방사선사진의 인덱스-순서 분석을 통한 치아경조직의 탈염화 검출

박동현,박영호,김경숙,박정훈,이기자,최삼진,최용석,황의환,박헌국 대한구강악안면방사선학회 2009 Imaging Science in Dentistry Vol.39 No.2

Purpose : The purpose of this study was to develop the radiographic technique for detecting the demineralization which is known as indication of dental caries. Materials and Methods : This technique was based on the comparing of multiple radiographs which was irradiated by multiple X-ray spectra. For the meaningful comparing, the multiple radiographs were reconstructed to the dosimetrically consistent images using a standard material. The difference of resulting images of same target with multiple spectra represents the difference of response of material as regards the spectra. Results : We have found about 10% of demineralization of dental hard tissues particularly in the proximal region through the analyzing of differences. Conclusion : Most intriguing thing in this investigation was that the method to analyze difference shows us to an anatomic structure of dental hard tissues even if absolute values of optical density were excluded during the procedures.

개에서 이중 결찰법을 통한 동맥관 개존증의 완치 예

윤헌영,정순욱,박희명,박철,정만복,김준영,한현정,황민,노병국,박상혁,장하영,박정윤 한국임상수의학회 2004 한국임상수의학회지 Vol.21 No.1

A ten months old, female Yorkshire terrier weighing 2.88 kg referred to veterinary teaching hospital of college of veterinary medicine, Konkuk University because of syncope, cough and dyspnea. First hematological and serum chemical test revealed thrombocytopenia, mild anemia, and increase of concentration of ALP (195 U/L). On 57 days later, second hematological and serum chemical test revealed polycythemia, increase of concentration of ALP (211 U/L), and Tchol (387 mg/dl). Right atrium enlargement, main pulmonary artery bulge and cardiomegaly (VHS = 11.5) were observed in radiographic findings. Ultrasonographic images showed both right and left ventricular dilation and turbulent flow between the descending aorta and the main pulmonary artery in color Doppler imaging. ECG showed left ventricular enlargement, SA block, and electrical alternant. Thoracotomy was performed through left fourth intercostal incision under isoflurane anesthesia. Patent ductus arteriosus was double ligated with 1-0 silk. Cough and dyspnea disappeared on 5 days after operation. Turbulent flow was not found in color doppler imaging of ultrasonography on 10 days after operation. Ten months later after the operation, syncope could not exist any more.

중학교 화학 분야의 개념 연구에 대한 문제점 분석

朴恩姬,姜대勳,白盛惠,朴國泰,金惠敬,蔡禹기,權鈞 한국교원대학교 과학교육연구소 1999 청람과학교육연구논총 Vol.9 No.1

중학교 화학 분야의 오개념 조사에 사용된 설문지의 문제점을 밝혀, 학생들의 정확한 오개념 조사를 위한 바탕을 마련하고자 한다. 기존의 중학교 화학 분야에 대한 오개념 조사 설문지가 연구 대상 학생들에게 잘못 사용되고 있었으며, 문항 내용 자체에도 오류가 있었음을 지적하고자 하는 것이다. 선행 연구들의 분석 결과들이 오개념이 아니라 무개념임을 확인하기 위하여 중학교 1학년 학생 182명을 대상으로 두 종류의 설문지 A와 B를 투입하여 조사하였다. 설문지 A는 오개념 연구를 위해 선행 연구들에서 사용한 문항들로 이루어진 것으로, 이를 투입한 결과를 선행 연구들의 결과들과 비교하기 위한 것이다. 그리고 설문지 B는 설문지 A에서 응답한 학생들의 구체적인 생각을 알아보기 위하여 새롭게 개발한 것이다. 설문지 A를 통해 얻은 결과와 선행 연구들에서 얻은 결과들을 비교할 때, 전반적으로 일관성이 없게 나타났으며, 중학교 1학년 학생들의 주관식 정답률이 객관식 정답률에 비해 매우 낮게 나타나는 공통점은 있었으나, 문항 자체의 오류들이 발견되었다. 설문지 B를 통해 학생들의 생각을 알아본 결과, 설문지 A에서 과학적 개념과 오개념으로 분류된 학생들 중에서 무개념으로 판단된 경우가 많았다. This study was to clarify the problems of questionnaires related to misconception researches of middle school chemistry and to prepare a ground for the correct misconception research for students. For these purposes, the questionnaires of the misconception researches related to chemistry in middle school were analyzed, and the mistakes of the questions which were used in 7th grade students were found, based on a definition of misconceptions in this study. Also, the errors in contents of the questionnaires were indicated. The results of the analysis revealed that most of the 7th grade students did not have misconceptions contrary to some of the previous researches conclusions. They only had no conceptions related to the contents. In order to support this analysis, two different questionnaire sets (questionnaire set A and B) for 182 7th grade students were used. After obtaining similar results to those of the previous researches by the questionnaire set A, the students' thoughts were examined by the questionnaire set B. From the results of this study, the correct answer rates of subjective questions were very low compared with those of objective questions in the questionnaire set A for 7th grade students. It was hard to find consistency among the results of the researches using the questionnaire set A. And many contents of the questions consisted of the questionnaire set A were not consisted with a definition of misconceptions. There were errors in the contents of the questions, too. The students classified as the having-science-concepts group and the having-misconceptions group by the questionnaire set A were classified as the having-no-concepts group by the questionnaire set B.

인공 치아우식 발생 모델에서 디지털 방사선 공제술을 이용한 인접면 치아우식증의 진단

박정훈,최용석,황의환,이기자,최삼진,박영호,김경숙,진현석,홍경원,오범석,박헌국 대한구강악안면방사선학회 2009 Imaging Science in Dentistry Vol.39 No.1

Purpose : The purpose of the experiment was to evaluating the diagnostic ability of dental caries detection using digital subtraction in the artificial caries activity model. Materials and Methods : Digital radiographies of five teeth with 8 proximal surfaces were obtained by CCD sensor (Kodak RVG 6100 using a size #2). The digital radiographic images and subtraction images from artificial proximal caries were examined and interpreted. In this study, we proposed novel caries detection method which could diagnose the dental proximal caries from single digital radiographic image. Results : In artificial caries activity model, the range of lesional depth was 572-1,374 μm and the range of lesional area was 36.95-138.52mm². The lesional depth and the area were significantly increased with demineralization time (p<0.001). Furthermore, the proximal caries detection using digital subtraction radiography showed high detection rate compared to the proximal caries examination using simple digital radiograph. Conclusion : The results demonstrated that the digital subtraction radiography from single radiographic image of artificial caries was highly efficient in the detection of dental caries compared to the data from simple digital radiograph.

중등학교에서의 용해 현상의 지도 실태 조사

姜?勳,白盛惠,朴國泰 한국교원대학교 과학교육연구소 2000 청람과학교육연구논총 Vol.10 No.1

이 연구에서는 중등학교 과학 교과서에서의 용해 현상 및 그와 관련된 내용에 대한 설명의 적절성과 과학 교사들의 지도 실태를 알아보았다. 연구 결과, 현재의 중 · 고등학교 과학 교과서에는 용해를 단순히 두 물질이 고르게 섞이거나 한 물질이 다른 물질 속으로 녹아 들어가는 현상으로 설명을 하고 있어 용해 과정을 용매화로 제대로 이해하기 어려운 실정이다. 또한, 설문 응답 교사들 중에는 용해를 콩 사이로 좁쌀이 끼어 들어가는 것과 같이 입자의 크기 차이에 비유하여 설명하는 경우가 많았다. 이와 같은 결과는 교사 자신이 용해 현상에 대해서 잘못 이해하고 있을 뿐 아니라 학생들에게 잘못된 개념이 그대로 전수되는 것으로 보인다. 결국 교사가 가지고 있는 옳지 못한 개념이 학생들에게 그대로 전이되어 용해에 대한 올바른 개념 형성을 어렵게 만들 것으로 생각된다. This study was to examine the appropriateness of explanation and science teachers' teaching practices on dissolution in secondary school science textbooks. The result showed that students had difficulty in understanding the process of dissolution as solvation. Because the textbooks referred dissolution as a mixture of two substances. According to the survey, many teachers usually compared dissolution to small particles' filling the space between large particles due to the difference of size among particles such as beans and rices. This survey told us that teachers themselves misunderstood dissolution. Eventually, students are expected to have a hard time in forming the right concept of dissolution by the misunderstanding of teachers.

중학생들의 용해 현상 이해에 대한 연구

강대훈,白盛惠,朴國泰 한국교원대학교 과학교육연구소 2001 청람과학교육연구논총 Vol.11 No.1

이 연구에서는 중학생들의 용해 현상 및 그와 관련된 내용에 대한 이해 실태를 알아보았다. 연구 결과 75% 이상의 학생들이 용해를 입자의 크기 차이로 인하여 한 물질이 다른 물질 사이로 들어가는 현상으로 이해하고 있었으며, 일부 학생들은 용해가 일어나면 용질이 없어지거나 용매에 포함되는 것으로 이해하고 있었다. 또한, 학생들은 용해 현상을 큰 입자 사이로 작은 입자가 들어가는 것으로 이해함으로써 정작 용해가 될 때 부피가 감소하는 이유를 제대로 설명하지 못하였다. 그리고 용해도에 미치는 용질 상호간의 영향에 대한 이해는 매우 낮은 것으로 나타났다. 이와 같은 결과는 중학교 과학 교과서의 용해 관련 개념의 설명이 불충분하고 과학 교사들의 부적절한 모형 사용에 의한 설명 때문으로 생각된다. 따라서, 중학생의 이해 수준에 알맞은 교과서의 설명과 용해 현상을 입자적 관점에서 시각적으로 보여줄 수 있는 적절한 모형의 개발이 요구된다. This study was to examine middle school students' understanding of dissolution. More than 75% students understood that dissolution was caused by small particles' filling the space between large particles due to the difference of size among particles. Some other students responded that solute disappeared or was absorbed in a solvent as the result of dissolution. Besides, they didn't know that space between particles was the reason of the volume's decreasing after the process of dissolution. Instead, they explained that space between particles caused dissolution. And they hardly understood the fact that solutes affect solubility. Students' misunderstanding about the concept of dissolution resulted from the lack of the explanation on the right concept of dissolution in science textbooks and the inappropriate use of the dissolution model by teachers. In conclusion, we need the appropriate explanation in middle school science textbooks that consider the students' level and the development of the appropriate model that demonstrates dissolution in the perspective of particles.

브라켓과 탄선 간의 마찰 전후 표면 변화 분석 : 원자현미경을 이용한 예비연구

이태희,박기호,전지윤,김수정,박헌국,박영국 대한치과교정학회 2010 대한치과교정학회지 Vol.40 No.3

브라켓과 호선 간에 발생하는 마찰은 치아 이동의 효율에 상당한 영향을 미친다. 마찰력에 기여하는 요소 중 특히 브라켓과 호선의 표면조도는 중요한 요소이다. 본 연구는 브라켓과 탄선을 실험적으로 마찰시킨 후, 원자현미경 (atomic force microscope, AFM)을 사용하여 브라켓 슬롯과 교정용 탄선의 표면 조도 변화를 정성적, 정량적으로 측정하고 비교 평가하여 브라켓과 호선 간의 마찰이 각각의 표면 변화에 미치는 영향을 규명하고자 시행되었다. 스테인리스 스틸 브라켓과 세라믹 브라켓에 각각 스테인리스 스틸 탄선과 TMA 탄선을 실험적으로 활주마찰시킨 후 각각을 원자현미경을 이용하여 표면을 관찰하였다. 실험결과 브라켓보다는 교정용 탄선에서 활주마찰 후에 더 많은 표면 변화가 나타났다. 또한 활주마찰 후에 스테인리스 스틸 브라켓은 표면 조도의 유의한 변화가 없었으나 세라믹 브라켓은 표면 조도가 감소하였다. 그리고 교정용 탄선은 모두 활주마찰 후에 표면 조도가 증가하였으며 이러한 표면 변화는 스테인리스 스틸 브라켓보다 세라믹 브라켓과의 활주마찰 후에 더 큰 것으로 관찰되었다. 본 실험으로 원자현미경은 브라켓 슬롯과 탄선의 표면 조도를 정량적으로 측정하는 데에 유용한 수단임을 알 수 있었다. Objective: The surface roughness of orthodontic materials is an essential factor that determines the coefficient of friction and the effectiveness of tooth movement. The aim of this study is to evaluate the surface roughness change of the brackets and wires after experimental sliding quantitatively. Methods: Before and after experimental sliding tests, the surface roughness of stainless steel brackets, ceramic brackets, stainless steel wires, and beta-titanium (TMA) wires were investigated and compared using atomic force microscopy (AFM). Results: After sliding tests, changes in the surface of the wire were greater than changes in the bracket slot surface. The surface roughness of the stainless steel bracket was not significantly increased after sliding test, whereas the roughness of ceramic brackets was decreased. Both the surface roughness of stainless steel and TMA wires were increased after sliding test. More changes were observed on the ceramic bracket than the stainless steel bracket. Conclusions: AFM is a valuable research tool when analyzing the surface roughness of the brackets and wires quantitatively.

초등학교와 중학교 과학 교과서의 화학 영역에 대한 연계성과 중학생들의 화학 개념에 대한 인식 분석

韓有花,강대훈,梁一鎬,白盛惠,朴國泰 한국교원대학교 과학교육연구소 1999 청람과학교육연구논총 Vol.9 No.1

제 6차 교육과정에 따른 초등학교와 중학교 과학 교과서의 화학 영역에 대한 연계성을 분석하고, 화학 개념에 대한 중학생들의 인식을 조사하여, 학습자 수준에 맞고 연계성 있는 과학 교과서 제작의 기초를 제공하고자 한다. 이를 위하여 초등학교와 중학교 과학과목의 교육목표와 화학 영역 내용체계간의 연계성을 분석하고, 화학 개념에 대한 중학생들의 인식을 조사하였다. 연구 결과, 제 6차 교육과정의 초등학교와 중학교 과학과 교육목표는 거의 반복 진술되어 있음을 알 수 있었다. 또한, 물질의 미시적 세계를 다루고 있는 물질의 구성 영역에서 초등학교와 중학교간의 단원별 목표와 내용체계의 간격이 다소 큰 것으로 보아 연계성이 부족하다는 것도 알 수 있었다. 그리고 연계성이 부족한 영역에 대해 학생들은 대체적으로 이해하기 어렵다는 반응을 보였으며, 연계성 있는 내용조직이 학생들의 내용 이해에 영향을 줄 수 있다는 것을 알 수 있었다. This study was to analyze the articulation between chemistry contents of science textbooks at elementary and middle school level, to survey students' perceptions on chemistry concepts, to establish guidelines for science textbooks that not only meet the needs of learners but also fit in a coherent way. In order to do this, we analyzed links of the aims and the organization of chemistry contents of elementary and middle school science textbooks, we also surveyed students' perceptions on chemistry concepts students had retained. The study revealed that the 6th middle school curriculum was almost a duplicate of the elementary school syllabus. And there was no interrelation between the organization of chemistry contents and the aim of the chapter which built up a logical picture of the world at a molecular level. It was also found that the lack of coherence between science textbooks in elementary and middle school was a major cause of student difficulty.

Effectiveness and Safety of Biolimus A9™-Eluting stEnt in Patients with AcUTe Coronary sYndrome; A Multicenter, Observational Study (BEAUTY Study)

Park, Keun-Ho,Jeong, Myung Ho,Hong, Young Joon,Ahn, Youngkeun,Kim, Hyun Kuk,Koh, Young Yub,Kim, Doo Il,Kim, Sang Wook,Kim, Weon,Rha, Seung Woon,Rhew, Jay Young,Park, Jong Seon,Park, Hun Sik,Bae, Jang Yonsei University, College of Medicine 2018 Yonsei medical journal Vol.59 No.1

<P><B>Purpose</B></P><P>This study sought to determine the 1-year clinical effectiveness and safety of a biodegradable, polymer-containing Biolimus A9™-eluting stent (BES) in Korean patients with acute coronary syndrome (ACS).</P><P><B>Materials and Methods</B></P><P>A total of 1000 ACS patients with 1251 lesions who underwent implantation of BESs at 22 centers in Korea were enrolled between May 2011 and July 2013. We assessed major adverse cardiac events (MACE) defined as the composite of cardiac death, non-fatal myocardial infarction (MI), and clinical-driven target vessel revascularization at 12 months.</P><P><B>Results</B></P><P>Patient mean age was 62.6±11.4 years. 72.8% of the patients were male, 28.5% had diabetes, 32.8% had multi-vessel disease (MVD), and 47.9% presented with acute MI (AMI). The mean global registry of acute coronary events risk score of all patients was 103.0±27.6. The number of stents per patient was 1.3±0.6. The incidences of MACE and definite stent thrombosis at 12 months were 3.9% and 0.2%, respectively. On multivariate Cox-regression analysis, age ≥65 years was identified as an independent predictors of 1-year MACE (hazard ratio=2.474; 95% confidence interval=1.202−5.091). Subgroup analyses revealed no significant differences in the incidence of MACE between patients with and without diabetes (4.3% vs. 3.7%, <I>p</I>=0.667), between those who presented with and without AMI (4.4% vs. 3.4%, <I>p</I>=0.403), and between those with and without MVD (4.6% vs. 3.5%, <I>p</I>=0.387).</P><P><B>Conclusion</B></P><P>Our study demonstrated excellent 1-year clinical outcomes of BES implantation in patients at low-risk for ACS.</P>

HIT PV Module Performance Research for an Improvement of Long-term Reliability: A Review

Park, Hyeong Sik,Jeong, Jae-Seong,Park, Chang Kyun,Lim, Kyung Jin,Shin, Won Seok,Kim, Yong Jun,Kang, Jun Young,Kim, Young Kuk,Park, No Chang,Nam, Sang-Hun,Boo, Jin-Hyo,Yi, Junsin Korea Photovoltaic Society 2017 Current Photovoltaic Research Vol.5 No.2

We report finding ways to improve the long-term reliability of PV module including the heterostructure with the intrinsic thin layer (HIT) solar cell. We point out the stability of the products of Panasonic HIT cell. We account for a brief description of the module manufacturing process to investigate the issues of each process and analyze the causes. We carried out the silicon PV module of the glass to glass type under the damp heat test around 1000 hours. However, it degraded around 7% of PV module power after 300 hours exposure in comparison with the initial status (Initial: 12.7 Watt). We investigated possible cause and solutions for the module performance to develop the long-term reliability.