• Journal of the Korean GEO-environmental Society
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• v.17 no.3
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• pp.21-26
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• 2016

Soil particle shape analysis was conducted with sands from Jumujun, Korea and Ras Al Khair, Saudi Arabia. Two hundred times enlarged digital images of the particles of those two sands were obtained with an optical microscope. The resolution of the digital images was $640{\times}320$. By conducting digital image processing, the coordinates of the soil particle boundary were extracted. After mapping those coordinates to the complex space, Fourier transformation was performed and the coefficients of each trigonometry term were computed. The coefficients reflect the shape characteristics of the sand grains and are invariant to translation. To evaluate the shape itself excluding the size of the soil particle, the coefficient was normalized by the equivalent radius of soil particle; this is called Fourier descriptor. After analyzing the Fourier descriptors, it was found that the major characteristics of Jumunjin and Ras Al Khair sands were elongation and asymmetry. Furthermore, it was found that the particle shapes reflect the self-similar, fractal nature of the textural features. The effects of resolution on soil particle shape analysis was also studied. Regarding this, it was found that the significant Fourier descriptors were not significantly affected by the image resolution investigated in this study, but the descriptors associated with textural features were affected.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.3
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• pp.160-174
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• 2023

LiDAR plays a key role in autonomous vehicles, and to improve its visibility, it is necessary to improve its performance and the detection objects. Accordingly, this study proposes a shape for traffic safety signs that is advantageous for self-driving vehicles to recognize. Improvement plans are also proposed using a shape-recognition algorithm based on point cloud data collected through LiDAR sensors. For the experiment, a DBSCAN-based road-sign recognition and classification algorithm, which is commonly used in point cloud research, was developed, and a 32ch LiDAR was used in an actual road environment to conduct recognition performance tests for 5 types of road signs. As a result of the study, it was possible to detect a smaller number of point clouds with a regular triangle or rectangular shape that has vertical asymmetry than a square or circle. The results showed a high classification accuracy of 83% or more. In addition, when the size of the square mark was enlarged by 1.5 times, it was possible to classify it as a square despite an increase in the measurement distance. These results are expected to be used to improve dedicated roads and traffic safety facilities for sensors in the future autonomous driving era and to develop new facilities.

• Journal of the Korea Convergence Society
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• v.6 no.3
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• pp.59-64
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• 2015

A hinge is the most important part constituting door. Nowadays, the hinge is subdivided all the more under the category of the function, shape and material and is enlarged at the usage. Therefore, it is necessary to improve the manufacturing technique and more specialized design must be developed. As the structural analysis is carried on the hinge model mounted at door in this study, the deformation, stress distribution and fatigue life are analyzed when the door is applied with uniform force. The durabilities of hinge models due to each shape are anticipated through this study. It is thought to be contributed at developing and designing more improved hinge model with durability. And it is possible to be grafted onto the convergence technique at design and show the esthetic sense.

• The korean journal of orthodontics
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• v.43 no.4
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• pp.160-167
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• 2013

Objective: To evaluate the shapes and sizes of nasopharyngeal airways by using cone-beam computed tomography and to assess the relationship between nasopharyngeal airway shape and adenoid hypertrophy in children. Methods: Linear and cross-sectional measurements on frontal and sagittal cross-sections containing the most enlarged adenoids and nasopharyngeal airway volumes were obtained from cone-beam computed tomography scans of 64 healthy children ($11.0{\pm}1.8$ years), and the interrelationships of these measurements were evaluated. Results: On the basis of frontal section images, the subjects' nasopharyngeal airways were divided into the following 2 types: the broad and long type and the narrow and flat type. The nasopharyngeal airway sizes and volumes were smaller in subjects with narrow and flat airways than in those with broad and long airways (p < 0.01). Children who showed high adenoid-nasopharyngeal ratios on sagittal imaging, indicating moderate to severe adenoid hypertrophy, had the narrow and flat type nasopharyngeal airway (p < 0.01). Conclusions: Cone-beam computed tomography is a clinically simple, reliable, and noninvasive tool that can simultaneously visualize the entire structure and a cross section of the nasopharyngeal airway and help in measurement of adenoid size as well as airway volume in children with adenoid hypertrophy.

• Journal of Korean Neurosurgical Society
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• v.30 no.4
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• pp.437-442
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• 2001

Objective : The purpose of this study was to evaluate the risk factors of hematoma enlargement in patients with spontaneous intracerebral hemorrhage(ICH). Methods : A series of 214 ICH patients diagnosed by brain CT scan in our neurosurgery department from June 1995 to July 1998 were reviewed with clinical status, past medical histories, laboratory findings, CT findings and prognosis. Results : In 27 patients(12.6%), the second CT scan showed an enlarged hematoma. Age, sex, and site of hematoma were not related to hematoma enlargement. A long interval(>6 hours) between the onset and the 1st CT scan strongly reduced the incidence of hematoma enlargement. The incidence of hematoma enlargement significantly increased in patients with previous history of hypertension, cerebral infarction and ICH. This analysis also demonstrated the following independent factors predisposed to hematoma enlargement : initial high systolic blood pressure, high serum total protein, low serum albumin, low serum sodium, prolonged prothrombin time(>14 sec) and activated partial thromboplastin time(>29.5 sec), irregular hematoma shape, and combined intraventricular hemorrhage. Prognosis in the group of hematoma enlargement showed high mortality(48.1%) and poor outcome. Conclusion : Patients with previous history of hypertension, cerebral infarction and ICH, and with high systolic blood pressure, prolonged coagulation time, irregular hematoma shape and intraventricular hemorrhage in CT scan should be observed carefully. And, early surgical therapy of large hematoma and meticulous control of blood pressure may decrease the mortality and morbidity in patients with spontaneous ICH.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.1
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• pp.8-14
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• 1995

The behaviour of large school of sardine Sardinops melanosticta in and around the set-net were analyzed from sonar image recordings. The survey was conducted at Kishihata set-net in Japan from January 29th to February 22th 1992. The results obtained are summarized as follows ; 1. When large schools of sardine moved along the outside of the set-net. the shape of the school gradually changed, that was the front part extended forward in the direction of movement and the rear part concentrated in the same direction such that the school retained its original shape. 2. When large school of sardine entered the main-net of the set-net. the school was decentralized directly to the slope-net. to the central part. and to the opposite side, and then the fish school was concentrated as it moved directly to the slope-net. 3. When the size of the front part of the fish school enlarged. the maximum recorded moving speeds were 176cm/sec and 277cm/sec for schools inside and outside the set-net, respectively.

• Korean Journal of Veterinary Research
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• v.34 no.2
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• pp.219-227
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• 1994

The development of abomasum in fetuses between 60, 90, 120 days of gestation and neonates of Korean native goats was investigated by light, scanning and transmission electron microscopy. The results obtained were summarized as follows ; 1. The abomasum wall appeared to be differentiated into the epithelium, lamina propria, muscle layer, and serosa at 60 days of gestation. The epithelium was stratified columnar and these nuclei were located near the apical two thirds portion of the cell at 60 days of gestation, and then transformed into simple columnar epithelium with the flat basal nuclei. 2. The inner circular and outer longitudinal muscle layers were observed at 90 days of gestation and the blood vessels had become quite well developed as various arterioles, venules and capillaries of different size during this age. 3. Gastric pits were seen at 90 days of gestation and continued gradually to increase depth during gestation. 4. The mucous, parietal and chief cells appeared in epithelium at 90 days of gestation and continued gradually to increase in number during gestation. In 120 days fetuses and neonates, muscle layer had become very thickeness. 5. Scanning electron microscopically, the inner surface of the abomasum already consisted of wavy spiral folds which had many fine wrinkles at 60 days of gestation. In 90 day old fetuses, each spiral fold was enlarged and its surface was tended to be split into many straight longitudinal ridges and among these ridge were found shallow grooves, At 120 days, the subdivided swellings of ridges were progressively complicated in shape. In the neonates, the inner surface was flat and holed with many gastric pits. 6. Transmission electron microscopically, the epithelium was straified columnar and these nuclei were irregular shape at 60 days fetus. The parietal, chief and mucous cells were observed in 90 day old fetuses and continued gradually to increase in number during gestation. 7. The development of the abomasum was relatively slow at early stages, it was accelerated greatly in the last of gestation.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.3
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• pp.236-247
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• 2015

In this paper, the experimental equipments for ventilated supercavitation in cavitation tunnel is constructed and the basic data of ventilated supercavitation regard to the entrainment coefficient and Froude number is fulfilled. The experiments are conducted for the disk cavitator with injecting air and the pressure inside cavity and the shape of cavity are measured. As the entrainment coefficient increases while the Froude number is kept constant, the ventilated cavitation number decreases to a minimum value which decreases no more even with increasing the air entrainment. The minimum value of ventilated cavitation number, caused by the blockage effect, decreases according to increasing the diameter ratio of test section to cavitator. The cavity length is rapidly enlarged near the minimum cavitation number. In low Froude numbers, the cavity tail is floating up due to buoyancy and the air inside the cavity is evacuated from its rear end with twin-vortex hollow tubes. However, in high Froude numbers, the buoyancy effect is almost negligible and there is no more twin-vortex tubes so that the cavity shape becomes close to axisymmetric. In order to measure the cavity length and width, the two methods, which are to be based on the cavity shapes and the maximum width of cavity, are applied. As the entrainment coefficient increases after the ventilated cavitation number gets down to the minimum cavitation number, the cavity length still increases gradually. These phenomenon can be confirmed by the measurement using the method based on the cavity shapes. On the other hand, when the method based on the maximum width of cavity is used, the length and width of the cavity agree well with a semi-empirical formular of natural cavity. So the method based on the maximum width of cavity can be a valid method for cavitator design.

• Korean Journal of Human Ecology
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• v.3 no.1
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• pp.1-14
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• 2000

This paper is on the Kasaya that reveals conspicuously the religious meaning among the Korean Buddhist costumes. The Kasaya has the most special meaning among Korean costume culture. It has the most important historical value, for Buddhism is the oldest religion that begins at 4th century A.D.. It has the most unordinary shape that we could not find any other costume culture. It has very important meaning to study on the Kasaya in the religious and cultural history of Korean costume. We have to study Korean Kasaya from surveying Indian Buddhist Kasaya diachronicaly. Buddha establishes himself the rules of weaving, coloring and wearing Kasaya. Bunso costume(분소의)is the first shape of Kasaya that he has worn during his ascetic practice. Bunso costume was a kind of shari. It is made with diapers those clean ordure of baby It symbolizes the life of ascetic practice. However Buddha could not stick to it as the only costume of monks. From his age Buddhist devotees have thought Buddha and monks as sacred beings. So they eagerly want to Provide the sacred beings with foods. clothes and other things that samgha(승가) need to live and accomplish their duties. At that time there are many kings, aristocracies and rich merchants among the devotees. They often offered them the luxurious silk Kasaya. that the ascetic monks could not wear. to express their deep faith. So the rules of the samgha has been distorted. The samgha has enlarged day by day as a great huge religious association. There are many different shapes of Kasaya. The Buddhist samgha need to establish a minute and rigid rules of Kasaya to order living of monks and to teach the moral and educational life to ordinary people. That book of rule is Vinaya pitaka(율장) . There are many kinds of Vinaya pitaka. This paper surveys the rules of Kasaya from Southern Vinaya pitaka(남전율장). This study will be the basic ground to research the Korean Buddhist Kasaya.

• Structural Engineering and Mechanics
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• v.81 no.6
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• pp.691-703
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• 2022

To obtain the seismic response of lead-cored rubber, shape memory alloy (SMA)-rubber isolation Plate-shell Integrated Concrete Liquid-Storage Structure (PSICLSS), based on a PSICLSS in a water treatment plant, built a scale experimental model, and a shaking table test was conducted. Discussed the seismic responses of rubber isolation, SMA-rubber isolation PSICLSS. Combined with numerical model analysis, the vibration characteristics of rubber isolation PSICLSS are studied. The results showed that the acceleration, liquid sloshing height, hydrodynamic pressure of rubber and SMA-rubber isolation PSICLSS are amplified when the frequency of seismic excitation is close to the main frequency of the isolation PSICLSS. The earthquake causes a significant leakage of liquid, at the same time, the external liquid sloshing height is significantly higher than internal liquid sloshing height. Numerical analysis showed that the low-frequency acceleration excitation causes a more significant dynamic response of PSICLSS. The sinusoidal excitation with first-order sloshing frequency of internal liquid causes a more significant sloshing height of the internal liquid, but has little effect on the structural principal stresses. The sinusoidal excitation with first-order sloshing frequency of external liquid causes the most enormous structural principal stress, and a more significant external liquid sloshing height. In particular, the principal stress of PSICLSSS with long isolation period will be significantly enlarged. Therefore, the stiffness of the isolation layer should be properly adjusted in the design of rubber and SMA-rubber isolation PSICLSS.