6 research outputs found
Reducing risks in spare parts service contracts with a long downtime constraint
This article investigates spare parts service contracts for capital goods. We consider a single-item, single-location inventory system that serves one customer with multiple machines. During the contract execution phase, the true demand rate is observed. It can differ from the estimated demand rate because of two factors: increased demand variation in finite horizon settings and a shift in the mean utilization of the machines by the user during the contract. When the true demand rate is higher than the estimated demand rate, the Original Equipment Manufacturer (OEM) is faced with higher-than-expected costs for the execution of the contract, and the asset user is generally faced with a higher number of extreme long downtime events. Therefore, we introduce the flexible-time contract, which ends after a predetermined number of demands. Using a Markov decision process, we prove that a state-dependent base stock policy is optimal under a flexible-time contract. Using simulation, we compare the flexible-time contract with the standard fixed-time contract. Our results show that the flexible-time contract reduces the costs for the OEM by up to 35% and prevents not meeting the agreed-on service level. We obtain similar results in a multi-item setting
IndustReal Dataset of Egocentric Videos for Procedure Understanding
The multi-modal IndustReal dataset, accompanying our publication "IndustReal: A Dataset for Procedure Step Recognition Handling Execution Errors in Egocentric Videos in an Industrial-Like Setting". Check out our GitHub for additional details and read-me files. Unlike currently available datasets, IndustReal contains procedural errors (such as omissions) as well as execution errors. A significant part of these errors are exclusively present in the validation and test sets, making IndustReal suitable to evaluate robustness of algorithms to new, unseen mistakes. Additionally, to encourage reproducibility and allow for scalable approaches trained on synthetic data, the 3D models of all parts are publicly available
Extension to IndustReal Dataset: Assembly State Recognition with Error States
This dataset contains the assembly state images and annotations as an extension to the public IndustReal dataset. Whereas the original dataset only classifies assembly errors as "error class", we define fine-grained annotations and error type classifications for every assembly error in the dataset. These labels enable researchers to continue studying procedural and execution errors in assembly and maintenance tasks
LiMeS-lab: An integrated laboratory for the development of Liquid-Metal Shield technologies for fusion reactors
The liquid metal shield laboratory (LiMeS-Lab) will provide the infrastructure to develop, test, and compare liquid metal divertor designs for future fusion reactors. The main research topics of LiMeS-lab will be liquid metal interactions with the substrate material of the divertor, the continuous circulation and capillary refilling of the liquid metal during intense plasma heat loading and the retention of plasma particles in the liquid metal. To facilitate the research, four new devices are in development at the Dutch Institute for Fundamental Energy Research and the Eindhoven University of Technology: LiMeS-AM: a custom metal 3D printer based on powder bed fusion; LiMeS-Wetting, a plasma device to study the wetting of liquid metals on various substrates with different surface treatments; LiMeS-PSI, a linear plasma generator specifically adapted to operate continuous liquid metal loops. Special diagnostic protection will also be implemented to perform measurements in long duration shots without being affected by the liquid metal vapor; LiMeS-TDS, a thermal desorption spectroscopy system to characterize deuterium retention in a metal vapor environment. Each of these devices has specific challenges due to the presence and deposition of metal vapors that need to be addressed in order to function. In this paper, an overview of LiMeS-Lab will be given and the conceptual designs of the last three devices will be presented
Supplementary Material for: Inference-Based Cognitive Behavioral Therapy versus Cognitive Behavioral Therapy for Obsessive-Compulsive Disorder: A Multisite Randomized Controlled Non-Inferiority Trial
Introduction: Although cognitive behavioral therapy (CBT) effectively treats obsessive-compulsive disorder (OCD), many patients refuse CBT or drop out prematurely, partly because of anxiety regarding exposure and response prevention (ERP) exercises. Inference-based cognitive behavioral therapy (I-CBT) focuses on correcting distorted inferential thinking patterns, enhancing reality-based reasoning, and addressing obsessional doubt by targeting underlying dysfunctional reasoning, without incorporating an ERP component. We hypothesized that I-CBT would be non-inferior to CBT. Additionally, we hypothesized that I-CBT would be more tolerable than CBT. Methods: 197 participants were randomly assigned to 20 sessions CBT or I-CBT and assessed at baseline, post-treatment, and 6 and 12 months follow-up. The primary outcome was OCD symptom severity measured using the Yale-Brown Obsessive Compulsive Severity Scale (Y-BOCS; non-inferiority margin: 2 points). The secondary outcome, treatment tolerability, was assessed using the Treatment Acceptability/Adherence Scale (TAAS). A linear mixed-effects model was used to assess the non-inferiority of the primary outcome and superiority of secondary outcomes. Results: Statistically significant within-group improvements in the primary and secondary outcomes were observed in both treatments. No statistically significant between-group differences in Y-BOCS were found at any assessment point, but the confidence intervals exceeded the non-inferiority threshold, making the results inconclusive. The estimated mean post-treatment TAAS score was significantly higher in the I-CBT group than in the CBT group. Conclusion: While both CBT and I-CBT are effective for OCD, whether I-CBT is non-inferior to CBT in terms of OCD symptom severity remains inconclusive. Nevertheless, I-CBT offers better tolerability and warrants consideration as an alternative treatment for OCD
Supplementary Material for: Inference-Based Cognitive Behavioral Therapy versus Cognitive Behavioral Therapy for Obsessive-Compulsive Disorder: A Multisite Randomized Controlled Non-Inferiority Trial
Introduction: Although cognitive behavioral therapy (CBT) effectively treats obsessive-compulsive disorder (OCD), many patients refuse CBT or drop out prematurely, partly because of anxiety regarding exposure and response prevention (ERP) exercises. Inference-based cognitive behavioral therapy (I-CBT) focuses on correcting distorted inferential thinking patterns, enhancing reality-based reasoning, and addressing obsessional doubt by targeting underlying dysfunctional reasoning, without incorporating an ERP component. We hypothesized that I-CBT would be non-inferior to CBT. Additionally, we hypothesized that I-CBT would be more tolerable than CBT. Methods: 197 participants were randomly assigned to 20 sessions CBT or I-CBT and assessed at baseline, post-treatment, and 6 and 12 months follow-up. The primary outcome was OCD symptom severity measured using the Yale-Brown Obsessive Compulsive Severity Scale (Y-BOCS; non-inferiority margin: 2 points). The secondary outcome, treatment tolerability, was assessed using the Treatment Acceptability/Adherence Scale (TAAS). A linear mixed-effects model was used to assess the non-inferiority of the primary outcome and superiority of secondary outcomes. Results: Statistically significant within-group improvements in the primary and secondary outcomes were observed in both treatments. No statistically significant between-group differences in Y-BOCS were found at any assessment point, but the confidence intervals exceeded the non-inferiority threshold, making the results inconclusive. The estimated mean post-treatment TAAS score was significantly higher in the I-CBT group than in the CBT group. Conclusion: While both CBT and I-CBT are effective for OCD, whether I-CBT is non-inferior to CBT in terms of OCD symptom severity remains inconclusive. Nevertheless, I-CBT offers better tolerability and warrants consideration as an alternative treatment for OCD
