Ryugasaki, Japan
Ryugasaki, Japan

Ryutsu Keizai University is a Japanese private university in Ryugasaki, Ibaraki. It was founded in 1965. Wikipedia.

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Goto T.,Ryutsu Keizai University | Yaku T.,Nihon University | Tsuchida K.,Toyo University
Proceedings of the 32nd International Conference on Computers and Their Applications, CATA 2017 | Year: 2017

Many kinds of open source software (OSS) are used to develop software or systems. These software are getting big and complex, developers have to understand them before their development. Such kind of tools to support for understanding source codes are required these days. So far some researches have been done for source code summarization. We have placed great importance on software understanding with diagrams. Program diagrams, many of which have been recently proposed, can enhance the understanding of software or systems but developers cannot properly understand these diagrams without clear notations. Unified Modeling Language (UML) is also used in software development. Package diagram is one of a diagram used in UML. Package diagram plays an important role to design or analyze structures of systems. In this paper, we propose a method to generate annotation for diagrams based on attribute evaluation. Our method based on a formal approach, so we can obtain aesthetic diagrams with annotation automatically. © ISCA, CATA 2017.

Ishii N.,Ryutsu Keizai University
Clinical Physiology and Functional Imaging | Year: 2015

Exaggerated elevation of systolic blood pressure (SBP) during exercise is a risk factor for future cardiovascular disease. Although there are differences between the outdoor exercise and exercise tests in the laboratory setting, there is little information regarding SBP changes during practical outdoor exercise. We investigated SBP changes during self-paced outdoor walking and the relationship to air temperature. Subjects (n = 109, 47-83 years) walked outdoors at their own pace wearing a blood pressure monitor on their wrist. SBP increased during walking compared to rest, but was higher at the 1 km mark than both the 2 and 3 km marks (rest, 124 ± 14 mmHg; 1 km, 140 ± 16 mmHg; 2 km, 136 ± 18 mmHg; 3 km, 135 ± 18 mmHg). SBP at rest, air temperature, body mass index (BMI) and walking intensity during the first 1 km were identified as predictors of SBP at the 1 km mark in the stepwise regression analysis, independent of other confounders (R2 = 0·606). SBP at the 1 km mark was higher in the lower temperature group (11·6-14·3°C, 145 ± 14 mmHg) than in the intermediate (15·1-16·7°C, 140 ± 18 mmHg) and higher (17·0-19·6°C, 136 ± 16 mmHg) temperature groups, independent of SBP at rest, BMI and walking intensity. These results suggest that increases in SBP are higher on lower temperature days and are greater at 1 km than at 2 and 3 km. It is therefore recommended that measures are taken against the cold on lower temperature days to attenuate the SBP response during onset of walking. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine.

Ikawa N.,Ryutsu Keizai University
International Journal of Wavelets, Multiresolution and Information Processing | Year: 2013

The auditory brainstem response (ABR) is widely used as an index to assist hearing and brain function diagnoses. In particular, in clinical applications, the rapid detection of ABR peak characteristics is required. One approach to improving the speed of detection is to decrease the number of signal averaging procedures while denoising during the detection of ABR waveforms; another approach is to extract the characteristics of ABR waveform components. In our previous study, to represent ABR waveform components, we obtained not only the frequency characteristics of an ABR but also the frequency characteristics of each component of the ABR based on the time (latency). Using a one-dimensional discrete wavelet transform (DWT) in this latency-frequency analysis, we described an approximate method of reproducing ABR signals with a low SNR from observed values obtained with a smaller number of averaging procedures. At the same time, using this multiple-level frequency decomposition of ABR signals according to the known frequency content of the ABR, we extracted the peak latency of the fast component of the ABR using fewer averagings of the ABR data. From these decomposition and reconstruction results for ABR signals, we proposed the optimal decomposition level of the ABR and explained how we used the waveform of the ABR reconstructed by the inverse DWT (IDWT). In this paper, we propose a method of automated averaging of the ABR using the waveform reconstructed by discrete wavelet multiresolution analysis (MRA). Our proposed method will be useful for the fast detection of ABR latency characteristics in hearing screening test. © 2013 World Scientific Publishing Company.

Regular exercise improves aging-induced deterioration of arterial stiffness, and is associated with elevated production of pentraxin 3 (PTX3) and anti-inflammatory as well as anti-atherosclerotic effects. However, the time-dependent effect of exercise training on arterial stiffness and PTX3 production remains unclear. The purpose of this study was to investigate the time course of the association between the effects of training on the circulating PTX3 level and arterial stiffness in middle-aged and older adults. Thirty-two healthy Japanese subjects (66.2±1.3 year) were randomly divided into two groups: training (exercise intervention) and sedentary controls. Subjects in the training group completed 8 weeks of aerobic exercise training (60–70% peak oxygen uptake (VO2peak) for 45 min, 3 days per week); during the training period, we evaluated plasma PTX3 concentration and carotid–femoral pulse wave velocity (cfPWV) every 2 wk. cfPWV gradually declined over the 8-week training period, and was significantly reduced after 6 and 8 week of exercise intervention (P<0.05). Plasma PTX3 level was significantly increased after 4 weeks of the intervention (P<0.05). In addition, the exercise training–induced reduction in cfPWV was negatively correlated with the percent change in plasma PTX3 level after 6 week (r=−0.54, P<0.05) and 8 weeks (r=−0.51, P<0.05) of the intervention, but not correlated at 4 weeks. Plasma PTX3 level was elevated at the early stage of the exercise training intervention, and was subsequently associated with training-induced alteration of arterial stiffness in middle-aged and older adults.Journal of Human Hypertension advance online publication, 15 October 2015; doi:10.1038/jhh.2015.105. © 2015 Macmillan Publishers Limited

Ikawa N.,Ryutsu Keizai University | Morimoto A.,Osaka Kyoiku University | Ashino R.,Osaka Kyoiku University
International Conference on Wavelet Analysis and Pattern Recognition | Year: 2012

A new design based on wavelet analysis for the objective audiometry devices is proposed. The auditory brainstem response and 80-Hz auditory steady-state response (ASSR) are used in the objective audiometry devices for infants. For the aged, an objective audiometry device is used in anti-aging investigations, which enables the hearing acuity of awake adults to be tested with the 40-Hz ASSR. The ASSR evoked by an amplitude modulated tone is recorded as a waveform. However, the evoked potential response is very small. Therefore, it is difficult to decide a threshold of the response and whether a significant response exists when it is mixed with noise such as the background brain waves. To cope with this problem, we need to average the evoked response waveforms. In particular, the 40-Hz ASSR has a large amount of noise caused by the background brain waves in comparison with the 80-Hz ASSR. In this paper, we apply waveform analysis using the wavelet transform in order to extract the 40-Hz ASSR from a signal mixed with a large amount of noise. Subjects with normal hearing participated in this study. © 2012 IEEE.

Otsuki T.,Ryutsu Keizai University | Shimizu K.,University of Tsukuba | Iemitsu M.,Ritsumeikan University | Kono I.,University of Tsukuba
Journal of Clinical Biochemistry and Nutrition | Year: 2013

Chlorella, a unicellular green alga, contains various antioxidants and other nutrients such as amino acids and fiber. Previous studies have reported that supplementation with multiple antioxidants reduces arterial stiffness, a well-established cardiovascular risk factor. We investigated the effects of Chlorella intake on arterial stiffness using a single-blinded, placebo-controlled crossover study design. Fourteen young men took placebo or Chlorella tablets for four weeks, with a 12-week washout period between trials, in a randomized order. Before and after each trial, blood pressure, heart rate, and brachial-ankle pulse wave velocity, an index of arterial stiffness, were measured. Treatment compliance was comparable between the two groups. There were no differences in blood pressure and heart rate before and after supplementation in both the placebo and Chlorella groups. Brachial-ankle pulse wave velocity decreased after Chlorella intake (before vs after intake; 11.6 ± 0.2 vs 11.1 ± 0.1 m/s, p = 0.01), but not after placebo intake (11.4 ± 0.2 vs 11.4 ± 0.2 m/s, p = 0.98). Multicomponent analysis of the Chlorella-containing tablet detected nutrients that can reduce arterial stiffness, such as antioxidant vitamins, arginine, potassium, calcium, and n-3 unsaturated fatty acids. These results suggest that intake of a Chlorella-containing multicomponent supplement can decrease arterial stiffness. ©2013 JCBN.

Goto T.,Ryutsu Keizai University | Tsuchida K.,Toyo University
Proceedings of the IEEE International Conference on Industrial Technology | Year: 2016

Many kinds of open source software (OSS) are used to develop software or systems. In order to develop software using existing forms of OSS, developers have to understand them. However some OSS lacks adequate documentation for its source code. Program diagrams, many of which have been recently proposed, can enhance the understanding of software or systems but developers cannot properly understand these diagrams without clear notations. In this paper, will discuss the importance of and principles for annotating package diagrams by analyzing case research and several case studies in this field. © 2016 IEEE.

Miyaki A.,University of Tsukuba | Maeda S.,University of Tsukuba | Otsuki T.,Ryutsu Keizai University | Ajisaka R.,University of Tsukuba
Medicine and Science in Sports and Exercise | Year: 2011

Introduction: Pentraxin 3 (PTX3), which is mainly produced by endothelial cells, macrophages, and smooth muscle cells in the atherosclerotic region, has a cardioprotective effect. Endurance exercise training has also been known to offer cardioprotection. However, the effect of regular endurance exercise on PTX3 is unknown. This study aimed to investigate whether plasma PTX3 concentrations increase in endurance-trained men. Ten young endurance-trained men and 12 age- and gender-matched sedentary controls participated in this study. Methods: We measured plasma PTX3 concentrations of the participants in each group. We also determined systemic arterial compliance (SAC) by using simultaneous M-mode ultrasound and arterial applanation tonometry of the common carotid artery and used HDL cholesterol (HDLC) as an index of cardioprotective effect. Results: Maximal oxygen uptake was significantly higher in the endurance-trained men than that in the sedentary controls. SAC and HDLC were significantly higher in the endurance-trained men than that in the sedentary controls (SAC = 1.74 ± 0.11 vs 1.41 ± 0.09 mL•mm Hg -1, P < 0.05; HDLC = 70 ± 5 vs 57 ± 4 mg•dL, P < 0.05). Plasma PTX3 concentrations were markedly higher in the endurance-trained men than that in the sedentary controls (0.93 ± 0.11 vs 0.68 ± 0.06 ng•mL, P < 0.05). Relationships between plasma PTX3 concentrations and SAC and HDLC were linear. Conclusions: This is the first study revealing that endurance-trained individuals had higher levels of circulating PTX3 than sedentary controls. PTX3 may play a partial role in endurance exercise training-induced cardioprotection. © 2010 by the American College of Sports Medicine.

Otsuki T.,Ryutsu Keizai University | Kotato T.,Ryutsu Keizai University | Zempo-Miyaki A.,Ryutsu Keizai University
American Journal of Physiology - Heart and Circulatory Physiology | Year: 2016

Since aerobic exercise (e.g., walking) and resistance exercise (e.g., lifting objects and mopping) are both parts of the activities of daily living, an exaggerated elevation in systolic blood pressure (SBP) during aerobic and resistance exercise is an early marker of cardiovascular disease. This study investigated the effects of habitual exercise on SBP during lowintensity resistance exercise using both cross-sectional and interventional approaches. First, in 57 normotensive women (61.9 ± 1.0 yr of age), daily physical activity level, as assessed by triaxial accelerometry, was correlated with SBP during resistance exercise at 20 and 40% of the 1 repetition maximum (r = –0.408 and r = –0.348, respectively). Maximal oxygen uptake was correlated with SBP during exercise at 20% (r = –0.385) and 40% (r = –0.457). Physical activity level or maximal oxygen uptake was identified as a predictor of SBP during the exercise in stepwise regression analysis, independent of SBP at rest and other factors (R2 = 0.729-0.781). Second, 66 men and women (64.6 ± 0.9 yr of age) participated in a 6-wk intervention as a part of the training (walking, 4.3 ± 0.3 days/wk, 55.6 ± 4.1 min/day, 70.7 ± 1.2% of maximal heart rate) or control group. SBP during resistance exercise in the training group decreased after the intervention (before vs. after: 20%, 143 ± 4 vs. 128 ± 4 mmHg; and 40%, 148 ± 5 vs. 134 ± 4 mmHg). In the control group, there were no significant differences in SBP before and after the intervention. SBP during resistance exercise after the intervention was lower in the training group relative to the control group. These results suggest that habitual exercise decreases SBP during low-intensity resistance exercise. © 2016 the American Physiological Society.

Twelve weeks of aerobic exercise significantly boosted testosterone levels in overweight and obese men, with the greatest increases seen among vigorous exercisers, according to research presented at the Integrative Biology of Exercise 7 meeting in Phoenix. Researchers from Tsukuba University and Ryutsu Keizai University in Japan previously found that a combination of diet and exercise was effective in increasing the testosterone in this population. For this study, however, they looked specifically at the effect of regular aerobic exercise on testosterone levels. "Testosterone is a male sex hormone, and low circulating testosterone levels lead to various health disorders in men. Obesity, one of the biggest problems in the world, results in reduction in circulating testosterone levels in men," the research team wrote. Fatigue, decreased sex drive and decreases in muscle and bone mass are some of the common symptoms of low testosterone in men. The research team compared 16 normal weight men to 28 overweight/obese men. None of the men were regular exercisers. At baseline, the overweight/obese men had significantly lower total, free and bioavailable testosterone level than normal weight men. All of the study volunteers completed a 12-week aerobic exercise plan that entailed 40-60 minutes of walking or jogging on one to three days per week. Testosterone levels were also recorded at the end of the study. While their testosterone was still at lower levels than the normal weight men at baseline, overweight and obese men saw a significant increase in all measured testosterone levels. This effect was particularly evident among the men who exercised vigorously. However, the exercise intervention had no significant effect on testosterone levels in the normal weight men. Body weight also significantly decreased following the exercise intervention in the overweight/obese cohort. "I think decrease in body mass is one of the factors for increasing serum testosterone levels," said Hiroshi Kumagai, lead researcher on the study. "However, the degree of weight loss is small, and we found that the increase in vigorous physical activity was independently associated with the increase in serum testosterone levels. So, it seems the increase in physical activity, especially vigorous physical activity, is the main factor for increasing serum testosterone levels."

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