• Korean Journal of Remote Sensing
• /
• v.36 no.6_1
• /
• pp.1291-1302
• /
• 2020

To verify the field-effectiveness of Terrestrial Laser Scanner (TLS), a terrestrial LiDAR was deployed to examine the damage properties of woods in forest fire area, then the data was compared with the results surveyed by a forestry expert. Four sample plots (30 m × 50 m, 0.15 ha) were set from the foot to the top of the mountain, and DBH, height, clear length, burned height, and crown length were investigated. Next, TLS collected information on damage characteristics found in the sample plots. This information was then compared with that amassed by the expert. The expert and the TLS survey results showed 30.8 cm and 29.9 cm for DBH, 15.8 m and 17.5 m for tree height, 8.4 m and 8.4 m for clear length, 4.0 m, 3.5 m for burned height, and 7.4 cm and 9.1 cm for crown length. With the exceptions of height and clear length, no notable discrepancy was observed between two methods. H/D ratio, CL/H ratio, and BH/CL ratio, all of which contribute to stability and decay rate of the stand, from the two methods were also compared. The human survey rated each ratio (H/D, CL/H, BH/CL in order) 51.3%, 47.1%, and 53.6%, while the TLS presented the results of 58.8%, 52.0%, and 38.7%.

• Proceedings of the KIPE Conference
• /
• 2003.07b
• /
• pp.824-827
• /
• 2003

Recently, Development of Rare Earth Permanent magnet with the high remanence, high coercivity allow the design of brushless motors with very high efficiency over a wide speed range. Cogging torque is produced in a permanent magnet by magnetic attraction between the rotor mounted permanent magnet and the stator teeth. It is an undesired effect that contributes to the machines output ripple, vibration, and noise. This cogging torque can be reduced by variation of magnet arc length, airgap length, magnet thickness, shifting the magnetic pole and varying the radial shoe depth and etc. In this paper, Some airgap length and magnet arc that reduce cogging torque are found by FEM(Finite element method). The SPM type of high-capacity BLDC motor is optimized as a sample model.

• Journal of architectural history
• /
• v.9 no.2 s.23
• /
• pp.7-17
• /
• 2000

The purpose of this study is the analysis of 'perpendicular crossing Dori' with a structural character of Ddeulzip in Andong cultural area. There are many structural methods to solve the problems of Ddeuljip which is connected space in the rectangular type. There are 'Slope Base', 'Woosangak' roof, 'Seosangak' roof, and '4 beam roof framing' Moreover, they have been used 'perpendicular crossing Dori'. Its characters are as follows ; 1. The 'perpendicular crossing Dori' structure is occurred in different depth of width and length space of 'ㄱ' typed plan. At that time the beam of width is crossed in the middle of the beam of length without the order under them. 2. The 'perpendicular crossing Dori' structure is the method of free depth of width in regular distance of column which is different from general usage of balcony order. 3. The 'perpendicular crossing Dori' structure is founded north-western area of Andong Cultural Area(Bonghwa, Andong, Youngju, and Yeacheun). The best old sample was in Andong(16C) and the next is Yeacheun(17C) and the last is Bonghwa(18C). 4. The frequency in use of roof type of 'perpendicular crossing Dori' structure is 64% of 'Seosangak' and 36% of 'Woosangak'. The sample of 'Woosangak' house of 'perpendicular crossing Dori' structure is concentrated in Bonghwa. 5. The best merit of the 'perpendicular crossing Dori' structure is usage of double swing window in front of Anbang, It is the spacial success which overcomes the structural limits. And it is the structural rationality.

• The korean journal of orthodontics
• /
• v.19 no.1 s.27
• /
• pp.219-243
• /
• 1989

The purpose of this study was to evaluate the effects of the chincap therapy on the craniofacial structure in persons with skeletal Class III malocclusion. The patients selected for this study were treated with extra-oral chincap therapy only. Both control and treatment samples were obtained from Seoul National University Hospital where these longitudinal data were gathered. 55 treated patients and 14 control patients were studied. The mean ages at the 1st evaluation was 8 years 3 months in the treatment sample and 9 years 4 months in the control sample. The duration of chincap therapy was variable but averaged 2 years of treatment. Post-treatment observation procedeeded for 1 year 2 months. Active treatment and post treatment effects were evaluated. The results were as follows: 1. Neither significant restraint nor acceleration of growth was found in the cranial base and maxilla during treatment. 2. A distal rotation of the mandibular complex was seen. 3. Some amount of restraint of growth was found in mandibular body length, ramus height, mandibular length during treatment. 4. The genial angle was reduced. 5. After removal of the chin-cap, forward displacement of the mandible took place.

• The Journal of Korean Medicine
• /
• v.28 no.3 s.71
• /
• pp.45-56
• /
• 2007

Objectives : We investigated the possibility of cervical spine misalignment caused by scalenus anticus syndrome to find out how it affects cervical spine misalignments. Methods : 28 patients with scalenus anticus syndrome (sample group), along with 21 participants without neck pain (control group), who attended the Dept. of Oriental Rehabilitation Medicine, College of Oriental Medicine, Dong-guk University from the 20th of June to the 30th of November, 2006 were investigated. After researching misalignments through neutrality, flexion and extension lateral x-ray examination views, we measured the difference of each length of cervical spine misalignment. We analyzed the relationships among the neutrality lateral, flexion lateral and extension lateral positions. Results : We found with statistical significance that there were differences in length of cervical spine misalignments between the sample and control groups. Furthermore, we found that C3 and C4 vertebra bodies were shown in lateral neutrality position, only C3 vertebra body in flexion lateral position, and C2, C3, and C4 vertebra bodies in extension lateral position. Conclusions : It is considered that scalenus anticus syndrome could increase cervical spine misalignment which could be a factor in causing cervical spine disease.

• The Korean Journal of Ceramics
• /
• v.5 no.2
• /
• pp.119-124
• /
• 1999

Silicon nitride ceramics with highly oriented microstructure were prepared by tape casting a slurry containing 5 wt% of the silicon nitride whiskers. The whiskers were aligned in the casting direction and worked as seeds for the grain growth. The anisotropy was observed from the sintering shrinkage, Vickers indentation crack lengths, and XRD patterns. The cracks were much longer on the surface normal to the aligned grains than on the tape casting surface where the lateral cracks were also observed. The effect of sintering additives and the annealing treatment on the indentation crack length was examined. The sample with higher silica content had longer cracks than the one with lower silica content. The crack length anisotropy increased after annealing at 2123K.

• The korean journal of orthodontics
• /
• v.10 no.1
• /
• pp.81-93
• /
• 1980

The interrelationships between growth rates (and size) of the selected cranifacial dimensions and body dimensions (height and weight) were investigated in the longitudinal data of primary school children from 6 to 11 years of age. The data were obtained from serial cephalometric radiographs and health record which were taken at one year interval. Regression analyses were used to analyze the data. The main concludions might be summarized as follows; 1. Size relationships between body height (and weigh) and S-Gn, posterior facial height (s-Go), total mandibular length (Ar-Gn) showed high significant correlation, but no association between body height, weight and anterior cranial base length (S-N). 2. Correlation coefficients between facial dimensions and body height (and weight) were getting lower with age increase. 3. At all age groups, significant prediction equation for some facial dimensions with body height and weight were obtained. 4. In this sample, the growth rates of facial dimensions and body height and weight showed almostly constant during this age period and the growth rate of body height and weight of girls was exceeded that of boys. 5. A relatively high degree of variation between individuals existed in the sample. 6. A positive correlation was found for the relationship between the growth rates of facial dimensions and those of body height (and weight) in boys and girls, but was not found in total samples.

• The Korean Journal of Applied Statistics
• /
• v.19 no.3
• /
• pp.461-479
• /
• 2006

This paper derives joint and conditional Lagrange multiplier tests based on Double-Length Artificial Regression(DLR) for testing functional form and/or the presence of individual(time) effect in a panel regression model. Small sample properties of these tests are assessed by Monte Carlo study, and comparisons are made with LM tests based on Outer Product Gradient(OPG). The results show that the proposed DLR based LM tests have the most appropriate finite sample performance.

• Journal of the Korean Society of Radiology
• /
• v.17 no.1
• /
• pp.167-173
• /
• 2023

X-ray general radiography is the simplest and most important one to get a lot of information. Nevertheless, current x-ray general radiography does not observation in-depth observation. Information about the anatomy of the human body and changes in disease in x-ray general radiography can be obtained but it is difficult to determine the size and shape of the actual lesion due to the disadvantage of expanding the image. In this study, PA and LAT images were acquired and cancer magnification was calculated in the images by measuring the distance of cancer samples. By adjusting the magnification the actual cancer length and thickness were measured and compared with the CT image and the actual cancer sample size. After the PA and LAT images of the inserted 6.0 mm cancer sample were obtained and the magnification was corrected, the length was 5.9 mm and the thickness was 6.1 mm. This value was measured similarly to the actual. The problem of obtaining the magnification that needs to know the actual length from the detector to the cancer sample was secured by obtaining the magnification through PA and LAT images and it is possible to accurately measure the cancer sample size. X-ray general radiography may provide useful information in situations where CT imaging is difficult.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.18 no.4
• /
• pp.34-40
• /
• 2004

In this paper, we have studied the OCT(Optical Coherence Tomography) system which has been advantages of high resolution, 2-D cross-sectional images, low cost and small size configuration. The characteristics of light source determine the resolution and coherence length. The light source has a commercial SLD with a central wavelength of 1,285 ill11, 35.3 nm(FWHM). The optical delay line is necessary to make equal with the optical path length to scattered light or reflected light from a sample. In order to make equal the optical path length, the stage that is attached to a reference mirror is controled by a step motor. And the interferometer is configured with the Michelson interferometer by using a single mode fiber, and the scanner can be focused on the sample by using a reference ann Also, the 2-dimension cross-sectional images were measured with scanning the transverse direction of the sample by using a step motor. After detecting the internal signal of lateral direction, a scanner is moved to obtain the cross-sectional image of 2-dimension by using step motor. A photodiode, which has high detection sensitivity and excellent noise characteristics has been used. The detected small signal has a noise and interference. After filtering and amplifying the signal, the output signal is demodulated the waveform And then, a cross-sectional image is seen through converting this signal into a digitalized signal by using an AID converter. The resolution of the sample is about 30${\mu}{\textrm}{m}$, which corresponds to the theoretical resolution. Also, the cross-sectional images of onion cells were measured in real time scheme.