The Longitudinal Trend of Cardiac Surgery in Korea from 2003 to 2013

Lee, Kyeong Soo,Kim, Chang Suk,Park, Jong Heon,Hwang, Tae Yoon,Kim, Sang Won,Sim, Sung Bo,Lee, Kun Sei The Korean Society for Thoracic and Cardiovascular 2016 The Korean Journal of Thoracic and Cardiovascular Vol.49 No.sup

Background: The purpose of this study was to investigate longitudinal changes of the utilization of operational and surgical medical care inside and outside a metropolitan area over 10 years, analyzing the residential areas of patients and the locations of medical facilities for major cardiovascular surgery. Methods: Data analysis was conducted by classifying the addresses of patients and the locations of medical care facilities of metropolitan cities and provinces, using data from the National Health Insurance Corporation from January 2003 to December 2013. Results: There is serious concentration of major heart surgery to medical facilities in Seoul; this problem has not improved over time. There were differences in percentages of surgical procedures performed in the metropolitan areas according to major diseases. In the case of Busan and Daegu provinces, at least 50% of the patients underwent surgery in medical facilities in the city, but there are other regions where the percentage is less than 50%. In the case of provinces, the percentage of surgical procedures performed in medical facilities in Seoul or nearby metropolitan cities is very high. Conclusion: Policies to strengthen the regional capabilities of heart surgery and to secure human resources are required to mitigate the concentration of patients in the capital area. Many regional multi-centers must be designated to minimize unnecessary competition among regional university hospitals and activate a win-win partnership model for medical services.

원통 연삭에서 가공 능률 향상을 위한 연삭 저항의 측정에 관한 연구

김원일,이진,이윤경,왕덕현,이상복,이관철,문원길 경남대학교 공업기술연구소 2000 硏究論文集 Vol.18 No.-

본 연구에서는 원통 연삭 가공에서 가공 능률 향상을 위한 연삭 저항을 측정하고자 연삭 가공 중에 발생하는 연삭 저항의 추이를 확인하였고 다음과 같은 결과를 얻었다. 숫돌과 공작물간의 연삭 강성은 공작 속도의 증가에 따라 지지계의 강성이 높은 경우 증가하였고 절삭 깊이와 연삭 숫돌의 속도에는 연삭 강성이 감소하는 경향을 보였다. 또한 총합 강성은 공작 속도, 절삭 깊이 및 연삭 숫돌의 속도 증가에 따라 지지계의 강성이 높을 수록 증가하였다. 연삭기의 강성 변형과 가공 능률에 영향을 주는 값으로 연삭 강성비는 지지계의 강성이 높을 수록 감소하였다. In this study, the measurement of grinding resistance to improve grinding efficiency in cylindrical grinding was studied and the following conclusions could be obtained. Relation grinding wheel and workpiece, grinding stiffness increases according to increase of work speed for high machine stiffness and decreases depth of cut and grinding wheel speed. Also, resultant stiffness increases high machine stiffness according to increase work speed, depth of cut and grinding wheel speed. The values of the effect stiffness deflection in grinding machine, grinding stiffness ratio decrease according to high machine stiffness.

조선후기 천문학자 이덕성의 생애와 천문활동

안영숙,민병희,서윤경,이기원,AHN, YOUNG SOOK,MIHN, BYEONG-HEE,SEO, YOON KYEONG,LEE, KI-WON 한국천문학회 2017 天文學論叢 Vol.32 No.2

The life and astronomical activity of Lee Deok-Seong (李德星, 1720-1794) was studied using various historical sources, including the astronomical almanac, Seungjeongwon-Ilgi (Daily records of Royal Secretariat of Joseon dynasty), and the Gwansang-Gam's logbooks during Joseon dynasty (A.D. 1392-1910). We present the results of the study including the following main findings. First, from the investigation of Lee's family tree, we find that a number of his relatives were also astronomers, notably Samryeok-Gwan (三曆官, the post of calendrical calculation). Second, we find that he took part in the compilation of an annual astronomical almanac over a period of at least 16 years. His major achievements in the astronomy of the Joseon dynasty were to establish a new method of calendar-making calculation and to bring astronomical materials to the Joseon court through a visit to China. The Joseon dynasty enforced the Shixianli (時憲曆, a Chinese calendar made by Adam Shall) in 1654 without fully understanding the calendar. So an astronomer and an envoy were dispatched to China in order to master the intricacies of the calendar and to learn as much of Western science as was available in that time and place. Lee Deok-Seong worked at the Gwansang-Gam (觀象監, Royal Astronomical Bureau) during the reigns of King Yeongjo (英祖) and Jeongjo (正祖). As best as we can ascertain in relation with the calculations in the Shixian calendar, Lee visited China four times. During his trips and interactions, he learned a new method for calendar-making calculations, and introduced many Western-Chinese astronomical books to Joseon academia. Lee greatly improved the accuracy of calendrical calculations, even while simplifying the calculation process. With these achievements, he finally was promoted to the title of Sungrok-Daebu (崇祿大夫), the third highest grade of royal official. In conclusion, history demonstrates that Lee Deok-Seong was one of the most outstanding astronomers in the late-Joseon dynasty.

超硬 切斷工具 刃先의 應力分布 解析에 관한 硏究 (I)

李允景,金元鎰 慶南大學校 附設 工業技術硏究所 1987 硏究論文集 Vol.5 No.-

旋削에 의한 超硬 切斷工具의 傾斜面 應力 變形率 分布에 대한 靜剛性 解析을 한 結果 다음과 같은 結論을 얻었다. 切斷加工에서 切削깊이 方向의 切削速度 變化는 切削力에 큰 영향을 주지 않으며, 切削條件에 의한 應力, 變形率 變化는 移送이 클수록 크고 接觸길이 0.3㎜ 정도에서 應力 값이 크게 減少하므로 칩핑 가능성이 높다. 應力 및 變形率의 變化幅이 큰 것은 切削에 있어서 摩擦의 狀態가 칩 傾斜面 接觸길이 部分에서 一定하지 않는다는 것을 알았다. In the turning, Analyses of the static deformation relating to the destributions of stress and strain on a rake face of cemented carbide parting tool have obtained results which are as follows, 1. In the parting work, the change of cutting speed relating to cutting depth and direction has been greatly uneffected cutting force. 2. As feed grows larger, the change of stress and strain under cutting conditions grows larger, and the value of stress decreases greatly in the near contect length of 0.3㎜. therefore, It is highly possible thet chipping occurs. 3. In the cutting, the changed value of strain and stress which is large have been not uniformed the state of friction in the near contect length of Chip-rake face.

축하중과 첨가질량이 작용하는 적층복합판의 진동해석

이봉학,김경진,원치문,성기태 江原大學校 産業技術硏究所 1995 産業技術硏究 Vol.15 No.-

A method of calculating the natural frequency corresponding to the first mode of vibration of beams and tower structures, with irregular cross-sections and with arbitrary boundary conditions was developed and reported by D. H. Kim in 1974. IN this paper, hte result of application of this method to the laminated plates with axial forces and with attached point mass/masses is presented. Both N? and N? forces are considered. The solution for the laminated plates with arbitrary boundary conditions and irregular section can be obtained by simply obtaining the deflection influence coefficients by any method. The effect of neglecting the mass of the plates on the natural frequency, as the ratio of the point mass/masses to the plate mass increases, is thoroughly studied. The influence of N? and N? is also carefully investigated.

만경강 상류 수질 및 식생분포와 토양환경에 따른 하천식생의 종 다양성

이경보,김창환,이덕배,김종구,박찬원,나승용 한국환경농학회 2003 한국환경농학회지 Vol.22 No.2

만경강 상류유역 수질 및 하천식생 군락 변화를 조사 분석하여 수질에 따른 하천식생의 종 다양성 및 토양요인에 따른 종 다양성의 변화를 평가하기 위하여 2001년 6월부터 2002년 9월까지 만경강 상류유역 5개 조사지점을 선정한 후 조사를 실시하였다. 수질중 T-N의 농도는 전주천과 삼천에서 높았으며, 겨울철에 전주천에서 7.45 mg/L로 가장 높았다. 무기태 질소 성분벽 함량은 NH₄-N 경우 고산천과 소양천 유역은 0.01~0.06 mg/L 범위로 계절별 커다란 차이가 없는 낮은 농도를 나타냈으나, 생활하수가 유입되는 전주천과 삼천에서는 0.77~3.01 mg/L로 계절별로 큰 차이를 보였다. T-P의 농도는 계절별로 비슷하였으나 전주천에서 겨울천에 0.89 mg/L로 가장 높았다. 계절별 BOD의 농도는 고산천과 소양천 유역에서 0.92~2.14 mg/L를 나타내었으나 생활하수가 유입되는 유역에서는 2.01~7.65 mg/L범위를 보였다. SO₄²^(-)의 농도는 농업용수 수질기준인 50 mg/L를 초과하는 지역은 없었으며 소양천에서 다소 높았다. 만경강 지류인 고산천에서 조사된 식물은 59과 과 129속 165종 20변종으로 총 185종류가 조사되었으며, 소양천에서 조사된 식물은 53과 111속 141종 19변종으로 총 160종이었고, 전주천 하류에서 조사된 식물은 37과 68속 86종 15변종으로 총 103종이었다. 그리고 삼천에서 조사된 식물은 32과 92속 110종 18변종으로 총 128종류 조사되었으며, 만경강 본류인 하리유역에서 조사된 식물은 73과 134속 218종 33변종으로 총 251종류가 조사되었는데 식물의 생활형에 따라 분류하면 침수식물이 13종, 부엽식물이 5종, 부유식물이 2종, 추수식물이 26종, 수생식물이 46종, 습생식물이 47종으로 조사지점중 이 지역의 식생이 가장 다양하였다. 식물사회학적 방법에 따라 분류된 하천식생의 식물군락은 10개의 수생식물 군락과 2개의 습생 및 수변식물 군락으로 대별되어졌다. 이들 군락들에 대한 4종류(종수, 종의 풍부도지수, 종의 이질성지수, 종의 균등도지수)의 종 다양성과 토양요인(pH, EC, 유기물 함량, 전질소, 인삭)과의 관계를 분석한 결과 pH가 높을수록 4종류의 종 다양성 지수는 높아 졌으며, EC는 값이 높을수록 종수(SN), 종의 풍부도지수(SR), 종의 이질성지수(H'), 종의 균등도지수(J')가 낮아 졌다. 또한 유기물 함량(OM)과 전질소(T-N)의 경우도 4종류의 다양성지수와는 부의 상관관계를 나타내었다. 인산(P₂O_(5))은 4종류의 다양성 지수의 변화에 영향을 미치지 않았다. This study was conducted to evaluate influence of chemical properties in the riparian on the species diversity and to get plant information for enhancement of natural purification in Mankyeong River. The concentration of total nitrogen was high in Jeonju and Sam stream, while that of total nitrogen showed the highest peak in Winter. Concentrations of NH₄-N was 0.01-0.06 ㎎/L in Gosan and Soyang stream. The water quality of upstream along with Mankyeong River was suitable for the imgation source. The riparian vegetation was investigated by Zurich-Montpellier school's method from June, 2001 to September, 2002. The number of riparian plants were 59 families, 129 genera, 165 species, 20 varieties in Gosancheon, on the while 53 families, 111 genera, 141 species, 19 varieties in Soyangcheon The number of riparian plants in Hari basin was higher than that of other sites namely, 73 families, 134 genera, 218 species, 33 varieties. Riparian vegetation was consisted of 12 plant communities. The contents of organic matter, total nitrogen and electrical conductivity had negative relationship with species diversity (Species richness index, Heterogeneity index, Species evenness index, Species number). On the while, species diversity had positive relationship with soil pH. Species diversity of the plant communities were affected by topography and disturbance.

외상후 발작의 위험인자에 대한 조사

이재학,배학근,윤석만,도재원,이경석,윤일규,최순관,변박장 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.1

Risk Factors for Posttraumatic Seizure The authors evaluate the risk factors for posttraumatic seizures. this prospective study was performed in a series of 470 head injured patient from January 1996 to Decomber 1998. The patients who were dead within 1 week of injury or children from 3 years old and under were excluded. There were 358 male and 112 female with a mean age of 35.2±22.8 years (range, 4-88 years). The results were as follows : 1). Of the 470 patients, pasttraumatic seizure occurred in 48 patients(10.2%): early seizure in 28(6%) and late seizure in 20 patients(4.2%). 2). The clinical risk factors for posttraumatic seizure were poor consciousness at admission, presence of brainstem herniation signs, poor GCS score, and posttraumatic amnesia more than 24 hours after trauma(p<0.001). 3). The radiological risk factors for posttraumatic seizure were subdural hematoma(p<0.001), intracerebral hematoma (p<0.02), mutiple intracranial CT lesions(p<0.001), or delayed lesions on follow-up CT scans(p<0.001). the incidence of seizure increased according to the severity of diffuse brain lesion(p<0.001), and the seizure rate in mass lesion was higher than that in diffuse lesion(p<0.001). 5). Hypoxia and coagulopathy had a statistically significant influence on posttraumatic seizure(p<0.05). Hypoxia had a infuence on occurrence of late seizure(p<0.05). 6). The incidence of posttraumatic seizure signiticantly increased in surgical group compared with coservative group(p<0.001) and significantly increased in patient who underwent decompressive craniectomy compared with those who underwent craniotomy(p<0.001) 7). Preventive administration of antiepileptic drugs decreased the incidence of early seizure, but did not affect on the reduction of late seizure. 8). Multivariate logistic regression analysis showed the subdural hematoma, GCS score, delayed lesion, and intracerebral hematoma in order of importance for seizure risk. in conclusion, the risk factors affecting on the occurrence of seizure were clinical status at admission, CT lesions, and severity of diffuse brain inJury. Considering that hypoxia affected on the late seizure, it is necessary to detect and treat it immediately after trauma. In addition, the patients who underwent decompressive craniectomy should be carefully followed to evaluate the risk of late seizure. Even though preventive administration of antiepileptic drugs had a tendency to decrease the incidence of early seizure, it is unclear whether administration of antiepileptic drugs can reduce the incidence of posttraumatic seizures. Prospective study will be needed in the selected patients.

p-Anisaldehyde가 조골세포 분화에 미치는 영향

김경민 ․ 이도원 ․ 김현준 ․ 김아랑 ․ 장원구 대구대학교 산업기술연구소 2018 産業技術硏究 Vol.29 No.2

p-Anisaldehyde is a natural fragrance extracted from Pimpinella anisum L., and used as a preservative. This study examined the effect of p-anisaldehyde on osteoblast differentiation. First, cytotoxicity tests were carried out after examining the concentrations that did not show toxicity to the cells. The expression of osteoblast differentiation marker gene was confirmed by RT-PCR and was not effective in the treatment with p-anisaldehyde alone. However, p-anisaldehyde decreased the expression levels of inhibitor of differentiation-1 (Id1), distalless related homeobox (Dlx5), and runt-related transcription factor 2 (Runx2), which are osteogenic differentiation marker genes, which are increased in osteogenic condition. alkaline phosphatase (ALP) activity was also confirmed by ALP staining that p-anisaldehyde reduced ALP activity. These results show that p-anisaldehyde is effective in reducing osteoblast differentiation.

唐代字樣著作에 나타난 正字觀 및 그 理論根據 : 顔之推 《顔氏家訓·書證篇》의 文字觀

李景遠 中國語文硏究會 1997 中國語文論叢 Vol.12 No.-

자동차 주행용 광섬유 자이로스코프 개발

이승원,박경섭 울산대학교 1997 공학연구논문집 Vol.28 No.1

적당한 성능의 광섬유 자이로스코프는 자동차 주행용의 회전율 측정 센서로 사용할 수 있다. 본 논문에서 구성한 광섬유 자이로스코프 시스템은 개회로 방식의 신호 처리를 하며, 단일 모드 광섬유와 방향성 결합기를 이용하여 시스템을 광섬유 일체식으로 구성하였다. 광원으로는 비편광 광원인 He-Ne 레이저를 사용하였다. 자동차 주행용으로 사용할 수 있도록 간단한 구성과 저가격이 되도록 하였다. 본 논문에서는 modified J₁…J₄ 방법을 응용한 신호 처리 방식을 사용하였다. 간섭계 출력을 고속 푸리에 변환(fast Fourier transform : FFT)하여 4 개의 연속 고조파를 구한 다음, modified J₁…J₄를 적용하여 변조도(modulation index)를 구한다. 이 방법은 광원의 파장변동이나 편광 상태의 변화 등에 상관없이 계측할 수 있다. 여기서 구한 변조도를 이용하여 Bessel 함수 ??를 계산한 결과와, 두 고조파의 비로 간단하게 회전율을 구할 수 있었다. Fiber-optic gyroscope of modest performance can be used as angular rate sensor for vechile navigation on land. A practical design is used an open-loop configuration with an all-fiber optical system together with single-mode fiber and directional coupler. We use the unpolarized light source, He-Ne laser as light source, and design simple construction for low cost. In this paper, we used the modified J₁…J₄ method which apply the signal processing technique. Measurements were made of the amplitudes of four harmonics in the electrical spectrum of the output of an interferometer using fast Fourier transform(FFT), and modified J₁…J₄ was used to determine the amplitude of the modulation index. This method allowed us independents of the wavelength fluctuation of the wavelength fluctuation of source and state of polarization changes in measurement. We can simply get the rotation rate with two harmonics ratio, Bessel function, ?? and the modulation depth.