Interpreting risk allocation mechanism in public-private partnership projects : an empirical study in a transaction cost economics perspective

Risk allocation in public-private partnership (PPP) projects is currently claimed as capability driven. While lacking theoretical support, the claim is often 'violated' by current industrial practice. There is thus a need for formal mechanisms to interpret why a particular risk is retained by government in one project while transferred to private partners in another. From the viewpoint of transaction cost economics (TCE), integrated with the resource-based view (RBV) of organizational capabilities, this paper proposed a theoretical framework for understanding risk allocation practice in PPP projects. The theories underlying the major constructs and their links were articulated. Data gathered from an industry-wide survey were used to test the framework. The results of multiple linear regression (MLR) generally support the proposed framework. It has been found that partners' risk management routine, mechanism, commitment, cooperation history, and uncertainties associated with project risk management could serve to determine the risk allocation strategies adopted in a PPP project. This theoretical framework thus provides both government and private agencies with a logical and complete understanding of the process of selecting the allocation strategy for a particular risk in PPP projects. Moreover, it could be utilized to steer the risk allocation strategy by controlling certain critical determinants identified in the study. Study limitations and future research directions have also been set out.

Novel mechanism for evaluating feedback in the grid environment on resource allocation

The primary concern in proffering an infrastructure for general purpose computational grids formation is security. Grid implementations have been devised to deal with the security concerns. The chief factors that can be problematic in the secured selection of grid resources are the wide range of selection and the high degree of strangeness. Moreover, the lack of a higher degree of confidence relationship is likely to prevent efficient resource allocation and utilization. In this paper, we propose an efficient approach for the secured selection of grid resources, so as to achieve secure execution of the jobs. The presented approach utilizes trust and reputation for securely selecting the grid resources by also evaluation user’s feedback on the basis of the feedback already available about the entities. The proposed approach is scalable for an increased number of resources.

Multimedia content adaptation service discovery mechanism

Electronic information is becoming increasingly rich in content and varied in format and style while at the same time client devices are getting increasingly varied in their capabilities. This mismatch between rich contents and the end devices capability presents a challenge in providing seamless and ubiquitous access to electronic documents to interested users. Service-oriented content adaptation has emerged as a potential solution to the content-device mismatch problem. Since an adaptation task can potentially be performed by multiple content adaptation services (CAS), an approach for CAS discovery is a fundamental component of service-oriented content adaptation environment. In this paper, we propose a service discovery approach that considers the client device capability and the service’s attributes to discover appropriate CAS while optimizing performance and functionality. The efficiency of the proposed CAS discovery protocol is studied experimentally. The results show that the proposed discovery approach is effective in terms of discovering appropriate content adaptation services.

Force measurement capability for robotic assisted minimally invasive surgery systems

An automated laparoscopic instrument capable of non-invasive measurement of tip/tissue interaction forces for direct application in robotic assisted minimally invasive surgery systems_ is introduced in this paper. It has the capability to measure normal grasping forces as well as lateral interaction forces without any sensor mounted on the tip jaws. Further to non-invasive actuation of the tip, the proposed instrument is also able to change the grasping direction during surgical operation. Modular design of the instrument allows conversion between surgical modalities (e.g., grasping, cutting, and dissecting). The main focus of this paper is on evaluation of the grasping force capability of the proposed instrument. The mathematical formulation of fenestrated insert is presented and its non-linear behaviour is studied. In order to measure the stiffness of soft tissues, a device was developed that is also described in this paper. Tissue characterisation experiments were conducted and results are presented and analysed here. The experimental results verify the capability of the proposed instrument in accurately measuring grasping forces and in characterising artificial tissue samples of varying stiffness.

An investigation of effects of modification processes on physical properties and mechanism of drug release for sustaining drug release from modified rice

The aim of this study was to investigate the effect of modification processes on physical properties and explain the mechanism of sustained drug release from modified rice (MR). Various types of Vietnamese rice were introduced in the study as the matrices of sustained release dosage form. Rice was thermally modified in water for a determined temperature at different times with a simple process. Then tablets containing MR and isradipine, the model drug, were prepared to investigate the capability of sustained drug release. Scanning electron microscopy (SEM) was used to determine different morphologies between MR formulations. Flow property of MR was analyzed by Hausner ratio and Carr's indices. The dissolution rate and swelling/erosion behaviors of tablets were evaluated at pH 1.2 and pH6.8 at 37±0.5°C. The matrix tablet containing MR showed a sustained release as compared to the control. The SEM analyses and swelling/erosion studies indicated that the morphology as well as swelling/erosion rate of MR were modulated by modification time, drying method and incubation. It was found that the modification process was crucial because it could highly affect the granule morphologies and hence, leading to the change of flowability and swelling/erosion capacity for sustained release of drug.

Elucidation of transport mechanism and enhanced alkali ion transference numbers in mixed alkali metal-organic ionic molten salts

Mixed salts of Ionic Liquids (ILs) and alkali metal salts, developed as electrolytes for lithium and sodium batteries, have shown a remarkable ability to facilitate high rate capability for lithium and sodium electrochemical cycling. It has been suggested that this may be due to a high alkali metal ion transference number at concentrations approaching 50 mol% Li(+) or Na(+), relative to lower concentrations. Computational investigations for two IL systems illustrate the formation of extended alkali-anion aggregates as the alkali metal ion concentration increases. This tends to favor the diffusion of alkali metal ions compared with other ionic species in electrolyte solutions; behavior that has recently been reported for Li(+) in a phosphonium ionic liquid, thus an increasing alkali transference number. The mechanism of alkali metal ion diffusion via this extended coordination environment present at high concentrations is explained and compared to the dynamics at lower concentrations. Heterogeneous alkali metal ion dynamics are also evident and, somewhat counter-intuitively, it appears that the faster ions are those that are generally found clustered with the anions. Furthermore these fast alkali metal ions appear to correlate with fastest ionic liquid solvent ions.

A study on truss bolt mechanism in controlling stability of underground excavation and cutter roof failure

The truss bolt reinforcement system has been used in controlling the stability of underground excavations in severe ground conditions and cutter roof failure in layered rocks especially in coal mines. In spite of good application reports, working mechanism of this system is largely unknown and truss bolts are predominantly designed based on past experience and engineering judgement. In this study, the reinforcing effect of the truss bolt system on an underground excavation in layered rock is studied using non-linear finite element analysis. Different indicators are defined to evaluate the reinforcing effects of the truss bolt system. Using these indicators one can evaluate the effects of a reinforcing system on the deformation, loosened area, failure prevention, horizontal movement of the immediate layer, shear crack propagation and cutter roof failure of underground excavations. Effects of truss bolt on these indicators reveal the working mechanism of the truss bolt system. To illustrate the application of these indicators, a comparative study is conducted between three different truss bolt designs. It is shown that the design parameters of truss bolt systems, including tie-rod span, length, and angle of the bolts can have significant effects on the reinforcing capability of the system.