Evaluation of a Deep Learning Algorithm for Automated Spleen Segmentation in Patients with Conditions Directly or Indirectly Affecting the Spleen

The aim of this study was to develop a deep learning-based algorithm for fully automated spleen segmentation using CT images and to evaluate the performance in conditions directly or indirectly affecting the spleen (e.g., splenomegaly, ascites). For this, a 3D U-Net was trained on an in-house dataset (n = 61) including diseases with and without splenic involvement (in-house U-Net), and an open-source dataset from the Medical Segmentation Decathlon (open dataset, n = 61) without splenic abnormalities (open U-Net). Both datasets were split into a training (n = 32.52%), a validation (n = 9.15%) and a testing dataset (n = 20.33%). The segmentation performances of the two models were measured using four established metrics, including the Dice Similarity Coefficient (DSC). On the open test dataset, the in-house and open U-Net achieved a mean DSC of 0.906 and 0.897 respectively (p = 0.526). On the in-house test dataset, the in-house U-Net achieved a mean DSC of 0.941, whereas the open U-Net obtained a mean DSC of 0.648 (p < 0.001), showing very poor segmentation results in patients with abnormalities in or surrounding the spleen. Thus, for reliable, fully automated spleen segmentation in clinical routine, the training dataset of a deep learning-based algorithm should include conditions that directly or indirectly affect the spleen.

Student Resource on Newton’s Law Concepts Reviewing from Gender: Identification Using Open-Ended Questions

This article aims to find out the resources activated by students in solving Newton’s laws in terms of gender. This research is a quantitative descriptive study with two open test instruments. This research was conducted on 10th-grade students at SMK N 1 Muaro Jambi with 11 female students and 11 male students. The facts obtained in this study indicate that students’ thinking about Newton’s law is still lacking during the learning process. Based on the analysis results of the level of understanding of student concepts, female students understand better than male students. Overall, students fail to summon relevant knowledge when facing problems in the form of phenomena. In addition, they failed to use the knowledge they gained to answer questions. Students’ abilities are activated when they understand a phenomenon influenced by students’ original ideas from their personal experiences.

A Graph-Based Ant Algorithm for the Winner Determination Problem in Combinatorial Auctions

Iterative combinatorial auctions are known to resolve bidder preference elicitation problems. However, winner determination is a known key bottleneck that has prevented widespread adoption of such auctions, and adding a time-bound to winner determination further complicates the mechanism. As a result, heuristic-based methods have enjoyed an increase in applicability. We add to the growing body of work in heuristic-based winner determination by proposing an ant colony metaheuristic–based anytime algorithm that produces optimal or near-optimal winner determination results within specified time. Our proposed algorithm resolves the speed versus accuracy problem and displays superior performance compared with 20 past state-of-the-art heuristics and two exact algorithms, for 94 open test auction instances that display a wide variety in bid-bundle composition. Furthermore, we contribute to the literature in two predominant ways: first, we represent the winner determination problem as one of finding the maximum weighted path on a directed cyclic graph; second, we improve upon existing ant colony heuristic–based exploration methods by implementing randomized pheromone updating and randomized graph pruning. Finally, to aid auction designers, we implement the anytime property of the algorithm, which allows auctioneers to stop the algorithm and return a valid solution to the winner determination problem even if it is interrupted before computation ends.

Development of pneumatic test rig protection for elements of underwater oil & gas production system

Object and purpose of research. This paper discusses protective structure for a pneumatic test rig intended for experiments with the elements of underwater mining system at KSRC Open Test Tank. The purpose of this study was to justify the design parameters ensuring the safety in case of an emergency leakage from the tested equipment. Materials and methods. The study followed the methods of computer-based simulation to analyse gas dynamics of leakage escalation and its effect upon the protective structure. Main results. This paper presents development results of a floating submersible protective structure, with analytical estimates of hazardous factors and protection robustness in case of a hypothetical emergency during pneumatic tests of equipment. Conclusion. Protective structure design suggested in this paper for given conditions of submerging into an open tank and given conditions of pneumatic tests (pressure 69 MPa, nitrogen volume 1 m3) prevents hazardous leakage to the environment. Accordingly, these tests will be safe for both personnel and test facilities.

Soap bubbles seeding for quantitative time resolved velocity measurements of a turbulent wake flow behind a cylinder

The wake flow behind a cylinder of 100mm diameter is investigated using time resolved 2D PIV technique applied to an air flow generated in a closed loop open test section wind tunnel. The flow is seeded using a micro soap bubble generator (BG-1000, TSI Inc.). The bubbles in the air flow were illuminated with a CW laser source and imaged using a high-speed camera. The main purpose of this study is to show features and advantages of using soap bubbles as seeding for a relatively large-scale PIV investigation under low power illumination conditions.

Quadcopters Testing Platform for Educational Environments

This work focuses on the design and construction of an experimental test bench of three degrees of freedom with application in educational environments. It is constituted by a gyroscopic structure that allows the movements of a quadcopter to analyze the control systems. In this context, the main features of the mechanical and electronic design of this prototype are described. At the same time, the main characteristics with respect to existing platforms are highlighted in aspects such as: system autonomy, cost, safety level, operation ranges, experimental flexibility, among others. The possible controller design approaches for quadcopter stabilization can extend to many basic and advanced techniques. In this work, to show the operation and didactic use of the platform, the development of the controller for tilt angle stabilization under two different approaches are presented. The first approach is through PID control, oriented for undergraduate students with basic level in control theory. The second approach is by means of State Feedback, oriented to students with more advanced level in this field. The result of this work is an open test bench, enabled for the experimentation of control algorithms using Matlab-Simulink.

Composite UHBR Fan for Forced Response and Flutter Investigations

In the CA3ViAR (Composite fan Aerodynamic, Aeroelastic, and Aeroacoustic Validation Rig) project, a composite low-transonic fan is designed and tested. The aim is a scaled ultra-high bypass ratio (UHBR) fan with state-of-the-art aerodynamic performance and composite rotor blades, which features aeroelastic phenomena, e.g. forced response by inlet distortions and flutter, under certain operating points within the wind tunnel. In this paper, the aerodynamic and aeroelastic design process starting from the overall performance specifications to a threedimensional numerical model is described. A target of eigen-frequency and twist-to-plunge ratio is specified such that flutter occurs at desired operating conditions with a sufficient margin with respect to the working line. Different materials and layups of the composite blade are analyzed to reach the structural target. The fan should serve as an open test case to advance the future research on aerodynamic, aeroelastic, and aeroacoustic performance investigations in a wide range of operating conditions. A preliminary fan stage design is presented in this paper.

Data Replication Using Data Mining Techniques

Database Replication is the successive electronic duplicating of information from a database in one PC or server to a database in another with the goal that all clients share a similar dimension of data. The outcome is a conveyed database in which clients can get to information significant to their assignments without meddling with crafted by others. Anyway information replication is an entrancing theme for both hypothesis and practice. On the hypothetical side, numerous solid outcomes requirement what should be possible as far as consistency: e.g., the difficulty of achieving agreement in offbeat frameworks the blocking idea of CAP hypothesis, and the requirement for picking an appropriate rightness foundation among the numerous conceivable. On the pragmatic side, information replication assumes a key job in a wide scope of settings like storing, back-up, high accessibility, wide territory content dissemination, expanding versatility, parallel preparing, and so forth. Finding a replication arrangement that is reasonable in whatever number such settings as could reasonably be expected remains an open test.