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        검색결과 29

        1.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated how to repair high-pressure pipes by applying the expansion method instead of the welding method used to repair pipes in the steel, petrochemical, and shipbuilding industries that use high-pressure pipes, and developed a pipe-specific expansion device and auxiliary equipment to use the expansion pipe. We developed an expansion device with a range of 65A to 125A, evaluated the characteristics of the equipment, and manufactured high-pressure pipes made with this device, and obtained the following conclusions. The pressure resistance performance test of the non-welded expansion device was carried out at 32A to 125A, and the pipe pressure resistance test showed good results, and the durability test confirmed the durability of 0.0061 to 0.0063mm. The vibration test of the developed expansion device was measured at 0.3~0.5mm/s, and the noise measurement result was 65.1~65.5 at 32A, 65.2~65.5 at 65A, and 65.4~66.6dB at 125A.
        4,000원
        3.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was to develop a piston rod made of SiC by applying a sintering treatment after press molding in order to replace the imported piston rod used in the past. As a result of evaluating the mechanical properties of the developed piston rod, the following conclusions were obtained. The surface roughness value of the piston rod made of silicon carbide was 0.950Ra, and the surface Vickers hardness value was 19.94GPa. As a result of XRD analysis of the surface of the prototype piston rod, the main crystalline phase was 6H-SiC, and the crystalline phases of 4H-SiC and α-SiC were existed. In addition, a trace amount of SiC was detected. As a result of SEM observation of the piston rod surface of the prototype, a number of large porosity were observed. As a result of measuring the surface hardness of the piston rod made of SiC, it showed 70% of the physical properties compared to imported products.
        4,000원
        5.
        2019.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study has described as a way of establishing an automated system that allows sorting of living fish caught at sea by weight, and producing and testing as prototypes. The live fish that applied for this research is named as a croaker. 30(thirty) times of measurements with the fishes were applied for screening initially. As a results, it was the highest deviation rate of 19.7% within 2g of their initial weight. In addition, it showed the lowest deviation rate of 8.2% below 10g of them. Throughout the measuring experiments, it was found that the error that occurred during weighting was friction with the upper surface of the load cell on the circular sorting plate. Once the friction was removed, it was figured out that the average deviation in weight per each fish was measured as 0.76g. This error should be able to be eliminated by improving the material of machine elements, the surface material of the load cell. Under this circumstance, this pilot test in sorting living fishes by weight was brought adequate results. The existing sorting device was performed at 4,500 fishes per hour as a sorting speed. The sorting device developed in this research improved productivity by over 33% by setting the sorting speed in 6,000 fishes per hour.
        4,000원
        6.
        2018.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, attention has been focused on magnesium materials, which are widely used for lightening of electronic products and mobile phones. Therefore, a polishing apparatus was fabricated by replacing the SiC abrasive used for polished surface of magnesium plate with a ceramic abrasive. The following conclusions were obtained. It is believed that the increase in productivity of 50% compared to the conventional cross-sectional polishing due to the double-side polishing of magnesium sheet can contribute to increase the company's sales. The surface roughness was measured by polishing the plate using a magnesium plate mirror polisher. The Ra, Rmax and Rz values were 0.43, 0.54 and 0.54, respectively. In this study, the optimum polishing speed was 800 m/s when the surface was polished with a magnesium surface polishing device designed and manufactured as a prototype.
        4,000원
        7.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To achieve a sustainable competitive advantage, firm is required innovative activities and competences. However, Small and Medium sized Enterprises (SMEs) is hard to achieve a superior performance because they possess low competences. So, this paper identify determinants of innovation performance by firm size in motor and electronics industry based on a resource-based view. This paper analyzes the effects of innovation activities and competence on innovation performance by using firm-level data provided by Korea Innovation Survey (KIS). The empirical evidence presented shows that there are differences of determinants on innovation performance by industry and firm size.
        4,500원
        8.
        2014.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the quality characteristics of cookies containing capsaicin, the main source of spicy taste in pepper, which is well known for its various functions such as anti-oxidant, anti-cancer, anti-inflammatory, and anti-obesity activities, as well as pain-relief effect. Cookie samples were made by adding the capsaicin powder at different levels, including 40 mg% (C1), 85 mg% (C2), and 150 mg% (C3). In this study, measurement of the moisture, pH, color, spread factor, hardness, anti-oxidant activity, and sensory evaluation of the cookies was carried out. The results showed that the anti-oxidant activity increased when more capsaicin powder was added to the cookies (p<0.001). The moisture also increased with increasing capsaicin powder content (p<0.05), while the pH did not show any significant changes. As for the colors, the L value and b value decreased as more capsaicin powder was added, while the a value increased. The spread factor also increased significantly with the increase of capsaicin powder (p<0.01). Although the hardness increased with capsaicin powder content, no statistically significant differences were observed among the various cookies. In the sensory evaluation, Cookies containing 40 mg of capsaicin obtained the highest score in color, while cookies containing 150 mg of capsaicin showed the highest score in taste, texture, and overall acceptability.
        4,000원
        9.
        2014.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Aloe is an attractive potential food source because it has functional uses. It has been widely used as a well-being food and drink. The antioxidant activity was estimated by measuring DPPH free radical scavenging activity. We investigated the quality characteristics of cookies prepared by adding various concentrations of aloe powder (0%, 1%, 3%, 5%, all w/w) as a substitute for flour. In this study, the DPPH free radical scavenging activity, moisture content, and hardness of cookies significantly increased with increasing aloe powder, while the pH, spread factor and L and b values slightly decreased. Sensory evaluation scores in terms of texture were shown to be very similar statistically, but color, flavor, taste, and overall acceptability scores were lower than the control. As a result of this study, the quality of cookies with the addition of 1% aloe powder were the most suitable in terms of taste, flavor, texture, and sensory properties.
        4,000원
        10.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the quality characteristics of cookies containing mugwort powder, which is well known for its various functions and biological activity. Cookie samples were made by adding the mugwort powder at different levels of 0%, 1%, 3% and 5%. In this study, moisture, pH, color, spread factor, hardness, antioxidant activity and sensory evaluation of cookies were examined. The pH and moisture were increased when increasing levels of mugwort powder were used. The L, a and b color values were significantly (p<0.001) decreased when increasing levels of mugwort powder were used. The spread factor of the cookies was significantly (p<0.01) decreased when increasing levels of mugwort powder were used.. The hardness and DPPH radical scavenging activity of cookies were significantly (p<0.001) increased when increasing levels of mugwort powder were used. Cookies containing 3% of mugwort powder showed the highest taste and texture scores. The scores for Flavor and color decreased when more mugwort powder was added.
        4,000원
        11.
        2014.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Purpose of this study is to empirically examine the impact of various internal and external innovation activities of SMEs on their innovation performances in the field of electronics and communication industry. Drawing upon the literature review, internal and external innovation activities are defined and conceptualized, and independent, dependent and moderator variables are developed. We have used survey-based data for this study from the survey of technology innovation activities in manufacturing industry, which was conducted by the Science and Technology Policy Institute (STEPI) in 2010. The main result of this study shows that there were no significant differences in the impact of innovation activities on market performance according to the size of SMEs. On the other hands, we found that there were significant differences in the impact of innovation activities on technological innovation performance according to the size of SMEs. Therefore, in order to make high technological innovation performance, companies in the field of electronics and communication industry need to properly implement the internal and external innovation activities by considering their size.
        4,300원
        12.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 일본식으로 제조된 상업용 간장과 우리나 라 전통방식으로 제조된 재래식 간장으로부터 다당을 분리 하여 RAW 264.7 대식세포주를 이용한 면역 증진활성을 비교 하였다. 간장 유래 다당, CSP-0 및 KTSP-0는 RAW 264.7 세 포주에 대해 모든 농도에서 세포 독성을 나타내지 않았다. 또 한 재래식 간장 유래 다당인 KTSP-0는 상업용 간장 유래 다 당 CSP-0보다 대식세포에 의한 NO 및 ROS의 생산을 농도의 존적으로 증가시켰으며, KTSP-0를 1,000 ㎍/㎖ 처리하였을 시 가장 높은 생산능을 나타내었다. 간장 유래 다당의 RAW 264.7 세포로부터 면역반응에 중요한 cytokine인 IL-6와 TNF-α의 cytokine mRNA의 발현량과 해당 단백질의 생산을 각각 real-time PCR과 ELISA로 확인한 결과, CSP-0는 IL-6와 TNF- α mRNA의 발현 및 생산에 유의적인 영향을 미치지 않았지 만, KTSP-0는 농도의존적으로 IL-6와 TNF-α mRNA 발현 및 생산을 증가시키는 것을 확인하였으며, 1,000 ㎍/㎖ 처리 시 최대 활성을 보였다. 한편, 대식세포의 탐식작용에서 중요한 역할을 하는 Fc 수용체의 발현 증가를 RT-PCR로 확인한 결 과, CSP-0는 FcR I, II의 발현에 모두 영향을 미치지 않았지만, KTSP-0는 FcR I의 발현을 선택적으로 증가시킴이 확인되어 항원에 결합한 IgG와 강하게 결합하여 탐식작용을 촉진시킬 것으로 예상되었다. 본 연구를 통해 상업용 간장에서 분리한 다당, CSP-0보다 우리나라 전통 재래식 간장에서 분리한 다 당, KTSP-0가 대식세포를 활성화하여 높은 면역 증진 효과를 나타내는 것으로 결론 지을 수 있었다.
        4,000원
        13.
        2013.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To reproduce the brewing process of Hongkuk-ju and to identify the functional properties of it, Hongkuk-ju was brewed using different additions of Hongkuk (100%, 90%, 70%, 50%) and Nuruk (0%, 10%, 30%, 50%). The quality elements, including pH, total acidity, reducing sugar content, alcohol content and pigments (yellow, red, monacolin K and citrinin), were measured. The pH values of Hongkuk-ju showed a slight difference (pH 4.08~4.58) right after the 1st stage mash; further, the pH on all groups (H1, H2, H3 and H4) in the terminal of the 2nd stage mash (9 days in fermentation) were similar, ranging approximately at pH 3.70. The total acidity change did not show a difference directly the 1st stage mash (nearby 0.2 %); however, it began to show a slight difference at the terminal of the 2nd stage mash between the range of 0.69~0.76%. The residual reducing sugar of the content was decreased with the increased Nuruk content. The alcohol concentrations of the treatment brew with Nuruk ranging from 12.3% to 13.7% were higher than Hongkuk on its own. The yellow and red pigment contents of Hongkuk-ju ranged from 7.2~8.8 O.D. units (yellow pigment) and from 4.4~5.1 O.D. units (red pigment). The production of monacolin K and citrinin was the highest (9.48 ㎎/㎏ and 10.14 ㎎/㎏) when the treatment solely brewed Hongkuk. The concentration of Nuruk and the preparation of the seed mash from it were critical factors compared to the treatment of rice in brewing Hongkuk-ju
        4,000원
        14.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to produce Hongkuk-ju, the production and characterization of Hongkuk (Monascus red koji) by Monascus anka KCTC 6121 were investigated. The optimum cultural conditions for the production of enzyme (α-amylase and glucoamylase) and pigment (yellow and red) from this strain on solid culture (steamed rice) were examined. The results showed that the production of α-amylase and glucoamylase reached the highest for 9 days and 8 days, respectively. Since then, the productions decreased slightly. The production of yellow and red pigments reached the highest for 8 days, decreasing slightly soon after. The optimal content of the initial moisture equally presented 30% in the enzyme and pigment production. After that, the enzyme production decreased slowly, whereas pigment production decreased sharply. The optimal temperature of the culture also showed 30℃ in the production of enzyme and pigment. It was found that the initial inoculum size in enzyme and pigment production was 10% and 20%, respectively. Under these optimal conditions, the production of monacolin K and citrinin was 74.35 ㎎/㎏ and 5 ㎎/㎏ for 12 days, respectively.
        4,000원
        16.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Poly-γ-glutamic Acid(γ-PGA)를 다량 생산하는 균주를 우리나라의 전통발효식품인 청국장으로부터 Bacillus subtilis GS-2를 분리하였다. 이 균은 glutamic acid 의존형 균으로, 이 균에 의한 γ-PGA 생산 최적 조건을 검토한 바, 단순배 지(L-glutamic acid 2.0%, glucose 1.0%, NH4Cl 0.5%, KH2PO4 0.05%, MgSO4, 7H2O 0.01%, pH 7.0)로 진탕배양(220 rpm) 하였을 때, 배양시간 48시간, 최적온도 33℃, 그리고 초기 pH 6.5로 나타났다. 영양원으로 glutamic acid 3%, sucrose 3%, NH4Cl 0.25%, KH2PO4 0.15%, MgSO4, 7H2O 0.015%에서 γ-PGA 최대 생산량이 31.0 g/ℓ이었다. Key words: Chungkookjang, culture medium, poly(γ-glutamic acid), PGA, soybean paste
        4,000원
        17.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, ‘Social Commerce’ has shown such a rapid growth along with the development of social media such as ‘Twitter’ and ‘Facebook.’ Yet, with the quantitative growth, some problems regarding consumer dissatisfaction has constantly occurred. It is essen
        4,000원
        18.
        2011.06 구독 인증기관 무료, 개인회원 유료
        본 연구는 2009년 12월부터 2010년 7월까지 일반계 여고 40명, 일반계 남녀공학 40명, 예고남여공학 30명 학생들을 대상으로 전전두엽 뇌파측정 결과를 바탕으로 산출된 다양한 뇌기능분석과 뇌기능지수를 통해 예능계 고등학생들의 뇌 발달 특성과 정서 및 성향이 일반계 고등학생들과 차이점이 무엇인지 구체적으로 파악하였다. 목적에 따라 분석한 연구 결과는 다음과 같다. 첫째, 예능계 고등학생과 일반계 고등학생 간에 전전두엽 뇌파에서 몇 가지 범주에서 차이가 있었다. 둘째, 좌우뇌 균형에 있어 예능계 고등학생과 일반계 고등학생 뇌파에서 차이가 없었다. 셋째, 예능계 고등학생과 일반계 고등학생 간에 정서 및 성향에서 차이가 없었다.
        6,000원
        19.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Controlling industrial vehicle operated by human in warehouse was not simple since the information transfer for controlling the vehicle was not easy. However, as the technology for the WMS (Warehouse Management System) has been advanced and the PDA (Perso
        4,000원
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