• Title/Summary/Keyword: Long Life Test

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Cryogenic Susceptibility Test for Long-term Storage of Tree Seed Genetic Resources (수목유전자원 종자의 장기저장을 위한 초저온 민감성 검정)

  • Kim, Min-Geun;Kang, Won-Sik;Kim, Du-Hyun;Woo, Kwan-Soo;Ku, Ja-Jung
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2019.04a
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    • pp.82-82
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    • 2019
  • 종자은행은 종자를 보존하는 가장 경제적이고 효율적인 보전방법이지만, 수종에 따라 저장특성의 차이가 커서 수종별 저장방법의 확립이 필요하다. 초저온저장 방법은 세포 분열, 대사 작용을 정지 상태로 유지하므로 현재까지 장기간 보존을 위한 비용이 효율적이며 안정적인 방법이다. 공시재료는 멸종위기 야생식물 등 22종을 대상으로 하였다. 액체질소에 7일간 종자를 침지한 후 $37^{\circ}C$ 항온수조에서 10분간 해동하였다. 휴면이 있는 수종은 파종 전 종자를 저온습윤 하였고, 저온습윤 처리 후에도 휴면타파 되지 않는 수종은 농황산, 지베렐린을 개별 또는 혼용으로 처리하였다. 발아 및 유묘 평가는 $25^{\circ}C/20^{\circ}C$(광12h/암12h)조건에서 진행하였으며, 매일 28일차까지 발아조사를 수행한 후 평가하였다. 진달래속의 꼬리진달래와 철쭉이 초저온 민감성을 보였으며, 오리나무속의 물오리나무, 사방오리는 부분 민감성을 보였다. 민산초나무는 지하부건물중이 유의하게 감소한 결과를 보였으며, 이외의 수종은 초저온 민감성을 보이지 않았으므로 장기보존을 위한 초저온 동결보존이 가능한 것으로 보였다.

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Comparison Analysis of Foot Pressure Characteristics during Walking in Stroke and Normal Elderly (뇌졸중 고령자와 정상인의 보행 시 족압 변화 및 비교 분석)

  • Jung, NamKyo;Park, Se Jin;Kwon, Soon-Hyun;Jun, Jongarm;Yu, Jaehak
    • Journal of Platform Technology
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    • v.9 no.3
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    • pp.36-43
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    • 2021
  • Stroke disease is one of the leading causes of death worldwide, and in particular, it is the most important causative disease that causes disability in the elderly. Since stroke disease often causes death or serious disability, active primary prevention and early detection of prognostic symptoms are very important. In particular, it is necessary to detect and accurately predict stroke prognostic symptoms in daily life and prompt diagnosis and treatment by medical staff. In recent studies, image analysis such as computed tomography (CT) or magnetic resonance imaging (MRI) is mostly used as a methodology for predicting prognostic symptoms in stroke patients. However, this approach has limitations in terms of long test time and high cost. In this paper, we experimented with clinical data on how stroke disease affects foot pressure in elderly in walking. Experiments have shown that there is a significant difference in * p < .05 in 12 cells between the stroke elderly and the normal elderly during walking. As a result, it is significant that we found a significant difference in the gait patterns in daily life of the stroke elderly and the normal elderly.

Couples relationship education program research in Korea: An analysis of program development in human ecology journals (국내 커플관계교육 연구의 프로그램 개발과정 분석: 생활과학분야 학술지 논문을 중심으로)

  • Park, Jisoo;Lee, Jeenkyoung;Lee, Jaerim
    • Journal of Family Relations
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    • v.22 no.4
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    • pp.81-105
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    • 2018
  • Objective: The purpose of this study was to analyze how couples relationship education (CRE) programs in Korean scholarly journals have been developed since they first appeared in 1994. Method: We selected articles that were published in journals related to human ecology and that included information about how the authors developed CRE programs (premarital education, marriage education). Using coding schemes based on the theoretical frameworks of CRE, we quantitatively coded programs in four specific areas: (a) overall characteristics, (b) program planning, (c) program construction and implementation, and (d) program evaluation. Results: Although CRE programs have increased and evolved since the 1990s, the literature has been limited on testing long-term program efficacy, developing dissemination plans, and applying theories to program design. In terms of program participants and content, most programs had similar themes despite their differences in the target audience. We also found that few programs have been provided for diverse couples. As for evaluation, pre- and post-testing was the most common method of efficacy test. Conclusion: Our findings suggest that family researchers and practitioners develop more elaborate and systematic programs to advance CRE in Korea as a core topic of family life education and to provide evidence-informed practice.

Effects of Temperature and Stress Ratio on Low-Cycle Fatigue Crack Growth of G91 Steel (G91강 저주파 피로균열 성장에 미치는 온도와 응력비의 영향)

  • Kim, Jong Bum;Hwang, Soo-Kyung;Kim, Bum Joon;Lee, Jong Hoon;Park, Chang Gyu;Lee, Hyeong Yeon;Kim, Moon Ki;Lim, Byeong Soo
    • Korean Journal of Metals and Materials
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    • v.50 no.4
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    • pp.271-279
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    • 2012
  • 9-12% Cr steels have been used in thermal power plants which repeat start and stop operations. Major factors of fatigue life are temperature, frequency, stress ratio, holding time, microstructure, and environment. Normally, fatigue life decreases at high temperature, low frequency, high stress ratio, and long holding time conditions. A Mod.9Cr-1Mo steel, called G91, was developed at ORNL (Oak Ridge National Laboratory, USA) and was adopted as a high-temperature structural material in the ASME Code in 2004. However, its low-cycle fatigue and fatigue crack growth characteristics have been rarely studied. In this work, we have investigated the low-cycle fatigue crack growth behaviors of G91 steel under various test conditions in terms of temperature and stress ratio. As temperature and stress ratio increase, the crack growth rate becomes faster and striation distance also increases. On the other hand, the number of branch cracks decreases.

The effect of an oral exercise program including whole-body exercises on the mental health of the elderly (전신체조를 병행한 입 체조 프로그램이 노인의 정신건강에 미치는 영향)

  • Jung, Eun-Seo;Seo, Su-Yeon;Lee, Kyeong-Hee
    • Journal of Korean society of Dental Hygiene
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    • v.22 no.1
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    • pp.21-28
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    • 2022
  • Objectives: This study investigated the influence of oral exercise programs with whole-body exercises on the mental health of the elderly. Methods: Elderly individuals aged 65 years or older were assigned to an experimental group and a control group. Oral exercises with whole-body exercises were conducted in the experimental group for 40 minutes, twice weekly, during 5 weeks from May to June 2021. To evaluate the effectiveness of the program, the oral health related quality of life (OHIP-14, GOHAI), mental health, happiness, and social support of the elderly were explored both before and after the execution of the program in the experimental group. A paired sample t-test was performed to check the changes in the factors investigated, both before and after the execution of the program in the two groups. Results: The values of difference between the experimental and control group were compared in relation to the dependent variables, before and after the execution of the oral exercise program with the whole-body exercises. It was found that statistically significant differences in the OHIP-14 (p=0.163), GOHAI (p=0.156), and feelings of happiness in the elderly (p=0.280) were not evident in the experimental group. However, statistically significant differences emerged with regard to the mental health and provision of social support of the elderly (p<0.05). Conclusions: It was found that the oral exercise program with whole-body exercises executed in this study were effective in improving the mental health and social support of the elderly. However, no significant differences were shown in oral health relating to quality of life and feelings of happiness. It is considered that these findings need to be verified by means of future long-term studies.

Regional Distribution Aspect of Swans(Cygnus spp.) in the Nakdong River Downstream Area from October 2013 to September 2018, Busan, R. O. Korea (낙동강하류역에서 2010년 중반기 고니류(Cygnus spp.)의 권역별 서식 현황)

  • Soon-Bok Hong;Ji-Pyo Hong
    • Journal of Environmental Science International
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    • v.32 no.8
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    • pp.533-542
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    • 2023
  • Understanding the regional distribution of swans in the lower Nakdong River area is also important for the continuous habitat of swans according to changes in the surrounding environment of the area. This study was conducted to understand the regional distribution aspect of swans (Cygnus spp.) downstream of the Nakdong River, Republic of Korea, from October 2013 to September 2018. In the estuary, a small ship was used to move along a certain route and observe it with the naked eye or binoculars, and in the land area, Line transect census and Point census method were conducted in parallel. During this period, two species and 34,647 individuals of swans were observed, including 34,356 Whooper Swans (Cygnus cygnus) and 291 Tundra Swans (Cygnus columbianus). The average number of individuals observed in 15 different areas was 1172, 103, 214, 1825, 1850, 13, 318, 1, 0, 1, 11, 21, 5, 0, and 239 respectively. The total average of the number of individuals in these areas was 384.76. The numbers differed significantly among the survey areas (Kruskal-Wallis test, X2=4349.01, P < 0.001). Particularly, the numbers were larger in Eulsukdo, Lower Eulsukdo, and Daemadeung than in the other regions. In conclusion, as long-term survey data, it can be used as basic data to analyze the distribution of swans due to environmental changes caused by the development of the Nakdong River, predict changes in the habitat status of migratory birds, and prepare measures necessary for preservation.

A Study on Maewoldang, Kim Si-seup's Maniac Tendency (매월당(梅月堂) 김시습(金時習)의 '광자(狂者)' 성향에 관한 연구)

  • Jo, Min-hwan
    • Journal of the Daesoon Academy of Sciences
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    • v.35
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    • pp.331-358
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    • 2020
  • This paper is a study of Kim Si-seup's maniacal tendency. The properties of mania can be divided into two categories. One is mental mania wherein the mind has fallen into madness, and the other is morphological mania wherein madness is revealed in real world actions. This thesis analyzes two aspects of the madness of Kim Si-seup, who showed madness in the morphological dimension as well as madness of the mind in the Joseon Dynasty. One notion that is analyzed is 'Longing to never return', and the other is 'To live in obscurity, yet practice wonders.' Kim Si-seup was a promising talent when he was young and was a so-called "infant prodigy." However, when 'Saejo' took the throne of 'Danjong,' he left the house on the road to 'burn all the books' and became a monk as a way of disappearing from the world. Thereafter, Kim Si-seup gave up on the test to become a bureaucrat and lived in hiding while doing strange things while he falsely pretended to be "crazy." He never felt regret hearing others describe him as a strange person. He lived a life of not returning to the mundane world for a long time as he traveled through famous mountains and streams. Also, he pursued a life in 'the world outside the world' without any greed. Sometimes he expresses his own free spirit and madness through poetry with 'what he talks about' and 'wonderful words.' This life was far from a form of neutralization aesthetics achieved by pursuing a 'gentle and magnanimous' life as claimed by Confucian scholars. Kim Si-seup, sometimes referred to as 'a maniac with mental clarity,' directed his efforts at 'false maniacal behavior,' 'weird behavior,' 'life pursuing the world outside the world,' and 'life of breaking off one's relationship with the world.' This maniac-like life of Kim Si-seup was not crazy but conveyed a deep desire to criticize the absurd reality of Joseon society at the time. Regarding Kim Si-seup, Li Hwang criticizes him for wishing 'to live in obscurity yet practice wonders.' Unlike Li Hwang, Yi Yi, who wrote The Records of Kim Si-seup when commissioned to do so by Sun Jo, positively evaluated Kim Si-seup as "a Confucian who followed Buddhism." Although the contents of these evaluations of Kim Si-seup were different, both agreed that Kim Si-seup was a maniacally-oriented individual. Kim Si-seup, who was mentally maniacal and morphological maniacal, represents a unique case in the study history of the Joseon Dynasty, wherein the 'the doctrines of Zhu Zi' exerted great influence.

Long-Term Effects of the DHA Supplementation on Physical and Brain Development in Full-Term Infants (장기간에 걸친 DHA 보충이 영아의 신체발육 및 두뇌발달에 미치는 영향)

  • 정현주
    • Journal of Nutrition and Health
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    • v.31 no.8
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    • pp.1295-1306
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    • 1998
  • Recent research indicates that the n-3 fatty acid , docosahexaenoic acid(22 : 6n 3, DHA) plays an essential role in infant brain development . DHA is highly concentrated in brain and retinal tissues and accumulates during late fetal and early neonatal life. Diets deficient in DHA are associated with reduced levels of DHA in brain and retinal tissues. The purpose of this study is to investigate the long term effects of DHA supplementation on the growth and mental development of full-term infants. THirty four healty infants were recruited from those who were delivered at Kyung Hee Medical Center. The experimental groups were the breast milk+DHA(-) group who were fed human milk for 20 weeks after birth and thereafter were fed placebo formula for 28 weeks, the breast milk+DHA(+) group who were fed human milk for 20 weeks after birth and thereafter were fed DHA supplemented formula for 28 weeks, DHA(-) group who were fed placebo formula for 48 weeks, and DHA(+) group who were fed DHA supplemented formula for 48 weeks. The daily average intake of DHA for the breast milk+DHA(-) , breast milk+DHA(+), DHA(-) and DHA(+) groups were 39.1mg, 89.9mg, 17.7mg, and 160.224mg, respectively. The results showed that measurements of infant weight, length, head, and chest circumferncewere all in normal range and they were not influenced by the DHA supplements in their diets. There was a significant correlation between dietary DHA intake and erythrocyte DHA level. The results of flash visual evoke potential (VEP) test were not correlated with eerythrocyte DHA and dietary DHA levels at 48 weeks of age. No differences were found in Bayley mental and Psychomotor Development lndex scores among the four experimental groups at 48 weeks of age. Unlike the short-term effects there was no long-term effect of relatively small amounts of dietary DHA supplements on the scores for flash VEP and Bayley test, even thour호 there was an elevated DHA supplements on the scores for flash VEP and Bayley test, even through there was an elevated DHA content in the infants erythrocytes.

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Study on Permeability, Optimum Yield and Long-term Stability in Alluvial Well with Filter Layer Change (충적우물에서 필터층 변화에 따른 투수특성, 적정양수량 및 장기적 안정성에 대한 연구)

  • Song, Jae-Yong;Lee, Sang-Moo;Choi, Yong-Soo;Kim, Ki-Joon;Jeong, Gyo-Cheol
    • The Journal of Engineering Geology
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    • v.28 no.1
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    • pp.101-115
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    • 2018
  • This study was carried out to evaluate the effects of various filter conditions on unconfined aquifer (alluvial aquifer). We made model test device which has filter layer, pumping well and observation well which consist of sand layer and gravel layer to test. Step drawdown test and long term pumping tests were carried out using the device. The permeability characteristics of each test group were confirmed and the optimal yield was calculated. As a result of comparing the optimal yield of double filter and single filter in sand, dual-filter SD-300 was valued at 216.8 % higher final optimal yield than single-filter SS-300. Comparing the dual filter SD-300 and the single filter SS-100 with a thin filter layer, dual-filter SD-300 was valued at 709.2% higher final optimal yield than single-filter SS-300. As a result of analysis of optimal yield change over time, It was confirmed that the ratio of optimal yield of single filter and dual filter increase over time. In order to evaluate the long-term change in water intake efficiency, we considered the point at which the initial optimal yield was reduced by 50%. The dual filter SD-300 is about 351.1% higher than SS-300, which is the same thickness filter, and about 579.0% higher than SS-100. From these results, Assuming that the point at which the initial quantity of water intake is reduced to 50% is the well life, double filters are expected to increase their lifespan by about 3.5 times over single filters of the same thickness and by about 5.8 times over typical single filter. These results can be used to design wells to river bank filtration or filtered seawater. In addition, it is possible to clarify the effect of the double filter through the comparison with the future field test results.

The Effect of using Computer & Smart-phone on Decreased Work Efficiency due to Musculoskeletal Disorders ; Mediating Effect of Perceived Musculoskeletal Disorders (컴퓨터 및 스마트폰 사용이 근골격계질환으로 인한 업무능력 저하에 미치는 영향 : 근골격계 질환의 매개효과)

  • Park, Jong-Ho
    • Journal of Distribution Science
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    • v.14 no.3
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    • pp.55-62
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    • 2016
  • Purpose - Average using time of smart-phone for Korean people is 3 hours 39 minutes and most people who are using a computer at home and their workplace can be affected over force to neck and shoulder due to unstable body posture. musculoskeletal disorders which caused by unstable body posture can affect strongly to decrease work efficiency. So this research is designed to measure the effect of using computer & smart-phone on decreased work efficiency due to musculoskeletal disorders and mediating effect between decreased work efficiency and musculoskeletal disorders. Research Design, Data, and Methodology - The author has developed a questionnaire with 6 hypothesis on the basis of previous research result with 5 constructs. The questionnaires were also made by interview and E-mail. 300 copies of questionnaires were distributed and 282 questionnaire were used for the analysis as valid data responses. SPSS ver.21.0 were used and made Cronbach's α and reliability test, correlation, Baron & Kenny 3 step mediated regression analysis. Result - Cronbach's α shows 0.770~0.954 and C.R. is 0.963~0.997 which is higher than 0.7. and AVE was 0.867~0.933. So the data are all acceptable condition. Using for a long time of a computer & smart-phone has a positive effect on musculoskeletal disorders. This means, it can cause musculoskeletal disorders if people use a computer & smart-phone for a long time due to unstable body posture. And musculoskeletal disorders can effect strongly decrease work efficiency. This study also found out that a long time of using computer can cause musculoskeletal disorders rather than using smart-phone a long time. To check mediate effect of musculoskeletal disorders between using a computer & smart-phone and Decreased Work Efficiency, author used 3-step mediated regression analysis of Baron & Kenny (1986). Using a computer for a long time mediate partially and using a smart-phone for a long time mediate completely. This means that using a smart-phone a long time is not the actual reason to decrease work efficiency. But using level of smart-phone is increasing rapidly day by day. So we need to make additional research about this matter seriously. Conclusion - Nowadays, people can not live on without a computer & smart-phone even a moment. But, using a computer for a long time will affect to cause musculoskeletal disorders and it will effect strongly to decrease work efficiency. Before, we thought over that musculoskeletal disorders were diseases of elder people. But, we found out from this study that musculoskeletal disorders can be happen to any people, even children, or workers in heavy industry or engaged in brain work. So we need to be careful when we use a computer for a long time. People also need to be careful to keep correct body posture when using both a computer and smart-phone since a smart-phone became more popular and using time level became longer. Due to increased income and living standard of people, physical growth of young people is so rapid. But the physical environment of society is not suitable for them since it can not follow up the speed of growth. Suitable work table is very important to prevent musculoskeletal disorder which can affect decrease work efficiency. For a person, a society or country, increased productivity is very important since it can directly connected to the job satisfaction. Education and reeducation for the people is also important, but to teach them how to keep good condition of health will be more important since it can increase the quality of work efficiency and quality of life. Computer and Smart-phone is one the best invention of modern society, but it can cause mental and physical disease which can affect decrease work efficiency and productivity. So it is necessary to observe attentively for the situation continually.