An investigation in crashworthiness evaluation of aircraft seat cushions at extreme ranges of temperature

Hamid Khademhosseini Beheshti,Hamid Lankarani 대한기계학회 2010 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.24 No.5

This paper obtains a Mathematical Dynamic Model (MADYMO) for occupant lumbar load evaluation under CFR Part 23 and 25 at extreme ranges of temperature. The validation of results is performed by full scale sled test results. Aircraft industries are using viscoelastic polyurethane foams as seat cushion. Visco-elastic foams bring not only more comfort to the passengers in long term sitting but it also maintains more safety during unpredicted crashes and hard landings. Aircraft seat cushions are exposed to varying temperature ranges during their life time. This fact has motivated aircraft industries to evaluate the seat cushion dynamic behavior at extreme ranges of temperatures in addition to what is mentioned in Federal Aviation Administration (FAA) Regulations at room temperature. This research provides a methodology based on simulation and modeling to eliminate, or at least, minimize the number of full scale dynamic sled tests defined by regulations for aircraft seats at extreme ranges of temperature.

The Impact of Supply Chain Management on Organizational Performance and Customer Satisfaction

Hamid Babaei Meybodi,Seyed Hamid Emadi,Tina Roostapisheh,Haniyeh Ghiyasvand Mohammadkha 대한산업공학회 2018 Industrial Engineeering & Management Systems Vol.17 No.3

The present study has been conducted with the purpose of investigating the impact of supply chain management (SCM) on organizational performance and customer satisfaction in two factories in Shiraz Industrial Estate. Therefore, according to the research subject, the variables of supply chain management, organizational performance and also customer satisfaction have been defined. In terms of objective, this is an applied study and in terms of nature and method, this is a descriptive-correlational study. The statistical population consists of 100 people and the sample consists of 80 people. The reliability and validity of research have firstly been examined and then the results were analyzed using SPSS and LISREL. The obtained results indicate the impact of supply chain management on organizational performance and customer satisfaction.

Generation of Retinal Pigmented Epithelium-Like Cells from Pigmented Spheres Differentiated from Bone Marrow Stromal Cell-Derived Neurospheres

Hamid Aboutaleb Kadkhodaeian,Taki Tiraihi,Hamid Ahmadieh,Hossein Ziaei,Narsis Daftarian,Taher Taheri 한국조직공학과 재생의학회 2019 조직공학과 재생의학 Vol.16 No.3

BACKGROUND: Retinal degeneration causes blindness, and cell replacement is a potential therapy. The purpose of this study is to formation of pigmented neurospheres in a simple medium, low-cost, high-performance manner over a short period of time while expressing markers of RPE cells and the activation of specific genes of the pigment cells. Also, these neurospheres have the ability to produce a monolayer of retinal pigment epithelium-like cells (RPELC) with the ability of photoreceptor outer segment phagocytosis. METHODS: BMSC were isolated from pigmented hooded male rats and were immunoreactive to BMSC markers, then converted into neurospheres, differentiated into pigmented spheres (PS), and characterized using Retinal pigment epithelium-specific 65 kDa protein (RPE65), Retinaldehyde-binding protein 1 (CRALBP) and orthodenticle homeobox 2 (OTX2) markers by immunocytochemistry, RT-PCR and RT-qPCR. The PS were harvested into RPELC. The functionality of RPELC was evaluated by phagocytosis of fluorescein-labeled photoreceptor outer segment. RESULTS: The BMSC immunophenotype was confirmed by immunostained for fibronectin, CD90, CD166 and CD44. These cells differentiated into osteogenic and lipogenic cells. The generated neurospheres were immunoreactive to nestin and stemness genes. The PS after 7–14 days were positive for RPE65 (92.76–100%), CRALBP (95.21–100%) and OTX2 (94.88–100%), and after 30 days RT-PCR, qPCR revealed increasing in gene expression. The PS formed a single layer of RPELC after cultivation and phagocyte photoreceptor outer segments. CONCLUSION: Bone marrow stromal stem cells can differentiate into functional retinal pigmented epithelium cells in a simple, low-cost, high-performancemanner over a short period of time. These cells due to expressing theRPELCgenes andmarkers can be used in cell replacement therapy for degenerative diseases including age-relatedmacular degeneration as well as retinitis pigmentosa.

RNAi and miRNA in Viral Infections and Cancers

Mollaie, Hamid Reza,Monavari, Seyed Hamid Reza,Arabzadeh, Seyed Ali Mohammad,Shamsi-Shahrabadi, Mahmoud,Fazlalipour, Mehdi,Afshar, Reza Malekpour Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Since the first report of RNA interference (RNAi) less than a decade ago, this type of molecular intervention has been introduced to repress gene expression in vitro and also for in vivo studies in mammals. Understanding the mechanisms of action of synthetic small interfering RNAs (siRNAs) underlies use as therapeutic agents in the areas of cancer and viral infection. Recent studies have also promoted different theories about cell-specific targeting of siRNAs. Design and delivery strategies for successful treatment of human diseases are becomingmore established and relationships between miRNA and RNAi pathways have been revealed as virus-host cell interactions. Although both are well conserved in plants, invertebrates and mammals, there is also variabilityand a more complete understanding of differences will be needed for optimal application. RNA interference (RNAi) is rapid, cheap and selective in complex biological systems and has created new insight sin fields of cancer research, genetic disorders, virology and drug design. Our knowledge about the role of miRNAs and siRNAs pathways in virus-host cell interactions in virus infected cells is incomplete. There are different viral diseases but few antiviral drugs are available. For example, acyclovir for herpes viruses, alpha-interferon for hepatitis C and B viruses and anti-retroviral for HIV are accessible. Also cancer is obviously an important target for siRNA-based therapies, but the main problem in cancer therapy is targeting metastatic cells which spread from the original tumor. There are also other possible reservations and problems that might delay or even hinder siRNA-based therapies for the treatment of certain conditions; however, this remains the most promising approach for a wide range of diseases. Clearly, more studies must be done to allow efficient delivery and better understanding of unwanted side effects of siRNA-based therapies. In this review miRNA and RNAi biology, experimental design, anti-viral and anti-cancer effects are discussed.

EXPERIMENTAL STUDY OF DESICCANT MATERIAL PRESSURE DROP

Hamdan Abdul Hamid,Chuah Siong Wei,Fathima Rehana Munas,Hamid Yusoff,Mohd Azmi Ismail 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.11

EXPERIMENTAL STUDY OF DESICCANT MATERIAL PRESSURE DROP

Hamdan Abdul Hamid,Chuah Siong Wei,Fathima Rehana Munas,Hamid Yusoff,Mohd Azmi Ismail 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.11

Designing an intelligent emergency response system to minimize the impacts of traffic incidents: a new approximation queuing model

Hamid R. Sayarshad 서울시립대학교 도시과학연구원 2022 도시과학국제저널 Vol.26 No.4

A road traffic accident is an unexpected, irregular activity on the road network that sources a high excess demand relative to the reduced road capacity, resulting in traffic congestion and delays for travellers. The emergency response agencies need to shortly discover, respond to, and clear road traffic accidents in order to decrease the impacts of incidents on traffic congestion. To create an intelligent incident management response system for road networks, real-time data on traffic volumes and accident rates can be used in a queuing model for the allocation/relocation of available resources in response to incidents. In this study, a new queuing-based formulation is proposed for determining the positioning of emergency response units. The greatest benefit of the proposed dynamic model is a reduction in the time it takes response teams to clear accidents, remove debris on the roadway, and restore the normal traffic network. The analysis of actual accident data from New York City demonstrated that the proposed dynamic allocation strategy can contribute to reducing the total waiting time caused by accidents on roads instead of simply minimizing the average response times. The obtained results from testing the presented model revealed that the average costs in terms of the response time and the average delay reduced by 45% and 38%, in comparison to the static deployment model, respectively.

Transformation-Invariant Classification of Persian Printed Digits

Hamid Reza Boveiri 보안공학연구지원센터(IJSIP) 2011 International Journal of Signal Processing, Image Vol.4 No.3

Implementation of Fuzzy Aided Kalman Filter for Tracking a Moving Object in Two-Dimensional Space

Hamid, Khondker Rawan,Talukder, Azzama,Islam, A.K.M. Ehtesanul Korean Institute of Intelligent Systems 2018 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.18 No.2

The work presented in this paper deals with object tracking problem which has vast application prospects. Tracking of surrounding moving objects is important for the development of a navigation system with proper planning and motion techniques. Because of its accurate estimation characteristic, we have used Kalman filter to estimate the motion parameters of a moving object and then fuzzy logic technique is used to improve the performance of Kalman filter. The proposed fuzzy logic controller is a multiple input system with nine rules to adapt noise covariance matrices based on the innovation sequence of a Kalman filter. We have compared the results between conventional Kalman filter and fuzzy aided Kalman filter. The software based simulation results verified that this unique fuzzy aided Kalman filter has a positive effectiveness for the object tracking problem over conventional Kalman filter because of its capability to recover filter divergence problem.

Selection of Viscous Damping Model for Evaluation of Seismic Responses of Buildings

Hamid Zand,Jalal Akbari 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.11

Users of structural analysis software commonly apply the Rayleigh damping model as a default option for analyzing of structures. When a distributed plasticity model is utilized in the numerical models, the structural responses are not found to be sensitive to the damping models; even the Rayleigh damping model leads to the reasonable seismic results. Moreover, the lower bounds and upper bounds of the demands are sensitive to the type of damping model. In this paper, the effects of viscous damping models in the seismic demands of moment and concentrically braced steel frames are carefully investigated. For this purpose, seven viscous damping models are considered using the different forms of the stiffness matrices in the finite-element modeling. The declared structural systems are modeled against several strong ground motion records in OpenSees environment. Then, the seismic responses such as drifts, accelerations and base shears are compared for the aforementioned damping models. The main result of this research is that applying Rayleigh damping model, as a default option for structural analyzing software will produce underestimated responses. In addition, it is shown that no matter which type of stiffness matrix is used in the stiffness proportional damping model. Therefore, using initial stiffness matrix is cost efficient, particularly in time-consuming nonlinear analyses.