Symbol Emergence in Robotics: A Survey

Humans can learn the use of language through physical interaction with their environment and semiotic communication with other people. It is very important to obtain a computational understanding of how humans can form a symbol system and obtain semiotic skills through their autonomous mental development. Recently, many studies have been conducted on the construction of robotic systems and machine-learning methods that can learn the use of language through embodied multimodal interaction with their environment and other systems. Understanding human social interactions and developing a robot that can smoothly communicate with human users in the long term, requires an understanding of the dynamics of symbol systems and is crucially important. The embodied cognition and social interaction of participants gradually change a symbol system in a constructive manner. In this paper, we introduce a field of research called symbol emergence in robotics (SER). SER is a constructive approach towards an emergent symbol system. The emergent symbol system is socially self-organized through both semiotic communications and physical interactions with autonomous cognitive developmental agents, i.e., humans and developmental robots. Specifically, we describe some state-of-art research topics concerning SER, e.g., multimodal categorization, word discovery, and a double articulation analysis, that enable a robot to obtain words and their embodied meanings from raw sensory--motor information, including visual information, haptic information, auditory information, and acoustic speech signals, in a totally unsupervised manner. Finally, we suggest future directions of research in SER.Comment: submitted to Advanced Robotic

Saari's homographic conjecture for planar equal-mass three-body problem under a strong force potential

Donald Saari conjectured that the $N$-body motion with constant configurational measure is a motion with fixed shape. Here, the configurational measure $\mu$ is a scale invariant product of the moment of inertia $I=\sum_k m_k |q_k|^2$ and the potential function $U=\sum_{i<j} m_i m_j/|q_i-q_j|^\alpha$, $\alpha >0$. Namely, $\mu = I^{\alpha/2}U$. We will show that this conjecture is true for planar equal-mass three-body problem under the strong force potential $\sum_{i<j} 1/|q_i-q_j|^2$

Relationship between ankle plantar flexor force steadiness and postural stability on stable and unstable platforms

[Purpose]This study was aimed at determining the relationship between ankle plantar flexor force steadiness and postural control during single leg standing on stable and unstable platforms.[Methods]For the thirty-three healthy participants, force steadiness, at target torques of 5%, 20%, and 50% of the maximum voluntary torque (MVT) of the ankle plantar flexors, was measured. Force steadiness was calculated as the coefficient of variation of force. Single leg standing on stable and unstable platforms was performed using the BIODEX Balance System SD. The standard deviation of the anteroposterior center of pressure (COP) displacements was measured as the index for postural control. During both measurements, muscle activities of the soleus were collected using surface electromyography.[Results]On the stable platform, the COP fluctuation significantly correlated with force steadiness at 5% of MVT (r = 0.512, p = 0.002). On the unstable platform, the COP fluctuation significantly correlated with force steadiness at 20% of MVT (r = 0.458, p = 0.007). However, the extent of muscle activity observed for a single leg standing on both stable and unstable platforms was significantly greater than the muscle activity observed while performing force steadiness tasks at 5% and 20% of MVT, respectively.[Conclusion]Postural stability during single leg standing on stable and unstable platforms may be related to one’s ability to maintain constant torque at 5% and 20% of MVT regardless of the muscle activity. These results suggest that the required abilities to control muscle force differ depending on the postural control tasks

A Case of Mediastinal Lymph Node Carcinoma of Unknown Primary Site Treated with Docetaxel and Cisplatin with Concurrent Thoracic Radiation Therapy

Mediastinal lymph node carcinoma of unknown primary site is rare and may have a better prognosis if extensive treatment is performed. Case, A 69-year-old-male presented with a persistent cough. Chest computed tomography (CT) demonstrated a large tumor 9.5×8.2cm, in the mediastinum, compressing the right main bronchus, the right pulmonary artery, and the superior vena cava. Because fiberoptic bronchoscopy was insufficient for diagnosis, mediastinoscopic tumor biopsy under general anesthesia was undertaken. Histological examination revealed adenocarcinoma. Extensive examinations revealed no other neoplastic lesion except in the mediastinum. Mediastinal lymph node carcinoma of unknown primary site was diagnosed. The patient was treated with docetaxel and cisplatin with concurrent thoracic radiation therapy. A month after the start of chemoradiotherapy, the mediastinal tumor regressed markedly. The patient remained free of symptoms without regrowth of the primary site. Exploration of the body showed no further abnormalities 20 months after disease onset

Septic Pulmonary Embolism Induced by Dental Infection

Dental infection can be an important source for septic pulmonary embolism (SPE), but only a few cases of SPE accompanying dental infection have been reported. The aim of this study was to characterize the clinical features of SPE induced by dental infection. Patients who fulfilled the diagnostic criteria described in the text were recruited in a retrospective fashion. All 9 patients were men, with a median age of 59 years (range:47 to 74 years). Eight patients had chest pain (88.9%), 5 had a preceding toothache (55.6%) and 3 had preceding gingival swelling (33.3%). Blood cultures obtained from 7 patients were negative. Periodontitis was found in all of the cases, periapical periodontitis in 5 cases, and gingival abscess in 3 cases. The median duration of hospitalization was 15 days, and symptoms were mild in some cases. In addition to antimicrobial therapy, tooth extraction was performed in 3 cases, tooth scaling in 6. SPE induced by dental infection has prominent clinical characteristics such as male preponderance, chest pain, preceding toothache, and mild clinical course

The Effect of Insulin Administration and Antibacterial Irrigation with Chlorhexidine Gluconate on the Disturbance of Periodontal Tissue Caused by Food Impaction in Streptozotocin-Induced Diabetic Rats

福岡歯科大学2015年

Autopsy Case of Bilateral Optic Nerve Aplasia with Microphthalmia: Neural Retina Formation Is Required for the Coordinated Development of Ocular Tissues

Human congenital anomalies provide information that contributes to the understanding of developmental mechanisms. Here we report bilateral optic nerve aplasia (ONA) with microphthalmia in the autopsy of the cadaver of a 70-year-old Japanese female. The gross anatomical inspection of the brain showed a cotton thread-like cord in the presumed location of the optic nerve tract or chiasm. Histologically, no neural retina, optic nerve bundle or retinal central vessels were formed in the eye globe, and the retinal pigment cells formed rosettes. The cornea, iris, and lens were also histologically abnormal. Immunohistochemically, no retinal cells expressed beta III tubulin, and Pax6-immunoreactive cells were present in the ciliary non-pigmented epithelial cells. This case of ONA could be attributed to the agenesis of retinal projection neurons as a sequel to the disruption of neural retina development. The neural retina formation would coordinate the proper development of ocular tissues