Femoral lengthening with a rail external fixator: tips and tricks

Lengthening the femur with an external fixator is commonly practised for a wide variety of pathologies. This technical report includes tips derived from observation and experience in a busy limb reconstruction unit. It focuses on the use of a rail fixator, although some of the descriptions are applicable to lengthening by circular fixators

Design Related Investigations for Media Access Control Protocol Service Schemes in Wavelength Division Multiplexed All Optical Networks

All-optical networks (AON) are emerging through the technological advancement of various optical components, and promise to provide almost unlimited bandwidth. To realise true network utilisation, software solutions are required. An active area of research is media access control (MAC) protocol. This protocol should address the multiple channels by wavelength division mutiplexing (WDM) and bandwidth management. Token-passing (TP) is one such protocol, and is adopted due to its simplicity and collisionless nature. Previously, this protocol has been analysed for a single traffic type. However, such a study may not substantiate the protocol's acceptance in the AON design. As multiple traffic types hog the network through the introduction multimedia services and Internet, the MAC protocol should support this traffic. Four different priority schemes are proposed for TP protocol extension, and classified as static and dynamic schemes. Priority assignments are a priori in static scheme, whereas in the other scheme, priority reassignments are carried out dynamically. Three different versions of dynamic schemes are proposed. The schemes are investigated for performance through analytical modelling and simulations. The semi-Markov process (SMP) modelling approach is extended for the analyses of these cases. In this technique, the behaviour of a typical access node needs to be considered. The analytical results are compared with the simulation results. The deviations of the results are within the acceptable limits, indicating the applicability ofthe model in all-optical environment. It is seen that the static scheme offers higher priority traffic better delay and packet loss performance. Thus, this scheme can be used beneficially in hard real-time systems, where knowledge of priority is a priori. The dynamic priority scheme-l is more suitable for the environments where the lower priority traffic is near real-time traffic and loss sensitive too. For such a scheme, a larger buffer with smaller threshold limits resulted in improved performance. The dynamic scheme-2 and 3 can be employed to offer equal treatment for the different traffic types, and more beneficial in future AONs. These schemes are also compared in their performance to offer constant QoS level. New parameters to facilitate the comparison are proposed. It is observed that the dynamic scheme-l outperforms the other schemes, and these QoS parameters can be used for such QoS analysis. It is concluded that the research can benefit the design of the protocol and its service schemes needed in AON system and its applications

The Proper Basis for Exercising Jurisdiction in Internet Disputes: Strengthening State Boundaries or Moving Towards Unification?

Private international law has developed on the premise of geographically discrete areas that could be effectively governed by nations with clear and delineated boundaries. The nature of internet communications however dissects and transcends national boundaries. In such a landscape of technological evolution, it is necessary to design new technologically-neutral principles for determining internet jurisdiction. While there is widespread agreement on the nature of the challenge posed by internet jurisdiction, there is significant divergence in the solutions proposed. The proposed solutions range from strengthening existing jurisdiction rules, to developing the present jurisdiction rules, to creating a new language of jurisdictional basis for the determination of internet disputes. After a consideration of the merits of the various veins of scholarship on this complex issue, it is recommended that the movement to unification through international convention provides the most effective solution to achieve consistency and certainty in the determination of jurisdiction in internet disputes

Mitigating the Legal Challenges Associated with Blockchain Smart Contracts: The Potential of Hybrid On-Chain/Off-Chain Contracts

Tantamount with the increasing application of blockchain technologies around the world, the use of blockchain-based smart contracts has rapidly risen. In a “smart contract,” computer protocols automatically facilitate, verify, and enforce arrangements made between parties on a blockchain. Such smart contracts offer a variety of commercial benefits, notably immutability and increased efficiency facilitated by removing the need for a trusted intermediary. However, as discussed in recent legal scholarship, it is difficult for smart contracts to uphold certain fundamental principles of contract law. Translating concepts of individual intention and responsibility into the decentralized space of blockchain is problematic. Aggregating such individual intention into the combined will and intention of the blockchain entity is at best challenging, and at worst unfeasible. Further, while traditional contracts accommodate change and allow for the amendment of terms in response to evolving circumstances, blockchain smart contracts do not. As the difficulties of blockchain smart contracts become apparent, attention is turning to hybrid smart contracts. “Hybrid” smart contracts are commonly described in legal discourse as arrangements that consist of both a traditional contract (natural language) and a blockchain-based smart contract (formal computer code) component. In comparison, computer science scholarship provides a more complex and nuanced articulation, framing hybrid smart contracts as arrangements that combine code running inside the blockchain (on-chain) with data and computations from outside the blockchain (off-chain). The link between these on-chain and off-chain operations is created through a decentralized oracle network. Such hybrid contracts maintain the immutability of blockchain, and the trustless contracting this facilitates, with the flexibility that comes from connecting to real-world, real-time data sources. In such a context, the objective of this Essay is to examine the nature and operation of hybrid smart contracts, integrating both legal and computer science discourse, and to critically analyze whether such arrangements have the potential to mitigate some of the legal challenges that have been identified with respect to fully on-chain smart contracts

RELIABILITY ASSESSMENT OF FREE SPANNING OFFSHORE PIPELINE

Pipeline from offshore petroleum fields must have frequently prone to many threats such as corrosion, free spanning, extreme weathers and etc. This study will be only concentrated on free spanning of offshore pipeline. The presence of free span along the length of pipeline may result in excessive displacement and bending or vibration of the pipeline section. The research will begin with data gathering of pipeline from Malaysian Water Operation. All data related to the pipelines are gathered. This study is divided into three major parts which are the study of the length of pipeline span, bending moment capacity of pipeline and also the stress analysis in the pipeline. These are the three elements which can cause failure to the pipelines. Thus, an assessment analysis of free spanning pipeline is crucial in order to ensure the reliability of these pipelines. All equations are developed by using the data obtained f. Then, Limit State Function is developed for this research. From the limit state function, probability of failure of pipelines according to each category can be obtained. Software’s were used to conduct the study. Software’s that were used are BestFit, to get the distribution of the data and VaP to get the probability of the pipeline to fail. At the end of the research, all three failure modes is compared to get the best reliable mode according to the probability of failure for each mode

The Influence of Viscoelastic Damping on the Dynamics — Behavior of an Embedded Foundation

The present paper examines the problem of the dynamic behavior of a rigid circular foundation deeply embedded in bonded contact with a viscoelastic soil mass of infinite extent. The viscous phenomena are accounted for by the introduction of a complex shear modulus. By employing a rigorous mathematical analysis of the problem an explicit results is derived for the dynamic axial compliance of the embedded foundation. The numerical results presented in the paper illustrate the manner in which viscous damping influences this compliance

The pelvic support osteotomy: indications and preoperative planning

The pelvic support osteotomy is a double level femoral osteotomy with the objective of eliminating a Trendelenburg and short limb gait in young patients with severe hip joint destruction as a consequence of neonatal septic arthritis. The osteotomy has seen several changes and a brief historical overview is provided to set the evolution of the modifications of the procedure in context. We present an analysis of the preoperative assessment that will assist the surgeon to plan out the procedure. Specifically, we set out to answer the following questions: (a) Where should the first osteotomy be performed and what is the magnitude of valgus and extension correction desired at this level? (b) Where should the second osteotomy be performed and what is the magnitude of varus and derotation desired at this level