• 한국과학교육학회지
• /
• 제43권1호
• /
• pp.17-28
• /
• 2023

디지털 기반 지능 정보 사회로의 진입에 발맞추어 과학 교육과정에서는 과학과의 교과역량 함양을 강조하고 있으며, 역량 평가의 측면에서 컴퓨터 기반 평가가 관심을 받고 있다. 컴퓨터 기반 평가는 높은 실제성을 갖는 형태로 문항을 구현할 수 있고, 평가 결과를 데이터베이스로 축적하여 환류 체계를 구축함에 있어서도 이점이 있다. 다만, 평가 타당도 개선, 측정 효율성 저하, 관리 요소 증가 등의 문제를 해결할 필요가 있다. 본 연구에서는 학업성취도 평가가 지필평가에서 컴퓨터 기반 평가로 전환되는 과정에서 새로운 평가의 도입에 따른 학생들의 반응을 살펴보기 위해 2021년도에 시행된 학업성취도 평가의 지필평가와 컴퓨터 기반 평가의 병행시행 결과를 분석하였다. 특히, 동일한 문항을 평가 매체만을 변화시켰을 때 학생들의 성취에 미치는 영향, 컴퓨터 기반 평가의 장점을 살린 새로운 기능을 포함하여 문항을 구성했을 때의 변화가 학생들의 성취에 미치는 영향을 살펴보았다. 중학교 3학년 학생 7,137명이 지필평가와 2종의 컴퓨터 기반 평가 중 하나에 응시한 결과를 분석하였다. 평가 시행 후 집단별로 문항의 정답률과 변별도 평균을 산출하였으며, 학업성취도 출제 경험이 있는 과학교사 8명이 참여한 전문가 협의회를 통해 응답 특성에 대한 전문가 의견을 수렴하였다. 결과에 따르면 지필평가와 단순 모드 전환형 평가에서의 학생들의 성취 결과는 큰 차이는 없어 매체 효과가 거의 나타나지 않았다. 다만, 서답형 문항의 정답률이 컴퓨터 기반 평가에서 다소 높게 나타났음을 확인하였고, 이는 응답의 편이성과 관련되는 것으로 분석하였다. 한편, 컴퓨터 기반 평가 도입에 따라 새로운 기능들이 적용된 문항들에서 유사한 문항의 정답률과 차이가 10%p 이상인 문항들이 존재하였다. 학생들의 답지 반응을 분석한 바에 따르면, 이는 새로운 기능을 통해 마련한 혁신적인 문항들이 학생들의 이해 수준을 보다 세밀하게 파악한 결과로 볼 수 있었다. 결과를 토대로 컴퓨터 기반 평가를 도입하고 개발할 때 유의할 사항을 논의하고 시사점을 제시하였다.

• Neonatal Medicine
• /
• 제25권1호
• /
• pp.7-15
• /
• 2018

We need to understand the outcomes into adulthood for survivors born either extremely low birthweight (ELBW; <1,000 g) or extremely preterm (EP; <28 weeks' gestational age), particularly their blood pressure and cardiovascular metabolic status,respiratory function, growth, psychological and mental health performance, and functional outcomes. Blood pressure is higher in late adolescence and early adulthood in ELBW/EP survivors compared with controls. In some studies, expreterm survivors have higher insulin and blood lipid concentrations than controls, which may also increase their risk for later cardiovascular disease. ELBW/EP survivors have more expiratory airflow obstruction than do controls. Those who had bronchopulmonary dysplasia (BPD) in the newborn period have even worse lung function than those who did not have BPD. As a group, they are unlikely to achieve their full lung growth potential, which means that more of them are likely to develop chronic obstructive airway disease in later life. Although they are smaller than term born controls, their weight gradually rises and ultimately reaches a mean z-score close to zero in late adolescence, and they ultimately attain a height z-score close to their mid-parental height z-score. On average, ex-preterm survivors have intelligence quotient (IQ) scores and performance on tests of academic achievement approximately 2/3 SD lower than do controls, and they also perform less well on tests of attention and executive function. They have similar high rates of anxiety and depression symptoms in late adolescence as do controls. They are, however, over-represented in population registries for rarer disorders such as schizophrenia and Autism Spectrum Disorder. In cohort studies, ex-preterm survivors mostly report good quality of life and participation in daily activities, and they report good levels of self-esteem. In population studies, they require higher levels of economic assistance, such as disability pensions, they do not achieve education levels as high as controls, fewer are married, and their rates of reproduction are lower, at least in early adulthood. Survivors born ELBW/EP will present more and more to health carers in adulthood, as they survive in larger numbers.

• 한국과학교육학회지
• /
• 제20권3호
• /
• pp.468-478
• /
• 2000

본 연구에서는 상호작용을 강화한 형성평가 수업전략이 학생들의 과학 개념 이해 및 과학 관련 태도에 미치는 효과와 이 수업전략에 대한 학생들의 인식을 조사하고자 하였다. 이를 위하여 서울 소재 남녀공학 중학교의 2학년 4개 반을 실험집단으로 다른 4개 반을 비교집단으로 선정하여 실험집단에는 상호작용을 강화한 형성평가 수업전략을, 비교집단에는 교사 강의식 전통적 수업전략을 적용하였다. 그 결과 본 연구에서 적용한 형성평가 수업전략은 전통적 수업전략에 비해 학생들의 과학 개념 이해에는 효과적이나 과학 관련 태도에는 차이가 없는 것으로 나타났다. 그리고 실험집단에서 수업 전후에 과학 개념 이해의 향상 정도는 집단 내의 과학성적 수준이나 인지 수준별로 유의미한 차이를 보이지 않았다. 본 연구의 수업전략에 대한 학생들의 인식은 질문과 응답에 의한 상호작용이 많고, 이를 통해 사고를 촉진할 수 있고 반복학습의 효과가 있으며, 학습 내용을 이해하는데 도움이 되는 것으로 드러났다.

• Journal of Korean Neurosurgical Society
• /
• 제42권3호
• /
• pp.195-199
• /
• 2007

Objective : Bilateral laminotomy and unilateral laminotomy for bilateral decompression are becoming the minimally invasive procedures for lumbar spinal stenosis (LSS). With the aim of less invasiveness and better preservation of spinal stability. these techniques have been developed. But there are no large randomized studies to show the surgical results between these two techniques. The objective of this study was to examine the safety and efficacy of these two minimally invasive techniques. Methods : A total of 80 patients were included in this study (Group I : bilateral laminotomy, Group II : Unilateral laminotomy for bilateral decompression). Perioperative parameters and complications were analyzed. Symptoms and scores such as visual analog scale (VAS) scores, Oswestry Disability Index (ODI) scores, and SF-36 scores of prospectively accrued patients were assessed preoperatively and at 1 month and 12 months after surgery. Paired-t test, two-sample student-t tests, and non parametric tests were used to determine cross-sectional differences between two groups. Results : No major complications such as spinal instability or deaths occurred during follow-up periods. VAS, ODI scores and SF-36 body pain and physical function scores showed statistically significant improvements in both groups (p<0.001). The significant widening of the spinal canal diameter was also noted in both groups. But, in Group II. there were minor postoperative complications such as dural tear (2 cases 5.0%), fracture of ipsilateral inferior facet (1 case 2.5%), and 5 cases of transient leg symptoms of contralateral side. Conclusion : Both bilateral laminotomy and unilateral laminotomy for bilateral decompression allow achievement of adequate and long-lasting operative results in patients with LSS. But postoperative complications are more frequent in Group II (unilateral laminotomy and bilateral decompression). These results indicate that bilateral laminotomy is the preferred minimally invasive technique to treat symptomatic LSS.

• 한국과학교육학회지
• /
• 제14권2호
• /
• pp.214-224
• /
• 1994

The Ministry of Education established the plan to adopt a new college enterance examination system, so called Scholastic Ability Test for college, from 1994. The National Board of Educational Evaluation had carried out 7 experimental trials for the new examination system. Eventhough, the governmental officials advertised the purpose and characteristics of the new examination system, many students and parents did not understand the essential point very well. In this study the researcher tried to analyze the 7 trial examination items and the first Scholastic Ability Test for college carried out 1993. In this study, the researcher tried to find out all the items appeared in the 7 trials. In the analysis, all the individual items from the 1st trial to the 7th trial were used. The research results showed that the items were evenly distributed in all the four areas(Physics, Chemistry, Biology and Earth Science) of science content; however, they were heavily concentrated on data or information analysis categoris in the inquiry domain. In the domain of context, laboratory context was the major item context. The scores were also analyzed. The results showed that no significant difference between male and female students. However, science track students showed higher achievement scores than the non-science track student. The examination result showed high correlation with the tests routinely have carried out in schools. The over all analysis showed the new examination system showed very different characteristics to the conventional tests. Therefore, for the student to get successful result in the Scholastic Ability Test, they should change the way of study. They should try to understand scientific concepts rather than to memorize them. They should invest their time to carry out real experiments rather than to focus on the princples and laws of science. One of the most important thing would be for the student to apply what they learned to real life situations.

• 한국멀티미디어학회논문지
• /
• 제11권8호
• /
• pp.1129-1137
• /
• 2008

전자교육(E-learning)은 새로운 교육의 한 방향으로 사이버학교 뿐만 아니라 기업체의 사원교육, 소비자 교육 등 전반적인 교육현장에서 적용되고 있다. 전자교육에서는 학습도를 평가하는 시험을 온라인으로 실시하며 학습자는 개별적으로 서로 다른 장소에서 응시한다. 온라인 시험은 학습자가 자신의 아이디(ID)와 비밀번호를 타인에게 공개할 수 있어 시험부정이 일어날 가능성이 매우 높다. 그러므로 온라인 시험에서 학습자의 인증은 매우 중요하다. 본 연구는 아이디와 비밀번호를 이용하여 사용자 행동양식에 따른 키보드 적응적 인증 방법을 제안한다. 이 방법은 추가 시스템이 필요하지 않을 뿐만 아니라 사용자의 불편함을 초래하지 않는다. 아이디와 비밀번호를 입력할 때 마다 적응적으로 패턴을 갱신하는 방법을 제안하고 구현과 실험을 통해 기존의 방법보다 우수함을 입증한다.

• 한국과학교육학회지
• /
• 제18권4호
• /
• pp.617-626
• /
• 1998

본 연구의 목적은 국가적 수준에서 우리나라 초 중 고등학교 학생의 과학탐구 능력을 점검해볼 수 있는 평가체제를 개발하는 것이다. 이를 위하여 많은 전문인력이 연구에 참여하였고, 과학탐구 평가틀과 평가 문항을 개발하였다. 개발된 평가 문항을 여러 차례 수정보완한 후, 325개의 문항을 958명의 학생에게 예비 검사를 실시하여 현장 적용 가능성을 검토하였다. 예비 검사 결과 문항 특성이 만족스럽지 못한 문항은 삭제하여 240개의 문항을 본 검사 문항으로 확정하였다. 본 검사는 총 8,906명의 학생을 대상으로 실시하였으며, 검사결과를 고전검사이론과 문항반응이론에 의하여 분석한 결과 난이도, 변별도, 신뢰도 등이 매우 우수하다는 것이 판명되었다. 앞으로 본 연구에서 개발된 과학탐구 평가틀을 이용하여 더 많은 문항이 개발될 수 있으며, 이러한 문항을 이용하여 우리나라 학생들의 과학탐구능력을 주기적으로 점검할 수 있을 것이다.

• Advances in aircraft and spacecraft science
• /
• 제4권2호
• /
• pp.145-167
• /
• 2017

The presented paper gives an overview of several projects addressing the experimental characterization and control of the buffet phenomenon on 3D turbulent wings in transonic flow conditions. This aerodynamic instability induces strong wall pressure fluctuations and therefore limits flight domain. Consequently, to enlarge the latter but also to provide more flexibility during the design phase, it is interesting to try to delay the buffet onset. This paper summarizes the main investigations leading to the achievement of open and closed-loop buffet control and its experimental demonstration. Several wind tunnel tests campaigns, performed on a 3D half wing/fuselage body, enabled to characterize the buffet aerodynamic instability and to study the efficiency of innovative fluidic control devices designed and manufactured by ONERA. The analysis of the open-loop databases demonstrated the effects on the usual buffet characteristics, especially on the shock location and the separation areas on the wing suction side. Using these results, a closed-loop control methodology based on a quasi-steady approach was defined and several architectures were tested for various parameters such as the input signal, the objective function, the tuning of the feedback gain. All closed-loop methods were implemented on a dSPACE device able to estimate in real time the fluidic actuators command calculated mainly from the unsteady pressure sensors data. The efficiency of delaying the buffet onset or limiting its effects was demonstrated using the quasi-steady closed-loop approach and tested in both research and industrial wind tunnel environments.

• Geomechanics and Engineering
• /
• 제19권1호
• /
• pp.37-47
• /
• 2019

The main objective of this study is to evaluate and compare the efficiency of ordinary Portland cement (OPC) in enhancing the unconfined compressive strength of soft soil alone and soft soil mixed with recycled tiles. The recycled tiles have been used to treat soft soil in a previous research by Al-Bared et al. (2019) and the results showed significant improvement, but the improved strength value was for samples treated with low cement content (2%). Hence, OPC is added alone in this research in various proportions and together with the optimum value of recycled tiles in order to investigate the improvement in the strength. The results of the compaction tests of the soft soil treated with recycled tiles and 2, 4, and 6% OPC revealed an increment in the maximum dry density and a decrement in the optimum moisture content. The optimum value of OPC was found to be 6%, at which the strength was the highest for both samples treated with OPC alone and samples treated with OPC and 20% recycled tiles. Under similar curing time, the strength of samples treated with recycled tiles and OPC was higher than the treated soil with the same percentage of OPC alone. The stress-strain curves showed ductile plastic behaviour for the untreated soft clay and brittle behaviour for almost all treated samples with OPC alone and OPC with recycled tiles. The microstructural tests indicated the formation of new cementitious products that were responsible for the improvement of the strength, such as calcium aluminium silicate hydrate. This research promotes recycled tiles as a green stabiliser for soil stabilisation capable of reducing the amount of OPC required for ground improvement. The replacement of OPC with recycled tiles resulted in higher strength compared to the control mix and this achievement may results in reducing both OPC in soil stabilisation and the disposal of recycled tiles into landfills.

• Journal of Power Electronics
• /
• 제19권3호
• /
• pp.784-793
• /
• 2019

Two objectives can be pursued simultaneously with the ${\delta}$ control of a single-phase electric spring (ES). These objectives are the stabilization of the voltage across the critical load (CL) of a power system, and the achievement of a specific functionality similar to the pure compensation of reactive power or the correction of the power factor. However, existing control systems implementing the ${\delta}$ control do not cope with non-ideal operating conditions, such as line voltage distortions, and exhibit a somewhat sluggish regulation of the CL voltage. In an effort to improve both the steady-state and transient performances of an ES power system, this paper proposes implementing the ${\delta}$ control by means of a control system built up on the repetitive control and assisted by state feedback with pole assignment. This paper starts by analyzing the dynamics of an ES power system in terms of its poles and zeros. After that, a reduced second-order model of the dynamics is formulated to avoid a notch filter in the pole assignment. A repetitive control for an ES power system is then designed to meet the two above mentioned objectives. Experimental tests carried out on a laboratory setup demonstrate the effectiveness of the proposed control system in significantly improving the ES power system performance, while reaching the two objectives. In particular, the tests outline the large mitigation of harmonics in the CL voltage under line voltage distortions and its fast stabilization action.