• Journal of the Korea Society of Computer and Information
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• v.12 no.3
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• pp.177-183
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• 2007

Active queue management (AQM) refers to a family of packet dropping mechanisms for router queues that has been proposed to support end-to-end congestion control mechanisms in the Internet. The proposed AQM algorithm by the IETF is Random Early Detection (RED). The RED algorithm allows network operators simultaneously to achieve high throughput and low average delay. However. the resulting average queue length is quite sensitive to the level of congestion. In this paper, we propose the Refined Adaptive RED(RARED), as a solution for reducing the sensitivity to parameters that affect RED performance. Based on simulations, we observe that the RARED scheme improves overall performance of the network. In particular, the RARED scheme reduces packet drop rate and improves goodput.

• Tuberculosis and Respiratory Diseases
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• v.43 no.3
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• pp.455-460
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• 1996

In general, a bulla of the lung is large, air contained sac and it is more than 1cm in diameter, and its wall is well defined and less than 2mm thick. The natural course of bulla of the lung is said to follow a pattern of progressive deterioration. It is a progressive disease, and spontaneous resolution of bulla is very unusual. In the world only two cases of spontaneous resolution of bulla have been reported. We experienced a case of bullous lung disease complicated from miliary tuberculosis in which the bulla was disappeared spontaneously following bulla infection.

• Tuberculosis and Respiratory Diseases
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• v.47 no.1
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• pp.35-41
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• 1999

Background: Sleeve lobectomy of the main bronchus has been proposed to spare lung tissue in patients who cannot tolerate pneumonectomy because of impaired lung function. The purpose of this study was to evaluate whether sleeve lobectomy can preserve lung function as expected from preoperative evaluation of lung function in patients with non-small cell lung cancer. Method: Between January 1995 and March 1998, 15 patients with non-small cell lung cancer who underwent sleeve resection were evaluated. Preoperative evaluations included spirometry and quantitative lung perfusion scan, from which predicted postoperative $FEV_1$ was calculated. At least 3 months after operation follow up spirometry and bronchoscopy were performed. Predicted FEVj was compared with measured postoperative $FEV_1$. Result: Fourteen men and one woman, with median age of 58 years, were reviewed. The diagnosis was squamous cell carcinoma in 13 patients and adenocarcinoma of lung in 2 patients. Our results showed a excellent preservation of pulmonary function after sleeve lobectomy. Correlation between the predicted (mean, $2180{\pm}570mL$) and measured $FEV_1$ (mean, $2293{\pm}499mL$) was good(r=0.67, P<0.05). Furthermore, patient with low $FEV_1$ (<2L) showed improved lung function after sleeve lobectomy. Conclusion: These findings indicated a complete recovery of the reimplanted lung lobes after sleeve lobectomy. Therefore, this technique could be safely used in lung cancer patients with impaired lung function.

• Tuberculosis and Respiratory Diseases
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• v.57 no.5
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• pp.484-488
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• 2004

In adults, aspiration of foreign bodies into tracheobronchus is sometimes presented atypically, mimicking chronic pulmonary diseases such as bronchial asthma, pneumonia, or empyema, especially without notice of aspiration or choking. In such cases, diagnosis and adequate treatments are often delayed. Suspicion of foreign body aspiration and computed tomography and bronchoscopic examination make correct diagnosis more early. We report a case of bronchial foreign body, which had been misdiagnosed as bronchial asthma with wheezing in the whole lung filed, and reversible airway obstruction in the spirometry.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.4
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• pp.34-43
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• 2010

Texture information plays an important role in object recognition and classification. To perform an accurate classification, the texture feature used in the classification must be highly discriminative. This paper presents a novel texture descriptor for texture-based image retrieval and its application in Computer-Aided Diagnosis (CAD) system for Emphysema classification. The texture descriptor is based on the combination of local surrounding neighborhood difference and centralized neighborhood difference and is named as Combined Neighborhood Difference (CND). The local differences of surrounding neighborhood difference and centralized neighborhood difference between pixels are compared and converted into binary codewords. Then binomial factor is assigned to the codewords in order to convert them into high discriminative unique values. The distribution of these unique values is computed and used as the texture feature vectors. The texture classification accuracies using Outex and Brodatz dataset show that CND achieves an average of 92.5%, whereas LBP, LND and Gabor filter achieve 89.3%, 90.7% and 83.6%, respectively. The implementations of CND in the computer-aided diagnosis of Emphysema is also presented in this paper.

• Tuberculosis and Respiratory Diseases
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• v.49 no.6
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• pp.752-759
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• 2000

Background : Many studies have shown that pulmonary function differs widely among race, age and geographical residency. By virtue of the improvement of nutrition and environment, the elderly population in Korea is markedly increasing and so are the ages of patients complaining respiratory symptoms. However, we do not have our own data on the pulmonary functional reserve of elderly persons in Korea. We evaluate the deterioration of pulmonary functional reserve and standardize the predictive values of pulmonary function in the elderly population. Method : Pulmonary function tests were conducted in 100 men and 100 women over the age of 65. We analyzed changes of FVC and $FEV_1$ according to age and height by linear regression. We compared our new multiple linear regression equation with other equations currently used in Korea. Results : In men, the mean age was $71.5{\pm}5.2$(mean${\pm}$SD) years and the mean height was $163.6{\pm}6.2$cm. The mean FVC was $3.42{\pm}0.49{\ell}$ and the mean $FEV_1, $2.72{\pm}v$. In women, the mean age was $72.0{\pm}5.1$ years and the mean height was $149.1{\pm}5.9$cm. The mean FVC was $2.22{\pm}0.42{\ell}$ and the mean $FEV_1$ $1.83{\pm}0.34{\ell}$. Multiple linear regression equation using age and height as an independent factors was as follows : FVC(${\ell}$)=1.857-0.0356$\times$age(year)+0.02517$\times$height(cm) (p<0.01, $R^2$=0.279), $FEV_1(${\ell}$)=1.340-0.02698$\times$age(year)+0.02021$\times$height(cm) (p<0.01, $R^2$=0.255) in men, FVC(${\ell}$) =-0.09765-0.03332$\times$age(year)+0.03164$\times$height(cm) (p<0.01, $R^2$=0.435), $FEV_1(${\ell}$)=-0.l69-0.02469$\times$age(year)+0.02539$\times$height(cm) (p<0.01, $R^2$=0.41) in women. Conclusion : We established prediction regressions for pulmonary functional tests in the elderly Korean population. We also confirmed that currently adopted equations do not exactly anticipate the expected pulmonary functional reserve in the aged person over 65 years old. We suggest that our new equations from this study should be applied to interpret the pulmonary function tests in the elderly population in Korea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.905-909
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• 2002

This study was peformed to determine the anticarcinogenic activity of the Solanum tuberosum Peel (SP) on several microorganisms and human cancer cell lines. Among the various solvent fractions of SP, the ethylether Partition layer (SPMEE) showed the strongest antimicrobial activity, ethylacetate partition layer (SPMEA) and butanol partition layer (SPMB) resulted in good antimicrobial activity. We also determined the effect of SP extract and fractions on cytotoxicity, and chemopreventive effect on human cancer cells. The experiment was conducted to determine cytotoxicity of SP partition layers on HepG2, HeLa and MCF-7 cells by MTT assay. Among the various partition layers of SP, SPMEE and SPW were showed the strongest cytotoxic effects on all cancer cell lines. The quinone reductase induced activities of HepG2 cell, the butanol partition layer (SPMB) at a does of 40 $\mu\textrm{g}$/mL was 8.49 times more effective compared to the control value of 1.0. This value was significantly higher than that of previous results using the other materials. Therefore, based on these studies, SP may be developed into a potentially useful antimicrobial and anticarcinogenic agents.

• Tuberculosis and Respiratory Diseases
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• v.42 no.4
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• pp.548-554
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• 1995

Background: Cardiogenic pulmonary edema increases nonspecific airway responsiveness in humans and animals. Increased extravascular lung water from overt pulmonary edema to subclinical interstitial edema is a common finding in patients with chronic renal failure. Several studies carried out to assess pulmonary function disturbances in this condition have documented a reduction in forced expiratory volume that usually reverses after hemodialysis, suggesting airway edema as the underlying mechanism. This interstitial edema may also lead to nonspecific bronchial hyperresponsiveness. We hypothesized that patients with chronic renal failure may present nonspecific bronchial hyperresponsiveness due to subclinical interstitial pulmonary edema. Methods: We studied 18 chronic renal failure undergoing regular hemodialysis 3 times a week(New York Heart Association Class II) without concomittent disease. These patients were checked pulmonary function test and metacholine provocation test before hemodialysis and same procedure was repeated if responsive, after hemodialysis. Results: 1) 12 out of 18 patients before hemodialysis were reactive in metacholine provocation test(66.7%) before hemodialysis. This airway hyperresponsiveness were decreased after hemodialysis. 2) Pulmonary function was improved after hemodialysis and change in $FEV_1$ was correlated with change in weight(r=-0.62, p<0.01). 3) There was a close correlation between log $PD_{20}$ and $FEF_{25}$, which is one of the variables of the peripheral airways(r=0.58, p<0.05). Conclusion: We speculated interstitial pulmonary edema may play a significant role in bronchial hyperresponsiveness and lung function impaired in patients with chronic renal failure.

• Tuberculosis and Respiratory Diseases
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• v.44 no.4
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• pp.806-814
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• 1997

The incidence, type and distribution of polyneuropathy in patients with chronic obstructive pulmonary disease (COPD) were assessed and also analyzed the causative factors. Forty-four patients, mean age 66.1 years (42 male, 2 female), have been investigated with arterial gas analysis, pulmonary function test, clinical and electrodiagnostic studies. None of them had conditions known to affect the peripheral nervous system such as metabolic disorders or drugs. In a selected group of 44 patients, electrophysiological findings of polyneuropathy were found in 22 patients(50%), clinical polyneuropathy were diagnosed in 13 patients(9 patients were diagnosed by electrophysiological studies, 4 patients were normal by electrophysiological studies). These findings indicate that subclinical polyneuropathy(13 patients, 30%) more commonly occurs than clinical polyneuropathy(9 patients, 20%) in associated with COPD. In the patients with polyneuropathy, the lesions were predominant axonal degeneration, the changes were more involved in leg than arm, more frequently affected sensory fibers. We could not find etiologic factor to cause polyneuropathy in COPD patients.

• Journal of the Korea Organic Resources Recycling Association
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• v.1 no.1
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• pp.103-113
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• 1993

Every year, over $3.37{\times}10^7$ ton of municipal solid waste is generated in Korea, of which about 28% is organic food waste from restaurant, dining halls and households etc. Methane conversion of the food waste by anaerobic digestion could be a viable approach for energy recovery as well as safe disposal of the waste. However, as food waste is composed of highmolecular complex polymers such as cellulose, lignin and protein, anaerobic digestion of food waste has not been efficient in terms of volumetric loading rate, solid retention time and extent of anaerobic degradation. In this research, the improved anaerobic degradation of food waste was attemped by applying rumen microorganisms to anaerobic digestion. Acidification efficiency of food waste by rumen microorganisms was compared with that of conventional acidogenesis. And optimum acidification conditions by rumen microorganisms were also determined. For the experiments, anaerobic batch reactors of 600 mL was fed with the processed (dried and milled) food waste obtained from a restaurant. Ultimate volatile fatty acid (VFA) yield produced by rumen microorganisms was about 8.4 meq VFA/g volatile solid (VS) that is 95% of the theoretical value. This yield was not much different from that of conventional acidogenesis, but hydrolysis rate was about twice faster. Cumulative VFA concentration increased from 66 meq/L to 480 meq/L, when the initial TS was increased from 1% to 15%. But VFA yield at 15% TS was half of that at 1% TS. This inhibition on the acidification might be caused by the rapid drop of pH and higher concentration of nonionized VFA. Optimal pH and temperature range for the acidification were about 6.0~7.5 and $35{\sim}45^{\circ}C$, respectively.