• Korean Journal of Food Science and Technology
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• v.54 no.3
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• pp.251-256
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• 2022

This study was conducted to determine whether Diospyros lotus L. fruit could be used as a natural functional food ingredient and whether its use should be increased. D. lotus fruit powder was found to have high acidity in the immature IDL stage and significantly higher sugar content in the mature MDL stage. The levels of crude fat, selenium, and tannins decreased significantly from the IDL stage to the MDL stage in D. lotus fruit powder. However, the levels of magnesium and calcium were significantly greater in the MDL stage than in the IDL stage (p<0.05). The total phenol content was significantly higher in the IDL stage, but the DPPH radical scavenging activity significantly increased in the MDL stage (p<0.05). In conclusion, the fruits of D. lotus. have high nutritional quality in both the immature and mature growth stages. Thus, it is a good candidate for use as a functional food, and its use should be increased because of its high nutritional qualities.

• Journal of Industrial Convergence
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• v.20 no.1
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• pp.63-68
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• 2022

In schools and corporate buildings, public WiFi Access Points are installed on the ceilings of hallways. In the case of an architectural structure in which a WiFi signal enters through a steel door made of a material with high signal attenuation, Internet connection is frequently cut off or fails when the door is closed. To solve this problem, our research implements an economical and portable WiFi extender using a Raspberry Pi and an auxiliary battery. Commercially available WiFi extenders have limitations in the location where the power plug is located, and WiFi extension using the WiFi hotspot function of an Android smartphone is possible only in some high-end models. However, because the proposed device can be installed at the position where the Wi-Fi reception signal is the best inside the door, the WiFi range can be extended while minimizing the possibility of damage to the original signal. Experimental results show that it is possible to eliminate the shadows of radio waves and to provide Internet services in the office when the door is closed, to the extent that web browsing and real-time video streaming for 720p are possible.

• Applied Chemistry for Engineering
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• v.33 no.4
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• pp.343-351
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• 2022

Lithium-ion batteries (LIBs) are considered promising energy storage devices with good performance such as high energy density, slow self-discharge rate, high rate charge capacity, and long battery life. However, the application of these LIBs in the high-energy density electric vehicle and large device industries poses a major safety problem. In order to solve this problem, developing a material having high thermal stability and intrinsic safety is the ultimate solution for improving the stability and electrochemical performance of LIBs. This review introduced a surface modification technology of a separator to overcome the stability problem of a commercial separator, and summarized and summarized the research trends using the modified separator for a lithium-ion battery. Based on this, the future prospects for the separator development by surface modification were discussed.

• Journal of Digital Convergence
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• v.20 no.5
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• pp.643-651
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• 2022

This study was conducted to examine the oral health, dental treatment and insurance awareness of the community during the COVID-19 period from September 1 to October 29, 2021 for patients who visited a local dental clinic in Gangwon-do. For analysis, SPSS Statistics 24.0 program was used. As a result of the analysis, it was found that oral health status, interest in oral health, and awareness of health insurance expansion affect dental treatment during the COVID-19 period. In addition, those who did not receive oral health education, those with a high school diploma or lower, and those with poor oral health showed positive results for dental treatment during the COVID-19. In conclusion, it is necessary to expand publicity on oral health education, and to list the cost of infection control in health insurance and separate compensation materials. In future research, I think that it is necessary to conduct research through a variety of subjects and study the expansion of insurance in detail.

• Analytical Science and Technology
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• v.21 no.5
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• pp.432-437
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• 2008

In this study, polysilanes were synthesized by electroreduction with different monomers such as $CH_3HSiCl_2$, $PhSiCl_3$, $CH_3SiCl_3$ and $(CH_3)_2SiCl_2$ by Mg electrodes under ultrasonic radiation. The effects of monomers and additives (p-dibromobenzene (DBB), naphthalene (NAPH) and anthracene (ANTH)) on the reaction rate were investigated. Polymerization of $PhSiCl_3$ among the four monomers showed the highest rate. p-dibromobenzene (DBB) was proved the most effective additive. Based on the observations, some possible reaction mechanisms of the polymerization were proposed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6C
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• pp.231-239
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• 2010

This paper presents the thermal conduction analysis (using ABAQUS ver 6.10 and FLUENT ver 6.3.26) of geothermal energy for PHC, steel and copper energy piles by considering subsurface environment, thermal efficiency of grouting materials, and fluid velocity of circulating fluid. Results show that higher thermal efficiency for copper pile is observed followed by steel and PHC piles depending on the grouting materials and subsurface condition. The fluid velocity of 0.6m/s presents most efficient outflow temperature (275.4K) and heat exchange rate (103.1W/m) for the case of PHC pile during 8 hours operation. Analysis of operation schedule concludes that 16 hours of stand-by allows charging geothermal energy following 8 hours operation in winter season is most appropriate with 0.1K of temperature difference from the steady-state condition.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.32-32
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• 2023

본 연구는 16세기 과거에서 낙방한 시권(試紙)인 낙폭지(落幅紙)가 어떻게 재활용되었는지에 대해 고 찰하는 것이 목적이다. 과거 시험 답안지는 시권, 시지(試紙), 명지(名紙), 과지(科紙)라 하였으며 두껍고 품질 좋은 종이가 사용되었다. 국가의 특별한 경사가 있거나 왕이 친림한 과거 시험의 경우 응시자에게 국가에서 시지를 제공하였으나, 그 외 3년마다 치르는 정기시험인 식년시(式年試)는 개인이 별도로 마련하였다. 전국 각 도와 한성부에서 치러졌던 초시(初試)를 비롯한 복시(覆試), 별시(別試), 증광시(增廣試), 춘당대시(春塘臺試) 등 과거 응시자의 수는 조선 후기로 갈수록 증가하였다. 이 때문에 시지 마련은 응시자 개인뿐 아니라 국가의 부담으로 작용하게 되었다. 조선시대 과거에 합격한 시지는 응시자에게 돌려주었으나 불합격한 시지의 경우는 돌려주지 않고 국가에서 재활용하였다. 낙폭지는 북방 군사들의 추위를 막는 방한용 의복인 지의(紙衣)로 사용되었으며, 화전(火箭), 가슴을 가리는 갑옷인 엄심갑(掩心甲), 비를 막는 장막용이나 우의(雨衣)로 사용되었다. 낙폭지는 건물 내부 도배 재료로 초배(初褙)에 이용되었으며, 그림이나 책의 배접용으로 활용되었다. 16세기 『묵재일기』에는 이문건이 32년간 성주 지방에서 유배 생활을 하며 인근 지역 관인(官人)과 지인들을 통해 주기적으로 낙폭지를 입수했던 기록을 살필 수 있다. 지방의 종이 제작 정도, 종이 수급 현황, 낙폭지 재활용에 대한 구체적인 양상을 통해 일상 속 종이 재활용 상황을 파악하는 단서를 제공하였다.

• Journal of the Korean GEO-environmental Society
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• v.25 no.5
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• pp.21-27
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• 2024

Limestone-based cement has been well utilized as a construction material throughout the world, but as civil and architectural development accelerates, limestone will gradually be depleted. The use of cement, the main material for civil engineering and construction, is rapidly increasing in modern times, and the depletion of high-quality limestone resources will be greater than expected in the future. Therefore, if existing resources can be used as construction materials to replace cement based on accumulated technology, the depleting limestone resources can be utilized for a longer period of time. In order to determine whether Hwang-toh, which forms about 10% of the surface layer of Korea's terrain, can be partially utilized as a construction material, this study aims to develop a Hwang-toh accelerator agent and prove whether it can be applied to the field through indoor tests.

• Journal of the Society of Disaster Information
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• v.20 no.2
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• pp.419-429
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• 2024

Purpose: To enhance the non-combustibility of fire protection piping insulation and improve the heat resistance of smoke extraction duct insulation, I plan to verify the suitability of AES insulation materials for these applications through performance testing. Method: The non-combustibility, heat resistance, and thermal insulation performance of AES insulation materials will be verified through various tests. Result: According to the 'Standards for Flame Retardancy and Fire Spread Prevention of Building Finishing Materials,' the results of non-combustibility and gas toxicity tests confirmed the non-combustible properties. The standard fire resistance tests verified the fire resistance performance. Additionally, the thermal insulation performance was confirmed through building insulation tests. Conclusion: As the performance tests on AES inorganic insulation materials have proven their noncombustibility, fire resistance, and thermal insulation performance, these materials are considered a viable alternative for improving fire spread prevention in buildings.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.8 no.2
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• pp.75-82
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• 2013

This study was carried out to contribute to the self-help and sustainability of grassroots business in Gangwon-do. To achieve this, after setting up the concept of community business, understanding the current designating status of community business and analyzing the business content and the business promotion system, I tried to analyze the continuing factors of businesses and shops, which are more than hundred years old, in Japan and seek a solution to the sustainability of community business in the province. The community business in the province, which is designated and operated, is like this; 86 preliminary social businesses, 62 town businesses, 38 social businesses. The total comes to 186. The preliminary social businesses and the social businesses are assigned more in urban area and the manufacturing sector and educational field have a lot of business contents. When it comes to the business promotion system, there are many incorporated companies and limited companies. While the town businesses are assigned more in county area, the agricultural food field and cultural world have a lot of business contents. When it comes to the main participant of business, the agricultural corporations took the first place overwhelmingly. Especially, I found out that the main participants of community business consist of 38 voluntary associations, which is 20.4 %, and we need to make up for the specialty deficiency in business management. In order to keep the continuity of community business in the province, we could achieve the results of manpower development through the case analysis research, securing good materials which can give the consumers confidence, increasing the quality of the products, maintaining high technical skills, keeping up the tradition of business and demanding forecasting. I think a successive research efforts will be required for securing good materials and increasing the quality of the products in tandem with the local community. And also we need to establish a supporting & operating system through the liaison between the business & academic world, business & administration, and business & business for securing a management specialty as an industrialist.