Pathological gait clustering in post-stroke patients using motion capture data.

BACKGROUND: Analyzing the complex gait patterns of post-stroke patients with lower limb paralysis is essential for rehabilitation. RESEARCH QUESTION: Is it feasible to use the full joint-level kinematic features extracted from the motion capture data of patients directly to identify the optimal gait types that ensure high classification performance? METHODS: In this study, kinematic features were extracted from 111 gait cycle data on joint angles, and angular velocities of 36 post-stroke patients were collected eight times over six months using a motion capture system. Simultaneous clustering and classification were applied to determine the optimal gait types for reliable classification performance. RESULTS: In the given dataset, six optimal gait groups were identified, and the clustering and classification performances were denoted by a silhouette coefficient of 0.1447 and F1 score of 1.0000, respectively. SIGNIFICANCE: There is no distinct clinical classification of post-stroke hemiplegic gaits. However, in contrast to previous studies, more optimal gait types with a high classification performance fully utilizing the kinematic features were identified in this study.

Demand risk transfer and government's cost efficiency: Focusing on Korean waste treatment PPP cases.

This study aimed to examine the government's cost efficiency considering the high-risk/high-return mechanism of PPP. Faced with increasing demand but with limited budget, the Korean government has relied on the Public-Private Partnership (PPP) to provide waste treatment services for the last couple of decades to expand fiscal space. However, most of waste treatment facilities projects have been promoted using the BTO (Build-Transfer-Operate) method with high rate of return due to the demand risk that is transferred to the private. We performed a conversion analysis of a BTO to a BTL (Build-Transfer-Lease) method, in which demand risk is borne by the government, for 18 PPP waste treatment cases with actual operation records. The result of comparing the life-cycle costs of government in employing each project method shows that the BTL can provide 5.26% of Value for Money (VfM) compared to the BTO as the government takes the demand risk and lowers the required rate of return of the private. This implies that transferring the demand risk to the private sector may not always be the best option for the government. From the government's perspective, instead of transferring the demand risk to the private and providing a high rate of return, the government can retain the demand risk and reduce the rate of return, and it can be fiscally more advantageous considering the cost structure of each PPP method. Through Korean PPP waste treatment cases, this study suggests that policy makers who implement PPP should consider the government's strategic risk sharing by understanding the predictability of demand and the nature of cost structure of each PPP method.