On Some Properties of Riemannian Manifolds with a Generalized Connection

Dehkordy, Azam Etemad Department of Mathematics 2016 Kyungpook mathematical journal Vol.56 No.4

In this paper we study some properties of submanifolds of a Riemannian manifold equipped with a generalized connection $\hat{\nabla}$. We also consider almost Hermitian manifolds that admits a special case of this generalized connection and derive some results about the behavior of this manifolds.

Optimizing Machine Learning Approach Based on Fuzzy Logic in Text Summarization

Farshad Kyoomarsi,Hamid Khosravi,Esfandiar Eslami,Pooya Khosravyan Dehkordy 보안공학연구지원센터 2009 International Journal of Hybrid Information Techno Vol.2 No.2

With the proliferation of the Internet and the huge amount of data it transfers, automatic text summarization is becoming more important. In this paper we first analyze some state of the art methods to text summarization., We also try to analyze one of the previous text summarization methods, "Machine learning Approach", and eliminate its shortcomings .Finally we present an approach to the design of an automatic text summarizer that generates a summary using fuzzy logic to obtain better results compared to previous methods.

The antinociceptive effect of artemisinin on the inflammatory pain and role of GABAergic and opioidergic systems

Dehkordi, Faraz Mahdian,Kaboutari, Jahangir,Zendehdel, Morteza,Javdani, Moosa The Korean Pain Society 2019 The Korean Journal of Pain Vol.32 No.3

Background: Pain is a complex mechanism which involves different systems, including the opioidergic and GABAergic systems. Due to the side effects of chemical analgesic agents, attention toward natural agents have been increased. Artemisinin is an herbal compound with widespread modern and traditional therapeutic indications, which its interaction with the GABAergic system and antinoniceptive effects on neuropathic pain have shown. Therefore, this study was designed to evaluate the antinociceptive effects of artemisinin during inflammatory pain and interaction with the GABAergic and opioidergic systems by using a writhing response test. Methods: On the whole, 198 adult male albino mice were used in 4 experiments, including 9 groups (n = 6) each with three replicates, by intraperitoneal (i.p.) administration of artemisinin (2.5, 5, and 10 mg/kg), naloxone (2 mg/kg), bicuculline (2 mg/kg), saclofen (2 mg/kg), indomethacin (5 mg/kg), and ethanol (10 mL/kg). Writhing test responses were induced by i.p. injection of 10 mL/kg of 0.6% acetic acid, and the percentage of writhing inhibition was recorded. Results: Results showed significant dose dependent anti-nociceptive effects from artemisinin which, at a 10 mg/kg dose, was statistically similar to indomethacin. Neither saclofen nor naloxone had antinociceptive effects and did not antagonize antinociceptive effects of artemisinin, whereas bicuculline significantly inhibited the antinocicptive effect of artemisinin. Conclusions: It seems that antinocicptive effects of artemisinin are mediated by $GABA_A$ receptors.

Design of an Adaptive Backstepping Controller for Doubly-Fed Induction Machine Drives

Dehkordi, Behzad Mirzaeian,Payam, Amir Farrokh,Hashemnia, Mohammad Naser,Sul, Seung-Ki The Korean Institute of Power Electronics 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.3

In this paper, a nonlinear controller is proposed for Doubly-Fed Induction Machine (DFIM) drives. The nonlinear controller is designed based on an adaptive backstepping control technique, using a fifth order model of an induction machine in the synchronous d & q axis rotating reference frame, whose d axis coincides with the space voltage vector of the main AC supply, and using the rotor current and stator flux components as state variables. The nonlinear controller can perfectly track the torque reference signal measured in the stator terminals under the condition of unity power factor regulation, in spite of the stator and rotor resistance variations. In order to make the drive system capable of operating in the motoring and generating modes below and above the synchronous speed, two level Space-Vector PWM (SV-PWM) back-to-back voltage source inverters are employed in the rotor circuit. It is confirmed through computer simulation results that the proposed control approach is effective and valid.

Optimal Design of a Damped Input Filter Based on a Genetic Algorithm for an Electrolytic Capacitor-less Converter

Dehkordi, Behzad Mirzaeian,Yoo, Anno,Sul, Seung-Ki The Korean Institute of Power Electronics 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.3

In this paper an optimal damped input filter is designed based on a Genetic Algorithm (GA) for an electrolytic capacitor-less AC-AC converter. Sufficient passive damping and minimum losses in passive damping elements, minimization of the filter output impedance at the filter cut-off frequency, minimization of the DC-link voltage and input current fluctuations, and minimization of the filter costs are the main objectives in the multi-objective optimization of the input filter. The proposed filter has been validated experimentally using an induction motor drive system employing an electrolytic capacitor-less AC-AC converter.

SOME NEW CHARACTERIZATIONS OF QUASI-FROBENIUS RINGS BY USING PURE-INJECTIVITY

Moradzadeh-Dehkordi, Ali Korean Mathematical Society 2020 대한수학회보 Vol.57 No.2

A ring R is called right pure-injective if it is injective with respect to pure exact sequences. According to a well known result of L. Melkersson, every commutative Artinian ring is pure-injective, but the converse is not true, even if R is a commutative Noetherian local ring. In this paper, a series of conditions under which right pure-injective rings are either right Artinian rings or quasi-Frobenius rings are given. Also, some of our results extend previously known results for quasi-Frobenius rings.

Design of an Adaptive Backstepping Controller for Doubly-Fed Induction Machine Drives

Behzad Mirzaeian Dehkordi,Amir Farrokh Payam,Mohammad Naser Hashemnia,Seung-Ki Sul 전력전자학회 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.3

In this paper, a nonlinear controller is proposed for Doubly-Fed Induction Machine (DFIM) drives. The nonlinear controller is designed based on an adaptive backstepping control technique, using a fifth order model of an induction machine in the synchronous d & q axis rotating reference frame, whose d axis coincides with the space voltage vector of the main AC supply, and using the rotor current and stator flux components as state variables. The nonlinear controller can perfectly track the torque reference signal measured in the stator terminals under the condition of unity power factor regulation, in spite of the stator and rotor resistance variations. In order to make the drive system capable of operating in the motoring and generating modes below and above the synchronous speed, two level Space-Vector PWM (SV-PWM) back-to-back voltage source inverters are employed in the rotor circuit. It is confirmed through computer simulation results that the proposed control approach is effective and valid.

Mutations in GJB2 as Major Causes of Autosomal Recessive Non-Syndromic Hearing Loss: First Report of c.299-300delAT Mutation in Kurdish Population of Iran

Fatemeh Azadegan-Dehkordi,Tayyebe Bahrami,Maryam Shirzad,Gelareh Karbasi,Nasrin Yazdanpanahi,Effat Farrokhi,Mahbobeh Koohiyan,Mohammad Amin Tabatabaiefar,Morteza Hashemzadeh-Chaleshtori 대한청각학회 2019 Journal of Audiology & Otology Vol.23 No.1

Background and Objectives: Autosomal recessive non-syndromic hearing loss (ARNSHL)with genetic origin is common (1/2000 births). ARNSHL can be associated with mutations ingap junction protein beta 2 (GJB2). To this end, this cohort investigation aimed to find thecontribution of GJB2 gene mutations with the genotype-phenotype correlations in 45 ARNSHLcases in the Kurdish population. Subjects and Methods: Genomic DNA was extractedfrom a total of 45 ARNSHL families. The linkage analysis with 3 short tandem repeat markerslinked to GJB2 was performed on 45 ARNSHL families. Only 9 of these families werelinked to the DFNB1 locus. All the 45 families who took part were sequenced for confirmationlinkage analysis (to perform a large project). Results: A total of three different mutationswere determined. Two of which [c.35delG and c.-23+1G>A (IVS1+1G>A)] were previouslyreported but (c.299-300delAT) mutation was novel in the Kurdish population. The homozygouspathogenic mutations of GJB2 gene was observed in nine out of the 45 families(20%), also heterozygous genotype (c.35delG/N)+(c.-23+1G>A/c.-23+1G>A) were observedin 4/45 families (8.8%). The degree of hearing loss (HL) in patients with other mutationswas less severe than patients with c.35delG homozygous mutation (p<0.001). Conclusions:Our data suggest that GJB2 mutations constitute 20% of the etiology of ARNSHL inIran; moreover, the c.35delG mutation is the most common HL cause in the Kurdish population. Therefore, these mutations should be included in the molecular testing of HL in thispopulation.

The antinociceptive effect of artemisinin on the inflammatorypain and role of GABAergic and opioidergic systems

Faraz Mahdian Dehkordi,Jahangir Kaboutari,Morteza Zendehdel,Moosa Javdani 대한통증학회 2019 The Korean Journal of Pain Vol.32 No.3

Background: Pain is a complex mechanism which involves different systems, including the opioidergic and GABAergic systems. Due to the side effects of chemical analgesic agents, attention toward natural agents have been increased. Artemisinin is an herbal compound with widespread modern and traditional therapeutic indications, which its interaction with the GABAergic system and antinoniceptive effects on neuropathic pain have shown. Therefore, this study was designed to evaluate the antinociceptive effects of artemisinin during inflammatory pain and interaction with the GABAergic and opioidergic systems by using a writhing response test. Methods: On the whole, 198 adult male albino mice were used in 4 experiments, including 9 groups (n = 6) each with three replicates, by intraperitoneal (i.p.) administration of artemisinin (2.5, 5, and 10 mg/kg), nal-oxone (2 mg/kg), bicuculline (2 mg/kg), saclofen (2 mg/kg), indomethacin (5 mg/kg), and ethanol (10 mL/kg). Writhing test responses were induced by i.p. injection of 10 mL/kg of 0.6% acetic acid, and the percentage of writhing inhibition was recorded.Results: Results showed significant dose dependent anti-nociceptive effects from artemisinin which, at a 10 mg/kg dose, was statistically similar to indomethacin. Neither saclofen nor naloxone had antinociceptive effects and did not antagonize antinociceptive effects of artemisinin, whereas bicuculline significantly inhibited the antinocicptive effect of artemisinin. Conclusions: It seems that antinocicptive effects of artemisinin are mediated by GABAA receptors.

The investigation of the combined effects of gamma irradiation and environmental manipulation on mortality and sterility of Rhyzopertha dominica (Fabricius) (Coleoptera: Bostrichidae)

Shohreh Asgarian Dehkordi,Mehrdad Ahmadi,BijanHatami 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.4

With respect to the limitations use of methyl bromide and phosphine, employing ionizing radiation to control stored product pests has attracted great attention. The aim of this study is the investigation of the combined effects of gamma irradiation as viable alternatives to synthetic insecticides and environmental management on mortality and sterility of Rhyzopertha dominica (Fabricius) in a wheat cultivar (Gascogen). The effect of doses range from 30 to 2000 Gy gamma irradiation in combination with manipulation of temperature (15, 21, 27 and 32 °C) and relative humidity (20%, 50%, 65% and 85%) on 5–10 days old adults of R. dominica in Gascogen cultivar of wheat were explored. The experiments were repeated three times and conducted in The Nuclear Agriculture Research School in Karaj and laboratory of shahid steki silo in shahre-kord. Probit analysis revealed that both temperature and relative humidity had combined effects when used with gamma irradiation. The lowest doses of gamma ray required to kill 25% (14.2 Gy) and 50% (610.8 Gy) of the population (LD 25 and LD 50 ) were recorded at 21 °C and 85% relative humidity respectively. The low dose for 99% mortality (LD 99 ; 2386.7 Gy) was recorded for beetles maintained at 21 °C and 50% relative humidity. The effect of temperature (15, 21, 27 and 32 °C) on sterility caused by gamma irradiation was also investigated. The results showed that the F 1 generation emerged only when the beetles were treated with doses of 0–100 Gy at 32 °C and 0–70 Gy at 27 °C. These results indicate that temperature and relative humidity play an important role in the susceptibility of the lesser grain beetle to gamma irradiation. The results suggest that controlling the efficiency of gamma radiation through environmental control allows the use of low doses of gamma radiation that have a less harmful effect on human health, non-target organisms and seed agronomic features.