• Title/Summary/Keyword: nature of technology

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A Comparison Study of Alkalinity and Total Carbon Measurements in $CO_2$-rich Water (탄산수의 알칼리도 및 총 탄소 측정방법 비교 연구)

  • Jo, Min-Ki;Chae, Gi-Tak;Koh, Dong-Chan;Yu, Yong-Jae;Choi, Byoung-Young
    • Journal of Soil and Groundwater Environment
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    • v.14 no.3
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    • pp.1-13
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    • 2009
  • Alkalinity and total carbon contents were measured by acid neutralizing titration (ANT), back titration (BT), gravitational weighing (GW), non-dispersive infrared-total carbon (NDIR-TC) methods for assessing precision and accuracy of alkalinity and total carbon concentration in $CO_2$-rich water. Artificial $CO_2$-rich water(ACW: pH 6.3, alkalinity 68.8 meq/L, $HCO_3^-$ 2,235 mg/L) was used for comparing the measurements. When alkalinity measured in 0 hr, percent errors of all measurement were 0~12% and coefficient of variation were less than 4%. As the result of post-hoc analysis after repeated measure analysis of variance (RM-AMOVA), the differences between the pair of methods were not significant (within confidence level of 95%), which indicates that the alkalinity measured by any method could be accurate and precise when it measured just in time of sampling. In addition, alkalinity measured by ANT and NDIR-TC were not change after 24 and 48 hours open to atmosphere, which can be explained by conservative nature of alkalinity although $CO_2$ degas from ACW. On the other hand, alkalinity measured by BT and GW increased after 24 and 48 hours open to atmosphere, which was caused by relatively high concentration of measured total carbon and increasing pH. The comparison between geochemical modeling of $CO_2$ degassing and observed data showed that pH of observed ACW was higher than calculated pH. This can be happen when degassed $CO_2$ does not come out from the solution and/or exist in solution as $CO_{2(g)}$ bubble. In that case, $CO_{2(g)}$ bubble doesn't affect the pH and alkalinity. Thus alkalinity measured by ANT and NDIR-TC could not detect the $CO_2$ bubble although measured alkalinity was similar to the calculated alkalinity. Moreover, total carbon measured by ANT and NDIR-TC could be underestimated. Consequently, it is necessary to compare the alkalinity and total carbon data from various kind of methods and interpret very carefully. This study provide technical information of measurement of dissolve $CO_2$ from $CO_2$-rich water which could be natural analogue of geologic sequestration of $CO_2$.

Construction of Tomato yellow leaf curl virus Clones for Resistance Assessment in Tomato Plants (토마토 작물의 TYLCV 저항성 평가에 이용할 수 있는 감염성 클론 개발)

  • Choi, Seung Kook;Choi, Hak Soon;Yang, Eun Young;Cho, In Sook;Cho, Jeom Deog;Chung, Bong Nam
    • Horticultural Science & Technology
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    • v.31 no.2
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    • pp.246-254
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    • 2013
  • Five isolates of Tomato yellow leaf curl virus (TYLCV) collected from various regions of Korea were amplified using PCR and determined the sequences of full-length genome, respectively. The PCR-amplified DNA of each TYLCV isolate was introduced into a binary vector to construct infectious clone containing 1.9 copies of the corresponding viral genome. Various cultivars and breeding lines of tomato were inoculated with Agrobacterium tumefaciens harboring infectious clone of each TYLCV isolate to assess resistance against TYLCV. Susceptible cultivar 'Super-sunread' revealed typical yellowing and narrowing of the upper leaves. In contrast, breeding linesTY12, GC9, GC171, and GC173, which contained the TY-1 and/or TY-3 genes that confer resistance against TYLCV in nature, were completely symptomless, suggesting that the lines were resistant to challenging TYLCV isolates. Symptoms of TYLCV in susceptible tomato cultivars are significantly different from those of TYLCV in the resistant tomato cultivars at 30 days after agroinfiltration. Although genomic DNAs of TYLCV were detected from the breeding lines TY12, GC9, GC171, and GC173 using real-time PCR analysis with specific primers, levels of TYLCV DNA accumulation in the resistant breeding lines were much lower than those of TYLCV DNA accumulation in susceptible tomato cultivars. Similar symptom severity and levels of TYLCV DNA accumulation were observed from TYLCV infections mediated by Bemisia tabaci in the resistant and susceptible tomato cultivars. Concentration of agrobacterium did not affect the response of tomato cultivars against TYLCV inoculation. Taken together, these results suggest that TYLCV inoculation via agroinfiltration is as effective as inoculation through Bemisia tabaci and is useful for breeding programs of TYLCV-resistant tomato.

Landscape Gardening Culture in Late Joseon Dynasty Depicted in 'Ahoi-do' Paintings (아회도(雅會圖)에 나타난 조선후기 원림문화)

  • Lim, Eui-Je;So, Hyun-Su
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.32 no.3
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    • pp.46-57
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    • 2014
  • This study contemplated the gardening culture from the pictures, which the scholars of late Joseon Dynasty, the aspects of garden landscapes and garden use behaviors are drawn as follows. 1. The yard by the detached house for men and guest in front of the premises(Sarang Madang) and backyard were the major places for Ahoi(social gatherings of the scholars). The mansions had interests in the management of the outer garden beyond the house wall with building structures like the pavilions on the high walls and side gates. This management and the selection of location anticipating in advance of the management are noteworthy. 2. Only house gardens had plant pots with flowers and the small flower bed(Hwa-O) at Sarang Madang occasionally had plant pots without flowers and oddly shaped stone pots and equipped pine branch eaves and traditional awnings made of plant material like a trellis. 3. The oddly shaped stones were significant landscape elements in the gardens of houses and villas. Some of them were depicted as the Taihu stone and this draws attention to the question of whether the Taihu stone was actually used in the garden of late Joseon Dynasty. 4. The gardens in villas accommodated the borrowed scenery with various materials like wooden fences, bamboo or reed fences, mud walls. They also had the artificial gardens with some odd shaped stones, old pines, bamboos, Japanese apricots, willows, paulownia trees, lotuses and plantains in the secured Madangs. 5. Gyeong Hwa Sa Jog(The scholars of the ruling class adapted to the 18th century's new historical aspect) of late Joseon Dynasty built the villas at the beautiful scenery closed to the their houses. 6. The Gardens around pavilions were located high closed to the mountain streams with nature like beautiful forests, oddly formed rocks, precipitous cliffs and viewing stones. The back side of the pavilion was enclosed by bamboo forests and the front had pines, ginkgoes and willows as shade trees. 7. The beautiful scenery which was preferred as the place for Ahoi was basically with fantastic peaks and precipitous cliffs which forms the distant view harmonized with a waterfall. Broad and flat rocks at the summit of a mountain which commands a bird's-eye view or on a mountain streamside with pine forest, willows and plum trees were chosen as the optimal places for Ahoi. 8. Pine trees were presumed to be more preferable than other species in the garden, especially an single planted old pine tree accented symbolism. 9. Portable tea braziers for boiling tea were adopted in all four types of the gardens. 10. The gardens mixed with auspicious landscape elements were the places of the arts for an unworldliness Ahoi through GeumGiSeoHwa(enjoying strings, go, writing and painting) and boiling tea.

Exploring the Use of Traditional Science Knowledge by 'Being a Commentator on Korean Traditional Science Culture' Activities (우리 과학 문화 해설사 되어보기 활동을 통한 전통 과학 지식의 교육적 활용 방안 탐색)

  • Lee, Jihye;Shin, Donghee
    • Journal of The Korean Association For Science Education
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    • v.37 no.1
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    • pp.193-214
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    • 2017
  • This study was carried out to identify the reality of students' understanding of Korean traditional scientific knowledge (TSK), the educational contexts influenced their understanding of TSK, and their sense of value of TSK, through the science activity 'Being a commentator on Korean traditional scientific culture' as a way of finding direction to apply TSK to science education while maintaining the inherent meaning of our traditional science. Seventh grade students have discovered TSK contents in Changdeok Palace, prepared their own scripts for seven months, and finally, explained to fifth to sixth grade students. The video recordings of all lessons, scripts of explanation, reports of field activities, and individual interviews were all analyzed. Students understood TSK in four viewpoints: the traditional view of nature, the traditional science and technology, the traditional life using science, and the natural science contents. During their activities, communication with peers or elders both in classroom and in Changdeok Palace, the interaction with place, and the sense of responsibility as a commentator helped students understand the scientific aspects of TSK, form contextual and sensible scientific knowledge, and apprehend various scientific explanations of contents. Depending on their internalization of experiences, the students' experiences produced three types of interpretation: delivery, persuasion, and understanding. Students formed their TSK sense of value as scientific characteristics, the need of new perspective about science, the need to protect and maintain TSK as our culture. The results of this study show that TSK can provide integrated and actual contextual education in science education and can be used to understand the cultural diversity of scientific and scientific methods and the characteristics of oriental scientific thinking. In addition, the simultaneous approach of TSK and school science to traditional culture can contribute to ideal concept formation and subjective attitude toward our traditional culture.

Distribution and Behavior of $^{137}Cs$ According to topography and nature of the soil around Yeong-Gwang NPPs, (영광원자력발전소 주변의 지형 및 지질에 따른 $^{137}Cs$ 분포 및 거동에 관한 연구)

  • Han Sang-Jun;Lee Goung-Jin;Kim Hee-Geun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.2 no.4
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    • pp.271-278
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    • 2004
  • This paper shows our experiment is performed to understand the exposure tendency of $^{137}Cs$ according to the height of area and also, to supplement it by considering chemical characters of $^{137}Cs$ exposed to the soil. The samples we use for this experiment are from the general flat area of Yeonggwang county where it has NPPs, the high places of Keumjung & Bulgap mountains, and Naejan mountain where it is quite far from the NPPs. The data from this experiment show that the exposure of $^{137}Cs$ is not harmful since its range is around 252 Bq/kg-dry in most of sampled soils such as from the general flat area, the high place of Keumjung mountain where is 2 km away from the NPPs, the other high place of Bulgap mountain where is about 20 km away from the NPPs, and Naejan mountain where it is far from the NPPs. Not like the general flat area, however, the data show that the higher the area is the more $^{137}Cs$ is exposed. That is, at the top of mountains, the more $^{137}Cs$ is exposed compared to at the bottom area. It is almost $2{\~}6$ times more than the general flat area of Yeonggwang county where it has NPPs. The data also show that the spread of $^{137}Cs$ is deeply related to the geographical(the height of area, rainfall, etc..) factors and chemical factors of soils. As the geographical factors, there are far more chances to be exposed of $^{137}Cs$ at the high area of mountains through the air compared to at lower area and therefore, we can get more high-leveled readings of $^{137}Cs$ at the high area while it is low-leveled ones at the general flat area even if both of them have the same soil conditions. Regarding the chemical factors of soil, it is clarified that the CEC is the key factor. The CEC means the capability of sticking $^{137}Cs$ accumulated into the soil. Hence, the more CEC it has the more high-leveled readings of $^{137}Cs$ we get under the same geographical condition.

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Competitive Adsorption Characteristics of Rapid Cooling Slag in Single- and Multi-Metal Solutions (단일 및 복합중금속용액에서 제강급랭슬래그의 경쟁흡착특성)

  • Park, Jong-Hwan;Kim, Hong-Chul;Kim, Seong-Heon;Lee, Seong-Tae;Kang, Byung-Hwa;Kang, Se-Won;Seo, Dong-Cheol
    • Korean Journal of Environmental Agriculture
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    • v.35 no.1
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    • pp.24-31
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    • 2016
  • BACKGROUND: Heavy metal adsorption not only depends on rapid cooling slag(RCS) characteristics but also on the nature of the metals involved and on their competitive behavior for RCS adsorption sites. The goal of this study was to investigate the competitive absorption characteristics of Cu, Cd and Zn in single- and multi-metal forms by RCS.METHODS AND RESULTS: Both single- and multi-metal adsorption experiments were conducted to determine the adsorption characteristics of RCS for the heavy metals. Adsorption behaviors of the heavy metals by RCS were evaluated using both the Freundlich and Langmuir adsorption isotherm equations. The maximum adsorption capacities of metals by RCS were in the order of Cu(16.6 mg/g) > Cd(8.1 mg/g) > Zn(6.2 mg/g) in the single-metal adsorption isotherm and Cu(14.5 mg/g) >> Zn(1.3 mg/g) > Cd(0.6 mg/g) in the multi-metal adsorption isotherm. Based on data obtained from Freundlich and Langmuir adsorption models and three-dimensional simulation, multi-metal adsorption behaviors differed from single- metal adsorption due to competition. Cadmium and Zn were easily exchanged and substituted by Cu during multi-metal adsorption.CONCLUSION: Results from adsorption experiments indicate that competitive adsorption among metals increases the mobility of these metals.

The Characteristics of Soil Oribatid Mite(Acari: Oribatida) Communities as to Differences of Habitat Environment in Mt. Jumbong, Nature Reserve Area in Korea (점봉산 천연보호림에서 서식환경 차이에 따른 토양날개응애 군집특성)

  • Kang, Bang-Hun;Lee, Joon-Ho;Choi, Seong-Sik
    • Korean Journal of Environment and Ecology
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    • v.21 no.6
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    • pp.536-543
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    • 2007
  • This research was conducted every month from June 1994 until August 1996 with the aim to understand the ecosystem structure through the analysis of oribatid mite community structure in soil subsequent to environmental difference of its habitats located at northward & southward slopes adjacent to each other at an altitude of 1,000 meters of Mt.Jumbong, which is a natural reserved forest, remaining intact. There appeared a significant difference [t-test, p<0.06] in comparison of the number of the species and individuals of Oribatid mite species which were collected and identified at two survey areas. The mean density and the number of the species collected and identified at the northward slopes, and southward slopes were $99.2{\pm}17.6,\;234.2{\pm}62.6$ and $24.7{\pm}3.0,\;40.8{\pm}5.8$, respectively. Species diversity index(H') was higher at the southward slopes($3.09{\pm}0.11$) than at the northward slopes($2.71{\pm}0.13$). The population size of Oribatid mite species was found by the percentage of each species density as against the whole density and classified into dominant species, influent species, and recessive species according to the percentage; as a result, O. nova and Suctobelbella naginata was found to be a dominant species at both survey slopes while Trichogalumna nipponica was found to be a dominant species, at southward but it wasn't collected at the northward slopes at all. The feeding habit of the dominant species at two survey slopes was found to be microphytophagous- eating soil microbe. There appeared a conspicuous difference in compositions of the number of the species, individuals and dominant species at the southward/northward slopes adjoining each other at an attitude of 1,000 meters and less similarity between the two survey slopes. Conclusively, It was found that the heterogeneity of microhabitat has a great effect on Oribatid mite's community characteristics.

A Study on the Application of RTLS Technology for the Automation of Spray-Applied Fire Resistive Covering Work (뿜칠내화피복 작업 자동화시스템을 위한 RTLS 기술 적용에 관한 연구)

  • Kim, Kyoon-Tai
    • Journal of the Korea Institute of Building Construction
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    • v.9 no.5
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    • pp.79-86
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    • 2009
  • In a steel structure, spray-applied fire resistive materials are crucial in preventing structural strength from being weakened in the event of a fire. The quality control of such materials, however, is difficult for manual workers, who can frequently be in short supply. These skilled workers are also very likely to be exposed to environmental hazards. Problems with construction work such as this, which are specifically the difficulty of achieving quality control and the dangerous nature of the work itself, can be solved to some degree by the introduction of automated equipment. It is, however, very difficult to automate the work process, from operation to the selection of a location for the equipment, as the environment of a construction site has not yet been structured to accommodate automation. This is a fundamental study on the possibility of the automation of spray-applied fire resistive coating work. In this study, the linkability of the cutting-edge RTLS to an automation system is reviewed, and a scenario for the automation of spray-applied fire resistive coating work and system composition is presented. The system suggested in this study is still in a conceptual stage, and as such, there are many restrictions still to be resolved. Despite this fact, automation is expected to have good effectiveness in terms of preventing fire from spreading by maintaining a certain level of strength at a high temperature when a fire occurs, as it maintains the thickness of the fire-resistive coating at a specified level, and secures the integrity of the coating with the steel structure, thereby enhancing the fire-resistive performance. It also expected that if future research is conducted in this area in relation to a cutting-edge monitoring TRS, such as the ubiquitous sensor network (USN) and/or building information model (BIM), it will contribute to raising the level of construction automation in Korea, reducing costs through the systematic and efficient management of construction resources, shortening construction periods, and implementing more precise construction

Technology for Improving the Uniformity of the Environment in the Oyster Mushroom Cultivation House by using Multi-layered Shelves (느타리버섯 균상재배사의 환경균일성 향상을 위한 기술 개발)

  • Lee, Sunghyoun;Yu, Byeongkee;Kim, Hyuckjoo;Yun, Namkyu;Jung, Jongcheon
    • Journal of Bio-Environment Control
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    • v.24 no.2
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    • pp.128-133
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    • 2015
  • Mushrooms can grow in nature when adequate temperature and humidity are maintained, but such condition can be satisfied for only a short period of time on an annual continuum. Therefore, it can be deemed that a majority of the distributed mushrooms in the current market are produced in an artificially manipulated environment. This study was conducted to resolve the problem of the Oyster mushroom cultivation house's internal temperature and humidity imbalance, where the Oyster mushrooms are cultivated in a multi-layered shelves. The air circulation fans were installed to improve the air uniformity of the Oyster mushroom cultivation house by using multi-layered shelves. During the experiment, the ambient temperature and the ambient relative humidity ranged from $5.2^{\circ}C$ to $20.4^{\circ}C$ and 40% to 100% respectively. Due to the change of the outdoor temperature, the internal temperature of the Oyster mushroom cultivation house also changed, ranging from $13.3^{\circ}C$ to $18.4^{\circ}C$, but the temperature gap between the different internal location of the facility during the conforming recorded time only ranged from $0.2^{\circ}C$ to $1.3^{\circ}C$, being significantly stable. The internal relative humidity, ranging from 82% to 96%, also changed due to the change of the outdoor temperature. Nevertheless, the relative humidity gap between the different internal location during the conforming recorded time only ranged from 2% to 7%. Furthermore, the research staff were able to maintain the concentration of $CO_2$ from 575ppm to 731ppm(below 1,000ppm was the goal) indicating the possibility of an even management of the internal environment by installing the air circulation fan.

Development of a water quality prediction model for mineral springs in the metropolitan area using machine learning (머신러닝을 활용한 수도권 약수터 수질 예측 모델 개발)

  • Yeong-Woo Lim;Ji-Yeon Eom;Kee-Young Kwahk
    • Journal of Intelligence and Information Systems
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    • v.29 no.1
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    • pp.307-325
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    • 2023
  • Due to the prolonged COVID-19 pandemic, the frequency of people who are tired of living indoors visiting nearby mountains and national parks to relieve depression and lethargy has exploded. There is a place where thousands of people who came out of nature stop walking and breathe and rest, that is the mineral spring. Even in mountains or national parks, there are about 600 mineral springs that can be found occasionally in neighboring parks or trails in the metropolitan area. However, due to irregular and manual water quality tests, people drink mineral water without knowing the test results in real time. Therefore, in this study, we intend to develop a model that can predict the quality of the spring water in real time by exploring the factors affecting the quality of the spring water and collecting data scattered in various places. After limiting the regions to Seoul and Gyeonggi-do due to the limitations of data collection, we obtained data on water quality tests from 2015 to 2020 for about 300 mineral springs in 18 cities where data management is well performed. A total of 10 factors were finally selected after two rounds of review among various factors that are considered to affect the suitability of the mineral spring water quality. Using AutoML, an automated machine learning technology that has recently been attracting attention, we derived the top 5 models based on prediction performance among about 20 machine learning methods. Among them, the catboost model has the highest performance with a prediction classification accuracy of 75.26%. In addition, as a result of examining the absolute influence of the variables used in the analysis through the SHAP method on the prediction, the most important factor was whether or not a water quality test was judged nonconforming in the previous water quality test. It was confirmed that the temperature on the day of the inspection and the altitude of the mineral spring had an influence on whether the water quality was unsuitable.