• Journal of the Korea Institute of Building Construction
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• v.3 no.3
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• pp.107-112
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• 2003

This study is to investigate the properties of concrete with crushed sand on site and to propose a quality guideline for its use as artificial sand and concrete. From our experimental result in laboratory and site, we found that demand water of concrete with crushed sand for target slump increased by 18kg/m3 compared to mixed sand and l8kg/m3 compared to sea sand respectively. The compressive strength increased by around 3∼6% when compared to concrete with sea sand. Accordingly, our study showed that the combined sand mixed with sea sand would be desirable to obtain workability and strength of concrete including dry shrinkage and bleeding test. Furthermore, the optimal replacement percentage of crushed sand was 50% with sea sand. As such, crushed sand would be sufficient as fine aggregate for concrete in terms of economic efficiency and quality. Crushed sand, on the other hand can only be used as fine aggregate when VFS(Very Fine Sand) is below 3.5 percentage of weight of sand and particle shape is above 55 percentage. Also, the particle shape and microsand passing NO.200 sieve should continually be improved to increase workability of concrete on site.

• The Transactions of the Korea Information Processing Society
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• v.6 no.5
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• pp.1189-1202
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• 1999

As compared with VOD data, NOD article data has the following characteristics: it is created at any time, has a short life cycle, is selected as not one article but several articles by a user, and has high access locality in time. Because of these intrinsic features, user access patterns of NOD article data are different from those of VOD. Thus, building NOD system using the existing techniques of VOD system leads to poor performance. In this paper, we analysis the log file of a currently running electronic newspaper, show that the popularity distribution of NOD articles is different from Zipf distribution of VOD data, and suggest a new popularity model of NOD article data MS-Zipf(Multi-Selection Zipf) distribution and its approximate solution. Also we present a life cycle model of NOD article data, which shows changes of popularity over time. Using this life cycle model, we develop LLBF (Largest Life-cycle Based Frequency) prefetching algorithm and analysis he performance by simulation. The developed LLBF algorithm supports the similar level in hit-ratio to the other prefetching algorithms such as LRU(Least Recently Used) etc, while decreasing the number of data replacement in article prefetching and reducing the overhead of the prefetching in system performance. Using the accurate user access patterns of NOD article data, we could analysis correctly the performance of NOD server system and develop the efficient policies in the implementation of NOD server system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.429-432
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• 2004

The demand for electric power keeps growing, and tends to be more effective. Polymer insulators have been manufactured for almost twenty years and the excellent insulation performance of polymer insulators is attractive. Polymeric materials are now widely used as a replacement for inorganic materials such as porcelain or glass for the outdoor insulation of high voltage insulation. GFRP has been used widely as a core materials for polymer insulators. This paper reports the mechanical properties of GFRP for insulators. The bending strength was simulated and evaluated according to the winding angle. The fiber orientation in GFRP has a great effect on the strength of GFRP because the strength of GFRP mainly depends on the strength of fiber. Results of simulated and evaluated strength of GFRP were compared each other. The simulated strength of GFRP rod was different from the evaluated strength. It was caused that the shear stress had a great effect on the strength of GFRP although the stress of parallel direction of GFRP was much higher.

• Journal of the Korean Society of Food Culture
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• v.36 no.4
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• pp.373-381
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• 2021

The number of vegans has increased rapidly due to religious and ethical beliefs, environmental concerns, health, etc. Also, as interest in healthy and safe food increases, the demand for organic products or nutrition-enhanced products is increasing. Therefore, this study aimed to investigate the selection attributes and purchasing behavior for protein-fortified and vegan snacks. It is anticipated that the results would find use as basic data for developing protein-fortified snacks for vegans that can meet consumer needs and derive marketing strategies. A survey was conducted on 140 consumers. According to the analysis of their purchase behavior, the number of people who had purchased high-protein snacks and vegan snacks was higher than those who did not have prior experience. The reasons for the purchase of protein fortified snacks included 'meal replacement' at 'offline-convenient store/supermarket'. Vegan snacks were purchased for 'ethical beliefs, health, environment' at 'offline-vegan restaurant, bakery'. Both snacks showed above-normal preferences. However, it is necessary to improve taste and flavor when developing these products as these were the factors that negatively impacted the preferences. The attributes were factorized into the 'showing off factor', 'sensory factor', 'credence factor', and 'functional factor' and the 'sensory factor' was considered the most important.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.30-40
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• 2007

The demand for light-rail construction projects has recently been increasing, and they are mostly supervised by private construction companies. Therefore, a private construction company that aim to raise gains from the operation of the facilities during the contract period greater than what they invested should b able to accurately calculate the costs from the aspect of Life Cycle Cost (LCC). In particular, a light-rail transit bridge that has a heavier portion from the aspect of the cost of light-rail transit construction requires a more accurate calculation method than the conventional LCC calculation method. For this, an LCC analysis model was developed and a cost breakdown structure was suggested based on literature review. The construction costs by shape of the upper part of a light-rail transit were calculated based on the cost breakdown system presented in this paper, and the cost generation cycle and cost unit price were collected and analyzed based on records on maintenance costs, rehabilitation and replacement. In addition, after forming some hypotheses in order to perform the LCC analysis, economic evaluation was conducted from the aspect of the LCC by using performance data by item.

• Journal of Medicine and Life Science
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• v.20 no.1
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• pp.32-37
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• 2023

The demand for total knee arthroplasty (TKA) is rapidly increasing worldwide. The most common indication for TKA is osteoarthritis (OA); however, some patients with rheumatoid arthritis (RA) also undergo TKA. This study aimed to investigate the effects of RA on TKA. Our findings revealed that patients with RA underwent TKA at a younger age than did patients with OA. However, contrary to the findings of pre-21st century studies, the average age of TKA among patients with RA was not significantly different from that of patients with OA. Additionally, patients with RA had a 1.5-fold higher risk of undergoing TKA. Although not statistically significant, patients with RA had a higher revision TKA rate, a shorter time until revision TKA, and underwent more revision TKAs due to infections than did patients with OA. An analysis of factors that affect revision TKA revealed that the risk of revision increased if the erythrocyte sedimentation rate and C-reactive protein levels were increased at the time of TKA. This study showed that patients with RA have a slightly higher risk of undergoing TKA than did patients with OA. Furthermore, the presence of inflammation at the time of TKA increases the risk of revision; therefore, inflammation should be adequately controlled before performing TKA.

• The Journal of Economics, Marketing and Management
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• v.6 no.4
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• pp.41-49
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• 2018

Purpose - The purpose of the study was to investigate restaurants increasing seaweed of marine products and to let consumers live healthy and happy lives and to discuss increase of seaweeds consumption. The purpose of the study was to give consumers good food and to live healthy and happy life and to elevate life quality and to produce added value by increase of consumption of seaweeds such as laver, brown seaweed, tangle and gracilaria and others and to give economic advantage. The seaweed could be produced in large quantity without spending of much money in accordance with demand to make use of it at restaurants. Research design, data, and Methodology - The author visited restaurant businessmen at Suwon, Anyang, Hwaseong and Yongin to investigate low sales by in-depth interview. The study investigated Kodari-jorim restaurants that made use of laver ssam for side dish. The subject was HS distributors to let restaurant keepers think of seaweeds and replacement of vegetable by seaweed. Results - Women customers who thought of health and diet usually selected menu at the restaurants not to appeal. Conclusions - Menu with high quality seaweeds (low calory, satiety and health) can satisfy women customers thinking much of health and diet to increase consumption of seaweeds. The study was exploratory to investigate in qualitative and quantitative way in the future.

• The Korean Journal of Food & Health Convergence
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• v.9 no.5
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• pp.1-5
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• 2023

As the elderly population is rapidly increasing not only domestically but also globally, convenience foods for the elderly population are receiving attention. Therefore, the senior food market continues to grow rapidly both domestically and overseas. In relation to this, this study seeks to explore convenience food preferences through the growth status of the convenience food market and the demand for convenience food among the elderly population. We would like to consider various factors that influence the increase in convenience food consumption among the elderly population. This study uses meta-analysis and systematic literature research to find ways to revitalize the convenience food market targeting the elderly population. As a result of the analysis, it was mentioned that in order to revitalize the convenience food market for the elderly population, it is important to develop products with high nutritional value, suitable for the physical characteristics of the elderly population, and low price, and to consider convenience and accessibility. Through a multifaceted approach, we aim to increase the need for convenient food products that meet the needs of the elderly population, contribute to improving the health and well-being of the elderly, and further efficiently manage the health of the elderly nationally and globally.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.5
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• pp.388-396
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• 2023

As the government encourages the replacement of small FRP ships with eco-friendly aluminum ships due to environmental pollution problems, interest and demand for small aluminum ships are increasing. It is known that the vibration and noise of aluminum ships are somewhat vulnerable than that of FRP ships. However, in the process of designing and manufacturing small aluminum fishing boats, vibration and noise are not reviewed. In this study, vibration analysis is performed on three existing aluminum fishing boats, and the vibration characteristics of small aluminum boats are identified. Through this study, we intend to contribute to improving the vibration quality of small aluminum ships.

• Korea Trade Review
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• v.46 no.2
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• pp.121-140
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• 2021

The ship recycling or scrap is a phenomenon in the process of vessels life cycle has ended in the shipping industry. Scrap are greatly affected by freight rates due to ship demands. Not only that, environmental regulation and economic scale vessel demand are processes that must exist in the shipping industry as they obtain management for existing vessels. In the past, shipbreaking yard had tried to work without protection for poverty, without poor working conditions and facilities to prevent the emission of harmful substances. However, the issue of environmental pollution has been raised the Basel and Hong Kong Convention have been adopted, and a new replacement of the ship scrap that induces serious pollution is required. In this study, 165 countries were analyzed to confirm the importance of determining the ship solution. As a result of the analysis, it was found that the Environmental Performance Index, which is a measure of environmental regulation, is the most influential factor of ship scrapped volume. The determinant of whether lower labor cost can be secured is more correlated with population than GDP per capita. The implications of the results of the regression analysis mean that if environmental regulations for ship scrap of the future are strengthened, the status of Bangladesh and Pakistan, which currently account for half of the world's ship recycling, may change.