186 research outputs found

    Short-term Traffic Flow Prediction Using Artificial Intelligence with Periodic Clustering and Elected Set

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    Forecasting short-term traffic flow using historical data is a difficult goal to achieve due to the randomness of the event. Due to the lack of a solid approach to short-term traffic prediction, the researchers are still working on novel approaches. This study aims to develop an algorithm that dynamically updates the training set of models in order to make more accurate predictions. For this purpose, an algorithm called Periodic Clustering and Prediction (PCP) has been developed for use in short-term traffic forecasting. In this study, PCP was used to improve Artificial Neural Networks (ANN) predictive performance by improving the training set of ANN to predict short-term traffic flow using selected clusters. A large amount of traffic data collected from the US and UK motorways was used to determine the PCP ability to increase the ANN performance. The robustness of the proposed approach was determined by the performance measures used in the literature and the mean prediction errors of PCP were significantly below other approaches. In addition, the studies showed that the percentage errors of PCP predictions decreased in response to increasing traffic flow values. Considering the obtained positive results, this method can be used in real-time traffic control systems and in different areas needed.</p

    Gençlik cinsel sağlığı: Türkiye'deki bir üniversitede öğrenciler arasında cinsel bilgi, tutumlar ve davranışlar]

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    Introduction: To determine sexual attitudes, behavior, and knowledge of Namik Kemal University (NKU) students about sexual health and sexually transmitted infections (STIs). Method: A sample representing 10% of the undergraduate population of NKU in 2009-2010, was studied. Of 1,500 questionnaires distributed, 1,314 (87.6%) were filled out. Results: The mean age of the respondents (52.9% male) was 20.07 +/- 1.75 years. The rate of students who had received sexual health education was 32.0%, and 15.3% had previously used a sexual health service. Eleven percent of the female students and 50.3% of the male students had had sexual intercourse. The average age of initial sexual intercourse was 16.83 +/- 2.07 years. Of the students who had had sexual intercourse, 46.6% reported that they did not use any contraception method. The most preferred method was condoms (37.6%). The rate of contraceptive use was 58.7% in sexually educated students and 43.9% in those not educated (p=0.004). The most well-known STI was AIDS (96.5%), with sexually educated students giving higher rates of correct answers about STIs (p<0.05) Conclusion: The students who had received sexual health education were more knowledgeable about vital consequences of STI's, even though it is not sufficient, than sexually active students. Awareness of safe sexual practices and changes in behavior, in particular, promoting condom use should be established in higher risk youths. Deficiencies in knowledge could be addressed by adding a sexual healthtraining component to the university curriculum, and unmet requirements could be met by reorganizing medico-social centers in universities

    An artificial intelligent approach to traffic accident estimation: Model development and application

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    This study proposes an Artificial Neural Network (ANN) model and a Genetic Algorithm (GA) model to estimate the number of accidents (A), fatalities (F) and injuries (I) in Ankara, Turkey, utilizing the data obtained between 1986 and 2005. For model development, the number of vehicles (N), fatalities, injuries, accidents and population (P) were selected as model parameters. In the ANN model, the sigmoid and linear functions were used as activation functions with the feed forward‐back propagation algorithm. In the GA approach, two forms of genetic algorithm models including a linear and an exponential form of mathematical expressions were developed. The results of the GA model showed that the exponential model form was suitable to estimate the number of accidents and fatalities while the linear form was the most appropriate for predicting the number of injuries. The best fit model with the lowest mean absolute errors (MAE) between the observed and estimated values is selected for future estimations. The comparison of the model results indicated that the performance of the ANN model was better than that of the GA model. To investigate the performance of the ANN model for future estimations, a fifteen year period from 2006 to 2020 with two possible scenarios was employed. In the first scenario, the annual average growth rates of population and the number of vehicles are assumed to be 2.0 % and 7.5%, respectively. In the second scenario, the average number of vehicles per capita is assumed to reach 0.60, which represents approximately two and a half‐fold increase in fifteen years. The results obtained from both scenarios reveal the suitability of the current methods for road safety applications. First published online: 27 Oct 201

    MADEN MAKİNELERİNİN FREKANS-GÜRÜLTÜ İLİŞKİSİ

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    Normal bir insan kulağı 20 Hz – 20000 Hz frekans aralığındaki sesleri duymakla birlikte farklı frekanstaki sesleri eş şiddetle algılamamaktadır. Bu nedenle gürültü düzeylerini belirlemenin yanında, gürültünün frekansı da dikkate alınmalıdır. Bu çalışmada Sivas ve komşu illerde yer alan toplam altı operasyonda kullanılan 67 adet iş makinesinden gürültü ölçümleri alınmış ve frekans-gürültü ilişkisi ortaya çıkarılmıştır. Buna göre paletli dozer ve lastik tekerlekli yükleyici operatörlerinin maruz kaldığı maksimum gürültü düzeyi büyük oranda düşük frekans aralığına, diğerleri orta frekans aralığına düşmektedir. Tüm iş makinesi operatörlerinin maruz kaldığı minimum gürültü düzeyleri yüksek frekans aralığındadır. Ölçüm yapılan iş makinelerinin maksimum gürültü düzeylerinin insan kulağının en hassas olduğu frekans aralığının dışında olduğu tespit edilmiştir. İş makinelerinin oluşturduğu gürültü geniş frekans aralığında yer almaktadır. Gürültü düzeyleri, zamanla değişim ölçütüne göre sınıflandırıldığında ölçüm alınan tüm iş makineleri kararsız gürültü sınıfına girmektedir

    Investigation of Factors Affecting Viral Clearance Time by Real-Time Polymerase Chain Reaction Method in Nasopharyngeal Swab Samples of COVID-19 Patients

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    The coronavirus disease-2019 (COVID-19) pandemic continues to threaten the lives of millions of people. Viral shedding through the respiratory tract is the main risk factor for the transmission of the severe acute respiratory syndrome-2 (SARS-CoV-2) virus from sick individuals to healthy individuals. In this study, we aimed to investigate the viral clearance (VC) time in PCR tests of COVID-19 patients and the possible factors affecting this time. Seventy patients older than 18 years of age whose presence of SARS-CoV-2 virus was proven by real-time polymerase chain reaction (Rt-PCR) in nasopharyngeal swab samples were included in the study. The presence of SARS-CoV-2 RNA was investigated by RT-PCR in nasopharyngeal swab samples at 48-72 hour intervals, five days after the initial diagnosis. Demographic, physical examination, laboratory test, computed tomography (CT) results, concomitant diseases, and duration of VC were recorded. Of the cases, 41 were female and 29 were male. The mean age was 45.8 +/- 19.2 years. According to the CT results, in the group with no involvement, local involvement and widespread involvement, the duration of VC was 9.66 +/- 5.91 days, 9.99 +/- 4.68 days, and 10.94 +/- 5.34 days, respectively (p>0.05). While the duration of VC was determined as 8.93 +/- 4.33 days in the group without comorbidity, this period was found to be 12.26 +/- 5.69 days (p=0.025) in the group with the comorbidity. It was determined that the duration of VC was 9.55 +/- 6.37 days in women and 9.20 +/- 7.22 days in men (p=0.040). The duration of VC was found to be 10.18 +/- 7.1 days in patients over 50 years of age and 8.87 +/- 5.15 days under 50 years of age (p=0.03). A significant correlation was found between the laboratory test lactate dehydrogenase level and VC duration (p=0.007). However, a significant relationship could not be established between other laboratory test results and the duration of VC. In this retrospective observational study, the relationship between viral clearance duration in Rt-PCR and gender, age, CT results, comorbidities and laboratory results in nasopharyngeal swab samples was investigated and it was determined that the duration of VC was significantly prolonged in case of female gender, being over 50 years old and having a comorbid disease. The results obtained may contribute to predict the isolation times of the patients and to reveal the factors that may affect viral shedding

    Factors leading to dissemination of cutaneous anthrax: an international ID-IRI study

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    Background: Although anthrax is a rare zoonotic infection, it still causes significant mortality and morbidity. In this multicenter study, which is the largest anthrax case series ever reported, we aimed to describe the factors leading to dissemination of cutaneous anthrax. Methods: Adult patients with cutaneous anthrax from 16 referral centers were pooled. The study had a retrospective design, and included patients treated between January 1, 1990 and December 1, 2019. Probable, and confirmed cases based upon CDC anthrax 2018 case definition were included in the study. A descriptive statistical analysis was performed for all variables. Results: A total of 141 cutaneous anthrax patients were included. Of these, 105 (74%) patients had probable and 36 (26%) had confirmed diagnosis. Anthrax meningitis and bacteremia occurred in three and six patients, respectively. Sequelae were observed in three patients: cicatricial ectropion followed by ocular anthrax (n = 2) and movement restriction on the left hand after surgical intervention (n = 1). One patient had gastrointestinal anthrax. The parameters related to poor outcome (p < 0.05) were fever, anorexia, hypoxia, malaise/fatigue, cellulitis, fasciitis, lymphadenopathy, leukocytosis, high CRP and creatinine levels, longer duration of antimicrobial therapy, and combined therapy. The last two were seemingly the consequences of dissemination rather than being the reasons. The fatality rate was 1.4%. Conclusions: Rapid identification of anthrax is crucial for prompt and effective treatment. Systemic symptoms, disseminated local infection, and high inflammatory markers should alert the treating physicians for the dissemination of the disease. © 2022 The Author

    Development of Cycle Length Models using Flower Pollination Algorithm for Isolated Signalized Intersections

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    Son zamanlarda nüfus ve ekonomideki büyüme karayollarında araç kullanımını arttırmakta, buna bağlı olarak da kavşakların kapasitesi yetersiz kalmaktadır. Kavşakların verimsiz çalışmasından dolayı gecikme, yakıt tüketimi, emisyon salınımı artarken sürücü davranışları da olumsuz etkilenmektedir. Kavşak geometrilerinin iyileştirilmesinin yanı sıra, optimum devre süresinin doğru tespiti ve sinyal sürelerinin düzenlenmesi ile de bu sorunların minimuma indirilebilmesi mümkün olmaktadır. Bu çalışmada Çiçek Tozlaşma Algoritması (ÇTA) kullanılarak optimum devre süresi modelleri geliştirilmiştir. Ayrıca en düşük gecikmeye sahip olan devre sürelerinin belirlenmesinde Diferansiyel Gelişim Algoritmasından (DGA) yararlanılmıştır. Kalibre edilen Webster modeline ilave olarak sabit eklenmiş Webster model formu ve üstel formda devre süresi modelleri geliştirilmiştir. VISSIM simülasyon programı ile elde edilen gecikme değerlerine göre geliştirilen bütün modeller Webster modeli ve VISTRO optimizasyon programı ile karşılaştırılmış ve önerilen modellerin istatistiksel olarak daha iyi performansa sahip olduğu görülmüştür. Bu modellerin özellikle yüksek trafik hacmine sahip trafik durumlarında yetersiz kalan Webster modelindeki eksiklikleri kapatarak alternatif bir devre süresi tahmin modeli olarak kullanılabileceği ön görülmektedir.Recently, the growth in population and economy has increased the use of vehicles on highways and accordingly the capacity of the intersections is insufficient. Delay, fuel consumption and emissions are increased due to the inefficient operation of intersections, and driver behavior is adversely affected. In addition to improving intersection geometry, by correct determination of optimum cycle length and arrangement of signal times, it is possible to minimize these problems. In this study, optimum cycle length models have been developed by using Flower Pollination Algorithm (FPA). Additionally, Differential Evolution Algorithm has been used to determine the cycle length which has the minimum delay value for each traffic situation. In addition to the calibrated Webster model, Webster model with constant form and exponential form have been developed as cycle length models. All models developed according to the delay values obtained with the VISSIM simulation program were compared with the Webster model and the VISTRO optimization program and the proposed models were found to have statistically better performance. It has been seen that these models can be used as an alternative cycle length estimation model by defeating the deficiencies in Webster model which is insufficient especially in traffic situations with high traffic volume

    Treatment of ventilator-associated pneumonia (VAP) caused by Acinetobacter: results of prospective and multicenter ID-IRI study

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    Ventilator-associated pneumonia (VAP) due to Acinetobacter spp. is one of the most common infections in the intensive care unit. Hence, we performed this prospective-observational multicenter study, and described the course and outcome of the disease. This study was performed in 24 centers between January 06, 2014, and December 02, 2016. The patients were evaluated at time of pneumonia diagnosis, when culture results were available, and at 72 h, at the 7th day, and finally at the 28th day of follow-up. Patients with coexistent infections were excluded and only those with a first VAP episode were enrolled. Logistic regression analysis was performed. A total of 177 patients were included; empiric antimicrobial therapy was appropriate (when the patient received at least one antibiotic that the infecting strain was ultimately shown to be susceptible) in only 69 (39%) patients. During the 28-day period, antibiotics were modified for side effects in 27 (15.2%) patients and renal dose adjustment was made in 38 (21.5%). Ultimately, 89 (50.3%) patients died. Predictors of mortality were creatinine level (OR, 1.84 (95% CI 1.279-2.657); p = 0.001), fever (OR, 0.663 (95% CI 0.454-0.967); p = 0.033), malignancy (OR, 7.095 (95% CI 2.142-23.500); p = 0.001), congestive heart failure (OR, 2.341 (95% CI 1.046-5.239); p = 0.038), appropriate empiric antimicrobial treatment (OR, 0.445 (95% CI 0.216-0.914); p = 0.027), and surgery in the last month (OR, 0.137 (95% CI 0.037-0.499); p = 0.003). Appropriate empiric antimicrobial treatment in VAP due to Acinetobacter spp. was associated with survival while renal injury and comorbid conditions increased mortality. Hence, early diagnosis and appropriate antibiotic therapy remain crucial to improve outcomes

    Self-reported antibiotic stewardship and infection control measures from 57 intensive care units: An international ID-IRI survey

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    Infection control; Multidrug resistance; StewardshipControl de infección; Resistencia a múltiples fármacos; AdministraciónControl d'infecció; Resistència a múltiples fàrmacs; AdministracióWe explored the self-reported antibiotic stewardship (AS), and infection prevention and control (IPC) activities in intensive care units (ICUs) of different income settings. A cross-sectional study was conducted using an online questionnaire to collect data about IPC and AS measures in participating ICUs. The study participants were Infectious Diseases–International Research Initiative (IDI-IR) members, committed as per their institutional agreement form. We analyzed responses from 57 ICUs in 24 countries (Lower-middle income (LMI), n = 13; Upper-middle income (UMI), n = 33; High-income (HI), n = 11). This represented (~5%) of centers represented in the ID-IRI. Surveillance programs were implemented in (76.9%−90.9%) of ICUs with fewer contact precaution measures in LMI ones (p = 0.02); (LMI:69.2%, UMI:97%, HI:100%). Participation in regional antimicrobial resistance programs was more significantly applied in HI (p = 0.02) (LMI:38.4%,UMI:81.8%,HI:72.2%). AS programs are implemented in 77.2% of institutions with AS champions in 66.7%. Infectious diseases physicians and microbiologists are members of many AS teams (59%&50%) respectively. Unqualified healthcare professionals(42.1%), and deficient incentives(28.1%) are the main barriers to implementing AS. We underscore the existing differences in IPC and AS programs’ implementation, team composition, and faced barriers. Continuous collaboration and sharing best practices on APM is needed. The role of regional and international organizations should be encouraged. Global support for capacity building of healthcare practitioners is warranted

    Listeria monocytogenes’in Etken Olduğu Bir Menenjit Olgusu

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    Listeriosis, Listeria monocytogenes’in (L. monocytogenes) neden olduğu toplumda nadir görülen bir enfeksiyon hastalığıdır. L. monocytogenes genellikle yüksek riskli hastaları, özellikle yaşlılar, bağışıklığı baskılanmış hastalar ve gebeleri enfekte eden bir bakteridir. Burada diabetes mellitus, pemfigus vulgaris hastalıkları olan 79 yaşında erkek hastada L. monocytogenes’e bağlı menenjit gelişen bir olgu sunulmaktadır
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