H_∞ filter design for offshore platforms via sampled-data measurements

Kazemy, Ali Techno-Press 2018 Smart Structures and Systems, An International Jou Vol.21 No.2

This paper focuses on the $H_{\infty}$ filter design problem for offshore steel jacket platforms. Its objective is to design a full-order state observer for offshore platforms in presence of unknown disturbances. To make the method more practical, it is assumed that the measured variables are available at discrete-time instants with time-varying sampling time intervals. By modelling the sampling intervals as a bounded time-varying delay, the estimation error system is expressed as a time-delay system. As a result, the addressed problem can be transformed to the problem of stability of dynamic error between the system and the state estimator. Then, based on the Lyapunov-Krasovskii Functional (LKF), a stability criterion is obtained in the form of Linear Matrix Inequalities (LMIs). According to the stability criterion, a sufficient condition on designing the state estimator gain is obtained. In the end, the proposed method is applied to an offshore platform to show its effectiveness.

Consecutive Synchronization of a Delayed Complex Dynamical Network via Distributed Adaptive Control Approach

Ali Kazemy,Jinde Cao 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.6

In this paper, a consecutive synchronization scheme is investigated to synchronize the nodes of a delayed complex dynamical network with an isolated node via an adaptive control approach. The specific feature of this scheme consists in the structure of the communication links: a communication connection is required between the isolated node and one selected node in the network, and further communication links exist between any node and one neighbor node. In this way, all nodes are connected together like a chain. Based on Lyapunov-Krasovskii theory, some conditions are obtained in the form of linear matrix inequalities to guarantee the consecutive synchronization by the designed distributed adaptive control. To make this synchronization scheme more practical, no constraints have been considered for coupling connection matrix such as being symmetric or zero row sum. Finally, a numerical example is presented to demonstrate the effectiveness of the proposed method.

H filter design for offshore platforms via sampled-data measurements

Ali Kazemy 국제구조공학회 2018 Smart Structures and Systems, An International Jou Vol.21 No.2

This paper focuses on the H filter design problem for offshore steel jacket platforms. Its objective is to design a full-order state observer for offshore platforms in presence of unknown disturbances. To make the method more practical, it is assumed that the measured variables are available at discrete-time instants with time-varying sampling time intervals. By modelling the sampling intervals as a bounded time-varying delay, the estimation error system is expressed as a time-delay system. As a result, the addressed problem can be transformed to the problem of stability of dynamic error between the system and the state estimator. Then, based on the Lyapunov-Krasovskii Functional (LKF), a stability criterion is obtained in the form of Linear Matrix Inequalities (LMIs). According to the stability criterion, a sufficient condition on designing the state estimator gain is obtained. In the end, the proposed method is applied to an offshore platform to show its effectiveness.

Field Study of Effects of Night Shifts on Cognitive Performance, Salivary Melatonin, and Sleep

Kazemi, Reza,Motamedzade, Majid,Golmohammadi, Rostam,Mokarami, Hamidreza,Hemmatjo, Rasoul,Heidarimoghadam, Rashid Occupational Safety and Health Research Institute 2018 Safety and health at work Vol.9 No.2

Background: Night shift work is associated with many problems such as sleep deprivation, sleepiness, decreased cognitive performance, increased human errors, and fatigue. This study set out to measure cognitive performance, melatonin rhythms, and sleep after different consecutive night shifts (7 vs. 4) among control room operators (CORs). Methods: The participants included 60 CORs with a mean age of 30.2 years (standard deviation, 2.0) from a petrochemical complex located in Southern Iran. Cognitive performance was assessed using the n-back task and continuous performance test. To evaluate melatonin, saliva was collected and tested by enzyme-linked immunosorbent assay. To assess sleep and sleepiness, the Pittsburgh Sleep Quality Index and Karolinska Sleepiness Scale were used, respectively. Results: Individuals who worked 7 consecutive night shifts had a significantly better cognitive performance and sleep quality than those who worked 4 consecutive night shifts. However, salivary melatonin profile and sleepiness trend were not affected by shift type. Conclusion: The main duty of CORs working night shifts at the studied industry included managing safety-critical processes through complex displays; a responsibility that demands good cognitive performance and alertness. It is suggested that an appropriate number of consecutive night shifts in a rotating shift system should be planned with the ultimate aim of improving CROs performance/alertness and enhancing safety.

BNBTS More than Brominating Agent: Green and One-pot Route for the C-N Bond Formation in Water from Alkenes

Kazemi, Foad,Kakroudi, Mazaher Abdollahi Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.2

In this paper, in addition to introducing efficient method for bromohydrin and bromoether preparation, simple, green and efficient method to C-N bond formation from alkene and N,N'-Dibromo-N,N'-1,2-ethanediyl-bis(p-toluenesulfonamide) [BNBTS] in water was investigated. The reaction between alkenes, ${\beta}$-cyclodexterin, and BNBTS took place in water afterward, by making media basic; it will give the corresponding valuable building blocks in good yields (45-79%).

Selective Transport of Lead(II) through a Bulk Liquid Membrane Using a Cooperative Carrier Composed of Benzylaza-12-crown-4 and Oleic Acid

Kazemi, Sayed Yahya,Shamsipur, Mojtaba Korean Chemical Society 2005 Bulletin of the Korean Chemical Society Vol.26 No.6

A chloroform membrane system containing a given mixture of benzylaza-12-crown-4 and oleic acid is introduced for the selective and efficient transport of $Pb^{2+}$ ion. The transport was capable of moving metal ions ‘up-hill’. In the presence of ${S_2O_3}^{2-}$ion as a suitable metal ion acceptor in the receiving phase, the amount of lead ion transport across the liquid membrane after 150 minutes is (95.0 ${\pm}$ 1.7)%. The selectivity and efficiency of lead transport from aqueous solution containing $Tl^+,\;Ag^+,\;Mg^{2+},\;Ca^{2+},\;Co^{2+},$ $Ni^{2+},\;Cu^{2+},\;Zn^{2+},\;Hg^{2+}$ and $Cd^{2+}$were investigated. In the presence of thiosulfate as a suitable masking agent in the source phase, the interfering effects of $Ag^+\;and\;Cu^{2+}$ were diminished drastically.

A curtain traveling pluviator to reconstitute large scale sand specimens

Kazemi, Majid,Bolouri, Jafar B. Techno-Press 2018 Geomechanics & engineering Vol.14 No.2

The preparation of repeatable and uniformly reconstituted soil specimens up to the specified conditions is an essential requirement for the laboratory tests. In this study for large samples replication, the simultaneous usage of the traveling pluviation and curtain raining technique is used to develop a new method, called the curtain travelling pluviator (CTP). This simple and cost effective system is based on the air pluviation approach, whilst reducing the sample production time, can reproduce uniform samples with relative densities ranging from 25% to 96%. In order to investigate the resulting suitability and uniformity from the proposed method, a series of tests is performed. The effect of curtain traveling velocity, curtain width, drop height, and flow rate on the parameters of the sample is thoroughly investigated. Increase in the curtain velocity and drop height leads to the increase in relative density for the sand specimen. Increase in curtain width typically resulted in the reduction of relative density. Test results reveal that the terminal drop height for the sand specimen in this study is more than 500 mm. Relative density contour lines are presented that can be utilized in optimizing the drop height and curtain width parameters. Sample uniformity in the vertical and horizontal orientation is investigated through the sampling containers. Increasing relative density tends to result in the higher sample repeatability and uniformity.

Effects of phosalone consumption via feeding with or without sodium bentonite on performance, blood metabolites and its transition to milk of Iranian Baluchi sheep

( Mohsen Kazemi ),( Ameneh Eskandary Torbaghan ),( Abdoul Mansour Tahmasbi ),( Reza Valizadeh ),( Abbas Ali Naserian ) 한국동물자원과학회 2017 한국축산학회지 Vol.59 No.5

Background: Transfer of pesticides from environment to animal products is inevitable, so the purpose of the present work was to evaluate phosalone consumption via feeding with or without sodium bentonite (SB) on performance, blood metabolites and its transition to milk of Iranian Baluchi sheep. Methods: Twenty Baluchi ewes were divided into four treatments (P1 as control, P2, P3, and P4) of five animals in which phosalone, an organophosphate pesticide, was given via diet (only for P2 and P3) at a dose of 280 mg/ sheep/day for 63 consecutive days. The SB (32 g/sheep/day; for P3 and P4) was also evaluated for its ability to reduce deleterious effects of phosalone in the sheep diets. The control group (P1) did not receive any phosalone and SB during the experiment. Sampling was conducted in two periods of time including weeks 5 and 9. Results: Phosalone residues were observed in the milk samples of P2 and P3 groups during two sampling periods. During period 1, the transfer rate of phosalone from feed to milk was 0.23 and 0.02%, respectively for the contaminated diets (P2 and P3), which is relatively similar to period 2 (0.22 and 0.02%). Only 0.34 (period 1) and 0. 36% (period 2) of phosalone residue are excreted in the feces of P2 group following its daily consumption. Transfer of phosalone from feed to milk was affected (P < 0.05) by the dietary inclusion of a commercial SB, as it (SB) decreased excretion of phosalone via milk (P3). The phosalone and SB alone or together had no significant effect (P > 0.05) on the dry matter intake (DMI) and body weight (BW) gain, but feed efficiency, milk production, milk fat, dry matter (DM) and organic matter (OM) digestibility, acetylcholinesterase (AChE) inhibitory activity, hemoglobin (Hb), red blood cell (RBC), serum glutamic pyruvic transaminase (SGPT), serum glutamic oxaloacetic transaminase (SGOT), albumin and mean corpuscular hemoglobin concentration (MCHC) affected by the treatments in period 1 or 2 (P < 0.05). The Hb, RBC, and MCHC were significantly decreased (P < 0.05) by about 9.72, 20.77, and 9.71%, respectively in the group P2 as compared to those of the control group during period 1. The AChE inhibitory activity (period 1 and 2) significantly increased when phosalone administered via the diet (P < 0.05). Conclusions: Although there were no adverse effects on the performance of sheep following the intake of phosalone alone (P2 vs. P1), but other research on the long and short times to the phosalone in high and low doses with more animals is suggested. Overall, compared to the control group, addition of SB in the diet of sheep improved nutrient digestibility, animal performance, and milk health.

Concussion Knowledge among Sport Chiropractors

( Mohsen Kazemi ),( Mary Emma Bogumil ),( Khushboo Vora ) 국제태권도학회 2017 Journal of the International Association for Taekw Vol.4 No.1

Purpose: The objective of this study is to investigate the degree of knowledge that sports chiro-practors have in regard to concussion diagnosis and management. Methods: An online, previously-used survey was administered to Sport Chiropractic Fellows from the Royal College of Chiropractic Sports Sciences - Canada (n = 44). This survey, which was scored from 0 to 9, asked nine questions regarding participants` concussion knowledge. The number of correct responses was used as the concussion knowledge score. Results: Sport chiropractors scored slightly higher on the survey when compared to chiropractic residents (mean = 5.57 vs. 5.25; t = 2.12; p = 0.04) and to fourth year chiropractic interns (mean = 5.57 vs 5.2; t = 2.45; p = 0.02), and the difference was statistically significant. Gender, personal concussion history, previous acutely concussed patient experience, and post concussive patient syndrome experience were not predictive of the number of questions answered correctly. As an alternative method of scoring the survey, we scored Part 2 of the questionnaire (concussion knowledge) by giving a point for each correct selection. This method measured the level of knowledge better than considering all correct answers as one point. The average score of the re-spondents was 29.84 out of 35 or 85.26% (SD = 2.93, 95% CI = 28.97, 30.71). With this method of scoring, the sport chiropractors did well. A few knowledge gaps were identified in the sample population. Conclusions: Sports chiropractors prove to possess the skills and knowledge to diagnose and manage concussion. However, although sports chiropractors excel at identifying the definition and mechanism of concussion, knowledge gaps regarding diagnosis and management of concus-sion were found in the sample population.

The effect of a blue enriched white light on salivary antioxidant capacity and melatonin among night shift workers

Reza Kazemi,Rasoul Hemmatjo,Mokarami Hamidreza 대한직업환경의학회 2018 대한직업환경의학회지 Vol.30 No.-

Background: Because of their positive impact on individuals’ performance and alertness, blue enriched white light sources are gaining popularity in households and industries. However, these sources of blue light spectrum may cause oxidative stress. On the other hand, there are no empirical studies investigating the negative effect of blue enriched white light on oxidative stress. Thus, the current study aimed at empirical assessment of the effect of such light sources on oxidative stress among night shift workers. Methods: The study, which adopted a cross-sectional design, focused on 30 control room operators of a petrochemical complex. The subjects followed a shift-work schedule comprising 7 night shifts, 7 day shifts, and 7 days off. The subjects were exposed to 6500 K, 3000 K, and 17,000 K light sources (which have various degrees of blue light) during three consecutive work cycles, with each cycle lasting for 7 nights. In each light condition, three salivary measurements were conducted (at the beginning, in the middle, and at the end of the shift). The measurements were used to assess catalase (CAT), total thiol molecules (TTG), and total antioxidant capacity (TAC), and melatonin. Results: The results of repeated measures ANOVA showed that there was no significant difference among various light conditions with regard to salivary biomarkers (catalase, total thiol molecules, and total antioxidant capacity). There was however a significant difference between 3000 K and 17,000 K conditions with regard to the concentration of salivary melatonin (p = 0.001). Conclusion: Given that there was no significant difference among various light conditions in terms of biomarkers, it is concluded that using sources of light with high color temperature can be recommended. Nonetheless, because of the limitations of the present study (e.g. short period of intervention), it is suggested that care should be exercised in using such light sources.