영양과 면역

백지선 연세대학교 생활과학대학 1990 婦學 Vol.23 No.-

The effects of voltage of x-ray tube on fractal dimension and anisotropy of diagnostic image

백지선,이삼선,박관수,허경회,이원진,허민석,최순철 대한영상치의학회 2007 Imaging Science in Dentistry Vol.37 No.4

Purpose: The purpose of this study was to evaluate the effect of the kV on fractal dimension of trabecular bone indigital radiographs.Materials and Methods: 16 bone cores were obtained from patients who had taken partial resection of tibia due toaccidents. Each bone core along with an aluminum step wedge was radiographed with an occlusal film at 0.08 secand with the constant film-focus distance(32cm). All radiographs were acquired at 60, 75, and 90kV. A rectangu-lar ROI was drawn at medial part, distal part, and the bone defect area of each bone core image according to eachkV. The directional fractal dimension was measured using Fourier Transform spectrum, and the anisotropy wasobtained using directional fractal dimension. The values were compared by the repeated measures ANOVA. Results: The fractal dimensions increased along with kV increase(p0.05). The anisotropy measurements did notshow statistically significant difference according to kV change. The fractal dimensions of the bone defect areas ofthe bone cores have low values contrast to the non-the bone defect areas were lower than those of the non-defect areas of the bone cores, but not statistically signifi-cant.Conclusion : Fractal analysis can notice a difference of a change of voltage of x-ray tube and bone defect or not.And anisotropy of a trabecular bone is coherent even with change of the voltage of x-ray tube or defecting off a partof bone. (Korean J Oral Maxillofac Radiol 2007; 37 : 211-5)

Effect of the Introduction of High-speed Trains on Consumer Welfare

백지선 한국개발연구원 2016 KDI Journal of Economic Policy (KDI JEP) Vol.38 No.1

This paper examines the impact of introducing high-speed trains on consumer welfare, taking the ensuing changes in train schedules into account. Based on the estimated demand model for travel which incorporates consumer’s heterogeneous preferences for travel schedules into the standard discrete-choice model, I separately evaluate the impact from adding high-speed trains and that from changes in train schedules. The results indicate that consumers who travel between two cities connected by high-speed trains benefit from the introduction of high-speed trains, while some travelers whose choice set does not include high-speed trains face a reduced frequency of non-high-speed trains, resulting in significant losses.

Frontoethmoidal Mucocele Presenting as Progressive Enophthalmos

백지선,김수환,양석우 대한안과학회 2012 Korean Journal of Ophthalmology Vol.26 No.3

In this case report we describe a 27-year-old man who presented with progressive enophthalmos for 5 months without any other associated ocular symptoms such as pain, diplopia, or visual disturbance. Computed tomography showed that his progressive enophthalmos originated from a frontoethmoidal mucocele and this caused destruction of the lamina papyracea and shrinkage of the ethmoidal air cell. Finally the enlarged orbital space caused an inward deviation of the eyeball. Endoscopic marsupialization was successfully performed by an otolaryngologist and did not result in any ophthalmologic sequelae. Although frontoethmoidal sinus mucoceles mostly frequently originates from orbital mucoceles, enophthalmic manifestations are very rare. Enophthalmic conditions are not as responsive to surgical interventions as exophthalmic conditions.

The diagnosis of coronoid impingement using computed tomography

백지선,허경회,박관수,박무순,허민석,이삼선,최순철 대한영상치의학회 2005 Imaging Science in Dentistry Vol.35 No.4

Coronoid impingement can cause limitation of mouth opening. In many cases, it appears to be related to thecoronoid hyperplasia. We present a case of mouth opening limitation caused by coronoid impingement on theposterior surface of the zygomatic bone without coronoid hyperplasia. The bony changes in coronoid and zygoma including surface irregularity and discontinuity of the cortex and sclerotic change of inner medullary space were noted on computed tomography (CT) scans in different level of axial planes. Through another CT scans in open mouth position could demonstrate that those bony changes were caused by the contact of both surfaces against each other. In case coronoid impingement is suspected of the many possible causes, the open mouth CT scans will be needed to reveal the direct impingement of coronoid on zygoma even without coronoid hyperplasia.

Quarternized Ammonium bromide 를 가지는 Methacrylate 중합체의 감습 성질

백지선,김태미,공명선 한국고분자학회 1994 한국고분자학회 학술대회 연구논문 초록집 Vol.1994 No.4

코로나19 발생 이후 사업체의 매출 변화와 이의 지역 간 차이

백지선 한국응용경제학회 2022 응용경제 Vol.24 No.2

본 논문은 BC카드사의 신용카드 지역(동)별 매출 데이터를 이용하여, 코로나19 이후 사업체의 매출 변화는 각 지역별로 다르게 나타나며, 해당 변화의 지역 간 이질성은 업종별로 다를 수 있음을 밝혔다. 주거 기능이 밀집된 지역의 경우 코로나19 유행 이후 신용카드 가맹점의 피해가 상대적으로 적었으며, 업무 기능 혹은 상업 기능이 밀집된 지역은 그 피해의 규모가 컸다. 또한, 지역별 특성변수와 지역별 매출 변화의 상관관계는 업종별로 상이한 것으로 나타났다. 유통업, 일반음식, 음식료품 등의 업종에서는 매출변화와 지역별 특성변수가 통계적으로 유의미한 상관관계가 있었으나, 내구재 업종 등의 매출은 지역별 특성과 상관관계가 나타나지 않았다. 1차 확산기에 집단감염이 발생했던 레저업소나 방역 조치의 직접적 규제의 대상이었던 유흥주점의 매출은 지역별 특성과 상관관계를 보이지 않았다.

병행적 혼합조사의 모드효과 분석

백지선,민경아,Baek, Jeeseon,Min, Kyung A 한국통계학회 2016 응용통계연구 Vol.29 No.5

사회환경 변화와 정보기술 발전에 따라 한 조사에 다양한 조사모드(survey mode)를 활용하는 혼합조사(mixed-mode survey)가 확대되고 있으며, 포함오차 축소, 비용절감, 응답률 향상 등의 장점을 가진다. 그러나 혼합조사는 선택효과와 측정효과가 혼재된 모드효과 발생으로 조사품질에 대한 우려가 있다. 통계개발원은 이러한 혼합조사의 모드효과를 파악하기 위하여 2014년에 병행적 혼합모드 시험조사를 수행하였다. 본 연구는 시험조사 자료에 대해 자기기입식 종이조사와 웹조사 간 모드효과를 선택효과와 측정효과로 분리하여 계량적으로 분석하였다. 선택계층의 효과를 분리하였을 때, 조사항목에 따라 과대 또는 과소 응답하는 측정효과가 존재하는 것을 확인하였다. Mixed-mode (MM) designs in which data are collected by different modes in one design have become increasingly popular. An MM data collection has several advantages such as reductions of coverage error, non-response and cost. However, MM designs may introduce mode effects that are confounded by selection effects and measurement effects, which can make MM data quality poor. In order to investigate mode effects, SRI implemented a concurrent mixed-mode experiment in 2014 where respondents could choose between a self-administrated Web survey and a self-administrated paper survey. This paper separately estimates selection effects and measurement effects. We found that measurement effects on some items are large.

한국인 갑상샘눈병증 환자의 기분상태 조사

백지선,양석우 대한안과학회 2009 대한안과학회지 Vol.50 No.9

Purpose: to measure mood disturbance of Korean patients with dysthyroid ophthalmopathy according to the severity of ophthalmopathy. Methods: Fifty patients with dysthyroid ophthalmopathy (mean age: 46.6±12.1 years; 32 female patients and 18 male patients) were included, and classified into 2 groups according to the disease severity. Twenty-five patients were classified with moderate/severe diseases (study group) and 25 patients classified with negligible/mild disease (control group). All patients completed a mood survey of 65 questions to assess differences in the degree of emotional distress. Results: Analysis of each group showed that patients with moderate/severe ophthalmopathy had significantly greater emotional distress than patients with negligible/mild ophthalmopathy according to the Korean Profile of Mood States mean total score (p=0.03). In particular, patients with disfigurement (proptosis predominant group) had significantly worsen emotional distress compared with the control group (p=0.007), whereas patients with diplopia (diplopia predominant group) had no significant difference compared with the control group (p=0.60). Conclusions: Patients with moderate to severe ophthalmopathy have significant emotional distress, and severe mood disturbance especially when disfiguring signs are predominant. The psychological burden of the disease should be recognized, and routine follow-up recommended along with additional psychiatric consultation. 목적: 갑상샘눈병증 환자에서 증상의 정도와 종류에 따른 기분상태의 변화를 알아보고자 한다. 대상과 방법: 갑상샘눈병증 환자 50명(평균 연령: 46.6±12.1세, 여자: 32명, 남자: 18명)을 증상의 정도에 따라 중등도/중증 집단과 경미/경증 집단의 두 군으로 분류하여 모든 대상에 대하여 65문항의 설문조사를 시행하여 감정적 고통의 정도를 평가하였다. 결과: 증상의 정도가 중등도/중증으로 분류된 집단이 경미/경증으로 분류된 집단보다 더 심한 감정적 고통을 호소하였다(p=0.03). 중 등도/중증 집단에서 안구돌출을 주증상으로 보인 환자군에서 대조군과 비교 시 심한 감정적 괴로움을 호소하였으며(p=0.007), 복시 증상을 주로 보인 환자군에서는 대조군과 비교시 유의한 차이를 보이지 않았다(p=0.60). 결론: 중등도 이상의 심한 갑상샘눈병증 환자에서는 유의한 감정의 고통을 호소할 수 있고 유의한 우울증상을 경험할 수 있으므로 이에 대한 고려와 함께 정기적 추적관찰을 통해 정신과적 심리치료의 시기를 놓치지 않도록 유의하여야 한다.

왕따에게는 관심이 필요하다

백지선 우리신학연구소 2011 갈라진 시대의 기쁜소식 Vol.- No.965