검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 120

        81.
        2019.10 서비스 종료(열람 제한)
        본 연구에서는 플라이애시가 다량치환된 모르타르에 알칼리 활성화를 통한 강도증진을 양생온도 및 양생방법 변화에 따라 비교 분석하였다. 연구 결과로 플라이애시를 60 % 과다치환한 경우 소생재 도포 후 40℃의 온도로 48시간 기중양생을 실시한다면 OPC의 28일 압축강도에 근접하게 발휘되는 것이 얻어졌다.
        82.
        2018.12 KCI 등재 서비스 종료(열람 제한)
        In this study, daily precipitation data and daily average temperature data of meteorological observatories in Daegu, Busan, Daejeon, Seoul, Mokpo, and Gwangju cities inland and offshore were analyzed by using moving average method. Were compared. Overall, summarizing changes in precipitation and temperature over the 24 seasons, precipitation and temperature in all six stations increased compared to the past 1960s. In the case of precipitation, precipitation increased at the end of July and early August, whereas precipitation in April, September and early October decreased. In the case of temperature, especially in February, the temperature increased, and in Mokpo, the temperature from August to December showed a general decline. Changes in precipitation and temperature due to seasons in the 24 seasons affect agriculture and our everyday life, and further research is needed to determine how these changes will affect agricultural water supply, crop growth and daily life. The results of this study can be useful.
        83.
        2018.05 서비스 종료(열람 제한)
        Background : Platycodon grandiflorum has been used as famous medicinal vegetable and traditional medicine in Korea. Platycodon grandiflorum is used more for vegetable than it is used as a medicine. Proper storage conditons are required for distribution of Platycodon grandiflorum as vegetables. The purpose of this study was to find the appropriate storage temperature. Methods and Results : 2-years old Platycodon grandiflorum cultivated in Herbal Crop Research, RDA Eumseong was used. They were packed with plastic container box of 45 × 70 × 30 ㎝ and then stored at –2℃, 2℃, 5℃, 25℃, humidity 80 - 82%. During the storage, hardness, L a b values, weight loss, decay rate were measured every 30 days as quality indices. During the storage period, L value decreased but a and b values increased and same pattern was observed at all storage temperatures. Hardness decreased and same pattern was also observed at all storage temperature. Under constant humidity conditions, weight loss was larger at higher temperature. The higher the temperature, the larger the deviation at weight loss. There were little decay but 25℃ temperature stored showed that dacay rate was higher with time over. Conclusion : The favorable temperature for storage is –2℃ - 2℃ while maintaining constant humidity.
        84.
        2017.09 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to quantify the magnitudes of projected 21st century temperature changes and shifting climate zones over Mt. Halla, Korea based on high-resolution (1km×1km) climate change scenario data sets down-scaled from a global climate model (HadGEM2-AO) simulations using PRIDE (PRISM based Downscaling Estimation Model) as well as the simulations of a Regional Climate Model (RCM; HadGEM3-RA). The high resolution climate data demonstrate that the magnitudes of increases in coldest and warmest monthly mean temperatures over Mt. Halla will exceed those of the averages across the Korean Peninsula during the 21st century, leading to the shifts of climate zones. The isoline with 5°C (20°C) of the coldest (warmest) monthly average temperature associated with sub-tropical (sub-alpine) climate zones will migrate from 100~230m (950~1,300m) to 300~500m (1,300~1,600m) of altitude in the late 21st century (2071~2100) under the RCP 4.5 scenario. These changes are expected to be more obviously observed in the south flank of Mt. Halla as well as under the RCP 8.5 scenario. These results indicate that changes in climate zones will lead to the extinction of sub-alpine ecosystems over Mt. Halla due to increases of summertime heat stress as well as to the expansion of the sub-tropical forest zone toward mid-mountain regions due to reduction of wintertime stress in the warmer 21st century.
        85.
        2017.09 서비스 종료(열람 제한)
        In Korea, for about 2 months from late July to early September, it is expected that the average temperature will exceed 25 ℃, therefore, construction shall be conducted with hot weather concrete. In the case of the concrete placed at this time, if proper curing quality control measures are not established, problems such as plasticity, drying, shrinkage, and crack are caused. Therefore, in this study, an optimum method is proposed by mutually comparing the temperature history characteristics of the slab concrete in accordance with the change of surface coated curing material type.
        86.
        2017.06 KCI 등재 서비스 종료(열람 제한)
        At the Brain MRI examination, RF Pulse are irradiated on the human head in order to acquire MR images. At this time, a considerable part of the irradiated RF Pulse energy is absorbed in our body and the temperature of the human head will rise depending on the degree of exposure, so it will affect the human head. Even if the same RF Pulse energy is given, if the metal is inserted in the human head, the conductivity of the human head is greatly increased by the metal, so the SAR value increases and the temperature also rises. Therefore, we started this research with the question as to whether there is difference between the change in SAR value and temperature displayed on the head of the human according to use or not of the dental implant. Experiments were using the XFDTD program on a 128 MHz RF Pulse frequency by a 3.0 tesla MRI. We can see that both are increasing that the average value of SAR and temperature that absorbed by the human head model used the dental implant. In addition, the average maximum SAR value and the maximum temperature rise in the brain part are shown below the international safety standard value but the influence can not be ignored because of the result may change according to the increase in the number of dental implant. And as future tasks. we need to the simulation of temperature rise and SAR due to an increase in the number of implants and volumes of teeth, dental implant material.
        87.
        2017.04 서비스 종료(열람 제한)
        The spaces under bridge have been used as business zone and yard. The facilities and piles of goods under bridges are considered at high risk for fire danger. In this paper, CFD simulations were conducted to predict the temperature change beneath steel and concrete bridges due to fire in clothing boxes, frequently placed in the space under bridge. Based on these results, the relationship between the piled height of clothing boxes and the clearance of bridge, and temperatures beneath the bridge was derived using a Lagrange interpolation.
        88.
        2017.03 KCI 등재 서비스 종료(열람 제한)
        In this paper, for selected station of 8 clusters in East Asia (Park, 2017) more (less) warming periods than the wintertime mean warming of intra-seasonal fluctuation curves were taken and their means were computed. Long term trends and synoptic features of the mean temperature changes were examined. In most clusters, around the third of January there were less warming periods (LWP) than the mean wintertime warming. On the contrary, in February and the first and second of January there were more warming periods (MWP) than the winter mean or LWPs having a warming trend with statistical signicance. Time series of the daily Siberian High indices showed they had been weakening in February and being stagnant around late January. In most stations, the mean temperatures of MWP or LWP had large negative correlation coecients with the Siberian high intensity. is result explains the occurrences of MWPs in most clusters in February and LWPs in late January. In cluster B there were LWPs in early February due to the influence of the Aleutian Low which were strengthening in that periods. Cluster E showed different features without LWPs in late January. The cluster is considered to be affected by its plateau environment of West Yúnnán and the Tibet Plateau which prevent cold air of the lower atmosphere in Northern Asia flowing southward, and by the regional atmospheric circulation of 500hPa surface centered in this region.
        89.
        2017.03 KCI 등재 서비스 종료(열람 제한)
        In this study, the intra-seasonal fluctuation (ISF) of wintertime temperature change in East Asia was classified by a cluster analysis of complete linkage. A ISF of temperature change was defined as a difference of synthesized harmonics (1 to 36 harmonic) of daily temperature averaged for 30 years (1951~1980, 1981~2010). Eight clusters were gained from the ISF curves of 96 stations in East Asia. Regions of the cluster C, G and A1 seem to be affected by the Siberian High (SH) center, whereas the cluster A1, A2, D, B and F by the SH main pathways. Regions of the cluster E are apart from the SH main pathways and appear to be in the area of influence of other factors. Wintertime temperatures in Northwest China (clusters C, G) and Northeast China (cluster A1) were increased very largely. In most clusters, around late January there were less warming periods than the winter mean of the mean ISF of the clusters, before and after this time there were more warming periods than the winter mean.
        90.
        2017.01 KCI 등재 서비스 종료(열람 제한)
        The spaces under bridge have been used as business zone and yard. The facilities and piles of goods under bridges are considered at high risk for fire danger. In this paper, CFD simulations were conducted to predict the temperature change beneath steel and concrete bridges due to fire in clothing boxes, frequently placed in the space under bridge. Based on these results, the relationship between the piled height of clothing boxes and the clearance of bridge, and temperatures beneath the bridge was derived using a Lagrange interpolation.
        91.
        2015.10 서비스 종료(열람 제한)
        In this study, the heat insulating performance increase the indoor temperature of the building is applied to the concrete was compared with plain concrete. As a result, the indoor surface at the outside temperature of 10.4 ~ 22.4 ℃ temperature conditions showed a difference of up to 0.6 ℃, the lowest 0.6 ℃, indoor temperature is up to 0.2 ℃, 0.2 ℃ lower results showed a minimum.
        92.
        2015.10 서비스 종료(열람 제한)
        Experimental program was conducted for hydration heat evaluation of concrete using strontium based phase change material (PCM). Adiabatic temperature rise test was investigated for four days. In results, concrete with strontium based PCM has about 20 percent lower hydration heat than ordinary one.
        93.
        2015.08 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        본 연구에서는 부재료를 첨가하지 않는 건 블루베리를 제조기술을 확립하고자 건조 온도를 달리하여 건 블루베리의 품질변화와 항산화 특성을 조사하였다. 즉, 건 블루베리 제조는 건조 온도에 따라 A(40℃, 72시간), B(40℃, 48시간 및 50℃, 24시간), C(50℃, 72시간), D(60℃, 72시간)로 하였다. 건 블루베리의 수율을 측정한 결과 17.73~31.17%의 범위이었으며 건조 온도가 낮을수록 유의적으로 높게 나타났다(p<0.05). pH는 A가 가장 높았으며 가용성 고형분 함량은 건조 온도가 높을수록 유의적으로 높아지는 것으로 나타났다(p<0.05). 수분함량 및 수분활성도는 건조 온도가 높을수록 낮아지는 경향으로 나타났다. 색도를 측정한 결과 L값은 건조 온도가 낮은 A가 높게 나타난 반면 a값 및 b값의 경우는 건조 온도가 높은 D가 높게 나타났다. 건조된 건 블루베리의 색도는 건조 온도가 높을수록 건조는 빨리 되었지만 육안으로 보았을 때 과피의 색이 주황색으로 변하여 상품으로 적절하지 않았다. 조직감 변화는 경도(hardness), 점성(gumminess) 및 씹힘성(chewiness)은 건조 온도가 높을수록 높은 값을 나타내었으며 탄력성(springiness)과 응집성(cohesiveness)은 비슷한 경향으로 건조 온도가 높을수록 약간 증가하는 경향이었지만 유의적인 차이는 없었다(p<0.05). 관능적 특성에서 전반적인 기호도는 B > A > C > D순으로 평가되었다. 항산화 특성으로 총 폴리페놀 함량과 DPPH radical 소거능을 측정한 결과 건조 온도가 낮을수록 항산화 활성이 높게 나타났다. 따라서 건 블루베리 제조에 적당한 처리군은 B로 열풍건조 온도를 40℃로 하여 48시간 건조 후 온도를 50℃로 높여 24시간 동안 건조하는 것이 품질이 우수한 상품과 형성율을 높이는데 좋을 것으로 생각된다.
        94.
        2015.06 KCI 등재 서비스 종료(열람 제한)
        Climate change, in particular temperature change, has an impact on the demand for heating and cooling. This paper explores the effect of gradually warming climate on the demand for heating and cooling in Seoul during 1995-2014 using an autoregressive distributed-lag model, a family of timeseries econometric multivariate regression model. The estimated results reveal that there are two peaks in Seoul's electricity consumption because cooling degree days (CDD) and heating degree days (HDD) are statistically highly significant. CDD’s regression coefficient for a short and long-run model is approximately twice bigger than HDD’s and the summer peak is more important in terms of electricity consumption in Seoul. Furthermore, there exists a long-run relationship between electricity consumption and the explanatory variables such as economic growth, CDD, HDD, seasonal dummies, and black out dummy.
        95.
        2015.03 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to determine the stress response [ethological (operculum movement number (OMN)), hematological (hematocrit and hemoglobin), biochemical (glucose, cortisol and glutamic oxaloacetic transaminase (GOT))] in red spotted grouper, Epinephelus akaara during exposure of different water temperature in winter season. This species (Total length, 18.56±0.34 cm) previously maintained in water temperature of 15°C were transferred to 15, 20 and 25°C. During experimental period (7 days), OMN, hematocrit (Ht), glucose and GOT values were significantly high in 15°C when compared to 20 and 25°C. Hemoglobin value was also increased at 15°C, but no significant differences. There was no differences in cortisol levels among the temperature groups. No fish mortality was observed during the experimental period. From these results, 15°C is likely more stressful to red spotted grouper than 20°C and 25°C. These observations confirm that red spotted grouper adapts better to temperatures between 20 and 25°C during the winter season.
        96.
        2014.11 KCI 등재 서비스 종료(열람 제한)
        현재 전 세계적으로 석탄, 석유 등 화석연료의 사용으로 지구 온난화가 진행되고 있다. 이러한 원인으로 폭염, 폭설, 폭우 및 슈퍼태풍 등과 같은 이상기후, 극한기후 현상이 지속적으로 증가 하고 있다. 또한 심각한 자연재해로 콘크리트 구조물 및 사회기반시설의 심각한 손상과 붕괴가 발생한다. 이러한 문제들을 해결하기 위해서는 기후변화에 적합한 기준 및 시공 기술 등이 필요한 실정이므로 본 연구에서는다양한 온도와 습도 양생조건이 콘크리트 배합에 미치는 영향을 검토해 보았다. 다양한 온도와 습도 조건에서 양생된 콘크리트의 압축강도와 할렬인장강도 실험을 수행하였다. 또한 성능중심평가 (performance based evaluation (PBE))방법을 사용하여 다양한 양생조건에서 경화된 콘크리트 강도의 만족도확률을 평가하였다. 또한 콘크리트의 성능중심평가로부터 얻는 결과 값을 바탕으로 기후변화가 배합에 미치는영향을 고려하여 배합설계에 적용할 수 있다.
        97.
        2014.09 KCI 등재 서비스 종료(열람 제한)
        In this study, we analyzed the intraseasonal variability and change of winter temperature over South Korea using long-term observations. The lowest temperature in the wintertime, using daily mean, maximum, and minimum temperature data occurred on January 7th in the period of 2003~2012, while on January 22~25th in the past 30 years(1973~1982, 1983~1992, 1993~2002). Representative seven stations in South Korea also showed consistent result. The strengthening of Siberian High and weakening of Aleutian Low in recent 10 years are found to be closely related with the recent intraseasonal temperature change over South Korea. The baroclinic structure of upper-level low and lower-level high system near Korean peninsula provided good condition for vertical cold-air advection, which resulted in minimum temperature on late January in 1973~1982 and early January in 2003~2012 with strengthened low-level northerly flow.
        98.
        2014.07 서비스 종료(열람 제한)
        The change of quality characteristics with storage temperature (room (25°C), low (15°C) and cold (4°C) temperature) and period of unhulled foxtail millet (Setaria italica Beauv. cv. Samdame and Gyeongkwan 1), proso millet (Panicum miliaceum L. cv. Hwanggeum-gijang and Manhongchal) and sorghum (Sorghum bicolor (L.) Moench cv. Hwanggeumchal and Donganme) were evaluated. The 1,000 grain weight, lightness, redness, yellowness and moisture content with storage temperature and period of unhulled foxtail millet, proso millet and sorghum were not showed difference. Germination percent and milling recovery of foxtail millet, proso millet and sorghum decreased with increasing storage temperature and period. Fat acidity of stored foxtail millet, proso millet and sorghum was increased with increasing storage period, and the higher temperature increased more. The results of this study show that the storage of foxtail millet, proso millet and sorghum at the low and cold temperature is better than the room temperature. Especially, in mind of the economics, the storage method is good low temperature than cold temperature.
        99.
        2014.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Recently, cave candidates have been discovered on other planets besides the Earth, such as the Moon and Mars. When we go to other planets, caves could be possible human habitats providing natural protection from cosmic threats. In this study, seven cave candidates have been found on Pavonis Mons and Ascraeus Mons in Tharsis Montes on Mars. The cave candidates were selected using the images of the Context Camera (CTX) on the Mars Reconnaissance Orbiter (MRO). The Context Camera could provide images with the high resolution of 6 meter per pixel. The diameter of the candidates ranges from 50 to 100m. Cushing et al. (2007) have analyzed the temperature change at daytime and nighttime using the Thermal Emission Imaging System (THEMIS) for the sites of potential cave candidates. Similarly, we have examined the temperature change at daytime and at nighttime for seven cave candidates using the method of Cushing et al. (2007). Among those, only one candidate showed a distinct temperature change. However, we cannot verify a cave based on the temperature change only and further study is required for the improvement of this method to identify caves more clearly.
        100.
        2014.05 KCI 등재 서비스 종료(열람 제한)
        Long-term change in sea level along the eastern coast of Korea was illustrated using four tide-gauge station (Pohang, Mukho, Sokcho, Ulleung) data, water temperature and salinity. Seasonal variation in the sea level change was dominant. The sea level change by steric height derived from water temperature and salinity was relatively lower than that measured from the tide-gauge stations. Sea level rising rate per year by steric height increased with latitude. The effect of salinity(water temperature) on the sea level change is greater in winter(in summer).
        1 2 3 4 5