• Journal of Welding and Joining
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• 제13권4호
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• pp.75-84
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• 1995

In GMA welding of sheet metal, the short circuit metal transfer mdoe is preferred because of its low heat input and capability of bridging the root gap. The molten electrode is transferred to the workpiece during repectitive short circuit in the model. The waveform of welding current or voltage and the frequency of short circuiting are affected by a number of factors including: magnitude of welding current and voltage, root gap, electrode extension, power supply characteristics, and so on. In this study experimental models were proposed, which are able to determine the relationship between the root gap and short circuit frequency and the relationship between the root gap and appropriate welding speed that produces the good quality of back bead without burn through. Using the experimental models, the root gap can be obtained from measuring the short circuit frequency, and then the appropriate weldig speed to the root gap can be determined. Thus a back bead control system was constructed by controlling the welding speed for maintaining the quality of back bead. The developed system has shown the successful capability of back bead control.

• 대한소아치과학회지
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• 제42권4호
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• pp.319-326
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• 2015

Short root anomaly (SRA)는 매우 드문 질환으로, 교정력에 의한 치근흡수에 있어서 정상적인 치아보다 더 취약하므로 처치시에 어려움이 있다. 또한, 혼합치열기 시기에 나타나는 전반적인 SRA의 경우는 진단 또한 쉽지 않다. 초기 혼합치열기환아에서 방사선 사진만으로 전반적인 SRA를 예측하기 어렵지만, 가족력이나 관련 전신질환, 또는 구강 내 다른 치아이상(tooth anomaly) 등의 요소가 있는 경우, SRA를 염두에 두어야 한다. 본 증례는 전악에 걸쳐SRA를 보이는 초기 혼합치열기 환아의 교정적 처치를 다루었다. 비록 국소적인 치아 상실이 있었으나 적절한 교정적 배열을 통해 더 이상의 과도한 치근흡수 없이 치료를 마무리 하였으며, 비교적 양호한 치료 결과를 얻었기에 이를 보고하고자 한다. 결론적으로, SRA 환자에서도 교정 치료가 가능하며, SRA가 예측되는 혼합치열기 환아에서 치근 흡수나 치아상실과 같은 합병증이 나타나지 않도록 특히 주의를 기울여야 한다.

• 한국임상수의학회지
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• 제17권1호
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• pp.187-193
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• 2000

Fifteen adult Korea Jin-do dogs were studied by echocardiography to obtain the basic data of the imaging planes and normal references ranges to the aorta and pulmonary artery internal dimension. Measurements of aortic root internal dimension(AOID) and right pulmonary artery internal dimension (RPAID) were made at modified pulmonary arteries level short-axis view and left ventricular outflow tract long-axis view. The aortic root internal dimension and right pulmonary artery internal dimension at modified pulmonary arteries level short-axis view were 18.7$\pm$1.3mm (mean$\pm$SD) and 10.1$\pm$0.8mm, respectively. And RPAID/AOID was 0.5$\pm$0.1mm. The aortic root internal dimension and right pulmonary artery internal dimension at left ventricular outflow tract long-axis view were 19.3$\pm$1.6 mm and 10.7$\pm$1.3mm, respectively. And RPAID/AOID was 0.5$\pm$0.1mm. These results indicate that modified pulmonary arteries level short-axis view is useful planes to examine the aortic root and pulmonary arteries, and aortic root internal dimension is significantly higher(40~50%)than the right pulmonary artery internal dimension. Therefore measurements of aortic root internal and right pulmonary artery internal dimension can be used for monitoring dilation of pulmonary artery.

• 대한소아치과학회지
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• 제48권1호
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• pp.122-128
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• 2021

Short root anomaly는 비정상적으로 짧고 뭉툭한 치근 형태를 가진 드문 질환이다. 대부분 상악 중절치에 대칭적으로 나타나며 영구치에서만 관찰되어 왔다. 이 증례는 9세 여환으로 혼합치열기에 짧은 치근 발달을 주소로 개인병원에서 의뢰되었다. 방사선 사진 및 구강 내 검사에서 법랑질 저형성증과 치내치와 같은 다른 치아이상과 함께 상악 및 하악 전치부와 하악 제 1대구치에서 SRA가 관찰되었다. 5년동안의 장기추적 관찰을 통해 환아의 모든 치아들은 혼합치열기에서 영구치열기로 변화하였고 모든 영구치에서 전반적인 SRA가 관찰되었다. 교정적 진단을 위해 촬영된 측면 두부 방사선 사진에서 치아 이상과 밀접한 관련이 있는 것으로 보고된 전방과 후방 상돌기 사이의 석회화인 sella turcica bridge 또한 관찰되었다. 이러한 여러 요소들을 통하여 치근 흡수나 치아 상실의 예방과 성공적인 관리 위해 SRA를 조기 진단하는 것은 매우 중요하다. 이 증례 보고에서는 다른 치아이상과 sella turcica bridge와 함께 전악에 걸쳐 나타난 전반적인 SRA를 보이는 환아를 장기적으로 관찰하고 의미있는 결과를 나타내고 있기에 이를 보고하는 바이다.

• Journal of Plant Biology
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• 제34권4호
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• pp.311-316
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• 1991

The origin of cambial initials from procambium was studied in the seedling root of Acer saccharinum. In transverse view, the first periclinal divisions of procambial cells occurred just outside of each early metaxylem and resulted in meristematic strips. As root development progressed, the division activities appeared subsequently outside of each late metaxylem and then in pericycle cells opposite the four protoxylem poles. Eventually, such meristematic strips were connected completely each other. Thus, a nearly rectangular shaped meristematic layer in outline was formed outside the xylem in a whole root transectioned. In tangential section, early procambium showed a homogeneous structure consisted of uniform short cells with transverse end walls. However, some of the procambial cells did elongate, whereas others divided transversely. The former become more elongate, tapered, and vacuolated. Finally, they differentiated into fusiform initials. Short cells consisting axial strands divided continuousely in transverse plane and became ray initials, while some short cells elongated and transformed into long cells. The early ontogeny of vascular cambium in Acer saccharinum root was interpreted to be established by a gradual process.

• 자연과학논문집
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• 제6권1호
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• pp.55-64
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• 1993

본 연구는 Aloe vera의 흡지번식에 있어서 auxin류의 처리와 몇 가지 재배요인이 발근에 미치는 영향을 실험한 바 다음과 같은 결과를 얻었다.1. 흡지의 크기와 근경의 유무에 따른 발근효과를 보면 단흡지(15-20cm)는 근 경을 제거한 것 보다 부착했을때 발근수가 많았고, 장흡지(25-30cm)는 근경을 제거했을때 근수 및 근건물중이 높은 경향을 나타냈다. 한편 단흡지는 근경이 부착되었을때 IBA 500mg/I처리에서 가장 높은 발근효과를 나타냈고, 장흡지는 근경을 제거했을때 IBA 1,000mg/I와 NAA 200mg/I처리에서 가장 촉진적이다.2. IBA, NAA, ethychlozate의 침지시간에 따른 무근경흡지의 발근양상을 보면 IBA와 NAA가 발근에 촉진적으로 작용했으나 NAA와 ethychlozate처리구에서는 약해를 받은 흔적이 나타나 aloe의 발근촉진에는 IBA가 가장 적합한 물질로 판단되었다. 또한 단흡지는 IBA 500mg/I에 10분 침지한 것이, 장흡지는 IBA 1,000mg/I에 10분 침지한 것이 근수, 최근장, 근중 및 발근율에서 가장 효과적 이었다. 그리고 흡지의 크기에 따른 발근효과는 장흡지가 더욱 촉진적이었고 균일한 발근양상을 나타냈다.3. 무근경장흡지의 근수와 근중은 IBA 1,000mg/I처리에 7일간 음건했을때 가장 높은 효과를 나타냈다. 그리고 IBA를 처리하지 않았을 때에는 음건이 길어수록 근장이 길어지는 경향을 보였다.4. Aloe흡지삽에 있어서 삽목용토에 따른 발근효과를 보면 인공용토 보다는 퇴비가 많이 함유된 재배토양에서 뿌리분화 및 뿌리생육이 가장 좋은 효과를 나타냈다.5. Aloe흡지삽의 발근은 투광율이 높을수록 양호한 경향을 보였고, 피복재료에 있어 서는 투명비닐 보다 흑색비닐이 발근을 더욱 촉진시켰다.

• Imaging Science in Dentistry
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• 제42권3호
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• pp.129-137
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• 2012

Purpose: To compare different radiographic methods for assessing endodontically treated teeth. Materials and Methods: Root canal treatments were applied in 120 extracted mandibular teeth, which were divided into four groups: (1) ideal root canal treatment (60 teeth), (2) insufficient lateral condensation (20 teeth), (3) root canals filled short of the apex (20 teeth), (4) overfilled root canal treatment (20 teeth). The teeth were imaged using intraoral film, panoramic film, digital intraoral systems (CCD and PSP), CCD obtained with portable X-ray source, digital panoramic, and CBCT images obtained at 0.3 $mm^3$ and 0.2 $mm^3$ voxel size. Images were evaluated separately by three observers, twice. Kappa coefficients were calculated. The percentage of correct readings obtained from each modality was calculated and compared using a t-test (p<0.05). Results: The intra-observer kappa for each observer ranged between 0.327 and 0.849. The inter-observer kappa for each observer for both readings ranged between 0.312 and 0.749. For the ideal root canal treatment group, CBCT with 0.2 $mm^3$ voxel images revealed the best results. For insufficient lateral condensation, the best readings were found with periapical film followed by CCD and PSP. The assessment of teeth with root canals filled short of the apex showed the highest percentage of correct readings by CBCT and CCD. For the overfilled canal treatment group, PSP images and conventional periapical film radiographs had the best scores. Conclusion: CBCT was found to be successful in the assessment of teeth with ideal root canal treatment and teeth with canals filled short of the apex.

• 한국작물학회지
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• 제48권2호
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• pp.108-112
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• 2003

Foehn damage on rice plant is one of the important abiotic stresses in eastern costal area of Korea. To know the relationship between foehn impact and morphological traits of rice, wind tunnel method was used with 106 rice cultivars. Less influencing traits on foehn were short panicle, large panicle number per hill, thin panicle neck, and the flag leaf of narrow, short and thick. Leaf pubescence reduced the impact on foehn. 'Naepungbyeo' belong-ed to foehn tolerant varietal group, while 'Ansanbyeo' belonged to the opposite group. Three levels of root cutting treatment with two rice cultivars were conducted to evaluate the foehn impact using wind tunnel. The severity of wind damages was followed the sigmoidal curve duration of wind tunnel treatment were prolonged. Different responses of root cutting to wind tunnel treatment could be used to evaluate the severity of the foehn impact. 'Naepungbyeo' was one of the less implausible cultivars on foehn. 'Nae-pungbyeo' showed tolerant response to wind under 21% root removing treat-ment (20㎝ root cutting), however 'Ansanbyeo' was wilted under the same treatment. In case of 35 % root removing treatment(10㎝ root cutting), both rice cultivars failed to alive against foehn wind.

• 대한치과교정학회지
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• 제50권6호
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• pp.407-417
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• 2020

Objective: To investigate the dental phenotypes and treatment modalities (Tx-Mod) in Korean patients with Parry-Romberg syndrome (PRS) using longitudinal data. Methods: The samples consisted of 10 PRS patients, who were treated and/or followed-up at Seoul National University Dental Hospital between 1998 and 2019. Using a novel PRS severity index based on the numbers of the atrophy-involved area and asymmetry-involved item, we classified them into mild (n = 3), moderate (n = 2), and severe (n = 5). Dental phenotypes, including congenitally missing tooth (Con-Missing-Tooth), microdontia, tooth with short root (Short-Root), tooth with dilacerated root, and delayed eruption/impacted tooth, were investigated along with Tx-Mod. Results: The side of occurrence of all dental phenotypes showed 100% concordance with the side of PRS involvement. The most two common dental phenotypes were Con-Missing-Tooth and Short-Root (n = 29 and n = 17 in six patients). The sums of the average number of Con-Missing-Tooth and Short-Root increased from mild PRS to moderate PRS and severe PRS cases (1.0, 6.0, and 6.2). In terms of Tx-Mod, growth observation due to mild atrophy, fixed orthodontic treatment, and grafting were used for mild PRS cases. Tx-Mod for moderate PRS cases involved growth observation for surgery due to an early age at the initial visit. For severe PRS cases, diverse Tx-Mod combinations including unilateral functional appliance, fixed orthodontic treatment, growth observation, grafting, and orthognathic surgery were used. Conclusions: The novel PRS severity index may be useful to provide primary data for individualized diagnosis and treatment planning for PRS patients.

• 한국자원식물학회지
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• 제9권2호
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• pp.197-201
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• 1996

참당귀(當歸) 추대억제(抽臺抑制) 재배법(栽培法)을 개발하기 위하여 종자를 조기에 파종, 육묘하여 본포에 이식한 후 당년가을에 수확한 뿌리의 부위별(部位別) 주성분(主成分)을 관행재배한 당귀와 비교하므로서 1년생 당귀의 추대억제효과와 약재로서의 가치를 평가하고저 하였다. 1. 관행(慣行) 재배(栽培)한 2년생 당귀의 뿌리내 decursin 과 decursionol angelate의 함량을 합한 평균치는 6.47% 임에 비하여, 단기육묘(短期育苗)하여 수확한 1년생 뿌리 내에서의 함량은 4.82%로 낮은 경향이었다. 2. 약효성분(藥效成分)의 부위별(部位別) 함량은 세근(지근)과 피충부가 높은 반면 중심주에서는 낮은 경향이었다. 3. Decursin및 decursinol angelate의 구성비(構成比)는 1년생에서는 10 : 7.5, 2년생에서는 10 : 6의 비율로 2년생에서 는 decursinol angelate 함량이 감소하는 경향이었다. 또한 2년생에서는 부위에 관계없이 두성분의 구성비가 60% 정도로 안정적인데 반해, 1년생에서는 세근과 지근에서 decursional angelate 구성비가 높은 경향이었다. 4. 조기(早期) 육묘재배(育苗栽培)한 1년생 당귀의 생약적(生藥的) 가치(價値)는 일정 면적(面積)에서의 수량(收量)이나 또는 단순한 성분함(成分含) 양면(量面)에서 무리가 없을 것으로 사료되지만, 주성분인 decursin의 구조이성체인 decursinol angelate와의 구성비(構成比)에 따른 효능상의 문제는 추후 검토가 요망된다.