• Title/Summary/Keyword: row cover

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Effect of Row Covers on the Growth and Yield of Broccoli During Spring Culture (막덮기 재배가 봄재배시 녹색꽃양배추의 생육 및 수량에 미치는 영향)

  • 이정수;이재욱;성기철
    • Journal of Bio-Environment Control
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    • v.11 no.4
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    • pp.175-180
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    • 2002
  • This study was conducted to examine the effect of row covering materials on the growth and yield of broccoli for early production in the open meld. Materials for plastic tunnel were row-covering (ventilating non-woven fabric), perforated film (2.3% pore space) and P.E. film. The types of row covers were tunnel and covering period was one months after transplanting. The row cover and perforated film increased daily air and soil temperature by 3~4$^{\circ}C$ and 2~3$^{\circ}C$, respectively as compared to no covering. Also, relative humidities in those treatments were higher than those in P.E. and no covering. The row covering and perforated film enhanced plant growth. Broccoli grew best and abnormal head appeared the least with row covering treatment. Days taken for head formation, however, did not differ between treatments but the weight of curd was over 400 g in the treatment of row covering and perforated film covering. Marketable yield doubled under row covering as compared to no covering. The first harvest time was earlier by two weeks in row-covering. The results of this experiment indicated that covering row-cover film in spring cultivation was effective fer not only yield increase but also quality evaluation in early production of broccoli.

Vibration Analysis for LP Turbine Blade Damage (저압터빈 블레이드 손상에 대한 진동 해석)

  • Kim, Hee-Soo;Bae, Yong-Chae;Kim, Yeon-Hwan;Lee, Hyun;Kim, Sung-Hwi
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.752-757
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    • 2003
  • The steady stress, modal analysis for the damaged blade was carried out to evaluate the integrity of LP 4 blade row. As a result, 4 dangerous modes for LP blade row were found in the interference diagram and it was confirmed that the nozzle passing frequency has nothing to do with the blade failure. And then the dynamic stress are analysed for the 4 dangerous modes. There are some points far out of maximum allowable stress in the cover and tenon. Therefore the blade is not safe according to the Goodman judgement. So the manufacturer have modified the design of cover and tenon. Until now, the power plant is being operated without special problems.

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CHANGE DETECTION OF LAND COVER ENVIRONMENT IN THE HAMPYEONG-BAY, KOREA USING LANDSAT DATA

  • Lee Hong-Jin;Chi Kwang-Hoon;Jang Se-Won
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.402-402
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    • 2005
  • The purpose of this study is to analyze the land cover environment changes of tidal flat in the Hampyeong Bay. Especially, it centers on the changes in the sedimentary environment using remote sensing data. Multi-temporal Landsat data (Path-Row: 116-034) were used in this study. Remote sensing data can be effectively applied for quantitative analysis of geological environment changes in the Hampyeong-bay.

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Design of the helical array antenna for the domestic broadcast satellite (국내 위성방송 수신용 헬리컬 어레이 안테나의 설계)

  • 맹성옥;최학근
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.8
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    • pp.1747-1754
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    • 1997
  • The helical array antenna is designed for domestic DBS(Directcast Satellite) reception. The antenna diameter is determined 30cm with 168 element s to cover from Moojoo (beam center) to Seoul. The helical antenna with 2-turns and 4.deg. pitch angle is chosen as array elements for good axial ratio and antenna height. In array antenna design, row distance is 0.787.lambda., array distance is 0.824.lambda. in the same row. The feed is constructed using the radial waveguide to decrease the height of antenna. The measured values of the designed antenna are not only satisfied with the design goals but also similar to theoritical values except the axial ratio.

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Effects of Row Cover Materials on the Micro Environment and the Growth of Leafy Vegetables (엽채류 간이 터널 재배 시 피복자재별 미기상 환경 및 생육)

  • Lee, Jae-Wook;Lee, An-Hee;Seong, Ki-Cheol;Um, Young-Cheol;Park, Dong-Kum
    • Journal of Bio-Environment Control
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    • v.18 no.4
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    • pp.326-331
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    • 2009
  • This study was carried out to evaluate the effects of row cover materials supported by flexible FRP frames with three kinds of non-woven fabric, and five kinds of net in leaf vegetable cultivation. Leaf radish (Raphanus sativus L.), Chinese cabbage (Brassica rapa L. ssp. pekinensis) were sown on May 21, 2003, and leaf lettuce (Lactuca sativa L.) was planted at the same date in Agricultural Research Center for Climate Change, Jeju, Korea. Net coverings showed higher light transmittance than in non-woven fabric coverings. The average air and soil temperatures increased by $0.3{\sim}1.0^{\circ}C$ in net coverings and $0.5{\sim}3.0^{\circ}C$ in non-woven fabric coverings, respectively. There was no difference in relative humidity among the covering materials. All the vegetables showed higher growths and yields in non-woven coverings than in non-covering. The yields increased 81% in leaf lettuce, 58% in leaf radish, and 93% in Chinese cabbage, respectively. In addition, the insect damages were considerably reduced in the row covering plots than in the control, especially in non-woven fabric coverings.

A Study on the Formation and Urban Dwellings of Chinese Town in Malaysia (말레이시아 화인거리의 형성과정과 도시주거에 관한 연구 -말레이시아 말라카와 싱가포르를 중심으로-)

  • Lee, Sang-Hun;Yoon, In-Suk
    • Journal of architectural history
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    • v.7 no.4 s.17
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    • pp.175-190
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    • 1998
  • The formation of Chinese Town in Malacca of Malaysia and Singapore would explain that Chinese gradually played an important role of commerce and urban service according to the Western European advance to southeast Asia and the construction of colonial cities from the 16th century to 19th and massed residence in many cites of southeast Asia. Chinese was usually separated from the Western European by western colonial policy and city planning. Common architectural characteristics in Chinese towns of Malaysia can refer to the transmission of the Chinese architectural material, the combination of dwelling and commerce in a house and the space organization centered on a court or an air well in the narrow and long site, lying adjacent to street etc. The Chinese dwellings in Malaysia rooted with Chinese settlement in southeast Asia. The Chinese dwellings was not always a shop on 1th floor and a dwelling on 2nd floor before the 19th century. But as Chinese immigration and commercial activity progressed in earnest in the early of 19th century, the row house of Chinese for dwelling was autonomously changed to two functional shophouse for dwelling and commerce. Chinese row house can refer to the use of Malay regional material, change of symmetrical Chinese traditional housing type by the narrow and long site and the tendency of the eclectic elevation of Western and China. Another architectural characteristics of the shophouse is an appearance of the continuous verandah with a cover regulated by Stamford Raffles in Singapore. This regulation was applied to architecture in Chinese Town as Stamford Raffles constructed Singapore. It was spread to South China reversely and became the regulation of streetscape for the modern city. Shophouse of Chinese towns in Southeast Asia and south China can be understood by context of Chinese immigration, colonialism, housing type of commerce and dwelling and the Western European city planning.

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Weed Occurrence as Influenced by Living Mulch, Soil Incorporation and Cutting Treatment of Rye in Organic Soybean Field (호밀 리빙멀치, 토양환원, 예취처리가 유기농 콩밭 잡초 발생에 미치는 영향)

  • Lee, Byung-Mo;Lee, Ji-Hyun;Oh, Young-Ju;Lee, Sang-Bum;Kang, Chung-Kil;Jee, Hyeong-Jin;Lee, Jong-Hyung
    • Korean Journal of Weed Science
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    • v.30 no.2
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    • pp.164-170
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    • 2010
  • In organic agriculture, cover crops are used for weed control. Cover crops inhibited weed germination or growth by allelopathy or shading effects. In this study, we used rye as cover crop to control weed in organic soybean field. The main treatment was rye using method such as living mulch, incorporating and mowing. Sub-treatment was rye planting density and soybean planting density. One month after soybean sowing, weed emergency and growth had been highly suppressed by rye in all treatments. Living mulch treatment was the best effective way to control the weed about 92%, and mowing treatment was the second about 75% compare to control. The weed control efficiency between rye planting densities was similar during one month. Soybean planting density treatment was same result as rye planting density. As a result of this experiment, we recommend rye as living mulch in one row planting.

Soil Quality Assessment for Environmentally Sound Agriculture in the Mountainous Soils; Analysis of Sediment Data and Suggestion of Best Management Practices (산지에서의 환경보전형 농업을 위한 토양의 질 평가;유사자료의 분석과 최적영농방법의 제안)

  • Choi, Joong-Dae;Park, Ji-Sung;Kim, Jeong-Je;Yang, Jae-E;Jung, Yeong-Sang;Yun, Sei-Young
    • Korean Journal of Environmental Agriculture
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    • v.19 no.3
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    • pp.201-205
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    • 2000
  • Eleven runoff $plots(3{\times}15\;m)$ were built on a sloping field of a high plateau in Kangwon Province, Korea. The plots were treated with different tillage, residue covers and fertilizers, corn and potato were cultivated, and sediment discharge was measured from the plots for 3 years. Agricultural management practices were monitored around the plots to develop adequate best management practices. The least sediment occurred from the plots with no-till and 100% residue cover $(corn,\;0.1{\sim}2.2\;t/ha/year)$ and with contour tillage and vinyl sheet cover plots $(potato,\;0.1{\sim}0.2\;t/ha/year)$. The largest sediment was measured from the plots with up-and-down till and no cover ($11{\sim}33$ and $16{\sim}31\;t/ha/year$ from corn and potato plots, respectively). The type of organic and commercial fertilizers seemed not to affect sediment discharge. Sediment discharge from contour plots were largely dependent on the collapse of ridges due to the flush of water stored in furrows. The sediment discharge from contour corn and potato plots with no residue cover was $10{\sim}27$ and $16{\sim}24\;t/ha/year$, respectively. No-till with residue cover, vinyl cover for tuber crops, construction of furrow dam, frost heave research, furrow and ridge tillage with furrow dam after tuber crop harvest, limited stalk harvest of row crops, use of winter cover crops, and other common best management practices were recommended to minimize the sediment discharge from a high plateau sloping land culture.

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Arthroscopic Full-Thickness Rotator Cuff Repair in Elderly Patients (고령 환자의 관절경적 회전근 개 봉합술의 결과)

  • Cheon, Sang Jin;Lee, Dong Ho;Park, Yong Geon;Son, Seung Min
    • Journal of the Korean Orthopaedic Association
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    • v.55 no.1
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    • pp.38-45
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    • 2020
  • Purpose: To examine the clinical and structural outcomes of an at least two-year follow-up of arthroscopic full-thickness rotator cuff repairs with a single-row or suture-bridge technique in patients more than 65 years of age. Materials and Methods: Patients diagnosed with a full-thickness rotator cuff tear who were more than 65 years of age, underwent arthroscopic rotator cuff repair after at least six months of conservative treatment, agreed to take a follow-up magnetic resonance imaging (MRI) six months postoperatively, and visited outpatient for at least two years were enrolled in this study. Clinical evaluations were done using The University of California Los Angeles score, Constant Shoulder Score, and visual analogue scale evaluated two years after the surgery. The structural integrity was analyzed using follow-up MRI. During surgery, a suture-bridge technique was used if the rotator cuff tendon could cover half of the footprint under constant tension. Otherwise, single-row repair was performed. Results: The samples were 158 cases, consisting of 93 single-repairs and 65 suture-bridge repairs. A preoperative comparison of the age distribution, fatty degeneration of supraspinatus and infraspinatus muscle, medial retraction of torn cuff tendon, and tear size between the two groups were not significant. The clinical scores were improved significantly in all cases. The distribution of the structural integrity by Sugaya classification were 49 cases in type 1 (31.0%), 62 cases in type 2 (39.2%), 30 cases in type 3 (19.0%), 11 cases in type 4 (7.0%), and six cases in type 5 (3.8%). The re-tear rate of the single-row group was 9.7% (nine out of 93 cases) and 12.3% (eight out of 65 cases) for the suture-bridge group. Conclusion: Satisfactory clinical and radiological outcomes were achieved after arthroscopic full-thickness rotator cuff repair in patients more than 65 years of age. Both single-row and suture-bridge techniques would be beneficial for the elderly.

A Genetic Algorithm for the Maximal Covering Problem (유전 알고리즘을 이용한 Maximal Covering 문제의 해결)

  • 박태진;이용환;류광렬
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 2002.11a
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    • pp.502-509
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    • 2002
  • Maximal Covering 문제(MCP)란 행렬 상에서 n개의 열(column) 중 p개를 선택하여 m개의 행(row)중 최대한 많은 행을 cover하는 문제로 정의된다. 본 논문에서는 MCP를 유전 알고리즘(Genetic Algorithm)으로 해결하기 위해 문제에 적합하게 설계된 교차 연산자(crossover operator)와 비발현 유전인잔(unexpressed gene)를 가진 새로운 염색체 구조를 제시한다. 해결하고자 하는 대상 MCP의 규모가 매우 큰 경우 전통적인 임의교차(random crossover) 방법으로는 좋은 결과를 얻기가 힘들다. 따라서 본 연구에서는 그리디 교차(greedy crossover) 방법을 제시하여 문제를 해결한다. 그러나 이러한 그리디 교차를 사용하더라도 조기 수렴 등의 문제로 인해 타부 탐색 등의 이웃해 탐색 방법에 비해 그리 좋은 결과를 얻기가 힘들다. 본 논문은 이러한 조기 수렴 문제를 해결하고 다른 이웃에 탐색 방법보다 더 좋은 결과를 얻기 위해 비발현 유전인자(unexpressed gene)를 가진 염색체를 도입하여 해결함을 특징으로 한다. 비발현 유전인자는 교차 과정에서 자식 염색체의 유전인자로 전달되지 않은 정보 중 나중에라도 유용할 가능성이 보이는 정보를 보존하는 역할을 하여 조기 수렴 문제를 해결하는데 도움을 주어 보다 나은 결과를 얻을 수 있게 해준다. 대규모 MCP를 해결하는 실험에서 새로운 비발현 유전인자를 적용한 유전 알고리즘이 기존의 유전 알고리즘뿐만 아니라 다른 탐색 기법에 비해 더욱 좋은 성능을 보여줌을 확인하였다.

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