High Capacity Channel Research Articles

Modulation Method for High-Capacity Fibre Channel Switch and High-Speed Pulse Network Data

Fibre channel (FC) switches are widely used in storage area networks and avionics systems. In this work, the FC protocol, the switching structure and the scheduling algorithm of the FC switch are deeply studied, and a 48-port FC switch is completed on a single-chip field-programmable gate array (FPGA). In addition, an improved scheduling algorithm for Inter-System Link Protocol (iSLP) is proposed for the input and scheduling of optical fiber pulse network data. On this basis, the overall architecture of the FC switch is proposed, the x690tffg1158 FPGA chip is selected, and the FC port control module is designed, which is composed of the receiving controller, the interface state machine, the sending controller, and the flow control. The routing table lookup module of FC switch is designed, the unicast routing table format and multicast routing table format are proposed, and the corresponding unicast and multicast routing table lookup table module architectures are designed. Aiming at the characteristics of high reliability and low distortion in the transmission of high-speed pulse network signals by FC switches, the modulation and demodulation of Bias-T (BIAS-T) are redesigned. The experiment is implemented using Verilog hardware description language (HDL), and Modelsim 10.5 software is adopted to simulate each module of the switch. The switch adopts an 8×N switching structure, which can accurately perform word synchronization. After the link is initialized, the transceivers can send and receive data frames normally. The redesigned BIAS-T is applied to solve the instability of the end of the analog modulation method, and then realize the low distortion and data integrity of the high-speed pulse signal of the FC switch.

CLIMATE CHANGES AND SITE DISPOSAL OF OBJECTS ON THE CHRONOBYL STATION SITE

Currently, in the Exclusion Zone at the site of the Chornobyl NPP, work is being carried out on the final closure and conservation of power units 1–3, the feature of which is the presence of a high-capacity channel uranium-graphite reactor (RVPK). During operation, the reactor graphite becomes radioactive due to the accumulation of the long-lived radionuclide 14C in the graphite. An additional contribution is made by the indicated radioactivity of technological impurities (36Cl, 60Co) and spills of fission products and fragments of nuclear fuel. The main problem of the decommissioning of nuclear installations from the RVPK is related to the need to choose optimal methods of handling large volumes of spent graphite. The possibility of applying the technology of near-surface disposal of decommissioned uranium-graphite reactors of the RVPK, known as the “green mound”, to power units 1–3 of the Chernobyl NPP was considered. Natural factors have been identified, the possible action of which during the time required for the decay of radionuclides 14C and 36Cl to an acceptable level, may lead to the destruction of near-surface storage facilities for disposal at the Chernobyl NPP site. These factors determine the rehabilitation of the river valley of the Pripyat River and the vulnerability of surface disposal repositories to the effects of cyclical climate changes. Climatic changes should be taken into account when making decisions on on-site disposal, given that the processes of decay of long-lived radionuclides, degradation of matrices of incorporated radioactive waste, and the duration of protective barriers in terms of time are relevant to the dynamics of climate change. The need to take into account the impact of global climate changes on the intensity of changes in the geomorphological characteristics of the locations of “green mounds” was noted. A particularly dangerous and powerful natural factor that will inevitably lead to the destruction of the “green mounds” is the influence of probable glaciation. The relevance of solving the scientific task of a complex combination of knowledge regarding the formation of the physical and geographical features of Polissia in the last 200 thousand years with the modeling of climate changes in the future 100 thousand years is emphasized, which will allow to reasonably accept or reject the very idea of near-surface burial of long-lived radioactive waste at the Chernobyl NPP site.

Performance improvement of space diversity technique using space time block coding for time varying channels in wireless environment

Performance improvement of space diversity technique using space time block coding for time varying channels in wireless environment

Stochastic models of multi-channel particulate transport with blockage

Particle conveying channels may be bundled together. The limited carrying capacity of the constituent channels may cause the bundle to be subject to blockages. If coupled, the blockage of one channel causes an increase in the flux entering the others, leading to a cascade of failures. Once all the channels are blocked, no additional particles may enter the system. If the blockages are of finite duration, the system reaches a steady state with an exiting flux that is reduced compared to the incoming one. We propose a stochastic model consisting of Nc channels, each with a blocking threshold of N particles. Particles enter the system’s open channels according to a Poisson process, with an equally distributed input flux of intensity Λ. In an open channel the leading particle exits at a rate μ and a blocked channel unblocks at a rate , where . We present and explain the methodology of an analytical description of the behavior of bundled channels. This leads to exact expressions for the steady-state output flux, for , which promises to extend to arbitrary Nc and N. The results are applied to compare the efficiency of conveying a particulate stream of intensity Λ using a single, high capacity (HC) channel with multiple channels of a proportionately reduced low capacity (LC). The HC channel is more efficient at low input intensities, while the multiple LC channels have a higher throughput at high intensities. We also compare coupled channels, each of capacity N = 2 with the corresponding number of independent channels of the same capacity. For , if , the coupled channels are always more efficient. Otherwise the independent channels are more efficient for sufficiently large Λ.

Microscopic Flow Characteristics of Fluids in Porous Medium and Its Relationship with Remaining Oil Distribution: A Case Study in Saertu Oilfield of Daqing in China

The Saertu Oilfield of Daqing in northeast China has entered ultrahigh water-cut stage of development. Numerical simulation is applied in this paper to study characteristics of microscopic fluid velocity and flow pressures variation in the core pores in the Beier Area of Saertu Oilfield. The relationship between the remaining oil distribution and microscopic flow characteristics of fluid in the pores has been analyzed. Study results show that, in the reservoir with stronger heterogeneity of grain size and throat (corresponding to high coordinate number), high flow velocities tend to occur in relatively wider pore throats with great differentiation of flow velocities. The dominant passages are developed in high capacity channel, the detour flows are created in large porous channels, and the isolated islands are formed in small porous channels. The flow velocity declines slowly with long duration of high pressure. Few pores are swept by injected fluids with low sweep efficiency. The microscopic remaining oil is mainly distributed in cluster state. The content of remaining oil is higher with lower oil displacement efficiency. By contrast, in the reservoir with weaker heterogeneity of grain size and throat (corresponding to low coordinate number), high flow velocities also develop in relatively narrower pore throats with little differentiation of flow velocities. The development of detour flows is weaker in large porous channels. The flow velocity declines quickly with a short duration of high pressure. More pores are swept by fluids with high sweep efficiency. The remaining oil is mainly distributed in state of thin film on pore surface. The content of remaining oil is lower with higher oil displacement efficiency.

The Hot Water Oil Expulsion Technique for Geothermal Resources

With the rapid development of Chinese petroleum industry, Oil production way of burning crude oil to produce steam need change. Heavy oil reservoir with thin layer or edgewater is unsuitable thermal recovery, electric heating leads to considerable electrical consumption, low injection water temperature decreases reservoir temperature and increased crude oil viscosity. The prolonged temperature difference break up reservoir pore throat cement and framework minerals. To improve high-capacity channel communication, we proposed geothermal oil recovery. Broad-sense abundant geothermal resources and existing injection water technique equipment are used, deep-seated high temperature liquid (oil-gas-water mixture) draws geothermal warming flowing layer to transit heat upward, decreases viscidity and increases fluidity. Reservoir temperature different offer geothermal fountain. Practicability process is analyzed. statistics and reservoir temperature variation analysis of Gudong Oilfield, Shengli Oilfield Company, SINOPEC, we have designed flow-chart concept for geothermal oil recovery, suggested drilling multi-branch well in heavy oil reservoir as injection-well, at the same position of geothermal fountain well, using free-pressure pump to inject hot liquid directly to aimed oil layer, made oil recovery in surrounding wells. It is proposed that geothermal oil recovery forerunner test should be first conducted in favorable blocks.

Experimental Research of Applicability Condition for Foam Flooding

A series of experiments were conducted according the formation condition of Bohai Oilfield, and applicability conditions and optimum parameters were gained. From economic considerations, foam injection volume should be from 0.3 to 0.5 PV. Applicable permeability ratio range of foam flooding is less than 15. When permeability variation coefficient is from 0.64 to 0.72, oil recovery improvement is the highest. When water cut of produced fluid for water flooding is from 80 % to 90 %, the effect of foam injection is the best. The blocking effect of foam in core is good for gas liquid ratio from 0.5 to 2.5. Considering gas crossflow, gas water ratio should be limited from 0.5 to 1.0. Slug injection is better than continuous and SAG injection methods. If there is high-permeable layer or high capacity channel with permeability higher than 10 D, deep blankoff using blocking agent should be implemented before foam injection.

Simulation of an Optical Buffer using Microring Resonator Array with 1.5 μm Radius

We present the design and FDTD simulations of microring resonator array optical buffer. The proposed buffer consists of six microring array coupled via upper MZI arm, and one microring is coupled via the lower MZI arm, where all coupling gap used is with 105nm. Results obtained have shown that the delay times of the output signals can be used to form the optical buffer(memory), which can be available for high capacity channel multiplexing and filtering applications.

Design for WDM rings based on differentiated path availability

In this paper, we consider the problem of traffic grooming in optical wavelength division multiplexed (WDM) mesh networks under dynamic traffic conditions. Grooming can be done at each node by using electronic SONET add-drop multiplexers (SADMs) to multiplex several low-rate connections on to the high-capacity wavelength channel, and provision them as a single lightpath. However, SADMs are costly devices and it is expensive to equip each port and wavelength in every node with grooming capabilities. This leads to the concept of limited grooming that uses fewer SADMs at the nodes: only a subset of the ports and wavelengths are equipped with SADMs. The paper presents a systematic performance evaluation of a limited grooming optical network supporting dynamic traffic requests. Four different limited grooming node architectures and related grooming policies are presented. We consider the effect of several important factors including: connection granularity, traffic grooming policy, number of grooming ports per node, grooming port tunability, and wavelength conversion. Simulation results indicate that limited grooming at each node is sufficient to obtain the performance obtained with full grooming, especially when connections occupy a small fraction of the wavelength capacity. Further, the connection granularity, the grooming policy and the number of wavelengths used per link for a connection are also seen to have a significant effect on the performance. The tunability of the SADMs and the port-sharing architecture are not seen to have a significant impact on the performance.

Millimeter-Wave High-Speed Spot Communication System Using Radio-Over-Fiber Technology

We developed Millimeter-wave high speed spot communication system using radio-over-fiber technology for ITS telecommunication use. This system has wide bandwidth and provides a high-capacity channel between the base station and parked vehicles. The installation conditions (height, elevation angle) of the base station antenna of this system that enabled the largest possible communication area were obtained by simulation. In addition, we measured propagation and transmission characteristics. The width of the error-free service area was 8 m, which enables three vehicles to be served in one service area.

A Unified Mechanism for Multimedia Downlink Scheduling and Call Admission Control for Future Error-Prone Wireless Networks

In this paper we design and evaluate the performance of a unified mechanism for downlink scheduling and call admission control of multimedia traffic in a high-capacity TDMA wireless channel. In our scheme, the Base Station interacts with the Call Admission Controller and incorporates predictions on the channel condition in its decision making. Our results show that, with the use of the "intelligent" scheduler-admission controller mechanism, system performance is significantly enhanced compared to two other schemes without prediction on the channel condition.

Delay analysis of a dual-bus LAN with reservation

A dual-bus token passing protocol with reservation is introduced and analysed in this paper. To provide different services in the dual-bus network, one of the buses is used to serve synchronous packets and the other is used to serve asynchronous packets. We use a small amount of the bandwidth of the synchronous channel to enable the token on the asynchronous channel being dynamically passed to ready users, thus the waiting time on the asynchronous channel is greatly reduced. This protocol is especially suitable for dual-bus networks whose channel capacity difference is large. With negligible overhead of the high capacity channel, improvement in waiting time along the low capacity channel can be drastic. The results of this study demonstrate that the protocol offers a substantial improvement in the waiting time on the asynchronous channel, while the trade-off is just a little increased bandwidth in the synchronous channel. Analytical results of this reservation scheme show excellent agreement with computer simulated results when the capacities of the two buses are 10 Mbit/s and 1 Mbit/s, respectively.

Performance and Operation of a Crosslinked Polymer Flood at Sage Spring Creek Unit A, Natrona County, Wyoming

Summary This paper reviews field geology and development, characterizes the reservoir, evaluates secondary performance, and describes the design and benefits of a performance, and describes the design and benefits of a polymer program. Performance of the Sage Spring Creek polymer program. Performance of the Sage Spring Creek Unit A confirms a high flood efficiency and superior oil recovery. The sweep improvement program is a technical and economic success. Introduction The Sage Spring Creek Unit A was discovered in 1949 and produces from a fractured Dakota sandstone. The field was under fluid-expansion/solution-gas-drive primary recovery until a five-injection-well peripheral primary recovery until a five-injection-well peripheral waterflood began in 1972. Injection rates were low to establish a flood front and to prevent channeling. In 1978, a volumetric sweep program was initiated in three injection wells to divert injection into the lower-permeability rock. Cationic and anionic polymers and aluminum citrate were injected to provide in-depth diversion of injection water. Field Discovery The Sage Spring Creek Unit is located in Natrona County (WY) approximately 25 miles [40 km] northeast of Casper. The field makes up part of the first line of folding along the southwestern margin of the Powder River basin. It lies 10 to 15 miles [16 to 24 km] south of the prolific Salt Creek and Teapot (U.S. Naval Reserve) fields. The discovery well, Amerada 1, was drilled by Amerada Hess Corp. to a total depth of 9,539 ft [2908 m] in Aug. 1949, plugged back, and completed in the Dakota sandstone at 7,200 ft [2195 m], and pumped 68 B/D [10.8 m3/d] oil. Ten producing wells were drilled between discovery and May 1954. No further development took place until 1971, when Farmers Union Exchange (Cenex) purchased the property. Geological and Reservoir Characteristics From Ref. 1: "The Sage Spring Creek Unit lies on the Sage Spring Creek anticline, a surface structure, which is a south-plunging nose with no north closure. The anticline plunges southward two degrees and dips on the east and west. Flanks of the structure average about seven degrees. Structural relief from the south end of the Unit to the north end amounts to about 2,800 feet (853.4 m). No faulting has been noted on this structure."The only producing horizon within the Unit is the Dakota sandstone. Oil is trapped as a result of changes in porosity and permeability of the Dakota sandstone in an porosity and permeability of the Dakota sandstone in an updip direction. The Dakota sandstone is Lower Cretaceous in age and present throughout the southwestern Powder River basin. The sandstone varies in amounts of siltstone and shale and is related to shoreline environment. The clean, well-developed sands are probably channel or offshore bar-type deposits, while the tight sand/siltstone/shale facies are deeper-water accumulations. The areal extent and well location of the Sage Spring Creek Unit A is shown in Fig. 1. The reservoir limits are defined on the southwest edge by an oil/water contact and to the north and east by a pinchout of permeability and porosity. The reservoir covers a total surface area of 1,456 acres [5892 × 103 m2] with an average net pay thickness of 21.6 ft [6.6 m]. The total volume of the oil zone is 31,487 acre-ft [38 839 × 103 m3]. The reservoir is split into two areas: a high-capacity channel and a low-capacity area. The high-capacity channel lies along the southwestern edge of the reservoir and trends from the southeast to the northwest. Air permeabilities range from 1 to 281 md, giving a permeabilities range from 1 to 281 md, giving a Dykstra-Parsons permeability variation of 0.82. Some fracturing may exist in the high-capacity channel with directional permeability and fracture orientation parallel to the permeability and fracture orientation parallel to the channel. The low-capacity area is located in the northeastern portion of the reservoir and exhibits much lower portion of the reservoir and exhibits much lower permeability. Production capacity is limited in this area permeability. Production capacity is limited in this area of the field. The combination of permeability variation and fracturing makes the reservoir very heterogeneous. Produced oil from the Dakota sandstone is 36 deg. API [0.84-g/cm3] sweet crude. The viscosity of the oil at reservoir temperature (160 deg. F [71 deg. C]) is near 1.0 cp [0.001 Pas], giving a favorable water/oil mobility ratio. Average reservoir porosity is 13% and connate water saturation is 25%. Original oil in place (OOIP) is 630 STB/acre-ft or 19,800,000 STB [3148 × 103 stock-tank m3]. Reservoir and fluid properties are presented in Table 1. Primary Performance Primary Performance The primary producing mechanism was solution gas drive with a partial edgewater drive. JPT P. 1145

The 3B20D Processor & DMERT Operating System: 3B20D File Memory Systems

The 3B20D file memory system employs microprocessor-based intelligent Disk File Controllers (DFC), each supporting a complement of one to eight 300-megabyte disk drives. The DFC communicates with the system via a high-capacity dual-serial channel link to the Direct Memory Access Controller (DMAC) that accesses the processor's main memory. The DFC communicates with its disk files via an industry standard interface. The disk power system is also microprocessor based. The system operates disk drives on commercial ac power until a power failure occurs. The disks are then switched under microprocessor control to inverter power until the commercial ac fault is cleared, at which time the disk is returned to commercial ac power.