18 research outputs found
Electronically tunable MOSFET-only current-mode biquad filter
A novel current mode MOSFET-only structure with multi-input single-output (MISO) is proposed. The proposed circuit is free from passive circuit elements like resistors and capacitors and able to realize low-pass (LP), band-pass (BP), high-pass (HP), band-stop (BS) and all-pass (AP) filter functions with using the same circuit configuration. It is also important to note that the proposed filter has electronic tunability property. The proposed circuit is laid-out in the Cadence environment using 0.18 mu m TSMC CMOS technology parameters. The layout area is only 408 mu m(2) and the power consumption is about 0.6 mW. Furthermore, to investigate the performance of the BP filter output of the proposed MISO filter, Monte Carlo and corner analyses are also presented. It is shown that the mismatches and the process variations cause only small deviations for the BP filter configuration. Furthermore, the noise performance of the proposed filter is also investigated. (C) 2017 Elsevier GmbH. All rights reserved
MOSFET-Only filter design automation based on polynomial regression with exemplary circuits
In this work, a novel design automation method is presented for easy construction of MOSFET-Only or MOSFET-C filters. In contrast to previous works in the literature, the proposed algorithm is simple since it uses polynomial fitting models obtained from SPICE data in order to reformulate small signal parameters and some DC characteristics of MOSFET's. Polynomial regressive models facilitate to interact between design constraints (power, area, speed, pole frequency etc.) and design variables (operating voltages, currents and device dimensions). In this regard, two novel agile MOSFET-Only filters produced with the proposed automation process are presented in order to qualify the automation flow. The produced filters are simulated in LT-SPICE and CADENCE-SPECTRE environment by using 0.18 mu m TSMC technology. These agile filters can easily be used in a wide range of applications such as encrypted communications or very high frequency circuits. In addition, it is shown that there is a good agreement between proposed design automation flow and simulations
A novel low power MOSFET-C band pass filter for low frequency applications with subthreshold models based on polynomial regression
A novel current mode MOSFET-C filter is presented for a wide range of low frequency applications ranging from biomedical signal sensing up to speech processing region. Presented filter consumes only 2.3 mu W with symmetrical supply voltages as low as +/- 0.5 V. The filter structure can be easily adjusted by means of changing external capacitor values. Furthermore, proposed filter is given with a novel design methodology based on polynomial regressive small signal models. In this way, promising interaction between design parameters such as V-GS, V-DS, channel width (W), channel length (L) and filter specifications such as f(0), Q and power is provided. Simulation results with 0.18 mu m TSMC CMOS technology are given, furthermore proposed filter is tested to process a real fetal PCG signal at 355.4 Hz. It is shown that proposed filter attains a promising performance in comparison with the previously presented counterparts for low frequency applications
Current mode single-input multi-output MOSFET-only filter
In this paper, a very simple topology of a current mode MOSFET-only filter with single-input and multi output is proposed. It is very important to emphasize that it is possible to obtain five of the filter functions, namely low-pass (LP), band-pass (BP), high-pass (HP), band-stop (BS) and all-pass (AP) using the proposed topology without using external passive elements. The core circuit of the proposed filter employs only four MOS transistors; therefore, it occupies very small chip area. It is also possible to adjust the filter gain with the biasing voltage. In addition, the circuit exhibits a very low input impedance and also high output impedances which make it possible for cascading. The MOSFET capacitances which determine the transfer functions are all grounded, so physical capacitances can be used instead of MOSFET parasitic capacitances to operate the filter at very low frequencies. Moreover, proposed filter structure has low supply voltage as 1 V in order to be applicable to low voltage operations. Detailed simulation results, including noise and Monte Carlo analysis, are provided using 0.18 pm TSMC technology parameters to verify the feasibility of the filter circuit. (C) 2017 Elsevier GmbH. All rights reserved
Novel First Order Current Mode MOS-C Phase Shifters
In this work, novel first order MOS-C phase shifter structures are proposed in NMOS and PMOS configurations. Core circuits consist of only three transistors and a single capacitor. The pole frequency of the phase shifters can be easily controlled by the bias voltage. The presented circuits in this work bring advantages such as low power consumption and small chip area when compared to other works including large numbers of active and passive elements in the literature. Furthermore, the proposed circuits are designed with a simple design automation flow that is proper for MOS-Only or MOS-C architectures. It is shown by simulations that the simulation results agree with the theoretical results for a wide frequency range
Performance analysis of Dirac video codec in different motion vector accuracies and wavelet lifting decompositions
Özenli, Deniz (Dogus Author) -- 2011 proceedings / ELMAR: Zadar, Croatia, 14 - 16 September 2011Dirac is presented by BBC to compress video streams efficiently and eliminate software payments for license fees. Dirac video codec structure allows new wavelet tools to be specified by a user in order to improve its performance. In this paper, Dirac performance is analyzed for different motion vector accuracies and with different wavelet tools. Meanwhile, a new decomposition filter scheme is proposed for Dirac to compensate computational complexity that arises due to subpixel precision analyses and filter structures of this codec. Investigated codec has a stable structure therefore correct interpretations are possible for different test sequences using the comparison tables in this paper.Tankerska plovidba, Transmitters and Communications (OiV), Croatian Radio and Television (HRT
Prevalence and associated riskfactors of somatization disorder among Turkish university students at an education faculty [Türkiye'de bir egitim fakültesinde somatjzasyon bozuklugu yayginligi ve ilişkili risk etkenlerinin araştirilmasi]
Objective: There are no studies in the literature investigating the epidemiology of somatization disorder at a large sample group of young adults. Therefore, the present study aimed to determine the lifelong prevalence and possible associated risk factors of somatization disorder among students of Çukurova University Education Faculty. Methods: The study group included 804 students. We first applied a semi-constructed questionnaire of socio-demographic characteristics and General Health Questionnaire-12 (GHQ-12) and then administered the Composite International Diagnostic Interview (CIDI) part C for the psychiatric diagnosis. Logistic regression analysis was performed in order to evaluate the possible risk factors associated with somatization disorder. Results: Somatization disorder was diagnosed in 62 people (7.7%). Female sex, history of chronic illness, lower educational level of mother and verbal abuse in the family were found to be statistically significant risk factors related with somatization disorder. Conclusion: This study demonstrate a higher prevalence of somatization disorder among a group of university students compared to other prevalence studies of somatization disorder in the general population. Also according to our results there might be some important risk factors for young adults of our country associated with somatization disorder
Blood lipid levels of suicidal patients [İntihar girişiminde bulunan hastalarda kan lipid seviyeleri]
Objective: Clinical interview is the most important step in determining the suicide intent. Besides, psychometric tests are also important. However, the standard measurement or psychometric tests are still unsatisfactory on this subject. This is why investigations on biological parameters have been increased for determining the risk of suicide in recent years. In this study, the aim was to investigate the blood lipid levels in depending on life event and not life event suicide attempted two groups and to compare them with controls. Material and Methods: Our groups consisted of 56 patients who experienced a pre-suicidal life event, 31 patients who did not experience a pre-suicidal life event and 32 healthy volunteers as the control group. The Beck Depression Inventory (BDI) and Problem Solving Inventory (PSI) for measuring problem solving skills were used in this study. Results: Blood cholesterol levels were 153.23±9.31 mg/dL in suicidal group that experienced a life event, 131.90±6.85 in the group that did not experience a life event, and 184.40±17.18 in the control group. There was a significant difference among the groups in variance analysis (p<0.001). Triglyceride levels of the groups were 67.25±16.17, 72.80±14.76 and 111.68±12.60 mg/dL, respectively. There were significant differences among three groups for triglyceride levels (p<0.001). In addition, there was no statistically significant difference between suicidal groups and the control group for BDI or PSI tests. Conclusion: One must be more careful for diagnosis and treatment of patients with a high suicidal risk, and this especially applies for primary care physicians. It is clear that monitoring these risky cases with surveys and routine tests such as blood lipids is useful. © 2014 by Türkiye Klinikleri
Prevalence and associated risk factors of somatization disorder among Turkish university students at an education faculty
Amaç: Literatüre bakıldığında, somatizasyon bozukluğunu üniversite öğrencilerinde araştıran, geniş örneklem grubuyla yürütülmüş epidemiyolojik bir çalışmaya rastlanmamıştır. Bu nedenle bu çalışmada, Çukurova Üniversi-tesi Eğitim Fakültesi öğrencileri arasında somatizasyon bozukluğunun yaşam boyu yaygınlığı ve ilişkili risk etkenlerinin araştırılması amaçlanmıştır. Yöntem: Araştırmaya 804 öğrenci alınmıştır. Öncelikle sosyodemografik özellikler için yarı yapılandırılmış bir anket ve Genel Sağlık Anketi-12 (GSA-12), sonrasında ise psikiyatrik tanı için Uluslararası Bileşik Tanı Görüşmesi’nin (CIDI) C bölümü uygulanmıştır. Somatizasyon bozukluğuyla ilişkili olası risk etkenlerini belirlemek amacıyla lojistik regresyon analizi uygulanmıştır. Bulgular: Çalışmaya katılan öğrenci-lerin 62’sine (%7.7) somatizasyon bozukluğu tanısı konmuştur. Kadın cinsiyet, kronik hastalık öyküsü, annenin düşük öğrenim durumu ve aile içerisinde sözlü taciz ile somatizasyon bozukluğu arasında istatistiksel olarak anlamlı düzeyde ilişki bulunmuştur. Sonuç: Üniversite öğrencilerinde gerçekleştirilen bu çalışmada somatizasyon bozukluğu yaygınlığı genel popülasyonda yapılmış epidemiyolojik araştırmalara kıyasla daha yüksek bulunmuş-tur. Ayrıca elde edilen bulgular, ülkemizde, genç-yetişkinlerde somatizasyon bozukluğunun gelişimiyle ilgili önemli bazı risk etmenlerinin varlığına işaret etmektedir.Objective: There are no studies in the literature investigating the epidemiology of somatization disorder at a large sample group of young adults. Therefore, the present study aimed to determine the lifelong prevalence and possible associated risk factors of somatization disorder among students of Çukurova University Education Faculty. Methods: The study group included 804 students. We first applied a semi-constructed questionnaire of socio-demographic characteristics and General Health Questionnaire-12 (GHQ-12) and then administered the Composite International Diagnostic Interview (CIDI) part C for the psychiatric diagnosis. Logistic regression analysis was performed in order to evaluate the possible risk factors associated with somatization disorder. Results: Somatization disorder was diagnosed in 62 people (7.7%). Female sex, history of chronic illness, lower educational level of mother and verbal abuse in the family were found to be statistically significant risk factors related with somatization disorder. Conclusion: This study demonstrate a higher prevalence of somatization disorder among a group of university students compared to other prevalence studies of somatization disorder in the general population. Also according to our results there might be some important risk factors for young adults of our country associated with somatization disorder
Prevalence of eating disorders in female university students and affecting factors [Kadın üniversite öğrencilerinde yeme bozukluğunun yaygınlığı ve etkileyen etkenler]
Objective: The purpose of this study is to determine the size and the prevalence of eating disorders among the female students at the University of Çukurova and to evaluate the affecting sociodemographic and psychological factors. Methods: This cross-sectional was carried out among female students who study at Cukurova University between November 2012 and May 2013. While 668 students were planned to achieve, 32 (4.7%) of the students were absent, thus a total 636 students (95.3%) were included in the study. A questionnaire that queries socio-demographic characteristics, Eating Attitudes Test (EAT), the Beck Depression Inventory (BDI) and the Liebowitz Social Anxiety Scale (LSAS) were administered to the participants by face to face interview method. After the ques-tionnaires completed, weight and height were measured to calculate the body mass index (BMI). In data evaluation, for comparisons of numerical variables t-test between independent groups; for comparisons of categorical variables chi-square test was used. Findings: The mean age of the participants was 21.63±1.80. According to the EAT cut-off scores 6.3% of the participants were found to have an eating disorder. Eating disorders were found to be signi-ficantly low in those who have crowded families. Preexisting disease existence, BMI and BDI scores of eating disor-ders were significantly higher than those without eating disorders. LSAS scores were not significantly different between students with or without eating disorders. Conclusion: Eating disorders are common in university stu-dents. It should be also kept in mind that students who have depressive symptoms and high BMI are at risk in terms of eating disorders. © 2016, Cukurova University, Faculty of Medicine. All rights reserved