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Showing 73–84 of 142 results

  • A Medical Training System Using Augmented Reality: Trial Development of Environment Platform

    Open Access

    Abstract: A medical training system using augmented reality, AR is presented in this paper. Recognizing an AR marker through a Web camera, computer generated images appear on a real place. We prepared 3D (three-dimensional) anatomical objects to show, and evaluated our system using AR platform. It was found from the experimental result that our system overlaid the digital information of the 3D anatomical objects on the operator’s surrounding real world appropriately, and that feature of visible/invisible objects was verified in AR environment platform.

  • Making protein-protein interaction prediction more reliable with a large-scale dataset at the proteome level

    Open Access

    Abstract: Reliable information about protein-protein interactions (PPIs) enables us to better understand biological processes, pathways and functions. However, there are many experimental problems in identifying complete PPI-networks in a cell or organism. To supplement the limitations of current experimental techniques, we have previously proposed PSOPIA, a computational method to predict whether two proteins interact or not (http://mizuguchilab.org/PSOPIA/) [1]. In the PPI prediction, the selection of datasets is a big issue for accurately evaluating the performance of different algorithms [2, 3]. It is generally believed that increasing the size and diversity of examples makes the dataset more representative and reduces the noise effects; however, for many algorithms, it is impractical to use a large-scale dataset because of the memory and CPU time requirements. In this study, PSOPIA was retrained on a highly imbalanced large-scale dataset having a diverse set of examples at the proteome level. The dataset consisted of 43,060 high-confidence direct physical PPIs obtained from TargetMine [4] (as PPIs being only 0.13% of the total) and 33,098,951 non-PPIs. As a result, the new prediction model achieved a higher AUC of 0.89 (pAUCFPR≤0.5% = 0.24) than the previous model of PSOPIA. Furthermore, it was applied to the problem of filtering out protein pairs incorrectly labeled as interacting from a low-confidence human PPI dataset. Here, we suggest that a diverse set of large-scale examples is key to more reliable PPI prediction, demonstrating the performance of PSOPIA at the proteome level.

  • Automatic Diabetic Retinopathy Screening Based on Morphological Operation and Support Vector Machine Integration

    Open Access

    Abstract: Diabetic retinopathy is one of the most frequent causes of blindness due to diabetes. Primary screening is essential due to prerequisite step toward the diagnosis of diabetic retinopathy in order to prevent vision loss or blindness. This paper presents the methods to discriminate between healthy images and diabetic retinopathy images on the retinal images. The proposed method involves three main steps. Initially, the image is preprocessed to remove small noises and enhance the contrast of the image. Secondly, Kirsch edge detection is utilized to detect the bright lesions. Subsequently, the red lesions are detected depending on top-hat morphological filtering methods. Then the bright and dark lesions are combined by using logical AND operator. In order to be left only pathological signs, the noises near the vicinity of the optic disc and blood vessels are further removed using blob analysis. Finally, morphological features are extracted and fed to the SVM classifier. The proposed method was evaluated with three datasets containing 229 images. It achieved the accuracy of 90%, sensitivity of 86.33% and specificity of 98.55% with the average computational time 8 seconds per image. The method is simple and fast, easy to implement and the result is promising.

  • Accuracy verification of knife tip positioning with position and orientation estimation of the actual liver for liver surgery support system

    Open Access

    Abstract: We are developing a surgical support system for liver abdominal surgery to prevent surgical accidents. Our support system can detect proximity of certain body parts and can make a warning when the knife approaches the critical part to be excised, such as large blood vessels. The system has two distance cameras with different features, and these cameras are located above the operating table. One camera measures the liver shape and the other tracks the position of a surgical knife during surgery. In this report, to evaluate the accuracy of the distance between the position of the knife tip and the position of the blood vessels, the position and orientation of the liver were estimated using depth images of mock liver and virtual liver by simulated annealing algorithm, and the distance between the knife tip and the blood vessel in the mock liver was measured. The experimental results showed the maximum average error of the measured distance was 5.76 mm.

  • Deep Learning based Handwritten Digit Recognition

    Open Access

    Abstract: Neural network and depth learning have been widely used in the field of image processing. Good recognition results are often required for complex network models. But the complex network model makes training difficult and takes a long time. In order to obtain a higher recognition rate with a simple model, the BP neural network and the convolutional neural network are studied separately and verified on the MNIST data set. In order to improve the recognition results further, a combined depth network is proposed and validated on the MNIST dataset. The experimental results show that the recognition effect of the combined depth network is obviously better than that of a single network. A more accurate recognition result is achieved by the combined network.

  • Water Bloom Warning Model Based on Random Forest

    Open Access

    Abstract: Based on the random forest classification algorithm, a warning model of water bloom is proposed. Using the collected data, Select the water quality, meteorological factors which like Chlorophyll a (Chl-a), water temperature (T), PH, nitrogen and phosphorus ratio (TN:TP), chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP), dissolved oxygen Light (E) and so on as the impact factor and use them establish a warning model for Water bloom. And compared with the prediction accuracy of neural network model and SVM model. The results show that the water bloom warning model is established by using stochastic forest classification algorithm, the prediction accuracy is slightly higher than other algorithms. And the random forest algorithm has the characteristics of high robustness, China good performance, strong practicability can effectively carry out water bloom early warning.

  • EKF based Sliding Mode Control for a Quadrotor Attitude Stabilization

    Open Access

    Abstract: In recent years, the interest in unmanned aerial vehicles (UAVs) has been increasing around the world. These vehicles are used in various applications from military operations to civilian tasks. Quadrotor, also called as a quadcopter, is one of the different types of UAVs. Quadrotor can fly more stable than helicopter and the flight control is more convenient. In UAVs, the most basic and salient point is the attitude control for stability. This paper estimates quadrotor’s attitude by extended Kalman filter (EKF) and presents the design procedure of a sliding mode control (SMC) to focus on stabilization. The performance and effectiveness of the proposed system are verified through a simulation study.

  • Study of detection algorithm of pedestrians by image analysis with a crossing request when gazing at a pedestrian crossing signal

    Open Access

    Abstract: Despite the advancement of information and transportation systems, inconvenient pedestrian crossing buttons remain common. In accordance with intelligent transportation systems (ITS), it is necessary to improve pedestrian crossing systems. Therefore, in this study, the proposed system adopts signal gaze, which is more natural compared to pressing a pedestrian crossing button, as a crossing request. A compact camera is inserted in a traffic light to view the other side of the crosswalk. The image data is analyzed in real time to identify all people who have a crossing request. An algorithm with three detectors using Haar-like feature quantities was developed and an evaluation experiment was conducted, considering three conditions: daytime, nighttime, and shade. The detection rate of crossing requests was 100% within 5 s. Although the detection rate was extremely high, there was a problem of incorrectly detecting non-humans. Therefore, in this research, we evaluated the system when detecting non-humans in order to determine the causes. As a result, it became clear that the detection rate changes rapidly depending on the waiting time for a traffic light and also when crossing the crosswalk; however, the system continues to detect the incorrectly detected background.

  • Emergence of Robust Cooperative States by Iterative Internalizations of Opponents’ Personalized Values in Minority Game

    Open Access

    Abstract: Adolescence is a period in which individuals begin facing some challenging choices. Through these choices, and social interactions with peers, adolescent individuals develop their “personalized values” that are the foundations of  their actions. It is known that the adolescent brains have high plasticity, and that the adolescent brains change dynamically, other than that of an adult brain. This study discusses the type of behavior that emerges from adolescents, as
    well as adult individuals with elevated plasticities. To realize this, we adopt the minority game (MG), which is one of the tasks concerning the choice described above. We implement Elman-nets with different learning rates that express different degrees of the plasticity as the player models in the MG. Our simulation results showed that it is a possibility that robust cooperative states emerge by iteratively internalizing the opponent players’ personalized values among players that have a network of reference relationship, irrespective of their varying degrees of plasticity.

  • A Sanshin Musical Performance Assistive Device for People with Physical Disabilities of the Extremities

    Open Access

    Abstract: This paper describes a sanshin musical performance assistive device for people with physical disabilities of the extremities. Sanshin is an Okinawan three-stringed musical instrument. We had developed portable assistive devices to press strings against board of sanshin and its controllers. In the experiments, some participants played the sanshin using the assistive devices. It was found from the experimental results that two persons with muscular dystrophies could appropriately performed music using the sanshins with the previous assistive devices, and that two able-bodied persons could smoothly and steadily play the sanshins using the improved assistive device with the photoelectric sensor-based controller

  • TDOA based Geolocation using IRLS Algorithm

    Open Access

    Abstract: The geolocation method using the wireless signal processing system is widely used in many industrial areas. The time difference of arrival (TDOA) method is one of the most commonly used geolocation methods. The TDOA signal based geolocation system can estimate the position of a mobile object by using at least three base stations in two dimensional spaces. In geolocation problem, the precise estimation of mobile’s position is the most significant issue.The measurement noise that is contained in measured TDOA data causes the estimation inaccuracy in a mobile  geolocation. In this paper, the objective function that represents the scalar error of position estimation is formulated using the concept of p Lp -norm approximation. Also, we suggest the iterative reweighted least square (IRLS) scheme for minimizing of the objective function. The optimal solution can be obtained using the limited measurement data through the reweighted iteration process of the IRLS scheme.

    Keywords: Geolocation; Time difference of arrival; Iterated reweighted least square; Obtimization
    method

  • Analyzing the Advantages of Utilizing State Representations in a Probabilistic Reversal Learning Task

    Open Access

    Abstract: Cognitive flexibility is the ability to adaptively change behaviors in the face of dynamically changing circumstances. To explore the neural basis and computational account of this ability, a probabilistic reversal learning task was employed as the experimental paradigm. Recent studies suggest that a subject may utilize not only a reward history but also a “state representation” of a task to successfully solve one. However, the specific advantages or impact of state representations in task solving are still not fully understood. In this study, we investigated this matter by computer simulations, in which we used two types of reinforcement learning models, a model with state representations and one without. As a result of the simulations, we found that state representations make a learning agent robust against an increasingly difficult task, especially when the number of sampling time in each state is reduced. Based on the results, we propose a hypothesis for the acquisition process of state representations and discuss the experimental design to test it.