Variant-oriented Planning Models for Parts/Products Grouping, Sequencing and Operations

This research aims at developing novel methods for utilizing the commonality between part/product variants to make modern manufacturing systems more flexible, adaptable, and agile for dealing with less volume per variant and minimizing total changes in the setup between variants. Four models are developed for use in four important domains of manufacturing systems: production sequencing, product family formation, production flow, and products operations sequences retrieval. In all these domains, capitalizing on commonality between the part/product variants has a pivotal role. For production sequencing; a new policy based on setup similarity between product variants is proposed and its results are compared with a developed mathematical model in a permutation flow shop. The results show the proposed algorithm is capable of finding solutions in less than 0.02 seconds with an average error of 1.2%. For product family formation; a novel operation flow based similarity coefficient is developed for variants having networked structures and integrated with two other similarity coefficients, operation and volume similarity, to provide a more comprehensive similarity coefficient. Grouping variants based on the proposed integrated similarity coefficient improves changeover time and utilization of the system. A sequencing method, as a secondary application of this approach, is also developed. For production flow; a new mixed integer programing (MIP) model is developed to assign operations of a family of product variants to candidate machines and also to select the best place for each machine among the candidate locations. The final sequence of performing operations for each variant having networked structures is also determined. The objective is to minimize the total backtracking distance leading to an improvement in total throughput of the system (7.79% in the case study of three engine blocks). For operations sequences retrieval; two mathematical models and an algorithm are developed to construct a master operation sequence from the information of the existing variants belonging to a family of parts/products. This master operation sequence is used to develop the operation sequences for new variants which are sufficiently similar to existing variants. Using the proposed algorithm decreases time of developing the operations sequences of new variants to the seconds

The Prevalence of Allergy symptoms in Students in Rural Area

Background: Asthma, allergic rhinitis and eczema as a common disorder in childhood, has many epidemiologic variations in different geographic areas. This study aimed at determining the prevalence of pediatric allergic disease in rural area of Babol. Methods: This analytical-cross sectional study was performed in 2012 by random sampling on 2 groups of children; the first group aged 6-7 years (n=1735) and the second group aged 12-14 years (n=2080) during 2012. Data was collected by ISAAC first phase questionnaire and analyzed by SPSS 17 and Chi square test. Results: The prevalence of asthma in elementary school was 19% and in guidance school was 29.9% (p=0.000). The prevalence of allergic rhinitis in primary school in guidance school was 9.9% and 18.1%, respectively (p=0.000). There was no significant difference (p=0.223) between Elementary school (6.1%) and Guidance school (5.5%) in terms of prevalence of eczema. Conclusions: The results showed that the prevalence of asthma and allergic rhinitis in the rural area of Babol was remarkable that was high in older age group and needs to more attention in health program for decreasing this prevalence

Popularity and Harms of Aural Foreign Bodies: A Descriptive Study of Patients in Baqiyatallah University Hospital, Tehran, Iran.

peer reviewed[en] OBJECTIVE: To evaluate the prevalence of external ear complications among Iranian aural foreign body users attending to otolaryngology clinic of our hospital. METHODS: In this cross-sectional study patients attending to Otolaryngology clinics of Baqiyatallah hospital were enrolled regardless of their age, gender and reason of attending. Patients between 15 and 60 years of age were included in the present study. Those with positive history of chronic ear diseases, ear surgery, congenital ear disorders, trauma to ear or head and neck region or shock wave trauma were excluded from the study. Demographic information as well as data on chief complaint, educational level, frequency and type of used foreign body and findings of physical examination and Otoscopy by a single otolaryngologist were recorded in a predesigned checklist. RESULTS: Eventually 362 patients (232 male and 130 female) with a mean age of 40.32 ± 16.90 years underwent analysis. Of all patients 244 (67.2%) were using a kind of aural foreign body frequently and Cotton bud was the most popular (63.5%) used foreign body among patients. Drying ear canal was the most common (54.9%) reason of using AFBs among study individuals followed by itching (29.5%) and pyorrhea (11.06%). Also 11 (4.5%) patients were using AFBs as a habit with no specific reason. Itching was the most prevalent symptom reported by both aural foreign body users (78%) and non-users (45.5%); however it was significantly higher among AFB users (p = 0.026). Also hearing loss was significantly more reported by AFB users (p = 0.033). A majority of patients had normal physical examination in both AFB users and non-users group. Inflammation of ear canal was significantly more detected in AFB users (p = 0.004). In addition, rate of right ear wax impaction was higher among AFB users (p = 0.016). CONCLUSION: In conclusion we realized that 67.2% of patients attending to Otolaryngology clinic of our hospital were using a kind of aural foreign bodies and itching was the most common chief complaint of these patients

Prevalence, awareness, treatment, and control of hypertension based on ACC/AHA versus JNC7 guidelines in the PERSIAN cohort study

In this cross-sectional population-based study, we used the baseline data of the Prospective Epidemiologic Research Studies in IrAN cohort study collected in Iran from 2014 to 2020. The main outcomes were the prevalence of hypertension and proportion of awareness, treatment, and control based on the 2017 ACC/AHA guideline compared to the seventh report of the Joint National Committee (JNC7). Of the total of 163,770 participants, aged 35–70 years, 55.2% were female. The sex-age standardized prevalence of hypertension was 22.3% (95% CI 20.6, 24.1) based on the JNC7 guideline and 36.5% (31.1, 41.8) based on the ACC/AHA guideline. A total of 24,312 participants [14.1% (10.1, 18.1)] were newly diagnosed based on the ACC/AHA guideline. Compared to adults diagnosed with hypertension based on the JNC7 guideline, the newly diagnosed participants were mainly young literate males who had low levels of risk factors and were free from conventional comorbidities of hypertension. About 30.7% (25.9, 35.4) of them (4.3% of the entire population) were eligible for pharmacologic intervention based on the ACC/AHA guideline. Implementation of the new guideline may impose additional burden on health systems. However, early detection and management of elevated blood pressure may reduce the ultimate burden of hypertension in Iran

The prevalence of Eczema in Iranian children: A systematic review and Meta-Analysis

Eczema is a very common disorder that affects children. To find out the national prevalence of eczema in Iranian children, we conducted a systematic review and meta-analysis by using the Google Scholar, PubMed in Medline area, AltaVista, IranMedex and Magiran in August 2013. The search terms included: Prevalence, Eczema, Children, Pediatric, Allergy, ISAAC and Iran. From 156 related articles based on criteria, all the studies performed on children by the International Study of Asthma and Allergies in Childhood protocol that contained eczema manifestations were selected. The required informations from each study included the authors name, date, city, size of population, prevalence of eczema and number of children in elementary school age groups (6-7 years) and junior high school (13-14 years). The information was recorded in designed tables. The extracted data were analyzed by STATA 11. In this study, we analyzed 16 studies including 56,424 children in whom 28, 113 were in 6-7 years age group and 28, 311 in 13-14 years age group. The pooled prevalence of eczema in children aged 6-7 years and 13-14 years was 5.98% and 6.52%, respectively. This review revealed the prevalence of eczema in Iranian children. This information can be helpful to identify and control eczema symptoms in children suffering from allergic disorders

The prevalence of Eczema in Iranian children: A systematic review and Meta-Analysis

Eczema is a very common disorder that affects children. To find out the national prevalence of eczema in Iranian children, we conducted a systematic review and meta-analysis. We conducted a literature review by using the Google Scholar, PubMed in Medline area, AltaVista, IranMedex and Magiran in August 2013. The search terms included: Prevalence, Eczema, Children, Pediatric, Allergy, ISAAC and Iran. From 156 related articles based on criteria, all the studies performed on children by the International Study of Asthma and Allergies in Childhood protocol that contained eczema manifestations were selected. The required informations from each study included the authors name, date, city, size of population, prevalence of eczema and number of children in elementary school age groups (6-7 years) and junior high school (13-14 years). The information was recorded in designed tables. The extracted data were analyzed by STATA 11. In this study, we analyzed 16 studies including 56,424 children in whom 28,113 were in 6-7 years age group and 28,311 in 13-14 years age group. The pooled prevalence of eczema in children aged 6-7 years and 13-14 years was 5.98% and 6.52%, respectively. This review revealed the prevalence of eczema in Iranian children. This information can be helpful to identify and control eczema symptoms in children suffering from allergic disorders

Clinical Features and Paraclinical Findings of Patients Died of COVID-19 in a Referral Hospital in Sari, Iran, February 2020-May 2020

Background and purpose: The Coronavirus Disease 2019 (COVID-19) was first observed in December 2019 and caused a global pandemic. The aim of this study was to evaluate the clinical features and paraclinical findings in patients who died of COVID-19 in Sari Imam Khomeini Hospital, February 2020- May 2020. Materials and methods: A cross-sectional descriptive and retrospective study was done by reviewing the medical records of 149 patients who died of Covid-19 whose diagnosis was confirmed by chest CT scan or PCR-RT. Independent sample t test was used to compare quantitative variables and Chi-square test was used for analyzing qualitative variables. Results: The mean age of death from Covid-19 was 63.36±15.26 years and 58.1% were male. The most common clinical complaints were cough, fever, and dyspnea. The most common manifestation of chest CT scan was bilateral involvement. Among the dead cases of COVID-19, 13.5% had myocarditis and 4.7% developed respiratory complications (such as pneumothorax). According to findings, 54.1% died of cardiac arrest and 44.6% died due to respiratory arrest. Conclusion: Many ambiguities of SARS-CoV-2 still remain that require extensive studies and research in various aspects. Evaluation of demographic, radiological, clinical complications, and laboratory features can help physicians in finding ways to reduce mortality, perform more effective treatments, and use predictive tools

The Prevalence of Asthma, Allergic Rhinitis and Eczema in North of Iran: the International Study of Asthma and Allergies in Childhood (ISAAC)

Objective: Asthma, allergic rhinitis and eczema as a common chronic disorder in childhood, has many epidemiologic variations in different geographic areas. Uniform and standard epidemiologic researches are able to clear and modify scientific questions in this field. We carried out this study to determine the prevalence and intensity of pediatric allergic disease in our region. Material & Methods: This analytical-cross sectional study was performed on 2 groups of children; the first group aged 6-7 years (n=3240) and the second group aged 12-14 years (n=3254) during 2002-03. According to ISAAC programming, sample size consisted of 3000 children in each group. From all students 99.3% of primary students and 88.8% of guidance students entered into study. Data was gathered by ISAAC first phase questionnaire and analyzed by SPSS 10 and Chi square test. Findings: The 12-month prevalence rates of symptoms were as follow: wheezing 16.8% and 21.7%, allergic rhinitis symptoms 14.5% and 19.9% and atopic dermatitis symptoms 4.5% and 8.2%, for younger and older age group, respectively. The prevalence of wheezing and current wheeze did not show differences according to sex (P>0.05) but it was significantly higher in students of guidance school (P<0.05). The prevalence of previous history of asthma, speech disorders, wheezing after physical exercises and dry cough at night, rhinoconjuntivitis, recurrent rhinitis, eczema with pruritus, recurrent lesions and history of eczema was significantly higher in boys and in students of guidance school (P<0.05). The prevalence of flexor lesion did not show a significant difference according to age (P>0.05) but in boys it was higher than in the girls (P<0.05). Conclusion: According to our findings asthma, allergic rhinitis and eczema have a moderate prevalence in this region of our countr

The Prevalence of Obesity, Technological Device Usage, Physical Activity and their Relationship with Spirometry Indicators among Children in Isfahan City, Iran

Background: The decrease in physical activities following increased usage of computer and digital games has led to serious health consequences in children. This study investigates the prevalence of obesity, cellphone and computer usage and physical activity levels and their relationship with spirometry indicators in Iranian children. Materials and Methods: This is a cross-sectional study during 2013 to 2014 on high-school students in Isfahan, Iran. Sample size determined 1,690 students and sampling performed from 10 girls and 10 boy's high schools, based on multi-staged cluster randomized scheme. A research-made questionnaire was developed to complete by students interview and also contact with teachers and parents and measuring height and weight by researchers. If the asthma was probable (based symptoms and examined by physician) the spirometry was performed.  Results: Overall 1,622 high-school students with the average age of 12.9 (+ 1.1) years were recruited. Prevalence of obesity and overweight were significantly higher in boys (