax

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    Fetal chylothorax (FC) is a rare condition characterized by lymphocyte-rich pleural effusion. Although its pathogenesis remains elusive, it may involve inflammation, since there are increased concentrations of proinflammatory mediators in pleural fluids. Only a few hereditary lymphedema-associated gene loci, e.g. VEGFR3, ITGA9 and PTPN11, were detected in human fetuses with this condition; these cases had a poorer prognosis, due to defective lymphangiogenesis. In the present study, genome-wide gene expression analysis was conducted, comparing pleural and ascitic fluids in three hydropic fetuses, one with and two without the ITGA9 mutation. One fetus (the index case), from a dizygotic pregnancy (the cotwin was unaffected), received antenatal OK-432 pleurodesis and survived beyond the neonatal stage, despite having the ITGA9 mutation. Genes and pathways involved in the immune response were universally up-regulated in fetal pleural fluids compared to those in ascitic fluids. Furthermore, genes involved in the lymphangiogenesis pathway were down-regulated in fetal pleural fluids (compared to ascitic fluid), but following OK-432 pleurodesis, they were up-regulated. Expression of ITGA9 was concordant with overall trends of lymphangiogenesis. In conclusion, we inferred that both the immune response and lymphangiogenesis were implicated in the pathogenesis of fetal chylothorax. Furthermore, genome-wide gene expression microarray analysis may facilitate personalized medicine by selecting the most appropriate treatment, according to the specific circumstances of the patient, for this rare, but heterogeneous disease

    Interference Suppresion For UWB Receivers Using Adaptive Minimum BIT Error Rate Equalizer

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    In this thesis, our goal is suppress ISI and MAI in order to improve bit-error-rate (BER) performance of the UWB receivers. In the past, many receivers habe been proposed to overcome this problem.The most common approach used is the minimum mean square error (MMSE)
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