Multilevel Test Research Articles

Abrasive Wear Characteristics of 30MnB5 Steel for High-Speed Plough Tip of Agricultural Machinery in Southern Xinjiang Region

The high-speed plough tip is the core soil-touching component in southern Xinjiang field cultivation, but the interaction of the plough tip with the soil results in severe wear of the tip. The friction behaviour of sand and soil on plough tips was investigated with a homemade rotary abrasive wear tester in a one-factor multilevel test with three parameters: moisture content, velocity/rotational speed and friction distance. The objective was to study the friction behaviour of the sand soil and plough tip and analyse and characterise the wear amount, wear thickness and compressive stress distribution, three-dimensional wear morphology and microscopic wear morphology of the plough tips. The results show that with increasing speed, the wear amount changes more gently; with increasing soil water content, the soil adhesion force and lubricating water film increase so that the wear amount follows a second-order parabolic law; and with increasing friction distance, the wear amount gradually increases, and the wear rate also shows an upward trend when the plough tip is in the abrasive wear stage. The tip makes contact with the firmer soil with higher surface compressive stresses, causing the most wear. As the friction distance increases, sand particles become embedded in the contact surfaces, creating a groove effect along with spalling pits caused by fatigue wear. During the whole wear period, the groove effect is always accompanied by spalling pits appearing repeatedly. The analysis of the wear micromorphology of the plough tip shows that the number of flaking pits gradually decreases in the direction of soil movement, and the form of damage changes from impact wear to plough groove scratches. Abrasive wear interacts with corrosive wear to exacerbate plough tip wear.

Electrifying thermal loads vs. installing batteries: A case study on fast frequency resource potentials of the Victorian power system

Literature suggests different technologies and control algorithms to counteract the decrease in system damping and inertia caused by the increasing penetration of inverter-interfaced resources in renewable power systems. Published studies generally focus on comparing different control mechanisms for a single technology and examine a limited number of operating conditions. Technology comparisons are typically limited to small test cases, base on assumptions that no longer hold in renewable-rich systems or are solely based on literature reviews. This work thoroughly compares fast-frequency reserve provision from inverter-based active thermal loads (ATLs) against battery storage. As such, we employ a large-scale multi-level test case representing the future Victorian power system and link steady-state and dynamic analysis. We examine the frequency and voltage performance following distinct disturbances for five days with hourly resolutions. The results suggest that the potential for electrifying residential heating demand in Victoria is enormous and can significantly enhance frequency metrics. Generally, the improvements achieved with the aggregation of ATLs are similar or even higher than employing a large battery.

Immigrant Culture and Neighborhood Perceived Violent Crime and Violent Victimization: A Multi-Level Test of Enculturation to México, Acculturation to the US, and Support for the Code of the Street

Research on neighborhood immigration and crime rarely tests cultural explanations for the null or inverse associations typically found. We examine if support for the code of the street and measures of immigrant culture (acculturation and enculturation) mediate this relationship. We employ multilevel path modeling and survey data from neighborhoods in El Paso County, Texas, merged with census data. Supporting predictions, enculturation is inversely associated with support for the code of the street and enculturation mediates an indirect relationship between neighborhood immigration and neighborhood violent victimization. However, this relationship does not appear when perceived neighborhood violent crime is used as the dependent variable or the acculturation measure. While the code of the street is positively associated with both perceived neighborhood violent crime and violent victimization, it is not associated with neighborhood immigration and does not serve as a mediator. Implications for cultural explanations of the neighborhood immigration-crime association are discussed.

Enhancing the physical properties of cemented ultrafine tailings backfill (CUTB) with fiber and rice husk ash: Performance, mechanisms, and optimization

A series of experiments was conducted to study the performance and mechanisms of Cemented Ultrafine Tailings Backfill (CUTB). Firstly, the optimum fiber type was selected by single factor multilevel test. Secondly, the effects of cement content, rice husk ash content, fiber content and fiber length on backfill properties were analyzed by orthogonal test and microstructure test, and the influence mechanism of fiber and rice husk ash content was revealed. Finally, fuzzy mathematics theory is used to optimize the ratio parameters. The results show, compared to glass and basalt fiber, polypropylene fiber yields the most substantial enhancement in backfill strength. The increase of cement content, polypropylene fiber content and length can reduce slump, but the change of rice husk ash content has no obvious effect. Increased cement or fiber content effectively restrained the formation of primary fractures in CUTB, thus enhancing its integrity. Adding an optimal dosage range of 0–4 % of rice husk ash boosted the early compressive strength, albeiting at the expense of later compressive strength. Fiber addition with the optimum content range between 0.1 and 0.4 % enhanced the strengthening effect of cement content on compressive strength. Fiber primarily enhances the macroscopic strength of backfill through the dispersion and co-loading of forces, whereas rice husk ash enhances strength by optimizing void structure distribution. The optimal ratio parameters of a cement content of 310 kg/m³, rice husk ash content of 8.0 %, fiber content of 0.4 %, and fiber length of 9 mm were proposed finally.

Multilevel testing of constraints induced by structural equation modeling in fMRI effective connectivity analysis: A proof of concept

In functional MRI (fMRI), effective connectivity analysis aims at inferring the causal influences that brain regions exert on one another. A common method for this type of analysis is structural equation modeling (SEM). We here propose a novel method to test the validity of a given model of structural equation. Given a structural model in the form of a directed graph, the method extracts the set of all constraints of conditional independence induced by the absence of links between pairs of regions in the model and tests for their validity in a Bayesian framework, either individually (constraint by constraint), jointly (e.g., by gathering all constraints associated with a given missing link), or globally (i.e., all constraints associated with the structural model). This approach has two main advantages. First, it only tests what is testable from observational data and does allow for false causal interpretation. Second, it makes it possible to test each constraint (or group of constraints) separately and, therefore, quantify in what measure each constraint (or, e..g., missing link) is respected in the data. We validate our approach using a simulation study and illustrate its potential benefits through the reanalysis of published data.

Flexible and rigorous numerical modelling of multiphysics processes in fractured porous media using PorePy

Multiphysics processes in fractured porous media is a research field of importance for several subsurface applications and has received considerable attention over the last decade. The dynamics are characterized by strong couplings between processes as well as interaction between the processes and the structure of the fractured medium itself. The rich range of behaviour calls for explorative mathematical modelling, such as experimentation with constitutive laws and novel coupling concepts between physical processes. Moreover, efficient simulations of the strong couplings between multiphysics processes and geological structures require the development of tailored numerical methods.We present a modelling framework and its implementation in the open-source simulation toolbox PorePy, which is designed for rapid prototyping of multiphysics processes in fractured porous media. PorePy uses a mixed-dimensional representation of the fracture geometry and generally applies fully implicit couplings between processes. The code design follows the paradigms of modularity and differentiable programming, which together allow for extreme flexibility in experimentation with governing equations with minimal changes to the code base. The code integrity is supported by a multilevel testing framework ensuring the reliability of the code.We present our modelling framework within a context of thermo-poroelasticity in deformable fractured porous media, illustrating the close relation between the governing equations and the source code. We furthermore discuss the design of the testing framework and present simulations showcasing the extendibility of PorePy, as well as the type of results that can be produced by mixed-dimensional simulation tools.

Haemoglobinopathies: A Review on Statistical Modelling Perspective (Haemoglobinopathies: Statistical Modelling Techniques)

Haemoglobinopathies indicate a group of monogenic disorders. The prevalence of Haemoglobinopathies differs based on geographical regions and is higher in tropical countries. Literature has identified that Haemoglobinopathies are higher in tribal and ethnic groups compared to the general population in India. This narrative review explores the methods to analyse data related to Haemoglobinopathies, identifies the research gaps and gains insights on model building and prediction of Haemoglobinopathies. This narrative review includes articles focusing on Haemoglobinopathies, Anaemia and other related disorders, published from 2008 onwards. Full-text and accessible articles found in relevant databases were included. Statistical and a few other techniques like Logistic Regression, Bayesian Modelling, Genetic Risk Scoring, Structural Equation Modelling, Multilevel Tests, Longitudinal Models, Machine Learning Algorithms and Genotyping methods were used to know the risk of acquiring Haemoglobinopathies and to identify important genetic variants. From the findings, it was observed that many studies were conducted to identify the prevalence of Haemoglobinopathies among the general population, but only few in the tribal population. Models based on machine learning algorithms were used for prediction involving haematological parameters and genetic variants, whereas the statistical techniques for prediction include demographic, nutritional, economic, cultural and social indicators.

Особливості хімічного експерименту в умовах вимушеного дистанційного навчання

The article focuses on the study of online learning at school, the problems that arose during the school experiment and its impact on the quality of the acquired knowledge. The issue of the quality of knowledge obtained by means of distance learning, the organization of online practical and laboratory work, and the search for methods of diagnosing the quality of knowledge are quite relevant and in demand. The purpose of the study was to establish the level of quality of studying chemistry in the conditions of distance learning and to determine the factors affecting the success of students. The main tasks: to conduct a qualitative observation of the methods of conducting laboratory and practical work (experiments) during online classes and the attitude of students to distance learning and to study the influence of practical and laboratory work (experiments) in chemistry on the quality of knowledge and the identification of students' misconceptions in chemistry that arose during distance learning. It was established that the main common problems for chemistry teachers were finding ways to conduct laboratory and practical work, identifying false (false) ideas and diagnostic tools. According to the results of the student survey, the main disadvantages of distance learning in general and conducting laboratory-practical classes in particular were determined: loss of direct contact, problems with the Internet, lack of light, understanding of the material, lack of skills in working with laboratory equipment, inability to manage time, unfair assessment, as well as the fact that that teachers conduct classes too quickly, leaving no time for questions and discussion. This, obviously, reduces interest in disciplines, understanding of certain concepts and quality of knowledge and level of success. Increasing the share of school and home experiments in chemistry contributed to interest in the subject, understanding of the topic and had a positive effect on the quality of knowledge. According to the results of four knowledge controls, positive dynamics were observed: the average increase was 0.66 points: from 0.2 (for 7th grade students) to 1.1 points (for 11th grade students). The use of conversations and various multi-level tests allows not only to discover which ideas and knowledge students have, but also to understand what actions need to be taken to eliminate them.

Datasets of Simulated Exhaled Aerosol Images from Normal and Diseased Lungs with Multi-Level Similarities for Neural Network Training/Testing and Continuous Learning

Although exhaled aerosols and their patterns may seem chaotic in appearance, they inherently contain information related to the underlying respiratory physiology and anatomy. This study presented a multi-level database of simulated exhaled aerosol images from both normal and diseased lungs. An anatomically accurate mouth-lung geometry extending to G9 was modified to model two stages of obstructions in small airways and physiology-based simulations were utilized to capture the fluid-particle dynamics and exhaled aerosol images from varying breath tests. The dataset was designed to test two performance metrics of convolutional neural network (CNN) models when used for transfer learning: interpolation and extrapolation. To this aim, three testing datasets with decreasing image similarities were developed (i.e., level 1, inbox, and outbox). Four network models (AlexNet, ResNet-50, MobileNet, and EfficientNet) were tested and the performances of all models decreased for the outbox test images, which were outside the design space. The effect of continuous learning was also assessed for each model by adding new images into the training dataset and the newly trained network was tested at multiple levels. Among the four network models, ResNet-50 excelled in performance in both multi-level testing and continuous learning, the latter of which enhanced the accuracy of the most challenging classification task (i.e., 3-class with outbox test images) from 60.65% to 98.92%. The datasets can serve as a benchmark training/testing database for validating existent CNN models or quantifying the performance metrics of new CNN models.

ANALYSIS OF HIV AND SYPHILIS TRANSMISSION PREVENTION PROGRAMS FOR ADOLESCENTS

Background: Adolescents tend to want to try things they have never experienced, and the main contributing factor is curiosity and imitating what adults do, including sexuality. Aims: This study aimed to analyze the transmission prevention program of HIV and Syphilis for adolescents in North Sumatra. Methods: This study used an analytic survey approach with a cross-sectional design by taking 729 people as a sample, selected using quota sampling, from the total adolescent population (19.4% of the population of North Sumatra). Questionnaires produced using an online platform and adapted from The Prospero Network. The results were then transferred into a statistics-based application for descriptive data analysis, bivariate, and multi-level tests. Results: The study showed that >50% of the respondents took a quick, free laboratory test for HIV and syphilis and a reactive confirmation test through a health facility in both cases. Moreover, the results of multi-level statistical tests show models 1 and 2, namely the availability of syphilis screening referrals, have a 1-17 times higher risk of implementing HIV and syphilis programs in adolescents. Conclusion: Everything is interrelated with the implementation of HIV and Syphilis transmission prevention programs in adolescents. However, there is still a significant chance that it will not work. Therefore, the government and the community must work together to implement this program properly and consistently. Keywords: Adolescents, Health Program, HIV, Syphilis

ANALYSIS OF HIV AND SYPHILIS TRANSMISSION PREVENTION PROGRAMS FOR ADOLESCENTS

Background: Adolescents tend to want to try things they have never experienced, and the main contributing factor is curiosity and doing what adults, do including sexuality. Aims: The aim of this study was to analyze the transmission prevention program of HIV and Syphilis for adolescents in North Sumatra. Methods: Using an analytical survey approach with a cross-sectional design by taking 729 people as a sample from the total adolescent population of around 19.4% quota sampling, research instrument using questionnaires adopted from The Prospero Network and made through an online platform, then the results were transferred into a statistics-based application for descriptive data analysis, bivariate and multilevel test. Results: Showing >50% of respondents conducted HIV and Syphilis testing through the laboratory quickly and free of charge and reactive confirmatory tests on both cases through health facilities, multilevel statistical tests result known to models 1 and 2, namely, the availability of syphilis screening referrals have a risk of 1-17 times higher the implementation of HIV and Syphilis programs for adolescents. Conclusion: Everything is interrelated with the implementation of HIV and Syphilis transmission prevention programs in adolescents. However, the government and community must work together to consistently implement this program properly. Keywords: Adolescents, Health Program, HIV, Syphilis

Convolutional Neural Network Classification of Exhaled Aerosol Images for Diagnosis of Obstructive Respiratory Diseases

Aerosols exhaled from the lungs have distinctive patterns that can be linked to the abnormalities of the lungs. Yet, due to their intricate nature, it is highly challenging to analyze and distinguish these aerosol patterns. Small airway diseases pose an even greater challenge, as the disturbance signals tend to be weak. The objective of this study was to evaluate the performance of four convolutional neural network (CNN) models (AlexNet, ResNet-50, MobileNet, and EfficientNet) in detecting and staging airway abnormalities in small airways using exhaled aerosol images. Specifically, the model’s capacity to classify images inside and outside the original design space was assessed. In doing so, multi-level testing on images with decreasing similarities was conducted for each model. A total of 2745 images were generated using physiology-based simulations from normal and obstructed lungs of varying stages. Multiple-round training on datasets with increasing images (and new features) was also conducted to evaluate the benefits of continuous learning. Results show reasonably high classification accuracy on inbox images for models but significantly lower accuracy on outbox images (i.e., outside design space). ResNet-50 was the most robust among the four models for both diagnostic (2-class: normal vs. disease) and staging (3-class) purposes, as well as on both inbox and outbox test datasets. Variation in flow rate was observed to play a more important role in classification decisions than particle size and throat variation. Continuous learning/training with appropriate images could substantially enhance classification accuracy, even with a small number (~100) of new images. This study shows that CNN transfer-learning models could detect small airway remodeling (<1 mm) amidst a variety of variants and that ResNet-50 can be a promising model for the future development of obstructive lung diagnostic systems.

INFORMATION TECHNOLOGIES AT THE CLASSES OF UKRAINIAN AS A FOREIGN LANGUAGE IN THE CONDITIONS OF DISTANCE EDUCATION

Тhe role of the information technologies in the conditions of distance learning at the classes of the Ukrainian as a foreign language is analyzed in the article. The advantages of using of the innovative technologies in the modern educational process, in particular, during the study of the Ukrainian language as a foreign language, have been determined. Ways to overcome the communication barriers in the process of distance learning are identified, one of which is seemed to be in mastering of the information technologies. The important online tools for organizing a high-quality and interesting educational process are characterized. Available information means (interactive whiteboards, platforms, and other online resources) are described. For example, such information tools that contribute to the activation of students, diversify the means of communication between students and teachers, and allow creating a database of educational materials that is accessible and convenient for viewing at any time. Emphasis is placed on the problem of adaptation of foreign students in the conditions of distance learning. It could be noted that such adaptation is primarily facilitated by the selection of information resources for the organization of a high-quality educational process with the provision of feedback. Based on this criterion, a classification of online education tools at the classes of the Ukrainian as the foreign language is proposed. Therefore, information technologies are divided into several categories (which contribute to the activation of students at practical classes; which diversify the means of communication between students and teachers; which contribute to the qualitative assessment of students’ knowledge (multilevel testing system); which provide feedback; which allow creating a base of educational materials, accessible and convenient for viewing at any time. The advantages of working with a cloud environment for saving and reproducing educational materials are defined. For example, creating cases, sites, online textbooks with Book Creator. Ways to improve the informational competences of teachers of the Ukrainian as a foreign language are analyzed. Key words: information technologies, Ukrainian language as a foreign language, didactic process, distance learning, educational platforms.

A microservice-based framework for multi-level testing of cyber-physical systems

In the last years, the use of microservice architectures is spreading in Cyber-Physical Systems (CPSs) and Internet of Things (IoT) domains. CPSs are systems that integrate digital cyber computations with physical processes. The development of software for CPSs demands a constant maintenance to support new requirements, bug fixes, and deal with hardware obsolescence. The key in this process is code testing and more if the code is fragmented during the development of CPSs. It is important to remark that this process is challenging and time-consuming. In this paper, we report on the experience of instantiating of the microservice-based architecture for DevOps of CPSs to test elevator dispatching algorithms across different test levels (i.e., SiL, HiL and Operation). Such an architecture allows for a continuous deployment, monitoring and validation of CPSs. By integrating the approach with a real industrial case study, we demonstrate that our approach reduces significantly the time needed in the testing process and consequently, reduces the economic cost of the entire process.

Radiotherapy for Ledderhose disease: Results of the LedRad-study, a prospective multicentre randomised double-blind phase 3 trial

Background and purposeRadiotherapy is considered a treatment option for Ledderhose disease. However, its benefits have never been confirmed in a randomised controlled trial. Therefore, the LedRad-study was conducted. Materials and methodsThe LedRad-study is a prospective multicentre randomised double-blind phase three trial. Patients were randomised to sham-radiotherapy (placebo) or radiotherapy. The primary endpoint was pain reduction at 12 months after treatment, measured with the Numeric Rating Scale (NRS). Secondary endpoints were pain reduction at 6 and 18 months after treatment, quality of life (QoL), walking abilities and toxicity. ResultsA total of 84 patients were enrolled. At 12 and 18 months, patients in the radiotherapy group had a lower mean pain score compared to patients in the sham-radiotherapy group (2.5 versus 3.6 (p = 0.03) and 2.1 versus 3.4 (p = 0.008), respectively). Pain relief at 12 months was 74% in the radiotherapy group and 56% in the sham-radiotherapy group (p = 0.002). Multilevel testing for QoL scores showed higher QoL scores in the radiotherapy group compared to the sham-radiotherapy group (p < 0.001). Moreover, patients in the radiotherapy group had a higher mean walking speed and step rate with barefoot speed walking (p = 0.02). Erythema, skin dryness, burning sensations and increased pain were the most frequently reported side effects. These side effects were generally graded as mild (95%) and the majority (87%) were resolved at 18 months follow-up. ConclusionRadiotherapy for symptomatic Ledderhose disease is an effective treatment resulting in a significant pain reduction, improvement of QoL scores and bare feet walking abilities, in comparison to sham-radiotherapy.

Ethical leadership communications scale: Development and validation of a measure and multi-level test

Ethical leadership emphasizes the promotion of ethical behavior through two-way communication with followers. This article introduces the development of an ethical leadership communication scale that was created based on three categories of an ethical leadership conceptual framework, namely, the leader being an example of ethics in action, the leader treating his/her followers fairly, the leader actively managing morality. Relevant items were developed and subjected to factor analysis with a sample of 175 respondents from organization A, resulting in a 1-factor solution with 15 items. Using a 522-person sample from organizations B and C, we verified the 1-factor solution with 15-item with confirmatory factor analysis. We further validated the 15-item ethical leadership communication scale by regressing outcomes with structural equation modeling (SEM) from Organization D. We then tested the ethical leadership communication scale with the ethical leadership questionnaire and ethical leadership survey (ELS), and analyzed the data using multi-level hierarchical regression. Results suggest that the ethical leadership communication scale as a construct is a unique contribution beyond the ethical leadership constructs in explaining organizational citizenship behaviors. The new ethical leadership communication scale (the Ethical Leadership Communication Scale-15) demonstrates adequate reliability, validity, and across organization generalizability. Findings of this study further the model of ethical leadership and communication behavior and help to re-conceptualize the role of dyadic communication in ethical leadership. This study paves the way for finer-grained theorizing and analysis of ethical leadership and communication dynamics in the workplace.

The use of cardiometric and electrodermal activity indicators for the attestation of visual online content

The article presents some results of an interdisciplinary study aimed at clarifying the conditions for the use of cardiometric and electrodermal indicators of human activity as a means of attesting to visual online content. To record personal reactions to selected visual objects, the authors use a range of tools, including computer cardiometers, portable eye trackers and polygraphs of various modifications. To achieve this goal, the authors conducted a multi-level test of Russian youth using current political symbols and images from online communities and other social media platforms. The results of the study prove the high efficiency of using cardio-oculometric detection combined with automatic recording of electrodermal activity to obtain reliable information about affective and rational-logical features of perception of visual online content. The study also extends the research understanding of the specifics of using this combination of diagnostic tools in different conditions.

Radiotherapy for Ledderhose Disease: A Prospective, Multicenter, Randomized, Double-Blind, Phase III Trial (NCT03507010)

<h3>Purpose/Objective(s)</h3> Radiotherapy is considered a treatment option for Ledderhose disease. However, the added value of radiation has never been confirmed in a randomized controlled trial (RCT). The objective of this study was to test the hypothesis that radiotherapy significantly improves outcome in terms of symptom relief and quality of life in patients with Ledderhose disease as compared to sham-radiotherapy. <h3>Materials/Methods</h3> The LedRad-study is a prospective, multicenter, randomized, double-blind, phase III trial comparing radiotherapy to sham-radiotherapy (placebo), as treatment for patients with symptomatic Ledderhose disease. The main inclusion criteria were pain from Ledderhose disease (≥ 2 on the numeric rating scale (NRS)), no previous surgery and/or radiotherapy to the affected foot, and age ≥ 18 years. Stratification factors were age and gender. Radiotherapy consisted of 10 fractions of 3 Gy administered in two separate courses of five daily fractions, with an interval of 10 weeks. Procedures in both groups were identical, except that treatment delivery was simulated for the patients in the sham-radiotherapy arm. Unblinding of the treatment was performed 18 months after the end of (sham-)radiotherapy. The primary endpoint was pain reduction at 12 months after treatment, measured with the NRS. Secondary endpoints were pain reduction at 6 and 18 months after treatment, quality of life (QoL), walking abilities and safety/toxicity. <h3>Results</h3> From January 2018 to October 2019, 84 patients (27 men and 57 women) were included in this study. Mean age at randomization was 56 years (SD 9 years). A total of 130 feet were treated; 65 in each group. Patients in the radiotherapy group had significantly lower mean pain scores compared to patients in the sham-radiotherapy group at 12 and 18 months after the study treatment (p=0.03 and p=0.01 respectively). Pain relief (cumulative complete and partial pain response) at 12 months was 74% for the radiotherapy group and 56% for the sham-radiotherapy group (p=0.002). At twelve months after the end of study-treatment QoL scores in the radiotherapy group improved and were comparable to the score of the Dutch general population. Multilevel testing for QoL scores showed significantly higher QoL scores for the radiotherapy group compared to the sham-radiotherapy group (p<0.001). Moreover, patients from the radiotherapy group had a significantly higher mean walking speed and step rate when walking fast on bare feet (p=0.02). No safety issues related to radiotherapy occurred during and after treatment. <h3>Conclusion</h3> The LedRad-study showed that radiotherapy for symptomatic Ledderhose disease is an effective treatment which results in a significant pain reduction and an improvement of QoL scores and walking abilities, as compared to sham-radiotherapy.

Evaluation of the rehabilitation process after ACL rupture in childhood and adolescence

Problem: Serious knee injuries are gaining epidemiological importance. Especially in childhood, a very significant increase in knee ligament injuries, in particular ACL ruptures, can be observed. In Saxony alone, more than 70 ruptures of the anterior cruciate ligament occur each year as a result of accidents during physical education (PE). Six months after surgery, the students are normally classified as fully fit for sports and are allowed to participate in PE without restrictions. However, the number of reinjuries is very high which limits the quality of life of those affected in the long term and places a heavy financial burden on insurance companies. Methods: Therefore the status quo in the rehabilitation of schoolchildren after ACL rupture was assessed using a multilevel test battery and taking into account known risk factors such as gender, motor competence and BMI. Results: The results show that there are large interindividual differences in the funktional outcomes as well as a large discrepancy between rehabilitation status and return to physical education. Discussion: In order to effectively manage the process of rehabilitation and return to school sports, individual information is necessary in the multimodal setting. To this end, all those involved should be sensitized and trained. Key Words: Knee Injury, Return-to-Sport, Biomechanics of Sports, Prevention, School Sports

Multi-Level Testing Approach for Multi-Agent Systems

The software development cycles need product testing. There is a crucial lack in testing phases of multi-agent systems. To this end, a call for an investigation of appropriate testing techniques is necessary to provide adequate software development processes and supporting tools. Among all existing solutions of the test, the model-based testing technique –MBT) has gained attention with the popularization of models both in software design and development. This technique uses a so-called abstract test model to generate abstract test cases. After their concretization, concrete test cases are submitted to the system under test. The systems outputs are finally compared to the abstract test model expected results. In this context, a model-based testing approach for multi-agent systems based on the Reference net paradigm is proposed in this paper. A running example supported by a multi-agent testing prototype, which aims at simplifying and providing a uniform and automated way for multi-agent systems testing is presented and discussed.