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        검색결과 251

        61.
        2018.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This study deals with the microstructure and tensile properties of 700 MPa-grade high-strength and seismic reinforced steel bars. The high-strength reinforced steel bars (600 D13, 600 D16 and 700 D13 specimens) are fabricated by a TempCore process, while the seismic reinforced steel bar (600S D16 specimen) is fabricated by air cooling after hot rolling. For specimens fabricated by the TempCore process, the 600 D13 and 600 D16 specimens have a microstructure of tempered martensite in the surface region and ferrite-pearlite in the center region, while the 700 D13 specimen has a microstructure of tempered martensite in the surface region and bainite in the center region. Therefore, their hardness is the highest in the surface region and shows a tendency to decrease from the surface region to the center region because tempered martensite has a higher hardness than ferrite-pearlite or bainite. However, the hardness of the 600S D16 specimen, which is composed of fully ferritepearlite, increases from the surface region to the center region because the pearlite volume fraction increases from the surface region to the center region. On the other hand, the tensile test results indicate that only the 700 D13 specimen with a higher carbon content exhibits continuous yielding behavior due to the formation of bainite in the center region. The 600S D16 specimen has the highest tensile-to-yield ratio because the presence of ferrite-pearlite and precipitates caused by vanadium addition largely enhances work hardening.
        4,000원
        62.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        선박 축계는 프로펠러 하중의 영향으로 선미관 후부베어링의 국부하중 증가가 현저히 나타나 축계 선미관 베어링 손상의 위험이 증대된다. 이를 방지하기 위해 수행된 추진축계 정렬연구는 주로 준정적 상태(quasi-static condition)에서 축과 지지베어링간의 상대적 경 사각을 감소시키는데 중점을 두어 진행되어 왔다. 그러나 보다 상세한 평가를 위해서는 동적상태를 추가로 고려하는 것이 필요하다. 4,70 0 DWT 선박을 대상으로 NCR로 운전중 급속으로 우현 전타할 때 추진축계가 받는 영향에 대해 연구하였다. 연구결과 선미 유동장 변화 에 의해 프로펠러 편심추력이 과도 상태가 되어 프로펠러에 불평형 진동이 유발되는 것을 확인하였다. 우현 전타시의 프로펠러 편심추력은 NCR 조건대비 축을 선미관 베어링으로부터 들어 올리는 힘으로 작용하여 선미관 베어링 하중완화에 기여하고 있음을 확인하였다.
        4,000원
        63.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate attention restoration effects provided by Seoullo 7017, an elevated public skygarden newly transformed from a 40-year-old overpass as a part of an urban revitalization project. In October 2017, a questionnaire survey utilizing Perceived Restorativeness Scale (PRS) and Zuckerman Inventory of Personal Reaction Scale (ZIPERS) was conducted among employees visiting Seoullo 7017 and 133 valid responses were collected. From a series of factor analyses of PRS and ZIPERS items, four PRS factors were derived from 16 PRS items and named as “Diversion”, “Boring”, “Coherence” and “Compatibility”; and two ZIPERS factors were extracted from twelve ZIPERS items, namely “Positive impacts” and “Negative impacts”. Significant differences in restoration effects and psychological stress were found according to frequency of visits, accessibility, and whether or not Seoullo 7017 was seen from offices. In conclusion, the newly created Seoullo 7017 was found to have healing effects, such as psychological stability and relief from stress, on employees who could easily access the garden.
        4,000원
        65.
        2018.05 구독 인증기관·개인회원 무료
        The main objective of this research study is the performance evaluation of 40/50 and 60/70 binder for asphalt mixtures in Vietnam. To accomplish the objective of this research, a dense gradation with nominal maximum aggregate size of 19.0mm is used for the asphalt mixtures. Marshall Stability (MS) test, Tensile Strength Ratio (TSR) test, Wheel Tracking (WT) test, and Dynamic modulus test are conducted to evaluate the rutting and cracking performance of 40/50 and 60/70 binder in asphalt mixtures. It was found that the Marshall stability of asphalt mixtures using 40/50 binder is about 12% higher than asphalt mixtures using 60/70 binder while the rutting resistance of the mixtures with 40/50 binder shows 2.5 times higher than 60/70 binder at 15,000 load cycles. Moreover, the TSR of asphalt concrete using 40/50 binder and 60/70 binder are approximately 95% and 79%, respectively which means that using 40/50 binder is very good for moisture damage resistance. Finally, the dynamic modulus test was done at a reference temperature of 20oC and frequency of 1,0Hz. The dynamic modulus of asphalt mixture with 40/50 binder is about 6257 MPa, which is two times higher than asphalt mixture using 60/70 binder. Based on the results of this study, it can be concluded that asphalt mixtures using 40/50 binder can improve the rutting and moisture damage resistance of asphalt concrete under high temperatures and moisture conditions significantly. It is noted that these conclusions were based on only on a limited number of samples and conditions. Further studies must be conducted to investigate the effect of 40/50 binder on fatigue cracking of asphalt pavement in the field.
        67.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문은 1970년 아시아에서 최초로 개최된 일본만국박람회(日本万国博覽會)와 전위예 술에 대해 살펴보았다. 일본만국박람회를 국가 이미지를 표상하는 문화외교 정책을 위한 장으 로 파악하고 기존의 일본의 전후 미술사에서 잘 다뤄지지 않거나 지엽적으로 서술되는 데 그친 ‘환경(環境)’ 담론 및 테크놀로지를 강조한 환경예술의 예술가 협업 그리고 구타이미술협회의 후 기 활동에 해당하는 일본만국박람회 출품작에 대해 검토하였다. 여기서 테크놀로지를 이용한 전위예술 경향은 과학기술의 발전이라는 측면을 제시하였으며 이는 진보, 미래와 동일시되어 이를 강조하는 정부당국의 방향성과 합치되는 면이 있었던 것으로 보인다. 일본만국박람회에서 전위예술은 일본이 고미술 등의 전통 뿐 아니라 현대미술에 있어서도 문화대국으로서의 면모를 지니고 있음을 알리고자 했던 정부당국의 의도를 실현시키는 역할을 하였다고 볼 수 있다.
        8,400원
        68.
        2017.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We measured the target strength according to the swimming tilt angle and size change for Pacific herring at the frequency of 70 kHz as the basic database in order to estimate its abundance as well as density in the survey area using the hydroacoustical method. The number of the sample used in this study was 14 individuals, and its size distribution by fork length ranged between 20.3 and 29.8 cm and wet weight was measured between 187.6 and 269.9 g. The variation of TS according to the swimming angle (-30~30°) was measured between 10.3 and 18.8 dB in frequency range, the highest value was measured at head-down of Pacific herring in the tilt angle range between 5 and 9 deg. of its swimbladder. The relationship between TS–FL of herring was the same as TS = 20log10 (FL) – 66.79 when its swimming tilt angle in the daytime (3.8 ± 6.0°) and nighttime (-3.2 ± 13.6°), respectively.
        4,000원
        70.
        2017.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The effect of strain aging on the tensile properties of API X70 linepipe steel was investigated in this study. The API X70 linepipe steel was fabricated by controlled rolling and accelerated cooling processes, and the microstructure was analyzed using optical and scanning electron microscopes and electron backscatter diffraction. Strain aging tests consisting of 1% pre-strain and thermal aging at 200 oC and 250 oC were conducted to simulate U-forming, O-forming, Expansion(UOE) pipe forming and anti-corrosion coating processes. The API X70 linepipe steel was composed of polygonal ferrite, acicular ferrite, granular bainite, and bainitic ferrite whose volume fraction was dependent on the chemical composition and process conditions. As the thermal aging temperature increased, the steel specimens showed more clearly discontinuous type yielding behavior in the tensile stress-strain curve due to the formation of a Cottrell atmosphere. After pre-strain and thermal aging, the yield and tensile strengths increased and the yield-to-tensile strength ratio decreased because yielding and aging behaviors significantly affected work hardening. On the other hand, uniform and total elongations decreased after pre-strain and thermal aging since dislocation gliding was restricted by increased dislocation density after a 1% pre-strain.
        4,000원
        72.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To evaluate the anti-oxidant and anti-tumor potential of the green pepper (Capsicum annuum L. cv. DangZo), total polyphenol content, radical scavenging activities and anti-tumor properties were measured. The total polyphenol content of the 70% ethanol extracts from green pepper (Capsicum annuum L. cv. DangZo) was 30.29 mg gallic acid equivalent/g extract. The DPPH radical and hydroxyl radical scavenging activities of 70% ethanol extracts of green pepper (Capsicum annuum L. cv. DangZo) were documented at 2.87 and 10.55, respectively. For α-glucosidase and α-amylase inhibitory activity, 70% ethanol extracts of green pepper (Capsicum annuum L. cv. DangZo) were documented at 35.67% and 58.41% respectively. The green pepper (Capsicum annuum L. cv. DangZo) demonstrated greater capability in terms of anti-neoplastic activity vis-a-vis colon cancer cell lines when compared to other cancer cell lines.s. er (Capsicum annuum L. cv. DangZo) higher activities of anticancer activities on colon cancer cell lines compared to other cancer cell lines.
        4,000원
        73.
        2017.10 구독 인증기관·개인회원 무료
        This study is investigated the growth characteristics(number of available stipe, pileus diameter, pileus thickness, stipe length, stipe thickness, object weight, comparison yield ability of 1 cycle) and storage characteristics of ‘Sanjo 701’ (S7) cultivars according to relative humidity. The S7 growth characteristics were investigated by quantifying the growth and the characteristics according to the relative humidity, The storage stability was investigated every 5 days and freshness was measured by ‘Minamide Method’. S7 pileus diameter is The higher the relative humidity was confirmed becomes larger and the more increased relative humidity also increase the comparison yield ability of 1 cycle. However, pileus diameter or stipe length This could not see the big difference in the three treatment groups, the plieus thickness was no significant difference in the treatment of 80% and 95%. The fresh weight of S7 decreased significantly at 80% and 95% relative humidity after 10 days of storage, but decreased continuity in 65% humiditiry. The elongation percentage of S7 pileus was observe in 95% relative humidity, values of L, a and b (SCI), showed the highest L value in 65% and the a value in 95%. b values were similar in 65%, 80% and 95% treatments. On the ‘Minamide Method’ measure freshness was changed from the 10th day of storage at relative humidity of 95%, but humidity of 65% and 80% treatments, it changed after 15 days of storage. In this study growth characteristics and yield were increased at higher relative humidity, but storage stability was decreased. Therefore, it is deemed necessary to change the relative humidity to produce high quality mushrooms.
        74.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We investigate that the impact of freshwater organism exposed to the salinity environment by the frequent rainfall following climate change. To evaluate the stress response following salinity exposure, we assessed the survival rate, molting success rate, the developmental period and mouthpart deformities in Chironomus riparius. In addition, we measured the molecular responses of biomarker gene, gene expression of heat shock protein 70 (HSP70) in C. riparius exposed to salinity after 96 hour. The C. riparius survival rates were showed on time dependent manner and not observed survival organisms above 15 psu at day 4. The pupation and emergence of C. riparius were not seen above 15 psu, and the molting success rate was less than 20% at 10 psu. The developmental retardation of C. riparius was well observed in the pupation and emergence period and was delayed by 4 days at 10 psu compared to the control and 5 psu. The mouthpart deformities after salinity exposure at 96 or 72 hour were observed at 10 psu and 15 psu. The expression of C. riparius HSP70 level was significantly increased exposure to 5 psu and 10 psu. Thus, salinity has been caused to be various ecotoxicological and molecular stress responses on freshwater organisms similar to harmful substances such as EDCs and so on.
        4,000원
        76.
        2017.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Multidrug resistance (MDR) remains one of the most significant obstacles in various cancer treatment, and this process often involves dysregulation of the number of micro-RNAs. The aim of this study was to explore the role of miR-4708 on the regulation of MDR-1 expression and the regulation of multidrug resistance (MDR) to chemotherapeutic drugs. Luciferase reporter assays demonstrated that miR-4708 directly binds MDR-1 3’-UTR and down-regulated reporter luciferase activity. The mRNA and protein expression levels of MDR1 were significantly decreased following miR-4708 overexpression. Additionally, the accumulation of rhodamine-123 in paclitacel resistant FaDu cells following miR-4708 transfection was significantly increased compared with control, indicating that the efflux capacity was reduced. These results demonstrated that miR-4708 could be involved in the regulation of MDR via targeting MDR-1 and may provide a potential strategy for reversing drug resistance in oral cancer.
        4,000원
        77.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study evaluated the mechanical joining characteristics of substrate Al7075 using the filler metals of ER5356 and Al7075 to secure the joining integrity of the specimens by GTAW. The results of radiographic test show that the welded specimens meet the first level standard of KS D 2042. Besides, welding defects were not occurred. The tensile strengths of the specimens using the filler metals of Al7075 and ER5356 had 240MPa and 252MPa, respectively. The yield strengths were 132MPa and 120MPa, respectively. In case of using the filler metal of Al7075, However, in case of using the filler metal of ER5356, Two filler metals of Al7075 and ER5356 were similar to each other in tensile and yield strength.
        4,000원
        78.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Although it has been well known that the Saemaul Undong had a direct relation with the water resources development during 1970’s, its contribution to the water resources and increased income in rural communities has not been thoroughly quantified so far. In order to assess the contribution of the Saemaul Undong in terms of rural water resources development, we investigated various historical data produced by the central and local governments in relation to water resources development. The results show the direct and indirect contribution of the Saemaul Undong to the water resources development in rural communities such as sewage works, water supply facilities, shared wells, and river works. The results also showed a positive relation between per-house income in rural communities and areas of irrigated paddies, which were rapidly increased during 1970’s. These results can be utilized to transplant the positive aspect of the Saemaul Undong to developing countries focusing on water resources development in rural areas.
        4,000원
        79.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        연구자는 1960년대 후반, 한국의 미술가들이 자신의 신체를 이용하여 퍼포먼스에 대한 실험 성을 펼친 사례를 청년작가연립전에 참여한 작가들이 시도한 해프닝, 1970년대 중반의 이건용 과 이강소를 중심으로 살펴본다. 한국의 퍼포먼스 아트에서 처음으로 신체를 ‘매개’로 사용한 점 을 분석하며 예술가의 몸과 일상을 서로 중재해 나가는 예술적 과정과 실천을 검토한다. 초기 한국 의 퍼포먼스 아트에서 정강자와 같은 여성 퍼포머를 바라보는 방식, 이건용의 ‘로지컬-이벤트’에서 는 언어의 개념과 상황을 매개하는 예술가의 몸과 타자성, 이강소의 1973년 <선술집>을 설명한다. 1960-70년대 한국의 퍼포먼스 아트는 미술가들의 신체가 갖는 불확정성, 비결정성을 중심으로 처음으로 ‘미술가의 몸’을 중요한 개인, 사회, 정치적 사이트라는 문화적 (콘)텍스트로 인식하는 한 국 아방가르드의 특징을 구축했다.
        8,100원
        80.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In 2010, a new variety for sawdust cultivation,was produced by monokaryotic-monokaryotic crossing between Sanjo 701ho and FMRI0995. The optimum temperature for Sanjo 708ho mycelial growth was 25oC; mycelial growth on potato dextrose agar was 51.6 mm over 7 days. The fruiting pattern was sporadic, and the optimal temperature range for fruiting was 5~20oC. Regarding fruiting body characteristics, the pileus was 65.8 mm in size, 16.1 mm in thickness, and hemispherical in shape. The stipe was 42.6 mm in and 19.6 mm in thickness. Mproductivity was good during thelow-temperature period from autumn to spring, with an average productivity of 310.7 g/bag.
        3,000원
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