• Weed & Turfgrass Science
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• 제2권3호
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• pp.274-282
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• 2013

본 실험은 ISTA 변온 및 자연실온 환경에서 퍼레니얼 라이그래스 신품종의 종자 발아력, 초기발아속도 및 발아피크기간 등의 특성을 연구 비교해서 실무적으로 한지형 잔디의 설계, 시공 및 관리에 활용하고자 시작하였다. 실험 I은 ISTA 변온(8시간: 광조건, $25^{\circ}C$; 16시간: 암조건, $15^{\circ}C$), 실험 II는 $5-25^{\circ}C$로 유지되고 있는 실내 실온환경에서 수행하였다. 퍼레니얼 라이그래스 종자의 발아력, 초기발아속도 및 발아피크기간은 발아환경 및 품종에 따라 유의한 차이가 나타났다. 종자 발아력은 ISTA 변온환경에서 66.00-93.75%, 자연실온 환경에서 66.25-93.50%로 나타났다. 초기발아속도는 ISTA 변온에서 'Pennant II', 'Brightstar II', 'Sonata', 'Accent II' 품종, 자연실온에서는 'Pennant II' 및 'Brightstar II' 품종이 우수하였다. 품종별 발아피크 기간은 ISTA 변온 환경에서 1.48-5.65일, 자연실온에서는 2.17-10.63일로 나타났다. 발아환경에 관계없이 'Sonata', 'Pennant II' 및 'Brightstar II' 품종의 발아피크 기간이 짧았고, 발아피크 기간이 가장 긴 품종은 'Revenge GLX' 이었다. 본 실험 결과 종자 발아력, 초기발아속도 및 발아피크기간을 종합적으로 고려 시 ISTA 변온에서는 'Pennant II', 'Brightstar II', 'Sonata' 및 'Accent II' 품종이 우수하였다. 그리고 자연실온 환경에서는 'Pennant II' 및 'Brightstar II' 품종이 우수한 것으로 판단되었다.

• 한국환경복원기술학회지
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• 제12권3호
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• pp.72-82
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• 2009

Research was initiated to investigate early establislment characteristics and germination pattern of perennial ryegrass (PR, Lolium perenne L.). Eight varieties of PR were evaluated in the study. An alternative environmental condition for a PR germination test required by International Seed Testing Association (ISTA) was applied in the experiment, consisting of 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$ (ISTA conditions). Daily and cumulative germination pattern were measured and analyzed daily for 30 days. Significant differences were observed in germination pattern, days to the first germination, days to 50% germination, days to 75% germination, and final germination rate. Germination rates were variable among the varieties, being 66.00 to 93.75% at the end of study. There were considerable variations in early germination characteristics and germination pattern among PR varieties. The first germination in all entries tested was initiated from 3 to 5 DAS (days after seeding) under ISTA conditions, being 2 days in differences among the varieties. It was 4 to 7 DAS in days to the 50% germination, being 1 to 3 days later from the first germination and three days were variable among them. Days to the 75% germination were 5.93 to 10.50 DAS under ISTA conditions, being 4.57 days in variety differences. Pennant II and Brightstar II were the fastest varieties. The slowest ones were Revenge GLX and Brightstar SLT. Considering days to the first germination, days to 75% germination, and germination pattern etc, Pennant II and Brightstar II were regarded as excellent varieties under ISTA conditions. From tills study, information on differences in germination characteristics and pattern would be usefully applied for golf course design and construction, when established with PR.

• 한국환경복원기술학회지
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• 제18권3호
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• pp.23-38
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• 2015

The study was initiated with Kentucky bluegrass (KB, Poa pratensis L.) to investigate germination and early establishment characteristics of new cultivars for a practical application to turfgrass establishment such as parks, athletic field and golf course etc. Fifteen cultivars were evaluated in different experiments. An alternative condition for a KB germination test required by International Seed Testing Association (ISTA) was applied in Experiment I, consisting of 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$ (ISTA conditions). Experiment II was conducted under a room temperature condition of 5 to $25^{\circ}C$ (natural conditions). Seed germinating vigor, germination speed and germination peak time were measured in both experiments. Significant differences were observed in seed germinating vigor, germination speed and germination peak time. Seed germinating vigor was variable with different environments and cultivars. It was 75.25 to 89.50% under ISTA conditions and 75.75 to 90.25% under natural conditions. There were considerable variations in early germination characteristics among KB cultivars according to different environments. Early germination characteristics showed that all cultivars were 3 to 5 days faster in germination under ISTA conditions, when compared with natural conditions. The germination speed, measured as days to seed germination of 50% to 80%, was much faster with 'Midnight II', 'Excursion' and 'Midnight' under ISTA conditions. But it was faster with 'Midnight II', 'Excursion' and 'Odyssey' under natural conditions. Differences was also observed in germination peak time with cultivars and growing conditions. It ranged 5.94 to 14.88 days under ISTA conditions and 4.71 to 13.06 days under natural conditions. Regardless of the environment conditions, the shortest cultivars were 'Odyssey' and 'Midnight II'. The longest ones were 'Nuglade' under ISTA condition and 'Moonlight' under natural conditions. Considering germinating vigor, germination speed and germination peak time, 'Midnight II', 'Excursion', 'Midnight', and 'Odyssey' were regarded as excellent cultivars under ISTA conditions in terms of early establishment characteristics, while 'Midnight II', 'Excursion', 'Odyssey', and 'Courtyard' under natural conditions. These results suggest that an intensive germination test be needed prior to planting, for investigating the early germinating vigor, germination speed and germination peak time. Also, a proper cultivar selection and comprehensive site analysis for the growing environmental conditions should be done before turfgrass establishment such as golf course construction.

• 한국환경복원기술학회지
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• 제17권5호
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• pp.1-17
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• 2014

Research was initiated to investigate early establishment characteristics and germination pattern of Kentucky bluegrass (KB, Poa pratensis L.) under natural room temperature and to analyze differences between alternative and natural conditions for a practical application. Fifteen cultivars of KB were evaluated in the study. Daily and cumulative germination pattern were measured and analyzed on a daily basis. Differences were observed in germination percentage, germination pattern, days to the first germination and days to 75% germination. Germination percentage was variable with cultivars at the end of study. It was 75.75 to 90.25% under natural condition. There were considerable variations in early germination characteristics and germination pattern among KB cultivars according to germination conditions. The first germination in all entries tested was initiated between 6 and 9 DAS (days after seeding) under ISTA (International Seed Testing Association) condition. But it was observed between 9 and 12 DAS under natural condition, being 3 to 5 days later as compared with ISTA condition. On the first date of a germinating process, the germination rate was 0.25% to 25.00% under ISTA condition, while 0.50% to 13.25% under natural condition. Days to the 75% germination were 15.08 to 28.80 DAS under ISTA condition and 17.78 to 28.75 DAS under natural condition. Midnight II, Excursion and Midnight were the fastest cultivars under ISTA condition, while Odyssey the fastest one under natural condition. Regardless of germination condition, the slowest cultivar was Voyager II, being over 4 weeks to 75% germination percentage. For the most cultivars, days to 75% germination under natural room temperature condition were 1 to 8 days slower than under ISTA condition. From this study information on differences in germination characteristics and pattern among cultivars would be usefully applied for KB establishment such as golf course construction. Prior to on-site seeding, a comprehensive germination test is practically recommended due to a possible decline in germination capability during domestic distribution and storage after import.

• 한국음향학회지
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• 제39권4호
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• pp.246-254
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• 2020

본 논문에서는 학습 기반 압축 센싱 기법을 이용한 측면주사 소나 영상의 비균일 잡음 제거 알고리즘을 제안한다. 제안하는 기법은 Iterative Shrinkage and Thresholding Algorithm(ISTA) 알고리즘을 기반으로 하고 있으며 성능 향상을 위해 학습네트워크의 비선형성을 강화시키는 전략을 선택하였다. 제안된 구조는 입력 신호를 비선형 변환과 초기화 하는 부분, Sparse 공간으로 변환 및 역변환하는 ISTA block, 특징 공간에서 픽셀 공간으로 변환하는 부분으로 구성된다. 제안된 기법은 다양한 모의 실험을 통해 잡음 제거 성능 및 메모리 효율성 측면에서 우수함이 입증되었다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.713-721
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• 2004

Variable air intake and variable exhaust nozzle of hypersonic engines are designed and tested in this study. Dimensions for variable geometry air intake, ram combustor and variable geometry exhaust nozzle are defined based on the requirements of a pre-cooled turbojet engine. Hypersonic Ramjet Engine is designed as a scaled test bed for each component. Actuation forces of moving parts for variable intake and variable nozzle are reduced by balancing the other force in the opposite direction. A demonstrator engine which includes variable intake and variable nozzle is designed and the components are fabricated. Composite material with silicone carbide is applied for high temperature parts under oxidation environment such as leading edge of the variable intake and combustor liner. Internal cooling structure is adopted for both moving and static parts of the variable nozzle. Pressure recovery and mass capture ratio of the variable intake at Mach 5 is obtained by a hypersonic wind tunnel test. Flow characteristics of the variable nozzle are obtained by a low temperature flow test. Wall temperature and heat flux of the nozzle at Mach 3 is obtained by a firing test. As results, the intake and the nozzle are proved to be used at designed pressure and temperature environment.

• 한국환경복원기술학회지
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• 제11권5호
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• pp.79-91
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• 2008

Research was initiated to investigate germination characteristics of creeping bentgrass (CB, Agrostis palustris Huds.). Seven varieties of CB were evaluated with different experiments. An alternative environment condition requiring for a CB germination test by International Seed Testing Association (ISTA) was applied in the Experiment I, consisting of 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$(ISTA conditions). Experiment II was conducted under a room temperature condition of 5 to $25^{\circ}C$(natural conditions). In each experiment, data such as seed germinating vigor, early germination characteristics, germination speed and germination peak time were measured. Significant differences were observed in seed germinating vigor, early germination characteristics, germination speed and germination peak time. Seed germinating vigor was variable with different environments and varieties. It was 61.50 to 98.25% under ISTA conditions and 55.00 to 98.50% under natural conditions. There were considerable variations in early germination characteristics among CB varieties according to different conditions. Early germination characteristics indicated that all varieties were 1 to 4 days faster in germination under ISTA conditions, when compared with natural conditions. The germination speed, measured as days to seed germination of 70% and 90%, was much faster with Penn A-1, Penn A-4 and Penncross under ISTA conditions. But it was even faster with L-93 and Penncross when grown under natural conditions. Differences were also observed in germination peak time with varieties and growing conditions. It was 0.57 to 2.86 days under ISTA conditions and 0.74 to 1.74 days under natural conditions. Regardless of the environment conditions, the shortest variety was L-93 and the longest one T-1. Considering germinating vigor, early germination characteristics, germination speed and germination peak time, Penn A-1, Penn A-4 and Penncross were regarded as excellent varieties under ISTA conditions in terms of early establishment characteristics, while L-93, Penn A-1 and Penncross under natural conditions. These results suggest that an intensive germination test be needed prior to planting, for the early germinating vigor, germination speed and germination peak time. Also, a proper variety selection and comprehensive site analysis for the growing environmental conditions should be done before golf course construction.

• 아시안잔디학회지
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• 제23권1호
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• pp.23-34
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• 2009

톨 훼스큐 종자의 발아율, 발아패턴 및 발아특성은 생육환경과 품종에 따라 차이가 크게 나타났다. 자연 실온 환경에서 발아력은 ISTA 변온과 약간 다르게 나타났고 최종 발아율은 $85.25{\sim}97.00%$ 사이로 다양하였다. 톨 훼스큐의 발아패턴은 최초 발아의 경우 ISTA 변온에 비해 $2{\sim}3$일 정도 늦은 치상 후 $7{\sim}9$일 사이에 시작되었다. 최초 발아 시기는 공시 품종 간 1일 정도 차이가 있었으며, Arid III 및 Olympic Gold 품종이 $7{\sim}8$일 사이로 다소 빨랐다. 발아율 50%에 도달한 기간은 최초 발아 후 $3{\sim}4$일 경과 후인 치상 후 $11{\sim}12$일 사이로 나타났으며, 이것은 ISTA 변온에 비해 $3{\sim}4$일 정도 늦은 것이었다. 또한 실무적으로 요구되는 발아율 76% 도달기간은 ISTA 변온에 비해 품종에 따라 $1.55{\sim}4.77$일 정도 늦은 치상 후 $12.38{\sim}14.29$일 사이로 나타났다. 공시 품종 중 75% 발아율 도달 기간이 가장 빠른 품종은 Olympic Gold 품종이었고, 반대로 가장 느린 종류는 Tar Heel II 품종이었다. 톨 훼스큐 품종 간 발아특성 및 발아패턴의 결과를 종합적으로 고려할 때 Olympic Gold 품종이 가장 우수한 것으로 사료되었다. 본 실험을 통해 밝혀진 품종 간 생리 생태적 특성과 ISTA 변은 및 자연 실온 조건 간 비교 자료는 골프장 등 잔디밭 조성 시 실무적인 기초 자료로 유용하게 활용될 수 있을 것이다.

• 한국환경복원기술학회지
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• 제13권4호
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• pp.30-41
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• 2010

Research was initiated to investigate germination characteristics and germination pattern of creeping bentgrass (CB, Agrostis palustris Huds.). Seven varieties of CB were evaluated in the study. An alternative condition for a CB germination test required by International Seed Testing Association (ISTA) was applied in the experiment, consisting of 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$ (ISTA conditions). Daily and cumulative germination patterns were measured and analyzed on a daily basis. Significant differences were observed in germination pattern, days to the first germination, days to 50% germination, days to 85% germination, and germination percentage. Germination rates were different among the treatments at the end of study. There were significantly considerable variations in early germination characteristics and germination pattern among CB varieties. The first germination in all entries was initiated between 4 and 5 DAS (days after seeding) under ISTA conditions. Generally, the first germination percentage was 5 to 25%. However, such Penn-series varieties as Penn A-1, Penn A-4 and Penncross were much more vigorous over others, resulting in 50 to 75% in the first germination percentage. It took 4 to 10 DAS in reaching to days to the 50% germination, being 5 days in difference among the varieties. Days to the 85% germination were 5.90 to 11.75 DAS under ISTA conditions, being 5.85 days in variety difference. It means 1 to 2 days after days to 50% germination. Penn A-1 was the fastest variety, while T-1 the slowest one. Considering days to the first germination, days to 85% germination, and germination pattern etc, Penn A-1, Penn A-4, Penncross and L-93 were regarded as excellent varieties under ISTA conditions. From this study, in-depth information on germination characteristics and pattern would be usefully applied for golf course design and construction, when established with CB.

• 아시안잔디학회지
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• 제25권1호
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• pp.1-10
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• 2011

본 실험은 자연 실온 환경에서 크리핑 벤트그래스 신품종의 초기 발아특성 및 발아패턴을 조사하고, 그리고 변온 및 자연실은 환경에서의 그 차이점을 비교 분석해서 실무 시공에 응용할 수 있는 기초자료를 파악하고자 시작하였다. 공시재료는 크리핑 벤트그래스 7품종이었으며, 일일 발아패턴 및 누적 발아패턴을 1일 간격으로 조사하였다. 크리핑 벤트그래스 종자의 발아율, 발아패턴 및 발아특성은 온도 조건 및 품종에 따라 차이가 크게 나타났다. 공시 품종 모두 최초 발아는 ISTA 변온환경 에서 치상 후 4-5 일 사이에 시작되었지만, 자연 실온 환경에서는 대부분 품종이 ISTA 변온보다 2~3일 늦은 6~8일 사이에 시작되었다. 최초 발아 시 발아율은 ISTA 변온에서 일반적으로 5~25% 정도였고, 'Penn A-1', 'Penncross' 및 'Penn A-4' 품종의 최초 발아율은 50~70% 정도로 초기 발아가 대단히 왕성하였다. 하지만 자연 실온 환경에서 최초 발아율은 일반적으로 5~10% 정도였으며, 'Penncross', 'L-93' 및 'Penn A-4' 품종은 20~50% 정도로 초기 발아 특성이 대단히 왕성하였다. 크리핑 벤트그래스에서 발아율 50% 도달 기간은 ISTA 변온에서는 치상 후 4~10일 사이에 나타났고, 자연 실온에서는 품종에 따라 ISTA 변온보다 2~5일 정도 늦은 치상 후 6~15일 사이에 나타났다. 발아율 85% 도달 기간은 ISTA 변온에서는 치상 후 5.90~11.75일 사이였으며, 가장 빠른 종류는 'Penn A-1' 품종이었다. 하지만 자연 실온에서는 ISTA 변온보다 다소 늦은 치상 후 7.95~12.50일 사이였고, 가장 빠른 종류는 'L-93' 품종이었다. 그리고 온도 조건에 관계없이 기준 발아율 도달 기간이 가장 느린 품종은 ISTA 변온 및 자연 실온에서 각각 11.75일 및 12.50일로 나타난 'T-1' 품종이었다. 본 실험 결과 나타난 이러한 발아특성 비교 데이터는 골프장 등 잔디밭 조성 시 실무적인 기초 자료로 유용하게 활용될 수 있을 것이다.