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        검색결과 5,455

        281.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The emergency diesel generator of a nuclear power plant is a emergency AC power source that starts up within 10 seconds when a LOOP(Loss Of Off-site Power) occurs and supplies power to essential safety facilities. In this study, factors affecting start signal input time, engine rotation start time, 30% of engine rated speed, 80% of engine rated speed were studied to secure starting reliability. As a result, it was found that the section before the 30% of engine rated speed was affected by the mechanical management status from the start signal to the fuel oil linkage system. After the 30% of engine rated speed section, it was the maximum fuel supply section, and the time reduction effect through management improvement was insignificant.
        4,000원
        282.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A Emergency Diesel Generator(EDG) in Nuclear Power Plant supplies electrical power to reactor cooling system when on/off site power is lost. So that protect the reactor from melting down. A Emergency Diesel Generator is required to reach ±2% of rated frequency(rotational speed) within 10 sec. To achieve prompt start, it is needed to find out affective factors and effect of that during starting period. This paper describes case of fail to achieve starting requirement and improvement of starting performance.
        4,000원
        283.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        우리나라의 '해양오염방제 자재·약제의 성능시험기준 및 검정기준 중 ‘생물에 대한 영향시험’(생태독성시험)의 시험방법과 판정 기준의 개정과 관련한 방향을 제시하기 위해 현행 기준의 문제점을 파악하고 국가별 제도 비교를 통한 개선방안을 제시하였다. Skeletonema costatum을 이용한 성장저해시험의 경우, 배양액 색조를 비교하여 판단하는 기준 대신 측정된 성장률을 적절한 통계기법을 이용하여 비교 분석하는 과학적인 기준이 도입되어야 하며 시험기간의 경우, 지수성장기를 고려하여 4일 이내가 합당한 것으로 판단된다. 어류를 이용한 독성시험의 경우, 다양한 물질에 대한 독성시험 및 비교연구를 통해 방제 자재에 대해 일관되고 적절한 민감도를 나타낼 수 있는 보다 적절한 어체크기에 대한 재설정이 필요하고 이에 따른 합리적이고 객관적인 판정기준이 마련되어야 할 것으로 판단된다. 시험종의 경우, Artemia sp. 대신 해양 윤충류인 Rotifer, Brachionus plicatilis가 대안이 될 수 있으며 어류시험의 경우, 굴류(Oyster)와 같은 이매 패류의 분류군을 이용한 독성시험으로의 대체 역시 대안으로 고려될 수 있다. 마지막으로 해양오염방제 자재·약제의 형식승인 시험과 관련하여 생태독성시험 분야의 경우, 업무의 특수성과 결과의 신뢰성을 고려하여 별도의 공인시험기관 지정 또는 관련 유사 법률과 연계한 일원화된 창구가 필요하며 수용가능한 수준의 시험비용 산정과 시험항목 조정을 통한 합리적인 제도개선이 필요할 것으로 판단된다.
        4,000원
        284.
        2021.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        For the purpose of manufacturing a high efficiency TiO2 photocatalyst, B-doped TiO2 photocatalysts are synthesized using a plasma electrolytic oxidation method in 0.5 M H2SO4 electrolyte with different concentrations of H3BO3 as additive. For the B doped TiO2 layer fabricated from sulfuric electrolyte having a higher concentration of H3BO3 additive, the main XRD peaks of (101) and (200) anatase phase shift gradually toward the lower angle direction, indicating volume expansion of the TiO2 anatase lattice by incorporation of boron, when compared with TiO2 layers formed in sulfuric acid with lower concentration of additive. Moreover, XPS results indicate that the center of the binding energy peak of B1s increases from 191.45 eV to 191.98 eV, which suggests that most of boron atoms are doped interstitially in the TiO2 layer rather than substitutionally. The B doped TiO2 catalyst fabricated in sulfuric electrolyte with 1.0 M H3BO3 exhibits enhanced photocurrent response, and high efficiency and rate constant for dye degradation, which is ascribed to the synergistic effect of the new impurity energy band induced by introducing boron to the interstitial site and the improvement of charge transfer reaction.
        4,000원
        285.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the content of water-soluble vitamins such as vitamin B1 (thiamin), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B7 (biotin), B12 (cyanocobalamin), and C (ascorbic acid) in dishes containing meat and seafood consumed in Korea were determined by high-performance liquid chromatography (HPLC) with ultraviolet and fluorescence detection. All analyses were performed under strict quality control of vitamins B1, B2, B3, B5, B6, B7, B12, and C. The highest content of vitamin B1 was observed in Bugeo-gangjeong (1.373 mg/100 g) and the highest level of vitamin B2 (5.162 mg/100 g) was found in pig liver. Bugeo-gangjeong showed the highest content of vitamin B3 (21.676 mg/100 g), and kkomak-muchim contained considerable amounts (43.310 mg/100 g) of vitamin B5. Vitamin B6 was not detected in most seafood dishes except for yangnyeom myeongran-jeot (0.274 mg/100 g) and was present at low levels or not present at all in meat dishes. The highest content of vitamin B7 was 6.506 μg/100 g in saeu-jeon and kkomak-muchim showed the highest content (21.132 μg/100 g) of vitamin B12. The highest content of vitamin C was in yangnyeom myeongran-jeot (84.508 mg/100 g). In addition, the analysis methods of each water-soluble vitamin were verified. These results showed that seafood-based ingredients in several dishes could be a good source of water-soluble vitamins.
        4,000원
        286.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In recent years, there has been an increase in the morbidity of gastritis in Korea due to lifestyle factors mostly changes in eating habits and stress. Gastritis is more likely to progress to gastric cancer, and therefore it is important to prevent and manage gastritis through lifestyle adjustment and treatment at an early stage. In this study, cabbage, which was found to be effective in gastritis, was mixed and fermented with other crucifer plants such as kale and broccoli to evaluate the overall efficacy of fermented brassica puree on alcoholic acute gastritis. Based on our results, fermented brassica puree alleviated gastric injury induced by 150 mM HCl/60% ethanol. In addition, it was confirmed that PGE2, a gastric mucosal protective factor, was increased, and other positive effects such as an increase of MUC1 and regulation of PKC were observed. The results of this study suggest that fermented brassica puree can relieve acute alcoholic gastritis by regulating PGE and the expression of MUC1, a gene related to mucus secretion, and activating PKC, which is related to mucosal cell activity.
        4,000원
        287.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study analyzed the nutritional composition (proximate composition, total dietary fiber, calories, minerals, fatty acids, and amino acids) of 10 noodle products (tteok ramyun, jjamppong ramyun, kimchi ramyun, instant udon, cup ramyun, jajangmyun, bibimmyun, cream spaghetti, ssalguksu, and milmyun), which account for 85% of the cumulative intake of one or more key nutrients, using data from the 7th Korea National Health and Nutrition Examination Survey. The moisture contents of bibimmyun, jajangmyun, and cream spaghetti were lower than those of the other noodle products, whereas the crude fat, crude protein, carbohydrate, and calorie contents were the highest. Cream spaghetti had the highest mineral, fatty acid, and amino acid contents, followed by bibimmyun and jajangmyun. Ssalguksu had the lowest contents of most nutrients. These data could be used to populate a food composition database, which can provide consumers with the nutritional information about frequently consumed noodle products.
        4,000원
        288.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        지역적인 규모에서 식물다양성의 보전을 위해서는 기초적인 정보가 바탕이 된다. 조사의 결과로 나타나는 식물의 종수는 조사의 면적과 조사지역 내에 분포하는 다양한 생육지의 수와 밀접하게 연관된다. 경상북도 울진군의 마룡산과 대소산 일원에서 각각 9회와 6회에 걸쳐 식물자원을 조사하였다. 조사경로에 다양한 생육지가 포함되도록 계획하였다. 조사의 결과로 마룡산 일원에서는 112과 349속 548종 10아종 34변종 2품종 594분류군이 대소산 일원에서는 89과 270속 400종 9아종 25변종 434분류군이 조사되었다. 21개의 생육지로 구분하여 관찰된 식물을 정리하면 계곡주변의 전이대에 분포하는 식물과 건조한 초원에 분포하는 식물이 높은 비율을 차지하였다. 해안에 위치한 전통적인 묘지는 식물의 주요한 분포지로 기능하였다. 2개 지역에서 한국고유종은 19분류군이 조사되었다. 2개 지역에서 식물구계학적 특정식물종은 Ⅴ등급이 1분류군, Ⅳ등급이 11분류군, Ⅲ등급이 24분류군이 조사되었다. 귀화식물은 총 77분류군이 조사되었고 그중 생태계교란외래식물은 4 분류군이 분포하였다. 마룡산 일원과 대소산 일원에 분포하는 식물에서 나타나는 차이는 먼저 조사지역 내에 분포하는 각각의 생육지 크기 차이에 따른 것으로 판단되었다. 또한 대소산 일원이 주변의 산지와 연결되어 있지 않고 주거지와 경작지에 둘러싸인 고립된 공간에 해당하였기 때문으로 판단되었다.
        9,300원
        289.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Oxide dispersion-strengthened (ODS) steel has excellent high-temperature properties, corrosion resistance, and oxidation resistance, and is expected to be applicable in various fields. Recently, various studies on mechanical alloying (MA) have been conducted for the dispersion of oxide particles in ODS steel with a high number density. In this study, ODS steel is manufactured by introducing a complex milling process in which planetary ball milling, cryogenic ball milling, and drum ball milling are sequentially performed, and the microstructure and high-temperature mechanical properties of the ODS steel are investigated. The microstructure observation revealed that the structure is stretched in the extrusion direction, even after the heat treatment. In addition, transmission electron microscopy (TEM) analysis confirmed the presence of oxide particles in the range of 5 to 10 nm. As a result of the room-temperature and high-temperature compression tests, the yield strengths were measured as 1430, 1388, 418, and 163 MPa at 25, 500, 700, and 900oC, respectively. Based on these results, the correlation between the microstructure and mechanical properties of ODS steel manufactured using the composite milling process is also discussed.
        4,000원
        290.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As the frequency of seismic disasters in Korea has increased rapidly since 2016, interest in systematic maintenance and crisis response technologies for structures has been increasing. A data-based leading management system of Lifeline facilities is important for rapid disaster response. In particular, the water supply network, one of the major Lifeline facilities, must be operated by a systematic maintenance and emergency response system for stable water supply. As one of the methods for this, the importance of the structural health monitoring(SHM) technology has emerged as the recent continuous development of sensor and signal processing technology. Among the various types of SHM, because all machines generate vibration, research and application on the efficiency of a vibration-based SHM are expanding. This paper reviews a vibration-based pipeline SHM system for seismic disaster response of water supply pipelines including types of vibration sensors, the current status of vibration signal processing technology and domestic major research on structural pipeline health monitoring, additionally with application plan for existing pipeline operation system.
        4,800원
        291.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        구조물의 지진 피해 감소를 위한 내진 시스템 중에서 면진 시스템은 효율적으로 내진 성능을 향상시킬 수 있는 구조 시스템이다. 면진 시스템은 지반과 구조물을 분리시키는 만큼 안전성이 뛰어나지만, 사용되는 장치의 계열에 따라 연직 및 수평 하중에 대한 지지력과 요구변형량에 대한 복원력이 부족하여 파손이 발생할 수 있다. 본 연구에서는 면진 시스템의 성능 개선을 위해 기존 연구에서 제안한 면진 장치의 지지력과 복원력을 향상시킨 고무 마찰 베어링 장치에 대하여 실험 및 해석을 통한 성능 검증 연구를 수행하였다. 이를 위해 고무 마찰 베어링 장치의 설계 상세를 재정립하고 요구 성능에 따른 구조 실험을 수행하여 장치 특성을 검증하였다. 또한, 실험 결과의 신뢰성 향상을 위한 유한요소해석을 수행하여 실험 결과와 유사한 성능 수 준의 장치 특성을 확인하였다.
        4,000원
        292.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Don-am district is a residential area that was supplied in 1936 as a land readjustment project(Tojiguhoekjeongri). The Don-am district was newly supplied with residential areas and urban hanoks were built in large numbers. The Don-am district was influenced by urban planning and legislation at that time. These affected in the layout and plan of urban hanok. Residential block in the Don-am district were developed sequentially from the late 1930s to the 1960s. Residential block were divided by modern construction company and sold by individual lots. The blocks supplied to the Don-am district made uniformly the corner out-off(Ga gak) for creating a vehicle-centered road. So urban hanoks located in the corner plot was transformed in response to the road. Residential blocks in Don-am district was divided into three to four rows. Therefore, alleys were created inside the block. Newly made alleys consist of a privately owned road(Sa-do), a public road(Gong-Do), and open space in the site. And the alleys were used as an entry space for sharing with neighboring. Urban hanoks of Don-am district have had changed and adapted to the formation of these alleys.
        4,600원
        299.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 한국어 대인관계 단어 도구를 제작하는 것으로, 그 첫 과정으로서 대인관계 단어 목록에 포함시킬 적절한 단어를 수집하는 것이 매우 중요하다. 먼저, 생소하지만 의미를 짐작해볼 수 있고 대인관계를 나타내는 것으로 판단되는 모든 어휘를 3종의 국어사전으로부터 수집하였다. 그 결과, 총 2,725개의 단어로 구성된 대인관계 단어 총집을 제작하였 고, 중복되는 단어를 선별하여 총 910개의 단어를 선정하였다. 그 중에서도 문법적인 형태가 다를 뿐, 의미가 비슷하거 나 동일한 단어가 발견되어 이를 반영한 재분류 작업이 요구되었다. 이러한 절차는 총 7회 반복하여 실시하였으며 그 결과, 총 249개의 단어를 선별하였다. 한편, 대표 단어 도구를 개발하는 본 연구의 특성 상, 단어의 의미가 보다 구체화되고 집약되어 전체적인 대인관계 양상을 하나로 잘 나타낼 수 있는 단어 구성이 필요하므로, 단어의 수를 축약시킬 필요가 있었다. 따라서 단어 선별의 마지막 단계로, 앞서 추출한 총 249개의 대인관계 단어에 대한 친숙성과 적절성 평가에 따라 재선별하는 절차를 수행한 후, 친숙성과 적절성의 평정치 결과가 서로 공통적으로 가장 높게 나타난 단어들을 최종적으로 선별하였다.
        6,100원
        300.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Since its construction in the late 14th century, Hanyangdoseong had been carried out three major repairs and reconstructions during the 500 years of the Joseon Dynasty. In addition to the large-scale construction, small-scale construction continued until King Gojong era. In particular, in the 18th century, systematic construction management was implemented by the craftsmen and the military participated in the renovation of Hanyangdoseong in earnest, and the construction methods also developed rapidly. In the early 18th century, new construction techniques were attempted in various sections of the reconstruction work, and gradually became a common technology for repairing Hanyangdoseong in the late 18th century. The purpose of this study is to examine the characteristics and period of changes in the 18th century's construction technique, when the rapid development of Hanyangdoseong took place. To this end, the excavation results related to Hanyangdoseong, the remaining city wall, and the inscribed stones were used to identify and demonstrate the characteristics and change of the construction method.
        4,300원