Effective number of mega-bracing, in order to minimize shear lag

Zahiri-Hashemi, Rouzbeh,Kheyroddin, Ali,Farhadi, Basir Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.48 No.2

In this paper, influence of geometric configurations of multi-story bracing on shear lag behaviour of braced tube structures is investigated. The shear lag of 24-, 36- and 72-story braced tube structures are assessed considering all possible configurations of overall X and Chevron bracing types. Based on the analytical results, empirical equations, useful for the preliminary design phase, are proposed to provide the optimum number of stories that braced, in order to exert minimum shear lag on structures. Studying the interaction behaviour of a tube and different bracing types along with paying attention to the shear lag behaviour, a better explanation about the reasons behind the efficiency of a specific bracing module in decreasing the shear lag is developed. The analytical results show that there are distinct differences between the anatomy of braced tube structures with X and Chevron bracing regarding the shear lag behaviour.

Determination of safe mud weight window based on well logging data using artificial intelligence

Zahiri, Javad,Abdideh, Mohammad,Golab, Elias Ghaleh 한국자원공학회 2019 Geosystem engineering Vol.22 No.4

Identification of different stresses applied to the environment surrounding wellbore via different processes, and combining these data with mechanical parameters of common formations in hydrocarbon reservoirs comprise a key for addressing a wide range of costly problems and issues in the oil industry. In the present research, first, an attempt was made to construct mechanical earth model based on well logging data, elastic moduli of rock, and appropriate failure criteria for the final purpose of calculating and determining safe mud weight window (SMWW). Finally, appropriate artificial intelligence and machine-learning algorithms were used to establish a relationship between well logging data and SMWW, which could be used to calculate and predict SMWW without using associated relationships with the mechanical earth model. This might end up with a decreased number of required parameters for calculating SMWW, including uniaxial compressive strength. In the present research, the learning process was conducted using datasets from three wells, two of which provided training data, with the other one used as testing data. The prepared model was finally used to predict corresponding pressures to SMWW and baseline pressures for hydraulic fracturing operation. The model gave a coefficient of determination of 0.93 when applied to the testing data using support vector regression algorithm with radial basis function kernel, indicating large capabilities of this algorithm in predicting non-foreseen data.

Ontology for Symptomatic Treatment of Multiple Sclerosis

Misagh Zahiri Esfahani,Maryam Ahmadi,Iman Adibi 대한의료정보학회 2022 Healthcare Informatics Research Vol.28 No.4

Objectives: Symptomatic treatment is an essential component in the overall treatment of multiple sclerosis (MS). However, knowledge in this regard is confusing and scattered. Physicians also have challenges in choosing symptomatic treatment based on the patient’s condition. To share, update, and reuse this knowledge, the aim of this study was to provide an ontology for MS symptomatic treatment. Methods: The Symptomatic Treatment of Multiple Sclerosis Ontology (STMSO) was developed according to Ontology Development 101 and a guideline for developing good ontologies in the biomedical domain. We obtained knowledge and rules through a systematic review and entered this knowledge in the form of classes and subclasses in the ontology. We then mapped the ontology using the Basic Formal Ontology (BFO) and Ontology for General Medical Sciences (OGMS) as reference ontologies. The ontology was built using Protégé Editor in the Web Ontology Language format. Finally, an evaluation was done by experts using criterion-based approaches in terms of accuracy, clarity, consistency, and completeness. Results: The knowledge extraction phase identified 110 articles related to the ontology in the form of 626 classes, 40 object properties, and 139 rules. Five general classes included “patient,” “symptoms,” “pharmacological treatment,” “treatment plan,” and “measurement index.” The evaluation in terms of standards for biomedical ontology showed that STMSO was accurate, clear, consistent, and complete. Conclusions: STMSO is the first comprehensive semantic representation of the symptomatic treatment of MS and provides a major step toward the development of intelligent clinical decision support systems for symptomatic MS treatment.

Effective number of mega-bracing, in order to minimize shear lag

Rouzbeh Zahiri-Hashemi,Ali Kheyroddin,Basir Farhadi 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.48 No.2

In this paper, influence of geometric configurations of multi-story bracing on shear lag behaviour of braced tube structures is investigated. The shear lag of 24-, 36- and 72-story braced tube structures are assessed considering all possible configurations of overall X and Chevron bracing types. Based on the analytical results, empirical equations, useful for the preliminary design phase, are proposed to provide the optimum number of stories that braced, in order to exert minimum shear lag on structures. Studying the interaction behaviour of a tube and different bracing types along with paying attention to the shear lag behaviour, a better explanation about the reasons behind the efficiency of a specific bracing module in decreasing the shear lag is developed. The analytical results show that there are distinct differences between the anatomy of braced tube structures with X and Chevron bracing regarding the shear lag behaviour.

A study on the seismic behavior of Reinforced Concrete (RC) wall piers strengthened with CFRP sheets: A pushover analysis approach

Fatemeh Zahiri,Ali Kheyroddin,Majid Gholhaki 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.88 No.5

The use of reinforced concrete (RC) shear walls (SW) as an efficient lateral load-carrying system has gained recent attention. However, creating openings in RC shear walls is unavoidable due to architectural requirements. This reduces the walls' strength and stiffness, resulting in the development of wall piers. In this study, the cyclic behavior of RC shear walls with openings, reinforced with carbon fiber reinforced polymer (CFRP) sheets in various patterns, was numerically investigated. Finite element analysis (FEA) using ABAQUS software was employed. Additionally, the retrofitting of sub-standard buildings (5, 10, and 15-story structures) designed based on the old and new versions of the Iranian Code of Practice for Seismic-Resistant Structures was evaluated. Nonlinear static analyses, specifically pushover analyses, were conducted on the structures. The best pattern of CFRP wrapping was determined and utilized for retrofitting the sub-standard structures. Various structural parameters, such as load-carrying capacity, ductility, stress contours, and tension damage contours, were compared to assess the efficiency of the retrofit solution. The results indicated that the load-carrying capacity of the sub-standard structures was lower than that of standard ones by 57%, 69%, and 67% for 5, 10, and 15-story buildings, respectively. However, the retrofit solution utilizing CFRP showed promising results, enhancing the capacity by 10-25%. The retrofitted structures demonstrated increased yield strength, ultimate strength, and ductility through CFRP wrapping and effectively prevented wall slipping.

Body size affects the evolution of hidden colour signals in moths

Kang, Changku,Zahiri, Reza,Sherratt, Thomas N. Royal Society 2017 Proceedings, Biological sciences Vol.284 No.1861

<P>Many cryptic prey have also evolved hidden contrasting colour signals which are displayed to would-be predators. Given that these hidden contrasting signals may confer additional survival benefits to the prey by startling/intimidating predators, it is unclear why they have evolved in some species, but not in others. Here, we have conducted a comparative phylogenetic analysis of the evolution of colour traits in the family Erebidae (Lepidoptera), and found that the hidden contrasting colour signals are more likely to be found in larger species. To understand why this relationship occurs, we present a general mathematical model, demonstrating that selection for a secondary defence such as deimatic display will be stronger in large species when (i) the primary defence (crypsis) is likely to fail as its body size increases and/or (ii) the secondary defence is more effective in large prey. To test the model assumptions, we conducted behavioural experiments using a robotic moth which revealed that survivorship advantages were higher against wild birds when the moth has contrasting hindwings and large size. Collectively, our results suggest that the evolutionary association between large size and hidden contrasting signals has been driven by a combination of the need for a back-up defence and its efficacy.</P>

A NOTE ON MINIMAL PRIME IDEALS

Mohammadi, Rasul,Moussavi, Ahmad,Zahiri, Masoome Korean Mathematical Society 2017 대한수학회보 Vol.54 No.4

Let R be a strongly 2-primal ring and I a proper ideal of R. Then there are only finitely many prime ideals minimal over I if and only if for every prime ideal P minimal over I, the ideal $P/{\sqrt{I}}$ of $R/{\sqrt{I}}$ is finitely generated if and only if the ring $R/{\sqrt{I}}$ satisfies the ACC on right annihilators. This result extends "D. D. Anderson, A note on minimal prime ideals, Proc. Amer. Math. Soc. 122 (1994), no. 1, 13-14." to large classes of noncommutative rings. It is also shown that, a 2-primal ring R only has finitely many minimal prime ideals if each minimal prime ideal of R is finitely generated. Examples are provided to illustrate our results.

ON ANNIHILATIONS OF IDEALS IN SKEW MONOID RINGS

Mohammadi, Rasul,Moussavi, Ahmad,Zahiri, Masoome Korean Mathematical Society 2016 대한수학회지 Vol.53 No.2

According to Jacobson [31], a right ideal is bounded if it contains a non-zero ideal, and Faith [15] called a ring strongly right bounded if every non-zero right ideal is bounded. From [30], a ring is strongly right AB if every non-zero right annihilator is bounded. In this paper, we introduce and investigate a particular class of McCoy rings which satisfy Property (A) and the conditions asked by Nielsen [42]. It is shown that for a u.p.-monoid M and ${\sigma}:M{\rightarrow}End(R)$ a compatible monoid homomorphism, if R is reversible, then the skew monoid ring R * M is strongly right AB. If R is a strongly right AB ring, M is a u.p.-monoid and ${\sigma}:M{\rightarrow}End(R)$ is a weakly rigid monoid homomorphism, then the skew monoid ring R * M has right Property (A).

SCM435 강의 라운드-오발 및 스퀘어-다이아몬드 압연 공정에서의 AGS 분포

이호원(H.W.Lee),S.H.Zahiri,P.D.Hodgson,임용택(Y.T.Im) 한국소성가공학회 2004 압연 심포지엄 Vol.2004 No.8

Neural Network Optimization by Genetic Algorithms for the Audio Classification to Speech and Music

Saeed Balochian,Emad Abbasi Seidabad,Saman Zahiri Rad 보안공학연구지원센터(IJSIP) 2013 International Journal of Signal Processing, Image Vol.6 No.3