28 research outputs found
Some results on relative dual Baer property
Let be a ring. In this article, we introduce and study relative dual Baer property. We characterize -modules which are -dual Baer, where is a commutative principal ideal domain. It is shown that over a right noetherian right hereditary ring , an -module is -dual Baer for all -modules if and only if is an injective -module. It is also shown that for -modules , , , such that is -projective for all i > j \in \{1,2,\ldots, n\}, an -module is -dual Baer if and only if is -dual Baer for all . We prove that an -module is dual Baer if and only if is a Baer ring and for every right ideal of
Rad-supplements in injective modules
We introduce and study the notion of Rad-sinjective modules (i.e. modules which are Rad-supplements in their injective hulls). We compare this notion with another generalization of injective modules. We show that the class of Rad-s-injective modules is closed under finite direct sums. We characterize Rads-injective modules over several type of rings, including semilocal rings, left hereditary rings and left Harada rings. © Journal “Algebra and Discrete Mathematics”
Some rings for which the cosingular submodule of every module is a direct summand
The submodule Z(M) = ∩{N | M/N is small in its injective hull} was introduced by Talebi and Vanaja
in 2002. A ring R is said to have property (P ) if Z(M) is a direct summand of M for every R-module M . It is
shown that a commutative perfect ring R has (P ) if and only if R is semisimple. An example is given to show that
this characterization is not true for noncommutative rings. We prove that if R is a commutative ring such that the class
{M ∈ Mod−R | ZR(M) = 0} is closed under factor modules, then R has (P ) if and only if the ring R is von Neumann
regular
A novel coplanar slot antenna structure for wireless applications
This paper presents a new compact broadband coplanar slot antenna for multiple wireless communication applications which include WIMAX, RFID, WLAN and ISM bands. The antenna structure is based on the CPW-fed combined with a slot technique and a modified geometry antenna in order to enlarge the bandwidth. The antenna parameters have been investigated and optimized by using Momentum software integrated into ADS” Advanced Design System” from Agilent Technologies with a comparison of the results using another simulator CST Microwave Studio. The measured input impedance bandwidth, ranging from 2.15GHz to 4.4GHz, is obtained with a return loss less than - 10dB, corresponding to 66.7% at 3.27GHz as a center frequency. The design considerations for achieving broadband antenna and both experimental, simulated results are presented
A new compact and miniaturized GCPW-fed slotted rectangular antenna for wideband UHF FIRD applications
This paper presents the development of a new miniaturized and compact GCPW-fed slotted rectangular antenna structure reader for wideband UHF RFID applications. The optimized proposed antenna is suitable to operate a large frequency-band range from 0.8GHz to 1.3GHz with a bandwidth of 500MHz with a return loss less than -10dB. The antenna is based on a 1.6mm thickness FR4 epoxy substrate with a reduce dimensions compared to the simple rectangular antenna and size of proposed antenna is 47*40mm2. The new design consists of a compact rectangular patch with symmetric U-shaped slots and I-shaped include a partial ground plan and fed by 50 Grounded coplanar line. The antenna parameters have been investigated and optimized by using CST Microwave Studio. To validate the CST Microwave Studio results before the antenna achievement, we have conducted another study by using ADS. The final circuit achieved, measured and validated. Experimental results show that the proposed antenna has good radiation characteristics and operating in UHF-RFID applications
New compact antenna structures with a slot shaped and a stub tuning for ultra wide band applications
This paper presents the design of new compact printed broadband antennas for Ultra Wide Band applications. The antenna structures are based on the CPW-fed combined with a slot and a stub line to increase the bandwidth. The proposed antennas have been successfully designed, optimized and simulated by using Momentum software integrated into ADS "Advanced Design System" and CST Microwave Studio. The measured input impedance bandwidth of the final broadband antennas ranging from 2.1-7.3 GHz and 2.1-11 GHz. The design considerations for achieving broadband antennas and both simulated, experimental results are presented and discussed
A new compact printed antenna structure for multiple wideband applications
This paper presents the design of a new compact antenna structure for multiple incorporating operation service. The proposed antenna is suitable to operate at three different frequency bands, (1.77GHz-2.67GHz), (3.1GHz- 4.58GHz), and (5.5GHz-6.5GHz) with a return loss less than -10dB. The antenna structure includes a CPW fed line, the technique used to enlarge the frequency bands is the slots technique and in the same time we have developed a new antenna structure which operates in various wireless communication applications. The antenna parameters have been investigated and optimized by using CST Microwave Studio. To validate the CST Microwave Studio results before the antenna achievement, we have conducted another study by using ADS. The final circuit was achieved, measured and validated. Experimental results show that the proposed antenna with compact size of 42*32.7 mm2 has good radiation characteristics and operating in specific microwave applications ISM band, WLAN, WIFI, WIMAX and RFID
Design of a New Compact Printed MonopoleAntenna by using Tuning Stub for UWB Applications
Wideband applications put a new demand on antennas pertaining to size, gain, efficiency, bandwidth and more. This paper presents the design and analysis of a new compact broadband coplanar slot antenna for multiple wireless communication applications. The antenna structure is based on the CPW-fed combined with slot technique, stub tuning and a modified geometry antenna in order to enlarge the bandwidth. The antenna parameters have been investigated and optimized by using CST Microwave Studio with a comparison of the results by using another simulator ADS” Advanced Design System from Agilent Technologies. The simulated input impedance bandwidth, ranging from 8GHz to 23GHz, is obtained with a return loss less than -10dB, corresponding to 96.77% at 15.5GHz as a center frequency. Details of the proposed antenna design and simulated results are described and discussed
Finitely genarated -supplemented modules are amply -supplemented
It is shown that if a module is a sum of -local submodules and a semisimple projective submodule, then every finitely generated submodule
of is -supplemented. From this result, we conclude that finitely generated -supplemented modules over commutative rings
are amply -supplemented.
10.1017/S000497271100340