• Journal of Forest and Environmental Science
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• 제39권2호
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• pp.96-104
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• 2023

The successful restoration program requires a comprehensive understanding of variables influencing seedling efficiency. Below-ground is hypothesized to have a major impact on seedling performance of species when planted in agriculture, and degraded areas with different types of mulching. This study investigated on Sg. Terla Forest Reserve in Cameron Highlands Pahang, Malaysia. In this study randomized complete block design (RCBD) was used. The excavation method was applied to study the root system development, above, and below ground biomass distributions under different types of mulching: coconut mulching (CM), oil palm mulching (OM), plastic mulching (PM) and control (CK). The root diameter, main root length, lateral root length, root coiling, and root direction toward to sun were recorded. The results in this study indicate that mulching had significant effect on root diameter, main root length, and root distributions among treatments while for lateral root length, root: shoot ratio, dry biomass distributions, and above and below ground biomass did not showed significant effect among treatments. The highest values for root diameter, lateral root length, main root length, root distributions, dry biomass distributions and above and below ground biomass were showed in CM treatments. However 75% of root coiling was observed in seedlings between treatments.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.303-303
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• 2022

The purpose of this study was to evaluate agronomic characteristics and identify the useful traits to utilize the wheat genetic resources for breeding programs by understanding the phenotypic variation among germplasm through multivariate analysis. In this study, a total of 394 wheat accessions were characterized for 15 agronomic traits using the National Agrobiodiversity Center (NAC) descriptor list, of which 31 accessions from 6 species and 363 unidentified accession (Triticum spp.) available at the NAC, Rural Development Administration (RDA), Korea. Growth characteristics such as leaf width, culm length, spike length, spikelet length, solid stemmed, days to heading, days to maturity, grain-filing period, and also seed characteristics such as width, height, area, perimeter, circle, solidity, and germination percent were studied. Among the 15 agronomic characteristics, the germination percent showed the smallest variation between resources (CV = 0.4%), and the spikelet length (CV = 66.5%) showed the highest variation. A strong positive correlation was found between seed traits such as seed height and seed area (r = 0.90), seed height and seed perimeter (r = 0.87) and seed length and width (r = 0.80). Principal component analysis (PCA) was conducted and the first five principal components comprised 76.7% of the total variance. Among the first five PCs, PCI accounted for 28.5% and PC2 for 20.0%. Wheat resources (394) were classified into four clusters based on cluster analysis, consisting of 215 resources(I), 117 resources(II), 48 resources(III), and 14 resources(IV). Among the clusters, the resources belonging to Cluster III showed the lowest seed width, height, area, and perimeter characteristics compared to other clusters. The wheat resources belonging to cluster IV had small seed width and low germination percent, but took longer to form heads and mature than resources in other clusters. These results will serve as the basis for further genetic diversity studies, and important agronomic characteristics will be used for improving wheat, including developing high-yielding and resistant varieties to biotic and abiotic stresses via breeding programs.

• 한국어병학회지
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• 제21권3호
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• pp.181-188
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• 2008

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay was used to detect and identify four fish viruses, fish iridovirus, viral hemorrhagic septicaemia virus (VHSV), viral nervous necrosis virus (VNNV), hirame rhabdovirus (HRV). Four viruses were detected by PCR with each specific primers. Identification of iridovirus was achieved by digesting the PCR amplified fragment with a restriction enzyme ApaⅠ. It was possible to distinguish positive from false positive PCR amplicons of VHSV by RFLP of PstⅠ or HindⅢ restriction enzymes. VNNV was identified using RFLP of BamHⅠrestriction enzyme and HRV was identified by XbaⅠ restriction enzyme. This approach can be used for more rapid, simple and specific diagnosis of fish viral diseases.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.110-111
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• 2019

In ACI 318-19 published recently, the conditions and development length equation to use the headed deformed bars were changed considerably. Although the use of the larger-diameter(No.14 and 18) headed deformed bars isn't yet permitted, the use of the high strength(80,000psi) headed deformed bars is permitted and the effect of bar-diameter($d_b$) on the development length is increased considerably. Therefore, structures using larger-diameter headed deformed bars will be expected to be affected by this code change. We will study the effect of the code change on the development design and find out the design optimization method to minimize the effect of the changed conditions and development length equation.

• 한국건축시공학회지
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• 제9권6호
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• pp.141-149
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• 2009

본 연구에서는 GFRP 하부근과 상부근의 정착길이 설계식을 제안하기 위하여 실험적 연구를 수행하고 실험결과의 통계적 분석을 실시하였다. 상부근과 하부근 각각 52개의 수정인발실험을 계획하였으며, 실험변수는 보강근의 묻힘길이(보강근 지름의 15, 30, 45배), 순피복두께(보강근 지름의 0.5-2.0배), 상부근 효과, 보강근 종류(국내산 2종, 국외산 1종 등 3종) 및 보강근지름(D10, D13, D16)이다. 하부근과 하부근 각각에 대하여 수정인발실험을 통하여 평균부착강도를 결정하고, 평균부착강도에 대한 2변수 선형회귀분석을 실시하였다. 2변수 선형 회귀분석의 결과에 대하여 5% 분위수를 적용하여 보수적인 방법으로 정착길이 설계식을 제안하였다. 2변수 선형 회귀분석에 의한 하부근과 하부근의 정착길이 설계식을 제안하고 상부근과 하부근의 정착식을 비교하고, ACI 440.1R-06 식과 비교하였다.

• 대한토목학회논문집
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• 제30권5A호
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• pp.485-493
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• 2010

국내에서 개발된 이형 GFRP 보강근은 표면에 구축된 이형의 전단강도가 콘크리트의 전단강도 보다 상대적으로 작아 이형철근과 달리 이형 자체가 전단파괴되는 파괴모드를 보이는 것으로 확인된바 있다. 본 논문에서는 이형을 갖는 GFRP 보강근의 기본정착길이를 인발실험과 설계모델식과 해석적 엄밀식을 통해 고찰하였다. 실험결과, 동일조건하에서 파괴모드가 변화되는 임계정착길이가 이형철근은 직경의 15배, 이형 GFRP 보강근은 20배인 것으로 나타났다. 또한 실험결과를 ACI440.1R-03 설계모델식에 적용하여 분석한 결과, 충분한 횡구속이 수반된 경우 직경 9 mm의 이형 GFRP 보강근의 기본정착길이는 직경의 21배인 것으로 나타났다. 반면, ACI440.1R-06에 제시된 기본정착길이 모델은 실험결과에 비하여 너무 과대한 기본정착길이를 요구하는 것으로 나타났다. Cosenza 등(2002)의 모델은 실험결과에 비하여 더 적은 기본 정착길이를 요구하므로, 설계목적의 사용은 제한적인 것으로 판단되었다.

• 한국어류학회지
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• 제20권4호
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• pp.285-290
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• 2008

넙치 암컷과 강도다리 수컷을 인공교배하여 만든 잡종의 형태적 특징을 조사하였다. 잡종은 두 종의 중간 형태를 나타내지만 대부분의 형질이 수컷인 강도다리에 조금 더 가까웠다. 잡종은 체장에 대한 체고 비율이 56.3%로서 체고가 높고, 두장에 대한 문장 비율 20.6%, 두장에 대한 상악장 비율 34.2%이었으며, 체장에 대해 전배기장 10.5%, 전흉기장 32.2%, 전복기장 29.8%, 전둔기장 28.0%로서 강도다리 체형에 다소 가까웠다. 눈이 있는 쪽은 암황록색 바탕에 옅은 검은 얼룩이 흩어져 있으며, 강도다리 체측에 산재해 있는 작은 골판은 없다. 등지느러미에 6~20개, 뒷지느러미에 5~10개의 가로띠무늬가 있으나 가장자리로 갈수록 흐려져 불명료해진다. 지느러미 기조수는 등지느러미 60~66, 뒷지느러미 40~51, 꼬리지느러미 18~21, 가슴지느러미 11~12개였으며, 아가미의 새파수 13~18, 새사수 73~98개였다. 척추골수는 34~37개였으며, 미추골 시작부위에서 척추골 2~3개가 융합된 개체가 많았다.

• 한국철도학회지
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• 제4권1호
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• pp.9-15
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• 2001

The railways in Russia is a core of the industrial, trade and technological development. They changed the country for the best affecting all sides of its life. The total length of the railways in Russia is 87,500 km (7％ of the World railway network). They account for about a 25％ of the World freight and 15% of the passenger traffic. In terms of length of electrified railways Russia is a World leader and in terms of total length of tracks it is second after the USA. Annual freight turnover is the third after the USA and China. (omitted)

• 한국의류학회지
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• 제34권3호
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• pp.480-491
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• 2010

This study investigates the body satisfaction and fitness apparel depending on age and silhouette. The subjects were 254 females 20~50 years of age living in Chungju South Korea. There are various body types in women over the age of 35, the lower part of the body-development type, regular type, the upper part of the body-development type, and the rectangular body type. In addition, there is a lower satisfaction level in circumferences related with apparel fit, especially in the sleeve length, armhole, and crotch length. Therefore, a size system is needed that considers various body types in ready-to-wear clothing for middle-aged women. Design, color, and pattern are most important in clothing purchases by unmarried women, but the ease of laundry management and price discounts are the most significant for clothing purchases by married women. The upper part of the body-development type is unsatisfactory in the size-fit of sleeve length and shoulder width, but the lower part of the body-development type is unsatisfactory in the circumference of the waist, hip, abdominal, girth of skirt, and crotch length. The rectangular body type and the lower part of the body-development type are unsatisfactory in movement comfort, especially in hip girth and crotch length. The upper part of the body-development type is unsatisfactory in the movement comfort of the chest and elbow girth.

• International Journal of Automotive Technology
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• 제2권3호
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• pp.103-107
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• 2001

Many researches on pressure-swirl injectors due to the variety of application have been conducted on the effects of nozzle design, operating conditions, properties of liquid and ambient conditions on the flow and spray characteristics. The breakup length of conical emulsified fuel sheet resulting from pressure-swirl atomizer using in the oil burner was investigated with the digital image processing method with neat light oil and emulsion with water content of lotto% and the surfactant content of 1-3%. The injection pressure ranged from 0.1 to 1.2 MPa was selected. The various regimes for the stage of spray development within the experimental conditions selected in this study is newly suggested in terms of Ohnesorge number and injection pressure. The breakup length for both criteria show the same tendency even though the random nature of perforation and disintegration process of liquid sheet. The stage of spray development is widely different with the physical properties of liquid atomized, mainly viscosity of liquid. The breakup length decreases smoothly with increase in the injection pressure for the lower viscous liquid.