• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.3
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• pp.103-115
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• 2003

This study examines groundwater movement system analysis and movement forecast algorithm using finite element method. The target is Cheongha-myeon area, Bukgu, Pohang-city which has many difficulties in water supply during drought period. From the comparison of the differences between obtained values by WINFlOW model and observed values, it is thought that groundwater head distribution under steady flow is reflected well at the level of reliability Groundwater movement of study area shows stable pattern from western watershed to eastern coastal area while flow path is dense and steep in the center of the coastal area. The results of particle tracing for each well show a comparatively straight line from the western boundary side to the observation position at the upper area of the well, and are analyzed as it diffuses according to getting closer to the coast at the lower area of the well. The result of effect circle examination attendant on pumping amount in study area shows variation tendency that groundwater head decreases at the side and the lower area more than at the upper area of the well when groundwater flows from west to east(coast). As mentioned above, satisfactory results of groundwater movement analysis using WINFlOW model, two dimensional groundwater movement analysis model, are obtained through the great decrease of physical uncertainty of groundwater movement system.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.2
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• pp.89-95
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• 2010

This is the third series of article on dental occlusion and relationship to TMD and systemic symptoms. In this part of the series, it will overview the theory, treatment methods, criteria, their limitation of Chirodontics, Dental Distress Syndrome (DDS) and quadrant theorem(QT). Chirodontics has its root on Chiropractic and to maintain the 'healthy status' of TMJ with stable occlusion via dental treatment. Dental distress syndrome on the other hand believes that all the TMD has originated from reduced or collapse of posterior support and incorrect posterior vertical support had caused imbalance of the head and neck structure which eventually affect the whole body symptoms. The analysis and treatment is planned using quadrant theorem where the position of head, rotatory pivot point and occlusal plane is analyzed.

• Korean Journal of Applied Biomechanics
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• v.17 no.1
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• pp.41-52
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• 2007

The present study analyzed the two hand backhand stroke motion of six female high school tennis players who won the championship at the National Athletic Meeting in 2006, and drew conclusions as follows. The open angle of the racket at the moment of impact was 90 degree without significant difference among the players, making a wide contact between the ball and the racket. The racket angle was 43 degree at take back and 91 at impact, showing a style of holding the racket rather upright in general. In back swing from the top to the impact, the shoulders and the hips turned by 97 degree and 40 degree, respectively. At the moment of impact, the height of the impact was 54%H, and the position of the impact was 10%H ahead of and 37%H left from the central axis of the body. The right hand made a continental grip and the left hand made a Western or semi Western grip. Through the entire swing motion, the grip angle of the left hand was smaller than that of the right hand, and those who maintained a large grip angle of the right hand at the moment of take back put the racket head slightly farther from the body. In the swing of the racket head from the lowest point to the impact, the vertical length of movement was 11%H and the horizontal length of movement was 60%H, quite long.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.4
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• pp.418-423
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• 2014

Small hydropower has been considered as a solution to resolve the problem of exhaustion of fossil fuel and industrial pollution. In this study, we developed and tested a Cross-Flow Turbine with two guide vanes to optimize the small hydropower for the site condition with large fluctuation of head and flow rate. Furthermore, in the condition of constant inlet head, CFD analysis was carried out to analyze the effect of air suction and valve position on the performance characteristics. The results showed that the air suction can minimize the hydraulic loss caused by the Recirculation flow in the runner passage and flow impact on main shaft so that it can increase the turbine efficiency and output power.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.391-394
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• 1998

The man-machine interface Is an important factor in the computer system, and it is thought that line-of-sight (LOS) detection technology will allow significant advances in this field. Techniques for detecting LOS for use in human interfaces have been studied［1]［2］. In earlier studies, however, LOS was detected with a head piece, goggles, or through fixing the position of the head. The limitations imposed by these fixed conditions render them unsuitable far use in interfaces, as they have adverse mental or physical effects on humans. Therefore. they have not been sufficiently developed for practical application. Research on non-contact LOS detection is expected to result in a usable LOS man-machine interface［3］［4］, and the current study is intended to be a step in that direction. The authors used color contact lenses for LOS detection, and applied this new method to a computer interface. The use of color contact lenses simplifies image processing. The algorithm used in this study is sufficiently accurate for practical applications. This technique can be used in input devices, in virtual reality applications, and in human engineering research.

• Korean Journal of Bronchoesophagology
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• v.16 no.2
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• pp.138-144
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• 2010

Background: Tracheal deviations are encountered frequently in head and neck tumors especially in thyroid cancer. Dyspnea and stridor are symptom calling for surgery. The method of evaluation in tracheal deviation is not well established yet. This paper is aimed to suggest objective tools to evaluate tracheal deviation in relation to cervical vertebra. Material and Method: Ten cases of thyroid cancers were recruited retrospectively. Tracheal inner shadow and shape of cervical vertebra were reconstructed three dimensionally using 3D-doctor to compare position of trachea in relation to vertebral body. Extent of deviation was scored in relation to both lateral borders of vertebral body. Angles between trachea and spinous process were measured in axial CT and compared between study group and control group. Results: Deviation scores were statistically significant between study group (mean=1.1) and control group (mean=0) (p=0.0008). Deviation angles at maximal tumor size in study group (mean=160.3 Degrees) and deviation angles of control group (mean=177.1 Degrees) were statistically significant (p=0.0007). Angles at maximal deviation of three dimensional images ages in study group (mean=162.6 Degrees) and deviation angles of control group (mean=177.1 Degrees) were statistically significant (p=0.0089). Conclusion: Tracheal deviation can be evaluated using scoring of three dimensional images and measuring angle between trachea and vertebral spine.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.12 s.255
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• pp.1611-1617
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• 2006

A compact and two-dimensional atomic force microscope (AFM) using an orthogonal sample scanner, a calibrated homodyne laser interferometer and a commercial AFM head was developed for use in the nano-metrology field. The x and y position of the sample with respect to the tip are acquired by using the laser interferometer in the open-loop state, when each z data point of the AFM head is taken. The sample scanner which has a motion amplifying mechanism was designed to move a sample up to $100{\times}100{\mu}m^2$ in orthogonal way, which means less crosstalk between axes. Moreover, the rotational errors between axes are measured to ensure the accuracy of the calibrated AFM within the full scanning range. The conventional homodyne laser interferometer was used to measure the x and y displacements of the sample and compensated via an X-ray interferometer to reduce the nonlinearity of the optical interferometer. The repeatability of the calibrated AFM was measured to sub-nm within a few hundred nm scanning range.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.1
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• pp.31-39
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• 2001

The purpose of this study is to reveal the factors leading to the problem of unilateral condylar fractures and suggest a treatment guideline of treatment for good prognosis in surgical treatment. The factors can be age, sex, fracture site, degree of displacement, posterior occlusion loss, post-operative alteration of condylar head position, post-operative condylar head resorption, and maxillomandibular fixation period. One hundred and eleven patients with unilateral condylar fractures, who were treated by surgical method from 1990 Feb. to 2000 Feb., were studied. Minimum follow-up period was 6 months. The results were as follows ; 1. In the age group of $41{\sim}60$, females had significantly higher complication rate than males, therefore we must be careful about treatment of female in this age group 2. In level I fractures of the mandibular condyle, because there were abundant complications when the patients were treated with fragment removal, conservative treatment is recommended over the surgical approach. 3. There were no differences in the complication rate, in the level II, III fractures. but were severe complications in the cases of patients treated by Dr.Nam's method or fragment removal. Therefore, open reduction and internal fixation is recommended over Dr.Nam's method or fragment removal. 4. In level IV fractures, open reduction and internal fixation is recommended 5. Although there was a higher complication rate depending on the degree of deviation, there was no correlation between the degree of deviation and development of complications in each level of fracture 6. Because the complication rate was higher in cases of condylar resorption, vertical dimension loss, and alteration of condylar head position, we must make an effort to prevent such complications during treatment

• MALSORI
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• no.19_20
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• pp.58-87
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• 1990

According to Government Phonology, at 1 phonological positions save the domain's head must be licensed in order to appear in the syllable structure. A non-nuclear head is licensed by the following nucleus, and the nuclei with phonetic content are licensed through government by the nuclear head of the domain at the level of the nuclear projection. Therefore, in the theory of Government Phonology it is claimed that words always end with a nucleus. With regard to the licensing of empty nuclei, Kaye(1990a) proposes the 'Empty Category Principle' and its sub-theory of 'Projection Government'. Government Phonology claims that a nucleus which dominates a vowel that regularly undergoes elision in certain contexts is underlyingly empty. This underlying empty nucleus is not manifested phonetically when it is properly governed by an unlicensed(i, e, a nucleus filled with a full vowel). It is when proper government fails to apply, that the empty nucleus is phonetically Interpreted. The purpose of this paper is to present a principled account of the process of $[i]{\Leftrightarrow}{\emptyset}$ alternation in Korean. Following Kaye's proposal, we assume that [i] of Korean is underlyingly empty. This position is pronounced as [i] if it is unlicensed, and is not phonetically realized if is licensed. Empty nuclei ape devided into two categories: domain-internal and domain-final. Firstly, we consider the question why Korean has little word ending with [i]. As for this, ECP states that domain-final empty nuclei are not pronounced if the language licenses domain-final empty nuclei. Whether a final empty nucleus may occur in the structure is parametric variation. This property is seen from the fact that words may appear to end in consonants in this language. Since Korean abounds with words ending in a consonant, it licenses domain-final empty nuclei. Therefore, it is quite natural that Korean has little word ending with [i]. Secondly, word-internal empty nuclei of Korean respect proper government and inter-onset government. That is, an empty nucleus in word-internal position will be pronounced with the vowel [i] if either proper government or inter-onset government fail to apply. Inter-onset government refers to the government established between two onsets across an empty nucleus. Thirdly, we consider words ending with [i], which seems to be exceptional to the final licensing. Host of them are. either mono-syllabic verbs(for instance, [s'i-] 'to write') or derived adjectives ending with [p'i] (for instance, [kip'i-] 'be happy'). As for the former, the 'inaccessibility for proper government' is applied because the empty nucleus appears in the first syllable. In latter case, domain-final empty nuclei are pronounced as [i] because of government-licensing. That is, final empty nucleus is pronounced to license the preceding onset dominating negatively charmed segments which empty nucleus of Korean cannot license.

• Journal of Veterinary Clinics
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• v.11 no.2
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• pp.529-537
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• 1994

Sector scanner which has a conical end is used to image through the intercostal space because heart is protected by the ribs. Cardiac data published all around the world were also obtained by sector scanner. Although scanners being used in every small animal practice and animal hospital at college in Korea include convex ape and linear type, linear type is not appropriate f3r cardiac scan because of a wide contact surface. The purpose of this study is to establish ultrasonographic images of normal cardiac structures by measuring shape, size of reflectable cardiac structure according to restraint position in scanning normal heart of the puppies with 6.5 MHz convex scanner(SonoAce 4500, Medison, Korea) used in our veterinary teaching hospital, Seoul national university. Seventeen male and female puppies considered having healthy hear by X-ray and clinical examination are used feom April to July 1994. Scanning point selection of probe head and the distinction of imaged cardiac structures were accomplished by necropsy and cardiac scanning performed through thoracotomy under general anesthesia. At 10 o'clock position of transducer(at an angle of 30$^{\circ}$ between imaginary line from elbow joint to 3rd sternum and probe head, 60$^{\circ}$ from body surface, 4th intercostal space of right thorax) with the marker of scanner toward the head of dogs right atrium, left atrium and left ventricle were observed in 2, 3, 4, 5 intercostal space(2cm from the sternum) of experimental dog positioned ventrodorsally under general anesthesia. Under these conditions, the numerical values of imaged diastolic hear are as follows : the distance from skin to apex(mean$\pm$S.D) 47.53$\pm$6.94mm, thickness of left ventricular wall 6.00$\pm$1.60mm, length of left ventricle 16.27$\pm$5.31mm, width of left ventricle 15,33$\pm$4.25mm, length of left atrium 12.33$\pm$3.82mm, width of left atrium 11. 33$\pm$3.94mm, length of right atrium 1.00$\pm$2.41mm, width of right atrium 11.21$\pm$2.76mm and the area of left ventricle 270.92$\pm$109.81mm$^2$, area of left atrium 98.00$\pm$41.08mm$^2$, area of right atrium 62.75$\pm$21.04mm$^2$.