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Evaluation on the Performance of Coating Materials for Improving the Durability of Concretes (콘크리트의 내구성 증진을 위한 코팅재의 성능 평가)

  • Kim, Sung-Soo;Choi, Choon-Sik;Nam, Yong-Hyuk
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.7 no.4
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    • pp.99-107
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    • 2003
  • Normally coating is used a method for protecting reinforced concrete. For this purpose, organic as well as inorganic coatings are used. The advantages of inorganic coatings are lower absorption of UV, non-burning etc. On the other hand, organic coatings have the advantage of low permeability of $CO_2$, $SO_2$ and water. Organic coatings provide better protection for reinforced concrete. However, in organic coatings such as epoxy, urethane and acryl, long-term adhesive strength is reduced and the formed membrane of those is blistered by various causes. Also when organic coatings are applied to the wet surface of concrete, they have a problem with adhesion. So, we developed coating material, WGS-Eco which was hybridized with polymer and cement based material to protect concrete structures and solve problems of organic coatings. This study was conducted an comparative evaluation on physical and durable performance of developed coating material and previously used coating materials. As a result, the performance of developed coating material was not inferior to organic coating materials. So, the developed coating material was considered as a suitable coating material which had advantages of inorganic and organic coatings for protecting concrete.

Designing optimized food intake patterns for Korean adults using linear programming (I): analysis of data from the 2010~2014 Korea National Health and Nutrition Examination Survey (선형계획법을 이용한 한국 성인의 최적 식품섭취패턴 설계 (I) : 2010~ 2014년 국민건강영양조사 자료 분석)

  • Asano, Kana;Yang, Hongsuk;Lee, Youngmi;Yoon, Jihyun
    • Journal of Nutrition and Health
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    • v.51 no.1
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    • pp.73-86
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    • 2018
  • Purpose: The aim of this study was to design optimized food intake patterns that meet the nutritional recommendations with minimal changes from the current food intake patterns among Korean adults using linear programming. Methods: Data of a one day 24-hour dietary recall from the 2010 ~ 2014 Korea National Health and Nutrition Survey were used to quantify the food items that Korean adults usually consumed. These food items were categorized into seven groups and 24 subgroups. The mean intakes and intake distributions of the food groups and the food subgroups were calculated for eight age (19 ~ 29, 30 ~ 49, 50 ~ 64, and over 65 years old) and gender (male and female) groups. A linear programming model was constructed to minimize the difference between the optimized and mean intakes of the food subgroups while meeting the Dietary Reference Intakes for Koreans (KDRIs) for energy and 13 nutrients, and not exceeding the typical quantities of each food subgroup consumed by the respective age and gender groups. Results: The optimized food intake patterns, which were a set of quantities of 24 food subgroups, were obtained mathematically for eight age and gender groups. Overall, major modifications of current diet were required to increase the intake of vegetables and milk/dairy products and decrease the Kimchi intake. The optimized intake of seasonings, including salt, was calculated to be 0 g for all the age and gender groups. Conclusion: The optimized food intake patterns designed using linear programming in this study lack feasibility because they suggest a seasoning consumption of 0 g. Modification of intake goal for sodium is needed to obtain optimized food intake patterns with improved feasibility.

An effect of the shape of cutting blade on cutting resistance of rice stalk (콤바인 예취날의 형상이 볏짚절단저항에 미치는 영향)

  • Choi, Woo-Young;Kim, Tae-Han
    • Current Research on Agriculture and Life Sciences
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    • v.22
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    • pp.41-48
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    • 2004
  • This study is performed in order to provide the basic information needed for the development of cutting blade for combine. By comparing the developed cutting blade of which were made groove of the surface with the common cutting blade. Friction force and cutting resistance by the cutter bar speed ratio and moisture content of rice stalk were shown as follows: 1. The friction force of the developed cutting blade is shown at the average value $0.12kg{\cdot}m$ as 25% lower than one of the common blade at the average value $0.16kg{\cdot}m$. 2. The cutting resistance of the developed cutting blade is shown as respectively 12%, 15% and 20% lower than one of the common blade at the moisture content of rice stalk of 14.2%, 55.3% and 84.2%. 3. The cutting resistance of cutting blade by two different driving types is shown that the one by double driving type is $0.2kg{\cdot}m$, and the one by single driving type is $0.24kg{\cdot}m$. 4. Optimum cutter bar speed ratio of cutting blade is shown as different according to the moisture content of rice stalk.

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Study of Selective Cell Drop Scheme using Fuzzy Logic on TCP/IP (TCP/IP에서 퍼지 논리를 사용한 선택적 셀 제거 방식에 관한 연구)

  • 조미령;양성현;이상훈;강준길
    • Journal of the Korea Computer Industry Society
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    • v.3 no.1
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    • pp.95-104
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    • 2002
  • This paper presents some studies on the Internet TCP/IP(Transmission Control Protocol-Internet Protocol) traffic over ATM(Asynchronous Transfer Mode) UBR(Unspecified Bit Rate) and ABR(Available Bit Rate) classes of service. Fuzzy logic prediction has been used to improve the efficiency and fairness of traffic throughput. For TCP/IP over UBR, a novel fuzzy logic based cell dropping scheme is presented. This is referred to as fuzzy logic selective cell drop (FSCD). A key feature of the scheme is its ability to accept or drop a new incoming packet dynamically based on the predicted future buffer condition in the switch. This is achieved by using fuzzy logic prediction for the production of a drop factor. Packet dropping decision is then based on this drop factor and a predefined threshold value. Simulation results show that the proposed scheme significantly improves TCP/IP efficiency and fairness. To study TCP/IP over ABR, we applied the fuzzy logic ABR service buffer management scheme from our previous work to both approximate and exact fair rate computation ER(Explicit cell Rate) switch algorithms. We then compared the performance of the fuzzy logic control with conventional schemes. Simulation results show that on zero TCP packet loss, the fuzzy logic control scheme achieves maximum efficiency and perfect fairness with a smaller buffer size. When mixed with VBR traffic, the fuzzy logic control scheme achieves higher efficiency with lower cell loss.

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Separation and Purification of Antioxidant Activity Acidic Polysaccharide from Red Ginseng Marc (홍삼박으로부터 항산화 활성 산성다당체 분리 정제 및 구조 분석)

  • Ha, Yoo Jin;Kim, Seul Ki;Yoo, Seong Eui;Yoo, Sun Kyun
    • Journal of the Korean Applied Science and Technology
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    • v.34 no.4
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    • pp.915-923
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    • 2017
  • The by-products of red ginseng marc showing the improvement of health has been strongly studied because of the expectation of possibility to be used as the functional foods. This research was to investigate the extraction, separation, isolation, and evaluation of crude acidic polysaccharides related to antioxidant activity, sequently chemical structure of those products was evaluated by FT-IR and NMR. Compared with other solvents such as ethanol, methanol, propanol, acetone, and butanol, ethanol was selected. The concentration of red ginseng solution for extraction was selected as 10%(w/v) related to extraction yield(11.95%) and amount(11.8 mg/ml). In the ion exchange chromatography, aidic polysaccharides showing the highest antioxidant activity was obtained when eluted by distilled water. As results of structural analysis by FT-IR and NMR, peaks corresponding to C-O, C-O-O-, C-H, anomeric C-6, and repeated C-1 and C-6 linkages was to be presumed to be ($1{\rightarrow}6$) glycosidic linkage with the typical acidic polysaccharide.

Flavonoid Content and Antioxidant Activities of Gardenia jasminoides Ellis Seed Extracts Produced by Ethyl Acetate, Distilled Water and Methanol (치자(Gardenia jasminoides Ellis) 씨 에틸 아세테이트, 물 및 메탄올 추출물의 플라보노이드 함량 및 항산화 활성)

  • Jin, Dong-Hyeok;Oh, Da-Young;Kang, Dong-Soo;Lee, Young-Geun;Kim, Han-Soo
    • Journal of the Korean Applied Science and Technology
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    • v.34 no.4
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    • pp.1094-1103
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    • 2017
  • The purpose of this study was to measure the bioactivity and antioxidant activity of seed from Gardenia jasminoides Ellis fructus (GJE). We determined tannin content ($1.517{\pm}0.003mg\;CE/g$, mg of catechin equivalents). The extraction yields of the GJE seed solvent were distilled water (DW) 36.61%, 70% methanol 30.10% and ethyl acetate (EA) 20.40%. The antioxidant activities of the extracts were significantly increased (0.2, 0.4, 0.6 mg/mL). Flavonoid contents (mg QE/g, mg of quercetin equivalents) were observed in the order of 70% methanol (0.799), DW (0.565) and EA (0.117). Antioxidant activities (DPPH, OH, ferrous ion-chelating capacity) were similar to the flavonoid content of each solvent. But ABTS scavenging activity and SOD like ability of DW extract were higher than 70% methanol extract. Comparing the yield and the antioxidant activity of each solvent of GJE seed, it seems to be preferable to use DW and 70% methanol solvent for extraction. As a result of this experiment, it has high antioxidant activity and physiological activity, which is expected to be highly valuable as a functional food and a natural antioxidant.

Synthesis of ITiO(Indium Titanium Oxide) particle by sol-gel and investigation on light transmittance of deposited ITiO thin film (졸-겔법에 의한 ITiO(Indium Titanium Oxide) 입자의 합성과 ITiO 박막의 광투과도 조사)

  • Go, Eun Ju;Kim, Sang Hern
    • Journal of the Korean Applied Science and Technology
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    • v.34 no.4
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    • pp.705-716
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    • 2017
  • In this study, Indium-Titanium hydroxide particle with 0.5, 1.0, 1.5 wt% of $TiO_2$ were synthesized by sol process and adding the base, ITiO(Indium Titanium Oxide) particles were obtained by gelling at $200^{\circ}C$ and $500^{\circ}C$. The ITiO particle's size with gel process at $200^{\circ}C$ was smaller than ITiO particle's size with gel process $500^{\circ}C$. The ITiO particle with gel process at $200^{\circ}C$ was used to fabricate dense ITiO target. ITiO targets with 0.5, 1.0, 1.5 wt% of $TiO_2$ were fabricated and used to obtain ITiO thin films onto glass by sputtering. Among those sputtered ITiOs' thin films, ITiO thin film with 0.4 % of $O_2$ and 0.5 wt% of $TiO_2$ showed the lowest specific resistance, highest charge mobility and lowest carrier concentration. It was found the light transmittance of the ITiO film were increased highly compared to light transmittance of ITO (Indium Tin Oxide) thin film over Infrared wavelength ranges.

Synthesis of CeO2/TiO2 core-shell Nanoparticles (CeO2/TiO2 코어-쉘 나노입자의 합성)

  • Mun, Young Gil;Park, Chang Woo;Kim, Sang Hern
    • Journal of the Korean Applied Science and Technology
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    • v.34 no.4
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    • pp.746-755
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    • 2017
  • In this study, $CeO_2/TiO_2$ nanoparticle with structure of core and shell was synthesized by growing $TiO_2$ onto the surface of $CeO_2$ according to hydrolysis of $Ti(SO_4)_2$. Reaction time, temperature, concentration of $CeO_2$ slurry, pH control of $Ti(SO_4)_2$ were optimized about synthesis of $CeO_2/TiO_2$ core-shell nanoparticle. It was found that optimal mole ratio range of $CeO_2:TiO_2$ was 1:0.2~1.1, the optimal concentration of $CeO_2$ slurry was 1 %, and the optimal reaction temperature was $50^{\circ}C$. The optimal concentration of $CeO_2$ slurry could be increased up to 10 % by adjusting the pH of $Ti(SO_4)_2$ to 1 using $NH_4OH$ and adding to $CeO_2$ slurry. If reaction was carried at $80^{\circ}C$ or higher, the separated $TiO_2$ particles were obtained instead of $CeO_2/TiO_2$ core-shell nanoparticles. The optimal reaction temperature was $50^{\circ}C$ at which good shaped core-shell structure of $CeO_2/TiO_2$ was obtained.

An Empirical Study on the Influence of Entrepreneurship of Franchisor's CEO on Franchisor's Performance (프랜차이즈 가맹본부 CEO의 기업가정신이 기업성과에 미치는 영향에 관한 실증연구)

  • Kang, Byung-Oh;Kim, Jin-Soo;Ahn, Sung-Sik
    • Journal of Distribution Research
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    • v.15 no.4
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    • pp.87-117
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    • 2010
  • 'Entrepreneurship' which means spirit or activity seeking new value by challenging boldly the uncertainty is one of the most important concept in 21st century business environment. Franchise Industry taking a relationship with distribution industry also needs entrepreneurship. As franchise industry consists of small and medium enterprises, the entrepreneurship of franchisor's CEO is important for the franchisor's growth. The purpose of this study is to analyze the factors influencing on the entrepreneurship of franchisor's CEO, and the effect of the CEO's entrepreneurship on franchisor's performance. For this purpose, this study set CEO's psychological characteristics, market characteristics, and social-institutional characteristics as independent variables, CEO's entrepreneurship as parameter variables, and franchisor's performance as dependent variables. And to analyze this study model, this study collected questionnaires from 152 franchisors' CEOs, and uses SEM(Structural Equation Modeling). As the result, 'CEO's Entrepreneurship' influenced on both 'Franchisor's Financial Performance' and 'Franchisor's Non Financial Performance'. The results of this study provide some guides for franchisor's CEO and government policies.

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A Study on Consumer's Preference on Private Brand and National Brand by Characteristics (유통업체 브랜드(PB)와 제조업체 브랜드(NB) 상품의 속성별 소비자 선호 분석)

  • Hwang, Seong-Hyuk;Ku, Ja-Seong
    • Journal of Distribution Research
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    • v.13 no.4
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    • pp.47-70
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    • 2008
  • The purpose of this study is to find out characteristic of a product which has the most influence when consumer makes a purchase, and analyze if actual consumers make a purchase with recognition of the brand difference between PB and NB brands using conjoint analysis. As a result, the main factor which consumers consider when they purchase a product is the quality but the factor for brands (NB or PB) do not have an effect on their purchasing. The reason why consumers little consider a factor for PB or NB is that they do not have much knowledge of PB and they recognize the PB as a "me-too" product of NB. Therefore, retailers should develop more differentiated product in order to be recognized by consumers.

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