• 한국정보통신학회논문지
• /
• 제12권10호
• /
• pp.1822-1829
• /
• 2008

항체가 정밀한 항법 정보를 얻기 위해서는 관성 센서의 초기 오차에 대한 보정이 매우 중요하다. 본 논문에서는 레이트 테이블과 고성능 센서를 기준 센서로 사용하여, 저급 MEMS 관성 센서 오차 보정에 따르는 비용과 효율성의 어려움을 극복하는 방법을 제안하였다. 초기 오차 보정 과정에서 기준 센서와 타겟 센서에 같은 동적 입력을 인가한 후 결과를 분석하였다. 실험 결과를 통해 제안된 초기 오차 보정 방법이 실제로 매우 효율적이며 유용함을 확인할 수 있었다.

• Steel and Composite Structures
• /
• 제38권6호
• /
• pp.705-716
• /
• 2021

An innovative partially precast partially encased composite beam (PPECB) is put forward based on the existing research. In order to study the flexural performance of the new composite beam which has precast part and cast-in-place part, six prefabricated specimens and one cast-in-place specimen are designed with considering the influence of the production method, the steel flange thickness, the concrete strength grade and the stirrup process on the behavior of the composite beam. Through four points loading and test data collection and analysis, the behavior of partially prefabricated specimen is similar to that of cast-in-place specimen, and the casting method, the thickness of the steel flange, the concrete strength grade and the stirrup process have different influence on the crack, yield and peak load bearing capacity of the component. Finally, the calculation theory of plastic bending of partially precast partially encased concrete composite beams is given. The calculation results are in good agreement with the experimental results, which can be used for practical engineering theory guidance. This paper can provide reference value for further research and engineering application.

• 자원리싸이클링
• /
• 제30권1호
• /
• pp.26-34
• /
• 2021

타이타늄은 구조용 금속 중 알루미늄, 철, 마그네슘에 이어서 네 번째로 풍부한 금속이지만, 금속으로의 제련이 어려워 희소금속으로 분류되고 있다. 특히 타이타늄의 제련공정은 에너지 다소비형 공정이다. 타이타늄 스크랩으로 잉곳을 제조하면 에너지 소비량과 CO2 발생량을 약 95 %까지 절감할 수 있다. 그러나 스크랩 중의 철분과 산소 등의 불순물을 제거하기 어려워 리사이클링 되는 양은 한정되어 있다. 일반적으로 고품위 타이타늄 스크랩은 순타이타늄 스펀지의 재용해 공정에 투입하여 희석하고, 저품위 스크랩은 페로타이타늄 제조용 원료로 사용되고 있다. 본 논문에서는 이러한 타이타늄의 리사이클링 기술을 이해하기 위해 타아타늄의 제련기술과 리사이클링 기술에 대하여 고찰하였다.

• Geomechanics and Engineering
• /
• 제29권1호
• /
• pp.79-90
• /
• 2022

Soybean-urease induced carbonate precipitation (EICP), as an alternative to microbially induced carbonate precipitation (MICP), was employed for soil improvement. Meanwhile, soluble calcium produced from industrial waste carbide slag powder (CSP) via the acid dissolution method was used for the EICP process. The ratio of CSP to the acetic acid solution was optimized to obtain a desirable calcium concentration with an appropriate pH. The calcium solution was then used for the sand columns test, and the engineering properties of the EICP-treated sand, including unconfined compressive strength, permeability, and calcium carbonate content, were evaluated. Results showed that the properties of the biocemented sand using the CSP derived calcium solution were comparable to those using the reagent grade CaCl₂. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses revealed that spherical vaterite crystals were mainly formed when the CSP-derived calcium solution was used. In contrast, spherical calcite crystals were primarily formed as the reagent grade CaCl₂ was used. This study highlighted that it was effective and sustainable to use soluble calcium produced from CSP for the EICP process.

• Educational Technology International
• /
• 제9권1호
• /
• pp.79-96
• /
• 2008

The issue of connection between entities has a lengthy history in educational research, especially since it provides the necessary bridge between base and target in analogical transfer. Recently, the connection has been viewed through the application of technology to bridge between sequences in order to be cognitively useful. This study reports the effect of sequence type (AT vs. TA) and connection type (fading vs. popping) on the achievement and analogical transfer in a multimedia application. In the current research, 10th -grade and 11th -grade biology students in Korea were randomly assigned to five groups to test the effects of presentation sequence and entity connection type on analogical transfer. Consistent with previous studies, sequence type has a significant effect: analogical transfer performance was better when base representations were presented first followed by target representations rather than the reverse order. This is probably because presenting a familiar base first helps in understanding a less familiar target. However, no fully significant differences were found with the entity connection types (fading vs. popping) in analogical transfer. According to the Markman and Gentner's (2005) spatial model, analogy in a space is influenced only by the differences between concepts, not by distance in space. Thus connection types fail on the basis of this spatial model in analogical transfer test. The findings and their implications for sequence and connection research and practice are discussed. Leveraging on the analogical learning process, specific implications for scaffolding learning processes and the development of adaptive expertise are drawn.

• 한국수소및신에너지학회논문집
• /
• 제35권1호
• /
• pp.90-96
• /
• 2024

In this paper, a new technology to obtain electronic grade, highly pure carbon dioxide by using membrane and liquefied natural gas (LNG) cold heat assisted cryogenic distillation has been proposed. PRO/II with PROVISION release 2023.1 from AVEVA company was used, and Peng-Robinson equation of the state model with Twu's alpha function to predict pure component vapor pressure versus temperature more accurately was selected for the modeling of the membrane and cryogenic distillation process. Advantage of using membrane separation instead of selecting absorber-stripper configuration for the concentration of carbon dioxide was the reduction of carbon dioxide capture cost.

• 문화기술의 융합
• /
• 제10권1호
• /
• pp.129-136
• /
• 2024

본 연구의 목적은 유아기 어머니 양육효능감이 초등학교 1학년 학교적응에 미치는 영향에서 유아기 외현화문제행동과 학교준비도의 매개효과를 고찰하는 것이다. 한국아동패널 자료를 사용했으며 Process macro를 활용하여 유아기 매개효과를 검증했다. 연구결과를 요약하면 첫째, 유아기 어머니 양육효능감이 초등학교 1학년 학교적응에 영향을 미치는 관계에서 유아기의 외현화문제행동과 학교준비도는 각각 부분 매개효과를 갖는 것으로 나타났다. 둘째, 유아기 어머니 양육효능감이 초등학교 1학년 학교적응에 영향을 미치는 관계에서 외현화문제행동과 학교준비도는 순차적 이중매개효과를 가지는 것으로 밝혀졌다.

• 임상간호연구
• /
• 제22권2호
• /
• pp.238-247
• /
• 2016

Purpose: This study was done to develop an evidence-based practice guideline for catheter dysfunction in hemodialysis patients. Methods: Development of the guideline process was done according to the De Novo development version 1.0 by NECA which consists of 12 steps. Results: The developed guideline consisted of 5 domains and 14 recommendations. The number of recommendations for each domain were: 3 on catheter dysfunction assessment, 1 on conservative management of catheter dysfunction, 7 on drug management of catheter dysfunction, 1 on catheter function test and 2 on maintenance management. Of the recommendations, 7.15% were marked as A grade, 52.85% of B grade, and 50% of C grade. Conclusion: Findings in this study indicate that this guideline can be added to the evidence-based practice guidelines for fundamentals of practice and that this guideline can be disseminated to nurses nationwide in order to improve the care of hemodialysis patients with catheter dysfunction.

• 한국초등과학교육학회지:초등과학교육
• /
• 제37권1호
• /
• pp.12-26
• /
• 2018

The purpose of this study was to investigate the characteristics of reasoning in which $3^{rd}$ grade elementary school students form ideas, design experiments, and interpret the results to solve problems in small group argumentation. For this purpose, 12 3rd-grade students' small group argumentations including experiments were observed. The researchers analyzed students' pre- and post-open questionnaires, field notes, and video recordings of small group argumentation. The results of the research are as follows. First, in the initial opinion formation process, a hasty unification of opinions and a transformation of inquiry problem occurred. In the design and execution of experiments, verification experiments and unplanned and arbitrary experiments were performed. They also selectively noticed or accepted claims, evidence, interpretation, and criticism. They could distinguish between the condition and the cause, but they were confused by using inaccurate terms and tended to keep the initial opinions when interpreting the results and drawing conclusions.

• 한국수학교육학회지시리즈A:수학교육
• /
• 제47권4호
• /
• pp.487-503
• /
• 2008

In this paper, descriptive assessment method for middle school mathematics was evaluated by developing a framework for designing and grading problems for descriptive assessment and analyzing the effectiveness of the problems. The new descriptive assessment problems were developed by reviewing the current 7th National Mathematics Curriculum of Korea and aligned mathematics textbooks to define a set of problem design principles and evaluation framework for the assessment strategy. The developed problems were first pilot tested and then revised based on the feedback from the test. The final version was field tested by 100 students in 7th grade middle school. After the field test, the problems were graded by two middle school math teachers and one math education researcher to determine the overall correlation between graders and also to analyze effectiveness of the evaluation framework of the test. This result of this study is expected to assist in the further development of descriptive problems and grading framework by providing a reference work for teachers to better understand the process and the limitations of executing the new assessment strategy.