• Imaging Science in Dentistry
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• 제48권1호
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• pp.11-19
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• 2018

Purpose: This study compared the diagnostic accuracy of cone-beam computed tomography (CBCT) scans obtained with 2 CBCT systems with high- and low-resolution modes for the detection of root perforations in endodontically treated mandibular molars. Materials and Methods: The root canals of 72 mandibular molars were cleaned and shaped. Perforations measuring 0.2, 0.3, and 0.4 mm in diameter were created at the furcation area of 48 roots, simulating strip perforations, or on the external surfaces of 48 roots, simulating root perforations. Forty-eight roots remained intact(control group). The roots were filled using gutta-percha (Gapadent, Tianjin, China) and AH26 sealer (Dentsply Maillefer, Ballaigues, Switzerland). The CBCT scans were obtained using the NewTom 3G (QR srl, Verona, Italy) and Cranex 3D (Soredex, Helsinki, Finland) CBCT systems in high- and low-resolution modes, and were evaluated by 2 observers. The chi-square test was used to assess the nominal variables. Results: In strip perforations, the accuracies of low- and high-resolution modes were 75% and 83% for NewTom 3G and 67% and 69% for Cranex 3D. In root perforations, the accuracies of low- and high-resolution modes were 79% and 83% for NewTom 3G and was 56% and 73% for Cranex 3D. Conclusion: The accuracy of the 2 CBCT systems was different for the detection of strip and root perforations. The Cranex 3D had non-significantly higher accuracy than the NewTom 3G. In both scanners, the high-resolution mode yielded significantly higher accuracy than the low-resolution mode. The diagnostic accuracy of CBCT scans was not affected by the perforation diameter.

• 농업생명과학연구
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• 제46권2호
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• pp.19-25
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• 2012

본 연구는 차광처리에 의한 잔대의 지상부 및 지하부 생장특성을 파악하여 잔대의 임간재배기술을 확립하기 위한 기초정보를 제공하기 위함에 있다. 차광처리에 의한 잔대의 발순율 및 개엽율은 25% 처리구에서 가장 높았으며, 75% 처리구에서 가장 낮게 나타났다. 잔대의 지상부 및 지하부의 생장특성을 분석한 결과, 초장, 엽수, 엽장, 엽폭 등 지상부의 생장은 25% 처리구에서 가장 우수하였고, 뿌리의 형태적 특성인 총근장과 뿌리투영면적은 25% 처리구에서 가장 높게 나타났으며, 뿌리표면적, 뿌리부피 및 뿌리직경은 대조구에서 가장 우수한 것으로 나타났다. 0.5 mm이하의 미세근은 75% 처리구에서 72.4%로 가장 높았으며 이어 25% 처리구에서 69.5%로 다른 처리구에 비해 높은 것으로 분석되었다.

• Plant Resources
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• 제2권2호
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• pp.65-68
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• 1999

This study was conducted to obtain the basic breeding information of Colocasia esculenta Schott. Effect of supplemental plant growth regulators and genotype difference were investigated on dormant bud tissue for proliferation. The plant regeneration ratio, plant height and root length were the best upon mixed treatment of 0.8mg/L IAA and 2.0mg/L zeatin. Both leaf weight and root weight were heavy upon culture in a dark condition. The leaf and root weights were heaviest in 6Pie sucrose concentrations. In several collected area the heaviest one was Binnangxin and then in the order of Suwon, Wanju and Puan. Genotype differences of tuber diameter and tuber weight were found in Suwon. Tuber weight was found in the order of Suwon (862mg) >Wanju(723mg) >Puan(649mg) >Binnangxin (424mg).

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2000년도 춘계임시총회 및 학술발표대회
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• pp.34-37
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• 2000

To determine the optimum planting density in Alisma plantago in the southern areas of Korea, Alisma plantago local cultivar was grown under different planting density. The plant height, number of stems and diameter of root were 30cm, 12 and 3.4mm respectively on the planting density, row 20cm $\times$ intrarow 35cm. The fresh yield of root and dry yield of root were 261.2Kg110a, 211.5Kg/10a respectively on the planting density, row 20cm x intrarow 35cm. Therefore, the proper planting density for high yield bumper crop of Alisma plantago for exporting to Japan is planting density with row 20cm $\times$ intrarow 35cm.

• Journal of Forest and Environmental Science
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• 제34권2호
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• pp.119-125
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• 2018

The tropical forests in developing countries are faced with the problem of illegal exploitation of trees. However, dearth of empirical means of expressing the dimensions, structure, quality and quantity of a removed tree has imped conviction of offenders. This study aimed at developing a model that can effectively estimate individual tree basal area (BA) from stump diameter (Ds) for Tectona grandis stands in Omo Forest Reserve, Nigeria, for timber valuation in case of illegal felling. Thirty-six $25m{\times}25m$ temporary sample plots (TSPs) were laid randomly in six age strata; 26, 23, 22, 16, 14, and 12 years specifically. BA, Ds and diameter at breast height were measured in all living T. grandis trees within the 36 TSPs. Least square method was used to convert the counted stumps into harvested stem cross-sectional areas. Six basal area models were fitted and evaluated. The BA-Ds relationship was best described by power model which gave least values of Root mean square error (0.0048), prediction error sum of squares (0.0325) and Akaike information criterion (-15391) with a high adjusted coefficient of determination (0.921). This study revealed that basal area estimation was realistic even when the only information available was stump diameter. The power model was validated using independent data obtained from additional plots and was found to be appropriate for estimating the basal area of Tectona grandis stands in Omo Forest Reserve, Nigeria.

• Journal of Chest Surgery
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• 제21권6호
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• pp.984-989
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• 1988

2-D echocardiographic examination of the aortic root diameter was known to be useful in the selection of the size of the prosthetic valve. Valve-patient mismatch was occasionally a serious problem after valve replacement, especially in aortic valve disease. Preoperative knowledge of the patient`s valve annulus size is therefore of great importance in the surgical management of these patients. So the relationship between preoperative 2-D echocardiographic diameter of the annulus size and replaced prosthetic valve were evaluated. 13 patients were analyzed in this study. 2-D echocardiographic measurements of aortic annulus diameter, as determined from the parasternal long axis view and apical four chamber view, demonstrated a high correlation with actual prosthetic valve size implanted at surgery[r=0.86, p< 0.001, SEE=1.08].

• 한국안전학회지
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• 제38권4호
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• pp.1-7
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• 2023

The steel wheels of urban railway vehicles gather a lot of data through regular measurements during maintenance. However, limited research has been carried out utilizing this data, resulting in difficulties predicting the maintenance period. This paper studied a machine learning model suitable for mileage prediction by studying the characteristics of mileage change according to diameter and flange thickness changes. The results of this study indicate that the larger the diameter, the longer the travel distance, and the longest flange thickness is at 30 mm, which gradually shortened at other times. As a result of research on the machine learning prediction model, it was confirmed that the random forest model is the optimal model with a high coefficient of determination and a low root mean square error.

• 한국약용작물학회지
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• 제6권2호
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• pp.137-141
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• 1998

쇠무릎의 적정(適正) 재식밀도(栽植密度)가 생육(生育) 및 수량(收量)에 미치는 영향을 구명(究明)하고자 나주(羅州) 자생수집종(自生蒐集種)을 공시하여 90cm 두둑에 재식밀도(栽植密度)를 조간(條間) 20cm, 25cm, 30cm의 3수준(水準)과 주간(株間) 5cm 7cm, 9cm의, 3수준(水準)으로 처리(處理)하고 시비량(施肥量)을 10a당(當) 실소(室素) 6kg, 인산(燐酸)14kg, 가리(加里)8kg 및 퇴비(堆肥) 1,500kg을 시용(施用) 후(後) 4월(月) 15일(日)에 $4{\sim}5$입(粒)씩 점파(点播)하여 양질(良質)의 생약(生藥) 생산(生産) 및 안정적(安定的)인 재배법(栽培法) 확립(確立)하고자 시험(試驗)한 결과를 요약(要約)하면 다음과 같다. 1. 토양의 화학성(化學性)은 시험후 토양이 시험전 토양에 비해 유기물(有機物), 유효인산(有效燐酸), 칼리, 칼슘, 마그네슘, C. E. C 함량이 증가되는 경향을 보였다. 2. $30{\times}9cm$의 소식(疎植) 재배구(栽培區)에서 경태(莖太)가 굵고 주당(株當) 분지수(分枝數) 및 지근수(枝根數)는 많았으나 $25{\times}5cm$(57, 140주(株)/10a) 구(區)에서 면적당 입모수(立毛數)가 많아 경장(莖長)이 길어지고 세근(細根)이 적어진 반면에 주근장(主根長)과 주근경(主根徑)이 커져 단위(單位) 면적당(面積當) 근수량(根收量)은 증가되었다. 3. 건근수량(乾根數量)은 $25{\times}5cm$ 구(區)에서 $25{\times}5cm$ (306kg/10a)의 밀식구(密植區)에 비하여 상근중(上根重) 비율(比率)이 71%로 높아지고 잔뿌리가 적어져 품질이 향상되어 71% 증수(增收)를 보였다. 4. $25{\times}5cm$ 밀식재배(密植栽培)에서 건근수량(乾根收量)은 경태(莖太), 주당(株當) 분지양(分枝數) 생경엽중(生莖葉重) 및 근수(根數)와는 부(負)의 상관(相關)을 보였으며 경태(莖太), 절수(節數), 주근장(主根長,. 주근경(主根徑) 및 북근중(北根重) 북(比) 율(率) 등(等)과는 정(正)의 상관(相關)이 인정되었다.

• Journal of Biosystems Engineering
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• 제42권3호
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• pp.227-233
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• 2017

Purpose: Morphological properties of soybean roots are important indicators of the vigor of the seed, which determines the survival rate of the seedlings grown. The current vigor test for soybean seeds is manual measurement with the human eye. This study describes an application of a machine vision technique for rapid measurement of soybean seed vigor to replace the time-consuming and labor-intensive conventional method. Methods: A CCD camera was used to obtain color images of seeds during germination. Image processing techniques were used to obtain root segmentation. The various morphological parameters, such as primary root length, total root length, total surface area, average diameter, and branching points of roots were calculated from a root skeleton image using a customized pixel-based image processing algorithm. Results: The measurement accuracy of the machine vision system ranged from 92.6% to 98.8%, with accuracies of 96.2% for primary root length and 96.4% for total root length, compared to manual measurement. The correlation coefficient for each measurement was 0.999 with a standard error of prediction of 1.16 mm for primary root length and 0.97 mm for total root length. Conclusions: The developed machine vision system showed good performance for the morphological measurement of soybean roots. This image analysis algorithm, combined with a simple color camera, can be used as an alternative to the conventional seed vigor test method.

• 생물환경조절학회지
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• 제14권4호
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• pp.239-244
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• 2005

본 연구는 시설양묘 용기에서 직근성 수종인 찰피나무 유묘의 생육상황 및 뿌리발달 형태를 탐구하기 위하여 5개월 간 플라스틱 온실에서 수행되었다. 공시용기로 사용된 플라스틱 망 용기와 일반 플라스틱 용기에서 생육한 용기묘의 수고생장 차이는 크지 않았으나, 근원경 생장은 플라스틱 망 용기에서 높게 나타났다. 플라스틱 망 용기는 묘목의 뿌리발달에 영향을 끼쳐 묘목의 뿌리발달을 촉진시켰으며, 전체 지하부의 건물생산량을 증가시켰다. 특히 플라스틱 망 용기묘에서는 적극적으로 유도된 공기단근에 의하여 나선형 뿌리가 나타나지 않았다. 따라서 본 실험에 사용된 플라스틱망 용기는 찰피나무 용기묘 생산에 유용하게 활용할 수 있을 것으로 판단되며, 이 용기에서 생산된 묘목은 다양한 식재지 환경에서 식재될 경우 활착율 증가는 물론 생장율 증가도 보일 것으로 생각된다.