309 research outputs found

    GENETIC ALGORITHM APPLIED TO OPTIMIZATION OF THE SHIP HULL FORM WITH RESPECT TO SEAKEEPING PERFORMANCE

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    Hull form optimization from a hydrodynamic performance point of view is an important aspect in preliminary ship design. This study presents a computational method to estimate the ship seakeeping in regular head waves. In the optimization process, the genetic algorithm (GA) is linked to the computational method to obtain an optimum hull form by taking into account the displacement as a design constraint. New hull forms are obtained from the well-known S60 hull and the classical Wigley hull taken as initial hulls in the optimization process at two Froude numbers (Fn=0.2 and Fn=0.3). The optimization variables are a combination of ship hull offsets and main dimensions. The objective function of the optimization procedure includes the peak values for vertical absolute motion at the centre of gravity (CG) and the bow point (0.15Lwl) behind the forward perpendicular (FP)

    GENETIC ALGORITHM APPLIED TO OPTIMIZATION OF THE SHIP HULL FORM WITH RESPECT TO SEAKEEPING PERFORMANCE

    Get PDF
    Hull form optimization from a hydrodynamic performance point of view is an important aspect in preliminary ship design. This study presents a computational method to estimate the ship seakeeping in regular head waves. In the optimization process, the genetic algorithm (GA) is linked to the computational method to obtain an optimum hull form by taking into account the displacement as a design constraint. New hull forms are obtained from the well-known S60 hull and the classical Wigley hull taken as initial hulls in the optimization process at two Froude numbers (Fn=0.2 and Fn=0.3). The optimization variables are a combination of ship hull offsets and main dimensions. The objective function of the optimization procedure includes the peak values for vertical absolute motion at the centre of gravity (CG) and the bow point (0.15Lwl) behind the forward perpendicular (FP)

    Digital Analysis of Soft Tissue Nasal Anatomy for Individual Treatment Planning

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    Objective: Changing contour lines of the external nose following traumatic, aesthetic and tumour surgeries have become very trendy. The goal of this research is to study the several soft tissue landmarks, measurements (linear distances, ratios, angles) of the external nose and its nasal indicis using a computer program. Methods: Face region were taken a photographs of the two hundred adults. Analyses of linear (the lengths of nares, nasal bridge, and columella and nose height, nares width) and angular analyses (angles of nasofrontal, nasolabial and nasal tip) were computed and averaged for gender with age. As for the shape of the nose, it was categorized as subunits: nasal tip (sharp, normal, wide, protrusive and asymmetric), nasal base (normal, wide, asymmetric) nasal alae (normal, thick, thin, asymmetric), nares (normal, horizontal and asymmetric) and columella (normal, wide, short and bifid) nasal base, nares, nasal alae, columella and classified subunit as normal, protrusive, sharp, asymmetric, and wide. Results: The nose height have to 49.05 ± 3.48 mm in young male adults, 50.37 ± 2.33 mm in young female adults. Distance lengthwise the nasal bridge have to 48.60 ± 3.24 in males, 37.09 ± 5.49 females. The two mean measured nasal lengths were significantly greater in men. At the same time, angular measurements for nasolabial and interalar were higher in males. Nasal tip angle was 127.47 ± 82.9° in males, 75.8° in females. On average, young male adults had larger nasal linear distances such as nasal bridge length, nares lengths and nares widths relation of height than young female adults (p;\u3c0.01); No gender differences were observed for columella widths and to nose height ratio (p;\u3c0.01). The nasofrontal, nasal tip, nasolabial and interalar angles showed statistically significant differences among young male adults and young female adults (p;\u3c0.05). The nasolabial angle exhibited considerable variability. The shape details of nares was showed large variability. Nasal base, nasal tip and nasal alae shapes were similar, nares asymmetry was more frequently compared with other features. Conclusions: The Anatolian people’s nose exhibits wide nasal tip, has a wider nasal base, and is more thicker at the alae, with wider definition of the columella. The significant gender differences of nasal shapes were found. The wide and sharp features of nasal tip were related to an important features in men, whereas asymmetric nares were dominant in young female adults. Using digitized reference details, this study helped define the best cosmetic surgery recreate the nose and increase the success of customized therapy. Also, our findings facial alteratios, facial reconstruction, personal identification, Trauma assessments may also have data banks based on age and gender

    Hysteresis Nonlinearity Identification Using New Preisach Model-Based Artificial Neural Network Approach

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    Preisach model is a well-known hysteresis identification method in which the hysteresis is modeled by linear combination of hysteresis operators. Although Preisach model describes the main features of system with hysteresis behavior, due to its rigorous numerical nature, it is not convenient to use in real-time control applications. Here a novel neural network approach based on the Preisach model is addressed, provides accurate hysteresis nonlinearity modeling in comparison with the classical Preisach model and can be used for many applications such as hysteresis nonlinearity control and identification in SMA and Piezo actuators and performance evaluation in some physical systems such as magnetic materials. To evaluate the proposed approach, an experimental apparatus consisting one-dimensional flexible aluminum beam actuated with an SMA wire is used. It is shown that the proposed ANN-based Preisach model can identify hysteresis nonlinearity more accurately than the classical one. It also has powerful ability to precisely predict the higher-order hysteresis minor loops behavior even though only the first-order reversal data are in use. It is also shown that to get the same precise results in the classical Preisach model, many more data should be used, and this directly increases the experimental cost

    A Survey of Relationship between Islamic Tolerance of Managers and Organizational Health

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    The present study is an attempt to survey the relationship between the manager’s tolerance and organizational health. The concept of tolerance, within the scope of this paper is a directional and moderate action to deal with controversial and opposite directions. The aspects of Islamic tolerance include ontological, anthropological, epistemological, and axiological foundations. The elements of organizational health are institutional unity, initiating structure, consideration, and resource support, moral and academic emphasis. Study population was comprised of 45 employees of Esfarayen University of Technology and Engineering. Research tools were a standard questionnaire of organizational and researcher-designed management’s tolerance questionnaire. Data analyses were carried out using correlation and simple regression tests. The study results indicated a significant relationship between organizational health and Islamic tolerance. It was concluded, thereby, that observation of principles of tolerance in the organization boosts organizational health. In addition, maximum mean point was obtained among descriptive indices of organizational health by consideration and initiating structure and by anthropology among elements of toleranc

    Using Intra-Aortic Balloon Pump for Management of Cardiogenic Shock Following Aluminum Phosphide Poisoning; Report of 3 Cases

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    Introduction: Aluminium phosphide (Alp) poisoning mortality rate has been reported as high as 70-100%, and refractory hypotension and cardiogenic shock are the two most common presentations leading to death. Due to lack of specific antidote, all treatments are focused on supportive care and recently, intra-aortic balloon pump (IABP) has been suggested to treat cardiogenic shock resulting from toxic myocarditis. In the current paper, we introduce three Alp poisoned patients for whom IABP was applied to manage their refractory shock. Case presentation: Two men and one woman who were admitted to emergency department (ED) of Imam Reza academic Hospital, Mashhad, Iran due to intentional Alp poisoning are reported. The cases visited the ED shortly after ingestion and nearly all of them showed hypotension, tachycardia and metabolic acidosis during early hospitalization. Due to persistent shock state, despite receiving intravenous fluid therapy and vasopressor agents, IABP insertion was performed in these cases. Finally, one of them survived and the other two died. Conclusion: It still cannot be decided whether IABP insertion is effective in cases of Alp poisoning or not. It might be reasonable to try this intervention along with other conservative treatments in patients who survive more than 12 hours and consistently suffer from refractory hypotension

    Vocabulary instruction through blended learning and multimedia softwares in Iranian ESP classes

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    The purpose of this study was to investigate the impact of blended learning and multimedia softwares on Iranian ESP students' vocabulary learning. To this end, 120 Iranian ESP learners were assigned to two groups: the experimental and control groups. The experimental group received instructions through multimedia softwares while the control group received traditional instructions. The data were collected through a vocabulary posttest and classroom observations. The results indicated the great level of disparity between the two groups of learners regarding their acquisition of new vocabulary - in other words, multimedia softwares had positive effect on students' vocabulary learning. In addition, learning with technology also showed positive activity engagement. Based on the current study, suggestions were made on how multimedia softwares can be adopted and incorporated more effectively in ESP classes

    Comparison of new Biomarkers in the Diagnosis of Perinatal Asphyxia

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      Objectives Precise and early diagnosis of neonatal asphyxia may improve its outcomes. New studies aim to identify diagnostic biomarkers in neonates at risk for brain damage. The current study was designed to evaluate the diagnostic value of new biomarkers neonatal asphyxia. Materials & Methods This prospective study was conducted with an available sampling of infants upper 35 weeks of gestational age, including neonates with asphyxia (case group) and healthy controls, 2014-2022, in Ghaem Hospital, Mashhad, Iran. Data collection was performed utilizing a researcher-made questionnaire, including maternal and neonatalcharacteristics, as well as clinical and laboratory evaluation. Serum umbilical cord levels of interleukin-6 (IL6), interleukin-1-beta (IL- 1β), pro-oxidant-antioxidant balance (PAB), and heat shock protein-70 (HSP70), as well as nucleated red blood cells count (NRBC), were determined. Data were analyzed by t-test, Chi-square, receiver operating characteristic (ROC), and regression models. Results Variables interleukin-6(IL6) (P<0.0001), IL1β (P<0.0001), PAB (P<0.0001), NRBC/100WBC (P<0.0001) and HSP70 (P<0.0001) in the two groups, the difference was statistically significant. In the diagnosis of asphyxia, the most sensitive marker (89%) was IL1β more than 2.39 pg/ml and HSP 70 upper than 0.23 ng/ml while IL6 higher than 9pg/ml determined as the most specific marker (85%). For the diagnosis of asphyxia, combination of HSP + PAB and IL6 + lL1b + PAB + NRBC/100WBC possesses the prediction power of 93.2% and 87.3% respectively. Conclusion According to data analysis, the combination of new biochemical markers (NRBC count, IL6, IL1β, PAB, HSP 70) could be a reliable marker for the diagnosis of infants with asphyxia. The composition of the HSP + PAB indicators is more valid predictions 93.2% compared to the other combined indicators for the diagnosis of asphyxiated neonates. PAB values correlate with the severity of asphyxia. &nbsp

    Nanotechnology and supercritical fluids

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    Supercritical fluid (SCF) technology has become an important tool of materials processing in the last two decades. Supercritical CO2 and H2O are extensively being used in the preparation of a great variety of nanomaterials. The interest in the preparation and application of nanometer size materials is increasing since they can exhibit properties of great industrial interest. Several techniques have been proposed to produce nanomaterials using supercritical fluids. These processes, taking advantage of the specific properties of supercritical fluids, are generally flexible, more simplified and with a reduced enviromental impact. The result is that nanomaterials with potentially better performances have been obtained. We propose a critical review of the supercritical based techniques applied to the production of nanoparticles materials.Keywords: Supercritical fluids; Nanoparticles; SCF technology; RESS; SAS
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