Fast Adaptive Temperature-Based Re-Optimization Strategies for On-Line Hot Spot Suppression during Locoregional Hyperthermia

Background: Experience-based adjustments in phase-amplitude settings are applied to suppress treatment limiting hot spots that occur during locoregional hyperthermia for pelvic tumors. Treatment planning could help to further optimize treatments. The aim of this research was to develop temperature-based re-optimization strategies and compare the predicted effectiveness with clinically applied protocol/experience-based steering. Methods: This study evaluated 22 hot spot suppressions in 16 cervical cancer patients (mean age 67 ± 13 year). As a first step, all potential hot spot locations were represented by a spherical region, with a user-specified diameter. For fast and robust calculations, the hot spot temperature was represented by a user-specified percentage of the voxels with the largest heating potential (HPP). Re-optimization maximized tumor T90, with constraints to suppress the hot spot and avoid any significant increase in other regions. Potential hot spot region diameter and HPP were varied and objective functions with and without penalty terms to prevent and minimize temperature increase at other potential hot spot locations were evaluated. Predicted effectiveness was compared with clinically applied steering results. Results: All strategies showed effective hot spot suppression, without affecting tumor temperatures, similar to clinical steering. To avoid the risk of inducing new hot spots, HPP should not exceed 10%. Adding a penalty term to the objective function to minimize the temperature increase at other potential hot spot locations was most effective. Re-optimization times were typically ~10 s. Conclusion: Fast on-line re-optimization to suppress treatment limiting hot spots seems feasible to match effectiveness of ~30 years clinical experience and will be further evaluated in a clinical setting.

A large-scale real-life crowd steering experiment via arrow-like stimuli

We introduce “Moving Light”: an unprecedented real-life crowd steering experiment that involved about 140.000 participants among the visitors of the Glow 2017 Light Festival (Eindhoven, NL). Moving Light targets one outstanding question of paramount societal and technological importance: “can we seamlessly and systematically influence routing decisions in pedestrian crowds?” Establishing effective crowd steering methods is extremely relevant in the context of crowd management, e.g. when it comes to keeping floor usage within safety limits (e.g. during public events with high attendance) or at designated comfort levels (e.g. in leisure areas). In the Moving Light setup, visitors walking in a corridor face a choice between two symmetric exits defined by a large central obstacle. Stimuli, such as arrows, alternate at random and perturb the symmetry of the environment to bias choices. While visitors move in the experiment, they are tracked with high space and time resolution, such that the efficiency of each stimulus at steering individual routing decisions can be accurately evaluated a posteriori. In this contribution, we first describe the measurement concept in the Moving Light experiment and then we investigate quantitatively the steering capability of arrow indications.

A novel assist-steering method with direct yaw moment for distributed-drive articulated heavy vehicle

This paper presents a novel assist-steering method for distributed-drive articulated heavy vehicles (DAHVs) to reduce its dependency on hydraulic steering method and improve the pressure characteristics of hydraulic struts. The objective is to realise the electrification of steering process for DAHVs, which is the basis of unmanned design with more stable control in the following studies. The theory and purpose of the proposed assist-steering method in this paper distinguishes it from the traditional direct yaw-moment control method or assist-steering methods in the previous studies, which easily produce interference with hydraulic steering method in DAHVs during steering process. In this paper, an accurate vehicle model is developed along with the field test for its satisfactory verification. Meanwhile, with the decoupling analyses of two different effects of steering methods on vehicle steering process, the assist-steering method is developed. In order to show the advantages brought on by this method, a case study is performed and analyzed. The results demonstrate that this proposed method can reduce the pressure of hydraulic steering system to about 41.2% without any changes of steering process, which is limited by the drive ability of wheel-side motor. Moreover, the pressure of inlet chamber in hydraulic struts is always reduced to about 40%–60% without any changes of the pressure in outlet chamber, which can improve the working performance of hydraulic steering system.

Valtionavustukset kulttuuripolitiikan ohjausvälineinä – huomioita opetus- ja kulttuuriministeriölle tehdystä pika-analyysistä

The text draws upon an assignment carried out by the Foundation for Cultural Policy Research (Cupore) for the Finnish Ministry of Education and Culture. The task was to map out the system of discretionary grants in cultural policy to point out weaknesses in strategic goal setting and attainment. The commission was motivated by the pressure to demonstrate effectiveness within the framework of the state management and steering system. The mapping was focused on grants that the Ministry allocates under the rubric ‘arts and culture’. This concerns some 50 different grant forms, amounting to EUR 55 million in 2013. The Cupore research team looked into details in the grant allocation practices, e.g., formulations of grant targets in the calls for application and wordings on the application forms. We also made an e-mail questionnaire on the presenting officers. It was concluded that discretionary grants in culture make up rather an incoherent and heterogeneous system. Some grant forms derive from the 19th century, prior to any cultural policy proper, while others are the product of recent targeted programmes. The strategy for cultural policy launched by the Ministry in 2009 was reflected only in places in the grant system. It was moreover noted that the goals of cultural policy were not entirely clear to provide basis for assessment of effectiveness. The policy sector emerged in many respects as a silo resisting alignment with renewed state management and steering methods. Several suggestions were made to the Ministry to control effectiveness, e.g., improved communication of grant policy goals, target guidance schemes with major grant recipients and co-ordination of grants as part of the cultural policy tools system.

Driftsformer og idrætsfaciliteter – hvordan åbnes den “sorte boks”?

Organizational behavioural patterns of Sport FacilitiesThis article develops hypotheses on how different steering methods influence patterns of action in Sport Facilities. It is firstly argued that the sport facility run by the City Council seen from a normative institutional perspective will focus on other user groups than those who use the facility today. This is due to an increased focus from the City Council on Sport for All. Secondly, from a rational institutional perspective, the sport facility run by the City Council will keep focus on existing users and public welfare institutions due the transaction costs of focusing on new users. Thirdly, private nonprofit sport facilities seen from a normative institutional approach might focus on existing users due to a ‘logic of appropriateness’ established between the users and the sport facility. Finally, seen from a rational institutional perspective on non-profit private sport facilities, the hypothesis is that they will have an increased focus on attracting more activity to the sport facility as they will benefit economically. Which of these hypotheses that is most valid is an empirical question that needs to be tested in additional studies.

Schematic Design and Research on Steering Mechanism of Drilling Robot

Through the research on drilling robot at home and abroad, this paper divides steering methods into two types: steering caused by radial motion of body parts; steering caused by deflection of the head. Based on this classification, several schematic designs of steering mechanism are proposed. Respectively, structural design and principle analysis of steering mechanisms are carried out. And steering mechanism 3 is chosen the best one through comparison from the following aspects: No. of motors in the steering mechanism, size, turning radius and control difficulty. In order to prove its feasibility theoretically, the detailed modeling and analysis are presented. The results of DOF (degree of freedom) calculation and kinematics simulation of the head point show that its motion is determined and no collision exists between the parts during the kinematical process. The relation among peak value of rollers’ trajectory H, distances from rollers to the rotation axis of the cylindrical cam r and maximum deflection angle θmax is analyzed by building the deflection model, which lays foundation for further optimization.