An algorithm to median shortest path problem (MSPP) in the design of urban transportation networks

This paper proposes an efficient solution algorithm for realistic multi-objective median shortest path problems in the design of urban transportation networks. The proposed problem formulation and solution algorithm to median shortest path problem is based on three realistic objectives via route cost or investment cost, overall travel time of the entire network and total toll revenue. The proposed solution approach to the problem is based on the heuristic labeling and exhaustive search technique in criteria space and solution space of the algorithm respectively. The first labels each node in terms of route cost and deletes cyclic and infeasible paths in criteria space imposing cyclic break and route cost constraint respectively. The latter deletes dominated paths in terms of objectives vector in solution space in order to identify a set of Pareto optimal paths. The approach, thus, proposes a non-inferior solution set of Pareto optimal paths based on non-dominated objective vector and leaves the ultimate decision to decision-makers for purpose specific final decision during applications. A numerical experiment is conducted to test the proposed algorithm using artificial transportation network. Sensitivity analyses have shown that the proposed algorithm is advantageous and efficient over existing algorithms to find a set of Pareto optimal paths to median shortest paths problems.

Determinants of health-related quality of life in people with Parkinson’s disease: a path analysis

Purpose:
To identify the demographic factors, impairments and activity limitations that contribute to health-related quality of life (HRQOL) in people with idiopathic Parkinson’s disease (PD).

Method:
Two hundred and ten individuals with idiopathic PD who participated in the baseline assessment of a randomized clinical trial were included. The Parkinson’s Disease Questionnaire-39 summary index was used to quantify HRQOL. In order to provide greater clarity regarding the determinants of HRQOL, path analysis was used to explore the relationships between the various predictors in relation to the functioning and disability framework of the International Classification of Functioning model.

Results:
The two models of HRQOL that were examined in this study had a reasonable fit with the data. Activity limitations were found to be the strongest predictor of HRQOL. Limitations in performing self-care activities contributed the most to HRQOL in Model 1 (β = 0.38; p < 0.05), while limitations in functional mobility had the largest contribution in Model 2 (β = −0.31; p < 0.0005). Self-reported history of falls was also found to have a significant and direct relationship with HRQOL in both models (Model 1 β = −0.11; p < 0.05; Model 2 β = −0.21; p < 0.05).

Conclusions:
Health-related quality of life in PD is associated with self-care limitations, mobility limitations, self-reported history of falls and disease duration. Understanding how these factors are inter-related may assist clinicians focus their assessments and develop strategies that aim to minimize the negative functional and social sequelae of this debilitating disease.

The complete fool: Insights and trajectories from an ancient path

This study presents a novel and accompanying exegesis which explore the fool behind the Fool by stripping away his usual costume and arenas of power and folly to expose an essence – an impulse of potentiality – that helps explain the Fool’s perpetuity and argues his critical significance as a catalyst for creative thinking.

Path planning for CNC machines considering centripetal acceleration and jerk

In planning an s-curve speed profile for a computer numerical control (CNC) machine, centripetal acceleration and its derivative have to be considered. In a CNC machine, these quantities dictate how much voltage and current should be applied to servo motor windings. In this paper, the necessity of considering centripetal jerk in speed profile generation especially in the look-ahead mode is explained. It is demonstrated that the magnitude of centripetal jerk is proportional to the curvature derivative of the path known as "sharpness". It is also explained that a proper limited jerk motion is only possible when a G2-continuous machining path is planned. Then using a simplified mathematical representation of clothoids, a novel method for approximating a given path with a sequence of clothoid segments is proposed. Using this method, a semi-parallel G2-continuous path with adjustable deviation from the original shape for a sample machining contour is generated. Maximum permissible feed rate for the generated path is also calculated.

Dynamic path determination policy for distributed multimedia content adaptation

Multimedia content adaptation allows the ever increasing variety of handheld devices such as Smartphones to access distributed rich media resources available on the Internet today. Path planning and determination is a fundamental problem in enhancing performance of distributed multimedia content adaptation systems. Most of the existing path determination mechanisms use static path determination criteria based solely on associating a path with a single behavior aggregate score. However, some criteria such as availability are best represented using different functionality rather than being accumulated into the aggregate score. Moreover, since selection criteria have different behavior towards the score, this principle need to be considered. In this paper, we propose a dynamic multi-criteria path determination policy that selects an optimal path to the content adaptation services that best meet the user preferences and QoS requirements. The performance of the proposed approach is studied in terms of score’s fairness and reliability under different variations. The results indicate that the proposed policy performs substantially better than the baseline policy.

SMEs and the potential for a collaborative path to environmental responsibility

Globally, the potential for small and medium-sized enterprises (SMEs) to collectively impact negatively on the environment is great. Therefore, the adoption, and maintenance, of environmentally responsible practices by this group of firms is especially critical. Studies of environmental practices successfully implemented by small firms have revealed that relationships with other firms, or other organizations, can contribute to greater awareness of the benefits of such activities and, therefore, enhance the possibility of environmental engagement. Collaborative relationships may provide opportunities for SMEs to overcome some of the barriers to implementing environmental initiatives associated with their size, and/or associated characteristics. This paper focuses on attitudes of SME owner-managers to a variety of environmental issues (including regulation and voluntary standards), and to collaborating with other firms (in either a formal or informal sense). The data this paper draws upon are from two waves of an ongoing longitudinal survey of New Zealand SMEs.