말기신부전 환자에서 발견된 국소적 총장골동맥류

최혁준 ( Hyuk Joon Choi ),김준철 ( Jun Chul Kim ),김종열 ( Jong Yeol Kim ),김동훈 ( Dong Hoon Kim ),서안나 ( An Na Seo ),김덕실 ( Duck Sil Kim ),김성완 ( Sung Wan Kim ) 대한내과학회 2011 대한내과학회지 Vol.80 No.5

An isolated aneurysm of the iliac artery is a very rare disease that can occur as the result of atherosclerotic degeneration, mycosis, trauma, medial necrosis, fibrodysplasia, or Marfan syndrome. This abnormality is often asymptomatic, and it has a potential risk of rupture. Since patients with chronic renal failure on hemodialysis have many comorbid conditions, the risk of rupture is increased. Here, we report the case of an isolated common iliac artery aneurysm that was caused by atherosclerosis in a patient on hemodialysis, and we review the relevant literature.

포도종자유 급여가 본태성고혈압쥐의 혈청지질 성분에 미치는 영향

최혁준(Choi Hyuk-Joon ),황윤희(Whang Yoon-Hee ),백운화(Pek Un-Hua),신효선(Shin Hyo-Sun) 韓國營養學會 1990 Journal of Nutrition and Health Vol.23 No.7

복합개념상황에서 고등학생들의 문제해결력과 정신용량

최혁준 ( Hyuk Joon Choi ),박호진 ( Ho Jeen Park ),권재술 ( Jae Sool Kwon ) 한국과학교육학회 2004 한국과학교육학회지 Vol.24 No.5

In this study, we examined high school students` abilities for solving problems under single concept situations and complex concept situations and their mental capacities. Single concept situations are defined as the problems which can be solved with a scientific concept or principle and complex concept situations are the problems combined with more than 2 single concept situations. 152 11th-graders were participated in this study, who had taken natural science track. FIT 752 was used to measure their mental capacities. And an instrument, made up of six questions under three single concept situations and three complex concept situations, was used to assess students` problem solving abilities. As results, students` problem solving abilities were lower in complex concept situations than in single concept situations. There wasn`t significant difference in mental capacities between of students who succeeded in solving problems and ones who did not under both single and complex concept situations. Although students solved the problems of single concept situations, some of them failed in solving the problems of complex concept situations composed of single concept situations which they succeeded in solving. They belonged to relatively low mental capacity group, of which students who failed in solving problems of complex situations had lower metal capacities than ones who succeeded in solving them. According to these results, it could be concluded that mental capacity is one of main variables which have influence on problem solving of complex concept situations composed of solvable single concept situations.

컴퓨터 기반 과학 수행평가 문항 개발: 전류계와 전압계 회로 연결 실험

최혁준 ( Hyuk Joon Choi ) 경북대학교 과학교육연구소 2013 科學敎育硏究誌 Vol.37 No.2

과학교육에서 컴퓨터는 교수·학습 뿐 아니라 평가의 목적으로도 활용되고 있다. 죽, 컴퓨터의 장점을 살린 컴퓨터 기반 평가가 실시되고 있다. 그러나 이와 같은 평가는 주로 과정 중심이 아닌 결과 중심의 평가이며, 피험자의 수만큼 컴퓨터가 있어야 하므로 학교의 정규 시험으로 활용하기 곤란하다. 그러나 수행평가의 경우 일반적으로 평가 과제가 미리 공개되므로 학급별 또는 학생별로 평가 시간이 다르게 평가를 실시하는 것이 가능하다. 따라서 본 연구에서는 실제 실험기구를 사용한 실험평가를 대체할 수 있는 컴퓨터 기반 수행평가 문항을 개발하였다. 이를 위해 먼저 물리 교사를 대상으로 과학교육에 있어 이러한 기능에 대한 평가의 필요성 및 어려운 점 등에 대한 설문조사를 실시하였고, 이를 반영하여 전류계와 전압계를 포함한 회로를 구성을 하는 평가 문항을 개발하였다. 개발된컴퓨터 기반 문항은 실제의 실험기구를 사용하여 진행되는 평가와 유사하게 구성하였으며 평가 과정에서 학생들의 수행에 따라 적절한 피드백을 제공하고, 수행 결과를 자동적으로 채점할 수 있도록하였다. 이를 위해 컴퓨터가 학생들의 수행 결과의 정확성을 판단할 수 있는 알고리즘을 개발하였다. The purpose of this study is to develop the science item on computer-based performance assessment which is able to replace the assessment with actual experimental apparatus. The survey on the necessities and the difficulties of the assessment with actual experimental apparatus was conducted with 57 physics teachers. By reflecting the results of the survey, the computer-based assessment items which are related with constructing circuits with an ammeter and a voltmeter were developed. The developed computer-based assessment items were organized in similarity to assessment conducted with actual experimental apparatus, proper feedback was provided by students` performance in the process of assessment so as to grading performance results automatically. To achieve them, the algorithm was developed so that computer can judge the accuracy of students` performance results.

우리나라 PISA 2012 과학 영역 결과 분석: PISA 2009 및 PISA 2006의 평가틀 하위요소별 정답률과의 비교

최혁준 ( Hyuk Joon Choi ) 한국교원대학교 과학교육연구소 2014 청람과학교육연구논총 Vol.20 No.2

The purpose of this study was to analyze the results of science performance in PISA 2012 focusing on the results of Korea and to compare the percentages of correct answers of science framework``s sub-categories such as context, competency and knowledge in PISA 2012 with those in PISA 2009 and PISA 2006 in order to suggest ideas about teaching-learning and assessment in Korean science education. Korea``s mean score of science literacy in PISA 2012 was 538 points, which is similar to the mean score in PISA 2009 and higher than in PISA 2006. Comparing with the results in PISA 2006, most of the average percentages of correct answers by the sub-categories/item types in the PISA 2012 were increased. On the other hand, some average percentages of correct answers by the sub-categories/item types in PISA 2012 were lower than in PISA 2009. Especially the average percentages of ``identifying scientific issues``, ``scientific enquiry``, and ``open constructed-response`` in PISA 2012 were lower than in PISA 2009 by more than 1 percentage point.

복막투석의 합병증으로 발생한 복막-후복막 누출

최혁준 ( Hyuk Joon Choi ),김종열 ( Jong Yeol Kim ),최지영 ( Ji Young Choi ),조지형 ( Ji Hyung Cho ),김찬덕 ( Chan Duck Kim ),박선희 ( Sun Hee Park ),김용림 ( Yong Lim Kim ) 대한내과학회 2011 대한내과학회지 Vol.80 No.1

We report a case of retroperitoneal and scrotal dialysate leakage resulting from peritoneal-retroperitoneal communication in a patient on peritoneal dialysis (PD). The ultrafiltration volume was reduced and the scrotum became enlarged in a patient who had been undergoing PD for 4 years. Retroperitoneal and scrotal leakage of dialysate was confirmed by computed tomography (CT) performed 1 hour after the intraperitoneal infusion of contrast-containing dialysate. The PD was halted and the patient was transferred to hemodialysis (HD). One month after the transfer to HD, the PD was resumed and there were no signs of extraperitoneal leakage. (Korean J Med 2011;80:108-112)

위성정보에 의한 강우예측과 홍수유출 및 범람 연계 해석 (Ⅰ) : 이론 및 모형의 개발

최혁준(Choi Hyuk Joon),한건연(Han Kun Yeun),김광섭(Kim Gwangseob) 대한토목학회 2006 대한토목학회논문집 B Vol.26 No.6B

본 연구의 목적은 인공위성 자료와 지상의 관측자료간의 비선형 특성을 가장 잘 반영할 수 있는 신경망 모형을 이용하여 단시간 강우량 정보를 사전에 예측하여, 하천제방의 붕괴로 인한 상습 침수지역에서의 홍수범람 양상을 실시간으로 예측함으로써 홍수재해로부터의 피해를 최소화시키는데 있다. 강우예측 신경망 모형은 현재의 대기상태를 나타내는 인공위성 자료와 실시간으로 전송되는 자동기상관측소 자료를 입력자료로 하여 현재부터 3시간 및 6시간 선행시간까지의 면적평균강우량을 예측할 수 있도록 구성하였다. 신경망 모형의 구조는 입력층과 출력층 사이에 하나의 은닌층이 존재하는 다층 신경망으로 구성하였으며, 학습단계에서는 오류 역전파 알고리듬 학습방법 중 모멘텀법을 사용하였다. 예측된 면적평균강우량으로부터 홍수량을 산정하고, 이를 이용하여 하천의 제방붕괴로 인한 제내지에서의 범람양상을 예측할 수 있도록 1차원 흐름모형과 연계한 동역학적 홍수범람 모형을 개발하였다. 개발된 홍수범람 모형은 본류와 지류의 여러 지점에서 제방이 붕괴될 경우, 하도의 홍수위 및 제내지에서의 침수위와 침수면적이 일괄적으로 모의될 수 있도록 구성하였다. The purpose of this study is to improve the short term rainfall forecast skill using neural network model that can deal with the non-linear behavior between satellite data and ground observation, and minimize the flood damage. To overcome the geographical limitation of Korean peninsula and get the long forecast lead time of 3 to 6 hour, the developed rainfall forecast model took satellite imageries and wide range AWS data. The architecture of neural network model is a multi-layer neural network which consists of one input layer, one hidden layer, and one output layer. Neural network is trained using a momentum back propagation algorithm. Flood was estimated using rainfall forecasts. We developed a dynamic flood inundation model which is associated with l-dimensional flood routing model. Therefore the model can forecast flood aspect in a protected lowland by levee failure of river. In the case of multiple levee breaks at main stream and tributaries, the developed flood inundation model can estimate flood level in a river and inundation level and area in a protected lowland simultaneously.

무중력 상태에 대한 예상의 확인 결과가 예비 초등 교사의 인지갈등과 개념변화에 미치는 영향

최혁준 ( Hyuk Joon Choi ),김준태 ( Jun Tae Kim ),권재술 ( Jae Sool Kwon ) 한국초등과학교육학회 2005 초등과학교육 Vol.24 No.1

This study examined the effects of the result of ascertaining predictions on cognitive conflict and conceptual change when students learned the concept of weightlessness. Participants were 200 pre-service elementary teachers. They answered the pretest composed of two items. Through the demonstration on either of two items of the pretest, they identified whether their predictions were correct or not. In addition, students` cognitive conflicts were measured. After brief instructional treatment, the posttest was conducted. The results of this study are as follows: The more students who identified their own predictions on the experiment were incorrect there were, the more effective it was on cognitive conflict and conceptual change. And cognitive conflicts and conceptual changes of students who identified that their predictions were incorrect were generated meaningfully more than those of students who identified that their predictions were correct. From these results, it is concluded that students who identified that their predictions were correct experience cognitive conflicts, but their cognitive conflicts and conceptual changes were smaller than those of students who identified that their predictions were incorrect.

과학 개념 학습에서 배경 지식이 문제를 해결하는데 미치는 영향

최혁준 ( Hyuk Joon Choi ) 한국초등과학교육학회 2009 초등과학교육 Vol.28 No.1

위성정보에 의한 강우예측과 홍수유출 및 범람 연계 해석 (Ⅱ) : 적용 및 분석

최혁준(Choi Hyuk Joon),한건연(Han Kun Yeun),김광섭(Kim Gwangseob) 대한토목학회 2006 대한토목학회논문집 B Vol.26 No.6B

본 연구(Ⅱ)에서는 2002년 8월 집중호우시 낙동강 유역에 대하여 강우예측 신경망 모형을 적용하였다. 예측된 3시간 선행 강우량은 실제 관측된 강우량의 패턴을 잘 따르고 있었으며, 기존의 연구와 비교하여 선행시간을 감안하면 강우예측의 정확성이 향상되었음을 확인할 수 있었다. 또한 동일한 유역의 실제 제방붕괴에 따른 범랑양상을 모의하였다. 이때 예측된 강우량 자료는 유역에서의 홍수량 산정을 위한 기본자료로 이용되었으며, 유역에서의 홍수량은 하도 및 제내지에서의 홍수범람 모의를 위한 경계조건으로 이용되었다. 모의결과는 실제 범람흔적과 하천에서의 홍수위 자료와 비교하여 잘 일치되고 있음을 확인할 수 있었다. 본 연구를 통해서 집중호우나 태풍과 같은 이상강우의 강우예측에 대한 인공위성 자료의 실질적인 활용성을 제공하였으며, 위성자료를 이용한 강우예측 기법과 연계하여 국내 실정에 맞는 홍수유출 및 홍수범람 모형의 개발을 통합함으로써 홍수재해에서의 강우, 유출, 범람에 대한 체계적인 실무적용에 사용될 수 있을 것으로 판단되었다. In this study(Ⅱ), The developed rainfall forecast model was applied to the NakDong River Basin for the heavy rainfall on 6th to 16th of August in 2002. The results demonstrated that the rainfall forecasts of 3 hours lead time showed good agreement with observed data. The inundation aspect of simulation depends on actual levee failure in the same basin. Rainfall forecasts were used for flood amount computation in the target watershed. Also the flood amount in the target watershed was used on boundary condition for flood inundation simulation in a protected lowland and a river. The results of simulation are consistent with actuality inundation traces and flood level data of the target watershed. This study provides practical applicability of satellite data in rainfall forecast of extreme events such as heavy rainfall or typhoon. Also this study presented an advanced integrated model of rainfall, runoff, and inundation analysis which can be applicable for flood disaster prevention and mitigation.