• Journal of the Korea Institute of Building Construction
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• v.17 no.3
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• pp.279-285
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• 2017

In this study, the development of concrete preventing initial frost damage and durability about that were evaluated by using anti-aging agent and admixture(reduced slag). As a result of experiment, initial hydration heat was increased by $C_{12}A_7$ of reduced slag components but it was not effective to development of strength. Also fluidity decreased with increasing replacement of reduced slag. This suggested that fluidity was low by rapid setting due to absent of gypsum in reduced slag components. In case of CR2G specimen that added 4% gypsum, the flow ability was higher than plain. It is considered that concrete developed using reduced slag should use $SO_3$. Result of durability experiments, the durability decreased with increasing replacement amount of reduced slag.

• Annals of Geriatric Medicine and Research
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• v.22 no.4
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• pp.167-175
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• 2018

Sarcopenia, a common clinical syndrome in older adults, is defined as decreased muscle mass, strength, and physical performance. Since sarcopenia is associated with the incidence of functional decline, falls, and even mortality in older adults, researchers and health care providers have been keen to accumulate clinical evidence to advocate the screening and prevention of sarcopenia progression in older adults. The factors that may accelerate the loss of muscle mass and function include chronic diseases, inactivity, and deficiency in appropriate nutritional support. Among these, nutritional support is considered an initial step to delay the progression of muscle wasting and improve physical performance in community-dwelling older adults. However, a nationwide study suggested that most Korean older adults do not consume sufficient dietary protein to maintain their muscle mass. Furthermore, considering age-associated anabolic resistance to dietary protein, higher protein intake should be emphasized in older adults than in younger people. To develop a dietary protein recommendation for older adults in Korea, we reviewed the relevant literature, including interventional studies from Korea. From these, we recommend that older adults consume at least 1.2 g of protein per kg of body weight per day (g/kg/day) to delay the progression of muscle wasting. The amount we recommend (1.2 g/kg/day) is 31.4% higher than the previously suggested recommended daily allowance (i.e., 0.91 g/kg/day) for the general population of Korea. Also, evidence to date suggests that the combination of exercise and nutritional support may enhance the beneficial effects of protein intake in older adults in Korea. We found that the current studies are insufficient to build population-based guidelines for older adults, and we call for further researches in Korea.

• Korean Journal of Heritage: History & Science
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• v.49 no.4
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• pp.114-125
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• 2016

Lacquer is one of the most widely used natural resin in East Asia since Neolithic Age. As a major ingredient of lacquerware, lacquer is waterproof, insect-proof and rot-proof to be durable and anti-abrasion, generally utilized for mainly painting purpose. According to lacquerware excavated from several sites of Japan and China, lacquerware seems to appear in Neolithic Age. On the other hand in case of excavation research in Korea, lacquerwares are found after the Bronze Age. The initial purpose of lacquer is estimated to be adhesive, regarding the literatures mentioning bitumen(Yeoksceong ), animal glue(Kyeo) and egg alumen(Nanbaek). Especially piece of jar coffin unearthed in Pyeongtaek Daechu-ri site had trace of restoration by lacquer and hemp as an evidence of lacquer for adhesion in Pre-Three Kingdoms period. Since then a trend to restore the broken ceramics with lacquer and decorate with golden foil lasted especially in Joseon Dynasty. In the field of gold plated lacquer method, mother-of-pearl inlaying technique for lacquerware and restoration of buildings, lacquer is still used as adhesive. Due to matter of reversibility lacquer is being avoided for conservation and restoration of cultural heritage. Lacquer as a traditional material for adhesive since ancient times, however, has advantage in adhesion strength and durability. Because synthetic resin adhesive has problem of emission of volatile organic compounds and aging over time, lacquer receives attention recently. On the contrary, by combination adhesive from mixing lacquer and animal glue, already proved the possibility of applicability and chemical modification. A research to utilize lacquer as modern paint or functional material is also conducted continuously also in China and Japan. To put traditional material into practical use and modernize, chemical research from the molecular level of the lacquer is necessary in the near future.

• The Journal of Engineering Geology
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• v.31 no.3
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• pp.381-393
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• 2021

Physical, mechanical, hydraulic, and geophysical tests were applied to validate methods of inspecting the effectiveness of grouting on an agricultural reservoir dam. Data obtained from series of in situ and laboratory tests considered four stages: before grouting; during grouting; immediately after grouting; and after aging the grouting for 28 days. The results of SPT and triaxial tests, including the unit weight, compressive strength, friction angle, cohesion, and N-value, indicated the extent of ground improvement with respect to grout injection. However, they sometimes contained errors caused by ground heterogeneity. Hydraulic conductivity obtained from in situ variable head permeability testing is most suitable for identifying the effectiveness of grouting because the impermeability of the ground increased immediately after grouting. Electric resistivity surveying is useful for finding a saturated zone and a seepage pathway, and multichannel analysis of surface waves (MASW) is suitable for analyzing the effectiveness of grouting, as elastic velocity increases distinctly after grouting injection. MASW also allows calculation from the P- and S- wave velocities of dynamic properties (e.g., dynamic elastic modulus and dynamic Poisson's ratio), which can be used in the seismic design of dam structures.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.5
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• pp.607-616
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• 2022

Corrosion and degradation of reinforced structures due to abnormal climates and natural disasters further accelerate the aging of structures. Coping with the decrease in structure performance, many old structures are being repaired and reinforced with low-weight and high-strength materials such as glass fiber composite material (GFRP). To further contribute, this paper focus on a more economical and eco-friendly material, basalt fiber composite (BFRP), which provide a more effective lateral constraint effect for seismic reinforcement. The main variables considered in this study are the curing temperature during the manufacturing of BFRP and the material characteristics of the target concrete member. The lateral constraint reinforcement effect was investigated through the evaluation of the performance of normal concrete and those with improved durability through fiber reinforcement. The reinforcement effect was 3.15 times for normal concrete and 3.72 times for fiber reinforced concrete, and the difference in reinforcement effect due to the improvement of the durability characteristics of the compression member was not significant. Lastly, the performance of the BFRP was compared with the results of the GFRP reinforcement from the previous study. The effect of the BFRP reinforcement was 1.18 times better than that of the GFRP reinforcement.

• Journal of Family Resource Management and Policy Review
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• v.27 no.1
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• pp.1-12
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• 2023

This study forecasts the outlook 10 years from now regarding domestic labor and caregiving by the Baby Boomer generation and the preparations needed in the context of the Fourth Industrial Revolution. The scenario-planning method was used to explore changing trends in domestic labor and caregiving, the rationale for which has been questioned by both seniors and family welfare experts. Based on the results of the survey and our researchers' opinions, it was concluded that the changing trends were caused by two factors: the probability of alterations in domestic labor and the strength of family relationships. On the basis of these conclusions, four scenarios regarding baby boomers' domestic labor and caregiving in 10 years were proposed using two axes: the "high and low probability of alterations" and the "strengthening and weakening of family relationships." The first scenario is a "preference for the self-caring form of family," which has a high probability of domestic labor alterations and weak family relationships. The second scenario is a "preference for the flexible form of family," which has a high probability of domestic labor alterations and strong family relationships. The third scenario is a "preference for the traditional form of family," which has a low probability of domestic labor alterations and strong family relationships. The fourth scenario is a "preference for the public caregiving form of family," which has a low probability of domestic labor alterations and weak family relationships. These results provide basic information about the various aspects of baby boomers' lives-including the development of various goods and services, the establishment of policies regarding seniors, and programs for successful aging-and can help equip our society to take the actions needed for a super-aged population.

• 한국노년학
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• v.27 no.2
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• pp.371-392
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• 2007

Marital status has drawn much attention as previous studies have been pointed it out as a key factor of health. Nonetheless, systematic studies on elderly marital status and health have been quite limited, for most researches have neglected the varying effects of marital status on health over the lifespan and mainly focused on midlife. This study, using nationwide survey on elderly population, attempts to discover the health differentials between widowed and married elderly and explain the differences though the structure and function of their social network. The results reveal that the magnitudes of marital status effects were differed by dimensions of health. The widowed were more likely to be unhappy than married, even after controlling the socio-demographic characteristics. In physical health, however, the health differences between widowed and married were less noticeable or disappeared, as sex, age and other structure factors were considered. Furthermore, the strength of social network factors affecting the physical and mental health of elderly turned out to be different between married and widowed: widowed were more likely than married to be affected by the contact with children and less likely to be affected by contact with friends/relatives. Such results had both positive and negative impact on physical and mental health of widowed. This may imply the difference in pathways of regulating health among the married and widowed elderly.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.3
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• pp.161-168
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• 2023

Converter slag is a by-product generated by refining the pig iron produced into molten steel in the blast furnace, occupying about 15 % of the weight of steel production. It has a high free-CaO content that can generate expansion cracks when used for concrete aggregate. This is the main reason to make it difficult to recycle. To solve this problem, government guideline requires that converter slag has to be aged in an open yard for 90 days. However, aging can not be perfectly performed because it entails time and cost. In this study, we tried to investigate the applicability of converter slag as a cementitious material rather than an aggregate by mixing converter slag with mortar formulations. According to the EDS results of the converter slag in the experiment, we found that screening in the aggregate phase was more effective than that in the powder phase. When the particles separated by a magnet in the aggregate state were pulverized and used for concrete up to a 15 % replacement ratio, various engineering characteristics, such as flow, length change, and compressive strength, showed engineering characteristics similar to those of the control mix.

• Korean Journal of Community Nutrition
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• v.28 no.6
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• pp.480-494
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• 2023

Objectives: This study sought to assess the effectiveness of community-based nutrition counseling on improving nutritional status, managing complex chronic diseases, and enhancing the quality of life for elderly individuals with chronic conditions, particularly in older adults with high levels of food insecurity and multiple chronic illnesses. Methods: Thirty elderly subjects with diabetes and hypertension who were registered at local Senior Welfare Center received individualized nutrition counseling, based on their Nutrition Quotient for the Elderly (NQ-E) index. Over a 16-week period, they received tailored counseling and underwent various health and nutritional assessments. The final analysis included 28 participants after two dropped out. Data analysis was conducted using the SPSS v28.0. Results: The subjects were over 70, with multiple chronic diseases including diabetes and hypertension and predominantly female. After 16 weeks, significant improvements were observed in the subjects' grip strength, and HbA1c levels, as well as in their NQ-E scores, indicating improved dietary balance and diversity. There were no significant improvements in the 'Moderation' subdomain of the NQ-E index, suggesting that this aspect requires further attention in nutritional counseling. The subjects' nutritional risk scores (NSI) were also significantly decreased, indicating less nutritional risk. Lastly, as measured by the SF-36K, the subjects' quality of life showed significant improvement in several domains including physical role performance and social function. Conclusions: This study demonstrates that tailored nutrition counseling, based on the NQ-E index, can improve elderly health, manage chronic diseases, and enhance quality of life. This approach potentially broadens the scope of community nutritionists' roles within an aging society. However, additional research is necessary to evaluate these interventions' long-term effects and sustainability.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.172-178
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• 2021

In the ship repair market, interest in maintenance and repair is steadily increasing due to the reinforcement of prevention of environmental pollution caused by ships and the reinforcement of safety standards for ship structures. By reflecting this effect, the number of requests for repairs by foreign shipping companies increases to repair shipbuilders in the Southwest Sea. However, because most of the repair shipbuilders in the southwestern area are small and medium-sized companies, it is difficult to lead to the integrated synergy effect of the repair shipbuilding companies. Moreover, the infrastructure is not integrated; hence, using the infrastructure jointly is a challenge, which acts as an obstacle to the activation of the repair shipbuilding industry. Floating docks are indispensable to operating the repair shipbuilding business; in addition, most of them are operated through renovation/repair after importing aging caisson docks from overseas. However, their service life is more than 30 years; additionally, there is no structure inspection standard. Therefore, it is vulnerable to the safety field. In this study, the finite element analysis program of ANSYS was used to evaluate the structural safety of the modified caisson dock and obtain additional structural reinforcement schemes to solve the derived problems. For the floating docks, there are classification regulations; however, concerning structural strength, the regulations are insufficient, and the applicability is inferior. These insufficient evaluation areas were supplemented through a detailed structural FE-analysis. The reinforcement plan was decided by reinforcing the pontoon deck and reinforcement of the side tank, considering the characteristics of the repair shipyard condition. The final plan was selected to reinforce the side wing tank through the structural analysis of the decision; in addition, the actual structure was fabricated to reflect the reinforcement plan. Our results can be used as reference data for improving the structural strength of similar facilities; we believe that the optimal solution can be found quickly if this method is used during renovation/repair.