• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.169-172
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• 2003

Intact seeds of burcucumber (Sicyos angulatus L.) are not nearly germinated so that the farmers remove their arils before sowing. The study was carried out to measure the effort of aging, chilling, washing, chemical treatment, drying, and their sequential treatments on the germination of ones with arils and the seedling emergence. The seeds extruding over 1mm of their radicles and the seedlings with fully expanded cotyledons were counted daily for calculating the germination and the seedling emergence rates. Seedcoat softening using 10% NaOH solution somewhat enhanced their germination rate of the intact seeds harvested in the current year, but aging treatment done on 6 days at $45^{\circ}C$ after NaOH treatment increased the germination rate more than only NaOH treatment. A day washing after the NaOH treatment and a day chilling after the washing increasingly elevated the rates as well. Irrigation of 0.2% $\textrm{KNO}_3$ solution, moreover, showed the greatest germination rate of the priming treatments done during all the 7 day chilling. Drying the seeds after the combined treatment of chilling and priming more inclined the germination rate than nondrying ones, but red light treated during 24 hour desiccation was more effective in the germination rate increment than dark condition. The seeds done the sequential treatments of aging, NaOH, washing, combining chilling and priming and drying under red light illumination were germinated up to 80% but seedlings were emerged to 60%, lower than ones removed their arils.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.2
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• pp.169-176
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• 2018

In this paper, we consider duty-cycled wireless sensor networks (WSNs) in which sensor nodes are periodically dormant in order to reduce energy consumption. In such networks, as the duty cycle interval increases, the energy consumption decreases. However, a higher duty cycle interval leads to the increase in the end-to-end (E2E) delay. Many applications of WSNs are delay-sensitive and require packets to be delivered from the sensr nodes to the sink with delay requirements. Most of existing studies focus on only reducing the E2E delay, rather than considering the delay bound requirement, which makes hard to achieve the balanced performance between E2E delay and energy consumption. A few study that considered delay bound requirement require time synchronization between neighboring nodes or a specific distribution of deployed nodes. In order to address limitations of existing works, we propose a duty-cycle scheduling algorithm that aims to achieve low energy consumption, while satisfying the delay requirements. To that end, we first estimate the probability distribution for the E2E delay. Then, by using the obtained distribution we determine the maximal duty cycle interval that still satisfies the delay constraint. Simulation results show that the proposed design can satisfy the given delay bound requirements while achieving low energy consumption.

• School Mathematics
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• v.5 no.4
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• pp.507-520
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• 2003

본 연구는 실질적인 의미에서 학생들로 하여금 수학을 더 잘 이해할 수 있도록 돕기 위해 테크놀로지를 학교 교실에서 직접 활용하는 방안에 대한 연구이다. 특히 여기서는 수학을 가르치고 배우는 과정에서 가상학습체계가 주요한 도구로서 적용되었다. 내용은 무게중심을 택했고 12명의 중학생을 대상으로 현직교사가 직접 지도하였다. 학생들은 수업초기에 교사에 의해 소개되는 학생중심 학습활동에 강한 관심과 호기심을 보였고 집중력이 아주 강했다. 전통적인 수업방식과는 달리 학생들이 참여하였고 테크놀로지를 이용하여 전통적인 방식의 교실에서 할 수 없었던 수업의 시작은 학생들의 호기심을 자극하는데 충분하였다. 전반적으로 테크놀로지 환경에서의 수업을 선호하였지만 아직 전통적인 방식인 칠판과 분필을 이용한 수업을 선호한 학생들도 있었다. 새로운 변화도 좋지만 새로운 환경에 친화적이지 않거나 테크놀로지를 이용한 수업의 빠른 진행이 학생을 오히려 혼란하게 만들기도 하였다. 마지막으로 교사는 가상학습체계를 교실에서 활용함에 있어서 현 교육과정과 교과서를 크게 개혁하지 않아도 잘 준비되고 계획된 테크놀로지의 활용에 대한 잠재력을 확인할 수 있었다. 우리는 현재 테크놀로지의 보급에 비해 그 활용도가 낮다는 것을 잘 알고 있고 기타 입학시험이라는 현실이 교육과정과 학습방법의 개혁을 현실적으로 추진하는 것이 어려운 일임을 잘 알고 있다. 그래서 현 상황에서 테크놀로지의 사용을 가능하게 할 수 있는 방법을 모색하였다. 이미 보급된 테크놀로지와 교사와 학생의 테크놀로지에 대한 이해가 앞으로 그 잠재력을 갖고 있다고 확인하였다.보다 낮은 일반세균수 값을 보여주었다. 봄철 시료에 있어서 소규모 도계장은 본 냉각 후 도계과정을 제외하곤 모든 도계공정 단계에서 대규모 도계장보다 높은 일반 세균수의 측정값을 보여주었다. 봄철 시료의 냉각말기의 냉각수 일반세균수는 소규모 도계장이 대규모 도계장보다 높은 측정값을 보여주었다.주었다.다.㏖/s/$m^2$에서는 이앙후 각각 18일로 두 품종 모두 늦어, 약광은 유묘기에 분화되었던 분얼아를 휴면으로 유도할 수 있음을 시사하였다. 4. 유효경비율은 1220~220 $\mu$㏖/s/$m^2$에서 다산벼는 47~55%, 화성벼는 100~72%로 다산벼가 화성벼보다 낮았다. 이것은 다산벼는 무효분얼이 많다는 것을 시사하는 것으로 품종 육성시 유효경비율을 높여야 할 것이다.타났고, \circled2 회복상태에서, 10 lu$\chi$인 경우 서간에 1.26 $\mu\textrm{V}$, 야간에 1.59 $\mu\textrm{V}$였고, 100 lu$\chi$인 경우 서간에 2.63 $\mu\textrm{V}$ 야간에 3.65 $\mu\textrm{V}$였으며, 400 lu$\chi$인 경우 서간에 2.52 $\mu\textrm{V}$, 야간에 3.67 $\mu\textrm{V}$로 나타났다.히, 흉선, F냥, 비장 등의 림프구에 초기 세포용해성 감염을 일으키는데, B

• Korean Journal of Weed Science
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• v.7 no.1
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• pp.19-28
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• 1987

These experiments were conducted to recognize the germination change in relation to storage period, using 25 kinds of field-collected weed seeds stored under the dry and low temperature ($4{\pm}1^{\circ}C$), and to establish a simple germination induction methods in some kinds of them. No or weak dormancy was observed in Lepidium virginicum, Rumex japonicus, Cirsium japonicum var. ussuriense, Aeschnomene indica and Ludwigia prostrate. The germination of Digltaria sanguinalis, Portulaca oleracea, Amaranthus spp., Echinochloa crux-galli, Polygonum persicaria, Cyperus iria, and Aeschynnmene indica was enhanced by $H_2SO_4$ treatment for 20, 2, 2, 50, 40, 3 or 5 minutes, respectively. Favorable germination in Polygonum persicaria and Echinochloa crus-galli was obtained by soaking in water for 25 days and 50 days, respectively. Moisture treatment for 21 days and 14 days caused the enhancement of germination in Cyperus difformis and Aneilema keisak, respectively. Combination of various treatments in Cyperus iria was most effective when the seeds treated with $H_2SO_4$ for 3 minutes incubated in alternating temp. after soaking in 0.2% $KNO_3$, but their effect on Digitaria sanguinnlis was little.

• Weed & Turfgrass Science
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• v.3 no.3
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• pp.232-239
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• 2014

Zoysiagrass seeds had low germination or lack of germination uniformity under natural condition. To improve the final germination percentage of zoysiagrass seeds, we investigated the methods of proper pre-treatment to enhance germination rate of zoysiagrass. Seeds were subjected to the testa scarification and four types of seed priming methods, namely, hydro priming (distilled water), osmotic priming (polyethylene glycol -0.5 MPa, -1.0MPa, -2.0 MPa), halo priming (Potassium nitrate 100 mM, 200 mM, 400 mM), and solid matrix priming (seed : microcel-E : distilled water = 4:1:8) with and without 25% KOH treatment in the testa. The scarification improved the germination rate and reduced the germination time. Osmotic priming (PEG -0.5 MPa) with scarification were significantly increased the seed germination rate and decreased MGT, and $T_{50}$. Seed germination rate obtained by osmotic priming (PEG -0.5MPa) with scarification increased above 60% in comparison with natural condition. Conclusively, scarified and primed zoysiagrass seed germinated more rapidly and uniformly in the study. The present results suggested that PEG priming treatment with KOH treatment prior to sowing could improve germination percentage, and this method makes us establish the early zoysiagrasses in the field.

• Journal of Practical Agriculture & Fisheries Research
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• v.15 no.1
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• pp.183-202
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• 2013

The demand of ginseng which has attracted many people for a long time has expanded further with great spotlight ; but it has caused anxiety of some safety-sensitive customers due to unavoidable pesticides and its weakness for disease and insect pest. On the other hand, sluggish studies on effective doses of ginseng and red ginseng which is produced and processed after hardship have worsened confusion of customers. Against this backdrop, this study is about to find out measures for safe ginseng cultivation and effective dose of white or red ginseng which are safely produced and reaches meaningful conclusions as follows ; As for a study to minimize the use of chemical fertilizers and pesticides or to change them into environmentally-friendly products, ginseng cultivation utilizing Lime Sulfur complex might be an alternative. The effects of Lime Sulfur complex are great on ginseng seeding with under 200 times compound KHCO3 and five-year-old ginseng with over 200 times compound using NaHCO3. When using with green materials like Bordeaux mixture, there would be great potential to realize ginseng without pesticide use.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.47-47
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• 2022

단자엽식물은 잎의 곡선과 직선의 조화가 아름다워 관상용으로 가치가 높은 식물이다. 이로 인해 자생 단자엽식물의 실내 관상 및 조경용 소재개발 연구가 활성화되고 있으나 재배에 대한 정보는 미비한 실정이다. 본 연구에서는 국내 자생 단자엽식물인 참김의털[Festuca ovina L. var. coreana (St.-Yves) St.-Yves], 청사초(Carex breviculmis R.Br.), 골풀[Juncus decipiens (Buchenau) Nakai]을 대상으로 몇 가지 재배 조건에 대한 생육 차이를 확인하였다. 국립생물자원관으로부터 분양 받은 세 종의 종자는 휴면 여부와 발아 적온을 확인하기 위해 종자를 페트리디쉬에 파종한 후 15, 20, 25, 30℃(명 또는 암조건) 및 25/15℃(16/8h, 명/암) 조건에 배치하였다. 재배실험은 유리온실에서 수행되었으며, 토양에 파종 후 4주간 육묘한 다음 균일한 생육상태의 묘를 7cm 포트에 이식하여 실험의 재료로 사용하였다. 토양실험은 시판 원예용상토와 마사토를 혼합하여 사용하였으며, 비율을 1:1, 2:1 및 3:1로 조성하였다. 차광 환경은 55, 75% 차광과 무차광 조건으로 달리 하였으며, 추비는 재배 6, 8, 10주차에 500, 1,000ppm의 하이포넥스(NPK 7-10-6) 용액을 엽면시비 하였다. 토양실험을 제외한 모든처리구에서는 원예상토 단용을 사용하였으며, 이식 후 12주간 재배하였다. 발아 실험 결과, 참김의털은 명조건에서 25/15와 15℃를 제외하고 발아율이 10% 이하로 조사되었으며, 암조건에서 온도가 증가할수록 발아율이 감소하였다. 청사초는 모든 온도에서 90%이상 발아하였으며, 암조건의 경우 발아율이 10% 이하로 조사되어 광발아성 종자로 확인되었다. 골풀은 실험이 진행된 30일 동안 모든온도에서 발아하지 않았으나, 재배실험을 위해 토양에 파종된 골풀은 파종 약3주 이후 발아가 관찰되었다. 재배실험 결과, 참김의털과 청사초의 경우 2:1로 혼합한 토양에서 엽수와 분얼수, 생체중 등이 가장 높게 조사되어 관상적 가치가 높았으며, 골풀은 3:1의 혼합토양에서 생육이 가장 우수하였다. 차광은 세 종 모두에게서 생육에 부정적인 영향을 미쳤으며, 청사초와 골풀은 500ppm의 하이포넥스를 시비하였을 때 생육이 촉진되었다.

• Korean Journal of Weed Science
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• v.8 no.3
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• pp.309-316
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• 1988

Several experiments were conducted to investigate the achene viability and growth characteristics of Eclipta prostrata (L.) L. No dormancy and no after-ripening requirement were found for E. prostrata achenes. When achenes were stored at room temperature, germination did not decrease with up to 5 months storage. Large differences in loss of viability of E. prostrata achenes occurred when different dehydration methods were used. Immediate dehydration resulted in high viability, but slow dehydration resulted in severe loss of viability. Achene viability at shallow burial depths (5 and 10 cm deep) was lower under upland soil conditions than under lowland soil conditions. Seedling growth was greatly reduced when flooding to a depth of 10 cm occurred at or before the 4-leaf stage. Flooding after the 4-leaf stage stimulated stem elongation. Branching started from the second week and usually terminated at the tenth week. Leaf size was determined by the branch which are related to the assimilate supply. Flowering of E. prostrata started during the fifth week after emergence, and mature achenes were produced from the sixth week. Ten to 14 days were needed for the achenes to mature. About 14,000 achenes were produced on each plant. Achene production per week increased from the sixth week to the tenth week and thereafter it declined. The average number of achenes per inflorescence decreased with delay in flowering.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.6 no.4
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• pp.259-264
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• 2001

Typhoon and neap tide on Cochlodinium polykrikoides bloom and water temperature on disappearance of C. polykrikoides bloom were investigated to elucidate the outbreak mechanism of C. polykrikoides blooms at Naro and Namhae coastal area in South Sea of Korea. The first observation of C. polykrikoides blooms were observed when thermocline was disappeared by typhoon, tide, etc. The first blooms of C. polykrikoides were observed on neap tide or before one day from neap tide in 1996-1998 and 2000. However, thermocline was disappeared by typhoon in 1994 and 1999, the first blooms were observed early 12-30 day than 1996-1998 and 2000. The main reason of disappearance of C. polykrikoides blooms after typhoon on 1997-2000 seems to be other environmental change by typhoon rather than low water temperature. In the future, the first C. polykrikoides bloom will be appear around the first neap tide of latter part of August with breaking down of thermocline, but if the thermocline be collapsed by typhoon in July, the C. polykrikoides bloom will be appear at beginning of August. The outbreak of C. polykrikoides blooms will be explain as follows: The vegetative cells, which was germinated by environmental change or already exist in surface water at low level, input to the surface water, and then nutrients and trace metals which were suppled from out side of C. polykrikoides bloom area inflow to surface. The vegetative cells are growth by the nutrients and trace metals at suitable environmental conditions e.g. water temperature, salinity, and sufficient light.

• Korean Journal of Weed Science
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• v.16 no.2
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• pp.114-121
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• 1996

This study was conducted to investigate seed germination, seedling growth, and responses to herbicides of Bidens tripartita L. When the field-collected seeds were stored under a dry-room temperature, dry-low temperature, wet-low temperature, or dry-high temperature condition, no seeds were germinated in a growth chamber with 14 hr photoperiod up to 35 days after the storage. Exceptionally, however, some seeds stored under a wet-room temperature condition were germinated after 25 days of the storage. This might be due to the fact that the seed coats were damaged by fungi which developed during the storage. Seeds stored under a wet-low temperature condition (stratification) began to be germinated after 3 months of the storage and the germination rate increased with a prolonged stratification. Almost all seeds were germinated after 9 months of the stratification. These results suggest that the dormancy of B. tripartita L. seeds relate to the seed coat and thus several attempts were made to induce seed germination through damaging or weakening the seed coat. Freezing($-20^{\circ}C$), drying($100^{\circ}C$), or swelling($40^{\circ}C$) of the seeds was not effective to induce the germination. Treatments of concentrated sulfuric acid, $KNO_3$, or gibberellin to the seeds had no effect on inducing the germination. However, ethrel had a stimulatory effect on the germination of the seeds with an optimum concentration of 250ppm. A seed cutting was also effective to induce the germination, but seedlings from the seeds had cutted cotyledons. Germination of the stratified seeds varied with the temperature condition to which they were subjected, but not with light. The germination rate was the highest at 35 - $40^{\circ}C$. Although the seeds were not able to germinate under a submerged condition, seedlings after 2-leaf-stage exhibited better growth under a submerged or a subirrigated condition than under an upland condition. Among the herbicides tested, pyrazosulfuton-ethyl, linuron, and bentazone were found to be effective for controlling B. tripartita L., having more herbicidal effect with an earlier application.