Search

An integral domain D, with quotient field K, is a v-domain if for each nonzero finitely generated ideal A of D we have (A A − 1) − 1 = D. It is well known that if D is a v-domain, then some quotient ring DS of D may not be a v-domain. Calling D a super v-domain if every quotient ring of D is a v-domain we characterize super v-domains as locally v-domains. Using techniques from factorization theory we show that D is a super v-domain if and only if D [ X ] is a super v-domain if and only if D + X K [ X ] is a super v-domain and give new examples of super v-domains that are strictly between v-domains and P-domains, domains that are essential along with all their quotient rings. [ABSTRACT FROM AUTHOR]

In this paper the design of 8-channel Dense wavelength division multiplexing (DWDM) chaotic system is presented at frequencies ranging from 193.0 TIIz to 193.7 Thz. The chaotic signals are generated by. using semiconductor laser and mathematically modeled by laser rate equation. The Gain flattening! filter (OFF) is used with Erbium doped fiber amplifier (EDFA) in DWDM communication model for long distance transmission. The optimization of Gain| flattening filter is done in chaotic environment to achieve the flattened gain profile of EDFA. The synchronization of chaos at transmitter and receiver is| achieved to recover the received signal. Thus, our scheme combines two advantages i.e. efficient bandwidth utilization and security at the same time inj DWDM communication model. [ABSTRACT FROM AUTHOR]

In this research paper comparison of efficient binary modulation formats like Chirped-NRZ, Chirped-RZ, RZ-50%, Duobinary and AMI is carried out for GPON networks. Their performance is evaluated in terms of bit rates versus fiber link length. Chirped-NRZ comes out to be optimal modulation format for high speed and long reach optical communication. Quality of the received signal is analyzed by considering parameters like Q-factor and BER. Three different data rates i.e. 10 Gbps, 40 Gbps and 100 Gbps are selected to evaluate the performance of optical communication system whereas optical fiber length is varied from 40 km to 140 km. Simulations are performed on licensed version of Optisystem v.14. [ABSTRACT FROM AUTHOR]

Vehicular ad-hoc network faces many challenges, in particular frequent handoffs due to high mobility of vehicles is a serious performance limitation factor and is probably the most critical process in terms of packet loss and delay. In this paper an efficient mechanism of Vehicular Ad-hoc Networks (VANETs) is proposed for making handoff decision that considers both Received Signal Strength (RSS) and Global Positioning System (GPS) information along with maps. Furthermore; the proposed mechanism focuses on nodes moving at high speeds while receiving and saving the relevant information in buffers. This particular approach not only minimizes delay and packet loss but is also used to retransmit the lost packets locally. The addition of this capability in the proposed mechanism contributes in improving the packet loss in less crowded areas having limited available connectivity. [ABSTRACT FROM AUTHOR]

An integral domain D is called a locally GCD domain if DM is a GCD domain for every maximal ideal M of D. We study some ringtheoretic properties of locally GCD domains. For example, we show that D is a locally GCD domain if and only if aD ∩ bD is locally principal for all 0 ≠ a; b ∈ D, and at overrings of a locally GCD domain are locally GCD.We also show that the t-class group of a locally GCD domain is just its Picard group. We study when a locally GCD domain is Prüfer or a generalized GCD domain. We also characterize locally factorial domains as domains D whose minimal prime ideals of a nonzero principal ideal are locally principal and discuss conditions that make them Krull domains. We use the D + XDS[X] construction to give some interesting ex- amples of locally GCD domains that are not GCD domains. [ABSTRACT FROM AUTHOR]