• 제목/요약/키워드: Emergence rates

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Emergence of Curbside Pickup: Consumers' Usage Intention Amid COVID-19 Pandemic

  • Zihsyuan Liua;Youngsok Bangb
    • Asia pacific journal of information systems
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    • 제32권1호
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    • pp.51-69
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    • 2022
  • This study examines how consumers' intention to use a curbside pickup responds to the COVID-19 vaccination rates. With our first survey conducted in March 2021, we find that a low (high) vaccination rate is associated with consumers' high (low) intention to maintain contact avoidance and their high (low) anticipation for shipping delays. Heightened contact avoidance and anticipation for shipping delays may encourage consumers to use a curbside pickup. Our results also show that when a product is needed immediately, and a consumer expects shipping delays, s/he is more likely to use a curbside pickup. However, with our second survey conducted in November 2021, we find heterogeneous consumer responses to the vaccination rates. Specifically, consumers' political affiliation moderates the relationship between the vaccination rates and their intention to maintain contact avoidance. The association between the vaccination rates and the anticipation for shipping delays is also weakened compared to March 2021. Our empirical results illustrate how consumers' intention to use a curbside pickup emerges and changes amid the COVID-19 pandemic.

Solar Flare Rate and Probability depending on Sunspot Classification and Its Area Change

  • Lee, Kang-Jin;Moon, Yong-Jae
    • 천문학회보
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    • 제36권2호
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    • pp.98-98
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    • 2011
  • We have investigated solar flare probability depending on sunspot classification, its area, and its area change using solar white light data. For this we used the McIntosh sunspot groups with most flare-productive regions : DKI, DKC, EKI, EKC, FKI and FKC. For each group, we classified it into three sub-groups according to sunspot area change : increase, steady, and decrease. For sunspot data, we used the NOAA active region information for 11 years (from January 2000 to December 2010): daily sunspot class and its area corrected for the projection effect. As a result, we find that the mean flare rates and the flare probabilities for the "increase" sub-groups are noticeably higher than those for other sub-groups. In case of the (M+X)-class flares of 'kc' groups, the mean flare rates of the "increase" sub-groups are more than two times than those of the "steady" sub-groups. This is statistical evidence that magnetic flux emergence is an very important for triggering solar flares since sunspot area increase can be a good proxy of magnetic flux emergence. In addition, we have examined the relationship between sunspot area and solar flare probability. For this, we classified each sunspot group into two sub-groups: large and small. In the case of compact group, the solar flare probabilities noticeably increase with its area.

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훼손비탈면의 한지형 잔디 파종량에 따른 자생식물의 생육특성에 관한 연구 (A Study on the Growth Characteristics of Native Plants by Seeding Amounts of Cool-season Turfgrasses on the Disturbed Slope)

  • 김재환;심상렬
    • 한국환경복원기술학회지
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    • 제12권5호
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    • pp.1-12
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    • 2009
  • This research was initiated to investigate the revegetation characteristics under the seeding amount treatments of cool-season turfgrasses on the disturbed slope. 4 different seeding amounts of cool-season turfgrasses (0.0 $g/m^2$, 1.5 $g/m^2$, 3.0 $g/m^2$, 6.0 $g/m^2$) with the same seeding amounts of native woody (Rhus chinensis, Albizzia julibrissin) and herbaceous plants (Lotus corniculatus var. japonicus, Dianthus sinensis, Aster yomena) were treated with 3 replications on the experimental disturbed slope. Data such as soil hardness (mm), moisture content (%), surface coverage rate (%), the number of each germinating plant and plant height were analyzed. There were no statistic differences observed in the soil hardness and the soil moisture content while a significant difference was observed in the surface coverage rates. The surface coverage rates were higher in 3.0 $g/m^2$ and 6.0 $g/m^2$ plots compared to the rest two plots of cool-season turfgrasses. However, the emergence of native woody and herbaceous plants was relatively low in 3.0 $g/m^2$ and 6.0 $g/m^2$ plots of high seeding amounts of cool-season turfgrasses. This result indicated that high seeding amounts of cool-season turfgrasses could decrease the emergence of native woody and herbaceous plants. We concluded that 1.5 g~3.0 $g/m^2$ seeding amounts of cool-season turfgrasses was optimum level for the balanced emergence of cool-season turfgrasses, native woody and herbaceous plants in the viewpoint of the ecological disturbed slope revegetation.

진딧물천적인 진디혹파리(Aphidoletes aphidimyza)의 생물학적 특성 (Biological Characteristics of the Aphid-eating Gall-midge, Aphidoletes aphidimyza (Diptera: Cecidomyiidae) as a Biological Control Agents of Aphids)

  • 정영석;최용석;오인석;한규홍;서미자;윤영남
    • 한국응용곤충학회지
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    • 제42권3호
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    • pp.241-248
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    • 2003
  • 진딧물의 포식자인 진디혹파리(Aphidoleres aphidimyra)의 온도와 먹이에 따른 발육기간, 산란력, 부화율, 우화율, 포식능력, 번데기의 저온저장, 살충제에 대한 감수성 등의 생물학적 특징을 조사하였다. 복숭아혹진딧물을 먹이로 공급하였을 경우, 알에서 성충까지의 평균 발육기간은 15$^{\circ}C$에서 40일, 3$0^{\circ}C$에서 12일이 소요되었다. 또한 목화진딧물을 먹이로 공급하는 경우에는 이보다 짧아 각각 37일과 11일이 소요되었다. 번데기를 저장하는 경우에는 5$^{\circ}C$에서는 1주일, 1$0^{\circ}C$에서는 2주일 동안 보관하여도 90%이상의 우화율을 나타내었으나, 그 이상 저장하는 경우베는 우화율이 점차 떨어지는 경향을 나타내었다. 성충은 우화 2-3일 후에 교미를 하고 알을 낳기 시작하여 평균 10일동안 약 200여개의 알을 낳는다. 대부분의 성충은 오후 6시에서 8시 사이에 우화하고 주로 야간에 활동하였다.

유채(Brassica napus L.) 종자의 발아와 초기생장을 억제하는 식물정유의 선발 (Selection of Essential Oils Inhibiting Germination and Initial Growth of Rapeseed (Brassica napus L.))

  • 최성환;박기웅;손영걸;안재영;이증주
    • 한국잡초학회지
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    • 제30권3호
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    • pp.199-205
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    • 2010
  • 본 연구는 19종의 식물정유가 유채종자의 발아 및 생장에 미치는 영향을 파악하기 위하여 수행되었다. 그 결과 식물정유를 100배 희석 처리 한 경우 anise, cinnamon, citronella, clove, geranium, lemongrass, mustard 및 pine oil 등의 8종은 유채의 발아를 완전히 저해하였으며, 초기생장의 저해효과도 큰 것으로 나타났다. 유채의 발아와 초기생장에 대한 저해율을 근거로 하여, 상기의 8개의 식물정유로부터 cinnamon, clove 및 geranium oil이 실용 가능성이 있는 bio-herbicide로서 선발되었다. 선발된 cinnamon, clove 및 geranium oil을 토양처리한 경우 90kg ai $ha^{-1}$농도에서 유채의 출현율은 각각 7.1, 25.0, 3.6% 였으며, 초기생장율도 22.0, 9.9 및 11.0% 수준으로, 유채종자의 발아와 초기생장억제에 미치는 효과가 큰 것으로 나타났다.

播種 前 담배 종자에 가하여지는 $GA_3$와 光質 處理가 幼苗 出睍과 生長에 미치는 影響 (Presowing Treatment Effects of GA3 and Light Quality on Seedling Emergence and Growth of Tobacco)

  • 강진호
    • 한국자원식물학회지
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    • 제11권3호
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    • pp.290-295
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    • 1998
  • Presowing treatements to seed are reasonable for elevating the seedling production efficiency. This experiment was carried out to determine the effects of $GA_3$ [0 (water) : 0.01 mM] and light qulaity (red : white) simultaneously treated before sowing on seedling emergence and growth of tobacco (Nicotiana tabacum L.) cv NC 82 and Burley 21. Red or white light was illuminated 12 hours a day while seeds of the cultivars were imbibed with either water or $GA_3$ 0.01 mM for 3 days. Seedling emergence was measured up to 20 days after sowing but morphological characters and dry weights were done 40 days. The seedling emergence rate of cv NC 82 was more affected by light quality and $GA_3$ pretreatments than that of cv Burley 21. Light quality more influenced the rate than $GA_3$ while red light or water imbibition enhanced the rates of the two cultivars compared to the other treatement. Although mean plant height and leaf number per seedling were nearly equal between the treatements, red light declined leaf area per seedling of cv Burley 21 of which seeds were imbibed in water but white light decreased the areas of both cultiars of which seeds were soaked in $GA_3$solution. Shoot dry weight was greater in cv NC 82 but less in cv Burley 21 pretreated with red light, and root dry weight showed the reverse result in white light, meaning that presowing light and $GA_3$ treatments could be changed the seedling development and growth of tobacco.

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사료용 피의 건답과 무논 파종 시 입모 및 초기생육특성 (Seedling Emergence and Initial Growth between Water and Dry Seeding in Forage Millet)

  • 안석현;정남진
    • 한국작물학회지
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    • 제59권1호
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    • pp.83-88
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    • 2014
  • 제주피의 발아특성 및 파종 심도에 따른 초기 생육 특성을 조사한 결과를 요약하면 다음과 같다. 가. 사료피 1호 종자는 $15^{\circ}C$ 이상에서 발아가 가능하였으며, $10-25^{\circ}C$의 범위에서 $20^{\circ}C$에서 가장 높은 발아율을 보였다. 나. 입모율은 담수와 직파에서 모두 $20^{\circ}C$에서 가장 높았으며, 담수직파에서 평균 입모율은 5.9%, 건답직파는 70.5%로 나타났다. 다. 사료피 1호의 출아가 가능한 종자의 최대 파종 깊이는 담수직파에서 15, 20, $25^{\circ}C$에서 0.5, 1.8, 1.5 cm, 건답직파는 각각의 온도에서 9.5, 10.0, 9.9 cm로 파종조건과 온도에 따라 변이를 보였다. 라. 사료피 1호는 담수와 건답직파 모두에서 온도와 관계없이 파종심도와 중배축장이 정의상관관계를 보여, 출아에 중배축 신장이 가장 크게 영향을 미치고 있을을 알 수 있다.

온도가 쌀보리와 맥주보리의 출엽속도와 출엽간격에 미치는 영향 (Effects of Temperature on Leaf Emergence Rates and Phyllochron of Naked and Malting Barley)

  • Kang, Young-Kil;Ko, Koan-Su;Kang, Bong-Kyoon
    • 한국작물학회지
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    • 제38권5호
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    • pp.449-457
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    • 1993
  • 온도가 쌀보리와 맥주보리의 출엽속도와 출엽간격에 미치는 영향을 구명하고자 쌀보리 3품종(능쌀보리, 새쌀보리, 향천과 001)과 맥주보리 3품종(두산 8호, 사천006, 진광보리)을 향온 7수준(4, 8, 12, 16, 20, 24, 28$^{\circ}C$)과 변온 7수준[6/2(명기 / 암기), 10/6, 14/10, 18/14, 22/18, 26/22, 30/$25^{\circ}C$]으로 유지시킨 생장상에서 4엽기까지 키우면서 매일 주간엽수를 조사하여 출엽속도 및 출엽간격를 산출한 결과를 요약하면 다음과 같다. 항온과 변온에 관계없이 공시품종 모두 동일 온도내에 있어서는 출아후 일수가 증가됨에 따라 주간 출엽수도 직선적으로 증가되었다. 평균기온 28$^{\circ}C$를 제외하고는 출아속도와 출아간격이 항온과 변온간에 현저한 차이를 보이지 않았다. 출아속도와 출아간격은 품종간에 유의한 차이가 있었고 동일 품종내 온도간에도 현저한 차이가 있었다. 평균기온이 증가됨에 따라 일당 출아속도는 출아 최적온도까지 곡선적으로 증가된 다음 감소되었는데, 6품종의 출아 최적온도는 20.1~21.5$^{\circ}C$로 품종간 현저한 차이는 없었으나 출아 최적온도에서의 출엽속도는 쌀보리가 0.202~0.226엽/일, 맥주보리가 0.231~0.241엽/일으로 맥주보리가 큰 경향이었다. 평균이온이 증가됨에 따라 유효적산온도당 출엽속도는 지수함수적으로 감소되었고, 출엽간격(일엽당 적사온도)은 지수함수적인 증가를 보였는데, 6품종의 평균 출엽간격은 4$^{\circ}C$에서 46.2GDD/엽, 28$^{\circ}C$에서 129.3GDD/엽이었다.

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탄닌 함유 사초식물의 발아 및 생육특성 (Germination and Growth Characteristics of Tannin Containing Forage Crops)

  • 허삼남;이성운;최순호;차장옥
    • 한국초지조사료학회지
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    • 제21권4호
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    • pp.211-216
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    • 2001
  • In an effort to investigate the germination and growth characteristics of tannin containing forage crops (such as chicory, birdsfoot trefoil, Lotus pedunculatus, sulla, lespedeza, crownvetch, sainfoin), germinativity, seedling vigor, and productivity were studied. Although the cumulative germination percentage (CGP) of chicory and birdsfoot trefoil was low, the germination rate(GR) and days to reach 50% of final germination(Gt50) were excellent. Crownvetch, lespedeza and sainfoin showed poor germination. Chicory seeds were light but the rate of emergence and establishment were high. Seeds of Lotus pedunculatus and birdsfoot trefoil were also small, but their rates of emergence and establishment were quite good. On the other hand, seeds of sainfoin and crownvetch were heavy but their emergence and establishment rate were very low. Lespedeza was the best in getting over the hot summer, and crownvetch also survived well during summer. Chicory was good in productivity and early growing but its persistence was not good. In case of birdsfoot trefoil and Lotus pedunculatus their early growing were slow but their productivity and persistence were fairly well. Lespedeza, crownvetch, and sainfoin showed poor growth in Korea. Based on the results of this study it can be concluded that chicory would be better to use as short term high productive forage crop, and Lotus pedunculatus and birdsfoot trefoil could be used as continuous functional forage crops in Korea. (Key words : Tannin. Germination. Chicory. Birdsfoot trefoil, Lotus pedunculatus)

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인공사료에 의한 파밤나방의 대량사육법 (Simple Mass-Rearing of Beet Armyworm, Spodoptera exigua (Hubner) (Lepidoptera : Noctuidae) on an Artificial Diet)

  • 고현관;이상규;이비파;최현문;김상화
    • 한국응용곤충학회지
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    • 제29권3호
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    • pp.180-183
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    • 1990
  • 인공사료에 의한 실내사육에서 부활율은 97.9%, 3령까지의 생존율은 83.3%였다. 3령유충에서의 용활율은 톱밥을 이용한 집단사육에서 82.5%, 개체사육에서 48.5%, 집단사육에서 37.5%로서 톱밥을 이용한 집단사육에서 가장 높았다. 유화율은 톱밥을 이용한 집단사육에서 90.9%, 개체사육에서 85.2%, 집단사육에서 86.7%로 거의 비슷하였다. 톱밥을 이용한 집단 사육법은 개체사육법에 비하여 사육방법이 용이하고 인공사료의 양을 줄일 수 있다.

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