• Journal of the Korean Society for Heat Treatment
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• v.13 no.2
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• pp.108-114
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• 2000

The effects of heat treatments in Al-Si-Mg alloys on the microstructure and hardness have been investigated by the optical microscope, scanning electron microscope(SEM), and Rockwell hardness tester. The materials of various compositions are melted in a vacuum induction furnace under argon atmosphere. Five different Al alloys are prepared from commercial purity aluminium, magnesium and Al-25Si alloy. Two types of aging treatments are performed: i) Isothermal aging of the specimens at $150^{\circ}C$, $170^{\circ}C$ and $190^{\circ}C$. ii) Pre-aging of the specimens at $60^{\circ}C$, $80^{\circ}C$ and $100^{\circ}C$, and followed by final-aging at $170^{\circ}C$ and $190^{\circ}C$. After the heat treatments, Rockwell hardness are measured with all the specimens.

• International Journal of Industrial Entomology and Biomaterials
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• v.45 no.1
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• pp.1-11
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• 2022

Silkworm pupae, a by-product of the silk industry are known to be valuable resource of nutrients for humans as well as animals besides encompassing diverse bioactive constituents. However, there is a paucity of knowledge on their role in amelioration of oxidative stress and anti-skin aging properties. In the present study, we evaluated the inhibitory effect of aqueous as well as ethanolic (30% and 70%) extracts from distinct stages of male and female silkworm pupae belonging to two silkworm varieties on skin aging-related enzymes. The activities of collagenase, elastase and tyrosinase were effectively inhibited by 70% ethanolic silkworm pupal extracts (SPE), followed by 30% with aqueous extracts exhibiting meager inhibitory potential. SPE were also investigated for their antioxidant activity in oxidative-stressed murine fibroblasts (L929). The intracellular ROS and lipid peroxidation induced by tert-butyl hydroperoxide (t-BHP) in fibroblasts was better attenuated by pre treatment with ethanolic (30%) and aqueous extracts, respectively. The safety of the extracts was determined by studying their effect on fibroblast cell viability and it was found that none of the extracts were cytotoxic. Our findings indicate the potential utility of SPE as anti-aging components in cosmeceuticals.

• Journal of Animal Science and Technology
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• v.63 no.5
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• pp.1169-1181
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• 2021

We investigated the comparative physicochemical attributes, oxidative stability, and microbial characteristics of 28 days dry-aged meat in between boneless sirloin (gluteus medius) and bone-in T-bone steaks (infraspinatus) muscles from Korean Native Hanwoo Steer (KNHS). Results reveal that regardless of the muscles, dry-aging increased protein content and water-holding capacity (WHC) (p < 0.05). Meat from infraspinatus-aged muscle led to darker meat with higher pH values than un-aged meat (p < 0.05). However, fat content, CIE a^*, and CIE b^* remained unchanged in both muscles at aging. At aged meat, thiobarbituric acid reactive substances (TBARS) values from bone-in infraspinatus muscle was 2.5-fold higher than boneless gluteus medius muscle (p < 0.05). Dry-aging led to an increase in the contents of total unsaturated fatty acids (UFAs), monounsaturated fatty acids (MUFAs), and UFA/saturated fatty acids (SFA) in both muscles (p < 0.05). Furthermore, gluteus medius aged muscle concentrated with olic acid (C18:1) compared to infraspinatus aged muscle. Irrespective of the muscles, dry-aging enhanced the total free amino acids (FAAs) as well as tasty, and bitter amino acid contents whereas decreased the tasty/bitter amino acids (p < 0.05). Aromatic amino acid, tryptophan that converted to serotonin was 2-fold higher in boneless gluteus medius muscle than bone-in infraspinatus muscle at pre and post aging processes (p < 0.05). Aged Infraspinatus muscle increased total bacteria (p < 0.05) while no salmonella spp. was detected in both muscles. Taken together, our study confirms that 28 days dry-aging profiling the quality characteristics of boneless sirloin (gluteus medius) and bone-in T-bone steaks (infraspinatus) distinctly while gluteus medius aged steak performs better owing to oxidative stability and functional compounds than infraspinatus aged steak.

• Journal of Families and Better Life
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• v.25 no.1 s.85
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• pp.145-158
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• 2007

The purpose of this study was to elicit the multi-dimensions of retirement expectations, and explore sub-factors of retirement expectations which predict the possibility of worker's participation to each pre-retirement planning programs. The major findings were as follows: first, this study shows that there are four sub-factors; Imposed frustration, New beginning, Transition to rest, Continuing. And there was a significant difference in retirement expectation according to sex, age, income, and health status. Second, the major affecting factors on participation in pre-retirement planning programs were sex, age, job, educational attainment, and health status. Third, those who have retirement expectations of 'Imposed frustration' tend to attend re-employment, leisure, and health education. Those who have retirement expectations of 'Transition to rest' tend to attend re-employment, inauguration education. And those who have retirement of 'Continuing' tend to attend leisure education.

• Journal of the Korean housing association
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• v.25 no.1
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• pp.73-80
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• 2014

Korea is quickly transforming into an aging society. As a reaction to the accelerated aging society in recent years, there is a growing need to introduce sustainable housing policies and strategies for aging society. The main purpose of this study is to explore where people want to live after retirement. Especially, this study focuses on the residential environment such as housing types, residential location, and living environment. The main findings are as follows. First, people preferred living in a sububan-style housing in the suburban or rural areas to living in a city-style housing in the urban areas. Second, people have a strong preference for the importance of convenience in using natural environment, medical service, and cultural facilities. Third, the family life style has been changed from children-oriented life style to couple-oriented life style by showing that people like to stay with a spouse rather than with their children after retirement.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.16 no.1
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• pp.21-26
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• 2016

Canine cataract is developed with aging and can cause the blindness or surgical treatment if not treated timely. The first observation must be made by pet owners but they do not have proper equipment and knowledge to see the abnormalities. In this paper, we propose an intelligent image processing method to extract canine cataract suspicious object from non-professional equipment such as ordinary digital camera and cellular phone photographs so that even casual owners of pet dog can make a pre-diagnosis of such a surgery-needed disease as soon as possible. The experiment shows that the proposed method is successful in most cases except the dog has similar colored hair to the color of cataract.

• Journal of Acupuncture Research
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• v.27 no.2
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• pp.23-30
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• 2010

Objectives : The second derivative of photoplethysmogram waveform(SDPTG) is a simple, convenient and non-invasive technique for pulse wave analysis. This study was designed to investigate the differences in the SDPTG between the affected side and the unaffected side in hemiparetic patients after stroke, and the effects of acupuncture at Palsa(BaXie) in hemiparetic patients after stroke. Methods : To evaluate the differences between the affected side and the unaffected side in hemiparetic patients after stroke, their SDPTG were recorded by using a Cardio Peri SA6000. To evaluate the effects of acupuncture at Palsa(BaXie) in 20 hemiparetic patients after stroke and 20 healthy subjects, their SDPTG were recorded 2 times(pre-acupuncture and post-acupuncture). The SDPTG consists of an a, b, c and d wave in systole and an e wave in diastole. Sano aging index was defined as (b-c-d)/a. Results : 1. The affected side in hemiparetic patients after stroke had higher average b/a ratio(p<0.05)and Sano aging index(p<0.05) than the unaffected side 2. In a comparison of pre-acupuncture and post-acupuncture at the Palsa(BaXie), b/a ratio(p<0.05) and Sano aging index(p<0.05) was decreased significantly in both hemiparetic patients and healthy subjects. Conclusions : These findings suggest that acupuncture at Palsa(BaXie) may be effective method of reverting some of the deleterious effects on vascular function produced by stroke.

• Korean Journal of Health Education and Promotion
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• v.20 no.1
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• pp.203-218
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• 2003

In aging Korean society, many elderly people have difficulty in the areas of health, economic insecurity, role-loss(both work & spouse), loneliness, and family conflicts. Above all, retirement from work is one of the most important stressful life events having influences an elderly's persons economic & social activities, mental state, health status, and Lifelong educational programs could help the aged cope with these situations in later life. Health and social welfare are commonly recognized as an important value of life. They also have an effect on each other. Most people agree that the promotion of health and social welfare is to take a short-cut toward achieving well-being. Thus we need to develop a substantially integrated program of lifelong education, before and after retirement, for the promotion of health and welfare. Universities have the advantage of practicing lifelong educational programs because they have more material, intellectual, and human resources than any other educational facilities. As a result, the purposed of this study is to suggest life-long educational programs for promoting both health conditions and the level of social welfare by utilizing an aging center affiliated with a university. Specifically, the developmental courses of pre-retirement, learning in retirement, elder-hostels, and the connection between pre and post-retirement educational programs are proposed in this study.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.5
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• pp.660-669
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• 1998

In this paper the Hardness and Electro-chemical corrosion of the Nimonic 80A superalloy were studied. It aging heat treatments was carried out at $650^{\circ}C$, $700^{\circ}C$, $750^{\circ}C$,$800^{\circ}C$ and $850^{\circ}C$ with different time of 20min , 30min 1hour, 2hours, 4hours, and 16hours additionally 64hours and 128hours at $650^{\circ}C$. The obtained results were as follows; 1. As aging temperature increased the time for the maximum hardness was reduced from 128hours at $650^{\circ}C$ to 30min at $850^{\circ}C$ whereas the highest hardness was reduced from Hv 381 at $650^{\circ}C$ to Hv 321 at $850^{\circ}C$. 2. In the Electro-chemical corrosion test as a function of aging heat treatment time and tem-perature the corrosion potential was reversely proportional to Hardness which indicated the effects of ${\gamma}/{\gamma}'$ coherency of base material and precipitate. 3. Initiation point of the pitting was observed at grain boundary twin boundary and near${\gamma}'$ pre-cipitates. The results of composition analysis by EDS at this point indicated that sulphur originat-ed from 1N $H_2SO_4$ solution was found in depletion at the grain boundaries and the pit which arouse in the near precipitates were lack of Al Ti and Ni which are the main element of ${\gamma}'$ The depletion of such element was cause breakdown of passive film.

• Journal of the Korean Wood Science and Technology
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• v.42 no.1
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• pp.20-26
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• 2014

This paper represented the finite element analysis to estimate structural performance of stress-laminated deck, which is determined by deflection, stress, and aging characteristics of tensioning. After loading, the deflected shape showed plate behavior because pre-stressing make frictional force between each member. Compared between initial post-tension and the results, pre-stressing forces were decreased with deck deflection. This is because deflection occurred in the deck so that pre-stressing decreased due to load reduction. However, material plasticity was not considered so that advanced researches should be performed.