• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.792-801
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• 1996

A thinning algorithm -based image analysis technique was developed to measure corn root lengths. The root length measurement method was evaluated by comparing thread lengths measured by the image analysis system with actual thread lengths. The length measurement method accurately estimated actual thread lengths (less than 2% calculated error). Also, a rapid root length density measurement procedure, which utilizes the above root length measurement method, was developed to estimate corn root length density without washing the roots. Root length densities estimated from the cut soil surface of core samples taken from the field were paired with the root length densities determined from washed roots from the same soil core sample. A linear relationship between these two values was expected and was found. Eliminating the root washing procedure reduces the time required for measuring corn root length density substantially.

• 대한치과교정학회지
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• 제47권1호
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• pp.39-49
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• 2017

Objective: This retrospective, cross-sectional study aimed to establish reference data for normal crown and root lengths and the root-crown ratios (R/C ratios) for the mature maxillary and mandibular incisors in a Korean population by using cone-beam computed tomography (CBCT). Methods: We included 672 Korean patients (141 men and 531 women; mean age, $27.2{\pm}7.7years$) who underwent CBCT examinations during various dental treatments. Crown and root lengths and the R/C ratios of the maxillary and mandibular incisors were measured using CBCT data, which were analyzed to detect significant differences between demographic factors as well as sagittal and vertical skeletal or occlusal relationships. Results: Teeth of the same type in each half-arch were symmetrical. The mean R/C ratios varied from 1.1 to 1.2 for the maxillary incisors and from 1.3 to 1.4 for the mandibular incisors. Crown and root lengths were greater in men than in women, regardless of tooth type. Root lengths and R/C ratios for the mandibular incisors were significantly greater in patients with skeletal Class II malocclusion or an excessive overjet than in the other patients. The R/C ratios for the mandibular incisors were lower in patients with an open bite than in those with a normal or deep bite. Moreover, the R/C ratios for the mandibular incisors increased with age. Conclusions: The data obtained in our study can serve as reference values for crown and root lengths and the R/C ratios for the maxillary and mandibular incisors in the Korean population.

• Restorative Dentistry and Endodontics
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• 제23권1호
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• pp.339-345
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• 1998

The purpose of this study was to evaluate the in vitro accuracy of Root ZX(Morita Co., Japan) which is the ratio type electronic apex locator. The 86 extracted human palatal roots of maxillary molar with fully formed apices were used. File lengths with the file tip just visible at the foramen were compared to those measured with Root ZX. For length measuring with Root ZX, saline test model with which the apical 1/3 of each root was submerged into normal saline were designed. The root canal lengths were determined with Root ZX and the radiographs were taken with a file in the canal. The distances from file tips of Root ZX lengths to apecies in radiographs also were measured with Profile projector PJ311(Mitutoyo Co., Japan). The results were as follows : 1. The root canal length determined with electronic apex locator was $0.78{\pm}0.53mm$ shorter than the length with visual measurement. 2. The file tip of Root ZX lengths was located at $0.85{\pm}0.49mm$ away from the apex in radiograph. 3. The accuracy of the Root ZX was 79.1% within 0.5mm of visual working length and 96.5% within 1.0mm.

• 대한치과교정학회지
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• 제43권6호
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• pp.271-278
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• 2013

Objective: The purposes of this study were to determine the accuracy of crown and root length measurements of premolars using cone-beam computed tomography (CBCT) and to generate reference CBCT-based data on incisor, canine, and premolar lengths in patients with malocclusions. Methods: Imaging was performed using a CBCT scanner with a 0.292-mm voxel size and 12-bit grayscale. The CBCT-based length measurements were compared with direct measurements of 94 subsequently extracted premolars without metal restorations using the paired t-test. Furthermore, the crown and root lengths of incisors, canines, and premolars in 62 Korean patients with malocclusions were measured using CBCT, and Pearson's correlation coefficients were calculated to examine the relationship between the crown and root length measurements of each tooth type. Results: The differences between the CBCT-based and direct measurements of the extracted premolars were not significant, with 95% limits of agreement of -0.90 to 0.90 mm for crown length and -1.23 to 1.18 mm for root length. Weak positive correlations between the crown and root length measurements were observed for the mandibular canine and premolars. Conclusions: The CBCT-based measurements showed a wider range of limits of agreements for root length than for crown length. The CBCT-based data can be used as a reference for evaluating root length and resorption of teeth without metal restorations in patients with malocclusions.

• Restorative Dentistry and Endodontics
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• 제23권2호
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• pp.670-675
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• 1998

Recently electronic apex locators have been used widely in root canal treatment, but, accuracy of electronic apex locators is controversial. The purpose of this study was to evaluate the accuracy of Apex Finder A.F.A(EIE Analytic Technology, U.S.A.) in vivo compared with Root-Zx and radiograph. The root canal lengths were determined with Root-Zx(32 tooth) in before pulp extirpation and after pulp extirpation. Then the radiographs were taken with a file in the canal. The root canal lengths were determined with Apex Finder A.F.A.(21 tooth) in before pulp extirpation and after pulp extirpation and under NaOCl. Then the radiographs were taken with a file in the canal. The results were as follows: 1. There was no significant statistical difference in Root-Zx between before pulp extirpation and after pulp extirpation(p > 0.05). 2. There was no significant statistical difference in Apex Finder A.F.A. between before pulp extirpation and after pulp extirpation(p > 0.05). But, there was significant statistical difference under NaOCl(p < 0.05). 3. There was no significant statistical difference in accuracy between Root-Zx and Apex Finder A.F.A.

• Restorative Dentistry and Endodontics
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• 제37권3호
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• pp.149-154
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• 2012

Objectives: To evaluate the accuracy of the Root ZX in teeth with simulated root perforation in the presence of gel or liquid type endodontic irrigants, such as saline, 5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine liquid, 2% chlorhexidine gel, and RC-Prep, and also to determine the electrical conductivities of these endodontic irrigants. Materials and Methods: A root perforation was simulated on twenty freshly extracted teeth by means of a small perforation made on the proximal surface of the root at 4 mm from the anatomic apex. Root ZX was used to locate root perforation and measure the electronic working lengths. The results obtained were compared with the actual working length (AWL) and the actual location of perforations (AP), allowing tolerances of 0.5 or 1.0 mm. Measurements within these limits were considered as acceptable. Chi-square test or the Fisher's exact test was used to evaluate significance. Electrical conductivities of each irrigant were also measured with an electrical conductivity tester. Results: The accuracies of the Root ZX in perforated teeth were significantly different between liquid types (saline, NaOCl) and gel types (chlorhexidine gel, RC-Prep). The accuracies of electronic working lengths in perforated teeth were higher in gel types than in liquid types. The accuracy in locating root perforation was higher in liquid types than gel types. 5.25% NaOCl had the highest electrical conductivity, whereas 2% chlorhexidine gel and RC-Prep gel had the lowest electrical conductivities among the five irrigants. Conclusions: Different canal irrigants with different electrical conductivities may affect the accuracy of the Root ZX in perforated teeth.

• 한국작물학회지
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• 제39권2호
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• pp.115-120
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• 1994

다양한 용도에 적합한 양질품종을 육성하기 위하여 찰성 및 과성인자가 도입된 계통들이 육성, 보급단계에 이르고 있다. 이들 인자를 도입함에 따라 흡수성, 퍼짐성이 좋아지고 호화개시온도, 호화시간이 짧아졌으며 쌀보리의 재배지대 북상에 문제가 되던 내한성도 해결되었다. 그러나 찰성인자가 흡수성이 빠른 점과 쌀보리의 종피가 과실과 분리되어 수분을 보지하는 시간이 길어짐에 따라 찰 쌀보리는 수발아의 위험성은 더욱 커지게 되었다. 보리 수확시기에 수발아는 품종육성 및 재배, 이용면에서 대단히 중요한 재해이다. 본 시험에서 수발아정도에 따른 수량의 감소와 품질변화 및 수발아된 종자를 종자로 이용시 재발아정도를 조사하여 얻은 몇가지 결과는 다음과 같다 1. 발아된 종자의 재발아율은 발근장 2mm시 68%, 4mm에서 49%이었으나 그이상에서는 급격히 낮아졌으며, PI는 대조구에 비해 발근장 2mm 에서도 큰 차이를 보였다. 2. 발근정도에 따른 수량감소율은 발근장이 길어지면 커지는 경향이었고, 3. 발근장이 길어지면 쌀보리 72%, 겉보리 64%로 도정하는 정맥시간이 짧아졌으며, 4. 발근정도에 따른 도정후 완전입율은 대조구(2시간 침적)에서 98∼96.5%이나 발근장 14mm 에서는 64∼82.4%로 크게 저하되었으며, 5. 도정된 보리쌀의 백도는 무처리구보다도 침적2시간 및 발근장 2mm처리에서 높았으나 발근장이 길어짐에 따라 점차 낮아졌다 6. 발근장이 길어짐에 따라 Sedimentation value는 점차 낮아졌다.

• 한국잡초학회지
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• 제12권2호
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• pp.173-182
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• 1992

해바라기의 상대억제작용(相對抑制作用)(타감작용(他感作用), Allelopathy) 및 천연제초제(天然除草劑)로서의 개발가능성(開發可能性)에 관한 시험(試驗)을 1988-1991년(年)에 걸쳐 국제미작연구소(國際米作硏究所) 농학(農學), 생화학부(生化學部) 및 국립(國立)필리핀 대학교(大學校) 화학과(化學科) 천연물(天然物) 연구실(硏究室)에서 수행(遂行)하여 얻은 결과중(結果中) 상대억제작용성(相對抑制作用性) 해바라기 근분비물질(根分泌物質)의 생물검정(生物檢定) 및 상대억제작용물질(相對抑制作用物質)(Allelochemicals)의 HPLC 분석결과(分析結果)는 다음과 같다. 1. 해바라기 근분비물질(根分泌物質)의 산(酸) 및 중성분획물질(中性分劃物質)을 생물검정재료(生物檢定材料)로 사용한 피 (Echinochloa colona (L.) Link 및 무 (Raphanus sativus L.)의 발아(發芽)가 유의성(有意性)있는 억제(抑制)를 보인 반면 알칼리 및 수용성분획(水溶性分劃)에서는 억제작용(抑制作用)이 나타나지 않았다. 2. 피의 경우 해 바라기 근분비물질(根分泌物質)의 분획물질(分劃物質) $10{\mu}l$ 농도(濃度)에서부터 유의적(有意的)인 생장억제(生長抑制)가 인정(認定)되었으며 지상부(地上部) 신장억제(伸張抑制)보다 지하부(地下部) 신장억제(伸張抑制)가 산(酸) 및 중성분획(中性分劃)에서 더 강하게 나타났다. 3 무의 경우 농도(濃度)에 관계없이 지상(地上) 및 지하부(地下部) 신장억제(伸張抑制)가 산(酸) 및 중성분획(中性分劃)에서 각각 높게 나타났다. 4. 생물검정(生物檢定)에서 강한 상대억제작용(相對抑制作用)을 보인 산성분획물질(酸性分劃物質)의 HPLC분석결과(分析結果) hydroquinone, ${\beta}$-resorcyclic acid, vanillic acid, caffeic acid, salicylic acid, quercetin 등의 물질(物質)이 확인(確認)되었다. 한편, 중성분획물질(中性分劃物質)에서는 Hydroquinone, gentisic acid, ${\beta}$-resorcyclic acid, vanillic acid, caffeic acid, ferulic acid, quercetin 등이 각각 동정(同定)되었다.

• 한국토양동물학회지
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• 제8권1_2호
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• pp.23-26
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• 2003

고구마뿌리혹선충(Meloidogyne incognita)에 대하여 멀구슬나무(Azadirachta indica) 부산물인 Suneem-G와 요소의 억제효과를 연구하였다. 폿트 당 살균토양을 2kg씩 넣고 M. incognita 2령기 유충 2,000마리를 접종한 후 오크라를 심고 Suneem-G를 처리하였다. Suneem-G의 처리량에 따라 유충 밀도 및 형성은 유의성 있게 차이가 있었고, Suneem-G와 요소를 동시에 처리하였을 때 그 효과는 상승하였으며, 선충 밀도가 낮을수록 오크라 식물체의 생장이 좋았다. 요소와 Suneem-G를 함께 처리한 조합에서 가장 높은 효과를 보였으며, 처리량의 증가에 따라 억제 효과도 증가하였다. 폿트 당 Sueem-G 6g과 요소 25g 조합의 처리에서 최대의 식물생육과 뿌리혹의 최대감소를 보였는데, 식물체 엽육과 뿌리의 길이가 84%와 58%나 높았으며, 뿌리혹은 58%나 감소하였다. Suneem-G의 최저 처리인 폿트 당 2g 처리에서 식물체의 엽육과 뿌리의 길이는 25.7과 17%까지 증가하였으며, 뿌리혹은 24% 감소하였다. 그러나, 요소 25g 처리에서 가장 낮은 효과를 나타내었으며, 식물의 엽육과 뿌리의 길이는 증가하였으며 뿌리혹은 14% 감소하였다.

• 한국약용작물학회지
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• 제23권5호
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• pp.363-369
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• 2015

Background : Platycodon grandiflorum radix used as a therapeutic agent for lung and respiratory diseases in traditional Korean medicine. The saponin and sugar content in P. grandiflorum root is dependent on the drying temperature and method. In this study, we investigated saponins and antioxidant contents in dried P. grandiflorum roots either not cut or cut to different lengths. Methods and Results : P. grandiflorum roots were either cut to 0.5, 1.0 or 2.0 cm in length or left uncut. They were dried at $45^{\circ}C$ and the effect of antioxidant substances, antioxidant ability, and saponin content were investigated. P. grandiflorum roots rapidly dried out when cut to short lengths. The saponin contents (platycodin D, polygalacin D, and deapioplatycodin D) was highest in the uncut P. grandiflorum roots. When the cut lengths were long, the levels of polyphenolic compound increased. However, 2,2'-azinobis-3-ethylbenzo-thiazoline-6-sulfonic acid (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities were higher in the samples cut to shorter lengths. Conclusions : These results suggested that the saponin and antioxidant content of P. grandiflorum roots could be maximized by controlling the drying rate of the roots via adjustments to the root cutting length.