A 6-kVA three-phase model of the flux transfer-type current-limiting transformer was developed and tested. In this device, the winding loops of YBCO superconducting tapes couple magnetically two ...independent iron cores: the primary-side iron core and the secondary-side iron core. The former and the latter are equipped with copper primary and secondary windings, respectively. Because the magnetic fluxes linked to the superconducting winding loops must be kept constant, the magnetic flux is transferred by the superconducting YBCO loops between the two iron cores in order to couple magnetically the primary and secondary coils. While the YBCO loops are superconducting, 100 % of the magnetic flux is transferred and the device shows the similar function as usual transformers. Once the YBCO loops become normal by a fault current in any of the windings, the power transfer between two iron cores is limited and the current in the secondary winding is limited naturally on a result of decoupling the iron cores.
We present two cases of cardiac sarcoidosis whose first presentation was in pregnancy. All findings confirmed the diagnosis of sarcoidosis with cardiac involvement in both patients. The first ...patient, a 37-year-old, presented with dizziness and atrial fibrillation at 16 weeks' gestation. Echocardiography revealed thickened interventricular septum with a speckled pattern. Cardiac MRI after delivery showed myocardial oedema/inflammation corresponding with the same regions with early enhancement and epicardial delayed enhancement in the basal to mid-inferoseptal and basal anterior left ventricular myocardial segments. Transbronchial biopsy revealed histology of scanty fragments of inflamed bronchial mucosa. The second patient, a 31-year-old, was 17 weeks pregnant when she presented with daily palpitations and shortness of breath. She had prolonged episodes of supraventricular tachycardia. Echocardiography revealed a speckled septal and right ventricular wall pattern. Cardiac MRI after delivery showed basal and mid-ventricular mesocardial and epicardial enhancement, most compatible with sarcoidosis.
United States Department of Defense (DoD) Services (e.g., Army, Navy, Air Force) deploy different network devices in their enclave networks. These devices provide edge network functions such as ...information assurance, plain text routing, admission and congestion control, and TCP performance enhancements. Due to the different enclave network implementations in different Service networks, interoperability issues arise when connecting enclave networks between different Services. This paper describes tactical user enclave network implementations within the DoD's Global Information Grid, and how these networks currently achieve interoperable connectivity by backhauling traffic to fixed gateways connected to the Defense Information Systems Network (DISN) core. This paper examines three gateway options, including a cipher text gateway, a plain text gateway, and a Joint plain text gateway for providing interoperable inter-Service connectivity within the tactical environment. We provide qualitative comparisons of these architecture options and provide recommendations for their use in creating an interoperable tactical architecture.
The Department is increasingly relying on IP multicast to support a growing demand for disseminating intelligence, surveillance, and reconnaissance (ISR) and to maximize bandwidth savings across ...strategic and resource-constrained tactical edge networks. A number of operational communities, including Global Broadcast Service (GBS), US Central Command (CENTCOM) Digital Video Broadcast - Return Channel Service (DVB-RCS), Unified Video Dissemination Service (UVDS), the Joint Communications Support Element (JCSE), Deployable Joint Command and Control (DJC2), Army (through its WIN-T program), and Missile Defense Agency (MDA) are currently using or planning the deployment of multicast across their networks. This paper will first discuss a short-term architecture for deploying IP multicast associated with the dissemination of UVDS, GBS, and DVB-RCS video streams to tactical users. This design involves the configuration of multicast Rendezvous Points (RPs) at strategic locations, combined with IPsec VPNs (used for transporting multicast across the Defense Information Systems Network (DISN)) to disseminate multicast traffic between fixed/tactical sources and receivers. Although this short-term solution will yield considerable benefits, it exhibits shortcomings that result from the lack of a common/standardized enterprise-wide multicast approach-programs are independently developing their own multicast architectures, leading to designs that are not scalable, interoperable, or efficient and require much more engineering to implement in an enterprise environment. A key component of this enterprise multicast architecture is the enabling of native multicast services across the DISN. A DISN multicast service, coupled with the enabling of multicast across DoD Gateways, Defense Enterprise Computing Centers (DECCs), Base / Camp / Post / Stations (B/C/P/S), and Deployed Networks (DNs), allows a standardized approach for subscription of these services, reduces engineering time to stand-up program specific multicast solutions, and increases the overall scalability and efficiency of traffic distribution. This paper will present the enterprise-wide multicast architecture and explain how the native enterprise multicast service will benefit existing and future strategic and tactical users. Lessons learned and implementation guidance, produced as part of several multicast Modeling and Simulation (M&S) and testing efforts throughout DISA, will be conveyed.
Similar to the customer / service provider network model that exists in the Internet today, the Department of Defense's (DoD's) Global Information Grid (GIG) will consist of various customer networks ...(Army, Navy, etc.) that interconnect over a common core. Customer networks will source and sink IP traffic, and a transit network(s) will provide connectivity between geographically disparate customer networks. As networks within the GIG begin to transition from the Internet Protocol version 4 (IPv4) to IPv6, three different types of networks will emerge: IPv6-only, IPv4-only, and dual-stack (IPv4 and IPv6). These three network types will appear in both GIG customer networks and transit networks. Interconnecting hosts across these heterogeneous networks presents various routing and forwarding challenges. For example, a transit network that supports a single address family (e.g., IPv6) cannot forward packets for customers that are of a different address family (e.g., IPv4). Therefore, a mechanism that allows the transit network to forward an unsupported address family is needed. This paper reviews new mechanisms that are being developed in the Internet Engineering Task Force (IETF) Softwires Working Group (WG) and proposes to leverage these mechanisms to solve several GIG routing problems. Applied to the GIG, a softwire-based architecture can be used by IPv6-only core networks to transport customer IPv4 traffic, and IPv4-only core networks to transport customer IPv6 traffic. In addition, the application of softwires to enable "prefix tracking" for IP security (IPsec)-protected encInternet Engineering Task Force (IETF) Softwires Working Grouplaves is discussed.
