• Journal of Korean Dental Science
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• 제4권1호
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• pp.1-5
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• 2011

Purpose: Exact knowledge of the location and dimension of the pulp chamber help to maintain the pulp healthy during operative procedure and also reduces the risk of perforation of pulp chamber during root canal treatment. This in-vivo study was carried out to measure critical morphology of pulp chamber of mandibular molar using intra-oral periapical radiograph. Materials and Methods: Mandibular molar teeth of 56 patients were evaluated. The mandibular molar teeth whose pulp chamber was not violated by caries, restoration, fracture crown and those having closed apex were included in the study. The intraoral periapical radiographs were taken with paralleling angle technique using radio-opaque grid with 1 mm space. This grid was placed directly on the film. Results: In 94% of the mandibular first molars specimens the pulp chamber ceiling was at the level of the cemento-enamel junction. The measurements showing the lowest percentage variance were buccal cusp to furcation (approximately 11%) and buccal cusp to pulp chamber ceiling (approximately 15%). The distance from the cusp tip to pulp chamber ceiling height was approximately 6.0 mm, the distance from the pulpal floor to the furcation was approximately 3.0 mm, and the average height of a pulp chamber was 1.5 to 2.0 mm. Conclusion: The exact knowledge of distances of pulp chamber from various anatomical landmarks helps in proper assessment of root canals and ultimately avoids the failure of root canal treatment.

• 한국작물학회지
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• 제45권3호
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• pp.171-175
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• 2000

황기의 개화, 결실 및 수분양식을 구명하여 품종육성의 기초자료를 얻고자 시기별 개화.결실 특성 및 수분방법별 결실율에 대한 시험을 수행하였던 바 다음과 같은 결과를 얻었다. 1. 황기의 개화는 원줄기의 20-22절위에서 첫 꽃이 피기 시작하여 분지 발생순으로 개화되며 7월 중.하순경에 개화하기 시작하적 10월 중.하순까지 계속 관화되는 무한화서이다. 2. 개화시기별로는 9월 상순에 개화한 화경수가 가장 많아 꼬투리 및 종실 수도 9월 상순에 개화한 화경에서 가장 많은 경향이었다. 3. 소화가 착생되는 부위의 길이는 6.6-7.3cm, 소화수는 화경당 13-17화, 착협률은 30-45%, 협당 종실수는 4.8-5.3위 정도였다. 4. 꼬투리는 수분 후 30일 경에 길이가 3.8cm로 최대에 달하며, 폭은 8mm정도이고 종실수는 7.3개정도 형성되었다. 5. 황기 꽃의 수분양식은 봉지 씌우기로 자가 수정시키는 경우 거의 결실되지 않았고, 인공수분에 의한 결실율은 7월 하순부터 8월 하순까지는 5%이하였으나 9월 상순 이후부터는 13%이상으로 높아지는 경향이며 타가수분을 하는 것으로 나타났다.

• 한국한의학연구원논문집
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• 제16권3호
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• pp.123-126
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• 2010

Objective : There are controversial opinions on the location of PC8 (Nogung). The one is to localize the point between the 2nd and 3rd metacarpal bone, the other is to localize the point between the 3rd and 4th metacarpal bone. The study was performed to provide an experimental evidence to standardize the location of PC8 point. Methods : We employed 30 healthy adults evenly in sex. To identify the location of PC8 in the hand, we took X-ray photograph in both hands of participants. Thin layer of leads were pasted on to PC7 and tip of middle finger prior to take X-ray photograph. The line connecting two points corresponding to the leads in X-ray film was read by a radiologist to decide that the line passes which side between the 2nd metacarpal space and the 3rd one. Results and Conclusions: The line passed the 3rd metacarpal space in 49 cases out of 60 hands (82 %). Data suggest that PC8 could be localized at the point between the 3rd and 4th metacarpal bone.

• 한국해양공학회지
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• 제21권3호
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• pp.71-76
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• 2007

Recently, many industries have been employing the application of laser beam welding, due to the resulting high welding quality, such as smaller width of melting and heat affective zone, smaller welding deformation, and fine grains of weldment, compared to arc welding. However, in order to appropriately utilize this welding process with steel structure, the characteristics of welding residual stresses and fracture toughness in welded joints are to be investigated for reliability. Therefore, in this study, the mechanical properties of weldments by arc and laser welding are investigated using FEM to confirm the weldability of laser welding to the general structural steel (HT50). The Charpy impact test and 3-points bending CTOD test are carried out in the range of temperatures between $-60^{\circ}C\;and\;20^{\circ}C$, in order to understand the effect on the fracture toughness of weldments. From the research results, it has been found that the maximum residual stress appears at the center of plate thickness, and that the fracture toughness is influenced by strength mis-match.

• The Korean Journal of Pain
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• 제9권2호
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• pp.407-411
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• 1996

Stereotactic radiofrequency dorsal root ganglionotomy can be very useful procedures for the treatment of pain emanating from the lumbar segmental nerves. This procedure is reserved for patients who have failed conservative interventional treatments and in whom open surgical intervention is not an option. The advantages of the radiofrequency lesion method are presented, excellent control of the lesion process using temperature monitoring to quantify the lesion size, prevent boiling, and to produce differential destruction of neural tissue. The afferent fibers in the ventral root which are spared by dorsal rhizotomy but nerve fibers with their cells in the ganglion from either dorsal or ventral root can be destructed with stereotactic radiofrequency ganglionotomy. This technique is performed using a 100 mm cannula with a 5 mm active tip. Repeated lateral fluoroscopic view should be taken to make sure that cannlua still resides within the superior, dorsal quadrant or the foramen. With the cannula in this position, electrostimulation is performed and good paresthesia on the leg should be noted with 0.3 and 0.5 volt at 50 Hz stimulation. At 2Hz stimulation distinct dissociation between motor and sensory should be shown. Percutaneous lumbar ganglionotomy have carried out under local anesthesia on inpatient basis in 6 patients. A series of 5 patients with metastatic cancer pain and a patient with compression fracture have been relieved of pain without serious complications.

• 전기학회논문지
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• 제64권6호
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• pp.900-911
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• 2015

In this paper, 3D face recognition model is designed by using Polynomial based RBFNN(Radial Basis Function Neural Network) and PNN(Polynomial Neural Network). Also recognition rate is performed by this model. In existing 2D face recognition model, the degradation of recognition rate may occur in external environments such as face features using a brightness of the video. So 3D face recognition is performed by using 3D scanner for improving disadvantage of 2D face recognition. In the preprocessing part, obtained 3D face images for the variation of each pose are changed as front image by using pose compensation. The depth data of face image shape is extracted by using Multiple point signature. And whole area of face depth information is obtained by using the tip of a nose as a reference point. Parameter optimization is carried out with the aid of both ABC(Artificial Bee Colony) and PSO(Particle Swarm Optimization) for effective training and recognition. Experimental data for face recognition is built up by the face images of students and researchers in IC&CI Lab of Suwon University. By using the images of 3D face extracted in IC&CI Lab. the performance of 3D face recognition is evaluated and compared according to two types of models as well as point signature method based on two kinds of depth data information.

• 대한조선학회논문집
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• 제50권6호
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• pp.421-428
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• 2013

This study aims at numerically investigating the angle of attack characteristics of the rudder behind a rotating propeller. The rotating propeller of 5 blades and the full spade rudder are placed in the numerical water tunnel with a uniform flow condition to consider propeller-rudder interaction. The turbulence closure model is employed to simulate the three-dimensional unsteady incompressible viscous turbulent flow around the propeller and the rudder. The present numerical method are well verified by comparing with the experimental results. In order to identify the dependence of the angle of attack of the rudder on the rudder angle, a wide range of rudder angles is considered. The present study carried out the quantitative and qualitative analysis of the angle of attack in terms of the pressure distribution, streamlines and the evaluation of the flow incidence, resulting in that the angle of attack increases as we move from the root and the tip to the center of the rudder, regardless of the rudder angle. The distribution of the angle-of-attack along the span is strongly affected by rotating propeller flow and rudder angle. Consequently, the distribution of the angle-of-attack of the oncoming flow against the rudder leading edge plays a role in determination of rudder performance.

• Corrosion Science and Technology
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• 제6권3호
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• pp.103-111
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• 2007

The effect of stress factors on the growing process of stress corrosion cracking (SCC) of the sensitized 18-8 stainless steel in high temperature water was investigated using equations of crack growth rate derived from applying electric circuits to SCC corrosion paths. Three kinds of cross sections have to be considered when electric circuit is constructed using total current. The first is ion flow passage area, $S_{sol}$, of solution in crack, the second is total dissolving surface area, $S_{dis}$, of metal on electrode of crack tip and the third is dissolving cross section, $S_{met}$, of metal on grain boundary or in base metal or in welding metal. Stress may affect each area. $S_{sol}$ may depend on applied stress, $\sigma_{\infty}$, related with crack depth. $S_{dis}$ is expressed using a factor of $\varepsilon(K)$ and may depend on stress intensity factor, K only. SCC crack growth rate is ordinarily estimated using a variable of K only as stress factor. However it may be expected that SCC crack growth rate depends on both applied stress $\sigma_{\infty}$ and K or both crack depth and K from this consideration.$\varepsilon(K)$ is expressed as ${\varepsilon}(K)=h_2{\cdot}K^2+h_3{\cdot}K^3$ when $h_{2}$ and $h_{3}$ are coefficients. Also, relationships between SCC crack growth rate, da/dt and K were simulated and compared with the literature data of JBWR-VIP-04, NRC NUREG-0313 Rev.2 and SKIFS Draft. It was pointed out in CT test that the difference of distance between a point of application of force and the end of starter notch (starting point of fatigue crack) may be important to estimate SCC crack growth rate. An anode dissolution current density was quantitatively evaluated using a derived equation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권10호
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• pp.4903-4929
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• 2018

In this study, a fully automatic pose and expression invariant 3D face alignment algorithm is proposed to handle frontal and profile face images which is based on a two pass course to fine alignment strategy. The first pass of the algorithm coarsely aligns the face images to an intrinsic coordinate system (ICS) through a single 3D rotation and the second pass aligns them at fine level using a minimum nose tip-scanner distance (MNSD) approach. For facial recognition, multi-view faces are synthesized to exploit real 3D information and test the efficacy of the proposed system. Due to optimal separating hyper plane (OSH), Support Vector Machine (SVM) is employed in multi-view face verification (FV) task. In addition, a multi stage unified classifier based face identification (FI) algorithm is employed which combines results from seven base classifiers, two parallel face recognition algorithms and an exponential rank combiner, all in a hierarchical manner. The performance figures of the proposed methodology are corroborated by extensive experiments performed on four benchmark datasets: GavabDB, Bosphorus, UMB-DB and FRGC v2.0. Results show mark improvement in alignment accuracy and recognition rates. Moreover, a computational complexity analysis has been carried out for the proposed algorithm which reveals its superiority in terms of computational efficiency as well.

• 원예과학기술지
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• 제17권6호
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• pp.768-769
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• 1999

숙근 안개초의 정단부를 이용한 기내증식은 'Bristol Fairy'에서 BA $0.2mg{\cdot} L^{-1}$, NAA $0.2mg{\cdot}L^{-1}$혼합처리로 생체중, 신초수를 증가시켰고, 'Red Sea'에서는 BA $0.2mg{\cdot}L^{-1}$, NAA $0.1mg{\cdot}L^{-1}$ 혼합처리시 부정아의 수와 길이가 증가되었다. 'Bristol Fairy'에서 투명화 발생은 $7cm{\times}13cm$(지름${\times}$높이)의 배양용기 사용으로 억제되었다. 마개의 aeration처리와 agar의 농도는 투명묘 발생에 영향을 미치지 못하였으나 신초의 신장을 촉진하였다. 한편 한천의 농도가 높아질수록 부정아의 형성이 억제되었다.