Publications by authors named "Yuji Yamakawa"

Object detection and tracking in camera images is a fundamental technology for computer vision and is used in various applications. In particular, object tracking using high-speed cameras is expected to be applied to real-time control in robotics. Therefore, it is required to increase tracking speed and detection accuracy.

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This paper presents a high-speed skeletonization algorithm for detecting the skeletons of linear objects from their binary images. The primary objective of our research is to achieve rapid extraction of the skeletons from binary images while maintaining accuracy for high-speed cameras. The proposed algorithm uses edge supervision and a branch detector to efficiently search inside the object, avoiding unnecessary computation on irrelevant pixels outside the object.

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Although they have been under development for years and are attracting a lot of attention, vision-based tactile sensors still have common defects-the use of such devices to infer the direction of external forces is poorly investigated, and the operating frequency is too low for them to be applied in practical scenarios. Moreover, discussion of the deformation of elastomers used in vision-based tactile sensors remains insufficient. This research focuses on analyzing the deformation of a thin elastic layer on a vision-based tactile sensor by establishing a simplified deformation model, which is cross-validated using the finite element method.

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Tracking and manipulating deformable linear objects (DLOs) has great potential in the industrial world. However, estimating the object's state is crucial and challenging, especially when dealing with heavy occlusion situations and physical properties of different objects. To address these problems, we introduce a novel tracking algorithm to observe and estimate the states of DLO.

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This paper focuses on the teleoperation of a robot hand on the basis of finger position recognition and grasp type estimation. For the finger position recognition, we propose a new method that fuses machine learning and high-speed image-processing techniques. Furthermore, we propose a grasp type estimation method according to the results of the finger position recognition by using decision tree.

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A 75-year-old woman who had been taking methotrexate presented to our hospital for fever and dry cough. Chest computed tomography showed ground-glass opacity in the upper lobe of the right lung and foreign bodies in the lower lobe of the right bronchus. During bronchoscopy, foreign bodies were removed from the airway.

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In this research, we focused on Human-Robot collaboration. There were two goals: (1) to develop and evaluate a real-time Human-Robot collaborative system, and (2) to achieve concrete tasks such as collaborative peg-in-hole using the developed system. We proposed an algorithm for visual sensing and robot hand control to perform collaborative motion, and we analyzed the stability of the collaborative system and a so-called collaborative error caused by image processing and latency.

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A 78-year-old man with a history of surgical resection for ameloblastoma 31 years earlier visited our hospital for prolonged cough. Chest computed tomography showed multiple nodules in both lungs. Although there was no local recurrence in the mandible, the specimen taken from a transbronchoscopic bronchial biopsy showed recurrent ameloblastoma.

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In this paper, we develop a new sensor network system with a high sampling rate (over 500 Hz) based on the simultaneous synchronization of clock and data acquisition for integrating the data obtained from various sensors. Hence, we also propose a method for the synchronization of clock and data acquisition in the sensor network system. In the proposed scheme, multiple sensor nodes including PCs are connected via Ethernet for data communication and for clock synchronization.

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We propose a 500-frames-per-second high-speed vision (HSV) sensor network that acquires frames at a timing that is precisely synchronized across the network. Multiple vision sensor nodes, individually comprising a camera and a PC, are connected via Ethernet for data transmission and for clock synchronization. A network of synchronized HSV sensors provides a significantly expanded field-of-view compared with that of each individual HSV sensor.

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It is traditionally difficult to implement fast and accurate position regulation on an industrial robot in the presence of uncertainties. The uncertain factors can be attributed either to the industrial robot itself (e.g.

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In this paper, a new measurement method of the rotation angle of a rotor, which is named the 'visual encoder,' was proposed. This method is based on the principles of the vision-based method and the optical encoder, and realized by using a high-speed vision system. The visual encoder shows advantageous features such as non-contact, high-resolution and robustness against the free motion and the fluctuation of the rotation axis.

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Nilotinib, a second-generation tyrosine kinase inhibitor (TKI), has been approved for first-line chronic myeloid leukemia (CML) treatment. The improved clinical response of nilotinib over that of the first generation TKI, imatinib, has been thought to be a result of its high potency of inhibition of BCR-ABL kinase. This study aimed to characterize differences between nilotinib and imatinib in the intracellular accumulation and cytotoxic effect on the CML cell line K562.

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A precise and convenient high-performance liquid chromatography (HPLC) method has been established to assay nilotinib in human plasma. Chromatographic separation of nilotinib was performed on a LiChrosphere(®)100 RP-18(e) column (250 mm×4.0 mm, 5 µm) using a mixture of acetonitrile and 0.

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This study explored the association of 14 single nucleotide polymorphisms in three genes coding for influx transporters (SLC22A1, SLCO1B1, and SLCO1B3), two genes coding for efflux transporters (ABCB1 and ABCG2), and four genes coding for enzymes (CYP2C9, CYP2C19, CYP2D6, and CYP3A5) with the pharmacokinetics of imatinib in Japanese patients with chronic myeloid leukemia. Pharmacokinetic parameters were estimated by a population pharmacokinetic analysis based on 622 plasma samples from 34 patients at steady state. Approximately 4.

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The standard dose of imatinib for the treatment of chronic-phase chronic myeloid leukemia (CML) is 400 mg/day. Some patients receive reduced doses of imatinib because of serious adverse effects. Recently, the effective plasma threshold for trough imatinib levels was demonstrated to be 1,002 ng/mL.

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