• 제목/요약/키워드: Good extension

검색결과 649건 처리시간 0.031초

2-GOOD RINGS AND THEIR EXTENSIONS

  • Wang, Yao;Ren, Yanli
    • 대한수학회보
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    • 제50권5호
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    • pp.1711-1723
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    • 2013
  • P. V$\acute{a}$mos called a ring R 2-good if every element is the sum of two units. The ring of all $n{\times}n$ matrices over an elementary divisor ring is 2-good. A (right) self-injective von Neumann regular ring is 2-good provided it has no 2-torsion. Some of the earlier results known to us about 2-good rings (although nobody so called at those times) were due to Ehrlich, Henriksen, Fisher, Snider, Rapharl and Badawi. We continue in this paper the study of 2-good rings by several authors. We give some examples of 2-good rings and their related properties. In particular, it is shown that if R is an exchange ring with Artinian primitive factors and 2 is a unit in R, then R is 2-good. We also investigate various kinds of extensions of 2-good rings, including the polynomial extension, Nagata extension and Dorroh extension.

Correction of Short Nose Deformity Using a Septal Extension Graft Combined with a Derotation Graft

  • Paik, Moo Hyun;Chu, Lo Shui
    • Archives of Plastic Surgery
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    • 제41권1호
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    • pp.12-18
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    • 2014
  • In patients having a short nose with a short septal length and/or severe columellar retraction, a septal extension graft is a good solution, as it allows the dome to move caudally and pushes down the columellar base. Fixing the medial crura of the alar cartilages to a septal extension graft leads to an uncomfortably rigid nasal tip and columella, and results in unnatural facial animation. Further, because of the relatively small and weak septal cartilage in the East Asian population, undercorrection of a short nose is not uncommon. To overcome these shortcomings, we have used the septal extension graft combined with a derotation graft. Among 113 patients who underwent the combined procedure, 82 patients had a short nose deformity alone; the remaining 31 patients had a short nose with columellar retraction. Thirty-two patients complained of nasal tip stiffness caused by a septal extension graft from previous operations. In addition to the septal extension graft, a derotation graft was used for bridging the gap between the alar cartilages and the septal extension graft for tip lengthening. Satisfactory results were obtained in 102 (90%) patients. Eleven (10%) patients required revision surgery. This combination method is a good surgical option for patients who have a short nose with small septal cartilages and do not have sufficient cartilage for tip lengthening by using a septal extension graft alone. It can also overcome the postoperative nasal tip rigidity of a septal extension graft.

다양한 건조방법에 따른 목이버섯의 품질 특성 (Quality Characteristics by Various Drying Methods in Ear Mushroom (Auricularia auricula-judae Quel.))

  • 최소라;유영진;안민실;송은주;서상영;최민경;한현아;송영주;김희준;소순영;이기권;김정곤
    • 한국약용작물학회지
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    • 제22권6호
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    • pp.497-503
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    • 2014
  • In order to produce the high quality of dried-ear mushroom, various drying methods such as hot-air drying at $40{\sim}80^{\circ}C$, freeze drying and drying in vinyl house were carried out. Drying hours of hot-air drying, freeze drying and drying in vinyl house were 12.5~21.5, 36.0 and 72.0 hrs, respectively. Vitamin $D_2$ content of sample was the highest as $6.77{\mu}g/g$ DW in drying in vinyl house and then followed by freeze drying as $5.90{\mu}g/g$ DW and hot-air drying as $1.89{\sim}5.01{\mu}g/g$ DW. After dry, external appearance and color of mushrooms applied hot-air drying and drying in vinyl house were better than freeze-dried one. After rehydration, water uptake of sample in drying in vinyl house and hot-air drying at $50{\sim}60^{\circ}C$ were 17.8 and 19.3~21.0 times, respectively. The methods of drying in vinyl house and hot-air drying at $50{\sim}60^{\circ}C$ also led to high hardness, good shape and resilience. As the results of production of dried-ear mushroom with high quality, we suggest that the best method for drying is the drying in vinyl house due to not only high vitamin $D_2$ content, good external appearance and color after drying but also high hardness and good shape after rehydration.

고식미 갈색 팽이버섯 신품종 '흑향'의 육성 및 특성 (Characteristics and breeding of a new brown variety 'Heukhyang' with good taste in Flammulina velutipes)

  • 김민자;장후봉;최재선;이관우;주경남;김이기
    • 한국버섯학회지
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    • 제13권2호
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    • pp.103-107
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    • 2015
  • 팽이버섯 신품종 '흑향'은 '갈뫼'와 수집 야생균주인 'CBMFV-10'으로부터 분리한 단포자를 교배함으로써 육성된 품종으로, 갓 색이 진한 갈색을 나타내며, 재배기간이 짧고, 식미감이 매우 우수하다. 병재배 시 배양 기간은 23일, 초발이 소요일수는 6일, 생육일수는 17일로 총재배기간이 46일이 소요되어 대조 품종 '갈뫼'에 비해 8일이 단축되었다. 갓 직경과 두께가 갈뫼에 비해 크거나 두꺼웠고, 갓 색은 진한 갈색을 나타냈다. 수량은 850 ml병 당 135 g으로 갈뫼 150 g 대비 10% 감소하였다. 하지만, 야생 팽이버섯처럼 식미감이 매우 우수하여, 차별화된 색과 맛으로 백색 팽이버섯 틈새시장 공략에 유리할 것으로 판단된다.

큰느타리버섯 갓우수 품종 육종 (Breeding of King Oyster Mushroom, Pleurotus eryngii Carrying Good Traits of Cap)

  • 임착한;김민근;제희정;김경희;김선영;김계자;박성자;하영아;김미진;김설화;류재산
    • 한국균학회지
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    • 제40권3호
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    • pp.145-151
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    • 2012
  • 갓모양이 우수한 계통과 대길이가 길고 속성형질을 가진 계통을 모본으로부터 교배육종으로 두 가지 형질을 모두 가진 우수품종을 육성하고자 하였다. 낮은 갓명도 형질의 동형접합체를 만들기 위하여 KNR2312 유래 단핵균사들로 자가교배를 실시하여 갓명도가 45.2, 품질이 6.5인 중간모본 KNR2312-2636-$10{\times}18$을 선발하였고, 이를 A8B10(나) 유래 단핵균사와 이종교배 하였다. 이후 낮은 품질을 개선하기 위하여 KNR2312 유래 단핵균사와 여교배를 실시하여 갓명도가 49.5, 품질이 7.3 수확량이 95.1 g인 가5나5KNR2312-47KNR2312-$12{\times}38$ 계통을 선발하였다. 선발된 계통은 갓모양이 우수하고 특히 갓끝이 24mm로 다듬기나 유통중 파손이 적을 것으로 사료된다.

A study of selection operator using distance information between individuals in genetic algorithm

  • Ito, Minoru;Sugisaka, Masanori
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.1521-1524
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    • 2003
  • In this paper, we propose a "Distance Correlation Selection operator (DCS)" as a new selection operator. For Genetic Algorithm (GA), many improvements have been proposed. The MGG (Minimal Generation Gap) model proposed by Satoh et.al. shows good performance. The MGG model has all advantages of conventional models and the ability of avoiding the premature convergence and suppressing the evolutionary stagnation. The proposed method is an extension of selection operator in the original MGG model. Generally, GA has two types of selection operators, one is "selection for reproduction", and the other is "selection for survival"; the former is for crossover and the latter is the individuals which survive to the next generation. The proposed method is an extension of the former. The proposed method utilizes distance information between individuals. From this extension, the proposed method aims to expand a search area and improve ability to search solution. The performance of the proposed method is examined with several standard test functions. The experimental results show good performance better than the original MGG model.

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농촌지도사업 프로그램 평가와 농촌지도사의 역할 (The Roles and Challenges of Agricultural Extension Program Evaluation)

  • 박덕병
    • 농촌지도와개발
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    • 제10권1호
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    • pp.43-56
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    • 2003
  • Evaluation in both an art and a science. The art of evaluation involves working with the management to agree upon purpose and users of results, creating design and gathering information that are appropriate for a specific situation and a particular policy making context. The value of evaluating extension p개grams has received a lot of attentions recently, and many extension educations see evaluation as an integral part of their work. The science of evaluation involves determining standards and developing indicatiors, selecting methods appropriate to gather information in a systematic way, analyzing information to assist in determining the value of the program in an objective manner. First, extension specialists have to consider relative merits about methods of gathering evaluation data. Selection of method should be influenced by the type of information desired, time availability, and cost of using the method. Second, good evaluations involve stakeholders at all stages including planning, implementation, and utilization of results. Third, far from being an "add-on ," evaluation begins with the initial planning of an educational program. Fourth, it is important for extension specialists that although evaluation is valuable and essential in any effective program, one of the biggest mistakes of extension program evaluators in to promise results that cannot possibly solve all the problems of project.

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적색 반겹꽃 절화용 거베라 '레드옥션' 육성 (A New Gerbera Cultivar, 'Red Auction' with Red Color and Semi-double for Cut Flower)

  • 정용모;황주천;진영돈;김수경;노치웅;이영병;권오창
    • 원예과학기술지
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    • 제29권6호
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    • pp.641-644
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    • 2011
  • 경남농업기술원 화훼연구소에서 적색 대륜계 '01-120-195'를 모본, 적색 대륜계 '미스티레드'를 부본으로 인공교배를 실시하여 적색 대륜계 거베라 'Red Auction'을 육성 하였다. 특성검정 포장에 정식하여 2006년부터 2008년까지 3회에 걸쳐 생육 및 수량특성 검정을 실시하였다. 'Red Auction'은 선명한 적색(RHS 45-A)품종으로 화경이 강건하고 안정된 화형을 가진 반겹꽃 대륜화이다. 년간 주당평균수량은 약 49본 정도이며, 평균 절화수명은 약 12일 정도이다. 'Red Auction' 품종은 2010년 신품종으로 품종보호등록 되었다.