• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.25 no.2
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• pp.319-330
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• 1995

This study was designed to evaluate the interrelationship between the condylar head position in transcranial view and the articular disc position in the arthrography. The condylar positions were assessed by subjective method and linear measurement method on the transcranial view. The subjects for this study consisted of 24 symptomatic joints with normal disc position, 37 joints with anterior disc displacement with reduction and 44 joints with anterior disc displacement without reduction that were classified by arthrotomography under the fluoroscopic guidance. The interrelationship between the condylar head position in transcranial view and the articular disc position in the arthrography was evaluated by Chi square test. The obtained results were as follows : 1. There was no significant interrelationship between the position of condylar head in closed mouth state on transcraniaJ view and articular disc position in the arthrography (p>0.05). 2. There was no significant interrelationship between the changes of interarticular distance in 1 inch opening state and articular disc position in the arthrography (p>0.05). 3. There was no significant interrelationship between the position of condylar head related to the apex of articular eminence in 1 inch opening state and articular disc position in the arthrography(p>0.05). 4. There was significant interrelationship between the changes of interarticular distance that is assessed by linear measurement method in maximum opening state and articular disc position in the arthrography(p<0.05), but there was no significant interrelationship when the condylar head position was assessed by subjective method(p>0.05). 5. There was significant interrelationship between the degree of condylar translation in maximum opening state and articular disc position in the arthrography(p<0.05). 6. The correlation coefficient between two methods to assess the position of condylar head were 0.7989: the condylar head position in articular fossa in closed state, 0.6847: interarticular space in 1 inch opening state, 0.8965: the degree of condylar translation in 1 inch opening state, 0.5944: the changes of interarticular space in maximum opening state, 0.9215: the degree of condylar translation in maximum opening state.

• Korean Journal of Remote Sensing
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• v.24 no.4
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• pp.359-367
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• 2008

TRMM TMI data were used to investigate a relationship between physical parameters from microwave sensor and typhoon intensities from June to September, 2004. Several data such as 85GHz brightness temperature (TB), polarization corrected temperature (PCT), precipitable water, ice content, rain rate, and latent heat release retrieved from the TMI observation were correlated to the maximum wind speeds in the best-track database by RSMC-Tokyo. Correlation coefficient between TB and typhoon intensity was -0.2 - -0.4 with a maximum value in the 2.5 degree radius circle from the center of tropical cyclone. The value of correlation between in precipitable water, rain, latent heat, and typhoon intensity is in the range of 0.2-0.4. Correlation analysis with respect to storm intensity showed that maximum correlation is observed at 1.0-1.5 degree radius circle from the center of tropical cyclone in the initial stage of tropical cyclone, while maximum correlation is shown in 0.5 degree radius in typhoon stage. Correlation coefficient was used to produce regressed intensities and adopted for typhoon Rusa (2002) and Maemi (2003). Multiple regression with 85GHz TB and precipitable water was found to provide an improved typhoon intensity when taking into account the storm size. The results indicate that it may be possible to use TB and precipitable water from satellite observation as a predictor to estimate the intensity of a tropical cyclone.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.4
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• pp.342-351
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• 2010

UAV (Unmanned Aerial Vehicle) have an INS(Inertial Navigation System) equipment and also have an electro-optical Equipment for mission. This paper proposes the vision based attitude estimation algorithm using Kalman Filter and Optical flow for UAV. Optical flow is acquired from the movie of camera which is equipped on UAV and UAV's attitude is measured from optical flow. In this paper, Kalman Filter has been used for the settlement of the low reliability and estimation of UAV's attitude. Algorithm verification was performed through experiments. The experiment has been used rate table and real flight video. Then, this paper shows the verification result of UAV's attitude estimation algorithm. When the rate table was tested, the error was in 2 degree and the tendency was similar with AHRS measurement states. However, on the experiment of real flight movie, maximum yaw error was 21 degree and Maximum pitch error was 7.8 degree.

• Journal of Korean Academy of Nursing
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• v.27 no.2
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• pp.303-314
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• 1997

This is descripitive study conducted to identify educational needs of mothers of nephrotic syndrome patients and tie degree of nerses' educational performances perceived by mothers who look after mainly nephrotic syndrome patients. The study subjects were composed of 74 mothers of nephrotic syndrome patients whose children were hospitalized in 2 Pediatric wards of University Hospital in Seoul and 1 in Pen from June in 1996 to Januaryin 1997. A questionaire for this study was item Kikert type 5 point scale, developed on the basis of previous literature and researcher's clinical experience and the reliability of the used instruments was α=.97. The data analysis was done by SAS. t-test, and ANOVA were done to determine the effect of general characteristics of subjects on their educational needs. Pearson correlation was done to measure relations between general characterictics of subjects and their educational needs and Stepwise Multiple Regression was done to test a variable affecting educational needs. The results were as follows. 1. Mean score of educational needs of subjects was 137.06(Maximum 176). The score of the educational needs of home care was the highes, but the question numbers(of that category) are smaller than others. So, the educational need of the diagnosis art treatment was regarded as the highest in contents. 2. The mean score of nurses' educational performances was very low, 74.91(Maximum 176). Nurse's educational performances score in the diagnosis and treatment of the disease ranked as the highest Burt that score in the care during hoapitalization was the highest in contents as the educational needs was. 3. The number of children excepting the patient (r²=.215289. p=.006) and the age of patient(r²=.23770, p=.001) were emerged as important variables affecting the degree of mother's educational need.

• Journal of Forest and Environmental Science
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• v.13 no.1
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• pp.81-89
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• 1997

Urban river needs continuous observation for the river conservation because river surrounding environment sensitivly is changed by human activity. In order to grasp the effect of human activity against Taebaek river in Chunchon city, this research analysed the channel shape change, fluctuation volume and bias degree over five times, for June, 1993 to June, 1996. The results were as follows : 1. The change of channel shape on each surveying time mainly occurred in June, 1996 and maximum deposition. $1,247m^3$ occurred on 19~20 section, maximum scouring, $340m^3$ occurred on 6~7 section, 2. When comparing with June, 1993, increased deposition volume of channelbed was about $4,600m^3$ in June, 1996, 3. The bias degree of channel mainly occurred in June, 1996 of surveying times and at 6, 7, 15, 16, 17, 18, 19, 20 line of surveying lines.

• The korean journal of orthodontics
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• v.46 no.5
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• pp.310-322
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• 2016

Objective: The aim of this study was to determine the optimal loading conditions for pure intrusion of the six maxillary anterior teeth with miniscrews according to alveolar bone loss. Methods: A three-dimensional finite element model was created for a segment of the six anterior teeth, and the positions of the miniscrews and hooks were varied after setting the alveolar bone loss to 0, 2, or 4 mm. Under 100 g of intrusive force, initial displacement of the individual teeth in three directions and the degree of labial tilting were measured. Results: The degree of labial tilting increased with reduced alveolar bone height under the same load. When a miniscrew was inserted between the two central incisors, the amounts of medial-lateral and anterior-posterior displacement of the central incisor were significantly greater than in the other conditions. When the miniscrews were inserted distally to the canines and an intrusion force was applied distal to the lateral incisors, the degree of labial tilting and the amounts of displacement of the six anterior teeth were the lowest, and the maximum von Mises stress was distributed evenly across all the teeth, regardless of the bone loss. Conclusions: Initial tooth displacement similar to pure intrusion of the six maxillary anterior teeth was induced when miniscrews were inserted distal to the maxillary canines and an intrusion force was applied distal to the lateral incisors. In this condition, the maximum von Mises stresses were relatively evenly distributed across all the teeth, regardless of the bone loss.

• Journal of the Korean Solar Energy Society
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• v.23 no.3
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• pp.63-71
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• 2003

According to the recent report, the lighting energy consumption of commercial buildings reaches to $30%\sim40%$ of the total energy consumption. It is more than that of cooling & heating energy consumption and it is the major target of energy-saving policy. It is obvious that they are interested in natural lighting device such as Light-shelf for the purpose of raising the lighting energy-saving efficiency. In most of highly developed countries, a thorough study on Light-shelf makes it possible to propose a practical plan while at home there leaves much to be desired to study a guiding principle of optimum plan in spite of its efficiency based on experiments using scale4 model and analysis of simulation. Aiming at making an optimum plan of Light-shelf suitable for the domestic situation, this study is worked by experiments using light-shelf and analysis of variables using illumination program. The experiments is to analyse the efficiency of Light-shelf on condition of the sky and the analysis is to make the simulation using illumination program. This study is composed of 1) the analysis of light with some variables such as presence of light-shelf and degree of angle using 1/2 scaled model 2) making the simulation using Lightscape, illumination program, In brief, concerning presence of light-shelf, it causes little difference in its efficiency in the overcast sky, whereas it decreases an illuminance of window side and provides inner side with the light, which decreases the ratio of the maximum to the minimum inner illuminance and makes the inner of illuminance to range evenly in the clear sky. On degree of angle, as the daylight increases in proportion of degree of angle, the ratio of the maximum to the minimum inner illuminance decreases, which makes it possible to increase the proportion of inner daylight.

• Journal of the Korea Society of Computer and Information
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• v.20 no.2
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• pp.63-70
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• 2015

In the absence of a polynomial time algorithm capable of obtaining the exact solutions to it, the domatic number problem (DNP) of dominating set (DS) has been regarded as NP-complete. This paper suggests polynomial-time complexity algorithm about DNP. In this paper, I select a vertex $v_i$ of the maximum degree ${\Delta}(G)$ as an element of a dominating set $D_i,i=1,2,{\cdots},k$, compute $D_{i+1}$ from a simplified graph of $V_{i+1}=V_i{\backslash}D_i$, and verify that $D_i$ is indeed a dominating set through $V{\backslash}D_i=N_G(D_i)$. When applied to 15 various graphs, the proposed algorithm has succeeded in bringing about exact solutions with polynomial-time complexity O(kn). Therefore, the proposed domatic number algorithm shows that the domatic number problem is in fact a P-problem.

• Earthquakes and Structures
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• v.15 no.6
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• pp.687-699
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• 2018

This paper investigates the pseudo-static analysis of reinforced slopes with geosynthetics under the influence of the uniform surcharge to evaluate the maximum tensile force of reinforcements. The analytical approach has basically been used to develop the new practical procedure to estimate both tensile force and its distribution in the height of the slope. The base of developed relationships has been adapted from the conventional horizontal slice method. The limit equilibrium framework and the assumptions of log-spiral failure surface have directly been used for proposed analytical approach. A new analytical approach considering a single layer of non-cohesion soil and the influence of uniform surcharge has been extracted from the 5n equation and 5n unknown parameters. Results of the proposed method illustrated that the location of the surcharge, amount of internal friction and the seismic coefficient have the remarkable effect on the tensile force of reinforcement and might be 2 times increasing on it. Furthermore, outcomes show that the amount of tensile force has directly until 2 times related to the amount of slope angle and its height range. Likewise, it is observed that the highest value of the tensile force in case of slope degree more than 60-degree is observed on the lower layers. While in case of less degree the highest amount of tensile force has been reported on the middle layers and extremely depended to the seismic coefficient. Hence, it has been shown that the tensile force has increased more than 6 times compared with the static condition. The obtained results of the developed procedure were compared with the outcomes of the previous research. A good agreement has been illustrated between the amount results of developed relationships and outcomes of previous research. Maximum 20 and 25 percent difference have been reported in cases of static and seismic condition respectively.

• Geomechanics and Engineering
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• v.18 no.1
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• pp.11-20
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• 2019

The purpose of this study was to propose a new approach for quantifying in situ rock mass damage, which would include a degree-of-damage and the degraded strength of a rock mass, along with its prediction based on real-time Acoustic Emission (AE) observations. The basic approach for quantifying in-situ rock mass damage is to derive the normalized value of measured AE energy with the maximum AE energy, called the degree-of-damage in this study. With regard to estimation of the AE energy, an AE crack source location algorithm of the Wigner-Ville Distribution combined with Biot's wave dispersion model, was applied for more reliable AE crack source localization in a rock mass. In situ AE wave attenuation was also taken into account for AE energy correction in accordance with the propagation distance of an AE wave. To infer the maximum AE energy, fractal theory was used for scale-independent AE energy estimation. In addition, the Weibull model was also applied to determine statistically the AE crack size under a jointed rock mass. Subsequently, the proposed methodology was calibrated using an in situ test carried out in the Underground Research Tunnel at the Korea Atomic Energy Research Institute. This was done under a condition of controlled incremental cyclic loading, which had been performed as part of a preceding study. It was found that the inferred degree-of-damage agreed quite well with the results from the in situ test. The methodology proposed in this study can be regarded as a reasonable approach for quantifying rock mass damage.