Today's Capacity Research Articles

Group Key Management Protocols for Non-Network: A Survey

The phenomenal rise of the Internet in recent years, as well as the expansion of capacity in today's networks, have provided both inspiration and incentive for the development of new services that combine phone, video, and text "over IP." Although unicast communications have been prevalent in the past, there is an increasing demand for multicast communications from both Internet Service Providers (ISPs) and content or media providers and distributors. Indeed, multicasting is increasingly being used as a green verbal exchange mechanism for institution-oriented programmers on the Internet, such as video conferencing, interactive college games, video on demand (VoD), TV over the Internet, e-learning, software programme updates, database replication, and broadcasting inventory charges. However, the lack of security within the multicast verbal exchange model prevents the effective and large-scale adoption of such important company multi-celebration activities. This situation prompted a slew of research projects that addressed a variety of issues related to multicast security, including confidentiality, authentication, watermarking, and access control. These issues should be viewed within the context of the safety regulations that work in the specific conditions. For example, in a public inventory charge broadcast, while identification is a vital necessity, secrecy is not. In contrast, video-convention programme requires both identification and confidentiality. This study gives a complete examination and comparison of the issues of group key management. Both network-dependent and network-independent approaches are used. The study also addresses the advantages, disadvantages, and security problems of various protocols.

Analysis of Flow Patterns in High‐Gravity Equipment Using Gamma‐Ray Computed Tomography

AbstractThe capacity of today's gas‐liquid contacting equipment such as tray or packed columns is limited by the gravitational‐driven liquid flow. Intensified equipment applying centrifugal force offers great potential for enhancing the mass transfer and for reducing equipment size. Yet, detailed knowledge about the liquid flow inside rotating packings is scarce due to limited accessibility with conventional measurement systems. In this study, a gamma‐ray computed tomography is employed to quantify the liquid hold‐up and its distribution in the moving packing.

Big Data: An incoming challenge for vehicular ad‐hoc networking

Big Data is gaining lots of attentions from various research communities as massive data are becoming real issues, and processing such data is now possible thanks to available high‐computation capacity of today's equipment. This paper focuses especially on the network community where currently huge amount of data have to be processed in real time. In the meanwhile, it is also the beginning of vehicular ad‐hoc networking (VANET) era. Connected vehicles are being manufactured and will become an important part of vehicle market. Topology in this type of network is in constant evolution, accompanied by massive data coming from increasing volume of connected vehicles in the network. Therefore, we will handle this interesting topic by providing backgrounds on Big Data concerning vehicular networks. Key aspects of Big Data related to VANET (eg, data generation, preprocessing, and communication) are discussed. Finally, we will also illustrate how to analyze data in VANET by presenting a real experimentation and some representatives results.

Preparation of carbon cloth supported Sn thin film for structural lithium-ion battery anodes

Commercial carbon fibers have been studied in structural lithium-ion batteries (SLIBs) with good promises. However, the currently urgent issue is the limitation in capacity in today's SLIBs. In this work, we focus on fabrication of integrated Sn/carbon cloth (Sn/CC) composite with Sn nanoparticles uniformly coated onto the surface of the CCs with close connection between them. Due to the combined superiority of the Sn with high theoretical specific capacity and the carbon cloth with good conductivity and buffer effect, the prepared Sn/CC composite are expected to be employed as an anode material for future SLIBs. As a result, even though in high mass loading up to 5.19 mg cm−2, a high reversible capacity of 2.23 mAh cm−2 (i.e. 431.5 mAh g−1) is maintained over 100 cycles at a current density of 100 mA cm−2, showing a huge increase almost 3.3 times as high as the reported carbon fibers in SLIBs. Furthermore, even at a high current density of 2000 mA cm−2, the discharge capacity can still reach to 1.18 mAh cm−2. These good electrochemical performances in capacity could urgently solve the current issue that the limitation of capacity in current SLIBs when using commercial carbon fibers as anode materials.

A complexity perspective on collaborative decision making in organizations: The ecology of group-performance

Networks of communication are essential when managing corporate work and performing information exchange; the systems must allow them to be dynamic and well-structured. They help provide high organizational performance and innovative capacity in today's knowledge intense corporations, and this means that organizations must manage the networks strategically. Despite the fact that practitioners are aware of the huge influence of informal communication on decision making, little is known about the underlying principles of efficient employee network collaboration, which is dynamic in nature, especially for complex environments resulting from steady innovation and high competitive pressure. We addressed this issue from a complexity perspective, using an agent based simulation to visualize the key elements of efficient, information-based, collaborative decision making. Our findings suggested that information and communication technologies (ICT) may not be able to leverage corporate performance of the increasingly complex adaptive organizations. There seem to be elementary natural constraints on the cognitive capacities of people dealing with and managing information. Rather than a better technical approach, a more ecologic one is therefore advocated as the best way to improve decision making.

Mechanical stimulation to stimulate formation of a physiological collagen architecture in tissue-engineered cartilage: a numerical study

The load-bearing capacity of today's tissue-engineered (TE) cartilage is insufficient. The arcade-like collagen network in native cartilage plays an important role in its load-bearing properties. Inducing the formation of such collagen architecture in engineered cartilage can, therefore, enhance mechanical properties of TE cartilage. Considering the well-defined relationship between tensile strains and collagen alignment in the literature, we assume that cues for inducing this orientation should come from mechanical loading. In this study, strain fields prescribed by loading conditions of unconfined compression, sliding indentation and a novel loading regime of compression–sliding indentation are numerically evaluated to assess the probability that these would trigger a physiological collagen architecture. Results suggest that sliding indentation is likely to stimulate the formation of an appropriate superficial zone with parallel fibres. Adding lateral compression may stimulate the formation of a deep zone with perpendicularly aligned fibres. These insights may be used to improve loading conditions for cartilage tissue engineering.

Greek airport capacity utilisation: what about airfreight?

The paper examines capacity availability in 11 Greek airports in order to explore the possibilities of attracting airfreight traffic. Capacity is estimated based on the minimum value observed between apron and runway service ability. Secondary data are used for the estimation of capacity and traffic demand, based on the number of planes handled per hour. Utilisation levels are estimated on today's capacity and traffic figures. A projection based on different demand growth scenarios is also made for the year 2030. Results show that most Greek airports have significant capacity available, which stays idle for most of the 18-hour time frame used here. Runway appears to be the capacity factor that constrains airport operations more. Among the factors that decision-makers should consider in attracting new airfreight demand is the examination of the pricing policies followed, the competitiveness levels of airports and the necessary infrastructure required for the handling of this type of demand.

Matriz energética brasileira: uma prospectiva

O artigo apresenta uma prospectiva do setor energético brasileiro para o período 2005-30. As projeções apontam que o consumo de energia crescerá a taxas superiores às das últimas décadas e que a expansão da oferta energética poderá superar o dobro da atual capacidade instalada em todos os segmentos, especialmente os de petróleo, gás natural, etanol e eletricidade.

The Expansion of the U.S. Stock Market, 1885–1930: Historical Facts and Theoretical Fashions

Based on an analysis of the leading trading markets for stock in the United States, I document the dramatic expansion that took place in the scale and scope of the country's stock market from the mid-1880s to the early 1930s. My analysis suggests that a broadbased stock market was a long way from being established even by the early teens. It took the impetus provided by World War I, plus the enthusiasm of the 1920s, to bring such a market into existence. I consider the capacity of today's fashionable theories, which link the development of stock markets to improvements in minority shareholder protection, to explain the growth of the U.S. stock market, and find that they cannot account for the historical patterns that I identify. However, I suggest that there are other arguments that are worthy of further consideration. First, there were factors, besides minority shareholder rights, that led to changes in the demand for corporate stocks during this period, especially an increase in the demand for stocks by institutional investors, notably banks and insurance companies, as well as the emergence of a retail market for stocks after World War I. Second, there were also important developments in the supply of corporate stocks after the War, including the issuance of stock to fund the expansion of young firms, but especially to facilitate mergers and acquisitions by established firms, which seem to have played an important role in driving the expansion of the U.S. stock market.

The Expansion of the U.S. Stock Market, 1885–1930: Historical Facts and Theoretical Fashions

Based on an analysis of the leading trading markets for stock in the United States, I document the dramatic expansion that took place in the scale and scope of the country's stock market from the mid-1880s to the early 1930s. My analysis suggests that a broadbased stock market was a long way from being established even by the early teens. It took the impetus provided by World War I, plus the enthusiasm of the 1920s, to bring such a market into existence. I consider the capacity of today's fashionable theories, which link the development of stock markets to improvements in minority shareholder protection, to explain the growth of the U.S. stock market, and find that they cannot account for the historical patterns that I identify. However, I suggest that there are other arguments that are worthy of further consideration. First, there were factors, besides minority shareholder rights, that led to changes in the demand for corporate stocks during this period, especially an increase in the demand for stocks by institutional investors, notably banks and insurance companies, as well as the emergence of a retail market for stocks after World War I. Second, there were also important developments in the supply of corporate stocks after the War, including the issuance of stock to fund the expansion of young firms, but especially to facilitate mergers and acquisitions by established firms, which seem to have played an important role in driving the expansion of the U.S. stock market.

Effects of varying operating tension and speed on lateral tape motion in MP and AME tapes using magnetic signal and optical probe methods

The drive for increased storage capacity in today's magnetic tape cartridges has created a continuing need to improve the understanding of the tribological performance of magnetic tape. One important area of ongoing tribological research is lateral tape motion (LTM). The importance of studying LTM will only continue to grow, as the demands for more storage capacity move forward. One particular area of interest with regard to LTM is to determine the effects of the operating tension and speed on LTM generation. As such, this study focuses on LTM in six different tape samples when the operating tension and speed are varied. The tapes studied include metal particulate (MP), Thin MP, and four advanced metal evaporated (AME) tapes. A new technique based on the readback of a written magnetic signal was used in making LTM measurements. The results from the new method are compared to the results from the optical probe method used frequently in the past. Mechanisms responsible for the observed trends are discussed.

Application of hybrid metaheuristics in sensor management

The capacity of today's sensor systems has rapidly grown beyond the borders of human controllability. The real time (re)scheduling that is needed to manage them can only be done using state of the art planning and scheduling methods. This paper discusses one of the most recent and promising advances in operations research and artificial intelligence planning systems: hybrid metaheuristics. These robust heuristic search techniques efficiently use limited time and computing resources to produce good schedules within short term. Simulations show the use and performance of these techniques in multi-function radar systems.

Effects of Different Magnetic Tapes and Operating Parameters on Lateral Tape Motion in a Linear Tape Drive

The need for increased storage capacity in today's data storage technology has created a continuing need to study the tribological performance of magnetic tape. Lateral tape motion (LTM) is one important area of ongoing tribological research. The objective of the study presented in this article is to determine the effects different magnetic tapes and operating parameters have on LTM. Specifically, the research focuses on LTM in five different tape samples and the effects the varying operating parameters have on LTM. The tapes studied include metal particulate (MP), thin MP, and three advanced metal evaporated (AME) tapes, as well as MP tapes with different edge quality and tapes from staggered packs. The operating parameters studied include tension, speed, and head and bearing setup. Experimental methods used to collect and analyze the LTM data are discussed and the findings are presented.

Peer-to-Peer Based Multimedia Distribution Service

Recently, there are many research interests in providing efficient and scalable multimedia distribution service. However, stringent quality-of-service (QoS) requirements for media distribution, as well as dynamically changing and heterogeneous network capacity in today's best effort Internet, bring many challenges. In this paper, we introduce a novel framework for multimedia distribution service based on peer-to-peer (P2P) networks. A topology-aware overlay is proposed in which hosts self-organize into groups. End hosts within the same group have similar network conditions and can easily collaborate with each other to achieve QoS awareness. In order to improve media delivery quality and provide high service availability, we further propose two distributed heuristic replication strategies, intergroup replication and intragroup replication, based on this topology-aware overlay. Specifically, intergroup replication is aimed to improve the efficiency of media content delivery between the group where a request is issued and the group where the content is stored. Also, intragroup replication is targeted at improving the availability of the content. Extensive simulation results show that the latency in our proposed architecture is 20% less than that of the FreeNet and 50% less than that of the randomly replication system. Simulation results also show that the video quality in our system is much better than that in the other two systems. Our P2P-based approach is also distributed, scalable, cost effective, and aware of the performance.

All-optical address recognition for optically-asisisted routing in next-generation optical networks

Optical fiber communication technology enabled high-speed, long-distance capacity in today's networks. The packet switching functions such as address recognition and routing are performed in the electrical domain after optical-to-electrical conversion. As more real-time applications come online, demand for bandwidth increases, and electronic processing may potentially become a bottleneck at the intermediate nodes along the network. We introduce some optical address recognition schemes for optically-assisted routing that may decrease the processing delay at these nodes.

A RAM-economizing domain decomposition technique for regional high-resolution groundwater simulation

A major limitation of the use of high-resolution groundwater models on a regional scale for resource management by water companies is the excessive RAM requirements of such models which surpass the capacity of today's PCs. A strategy is presented to overcome this problem by using overlapping domain decomposition techniques. Furthermore, because very long computing time is the bottleneck for the practical use of this technique for large groundwater models, an analysis is also presented of a number of methods implemented to increase calculation performance. The approach presented here is characterized by a fairly simple structure that represents a generalized relaxation algorithm. It can be adapted for use with finite element as well as with finite difference methods.

Serving Tomorrow's Mega-Size Containerships: The Canadian Solution

Continued growth of global containerisation led to the deployment of larger cellular container vessels. Many industry forecasters suggest the next generation of mega-size container ships will be 12,000 to 16,000+ TEU. These massive ships (about twice the capacity of today's largest container ships) will serve only a limited number of deep water or off-shore transshipment hub ports. There are four Canadian deep-water ports that could be considered for on-shore hub port development: Vancouver and Prince Rupert on the west coast, and Halifax and Canso on the east coast. Developing these major hub ports to serve North America's primary container trade are projects of national and international scope. Achieving this vision requires dedicated national and regional task forces to ensure infrastructure is in place, funding available, and legislative constraints eliminated.

Pedagogical Benefits of the Computer in the Foreign Language Business Course

Critical commentary on the role of the computer in foreign language education has concerned itself too narrowly with drill materials. Pusack asserts, Since the computer itself has no capacity of understanding and no internal analogy for the relationships expressed in sentences, a CAI (computer assisted instruction) program must generate drill material as a series of tasks, usually questions and answers or cues and responses. Student-initiated questions and free form answers lie outside the capacity of today's machines and programs, except in highly restricted contexts. A very different kind of potential pedagogical benefit emerges when the computer is used as a much broader based element of foreign language instruction.

Future Air Force Tactical Communications

During the 1980's, many improvements will be made in the Air Force's ability to communicate in a battlefield environment. Programs like JTIDS, SEEK TALK, TRI-TAC, and the Ground Mobile Forces satellite communications terminals will improve the security, jam resistance, connectivity, and capacity of today's Air Force tactical communications. Even after these programs have been implemented, however, some important problem areas will remain, especially in our ability to resist a determined enemy's electronic warfare and physical attacks. This paper first describes today's Air Force tactical communications requirements and capabilities, and then summarizes the current problem areas. Currently planned programs to solve these problems are described for aircraft voice, aircraft data, ground-to-ground interconnections, and sensor/weapon data links. The problem areas that will remain after the implementation of these programs are then discussed. Some important technological opportunities are identified that hold promise for overcoming some of the projected problem areas in the 1990's. In addition, some system approaches are suggested for exploiting these technological opportunities, and for improving our use of older technologies. These system approaches emphasize reduced-information-rate operation, adaptive network techniques, network management/control, packet switching, and joint-Service, interoperable, common-user systems.