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Search Results: 1 - 10 of 2132 matches for " Makoto Komazawa "
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A Study into Blood Flow, Heart Rate Variability, and Body Surface Temperature While Listening to Music  [PDF]
Kenichi Itao, Makoto Komazawa, Hiroyuki Kobayashi
Health (Health) , 2018, DOI: 10.4236/health.2018.102015
Abstract: In this study we examined the relaxing effects of listening to music on a total of 12 women aged from their 20s to their 40s by measuring their blood flow, heart rate variability, and their body surface temperature. As a result, We found that there was a tendency for the volume of blood flow to the fingertips to significantly increase when listening to classical music, but there was a variety of changes in blood flow between each age group for healing music and J-Pop music. When measuring heart rate it was found that the LF/HF value, which is an index for the autonomic nervous system which shows tension and stress, fell significantly when listening to each type of music. Lastly, there was a trend for body surface temperature to rise when listening to classical or healing music, a rise which was particularly significant when listening to healing music. This study shows that a relaxing effect can be expected for all indices when listening to classical music. However, for healing music and J-Pop, personal musical preferences seemed to have an effect and the results were varied.
On Human Autonomic Nervous Activity Related to Behavior, Daily and Regional Changes Based on Big Data Measurement via Smartphone  [PDF]
Makoto Komazawa, Kenichi Itao, Hiroyuki Kobayashi, Zhiwei Luo
Health (Health) , 2016, DOI: 10.4236/health.2016.89088
Abstract: This research uses a large amount of autonomic nervous system data (approximately 100,000 entries) to investigate the relationship between human autonomic nervous activity and behaviors, daily and regional changes. Data were measured via a heart rate variability analysis system that utilizes the camera of smartphones. This system was developed by the authors during previous research. The relations between autonomic nervous system and behaviors, total power and sympathetic nervous activity were found to rise after waking, while during leisure time, the total power rises and sympathetic nervous activity is inhibited. Concerning the relationship between autonomic nervous system and day of the week, it was found that total power decreases from the middle through the latter part of the week (namely, Wednesday, Thursday, and Friday), while it rises on Saturday, while the sympathetic nervous activity is suppressed on Saturday. Regarding the relationship between autonomic nervous system and region, it was found that total power is lower in the Kanto region of Japan than in others. This study also shows statistical proof (using a large amount of measurement data) to ideas held by the public for years. Thus, the data can be considered meaningful to the society, and the authors hope that it helps to improve work-life balance.
On Human Autonomic Nervous Activity Related to Weather Conditions Based on Big Data Measurement via Smartphone  [PDF]
Makoto Komazawa, Kenichi Itao, Hiroyuki Kobayashi, Zhiwei Luo
Health (Health) , 2016, DOI: 10.4236/health.2016.89093
Abstract: This research uses our previously-developed smartphone camera-based heart rate change analysis system to survey the correlation between weather patterns and the autonomic nervous activity across a big data set of approximately 200,000 entries. The results showed a trend in which a significant decrease was seen in sympathetic nervous activity in both males and females—the higher the temperature. In addition, a significant increase was seen in the sympathetic nervous system in both males and females—the higher the atmospheric pressure. Lastly, a significant decrease was seen in the sympathetic nervous system in both males and females—the more precipitation there was. These results accord with prior research and with human biological phenomena, and we were able to use a data set of approximately 200,000 entries to statistically demonstrate our hypothesis. We believe this represents a valuable set of reference data for use in the health care.
Measurement and Evaluation of the Autonomic Nervous Function in Daily Life  [PDF]
Makoto Komazawa, Kenichi Itao, Hiroyuki Kobayashi, Zhiwei Luo
Health (Health) , 2016, DOI: 10.4236/health.2016.810099
Abstract: We developed a smart-phone based system to measure the activities of autonomic nervous system during everyday life. Using commonly marketed smart phones, by touching your fingertips on the phone’s camera over a short time of about 30 seconds, it will detect changes in the brightness of the blood flow and in turn analyze your heart rate variability. By using this system, about 100,000 cases were measured and from this large amount of data regarding heart rate variability, we evaluated the autonomic nervous function in their daily life. As a result, for the correlation between autonomic nervous system and age, we found that as the increase of age, the total power becomes decreased and the sympathetic nervous system tends to increase between thirties and fifties. For the correlation between autonomic nervous system and BMI (Body Mass Index), it is found that in general, the higher the BMI, the lower the total power and the stronger the sympathetic nervous system. In other words, people who are fat are lower about the total power and stronger about the sympathetic nervous system. In addition, for the correlation between autonomic nervous system and one day life, it is found that total power and sympathetic function tend to increase, while as evening approaches, sympathetic function tends to become suppressed.
Long-Term Monitoring and Analysis of Age-Related Changes on Autonomic Nervous Function  [PDF]
Kenichi Itao, Makoto Komazawa, Zhiwei Luo, Hiroyuki Kobayashi
Health (Health) , 2017, DOI: 10.4236/health.2017.92023
Abstract: This study used a small wearable heart rate sensor to monitor the daily autonomic function of 600 subjects from across all age groups over a prolonged period of time. The results indicated that the LF/HF ratio (Heart Rate Variability, LF: frequencies between 0.04 Hz - 0.15 Hz, HF: frequencies between 0.15 Hz - 0.4 Hz) an indicator of balance in the autonomic nervous system, tended to peak for subjects in their 40’s and decline thereafter. This conceivably may be partially due to the causes for concern and stress changing and/or declining for the group aged 50-plus. A decline in diurnal variation of autonomic nervous activity was also exhibited in subjects aged 50 and up, showing a tendency for decline in the function of rising sympathetic nerve activity particularly in the morning. It is conceivable that this stems from a decline in the responsiveness of the autonomic nervous system. Subjects in the 50-plus group furthermore exhibited a tendency for declining variation in autonomic nervous activity between sleeping and waking hours. This phenomenon was consistent with the tendency for there to be a rise in wake after sleep onset coupled with a decline in slow-wave sleep in middle- to old-age.
On Canard Homoclinic of a Liénard Perturbation System  [PDF]
Makoto Hayashi
Applied Mathematics (AM) , 2011, DOI: 10.4236/am.2011.210170
Abstract: The classification on the orbits of some Liénard perturbation system with several parameters, which is relation to the example in [1] or [2], is discussed. The conditions for the parameters in order that the system has a unique limit cycle, homoclinic orbits, canards or the unique equilibrium point is globally asymptotic stable are given. The methods in our previous papers are used for the proofs.
Traffic Dynamics and Congested Phases Derived from an Extended Optimal-Velocity Model  [PDF]
Makoto Watanabe
Engineering (ENG) , 2014, DOI: 10.4236/eng.2014.68048

Dynamics is studied for one-dimensional single-lane traffic flow by means of an extended optimal-velocity model with continuously varied bottleneck strength for nonlinear roads. Two phases exist in this model such as free flow and wide moving jam states in the systems having relatively small values of the bottleneck strength parameter. In addition to the two phases, locally congested phaseappears as the strength becomes prominent. Jam formation occurs with the similar mechanism to the boomerang effect as well as the pinch one in it. Wide scattering of the flow-density relation in fundamental diagram is found in the congested phase.

Employment Protection, Employers’ Hiring Strategies and the Screening Role of Temporary Contracts  [PDF]
Makoto Masui
Modern Economy (ME) , 2016, DOI: 10.4236/me.2016.77080
Abstract: In this paper, we develop a matching model with both permanent and temporary contracts to address situations in which the quality of a match formed by a worker-firm pair is not observable to both workers and firms. The screening and cost-saving aspects of temporary employment contracts are two primary reasons that firms use them, but screening has received little attention in the study of employment protection. We show that increasing dismissal costs decreases job creation and that higher dismissal costs are likely to reduce the hiring threshold for temporary jobs and raise the threshold for permanent jobs. We also examine how changes in dismissal costs affect the average productivity of permanent jobs and discuss the effectiveness of the policy of increasing labour market flexibility by weakening firing restrictions for permanent employment.
On Utilization of K-Means for Determination of q-Parameter for Tsallis-Entropy-Maximized-FCM  [PDF]
Makoto Yasuda
Journal of Software Engineering and Applications (JSEA) , 2017, DOI: 10.4236/jsea.2017.107033
Abstract: In this paper, we consider a fuzzy c-means (FCM) clustering algorithm combined with the deterministic annealing method and the Tsallis entropy maximization. The Tsallis entropy is a q-parameter extension of the Shannon entropy. By maximizing the Tsallis entropy within the framework of FCM, membership functions similar to statistical mechanical distribution functions can be derived. One of the major considerations when using this method is how to determine appropriate q values and the highest annealing temperature, Thigh?, for a given data set. Accordingly, in this paper, a method for determining these values simultaneously without introducing any additional parameters is presented. In our approach, the membership function is approximated by a series of expansion methods and the K-means clustering algorithm is utilized as a preprocessing step to estimate a radius of each data distribution. The results of experiments indicate that the proposed method is effective and both q and Thigh can be determined automatically and algebraically from a given data set.
Theoretical study of lithium clusters by electronic stress tensor
Kazuhide Ichikawa,Hiroo Nozaki,Naoya Komazawa,Akitomo Tachibana
AIP Advances , 2012, DOI: 10.1063/1.4774037
Abstract: We study the electronic structure of small lithium clusters Lin (n = 2 ~ 8) using the electronic stress tensor. We find that the three eigenvalues of the electronic stress tensor of the Li clusters are negative and degenerate, just like the stress tensor of liquid. This leads us to propose that we may characterize a metallic bond in terms of the electronic stress tensor. Our proposal is that in addition to the negativity of the three eigenvalues of the electronic stress tensor, their degeneracy characterizes some aspects of the metallic nature of chemical bonding. To quantify the degree of degeneracy, we use the differential eigenvalues of the electronic stress tensor. By comparing the Li clusters and hydrocarbon molecules, we show that the sign of the largest eigenvalue and the differential eigenvalues could be useful indices to evaluate the metallicity or covalency of a chemical bond.
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