• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.203-206
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• 2005

본 연구에서는 카오스 2중 Tent 사상에 의한 랜덤 주파수 캐리어 발생기를 제안하고 있다. 제안된 방법은 2중 텐트사상의 분기트리(Bifurcation Tree)에서 카오스 발생 영역인 $\lambda$=0.99을 이용하여 랜덤 수글 발생시키고 있다. 제안된 방법과 종전의 LCG(Linear Congruential Generator)에 의한 방법의 고조파 스펙트럼을 실험에 의하여 비교 검토하였다.

• Journal of Korea Water Resources Association
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• v.54 no.1
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• pp.49-60
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• 2021

This study presents a methodology to estimate two distinct fractal dimensions of natural river basin by using fractal tree concept. To this end, an analysis is performed on fractal features of a complete drainage network which consists of all possible drainage paths within a river basin based on the growth process of fractal tree. The growth process of fractal tree would occur only within the limited drainage paths possessing stream flow features in a river basin. In the case of small river basin, the bifurcation process of network is more sensitive to the growth step of fractal tree than the meandering process of stream segment, so that various bifurcation structures could be generated in a single network. Therefore, fractal dimension of network structure for small river basin should be estimated in the form of a range not a single figure. Furthermore, the network structures with fractal tree from this study might be more useful information than stream networks from a topographic or digital map for analysis of drainage structure on small river basin.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.12
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• pp.71-78
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• 2008

The paper proposes a chaotic double tent mapping PWM scheme for mitigation the acoustic noise of a motor chive. The chaos area ${\lambda}=0.99$ in bifurcation tree of the double tent mapping is used for generating the chaotic numbers. A 80C196 micro-controller is employed for generation of chaotic numbers, and the triangular carrier with chaotic frequency is obtained by using a 80C196 micro-controller and a MAX038 frequency modulator. The experiments are executed with a 1.5[kw] induction motor chive under the 2.5[A] load condition. As results, the experimental results show that the carrier, voltage and 3-D switching noise spectra of the proposed scheme is spread over the chaotic frequency range with no specific frequency concentration. Thereby, the shrill acoustic noise radiated from a motor chive is reduced by the proposed scheme.

• Korean Journal of Veterinary Research
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• v.6 no.1
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• pp.57-75
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• 1966

This study was conducted to observe the condition of the ramifications of the bronchus and pulmonary blood vascular system by injecting the vinylite into the bronchial tree and pulmonary blood vessels in 100 normal adult dogs. The results obtained were summarized as follows: 1. Lungs of dog were composed of the same pulmonary territories as in lungs of human. 2. Cardiac lobe corresponding to R.medio-bassalis of human lungs was well developed and situated as a independent cardiac lobe, in ventral side of right lung. 3. Bronchial tree were in the patterns of axial divergency and blood vascular systems were (in general) branched along the bronchial tree, arteries lying near the bronchial tree but veins apart from it. 4. Among the branching patterns of bronchus pulmonary artery and pulmonary vein in each lobe, the type presented most frequently were noted, which were designated basic type by the author. 5. Pulmonary blood vessels were not always branched in accordance with bronchial tree, diverged inmore complex patterns, especially in venous vascular system. 6. Ramus anterior (lobe apicalis) was always observed in all casting specimen. 7. There was a case of peculiar variation patterns of the ramification in the bronchi directing into the left apical and cardiac lobe, arose respectivelly, at independent origin of bifurcation in the left bronchial stem, and a case of peculiar variation pattern of the artery entering left apical lobe and cardiac lobe, had a same origin of the bifurcation at rami pulmonary artery, and then divided respectivelly into the rami medi artery and rami left apical lobe artery. 8. In the classification based on the patterns of bronchial and blood vasculor divergencys, there were a lot of significant combination cases in their patterns.

• Korean Journal of Head & Neck Oncology
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• v.13 no.2
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• pp.247-250
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• 1997

Bronchogenic cysts are thought to be uncommon developmental anomalies. They develop from small buds or diverticuli that separate from the foregut in the formation of the tracheo-bronchial tree. They are nearly always located near the tracheal bifurcation; However, these lesions can occur anywhere along the tracheo-bronchial tree. We experienced a case of cervical bronchogenic cyst presenting sorely as an anterior neck mass in a 26-year-old woman. The neck ultrasonography showed as $1.4{\times}1.1cm$ sized hypoechoic lesion with a well-defined margin on the isthmic portion of the thyroid gland. Excision of the mass was carried out. The mass was superfical to the strap muscle and was contained within the subcutaneous tissue in the midline without any connection to the trachea. Grossly, the mass was an oval-shaped cystic lesion which measured 1.5 cm in the greatest diameter. The cyst was filled with thick, yellow, jelly-like material and the inner surface was smooth and glistening. Microscopically, the cyst showed a lining of ciliated columnar epithelium, beneath which was a loose areolar stroma containing plaques of mucous glands and mature cartilage. We thought this cervical bronchogenic cyst appeared to represent an expression of complete aberrent accessory lung bud detachment from the primitive foregut.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.151-156
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• 2018

Because of its large differences in writing style, context-independency and high recognition accuracy requirement, free handwritten digital identification is still a very difficult problem. Analyzing the characteristic of handwritten digits, this paper proposes a new handwritten digital identification method based on combining structural features. Given a handwritten digit, a variety of structural features of the digit including end points, bifurcation points, horizontal lines and so on are identified automatically and robustly by a proposed extended structural features identification algorithm and a decision tree based on those structural features are constructed to support automatic recognition of the handwritten digit. Experimental result demonstrates that the proposed method is superior to other general methods in recognition rate and robustness.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.270-274
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• 2006

This paper proposes a Chaos Pulse Width Modulation(CPWM) technique. For generating the chaotic numbers by chaos phenomenon, chaos area $\lambda$=0.99 in bifurcation tree of the proposed double tent mapping is used. A micro-controller is used for the generation of chaos numbers and triangular carrier with chaotic frequency is obtained through the process of frequency modulation according to the generated chaos numbers. The experiments are executed with the 1.5kw induction motor coupled with a 2.5A load. The experimental results show that the voltage / current spectra are spread to a chaotic range, and the switching noise of motor is reduced by the proposed method compared to the fixed frequency PWM method.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.766-769
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• 2005

본 연구에서는 카오스 랜덤 캐리어 PWM에 의한 3상 유도 전동기의 스위칭 소음 저감에 대하여 다루고 있다. 랜덤 수 발생기로서는 종전부터 사용해 온 선형일치발생기(LCG)대신에 Logistic map의 분기트리를 사용하였다. 카오스 랜덤 수 발생은 80C196 마이크로 콘트롤러가 담당하고 있으며, 80C196으로부터 발생된 카오스 랜덤 수와 MAX038에 의하여 삼각파 랜덤 캐리어가 발생되고 있다. 1.5kw급 3상 유도전동기 구동 시스템에 카오스 랜덤 PWM와 종전의 방법을 적용하여 전동기 전압 및 전류 그리고 스위칭 소음의 스펙트럼을 고찰하였다.

• Journal of the korean academy of Pediatric Dentistry
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• v.21 no.2
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• pp.439-455
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• 1994

The purpose of this study was to investigate the distribution of nerves in the periodontal ligament of a dog's primary teeth by each developing stage. The distribution of nerves in the periodontal ligament were investigated by means of immunohistochemistry for detection of neurofilament protein (NFP). The results were as follows: The NFP-immunoreactive nerve fibers were found to be densely distributed in the apical third of the periodontal ligament, while they were sparse in the coronal two third, in both primary and permanent teeth. In generally the density of distribution and degree of arborization of nerve fibers in periodontal ligament of primary teeth revealed a poor appearance compared with that of permanent teeth. Periodontal ligament in anterior teeth showed more abundant nerve innervation than posterior teeth, and the periodontal ligament of the bifurcation area in posterior teeth roots were not observed to have nerve fiber. The density of nerve distribution in the periodontal ligament of primary teeth was reduced according to the physiological root resorption and nerve fibers were not observed in the surrounding area on the root of the exfoliation stage in primary teeth. The distribution of nerve fibers in mucogingival tissue, was poor innervated according to the aging of the dogs. A more abundant distribution of nerve fiber was represented in the lingual mucogingival tissue than in the labial side. Most of the nerve endings in the periodontal ligament of primary teeth showed a tree-like appearance. However, the typical Ruffini-like nerve endings were not observed.