Earticle

PURPOSE: This study find out the effect of torque and power through various solidity of mouth guard on shoulder flexion and extension. METHODS: This study was conducted with healthy adults in their 20s Korean. Cybex system was used to measure the torque and power fo shoulder joint flexion/extension during isokinetic contraction when the various solidity mouth guard was used and no mouth guard was used. RESULT: The results of this study were summarized as follows: relative torque and average power was showed significantly difference between non applying mouth guard and applying hard type mouth guard during shoulder flexion and extension at isokinetic contraction. CONCLUSION: The application of hard type mouth guard was increased torque and power in joint of body. which may be clinically useful.

노인의 자녀관계의 영향에 대한 연구는 대부분이 자녀결속력에 초점을 두고 있다. 본 연구는 노인의 자녀와의 관계가 우울 및 삶의 만족도에 미치는 영향을 조사한 것으로 자녀결속력 뿐 아니라 자녀에 대한 부양의무기대, 부모역할만족도 등이 독립변인으로 사용되었다. 또한 노인을 전기노인과 후기노인으로 나누어 연령대에 따른 자녀관련변인의 차이 및 배우자유무에 따른 자녀관련변인의 차이를 검증하였다. 본 연구의 대상은 대구, 경북지역의 노인 237명이며 연령 및 배우자유무에 따른 자녀관련변인의 차이를 비교하기위해 t-test와 카이자승검증을 하였다. 자녀관련변인의 우울과 삶의 만족도에 대한 영향을 파악하기 위해서는 위계적 회귀분석을 각각 사용하였으며 자녀관련변인의 영향정도를 파악하기위해서는 표준화계수인 β를 사용하였다. 회귀분석시 선행연구에 의해 우울과 삶의 만족도에 중요한 영향을 미치는 성별, 배우자유무, 교육수준, 인지건강, 주관적 생활수준 등이 통제변인으로 사용되었다. 연구결과에 의하면 자녀수와 우울은 후기노인이 전기노인보다 유의미하게 높은 것으로 나타났다. 배우자가 있는 노인이 배우자가 없는 노인보다 부모역할만족도가 유의미하게 높게 나타났고 우울은 낮으며 삶의 만족도는 높은 것으로 나타났다. 부모의 역할만족도는 우울을 유의미하게 낮추며 삶의 만족도를 유의미하게 높이고 있다. 그러나 자녀수는 우울을 유의미하게 낮추고 있으며 자녀의 부양의무기대가 높을수록 삶의 만족도는 높은 것으로 나타났다.

Most research about the effect of adult children's family relations focus on the intergenerational solidity. This study examines not only the effect of the intergenerational solidity but also parental expectation about filial responsibility and the satisfaction of parental role on depressive symptoms and life satisfaction. The sample size of this study is 237. To check the difference by age and marital status, t-tests and χ2 were used. To test the effects of adult children's variables about depressive symptoms and life satisfaction, separate hierarchical multiple regressions were used. When using hierarchical multiple regressions, gender, marital status, perceived health and perceived economic status which are important factors of depressive symptoms and life satisfaction are controlled. The research results indicate that there are statistically significant differences between the number of children and depressive symptoms by age. Also, there are statistically significant differences between parental role satisfaction, depressive symptoms and life satisfaction by marital status. The parental role satisfaction affects the depressive symptoms negatively and affects the life satisfaction positively. However, the number of the children only affects the depressive symptom negatively in a statistically significant level. Also, parental expectation of filial responsibility affects the life satisfaction in a statistically significant level.

This paper reports the results of experiments in improving performance of leaf identification system using Principal Component Analysis (PCA). The system involved combination of features derived from shape, vein, color, and texture of leaf. PCA was incorporated to the identification system to convert the features into orthogonal features and then the results were inputted to the classifier that used Probabilistic Neural Network (PNN). This approach has been tested on two datasets, Foliage and Flavia, that contain various color leaves (foliage plants) and green leaves respectively. The results showed that PCA can increase the accuracy of the leaf identification system on both datasets.

Recently the blockchain technology has been actively studied due to its great potentiality. The smart contract is a key mechanism of the blockchain system. Due to the short history of the smart contract, many issues have not been solved yet. One main issue is vulnerability and another main issue is cost optimization. While the vulnerability of smart contract has been actively studied, the cost optimization has been rarely studied. In this paper, we propose two cost optimization methods for smart contracts running on the blockchain system. Triggering a function in a smart contract program code may require costs and it is repeated continuously. So the minimization of costs required to trigger a function of smart contract while maintaining the performance equally is very important. The proposed two methods minimize the usage of expensive permanent variables deployed on the blockchain system. We apply the proposed two methods to three prevalent blockchain platforms: Ethereum, Klaytn and Tron. Evaluation experiments verify that the proposed scheme significantly reduces the costs of functions in the smart contract written with Solidity.

The design of low-solidity vaned diffusers and the effect on the performance of a turbocharger compressor is discussed. The effect of vane number and turning angle was investigated while maintaining a basic design with a leading edge angle of $70^{\circ}$, leading and trailing edge radius ratios of 1.1 and 1.3. All results are compared with those obtained with the standard vaneless diffuser configuration and it was shown that all designs increased and shifted the pressure ratio to reduced flowrates. Despite the low-solidity configuration none of the vane designs provided a broad operating range, and the vane leading edge angle was not main factor that system went into the surge condition. The diffuser of higher trailing edge angle improved the flow range for the compressor to operate at lower flow region.