Improved signal de-noising in underwater acoustic noise using S-transform: A performance evaluation and comparison with the wavelet transform

Sound waves propagate well underwater making it useful for target locating and communication. Underwater acoustic noise (UWAN) affects the reliability in applications where the noise comes from multiple sources. In this paper, a novel signal de-noising technique is proposed using S-transform. From the time-frequency representation, de-noising is performed using soft thresholding with universal threshold estimation which is then reconstructed. The UWAN used for the validation is sea truth data collected at Desaru beach on the eastern shore of Johor in Malaysia with the use of broadband hydrophones. The comparison is made with the more conventionally used wavelet transform de-noising method. Two types of signals are evaluated: fixed frequency signals and time-varying signals. The results demonstrate that the proposed method shows better signal to noise ratio (SNR) by 4 dB and lower root mean square error (RMSE) by 3 dB achieved at the Nyquist sampling frequency compared to the previously proposed de-noising method like wavelet transform. (C) 2017 Shanghai Jiaotong University. Published by Elsevier B.V

An Integrated Approach to Water-Energy Nexus with Multiple Energy Sources

The sustainable development of the entire world is confronting considerable challenges due to the tremendous expansion in energy demand that synchronizes with fresh water scarcity, vast depletion of conventional energy sources and climate change. Consequently, the necessity has emerged for creating suitable management strategies for existing water resources (e.g., wastewater treatment) and for integrating traditional energy sources with renewables (e.g., solar energy, wind energy, biofuels, etc.). The objective of this study is to develop a novel design framework of the water-energy nexus system, which optimized according to economic and environmental metrics using certain parameters (leading to deterministic optimization) and uncertain parameters (leading to stochastic optimization). The system comprises multiple energy sources, cogeneration process, and desalination technologies. Solar energy is incorporated to provide thermal power directly to a multi-effect distillation plant (MED) exclusively (to be more feasible economically), or to the entire system through a steam generator. Thus, MED is driven by direct solar energy, indirect solar energy (thermal energy storage), and surplus heat from the cogeneration process. Additionally, electric power production is intended to meet a reverse osmosis plant (RO) demand and the local electric grid (if it is connected to the system). The deterministic optimization problem is formulated as a multi-period Mixed Integer Non-Linear Programming (MINLP) to discretize operation period to track the diurnal fluctuations of solar energy. However, the stochastic optimization problem is formulated as a multiscenario MINLP problem that is a deterministic equivalent of a two-stage stochastic programming model for handling uncertainty in operational parameters (normal direct irradiance, fossil fuel price) through a finite set of scenarios. A case study is solved for water treatment and energy management for Eagle Ford Basin in Texas to obtain the maximum annual profit of the entire system. The long-term evaluation for the techno-economic performance of solar energy conversion systems is highly dependent on the availability of solar radiation data and their accuracy. This study offers hierarchical calculation methodologies to estimate solar irradiance values for a specific location under different sky conditions. A case study is solved to predict hourly direct normal irradiance for San Antonio city in Texas

Error Performance Analysis in Underwater Acoustic Noise With Non-Gaussian Distribution

There is a high demand for underwater communication systems due to the increase in current social underwater activities. The assumption of Gaussian noise allows the use of Traditional communication systems. However, the non-Gaussian nature of underwater acoustic noise (UWAN) results in the poor performance of such systems. This study presents an experimental model for the noise of the acoustic underwater channel in tropical shallow water at Desaru beach on the eastern shore of Johor in Malaysia, on the South China Sea with the use of broadband hydrophones. A probability density function of the noise amplitude distribution is proposed and its parameters defined. Furthermore, an expression of the probability of symbol error for binary signalling is presented for the channel in order to verify the noise effect on the performance of underwater acoustic communication binary signalling systems

Diurnal Variability Of Underwater Acoustic Noise Characteristics in Shallow Water

The biggest challenge in the underwater communication and target locating is to reduce the effect of underwater acoustic noise (UWAN). An experimental model is presented in this paper for the diurnal variability of UWAN of the acoustic underwater channel in tropical shallow water. Different segments of data are measured diurnally at various depths located in the Tanjung Balau, Johor, Malaysia. Most applications assume that the noise is white and Gaussian. However, the UWAN is not just thermal noise but a combination of turbulence, shipping and wind noises. Thus, it is appropriate to assume UWAN as colored rather than white noise. Site-specific noise, especially in shallow water often contains significant non-Gaussian components. The real-time noise segments are analyzed to determine the statistical properties such as power spectral density (PSD), autocorrelation function and probability density function (pdf). The results show the UWAN has a non-Gaussian pdf and is colored. Moreover, the difference in UWAN characteristics between day and night is studied and the noise power at night is found to be more than at the day time by around (3-8dB)

Prevalence of oral mucosal lesions in psoriatic patients: a controlled study

Objectives: This study aimed to investigate and compare the prevalence of oral mucosal lesions in a group of psoriatic patients and healthy subjects, and its correlation to multiple clinical parameters. Study design: 100 psoriatic patients and 100 closely matched controls underwent clinical oral examination. Oral lesions were diagnosed according to the criteria proposed by the World Health Organization (WHO). The patients filled the Hospital Anxiety and Depression (HAD) questionnaire and the Dermatology Life Quality Index (DLQI). The severity of psoriasis was assessed by the Psoriasis Area and Severity Index (PASI). Categorical variables were evaluated using Chi-square test or Fisher's exact test with overall significance set at p< 0.05. Results: Oral mucosal lesions were diagnosed in 43 (43%) psoriatic patients and 17 (17%) control subjects (p=0.000). Comparing psoriatic patients to control subjects the prevalence of fissured tongue (FT) was 35% vs. 13% (p=0.000); geographic tongue (GT) 17% vs. 9% (p=0.09); combination of FT and GT 5% vs. 5% (p=1.00); oral candidosis 3% vs. 0% (p=0.81); leukoedema 1% vs. 3% (p=0.62); physiologic melanin pigmentations 4% vs. 1% (p=0.37) respectively. The clinical type of psoriasis, duration of the disease, method of disease management (medicated vs. non-medicated for psoriasis), smoking habit, psychological status or the disease severity did not influence the prevalence of FT and GT. Psoriatic patients who experienced 'very large' to 'extremely large' adverse effect of psoriasis on their quality of life have significantly higher prevalence of GT (p=0.04). Conclusions: FT is significantly more common in psoriatic patients compared to controls; hence studies investigating the nature of this relationship are warranted. Oral health care providers should be aware of the predisposition of psoriatic patients to oral candidosis

Study of absorption loss effects on acoustic wave propagation in shallow water using different empirical models

Efficient underwater acoustic communication and target locating systems require detailed study of acoustic wave propagation in the sea. Many investigators have studied the absorption of acoustic waves in ocean water and formulated empirical equations such as Thorp's formula, Schulkin and Marsh model and Fisher and Simmons formula. The Fisher and Simmons formula found the effect associated with the relaxation of boric acid on absorption and provided a more detailed form of absorption coefficient which varies with frequency. However, no simulation model has made for the underwater acoustic propagation using these models. This paper reports the comparative study of acoustic wave absorption carried out by means of modeling in MATLAB. The results of simulation have been evaluated using measured data collected at Desaru beach on the eastern shore of Johor in Malaysia. The model has been used to determine sound absorption for given values of depth (D), salinity (S), temperature (T), pH, and acoustic wave transmitter frequency (f). From the results a suitable range, depth and frequency can be found to obtain best propagation link with low absorption loss

A Novel Algorithm for Predicting Antimicrobial Resistance in Unequal Groups of Bacterial Isolates

Choosing antimicrobials is a common dilemma when the expected rate of bacterial resistance is high. The observed resistance values in unequal groups of isolates tested for different antimicrobials can be misleading. This can affect the decision to recommend one antibiotic over the other. We analyzed recalled data with the statistical consideration of unequal sample groups. Data was collected concerning children suspected to have typhoid fever at Al Alwyia Pediatric Teaching Hospital in Baghdad, Iraq. The study period extended from September 2021 to September 2022. A novel algorithm was developed to compare the drug sensitivity among unequal numbers of Salmonella typhi (S. Typhi) isolates tested with different antibacterials. According to the proposed algorithm, the predicted resistance values were more valid than the observed values. This proposed algorithm is expected to help the hospital antibiotic policy committee recommend the proper antibacterial agents for S. Typhi and further bacterial isolates

Topical vitamin A treatment of recalcitrant common warts

<p>Abstract</p> <p>Background</p> <p>Common warts (<it>verruca vulgaris</it>) are benign epithelial proliferations associated with human papillomavirus (HPV) infection. Salicylic acid and cryotherapy are the most frequent treatments for common warts, but can be painful and cause scarring, and have high failure and recrudescence rates. Topical vitamin A has been shown to be a successful treatment of common warts in prior informal studies.</p> <p>Case</p> <p>The subject is a healthy, physically-active 30 old female with a 9 year history of common warts on the back of the right hand. The warts resisted treatment with salicylic acid, apple cider vinegar and an over-the-counter blend of essential oils marketed for the treatment of warts. Daily topical application of natural vitamin A derived from fish liver oil (25,000 IU) led to replacement of all the warts with normal skin. Most of the smaller warts had been replaced by 70 days. A large wart on the middle knuckle required 6 months of vitamin A treatment to resolve completely.</p> <p>Conclusion</p> <p>Retinoids should be further investigated in controlled studies to determine their effectiveness in treating common warts and the broad range of other benign and cancerous lesions induced by HPVs.</p

Bingo: A Semi-Centralized Password Storage System

A lack of security best practices in modern password storage has led to a dramatic rise in the number of online data breaches, resulting in financial damages and lowered trust in online service providers. This work aims to explore the question of how leveraging decentralized storage paired with a centralized point of authentication may combat such attacks. A solution, “Bingo”, is presented, which implements browser side clients which store password shares for a centralized proxy server. Bingo is a fully formed system which allows for modern browsers to store and retrieve a dynamic number of anonymized password shares, which are used when authenticating users. Thus, Bingo is the first solution to prove that distributed password storage functions in the context of the modern web. Furthermore, Bingo is evaluated in both simulation and cloud in order to show that it achieves high rates of system liveness despite its dependence on its users being active at given intervals. In addition, a novel simulator is presented which allows future researchers to mock scheduled behavior of online users. This work concludes that with the rise in online activity, decentralization may play a role in increasing data security

Bingo: A Semi-Centralized Password Storage System

A lack of security best practices in modern password storage has led to a dramatic rise in the number of online data breaches, resulting in financial damages and lowered trust in online service providers. This work aims to explore the question of how leveraging decentralized storage paired with a centralized point of authentication may combat such attacks. A solution, &ldquo;Bingo&rdquo;, is presented, which implements browser side clients which store password shares for a centralized proxy server. Bingo is a fully formed system which allows for modern browsers to store and retrieve a dynamic number of anonymized password shares, which are used when authenticating users. Thus, Bingo is the first solution to prove that distributed password storage functions in the context of the modern web. Furthermore, Bingo is evaluated in both simulation and cloud in order to show that it achieves high rates of system liveness despite its dependence on its users being active at given intervals. In addition, a novel simulator is presented which allows future researchers to mock scheduled behavior of online users. This work concludes that with the rise in online activity, decentralization may play a role in increasing data security