• 제목/요약/키워드: Critical distance

검색결과 623건 처리시간 0.028초

Classification for Types of Damages Caused by Cold Stress at Different Young Spike Development Stages of Barley and Wheat (맥류의 유수발육기 저온장해유형과 피해시기 분류)

  • 구본철;박문웅;김기준;안종국;이춘우;윤의병
    • KOREAN JOURNAL OF CROP SCIENCE
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    • 제48권3호
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    • pp.252-261
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    • 2003
  • Although the young spike of barley (Hordeum vulgare L.) or wheat (Triticum aestivum L.) is known as the most susceptible part to spring cold injury, the risk of cold injury is apt to be ignored in most breeding program due to the importance of early maturity. Based on these aspects, the types and inducing time, temperature conditions for induction and effects of cold injury on growth and yield in this study were investigated under greenhouse and field conditions through three years (1997-1999). In natural condition, low temperature around -2.4∼$-10.2^{\circ}C$ caused the death of plant. Several cold injury types such as partial degeneration of spike, partial discoloration of leaf, spike and awn, discoloration of culm and white spike were observed at low temperature around $-3.1^{\circ}C$. Low temperature around -2.4∼$-8.6^{\circ}C$ and 1.3-$7.6^{\circ}C$ caused degeneration and sterility of spike, respectively. Most materials were prepared to the spikelet foundation stage, spikelet differentiation stage, development stage of flower organ, booting stage and heading stage, which were known having risk for cold injury in field condition. Although most of the controlled stages were sensitive to the induced low temperature, booting stage was the most sensitive stage for cold injury. All of growth stages which were treated-heading stage, booting stage, development stage of flower organ, spikelet differentiation stage, spikelet foundation stage-were responded to low temperature treatment but the symptoms revealed were very specific according to the growth stages. Ears of plant in heading stage were discolored to white. Ears of plant in booting stage were degenerated in all or part of one. Plants in spikelet differentiation stage were sterile in all or part of one. When tried to detect the specific differences between normal and cold injured plants in appearance, spike length, distance between spike and flag leaf and the first internode length could be the critical points for occurrence of spike death caused by cold injury. In barley, the elongation of spike was stopped on 3.2cm after occurrence of spike degeneration, 4.7cm after occurrence of partial degeneration of spike, 5.0cm after occurrence of white spike. In wheat, it was stopped on 1.6cm after occurrence of stem death, 3.3cm after occurrence of spike degeneration, 8.3cm after occurrence of partial degeneration of spike, 8.1cm after occurrence of white spike, 7.5cm after partial discoloration of leaf and 9.3cm after partial discoloration of spike. The obtained results from low temperature treatment induced in growth chamber were similar to the field experiment, Beacuse the death of spikes was more when low temperature was treated two times than one times, the temperature should be upgrade to -3$^{\circ}C$ in order to get the same condition with field test.

Analysis on the Effect of Lessons with the GIS Application in Teaching and Learning of Geography of Elementary School (초등학교 지리학습에 있어서 GIS 활용수업의 효과분석)

  • Park, Soon-Ho;Jung, Eun-Ju
    • Journal of the Korean association of regional geographers
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    • 제14권3호
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    • pp.269-278
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    • 2008
  • This research analyzed the effect of lessons with the GIS application as an alternative scheme of teaching and learning of geography in elementary school. Two classes in the third grade at Y elementary school in Andong were selected to conduct lessons on 'The Landscape of My Hometown' from March 6 through June 30, 2006. In the experimental class, the lessons were conducted with the GIS application; while, in a comparative class, the lessons were carried with usual teaching and learning method. To find out the effect of lessons with the GIS application, differences of spatial cognition of students were figured out between groups, and before and after lessons. The difference between the spatial concept development stages and materials on the textbook discouraged students to pursue their learning as well as made them hard to achieve the goals of lessons. The GIS application had been suggested as an alternative teaching and learning method to overcome the difference; however, it has been hard to find any empirical research to verify the effect of the lessons with GIS application in elementary school. The ability of spatial cognition of the third graders at an elementary school was very low as the result of that curricula in the first and second grades dealt with sketch maps as teaching and learning media. The map learning of third grader on the transitional stage would play the critical role to develop the spatial cognition ability in the future. The field study contributing to developing spatial cognition ability would not be conducted at school. It was required to have the alternative learning schemes such as lessons with GIS application. The lessons with GIS application verified effect of GIS application as the alternative method. The GIS application helped students to recognize landmarks, directions and distance effectively as well as reduced the spatial cognition difference among individuals and/or groups.

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High Dose Rate Interstitial Brachytherapy in Soft Tissue Sarcomas : Technical Aspect (연부조직종양에서 고선량율 조직내 방사선치료: 기술적 측면에서의 고찰)

  • Chun Mison;Kang Seunghee;Kim Byoung-Suck;Oh Young-Taek
    • Radiation Oncology Journal
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    • 제17권1호
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    • pp.43-51
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    • 1999
  • Purpose : To discuss the technical aspect of interstitial brachytherapy including method of implant, insertion time of radioactive source, total radiation dose, and complication, we reviewed patients who had diagnoses of soft tissue sarcoma and were treated by conservative surgery, interstitial implant and external beam radiation therapy Materials and Methods : Between May 1995 and Dec. 1997, ten patients with primary or recurrent soft tissue sarcoma underwent surgical resection (wide margin excision) and received radiotherapy including interstitial brachytherapy. Catheters were placed with regular intervals of 1 ~l.5 cm immediately after tumor removal and covering the critical structures, such as neurovascular bundle or bone, with gelform, muscle, or tissue expander in the cases where the tumors were close to those structures. Brachytherapy consisted of high dose rate, iridium-192 implant which delivered 12~15 Gy to 1 cm distance from the center of source axis with 2~2.5 Gy/fraction, twice a day, starting on 6th day after the surgery, Within one month after the surgery, total dose of 50~55 Gy was delivered to the tumor bed with wide margin by the external beam radiotherapy. Results : All patients completed planned interstitial brachytherapy without acute side effects directly related with catheter implantation such as infection or bleeding. With median follow up duration of 25 months (range 12~41 months), no local recurrences were observed. And there was no severe form of chronic complication (RTOGIEORTC grade 3 or 4). Conclusion : The high dose rate interstitial brachytherapy is easy and safe way to minimize the radiation dose delivered to the adjacent normal tissue and to decrease radiation induced chronic morbidity such as fibrosis by reducing the total dose of external radiotherapy in the management of soft tissue sarcoma with conservative surgery.

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Estimating genetic diversity and population structure of 22 chicken breeds in Asia using microsatellite markers

  • Roh, Hee-Jong;Kim, Seung-Chang;Cho, Chang-Yeon;Lee, Jinwook;Jeon, Dayeon;Kim, Dong-kyo;Kim, Kwan-Woo;Afrin, Fahmida;Ko, Yeoung-Gyu;Lee, Jun-Heon;Batsaikhan, Solongo;Susanti, Triana;Hegay, Sergey;Kongvongxay, Siton;Gorkhali, Neena Amatya;Thi, Lan Anh Nguyen;Thao, Trinh Thi Thu;Manikku, Lakmalie
    • Asian-Australasian Journal of Animal Sciences
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    • 제33권12호
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    • pp.1896-1904
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    • 2020
  • Objective: Estimating the genetic diversity and structures, both within and among chicken breeds, is critical for the identification and conservation of valuable genetic resources. In chickens, microsatellite (MS) marker polymorphisms have previously been widely used to evaluate these distinctions. Our objective was to analyze the genetic diversity and relationships among 22 chicken breeds in Asia based on allelic frequencies. Methods: We used 469 genomic DNA samples from 22 chicken breeds from eight Asian countries (South Korea, KNG, KNB, KNR, KNW, KNY, KNO; Laos, LYO, LCH, LBB, LOU; Indonesia, INK, INS, ING; Vietnam, VTN, VNH; Mongolia, MGN; Kyrgyzstan, KGPS; Nepal, NPS; Sri Lanka, SBC) and three imported breeds (RIR, Rhode Island Red; WLG, White Leghorn; CON, Cornish). Their genetic diversity and phylogenetic relationships were analyzed using 20 MS markers. Results: In total, 193 alleles were observed across all 20 MS markers, and the number of alleles ranged from 3 (MCW0103) to 20 (LEI0192) with a mean of 9.7 overall. The NPS breed had the highest expected heterozygosity (Hexp, 0.718±0.027) and polymorphism information content (PIC, 0.663±0.030). Additionally, the observed heterozygosity (Hobs) was highest in LCH (0.690±0.039), whereas WLG showed the lowest Hexp (0.372±0.055), Hobs (0.384±0.019), and PIC (0.325±0.049). Nei's DA genetic distance was the closest between VTN and VNH (0.086), and farthest between KNG and MGN (0.503). Principal coordinate analysis showed similar results to the phylogenetic analysis, and three axes explained 56.2% of the variance (axis 1, 19.17%; 2, 18.92%; 3, 18.11%). STRUCTURE analysis revealed that the 22 chicken breeds should be divided into 20 clusters, based on the highest ΔK value (46.92). Conclusion: This study provides a basis for future genetic variation studies and the development of conservation strategies for 22 chicken breeds in Asia.

Induced Prism by the Categories of Spectacle Frames (안경테 종류에 따른 유발프리즘)

  • Park, Woo-Jung;Kim, Soo Woon;Hwang, Hae-Young;Yu, Dong-Sik;Son, Jeong-Sik
    • Journal of Korean Ophthalmic Optics Society
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    • 제17권3호
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    • pp.311-319
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    • 2012
  • Purpose: One of the critical aspects on dispensing glasses is to match the center of pupils to the optical center of lenses as the mismatched glasses are able to induce uncomfortable effects called prism which has been known to induce phoria, a main cause for asthenopia in many cases. Therefore, we investigated the induced prism occurred by mismatching centers between the center of pupils and the optical center of lenses. Methods: In this study, total 103 subjects were examined whether the center of pupils and the optical center of lenses are matched in horizontal and vertical directions, and then, the data was categorized into 4 groups based on the structural components of glasses. Total amount of prism was compared to show the effect of the glasses frame on the prism induction, and the value of measured prism was compared with the German RAL-RG 915 regulations. Results: The results in respect to the horizontal component showed that the induced prism was not found in 10.7% of total subjects. 73.8% of total subjects were influenced by induced prism, the range of prism was in a tolerance level. However, the 15.5% of total subjects seemed to be influenced by prism which is out of the criterion of tolerance. In case of vertical component, 23.3% of total subjects showed no effects of prism while early adopting glasses, 54.4% of total subjects showed a little prism effect within the criterion of tolerance, and 22.3% of total subjects showed the prism effect out of the tolerance range. This data indicates that group A and B that are less likely adjustable by fitting induce more prism than group C and D in horizontal and vertical components. Conclusions: In higher refractive error condition, it was found that aligning the optical center of lenses with the center of pupils by pre-fitting of glasses frame minimized prism induction in horizontal and vertical components, which ameliorates ocular fatigue. Therefore, appropriate optometric dispensing through fitting by opticians and precise design about monocular PD and monocular Oh are necessary to improve visual perception.

A Geochemical Indicator in Exploration for the Kalaymyo Chromitite Deposit, Myanmar (미얀마 깔레이미요 크롬철석광상 탐사의 지구화학적 인자)

  • Park, Jung-Woo;Park, Gyuseung;Heo, Chul-Ho;Kim, Jihyuk
    • Economic and Environmental Geology
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    • 제50권6호
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    • pp.423-433
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    • 2017
  • Korea Institute of Geoscience and Mineral Resources and Department of Geological Survey and Mineral Exploration in Myanmar have explored the Kalaymyo chromitite deposit, Myanmar since 2013. It is now necessary to find a geochemical indicator for efficient mineral exploration in the future and building a 3D geological model for this ore deposit. Mantle podiform chromitite is a major type of Cr ore in this region, which is considered to be formed by mantle-melt interaction beneath the mantle-crust boundary of oceanic lithosphere. In this study we measured major element composition of spinels in harzburgite, dunite and chromitite, and examined the hypothesis that spinel Cr#(molar Cr/(Cr+Al)${\times}$100) can be used as a geochemical indicator in exploration for the Kalaymyo chromitite. The results show that there is a clear correlation between spinel Cr# and distribution of chromitite. The spinel Cr# of harzburgite increases with decreasing the distance from the chromitite bodies. The spinel composition is also closely associated with texture and occurrence of spinels. The high Cr# spinels (30-48) are subhedral to euhedral and enclosed by olivine whereas the low Cr# spinels (16-27) are anhedral and commonly associated with pyroxenes. Often the low Cr# spinels show symplectite intergrowths with pyroxenes, indicating their residual nature. These petrological and geochemical results suggest that the high Cr# spinels have resulted from mantle-melt interaction. We suggest that spinel Cr# can be used as a geochemical indicator for Cr ore exploration and as one of critical factors in 3D geological model in the Kalaymyo chromitite deposit.

Study on the Impact of Roadside Forests on Particulate Matter between Road and Public Openspace in front of Building Site - Case of Openspace of Busan City hall in Korea - (도심 도로변 가로녹지가 주변 오픈스페이스의 미세먼지농도에 미치는 영향 연구 - 부산시청 광장을 대상으로 -)

  • Hong, Suk-Hwan;Kang, Rae-Yeol;An, Mi-Yeon;Kim, Ji-Suk;Jung, Eun-Sang
    • Korean Journal of Environment and Ecology
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    • 제32권3호
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    • pp.323-331
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    • 2018
  • This study was conducted to examine the effects of constructing streetside urban forests on particulate matter (PM) content in pedestrian paths and open spaces created between the main streets and buildings in a high-rise, high-density urban area. The study site is a 70m-wide open space between Busan City Hall and Jungang-street in Busan, Korea. The results showed that the density of PM differences between the open space and the adjacent main street were small in regions without linear trees and shrub rows during both the weekdays and weekend. On the other hand, the areas with linear trees and shrub rows were found to have significantly higher concentrations of PM compared to the roadway. In particular, sections with linear trees and shrub rows had higher PM levels both on roads and in adjacent open space, indicating that the composition of linear trees and shrub rows increased the concentration of PM in the off-street open space in areas with wide space between the roadway and building. The impact was more significant in the open space than the roadway. This phenomenon can be explained by the fact that PM generated by vehicles flows through the roadside shrubs by rapid wind flow but does not disperse widely in the pedestrian paths where the wind flow was reduced. In this study, we found that the roadside tree and shrub walls slowed the flow of wind, causing vehicle-emitted PM to accumulate if a wide open space was created between the road and building, resulting in higher concentration of PM in the open space. We confirmed that the distance between the road and building was a critical factor for constructing linear trees and shrub rows to reduce PM generated by vehicle traffic.

Effect of an Offshore Fish Culture System on the Benthic Polychaete Community (외해가두리 양식이 저서다모류군집에 미치는 영향)

  • Jung, Rae-Hong;Yoon, Sang-Pil;Kim, Youn-Jung;Lee, Won-Chan;Hong, Sok Jin;Park, Sung-Eun;Oh, Hyung Taik
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • 제18권4호
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    • pp.195-205
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    • 2013
  • Excessive input of organic matters from fish cage farming has been considered as one of the major factors disturbing benthic ecosystem, especially in semi-enclosed coastal waters. Recently offshore aquaculture in the vicinity of Jeju-do has been introduced to minimize that kind of negative impact. This study was conducted to investigate the ecological impacts of offshore aquaculture on the macrobenthic polychaete communities. A total of ten sampling works were carried out for 28 months, spanning from 10 days after starting giving feed to 3 months after stopping giving feed. During the study period, mean current velocity was quite strong with the range of 50 cm/s to 70 cm/s. TOC of surface sediment was constantly low. Significant changes in polychaete community were detected just three months after starting giving feed, which were the increase of the number of species and density at all stations. Up to 18 months after the start of farming, the amount of feed provided played an important role in the fluctuation of the number of species and density, especially at 0 m and 10 m stations. After reducing the amount of feed provided, dominance of some opportunistic species within 10 m distance from fish cages still lasted to the end of aquaculture. However, opportunistic species disappeared 3 months after the end of farming, which indicated the sign of recovery from the disturbance. From these results, the amount of food input and the period of cultivation were critical factors disturbing polychaete community and ensuing changes in this offshore and oligotrophic waters as well. In addition, study on the changes of polychaete community structure before and after fish farming showed more detailed changes in benthic ecological state than geochemical approach did.

A Study on the Place-Cognition Characteristics of Historic Cultural Streets in Deoksugung Doldam-gil (덕수궁 돌담길의 역사문화가로 장소 인식 특성에 관한 연구)

  • Yang, Yoo-sun;Son, Yong-hoon
    • Journal of the Korean Institute of Landscape Architecture
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    • 제47권3호
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    • pp.60-70
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    • 2019
  • Today, Deoksugung Doldam-gil, which is a well-known area in Seoul, has become a mixed place as many places reaching a critical age have been converted into parks. However, the previous research on the Deoksugung Doldam-gil was deficient in that the user, an essential variable, was not considered when assessing the place. Based on that, this study aims to analyze and interpret the perception of the places in Deoksugung Doldam-gil and to analyze factors to further enrich the place to visitors. According to the research, the representative idea of Deoksugung Doldam-gil is "the distance you want to go" and that has influencing factors, such as vehicle restrictions and the improvement of the walking environment. The analysis of classifying the variables that make up the perception of the place, physical environments, activities and meanings showed high awareness in, "streets of green (3.95)" and "stone walls of curves (3.88)." In the category of activities, "walking activities in the inner city (4.01)" and "love and romance (3.57)" were high. These results seem to reflect the spatial characteristics of the streets and the familiar image of the place were important. Five factors were extracted from the factor analysis to provide a more detailed understanding of the place perception, the correlation between each factor, and the place atmosphere of Deoksugung Doldam-gil. These factors confirmed a high correlation between 'green landscape' and 'historicity.' This can be attributed to the fact that the analysis reflects vital space, visual experience, and free walking conditions to be important, and these variables are present in urban parks. It also indicates the long-accumulated image and behavior near the site of Deoksugung Palace, including the historical and cultural heritage. It was confirmed that the factors related to the cognitive perception of Deoksugung Doldam-gil and the formation of the atmosphere of the place were strongly recognized. It found that there was a need to reflect the value and importance of 'green' in the future as culture or in the use of preservation and management related to heritage. This study presented a direction to be noted from the perspective of a user's place awareness, but considered only a fraction of the variables that affect the multidimensional sense of place and location recognition, and thus must be supplemented in the future.

The Aesthetics of Conviction in Novel and Film Mephisto (소설과 영화 속 '메피스토'의 사상성 미학)

  • Shin, Sa-Bin
    • Journal of Popular Narrative
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    • 제25권1호
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    • pp.217-247
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    • 2019
  • This research paper intends to examine the intertextuality of Klaus Mann's novel Mephisto (1936) and István Szabó's film Mephisto (1981) and how the derivative contents (i.e., film) accepted and improved the schematic aesthetics of conviction in original contents (i.e., novel). In general, the aesthetics of conviction is applied to criticize the state socialism of the artists of the Third Reich or the ideology of the artists of East Germany from a biased ethical perspective. Mephisto is also based on the aesthetics of conviction. Thus, it would be meaningful to examine the characteristic similarity and difference between Klaus Mann's real antagonist (i.e., Gustaf Gründgens) and fictional antagonist (i.e., Hendrik Höfgen) from a historical critical perspective. In this process, an aesthetic distance between the real and fictional antagonists would be secured through the internal criticism in terms of intertextuality. In this respect, the film aesthetics of István Szabó are deemed to overcome the schematic limit of the original novel. The conviction in both the novel and film of Mephisto pertains to the belief and stance of a person who compromised with the state socialism of Nazi Germany, i.e., succumbed to the irresistible history. Klaus Mann denounced Mephisto's character Höfgen (i.e., Gründgens in reality) as an "Mephisto with evil spirits" from the perspective of exile literature. For such denunciation, Klaus Mann used various means such as satire, caricature, sarcasm, parody and irony. However, his novel is devoid of introspection and "utopianism", and thus could be considered to allow personal rights to be disregarded by the freedom of art. On the contrary, István Szabó employed the two different types of evil (evil of Mephisto and evil of Faust) from a dualistic perspective (instead of a dichotomous perspective of good and evil) by expressing the character of Höfgen like both Mephisto and Hamlet (i.e., "Faust with both good and evil spirits). However, Szabó did not present the mixed character of "Mephisto and Hamlet (Faust)" only as an object of pity. Rather, Szabó called for social responsibility by showing a much more tragic end. As such, the novel Mephisto is more like the biography of an individual, and the film Mephisto is more like the biography of a generation. The aesthetics of conviction of Mephisto appears to overcome biased historical and textual perspectives through the irony of intertextuality between the novel and the film. Even if history is an irresistible "fate" to an individual, human dignity cannot be denied because it is the "value of life". The issue of conviction is not only limited to the times of Nazi Germany. It can also be raised with the ideology of the modern and contemporary history of Korea. History is so deeply rooted that it should not be criticized merely from a dichotomous perspective. When it comes to the relationship between history and individual life, a neutral point of view is required. Hopefully, this research paper will provide readers with a significant opportunity for finding out their "inner Mephisto" and "inner Hamlet."