1,645 research outputs found
New CMOS Realization of Voltage Differencing Buffered Amplifier and Its Biquad Filter Applications
In this paper, new biquad filter configuration using a recently introduced active element, namely Voltage Differencing Buffered Amplifier (VDBA), is proposed. This block has high impedance input terminals and low impedance output terminal, providing advantages at voltage mode circuits. Besides, VDBA has a transconductance gain, thus the proposed circuits can be employed without using any external resistors. Two new voltage-mode biquad filter configurations are presented for VDBA application. Each proposed filter employs two active elements and two or three passive components. Filters, having three inputs and single output, can realize voltage-mode low-pass, band-pass, high-pass, band-stop, and all-pass filters. The biquad filters have low output impedances that is necessity for cascadability for voltage mode circuits, and no critical component matching conditions are required. For the second biquad, quality factor can be adjusted via resistor independently of the natural frequency. Simulation results are given to, confirming the theoretical analysis. The proposed biquad filters are simulated using TSMC CMOS 0.35 µm technology. LTSPICE simulations of the proposed circuits give results that agree well with the theoretical analysis
Automatic skin cancer detection system
University of Technology Sydney. Faculty of Engineering and Information Technology.During recent decades, the incident of malignant melanoma as the lethal form of skin cancer has been raised. The occurrence in Australia is much higher than US, UK, and Canada with the cases more than 10,000 diagnosis and annual mortality of 1250 people. The persistent raise of this cancer in the worldwide, the high medical cost and death rate have prioritized the early diagnosis of this cancer. The anticipation and cure of melanoma is strictly relevant to its thickness, if it can be detected early, the survival rate would be increased. Although lots of effort has been made to advance the detection of skin cancers, the challenging concerns still about it.
The computer-based detection systems can improve the diagnosis rate of melanoma by 5–30% in comparison with the naked-eye. Since the visual perception often involve some faults, the necessity of second opinion with higher accuracy and reliability is highlighted. On the other hand, it reduces the task and responsibilities that are performed by physicians.
Many researches have been developed in automated detection of melanoma. The potential advantages of such studies are significant and incalculable. Moreover, the difficulties entangle are a lot, and the new contributions in the area are highly appreciated. However, it is extensively acknowledged that the more trustful and reliable detection systems require higher accuracy. The purpose of this thesis is to propose an algorithm for skin cancer diagnosis that is able to classify lesions as malignant or benign automatically.
The different components in an automated diagnosis of skin cancer includes: Pre-processing, segmentation, feature extraction and selection, and classification. In this thesis, after selecting the best image enhancement techniques which are achieved by applying and comparing different noise removal and contrast enhancement techniques on images, the segmentation stage is performed. In this stage, a fully automated segmentation algorithm in dermoscopy images based on k-mean and level-set algorithms are proposed and compared with other algorithms mentioned in this thesis using statistical tools. Proposed algorithm shows the improvement in the results.
In the next stage, after extracting the various features of images, a fully automated feature selection algorithm, Smart PSO-SVM, which optimizes the feature selection stage, is proposed. Comparative study of proposed algorithm with other algorithms is performed to analyse the performance of proposed algorithm among others. The results obtained in the best subset of features which feed the classification stage. In classification stage, the use of SA-SVM as a new classifier in the area of skin cancer detection systems is proposed. The average accuracy and F-score are estimated as 87.0611% and 0.9167 respectively. The statistical evaluation using t-test also shows the superiority of proposed algorithm when compares with other algorithms in this thesis
استفاده از فناوری تلفن همراه در بهبود کیفیت آموزش دانشجویان پرستاری
با
توجه به اینکه اکثریت دانشجویان از گوشی های هوشمند تلفن
همراه و دیگر وسایل همراه، استفاده می کنند، پیشنهاد می شود
نرم افزارهایی برای فعالیتهای آموزشی در زمینه پرستاری در
ایران طراحی گردد و به روشی منسجم طبقه بندی و ارزیابی
شده در اختیار دانشجویان پرستاری قرار گیرد. انجام تحقیقاتی
در این زمینه به تعیین اثربخشی یادگیری از طریق موبایل
و افزایش کیفیت آموزش با این روش
کمک کننده خواهد بو
Photoswitchable Self-Complementary Hydrogen Bond Arrays
Background: Photochromism is the reversible transformation of a chemical material to another form by the absorption of electromagnetic radiation (light), where the two metastable forms have distinct absorption spectra and other properties. Photochromism in materials allows for the switching of their function solely based on irradiation with light. Polymers are used frequently as the building blocks for materials as they are versatile, multifunctional, can carry charge and be processed by solution-based deposition methods. Supramolecular polymers share the same definition as polymers with the exception that they are held together by reversible and directional non-covalent interactions such as hydrogen bonds. Synthesizing supramolecular polymers with hydrogen bonds can be carried out in two possible arrangements. Hydrogen bonds can form between different (complementary) or the same monomeric end groups (self-complementary). This poster presentation will focus on our recent efforts toward the investigation of the strength and fatigue-resistance of the hydrogen bonding interaction between self-complementary hydrogen bond arrays intended for elaboration in supramolecular polymeric materials. The supramolecular and photophysical properties will be examined using UV-Vis Spectroscopy, Nuclear Magnetic Resonance, and dilution experiments. Future steps include incorporating these photochromic compounds into functional polymers to evaluate the photocontrolled elasticity, molecular alignment and self-healing abilities of the resulting materials
Investigation of the Zinc Oxide Nanoparticles Effect on Thyroid and Testosterone Hormones in Male Rats
Exposure to zinc oxide nanoparticles (ZnO NPs) has been increasing steadily, causing more attention being paid to their potential toxicity, including cytotoxicity and genotoxicity. Hence, this study aimed to investigate the effect of ZnO NPs on thyroid hormone triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone (TSH) as well as testosterone hormone in male adult rats. A total of 54 Sprague-Dawley albino adult male rats were divided into nine groups each of six rats, daily treated intraperitoneal with ZnO NPs two different doses (30 and 60) mg/kg in three different periods of time (7, 14, and 28) days, as following: Control groups (Groups 1, 2, and 3): Respectively received intraperitoneal injection with distilled water for 7, 14, and 28 days, experimental groups (Groups 4, 5, and 6): They were rats, respectively, received intraperitoneal dose (60 mg/kg) of ZnO NPs for (7, 14, and 28) days, and group (7, 8, and 9) experimental groups were rats, respectively, received intraperitoneal dose (30 mg/kg) of ZnO NPs for (7, 14, and 28) days. Data showed high significant decrease (P < 0.01) in level of T3, T4, TSH, and level of testosterone also decrease at high and low dose for 7, 14, and 28 days
بررسی میزان انواع خشونت خانگی و عوامل مرتبط با آن در مادران باردار منطقه کلاله
یافتهها: 312 نفر معادل 78 درصد از مادران باردار به اشکال مختلف مورد خشونت قرار گرفته بودند. شایعترین نوع خشونت علیه مادران باردار، عاطفی بود و 78 نفر از زنان از خشونت جسمی و 53 نفر از خشونت جنسی شکایت داشتند. همچنین با افزایش تحصیلات خشونت علیه مادران کاهش پیدا کرد. بین خشونت خانگی و مصرف سیگار و عدم اشتغال همسر رابطه معناداری مشاهده شد
Introduction: Violence against women is a universal phenomenon which has negative impact on the mental health of the family and society, and the consequences such as increased health care costs, reduced productivity and labor force of women are another results of this health and social cultural problem. So, this study was performed with aim to determine types of domestic violence and its related factors in pregnant women.
Methods: This descriptive-analytic study was performed on 368 pregnant mothers in area of Kalaleh in 2014. Data were collected by simple sampling and using a questionnaire. Data was analyzed with SPSS software (version 19) and descriptive statistics and Fisher's exact test, Chi-square, independent t-test, and Pearson correlation test.
Results: 312 pregnant women (84.78%) had been exposed to different types of violence. The most common type of violence against pregnant women was emotional with 181 cases (49.18%) and 78 (21.20%) complained of physical violence and 53 (14.40%) of sexual violence. Increased education reduced violence against women. There was a significant relationship between domestic violence, smoking and lack of husband's employment (P <0.05).
Conclusion: According to high rate of domestic violence, it is recommended to screen violence in the all health and therapy centers. Also, life skills training and counseling culture among couples is important
An Empirical Ultra Wideband Channel Model for Indoor Laboratory Environments
Channel measurement and modeling is an important issue when designing ultra wideband (UWB) communication systems. In this paper, the results of some UWB time-domain propagation measurements performed in modern laboratory (Lab) environments are presented. The Labs are equipped with many electronic and measurement devices which make them different from other indoor locations like office and residential environments. The measurements have been performed for both line of sight (LOS) and non-LOS (NLOS) scenarios. The measurement results are used to investigate large-scale channel characteristics and temporal dispersion parameters. The clustering Saleh- Valenzuela (S-V) channel impulse response (CIR) parameters are investigated based on the measurement data. The small-scale amplitude fading statistics are also studied in the environment. Then, an empirical model is presented for UWB signal transmission in the Lab environment based on the obtained results
Vibroscape analysis reveals acoustic niche overlap and plastic alteration of vibratory courtship signals in ground-dwelling wolf spiders
To expand the scope of soundscape ecology to encompass substrate-borne vibrations (i.e. vibroscapes), we analyzed the vibroscape of a deciduous forest floor using contact microphone arrays followed by automated processing of large audio datasets. We then focused on vibratory signaling of ground-dwelling Schizocosa wolf spiders to test for (i) acoustic niche partitioning and (ii) plastic behavioral responses that might reduce the risk of signal interference from substrate-borne noise and conspecific/heterospecific signaling. Two closely related species - S. stridulans and S. uetzi - showed high acoustic niche overlap across space, time, and dominant frequency. Both species show plastic behavioral responses - S. uetzi males shorten their courtship in higher abundance of substrate-borne noise, S. stridulans males increased the duration of their vibratory courtship signals in a higher abundance of conspecific signals, and S. stridulans males decreased vibratory signal complexity in a higher abundance of S. uetzi signals
EFFECTS OF SILVER NANOPARTICLES ON THYROID GLAND STRUCTURE AND FUNCTION IN FEMALE RATS
Objective: Due to their unique properties, silver nanoparticles (AgNPs) gained a broad utilization in nano-based industries and medicine, which may expose human to increased levels of NPs. However, little is known about their potential harmful effects on endocrine physiology. Hence, this study aimed to investigate the potential dose- and time-dependent outcomes of AgNPs on serum levels of thyroid hormones and thyroid gland histology in female rats.Methods: A total of 60 female rats were divided into three groups (each of 20 animals), treated with AgNPs for (10, 20, and 30) days. Within each treatment period, animals were assigned into four subgroups each of five rats; control treated with vehicle and the others treated with 12.5, 25, and 50 mg/kg of AgNPs, respectively, by intraperitoneal injection. At the end of treatments, all rats were sacrificed; blood samples were obtained and analyzed for serum levels of T3, T4, and thyroid-stimulating hormone (TSH). Thyroid gland was removed and weighed then kept in buffered formalin solution for microscopic examination.Results: The data showed a significant increase in the weight of the thyroid gland after 20 and 30 days of the treatment with 50 mg/kg of AgNPs, while the 25 mg/kg dose of AgNps resulted in significant increase only after 30 days. Serum levels of T3 and TSH were nonsignificantly altered by AgNPs in all the treatment groups. Thyroxin levels (T4) were significantly decreased after long-term exposure. Histological specimens of AgNPs treated group showed disturbance of the normal architecture of the thyroid tissue with degeneration of thyroid follicles and desquamated luminal cells.Conclusion: The results of the current study suggested the possible disrupting potential of long-term exposure to high level of AgNPs on thyroid gland function and histology in female rats
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