56271 research outputs found
Sort by
Eco-efficiency of electric vehicles in the United States:a life-cycle assessment based principal component analysis
No full textTezin basılısı İstanbul Şehir Üniversitesi Kütüphanesi'ndedir
Teachers' professional development in the digitized world
No full textProfessional development for in-service English language teachers has increasingly become a need in higher education not only in Turkey but across the world. Due to the limited time teachers have and the distance between the source of service and the potential participants, using digitized activities and materials have naturally become a necessity. The purpose of this research is to report the potential impact of the course described below and discuss the role of blended learning experience of professional development on the participating teachers. The theoretical background of the study is experiential learning initiated by Kolb and socio-constructivist learning theory by Vygotsky in that both theories highlight the role of experiencing the change and focus on personal meanings and learning with and from others in real and online environments
A wide-current range switched capacitor DC-DC converter utilizing frequency, interleaving and switch-size scaling techniques
No full textTezin basılısı İstanbul Şehir Üniversitesi Kütüphanesi'ndedir.DC-DC converters are one of the main components of any system. Since analog and
digital sub-modules in SoC require different supply voltages, large number of DC-DC
converter are used to provide supply voltages for each module from the global input
voltage source.
DC-DC converters are divided into two main types; linear and switching regulators. As
the drop between the global input source and required voltage increases, linear regula-
tors suffer from high losses and consequently achieve low efficiency compared to switching
regulators. Since integration is one of the main objectives, switched capacitor DC-DC
converters are more preferable compared inductor based regulators. SC DC-DC regula-
tors eliminate the bulky and costly inductor and can be integrated fully on-chip to be
used in sensor networks, energy harvesters and bio-sensors.
In this dissertation, a switched capacitor DC-DC converter, which can directly convert
input voltage of 3.3V to five different output voltages, is presented. Different design
techniques are used in the design to improve efficiency over a large output current range,
reduce output ripple, increase response time and reduce the overall cost.
To improve efficiency, the converter uses a combination of frequency, interleaving and
switch width scaling techniques in a feedback loop that respond to the output load and
current conditions. The loop consists of a four-phase clock generator, a clock divider,
high speed dynamic comparators and a decision making unit. In order to reduce the
output ripple, the converter uses four interleavers and frequency scaling. A decision
making circuit is included to switch the converter into high response speed mode. Off-
chip components were eliminated to minimize the cost of the design.Declaration of Authorship ii
Abstract iii
Öz iv
Acknowledgments v
List of Figures vii
List of Tables viii
1 Introduction 1
1.1 Power management for modern Soc . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Thesis Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2 Background Theories 3
2.1 Classification of DC-DC converters . . . . . . . . . . . . . . . . . . . . . . 3 2.1.1 Linear Regulators . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1.2 Inductor-Based Switching DC-DC converters. . . . . . . . . . . . . 4
2.1.3 Switched capacitor DC-DC converters . . . . . . . . . . . . . . . . 5
2.2 Basic operation of switched capacitor Converters . . . . . . . . . . . . . . 7
2.3 Loss mechanism in switched capacitor Converters . . . . . . . . . . . . . . 8
2.3.1 Conduction loss [charge transfer loss] . . . . . . . . . . . . . . . . . 8
2.3.2 Bottom plate and parasitic capacitor loss. . . . . . . . . . . . . . . 8
2.3.3 Gate-drive loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.3.4 Control circuit loss . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.3.5 Output Ripple . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.3.6 Summary of losses . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.4 Control Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.4.1 Pulse frequency modulation (PFM) technique . . . . . . . . . . . . 13
2.4.2 Switch width modulation technique . . . . . . . . . . . . . . . . . . 14
2.4.3 Switch width modulation technique . . . . . . . . . . . . . . . . . . 14
3 Implementation of Switched Capacitor DC-DC Converter 17 3.1 Architecture of the converter . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.2 Multi-gain switched capacitor converter. . . . . . . . . . . . . . . . . . . . 18
3.2.1 Switch type selection . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.2.2 Capacitor selection . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.3 Feedback control loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3.3.1 Frequency Scaling and frequency divider. . . . . . . . . . . . . . . 26
3.3.2 Interleavers and switch scaling. . . . . . . . . . . . . . . . . . . . . 27
3.3.3 Decision making unit . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4 Layout 30
5 Measurements and Simulations 33
6 Conclusion 41
Bibliography 4
Multilevel reed-solomon codes for PMR channels
No full textReed-Solomon (RS) codes are commonly utilized in magnetic recording systems to correct error bursts. A soft-output Viterbi algorithm (SOVA) is a commonly used detector to provide soft information to error-correcting decoders. We propose a novel architecture of a multilevel interleaved RS coding scheme that not only provides better performance but also has less complexity than an equivalent RS code. This architecture implements an error event detector using the soft information generated by the SOVA detector. The performance and complexity of the decoding technique are compared with the well-known soft-decoding techniques, such as generalized minimum distance decoding and Chase decoding techniques
Combined application of multi-criteria optimization and life-cycle sustainability assessment for optimal distribution of alternative passenger cars in US
No full textThis research aims to advance the existing sustainability assessment framework for alternative passenger cars with a combination of life-cycle sustainability assessment and multi-criteria decision-making. To this end, sixteen macro-level sustainability impacts are evaluated for seven different vehicle types: internal combustion vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles with all-electric ranges of 16, 32, 48, and 64 km of electric powered drive, and battery electric vehicles. Additionally, two battery charging scenarios are considered in this analysis with respect to plug-in hybrid electric vehicles and battery electric vehicles; Scenario 1 is based on existing electric power infrastructure in the U.S., while Scenario 2 is an extreme scenario in which electricity to power battery electric vehicles and plug-in hybrid electric vehicles is generated entirely via solar charging stations. In this study, optimal vehicle distributions are calculated based on the environmental, social, and economic impacts of all vehicle types for each scenario. Various distributions are presented in accordance with the relative importance assigned to each indicator, with different weighting scenarios applied to account for variability in decision-makers' priorities, such as the assignment of higher weights to socio-economic indicators (e.g. maximizing employment) and lower weights to environmental indicators (e.g. minimizing greenhouse gas emissions). In a balanced weighting case (i.e. when environmental and socio-economic indicators have equal importance) under Scenario 1, hybrid electric vehicles have the largest fleet share, comprising 91% of the optimal U.S. passenger car fleet, while internal combustion vehicles dominate the optimal fleet with 99.5% of the optimal fleet share when only socio-economic indicators are given priority. On the other hand, in a balanced weighting case under Scenario 2, the optimal U.S. passenger car fleet consists entirely (100%) of plug-in hybrid electric vehicles with 16 km of all-electric range. In the majority of the considered weighting scenarios, battery electric vehicles were not given any share of the optimal vehicle fleet. The proposed framework can be used as a practical decision-making platform when deciding which vehicle type to promote given each vehicle type's respective environmental, social, and economic impacts. Considering that decision makers are often highly influenced by the “silo effect”, i.e. a lack of communication among different agencies and departments (national or international), the proposed framework provides a holistic system-based approach to minimize the silo effect and can enhance the efficiency of future inter/cross/trans-disciplinary works. Furthermore, the outcomes of this study can pave the way for advancement in the state-of-the-art and state-of-the-practice of current sustainability research
A new database and protocol for image reuse detection
No full textThe use of visual elements of an existing image while creating new ones is a commonly observed phenomenon in digital artworks. The practice, which is referred to as image reuse, is not an easy one to detect even with the human eye, less so using computational methods. In this paper, we study the automatic image reuse detection in digital artworks as an image retrieval problem. First, we introduce a new digital art database (BODAIR) that consists of a set of digital artworks that re-use stock images. Then, we evaluate a set of existing image descriptors for image reuse detection, providing a baseline for the detection of image reuse in digital artworks. Finally, we propose an image retrieval method tailored for reuse detection, by combining saliency maps with the image descriptors
The lives of Muhammad
No full textKecia Ali delves into the many ways the Prophet's life story has been told from the earliest days of Islam to the present, by both Muslims and non-Muslims. Emphasizing the major transformations since the nineteenth century, she shows that far from being mutually opposed, these various perspectives have become increasingly interdependent
A comparative analysis of soft power in the mena region:the impact of ethnic, sectarian, and religious identity on soft power in Iraq and Egypt
No full textGenerating application layer IDS rules from cyber threat intelligence
No full textTezin basılısı, İstanbul Şehir Üniversitesi Kütüphanesi'ndedir.Variety and complexity of cyber threats are increasing in parallel with technological advancements in computer technologies. Therefore, it is getting harder to detect and ght cyber threats. Sharing of threat intelligence is a good way to grow immunity against various and complex threats, since it enables sharing parties to learn from others' experiences and knowledge, thereby to become alert to potential threats. XML-based standards TAXII, STIX and CybOX, of which development is led by MITRE, allow us to describe cyber threats in an extensive and standardized manner and to share them e ectively. The aim of this thesis is to convert STIX/CybOX formatted threat intelligence data to Suricata rules which can be readily implemented on Suricata IDS/IPS. To create rules for a Suricata engine based on latest threat information on a regular basis, will enable it to get familiar with emerging threats.Declaration of Authorship ii
Abstract iii
Öz iv
Acknowledgments vi
List of Figures viii
Abbreviations ix
1 Cyber Dimension of Life 1 1.1
Bene ts of Computer Technologies . . . . . . . . . . . . . . . . . . . . . . 1 1.2
Application Areas of Computer Technologies . . . . . . . . . . . . . . . . . 2
2 Cyber Threats and Countermeasures 3 2.1
Examples for Cyber Threats . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2
Security Measures Taken Against Cyber Threats . . . . . . . . . . . . . . 5 2.2.1
Anti-Malware Software Products . . . . . . . . . . . . . . . . . . . 5 2.2.2
Preventive Network Devices . . . . . . . . . . . . . . . . . . . . . . 5
3 Cyber Intelligence Sharing 7 3.1 Cyber Intelligence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.2
Importance of Sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.3
TAXII Protocol for CTI Sharing . . . . . . . . . . . . . . . . . . . . . . . 8 3.4
CybOX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.5
STIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4 Suricata 20
5 Related Work 23
6 Our Work 25
7 Conclusion 27
8 Future Work 2
Individual and culture-level components of survey response styles:a multi-level analysis using cultural models of selfhood
Get PDFVariations in acquiescence and extremity pose substantial threats to the validity of cross-cultural research that relies on survey methods. Individual and cultural correlates of response styles when using 2 contrasting types of response mode were investigated, drawing on data from 55 cultural groups across 33 nations. Using 7 dimensions of self-other relatedness that have often been confounded within the broader distinction between independence and interdependence, our analysis yields more specific understandings of both individual- and culture-level variations in response style. When using a Likert-scale response format, acquiescence is strongest among individuals seeing themselves as similar to others, and where cultural models of selfhood favour harmony, similarity with others and receptiveness to influence. However, when using Schwartz’s (2007) portrait-comparison response procedure, acquiescence is strongest among individuals seeing themselves as self-reliant but also connected to others, and where cultural models of selfhood favour self-reliance and self-consistency. Extreme responding varies less between the two types of response modes, and is most prevalent among individuals seeing themselves as self-reliant, and in cultures favouring self-reliance. As both types of response mode elicit distinctive styles of response, it remains important to estimate and control for style effects to ensure valid comparisons