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71.
In this paper, we present a case study on the production planning and inventory system in a company manufacturing personal computer (PC) parts. In the case study, the targets are specified for developing a system for production planning and inventory control. The current state of the company is analysed for clarifying the points necessary to achieve the targets. Also, a system based on the analysis is proposed and its effects are estimated. 相似文献
72.
Happiness is considered one of the goals of individuals and nations. Thus, many interdisciplinary efforts have attempted to determine the factors that lead to happiness. However, most of these efforts have ignored some important but less tangible factors, such as having a free press and a healthy environment. In this study, we argue that press freedom—a measure of social capital—along with human and built capital, and natural capital, predicts levels of life satisfaction across nations. Using data from 161 countries, our study provides empirical support to our theoretical model that forms of capital do not influence life satisfaction separately but are actually situated in a web of interrelationships. This is consistent with the assumptions that the road to happiness is not direct. It is a complex path where different forms of capital influence one another before leading to a happy life. 相似文献
73.
Akito Yoshiko Aya Tomita Ryosuke Ando Madoka Ogawa Shohei Kondo Akira Saito Noriko I. Tanaka Teruhiko Koike Yoshiharu Oshida Hiroshi Akima 《European review of aging and physical activity》2018,15(1):13
Background
Older individuals have been shown to present muscle atrophy in conjunction with increased fat fraction in some muscles. The proportion of fat and connective tissue within the skeletal muscle can be estimated from axial B-mode ultrasound images using echo intensity (EI). EI was used to calculate the index of muscle quality. Walking, home-based weight-bearing resistance training, and its combinations are considered simple, easy, and practical exercise interventions for older adults. The purpose of this study was to quantify the effects of walking and walking with home-based resistance training on muscle quality of older individuals.Methods
Thirty-one participants performed walking training only (W-group; 72?±?5?years) and 33 participants performed walking and home-based resistance training (WR-group; 73?±?6?years). This study was a non-randomized controlled trial with no control group. All participants were instructed to walk 2 or 3 sets per week for 10?weeks (one set: 30-min continuous walking). In addition, the WR-group performed home-based weight-bearing resistance training. EI was measured as a muscle quality index using axial B-mode ultrasound images of the rectus femoris and vastus lateralis of the mid-thigh. We further averaged these parameters to obtain the EI of the quadriceps femoris (QF). Participants further performed five functional tests: sit-ups, supine up, sit-to-stand, 5-m maximal walk, and 6-min walk.Results
QF EI was significantly decreased in both groups after training (W-group 69.9?±?7.4?a.u. to 61.7?±?7.0?a.u., WR-group 64.0?±?9.5?a.u. to 51.1?±?10.0?a.u.; P?<?0.05), suggesting improved muscle quality. QF EI was further decreased in the WR-group compared with the W-group. The sit-up test in both groups and the sit-to-stand and 5-m maximal walk tests in the W-group were significantly improved after training.Conclusion
These results suggest that training-induced stimulation is associated with a decrease in EI in some thigh regions. Furthermore, the addition of home-based resistance training to walking would be effective for a greater reduction of EI.74.
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76.
Tatsuya Kubokawa Mana Hasukawa Kunihiko Takahashi 《Scandinavian Journal of Statistics》2014,41(2):394-413
Empirical Bayes (EB) estimates in general linear mixed models are useful for the small area estimation in the sense of increasing precision of estimation of small area means. However, one potential difficulty of EB is that the overall estimate for a larger geographical area based on a (weighted) sum of EB estimates is not necessarily identical to the corresponding direct estimate such as the overall sample mean. Another difficulty is that EB estimates yield over‐shrinking, which results in the sampling variance smaller than the posterior variance. One way to fix these problems is the benchmarking approach based on the constrained empirical Bayes (CEB) estimators, which satisfy the constraints that the aggregated mean and variance are identical to the requested values of mean and variance. In this paper, we treat the general mixed models, derive asymptotic approximations of the mean squared error (MSE) of CEB and provide second‐order unbiased estimators of MSE based on the parametric bootstrap method. These results are applied to natural exponential families with quadratic variance functions. As a specific example, the Poisson‐gamma model is dealt with, and it is illustrated that the CEB estimates and their MSE estimates work well through real mortality data. 相似文献
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79.
Fumiki Takahashi 《Researches on Population Ecology》1976,18(1):235-242
A heterogeneous life cycle of individuals in a population was examined on its adaptive significance to an unstable environmental
condition. The trend of population growth was simulated by a simple mathematical model in which a part of population in a
certain generation was carried over to the next generation without participating in the reproduction.
With the increase of the rate of carryover of individuals to the next generation the population fluctuation tended to be stabilized.
A minute fraction of population is carried over, the effect is very large to prevent the population decline at a sequence
of adverse environmental conditions. The population level increased greatly depending upon the extent of environmental change
as far as the rate of carryover took an intermediate value. The optimum proportion of members to be carried over to the next
generation was determined by the extent of environmental change and its frequency of occurrence. 相似文献