Biomedical subjects

Byung Cheol Song

Publications and source records attributed to Byung Cheol Song.

3 recordsLinked to original sources

PubMed2005

A rate-constrained fast full-search algorithm based on block sum pyramid.

This paper presents a fast full-search algorithm (FSA) for rate-constrained motion estimation. The proposed algorithm, which is based on the block sum pyramid frame structure, successively eliminates unnecessary search positions according to rate-constrained criterion. This algorithm provides the identical estimation performance to a conventional FSA having rate constraint, while achieving considerable reduction in computation.

Algorithms↗

PubMed2003

Airway obstruction after acute ozone exposure in BALB/c mice using barometric plethysmography.

BACKGROUND: Airway responsiveness after acute inhalation of ozone is related to the concentration and duration of ozone exposure. Using barometric whole-body plethysmography and increase in enhanced pause (Penh) as an index of airway obstruction, we measured the response of BALB/c mice to acute ozone inhalation to study the time course change of pulmonary function after ozone exposure. METHODS: Penh was measured before and after exposure to filtered air or 0.12, 0.5, 1, or 2 ppm ozone for 3 hr (n = 6/group). In addition, Penh was measured 24, 48 and 72 hr after ozone exposure. Bronchoalveolar lavage (BAL) and histopathologic examinations were performed. RESULTS: The increase in Penh after ozone exposure was significantly higher in the 0.12, 0.5, 1 and 2 ppm groups compared with the control group (all p < 0.01). Increases in Penh 24 hr after ozone exposure were significantly lower than those immediately after acute ozone exposure; however, increases in Penh 72 hr after ozone exposure were significantly higher than those in the control group (each p < 0.01). The proportion of neutrophils in BAL fluid was significantly higher in the group exposed to 2 ppm ozone than in the groups exposed to filtered air or 0.12 ppm ozone (both p < 0.01). CONCLUSION: These results indicate that airway obstruction is induced following ozone exposure in a concentration-dependent manner and persists for at least 72 hr.

Airway Obstruction↗

PubMed2002

[Validation of international autoimmune hepatitis group scoring system for diagnosis of type 1 autoimmune hepatitis in Korea].

BACKGROUND/AIMS: There are no pathognomonic features of autoimmune hepatitis (AIH). Its diagnosis requires the exclusion of various other conditions. The aim of this study was to validate indirectly the International Autoimmune Hepatitis Group (IAHG) scoring system in diagnosing AIH. METHODS: Twenty-six patients with Type 1 AIH and female patients with chronic hepatitis B (n=34), chronic hepatitis C (n=25), or toxic hepatitis (n=13) were evaluated according to 9 categories of pretreatment minimum required parameters proposed by IAHG. Aggregate scores of AIH to those of non-AIH groups, which were assessed before and after extracting the proportions of etiologic factors, were also compared and evaluated. RESULTS: While aggregate scores of non-AIH groups, before extracting the proportions of etiologic factors, were 5.2+/-1.8, 5.6+/-1.1, and 7.4+/-1.2 in that order, those of AIH groups were 12.8+/-1.7. These were significantly higher than those of non-AIH groups (p<0.01). All patients in AIH groups and only 1 patient in a non-AIH group showed aggregate scores of more than 10. Aggregate scores after extracting the proportions of etiologic factors were more than 4 in all, except 2, patients. These should have been consistent with 10 if there were no etiologic factors in non-AIH groups. CONCLUSION: The IAHG scoring system might have a relatively excessive importance to the scores of categories excluding distinct etiologies from AIH. It might be difficult to differentiate AIH from chronic liver diseases of indistinct cause based on the IAHG scoring system.

Adult↗