Multi-Criteria Decision Making using TOPSIS Method for Battery Type Selection in Hybrid Propulsion System

In the maritime sector, many improvements are performed on ship propulsion system. The hybrid propulsion system (HPS) is one of the innovations in the marine sector, considering International Maritime Organization (IMO) energy efficiency measures. The main objectives of the HPS are reduction in fuel consumption, maintenance costs, and minimization of the emissions of gases that harm the environment. The IMO International Convention for the Prevention of Pollution from Ships (MARPOL) Annex VI “Prevention of Air Pollution from Ships” determines nitrogen oxide, sulfur oxide, and particulate matter limits emitted from marine vessels. These limitations will be met with the HPS to be established on marine vessels. Batteries, an Energy Storage System (ESS), are used to drive electric motors, part of the HPS equipment. In this study, battery types are evaluated in terms of their chemical properties, capacities, volumes, weights, energies, specific energies, costs, and life cycle by TOPSIS method and the most suitable battery for the HPS is selected. According to the results, the highest rank (0.643127638) for the HPS is obtained from lithium iron phosphate (LFB) battery that has 200 Ah capacity, 30.55-liter volume, 27.7 kg weight, 92.42 Wh/kg energy density, 987 $/kWh cost, and 400~13,000 life cycle. This study will be a good source for researchers and maritime sector stakeholders, whose studies regard Energy Storage Systems, especially batteries on the HPS in marine vessels

A Revelatory Case Study for the Emergence of Powerships: The Floating Power Plant Innovation for Rural Electrification

The existence of energy is essential to countries striving to survive, both socially and economically. In this context, countries establish different types of power plants and use alternative energy resource,s such as solar and wind power, to meet their energy needs. Establishing power plants and using alternative energy resources are tough for some regions, such as Middle Eastern, African, and Asian countries. Thereby Powerships have been developed due to the consideration that these countries suffer from energy deficiency and encounter difficulties in building land power plants. In this study, the emergence of Powerships, providing electricity to energy-deficient countries and the successful launch strategies, are investigated. A single revelatory case study concept is used to understand what exactly the Powerships are, where they operate, positive and negative situations encountered during operation, as well as economic benefits compared to other systems. In this context, together with the intensive literature review, semi-structured interview questions are prepared for several company officials and former employees and detailed evaluations are described in the Powerships operation process. Semi-structured interview questions results are evaluated and discussed with a view to understanding how the company has successfully launched its innovative product to the energy market. This article will, we hope, represent a significant resource for experts, academics, and companies working on floating energy power plants in the future

General Framework and Novel Transceiver Architecture based on Hybrid Beamforming for NOMA in Massive MIMO Channels

Massive MIMO and non-orthogonal multiple access (NOMA) are crucial methods for future wireless systems as they provide many advantages over conventional systems. Power domain NOMA methods are investigated in massive MIMO systems, whereas there is little work on integration of code domain NOMA and massive MIMO which is the subject of this study. We propose a general framework employing user-grouping based hybrid beamforming architecture for mm-wave massive MIMO systems where NOMA is considered as an intra-group process. It is shown that classical receivers of sparse code multiple access (SCMA) and multi-user shared access (MUSA) can be directly adapted. Additionally, a novel receiver architecture which is an improvement over classical one is proposed for uplink MUSA. This receiver makes MUSA preferable over SCMA for uplink transmission with lower complexity. We provide a lower bound on achievable information rate (AIR) as a performance measure. We show that code domain NOMA schemes outperform conventional methods with very limited number of radio frequency (RF) chains where users are spatially close to each other. Furthermore, we provide an analysis in terms of bit-error rate and AIR under different code length and overloading scenarios for uplink transmission where flexible structure of MUSA is exploited.Comment: Partially presented at IEEE ICC 2020 Workshop on NOMA for 5G and Beyond and to be submitted to IEEE Transactions on Communication

Computer-aided analysis of English punctuation on a parsed corpus: the special case of comma

Ankara : Department of Computer Engineering and Information Science and the Institute of Engineering and Science of Bilkent University, 1996.Thesis (Master's) -- Bilkent University, 1996.Includes bibliographical references leaves 51-56.Punctuation, an orthographical component of language, has usually been ignored by most research in computational linguistics over the years. One reason for this is the overall difficulty of the subject, and another is the absence of a good theory. On the other hand, both ‘conventional’ and computational linguistics have increased their attention to punctuation in recent years because it has been realized that true understanding and processing of written language will be almost impossible if punctuation marks are not taken into account. Except the lists of rules given in style manuals or usage books, we know little about punctuation. These books give us information about how we should punctuate, but they are generally silent about the actual punctuation practice. This thesis contains the details of a computer-aided experiment to investigate English punctuation practice, for the special case of comma (the most significant punctuation mark) in a parsed corpus. The experiment attempts to classify the various uses of comma according to the syntax-patterns in which comma occurs. The corpus (Penn Treebank) consists of syntactically annotated sentences with no part-of-speech tag information about individual words, and this ideally seems to be enough to classify ‘structural’ punctuation marks.Bayraktar, MuratM.S

Revisiting Export-Output Growth Nexus: Findings from Granger Causality and Leveraged Bootstrap Approach for Japan

The study investigates the causal nexus between export and output growth of Japan to identify the validity of the export-led growth (ELG) hypothesis in a modified theoretical setting. The study is unique in the sense that it takes the Japanese crisis of 1992 into account and also addresses the possible income identification problem that most of the earlier studies largely ignored. The direction and extent to which the explanatory variables, namely, exports, imports, capital expenditure, total labor productivity and a dummy representing the crisis affect the industrial output are investigated employing both Granger causality and Leveraged Bootstrap Simulation Techniques. Both of the approaches suggest that the relationship between exports and output growth is not unidirectional which implies that export promotion cannot be regarded as a tool to promote economic growth for Japan that has important implications for policymakers to set suitable strategies to boost its economic growth

Autoregressive Attention Neural Networks for Non-Line-of-Sight User Tracking with Dynamic Metasurface Antennas

User localization and tracking in the upcoming generation of wireless networks have the potential to be revolutionized by technologies such as the Dynamic Metasurface Antennas (DMAs). Commonly proposed algorithmic approaches rely on assumptions about relatively dominant Line-of-Sight (LoS) paths, or require pilot transmission sequences whose length is comparable to the number of DMA elements, thus, leading to limited effectiveness and considerable measurement overheads in blocked LoS and dynamic multipath environments. In this paper, we present a two-stage machine-learning-based approach for user tracking, specifically designed for non-LoS multipath settings. A newly proposed attention-based Neural Network (NN) is first trained to map noisy channel responses to potential user positions, regardless of user mobility patterns. This architecture constitutes a modification of the prominent vision transformer, specifically modified for extracting information from high-dimensional frequency response signals. As a second stage, the NN's predictions for the past user positions are passed through a learnable autoregressive model to exploit the time-correlated channel information and obtain the final position predictions. The channel estimation procedure leverages a DMA receive architecture with partially-connected radio frequency chains, which results to reduced numbers of pilots. The numerical evaluation over an outdoor ray-tracing scenario illustrates that despite LoS blockage, this methodology is capable of achieving high position accuracy across various multipath settings.Comment: 5 pages, 3 figures, accepted for presentation by 2023 IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP 2023

Revisiting Export-Output Growth Nexus: Findings from Granger Causality and Leveraged Bootstrap Approach for Japan

The study investigates the causal nexus between export and output growth of Japan to identify the validity of the export-led growth (ELG) hypothesis in a modified theoretical setting. The study is unique in the sense that it takes the Japanese crisis of 1992 into account and also addresses the possible income identification problem that most of the earlier studies largely ignored. The direction and extent to which the explanatory variables, namely, exports, imports, capital expenditure, total labor productivity and a dummy representing the crisis affect the industrial output are investigated employing both Granger causality and Leveraged Bootstrap Simulation Techniques. Both of the approaches suggest that the relationship between exports and output growth is not unidirectional which implies that export promotion cannot be regarded as a tool to promote economic growth for Japan that has important implications for policymakers to set suitable strategies to boost its economic growth

The role of simple elbow dislocations in cubitus valgus development in children

We investigated the functional and radiological outcomes of conservatively treated simple traumatic elbow dislocations and subsequent incidence of cubitus valgus development in children. Eleven patients (one female, ten male; mean age 9.8 years, range seven to 12 years) who presented to our hospital with simple elbow dislocations and were conservatively treated between July 2008 and September 2010 were included in the study. All were posterolateral closed dislocations. None of the patients had accompanying elbow fractures. All patients had pre- and postoperative radiographic examinations. The carrying angle of the involved elbow was measured and compared to the contralateral non-injured elbow during follow-up. The incidence and severity of cubitus valgus development was assessed. The functional and clinical outcomes were evaluated using the Mayo Elbow Performance Scale. The mean monitoring period was 24.3 months (range 19-30 months). All patients had satisfactory good and excellent results (85-100 points; mean 96.8 points) according to the Mayo Elbow Performance Scale. The final average elbow flexion was 137A degrees (range, 130-145A degrees) and average extension was 8.6A degrees (range 0-20A degrees) with full supination and pronation in traumatic elbow. Four patients (36.4 %) had an average increase (cubitus valgus) of 14.5A degrees (10-20A degrees) in carrying angle compared to the other elbow. While isolated traumatic dislocation of the elbow is uncommon among children, it can be successfully treated by urgent closed reduction, proper fixation of the elbow and appropriate timely rehabilitation. However, it should be considered that some patients may develop cubitus valgus deformity in a later period. Therefore, each patient with a simple traumatic elbow dislocation should be followed, and the parents should be informed of the potential for any deformity development

Comparison of two pandemics: H1N1 and SARS-CoV-2

OBJECTIVE: We aimed to compare the clinical, epidemiological, and prognostic features of the H1N1 pandemic in 2009 and the severe acute respiratory syndrome coronavirus 2 pandemic in 2020. METHODS: This retrospective study involved subjects from seven centers that were admitted and found to be positive for H1N1 or COVID-19 real-time polymerase chain reaction test. RESULTS: A total of 143 patients with H1N1 and 309 patients with COVID-19 were involved in the study. H1N1 patients were younger than COVID-19 ones. While 58.7% of H1N1 patients were female, 57.9% of COVID-19 patients were male. Complaints of fever, cough, sputum, sore throat, myalgia, weakness, headache, and shortness of breath in H1N1 patients were statistically higher than in COVID-19 ones. The duration of symptoms until H1N1 patients were admitted to the hospital was shorter than that for COVID-19 patients. Leukopenia was more common in COVID-19 patients. C-reactive protein levels were higher in COVID-19 patients, while lactate dehydrogenase levels were higher in H1N1 ones. The mortality rate was also higher in H1N1 cases. CONCLUSIONS: The severe acute respiratory syndrome coronavirus 2 pandemic is a major public health problem that continues to affect the world with its high rate of contagion. In addition, no vaccines or a specific drug for the benefit of millions of people have been found yet. The H1N1 pandemic is an epidemic that affected the whole world about ten years ago and was prevented by the development of vaccines at a short period. Experience in the H1N1 pandemic may be the guide to prevent the COVID-19 pandemic from a worse end