• Title/Summary/Keyword: maturity method

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Egg Development and Early Life History of the Natural Monument Species Hemibarbus mylodon (Pisces: Cyprinidae) in Korea (천연기념물 어름치 Hemibarbus mylodon (Pisces: Cyprinidae)의 난 발생 및 초기생활사)

  • Ko, Myeong-Hun;Kim, Hae-Rim;Park, Sang-Yong;Bang, In-Chul
    • Korean Journal of Ichthyology
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    • v.29 no.2
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    • pp.101-108
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    • 2017
  • Egg development and early life history of the Korean natural monument fish Hemibarbus mylodon (Pisces: Cyprinidae) were investigated to provide basic data on biological characteristics and ecological recovery. Adult fish were collected from nature and transferred to the laboratory. For the first time, artificial maturation of females and males succeeded after 15 months of indoor culture. Mature eggs and sperm were obtained using Ovaprim injections (0.5 mL/kg) and then the eggs were fertilized using the dry method in the laboratory. The mature eggs were adhesive, turbid, and greyish; they averaged $2.21{\pm}0.06mm$ (n=30) in diameter. The embryos began to hatch about 78 h after fertilization at a water temperature $20{\pm}1^{\circ}C$, and the newly-hatched larvae were $6.6{\pm}0.75mm$ in total length (TL). At 14 days after hatching, the post-larval individuals were $13.5{\pm}0.23mm$ (TL), and their yolk sacs were completely absorbed. Twenty one days after hatching, they entered the juvenile stage and reached $13.5{\pm}0.23mm$ (TL). At 100 days after hatching, their band patterns, external form, and a pair of barbels were similar to those of adults, and they averaged $33.0{\pm}4.25mm$ (TL). The breeding technology and characteristics of early life history obtained in this study will be very helpful for conservation of H. mylodon in nature.

INTERRELATIONSHIP BETWEEN VERTICAL FACIAL TYPE AND DENTAL MATURATION (수직적 안모형태와 치아성숙도의 상관관계에 대한 연구)

  • Koo, Yong-Han;Hyun, Hong-Keun;Kim, Jung-Wook;Jang, Ki-Taeg;Lee, Sang-Hoon;Hahn, Se-Hyun;Kim, Chong-Chul
    • Journal of the korean academy of Pediatric Dentistry
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    • v.37 no.1
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    • pp.57-64
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    • 2010
  • The purpose of this investigation was to study the relationship between vertical facial pattern and dental maturation in children in pubertal and pre-pubertal periods. The material consisted of lateral head films and panoramic radiographs of 1306 patients. The subjects were selected according to Ricketts's VERT index and other including criteria. These subjects were divided by VERT index to brachyfacial group and dolichofacial group. In each selected subject, dental age was determined according to Demirjian's dental maturity score. All subjects were distributed according to age, vertical facial type and sex, mean and standard deviation of chronological age, dental age and age difference were determined in each group. And the data were analysed to find the difference of tooth maturation by facial pattern. Findings of this study include: 1. In all groups, dental age was determined higher than chronological age in statistically significant level. 2. Compared by vertical facial pattern, in pubertal age groups, it seems that subjects with brachyfacial type presented the tendency to have an advanced dental maturation, only in female group. 3. Compared by pubertal period, brachyfacial groups presented more advanced dental maturation in pubertal groups than pre-pubertal groups.

Estimation of Rice Canopy Leaf Area Index(LAI) by Spectral Reflectance of Solar Radiation in Paddy Field (태양광 반사율을 이용한 벼 군락의 엽면적지수 추정)

  • 이정택;이춘우;주문갑;홍석영
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.42 no.2
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    • pp.173-181
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    • 1997
  • To estimate the leaf area index(LAI) of rice plant by non-destructive method, spectral reflectance from rice plant canopy was measured by using the spectroradiometer (LI-1800, LICOR Inc.) with one week interval during the rice growing season at Suwon paddy field in 1993. LAI of two medium late maturing varieties, Daechungbyeo and Ilpumbyeo, and one early maturing variety, Jinbubyeo, were observed and compared with those estimated by vegetation index. The reflectance(R) of visible wavelength remained less than 0.1 over entire growing season, but that of near infrared wavelength remained from 0.1 to 0.5 with the significant positive correlation with LAI. Vegetation index determined by the reflectance of visible against near infrared wavelength showed high correlation with LAI of rice canopy. Vegetation index derived from wide band ratio, NIR(720~1, 100nm) /Blue(400~500nm), showed the highest correlation coefficient with LAI. Vegetation index derived from narrow band(10nm interval) ratio, R910/R460, from transplanting to heading stage corresponded well to measured values (Y=0.16799X-0.79776 ; $R^2$=0.94). But another vegetation index, NIR(720~1, 100nm) /Red (600~700nm), showed higher correlation with LAI than NIR /Blue did from heading stage to maturity.

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A New Variety "Singang" with resistance to Soybean Mosaic Virus by Molecular Marker Assisted Selection (분자표지선발(MAS)을 이용한 콩모자이크병 저항성 신품종 "신강")

  • Lee, Seuk-ki;Moon, Jung-Kyung;Jeong, Kwang-Ho;Seo, Min-Jung;Kim, Yul-Ho;Yun, Hong-Tae;Kim, Jeong-Kon
    • Korean Journal of Breeding Science
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    • v.41 no.4
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    • pp.568-573
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    • 2009
  • A new soybean variety, "Singang", was released by NICS, RDA in 2008. It is resistant to soybean mosic virus (SMV), which is one of the most serious diseases in soybean production. "Singang" had been developed for seven years by molecular marker-assisted selection (MAS) breeding method using recurrent parent, "Sowon", and donor parent, "L29" which has the SMV-resistance gene, Rsv3. Selected promising breeding line, Suwon 242, was evaluated in yield trials for 2 years from 2005 to 2006 at NICS. Regional yield trials were performed for 3 years from 2006 to 2008 in five locations including Jeju. Agronomic characteristics of "Singang" is a determinate growth habit, purple flower color, grey pubescence, yellow testa, light brown hilum and lanceolate leaflet shape. "Singang" showed the similar performance to "Sowon" cultivar. This variety showed 3 days shorter in days to maturity than the check variety (Pungsannamul). The average yield under regional yield trials in five location was 2.78t/ha. It is adaptable to the whole country except for Gangwon province.

A New Rice Variety 'Hwaweon 4' with Durable Resistance to Rice Blast (벼 도열병 저항성 신품종 '화원4호')

  • Kim, Dong-Min;Ju, Hong-Guang;Kang, Ju-Won;Han, Seong Sook;Ahn, Sang-Nag
    • Korean Journal of Breeding Science
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    • v.43 no.6
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    • pp.620-624
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    • 2011
  • 'Hwaweon 4' was developed from a cross between the African upland cultivar, 'Moroberekan' and 'Ilpumbyeo' based on marker-aided backcross selection. The recurrent parent 'Ilpumbyeo' is a high grain quality cultivar with medium to late maturity. 'Hwaweon 4' is nearly isogenic to 'Ilpumbyeo' except a small Moroberekan introgressed segment on chromosome 4 harboring the resistance gene for blast. The preliminary and replicated yield trial was conducted at Chungnam National University in 2006 and 2007. The local adaptability test was carried out by the National Seed Management Office (NSMO) from 2008 to 2009. This cultivar was registered to NSMO with a cultivar designated as 'Hwaweon 4'. This cultivar averaged 76 cm in culm length and has medium growth duration. Milled rice of 'Hwaweon 4' is translucent and the grain quality traits are comparable to those of the recurrent parent. It has low protein content. The yield potential of 'Hwaweon 4' in grain was about 6.31 MT/ha at the ordinary fertilizer level for two years. This variety showed highly resistance reaction at the blast nursery test at four locations and also at the sequential planting method. This resistance is due to the resistance gene designated as Pi45(t) on chromosome 4 introgressed from the donor parent, 'Moroberekan'. The Pi45(t) gene would be useful inenhancing resistance to blast in rice breeding program.

A Study on Spirituality Experience of Recovering Drug Addicts (회복기 마약중독자의 영성 체험에 관한 연구 -기독교·가톨릭인 회복자를 중심으로-)

  • Lim, Hae Young;Kim, Hakju
    • The Journal of the Korea Contents Association
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    • v.18 no.11
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    • pp.98-112
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    • 2018
  • In order to find out policy and practical implications to support recovering drug addicts in a holistic way, This study conducted in-depth interviews with five research participants using Giorgi's phenomenological study method to understand the meaning of spiritual experience of recovering drug addicts. According to data analysis, these spirituality experiences appeared as two thematic themes: 'experience of relationship with a divine being' and 'experience of inherent transcendence'. Three sub-themes of 'fear and scary existence', 'hanging object' and 'embracing existence' were derived from the essence theme of 'experience of relationship with a divine being' and 'immanent transcendental experience' was conceptualized into four sub-themes: 'facing existence', 'psychological reconstruction', 'mental maturity', and 'a way to go alone'. Based on this, spiritual experiences of recovery drug addicts showed that religion itself exerted a considerable influence on their spiritual experience and their spiritual experience was closely related to the recovery of humanity. Also, 'intrinsic transcendental experience' suggested that two essential themes of spiritual experience were closely interrelated in a mutual cyclical relationship. Based on the results, We discusses the major intervention plan for the recovery drug addicts that the social welfare system can consider.

Three Dimensional Skeletal, Dentoalveolar and Airway Space Changes after Slow Maxillary Expansion in Children (어린이에서 저속 상악 확장에 따른 골격성, 치아치조성, 기도 변화에 대한 3차원적 평가)

  • Nawoon Kim;Daewoo Lee;Jae-Gon Kim;Yeonmi Yang
    • Journal of the korean academy of Pediatric Dentistry
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    • v.50 no.2
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    • pp.155-167
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    • 2023
  • The aim of this study was to investigate the effects of slow maxillary expansion (SME) on the dentoalveolar, skeletal, upper airway, and maxillary sinus using cone-beam computed tomography (CBCT). Twenty-three orthodontic patients (mean age 8.93 ± 1.61 years) who were treated with maxillary expansion using banded hyrax in the Department of Pediatric Dentistry at Jeonbuk National University Dental Hospital were included. According to the expansion speed applied, they were divided into two groups: SME (12 subjects, mean age 8.92 ± 1.45 years) and rapid maxillary expansion (RME, 11 subjects, mean age 8.94 ± 1.84 years). CBCT were obtained before (T0) and after (T1) the treatment and were analyzed with InVivo5 software (Anatomage, San Jose, CA, USA). Descriptive statistics showed no significant differences between the two groups in age, sex, or skeletal maturity. There were significant increases in maxillary width at the dentoalveolar and skeletal levels for both groups. Upper airway volume revealed a significant increase of 38.59% in the SME group and 28.72% in the RME group. However, there was no significant difference between SME group and RME group in all measurements. This study suggested the efficacy of SME in growing patients. SME was effective in increasing not only dentoalveolar and skeletal measurements but also airway volume. Therefore, pediatric dentists should select an appropriate expansion method considering the physiological aspects of periodontal tissues and discomfort in growing children.

Effect of Plant Density and Planting Date on Growth and Grain Yield of Maize Hybrids (파종기와 재식밀도가 단교잡종옥수수의 생육 및 종실수량에 미치는 영향)

  • Cho, J.Y.;Kwon, H.J.;Kang, Y.K.;Jong, S.K.
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.28 no.2
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    • pp.227-232
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    • 1983
  • Two single cross maize hybrids planted on May 4 and 25 and June 15, 1982 were grown at 40,000:55,000 70,000 and 85,000 plants per hectare to evaluate plant density effect on growth and grain yield at different planting dates. Two hybrids with different leaf angle (Suweon 19 with horizontal leaves and Suweon 58 with erect leaves) and the same maturity were used. The number of days from planting to silking varied from 74 to 58 days as planting was delayed from May 4 to June 15. However, growing degree days from planting to silking was about $810^{\circ}C$ regardless planting dates. Grain yields of two hybrids were significantly decreased as planting was delayed. The number of ears per 100 plants and the number of kernels per ear of two hybrids were linearly decreased with increasing plant density. The optimum plant density for Suweon 19 estimated by Duncan's method was about 55,000 plants hectare for May 4 and 25 plantings and decreased to 32,000 plants/hectare for June 15 planting. The optimum density for Suweon 58 was estimated to be about 71,000 plants/hectare for May 4 planting and 54,000 plants/hectare for May 25 planting, respectively.

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A Study on the Improvement of the TRA Framework for Complex Weapon Systems from the System Integration Perspective (시스템 통합 관점의 복합 무기체계 기술성숙도 평가 프레임워크 개선에 관한 연구)

  • Jiin Koo;Sukjae Jeong
    • Journal of The Korean Institute of Defense Technology
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    • v.5 no.2
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    • pp.23-30
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    • 2023
  • TRA(Technology Readiness Assessment) quantitatively assesses the current level of domestic technology and is used as a key tool for determining the possibility of domestic R&D and risk management. However, since the current TRA utilizes hardware-oriented TRL(Technology Readiness Level), it is suitable for independent assessment of each technologies, but has limitations in evaluation from a system integration perspective. In addition, the checklist-based assessment is highly likely to involve subjective evaluation. This study proposes an enhanced TRA framework by redefining TRA procedures and criteria from the systems integration perspective of system engineering. We focused on developing a framework that overcomes the limitations of the current TRL/TRA and enables easier and more intuitive assessment. The proposed framework distinguishes between TE(Technology Element) and CTE(Critical Technology Element) in terms of HW, SW and interface and redefines TRL. TRA is performed according to the TRL redefined from the above three points of view, and the lowest evaluation value is used as system maturity level in consideration of risk management. The proposed CTE selection method minimizes the intervention of the evaluator by utilizing the quantitative goal of the key ROC(Required Operational Capability), development difficulty, and application of COTS(Common Off The Shelf) technology. The effectiveness of this framework was confirmed through a case study of the TSS(Target Surveillance System). It is hoped that starting with this study, research at the framework level will be activated and contribute to the improvement of the TRA system.

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Characteristics of posteroanterior cephalometric analysis in children with skeletal Class I malocclusion (성장기 골격성 I 급 부정교합 환자의 정모두부방사선 계측의 특징)

  • Moon, Yoon-Shik;Kim, Jung-Kook;Jung, Hyun-Sung;Sung, Sang-Jin
    • The korean journal of orthodontics
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    • v.31 no.2 s.85
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    • pp.159-172
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    • 2001
  • Three dimensional analysis of malocclusion and craniofacial deformation is essential for the successful orthodontic treatment. But the orthodontists are not familiar with diagnosis and treatment plane based on lateral cephalometric analysis. Since orthodontists do not posses a sufficient knowledge in standard value of posteroanterior cephalometric anaysis and of clinical importance for transverse jaw growth. In this study male(n=130) and female(n=171) aged from 6 to 16 and diagnosed as Class I malocclusion were selected to analysis width of cranium, maxilla and mandible on the posteroanterior cephalogram. The changes as a function of chronologic age and cervical vertebrae maturity index(CVXI) were examined. The Proper regression model was selected by sex with polynominal regression models and method of variable selection. Mean of each measurements and 70% confidence interval of individual measurement according to age was assesed and a graphs were made. Results are as follows :1. All the measurements for the width are gradually incresed as increase in chronologic age and CVMI. From the total amount of change between age 6 and 16, there is a tendency that mandibular width is broader than maxillary width and the width of male is broader than female. 2. There is no statistically significant sexual difference in Mx-Mn difference, Mx-Mn width differential, Mx/Mn ratio according to age and CVMI. 3. Mean of each measurement and 70% confidence interval of individual measurement according to age and sex were assessed and graphs were made for maxillary width, mandibular width, Mx-Mn difference, Mx/Mn ratio. 4. The width of maxilla and mandible in Korean children are broader than Western children during growth period.

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