• The korean journal of orthodontics
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• v.7 no.1
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• pp.7-11
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• 1977

The purpose of this study was to investigate the resorption potential in human permanent teeth by analyzing the frequency and the degree of root resorption as revealed by routine intraoral roentgenograms. The following conclusions were obtained: 1) The distribution of root resorptions was as follows; a) 65.3 per cent were no root resorption. b) 7.0 per cent showed questionable root shortening. c) 25.2 per cent were definite root shortening. d) 2.5 per cent showed very severe resorption. 2) The order of susceptibility of teeth to resorption in this study was consistent with other studies. 3) The maxillary teeth showed a much higher incidence (52.2 per cent) than the mandibular teeth (17.1 per cent) 4) The sex ratio of the sample in this study was 1.3 female to 1 male.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.372-375
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• 2003

The incidence of blindness resulting from diabetic retinopathy has significantly increased despite the intervention of insulin to control diabetes mellitus. Early signs are microaneurysms, exudates, intraretinal hemorrhages, cotton wool patches, microvascular abnormalities, and venous beading. Advanced stages include neovascularization, fibrous formations, preretinal and vitreous microhemorrhages, and retinal detachment. Microaneurysm count is important because it is an indicator of retinopathy progression. The purpose of this paper is to apply data mining to detect diabetic retinopathy patterns in routine fundus fluorescein angiography. Early symptoms are of principal interest and therefore the emphasis is on detecting microaneurysms rather than vessel tortuosity. The analysis does not involve image-recognition algorithms. Instead, mathematical filtering isolates microaneurysms, microhemorrhages, and exudates as objects of disconnected sets. A neural network is trained on their distribution to return fractal dimension. Hausdorff and box counting dimensions grade progression of the disease. The field is acquired on fluorescein angiography with resolution superior to color ophthalmoscopy, or on patterns produced by physical or mathematical simulations that model viscous fingering of water with additives percolated through porous media. A mathematical filter and neural network perform the screening process thereby eliminating the time consuming operation of determining fractal set dimension in every case.

• Journal of Preventive Medicine and Public Health
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• v.22 no.2 s.26
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• pp.197-207
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• 1989

This study was planned to investigate employer's attitude about health management of workers in coal mine industry. The sample size was 38.3% (178 coal mine industries) of total 463 coal mine industries. The mailing survey was used to collecting data of coal mine industry and manager of coal mine industry. Distribution of attitude about health management of workers in coal mine industry, specifically necessity and availability of some items of health management and some apparatus of working environment, was skewed to positive attitude. While recognition of susceptability of coal workers' pneumoconiosis was low, that of seriousness of incidence of coal workers' pneumoconiosis was high.

• Journal of Chest Surgery
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• v.15 no.2
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• pp.148-154
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• 1982

The experience with operative treatment for peripheral situated solitary circumscribed lesions of the lung at the Department of Thorac. & Cardiovasc. Surg., Korea University Hospital during 8 years from March 1974, through April, 1982 was reviewed. Our criteria for Solitary pulmonary nodule were 1. Round or Ovoid shape 2. Surrounded by normal lung Parenchyme 3. Well circumscribed peripheral location 4. No other visible pulmonary diseases on chest X-ray except minimal atelectasis or pneumonitis 5. Largest diameter less than 8 cm Of the 55 patients reviewed, there were 69% of malignancy and 31% of benign pulmonary diseases. In malignancy 38 patients, there were 18 patients with squamous cell carcinoma, 8 patients with undifferentiated large cell carcinoma, 2 patients with undifferentiated small cell carcinoma, 10 patients with adenocarcinoma and patient with metastatic carcinoma. In benign pulmonary nodule 17 patients, here were 5 patients with tuberculoma, 5 patients with aspergilloma, 2 patients with A-V fistula, 1 patient with pulmonary blastoma, 1 patient with paragonimiasis, and 1 patient with lung abscess. Overall male to female occurrence ratio was 39:16, and most prevalent age incidence was 7th decades. Most frequent size distribution was 4-6 cm in diameter. All of benign diseases were cured by resection and 66% of malignancy performed operation and has 75% resectability.

• Journal of Chest Surgery
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• v.28 no.11
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• pp.1019-1024
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• 1995

Clinical analysis were performed on 68 cases of subcutaneous emphysema, those were visited at the emergency center of Chosun university hospital during the period form 1992 to 1994. The following result was obtained. 1 The incidence of subcutaneous emphysema was 0.16%, and male was dominant [M:F=6.9:1 .2 The age distribution of subcutaneous emphysema was from 4 to 77 years old and mean age was 49.6$\pm$17.8 years[$\pm$SD 3 The most presenting symptoms were chest pain[49% , and the proceeding cause was traffic accident[38% . 3 The most associated disease was a ipsilateral pneumothorax[59% . 4 Conservative management is an indication in the majority of cases of subcutaneous emphysema because it is usually a self-limited condition and spontaneous remission usually occurs. We conclude that initial effort must be made to detect the underlying cause of the subcutaneous emphysema in order that appropriate management may be undertaken.

• Korean Journal of Health Education and Promotion
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• v.6 no.1
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• pp.60-65
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• 1989

A statistical analysis was made on 15,971 surgically operated patients at D-Medical Center in the year of 1978 and 1988. 1,416 cancer patients among them were classified by sex, age, and malignant tumor site. The obtained results indicated that trend of male cancer was generally similar to the results of nation wide study. But, specific phenomenon was found in the case of female cancer in Daegu-Kyungbuk area. Among females the frequency rank was uterine cervix (35.77%), breast (17.97%), stomach (11.65%) in 1988. The frequency of uterine cervix was higher than other area. Breast cancer was highly ranked tumor compare with other area, and its age distribution also appeared in much younger decade.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.6
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• pp.1281-1290
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• 2001

A study on the fluid flow with ultrasonic forcing is carried out to obtain data for the turbulence enhancement. A large water tank is made of the transparent acrylic plates and a horizontal flow field is given by setting two acrylic tubes to face mutually on a horizontal line. A 2-dimensional PlV system which is composed of a continuous-output 4W Argon-ion laser, a high-speed video camera, a PC based by an image grabber and a high resolution monitor is used to investigate characteristics of the complex turbulence flow field. And a 2MHz ultrasonic transducer is used fur ultrasonic vibration forcing. Some experiments are carried out at Reynolds numbers of 2,000 and 4,000 and at 7 angles of ultrasonic incidence. In results, the flew velocity vector distribution, kinetic energy and turbulence intensity in both cases of with and without ultrasonic forcing are examined, compared and discussed by using PIV measurement. It is clarified that the ultrasonic forcing into flow field is valid to obtain the turbulence enhancement.

• Journal of Chest Surgery
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• v.12 no.4
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• pp.307-311
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• 1979

Bronchogenic carcinoma with subcutaneous metastasis is rare, and the incidence ranged from 1.0 to 3.0 %. Therefore metastatic nodules are incidental findings in some instances. The distribution in order of frequency Is as follows: chest wall, scapular region, abdominal wall, course of spine, upper extremities and scalp etc, and mos. of nodules are between 0.5-2.0 cm in diameter. In this report, we present one case of a 54 year old male having bronchogenic carcinoma (squamous cell type) with multiple subcutaneous metastases. The metastatic nodules were located in subcutaneous tissue of right posterior chest wall ($4{\times}5$ cm), frontal scalp area (two; $2{\times}3$ cm, $0.5{\times}0.5$ cm), left scapular region ($1{\times}1$ cm) and left iliac crest ara ($1{\times}11$ cm).

• Advances in aircraft and spacecraft science
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• v.1 no.1
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• pp.27-41
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• 2014

An active flow control technique based on "smart-tabs" is proposed to delay flow separation on a circular cylinder. The actuators are retractable and orientable multilayer piezoelectric tabs which protrude perpendicularly from the model surface. They are mounted along the spanwise direction with constant spacing. The effectiveness of the control was tested in pre-critical and in post-critical regime by evaluating the effects of several control parameters of the tabs like frequency, amplitude, height, angular position and plate incidence with respect to the local flow. Measurements of the mean static pressure distribution around the cylinder were used to estimate the pressure drag coefficient. The maximum drag reduction achieved in the pre-critical regime was of the order of 30%, whereas in the post-critical regime was about 10%, 3% of which due to active forcing. Furthermore, pressure fluctuation measurements were performed and spectral analysis indicated an almost complete suppression of the vortex shedding in active forcing conditions.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.13 no.1
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• pp.145-150
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• 1983

The author studied clinically and radiologically 55 cases which had been diagnosed as odontoma in SNUDH. The obtained results were as follows: 1. In sex distribution, there was no prevalence in both sexes. And the incidence was the highest in the 2nd decade. (16 patients, 29%) 2. There were 42 cases of compound odontoma (76%) and 13 cases of complex odontoma (24%). In most cases, compound odontoma was located at the anterior portion (34 cases, 81%) and complex odontoma at the posterior portions (9 cases, 69%). 3. There was no apparent clinical symptom in compound odontoma (83%), but in complex odontoma, 80% of case show swelling. 4. The adjacent root resorption was not observed in any case. 5. Five cases radiographically diagnosed as cystic odontoma were not confirmed histopathologically.