• 한국관개배수논문집
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• 제17권2호
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• pp.17-27
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• 2010

In order to manage the water quality in reservoir, it is necessary to understand the temporal and spatial variation of reservoirs and to classify the reservoirs. In this research, agricultural reservoirs are classified according to physical characteristics (depth, residence time, shape of the reservoir etc) and water quality using multivatriate analysis (PCA and CA). CA (Cluster Analysis) method classify reservoirs into several groups as a similarity of the reservoirs, but it is difficult to indicate a full list to the one table. In case of PCA (Principle Component Analysis) method, it has the advantage for the classification on the reservoirs depending on the water quality similarity and also it is useful to analyze the relationship between related factors through correlation analysis. However PCA is limited to classify into several groups based on the characteristics of the reservoirs and each user should be classified as randomly subjective according to the relative position of the reservoir in the figure. In conclusions, compared to conventional reservoirs classification methods, both CA and PCA methods are considered to be a classification method that describes the nature of the reservoir well, but classification results has a restriction on use, so further research will be needed to complement.

• 한국농림기상학회지
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• 제23권4호
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• pp.316-328
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• 2021

본 연구에서는 간척지의 염분 모니터링을 위한 다중 분광 센서를 개발하기 위해 400~1000 nm 초분광센서를 사용하여 봄 감자의 잎 Na 함량 예측 모델을 구축하고자 하였다. 관개조건은 표준, 한해, 염해(2, 4, 8 dS/m)로, 관수량은 증발량을 기준으로 산정하였다. 영양생장기, 괴경형성기, 괴경비대기에 각각 관개를 시작한 후 1주와 2주 후에 잎의 Na 함량을 측정하였다. 잎의 반사율은 10nm 파장 간격을 기준으로 5 nm에서 10nm, 25nm, 50nm FWHM (full width at half maximum)으로 변환되었다. PLS-VIP를 사용하여 봄 감자 잎의 Na 함량에 따른 염분 피해 수준을 예측하기 위한 10개의 밴드비가 선택되었다. 선택된 10개의 밴드비 중 가중치가 가장 낮은 순서대로 밴드비를 하나씩 제거하면서 MLR모델을 추정하였다. 모델의 성능은 R2, MAPE 뿐만 아니라 밴드비의 수, 다중 분광센서를 작게 만들기 위한 최적의 FWHM 수로 비교하였다. 1, 2주차의 영양생장기, 괴경형성기와 2주차의 괴경비대기에서 봄 감자의 잎 Na 함량을 예측하기 위해서는 25 nm의 FWHM을 사용하는 것이 유리하였다. 선택된 밴드필터는 430/440, 490/500, 500/510, 550/560, 570/580, 590/600, 640/650, 650/660, 670/680, 680/690, 690/700, 700/710, 710/720, 720/730, 730/740 nm로 Red 및 Red-edge 영역에서 15개 밴드비가 선택되었다.

• 한국습지학회지
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• 제9권1호
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• pp.69-78
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• 2007

Constructed wetlands and other aquatic systems have been successfully used for waste and wastewater treatment in either temperate or tropical regions. To treat waste or wastewater in a sustainable manner, the integrated eco-engineering designs are explained in this paper with 2 case studies: (i) a combination of vertical-flow constructed wetland (CW) with plant irrigation systemfor fecal sludge management and (ii) integrated CW units with landscaping at full-scale application for domestic wastewater treatment. The pilot-scale study of fecal sludge management employed 3 vertical-flow CW units, each with a dimension of $5{\times}5{\times}0.65m$ (width ${\times}$ length ${\times}$ media depth) and planted with cattails (Typha augustifolia). At the solid loading rate of 250 kg total solids (TS)/$m^2.yr$ and a 6-day percolate impoundment, the CW system could achieve chemical oxygen demand (COD), TS and total Kjeldahl nitrogen (TKN) removal efficiencies in the range of 80 - 96%. The accumulated sludge layers of about 80 - 90 cm was found at the CW bed surface after operating the CW units for 7 years, but no clogging problem has been observed. The CW percolate was applied to 16 irrigation Sunflower plant (Helianthus annuus) plots, each with a dimension of $4.5{\times}4.5m$ ($width{\times}length$). In the study, the CW percolate were fed to the treatment plots at the application rate of 7.5 mm/day but the percolate was mixed with tap water at different ratio of 20%, 80% and 100%. Based on a 1-year data of 3-crop plantation were experimented, the contents of Zn, Mn and Cu in soil of the experimental plots were found to increase with increasing in CW percolate ratios. The highest plant biomass yield and oil content of 1,000 kg/ha and 35%, respectively, were obtained from the plots fed with 20% or 50% of the CW percolate, whereas no accumulation of heavy metals in the plant tissues (i.e. leaves, stems and flowers) of the sunflower is found. In addition to the pilot-scale and field experiments, a case study of the integrated CW systems for wastewater treatment at Phi Phi Island (a Tsunami-hit area), Krabi province, Thailand is illustrated. The $5,200-m^2$ CW systems on Phi Phi Island are not only for treatment of $400m^3/day$ wastewater from hotels, households or other domestic activities, but also incorporating public consultation in the design processes, resulting in introducing the aesthetic landscaping as well as reusing of the treated effluent for irrigating green areas on the Island.

• Weed & Turfgrass Science
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• 제4권4호
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• pp.405-412
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• 2015

학교 운동장은 체육활동 외에도 학생들과 지역 주민들의 다양한 여가 활동이 이루어지는 중요한 공간이다. 본 연구는 운동장 조성 및 잔디관리 현황 조사를 통하여 천연잔디학교 운동장의 문제점을 파악하고 앞으로 학교 운동장 잔디의 품질향상을 위한 기초자료로 활용하고자 수행되었다. 경기도내에 천연잔디 학교 운동장 40개소를 방문하여 운동장관리 관계자와의 질문 답변과 현장조사 결과 학교당 운동장 면적은 평균 $3,890m^2$, 1인당 운동장 면적은 평균 $12m^2$로 나타났다. 운동장 잔디관리는 학교 관계자에 의한 자체 관리가 조사 대상 학교의 95%로 나타났고, 잔디관리 비용은 조사된 학교의 대부분인 90%가 5백만원 이하의 적은 비용으로 유지 관리되고 있었다. 천연잔디 학교 운동장의 문제점으로는 잔디관리의 어려움과 잔디관리에 소요되는 비용 부담 등으로 나타났다. 운동장 잔디관리의 가장 큰 어려움으로 잡초관리와 관수작업으로 나타났다. 학교 운동장은 조사대상의 97.5%가 한국잔디로 조성되어 있었으며 시비 년2회, 깎기 년6회, 잡초방제 월2회, 관수는 위조발생시 처리하는 수준으로 나타나 많은 학교가 최소관리 수준에서 잔디관리가 이루어지고 있는 것으로 조사되었다. 학교 운동장의 잔디상태는 양호한 곳이 14개소, 개선을 요하는 수준에 있는 학교가 26개소로 관배수시설 확충과 함께 기본적인 잔디관리 수준을 높임과 동시에 잔디보식, 통기, 배토 등과 같은 적극적인 갱신작업을 통하여 운동장 잔디 품질 향상이 필요한 것으로 판단되었다.

• 원예과학기술지
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• 제31권1호
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• pp.38-49
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• 2013

Prohexadione-calcium (Pro-Ca), ethephon and transient water stress were evaluated in a factorial design, as potential inhibitors of early-season shoot growth of high density orchard management of apple (Malus domestica Borkh.) trees. In the experiment, water stress was imposed to one-half of the 7-year-old 'Golden Delicious'/M.9 apple trees in each of 5 blocks, by stopping irrigation for 3 weeks between 35 and 56 days after full bloom (AFB). Within each whole unit, the following Pro-Ca and ethephon treatments were randomly allocated at $2{\times}2$ factorial: a) 0 or 250 $mg{\cdot}L^{-1}$ a.i. Pro-Ca applied at 28 days AFB and b) 0 or 300 $mg{\cdot}L^{-1}$ a.i. ethephon applied twice (35 and 71 days AFB). All trees were hand thinned to king flowers prior to treatments. Vegetative shoot growth was markedly reduced by Pro-Ca, with its effect being obvious within 14 days after application, while ethephon and water stress treatments were less effective. Pro-Ca had no effect on fruit set and yield but slightly increased fruit size. Ethephon substantially reduced the fruit size and yield but had no effect on fruit set. Water stress reduced fruit set, fruit size and yield. With regard to fruit quality, Pro-Ca did not influence fruit shape, flesh firmness and soluble solids contents (SSC) but slightly reduced titratable acidity. Ethephon had no effect on fruit shape but increased firmness, SSC and acidity, while water stress did not influence these fruit quality attributes. Dry weight of dormant spur buds was reduced by both Pro-Ca and water stress, while increased by ethephon. The larger dormant buds led to the larger spur flowers at the tight cluster stage the following spring. Return flowering was promoted only by ethephon, especially on previous season's shoots. There were no significant interactions between Pro-Ca and ethephon or water stress on most variables observed in this study.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.272-272
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• 2022

Water and phosphorus (P) fertilizer are two of the most critical inputs in rice cultivation. Under climate change scenarios and urbanization, irrigation and fertilizer are becoming limiting factors often leading to significant decrease in yield whenever supplied scarcely. It has been shown that the Pup1 QTL confers tolerance to P starvation and improved early-stage root vigor in indica rice grown in the tropics. However, whether the QTL works in japonica rice genetic background grown in temperate regions remains to be elucidated. Here, we have introgressed the Pup1 QTL into three temperate rice varieties MS11, TR22183, and Dasan using marker-assisted backcrossing and next generation sequencing. The selected lines all harbored the full Pup1 QTL with recurrent parent genome recovery rates ranging from 66.5% to 99.8%. Evaluation of the introgression rice lines grown in South Korea under low inputs of P and water revealed early vegetative growth advantage relative to that of the recurrent parents. Under rainfed condition, Pup1 introgression lines had yield advantage ranging from 7.2 to 19.9% and 24 to 26% in P non-supplied soil and P-supplied soil, respectively compared to that of the recurrent parents suggesting that Pup1 confers enhanced yield under low P and water inputs in temperate rice genetic background grown in temperate climate. In terms of early vegetative growth, temperate Pup1 introgression lines showed a similar trend on the extent to which Pup1 promotes yield advantage in temperate rice in comparison with indica control Pup1 introgression line IR64-Pup1.

• 아시안잔디학회지
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• 제20권1호
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• pp.25-31
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• 2006

'Meyer' zoysiagrass(Zoysia iaponica Steud.)는 일반적으로 미국 중부지역에서 골프장 페어 웨이 또는 티에 일반적으로 많이 쓰이는 잔디로 적은 시비와 관수와 함께 좋은 플래이를 제공한다. 하지만 그늘 지역에서의 생육이 저하되어 품질을 떨어뜨린다. 감소되어진 광량은 잔디 잎의 웃자람을 일으키며 밀도가 저하되고 약한 잔디 생육과 함께 답압이나 디보트에 따른 재생을 저하시킨다. 이 실험의 목적은 TE의 처리가 그늘 지역에서의 잔디의 웃자람을 억제하고 품질을 향상 시키는가를 알아보기 위함에 있다. 이 실험에서 두 가지 처리는 차광 조건(0%, 79%, 92% 차광막) 과 TE [0, 48(0.5x), $96g{\cdot}ha^{-1}\;a.i(1x)$]로 적용하였다. 무 차광 처리 시, 0.5x-비율로 TE처리에서 4 주후 무 처리구에 비해 18%의 잔디 예초물의 감소를 보였고 1x-비율의 TE 처리는 $30{\sim}38%$의 예초물 감소를 보였다. 매달 1x-비율의 TE 처리 시 무 차광 처리와 79% 차광에서 zosiagrass의 밀도를 증가 시켰다. 무 처리에 비해 두 TE 비율의 처리가 잔디의 웃자람을 감소시켰으며 1x-비율로 TE 처리 시 79% 차광에서 잔디 품질이 저하되는 것이 지연되었다. 이 실험에서 그늘진 지역에서의 TE 처리가 zoysiagrass 의 웃자람을 줄이고 잔디 품질을 향상 시킨다는 것을 알 수 있었다.

• Journal of Periodontal and Implant Science
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• 제37권4호
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• pp.791-803
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• 2007

The purpose of this study was to evaluate exophytically vertical bone formation in residual ridge of the beagle dog by the concept of guided bone regeneration with a titanium reinforced e-PTFE membrane combined with irradiated cancellous human bone. Twelve male beagle dogs(mean age 1.5 years and mean weight 12kg) were used for this study. The alveolar ridges after extraction of all mandibular premolars were surgically and horizontally removed. At 8 weeks after extractions, full-thickness flap was reflected and cortical bone was removed with round bur and copious irrigation. Rectangular parallelepiped(10mm in length, 5mm in width, and 4mm in height) bended with titanium-reinforced e-PTFE(TR e-PTFE) membrane was placed on the decorticated alveolar ridge, fixed with metal pins and covered with full-thickness flap and assigned as a control group. Test groups ere treated with TR e-PTFE membrane filled with irradiated cancellous human bone. Of twelve beagle dogs, four control dogs and four test dogs without membrane exposure to oral cavity were sacrificed at 8 and 16 weeks respectively. The surgical sites were dissected out, fixed in 4% buffered formaldehyde, dyed using a Villanueva staining technique, and processed for embedding in plastic resin. The cutting and grinding methods were routinely processed for histologic and histomophometric analyis of exophytic bone formation as well as statistical analysis. The results of this study were as follows: 1. Exophytic bone formation in the both of experimental groups was increased respectively after surgery from 23.40% at 8 weeks to 46.26% at 16 weeks in the control groups, from 40.23% at 8 weeks to 47.11% at 16 weeks in the test groups(p<0.05). 2. At 8 weeks after surgery, exophytic bone formation was made 40.23% in the test groups and 33.40% in the control groups. Exophytic bone formation was significantly made in the test group more than in the control group. At 16 weeks after surgery, exophytic bone formation was made 44.11% in the test groups and 46.26% in the control groups. Exophytic bone formation was made in the test groups more than in the control groups, but there was no statistically significant differences. 3. The membrane was fixed with metal pins to closely contact it to the bone surface. So, collapse and deviation of the membrane could be prevented and in growth of connective tissue also could be blocked from the periphery of the membrane. On the basis of these findings, wee suggest that intraoral experimental model for exophytic bone formation may be effective to evaluate the effect of bone graft material. And it indicates that combined use of membrane and ICB graft material is more effective than use of membrane only for exophytic bone formation.

• Current Research on Agriculture and Life Sciences
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• 제7권
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• pp.201-219
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• 1989

Rice culture in Korea has a long history ranging over two thousand years. In the agriculture economy of pre-mordern Korea, however, its importantce was not as great as generally assumed. In fact, rice culture reached full development only after the 1920s when the Japanese colonial government carried out its drive to increase rice production in the Korea peninsula. It was not until the mid-1930s that rice became the staple in Korean diet. This can be attributed to two factors : (1) a mountainous topography that provides little irrigated fields and (2) a climate characterized by droughts in spring and heavy precipitation in summer. The present paper attempts to answer some of these questions. Specifically it will focus on these : Did the development of rice culture actually result in population growth? What are the salient features of agricultural develdpment and population grow in traditional Korea? Does the case of Korea conform the prevailing generalization about the agriculture in East Asia? I have discussed the development of rice culture and population growth in the Chos$\breve{o}$n dynasty, focusing on the relation between the rapid spread of transplanting and the rapid growth of population from the seventeenth to the nineteenth century. Here are my conclusions. (1) The spread of transplanting and other technological innovationsc contributed to the rapid growth of population in this period. However, we should also note that the impact of rice culture on population growth was rather limited, for rice culture was not the mainstay of agricultural economy in pre-modern Korea. Indeed we should consider the influence of dry field cropsn population growth. Nevertheless, it is obvious that the proliferation of rice culture was a factor crucial to population growth and regional concentration. (2) How should we characterize the spread of rice culture in the whole period? Evidently rice culture spread from less then 20% of cultivated fields in the fifteenth century to about 36% of them in the early twentieth century. Although rice as a single crop outweighed other crops, rice culture was more then counter-balanced by dry field crops as a whole, due to Korea's unique climate and geography. Thus what we have here in not a typical case of competition between rice culture and day field culture. Besides, the spread of rice culture in the seventeenth and eighteenth centuries accomplished by technological innovations that overcame severe springtime drought, rather than extensive irrigation. Althougt irrigarion facilities did proliferate to some extent, this was achieved by local landlords and peasants rather than the state. This fact contradicts the classical thesis that the productivity of rice culture increased through the state management of irrigation and that this in turn determined the type of society. (3) We should further study other aspects of the transition from the stable population and production struture in the fifteenth and sixteenth centuries to the rapid population growth and excessive density of population thereafter. We should note that there were continuing efforts to reclaim the land in order to solve the severe shortage of land. Changes also took place in the agricultural production relations. The increase in land producrivity developed tenancy based on rent in kind, and this in turn increased the independence of tenants from their landlords. There were changes in family relations-such as the shift to primogeniture as an effort to prevent progressive division of property among multiplying offspring. The rapid population growth also produced a great mass of propertyless farm laborers. These changes had much to do with the disintegration of traditional social institutions and political structure toward the end of the Chos$\breve{o}$n dynasty.

• 구강회복응용과학지
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• 제30권2호
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• pp.121-130
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• 2014

목적: Reciprocating 파일인 WaveOne과 continuous rotary 파일인 ProTaper와 ProFile로 근관 형성시 상아질 벽의 표면성상과 상아질 삭편 크기와 도말층 제거 효과를 비교하였다. 연구 재료 및 방법: 60개 단근치를 ProFile, ProTaper, WaveOne으로 성형 후 근관이 보이도록 grinding 하였다. 근관 성형 동안 상아질 삭편을 모아 건조하였다. Scanning electron microscope으로 상아질 삭편 크기와 근관 표면의 불규칙성과 도말층을 관찰하였다. 결과: 표면 함요부의 범위는 ProFile, ProTaper 그리고 WaveOne에서 $150{\mu}m$, $70{\mu}m$, 그리고 $80{\mu}m$의 범위 내에서 관찰되었다. 상아질 삭편의 크기는 ProFile, ProTaper 그리고 WaveOne에서 $7{\mu}m$, $6.5{\mu}m$, 그리고$4{\mu}m$의 범위 내에서 관찰되었다. 도말층은 WaveOne의 중간 1/3과 근단 1/3에서 유의하게 더 많이 관찰되었다. 결론: WaveOne은 중간 1/3과 치근단 1/3의 도말층 제거 효과를 제외하고, ProFile과 ProTaper와 근관 표면 성상과 상아질 삭편에서 큰 차이가 없는 것으로 사료된다.