화학문제의 요구주의력과 학습자의 기능적 정신용량과의 관계

崔秉舜,金都旭 한국교원대학교 과학교육연구소 1998 청람과학교육연구논총 Vol.8 No.1

이 연구에서는 100명의 인문계 고등학생을 대상으로 화학양론과 관련된 문제의 해결에서, 과제의 요구주의력 결정 방법과 학습자의 덩이지식화 정도가 화학문제의 요구주의력과 학습자의 기능적 정신용량과의 관계에 미치는 영향을 분석하였다. 연구결과에 의하면, 과제에 포함된 조작스키머 종류의 수를 그 과제의 요구주의력으로 보는 것이 가장 타당함을 알 수 있었다. 또한, 학습자의 덩이지식화 정도가 과제의 요구주의력과 학습자의 기능적 정신용량과의 관계에 영향을 미치는 중요한 변인이며, Pascual-Leone의 이론으로부터 가정할 수 있는 임계상황이 나타나지 않는 중요한 이유임을 알 수 있었다. The puprpose of this study was to investigate the influence of the way determining mental demand of the problem and the extent of chunking of the learner on the relations between the mental demand of the problem and mental capacity of the students in solving chemical stoichiometry problems of 11th grade students. It was found that the number of types of operative scheme included in the problem was considered the mental demand of the problem. It was also found that the extent of chunking of the learner was one of the important factors influencing on the relations between the mental demand of the problem and mental capacity of the students in solving chemical stoichiometry problems.

보조기를 이용한 족관절 외과 골절의 비수술적 치료

최남홍,곽호윤,송백용,배상욱,이인묵,김도현 대한골절학회 2003 대한골절학회지 Vol.16 No.3

목적: 이번 연구의 목적은 보조기를 이용하여 최소 전위된 족관절 외과 골절의 보존적 치료 결과를 알아보는 것이다. 대상 및 방법: 11명 (11예)의 환자들이 수상 후 8주간 전 체중 부하 보행으로 보존적 치료를 받았다. 적응증으로는 3㎜ 이하의 골절 전위, 내과 부분의 동통과 부종이 없거나 있어도 미약한 경우, 거골의 외측 전위가 없는 경우로 삼았다. 환자들은 AOFAS (the American Orthopedic Foor and Ankle Society) Ankle-Hindfoot Scale에 의해 평가받았다. 결과: 평균 103주 (36~192주)의 추시 관찰을 하였으며, 전례에서 발목 관절의 운동 범위는 정상이었다. 평균 AOFAS Ankle-Hindfoot Scale 점수는 95점이었다. 결론: 보조기를 이용한 보존적 치료의 장점은 조기에 전 체중 부하 보행을 하며 일상생활 및 사회생활을 영위할 수 있다는 것, 환자의 편안함, 그리고 재활 치료 기간의 단축이었다. 그러므로 최소 전위된 족관절 외과 골절에 보조기를 이용한 보존적 치료는 권할만하다. Purpose: The purpose of this study was to evaluate the outcome of conservative treatment for minimal displaced lateral mallolar fracture using ankle brace. Materials and Methods: Eleven patients (eleven ankles) underwent conservative treatment with ankle brace for 8 weeks with full weight bearing ambulation. Inclusion criteria were minimal displacement (<3㎜) of fracture, no or mild tenderness or swelling on medial malleolar area and no lateral shift of talus. The patients were evaluated with AOFAS (the American Orthopedic Foot and Ankle society) Ankle-Hindfoot scale. Result: Average follow up was 103 weeks (36~192). All cases had normal range of motion of ankle. The average score of AOFAS Ankle-Hindfoot scale was 95 points. Conclusion: The advantages of conservative treatment with ankle brace were early return to daily activity and work, comfort to the patients and a short period of rehabilitation. Conservative treatment with ankle brace for minimal displaced lateral malleolar fracture is recommended.

흉추 경막외강으로 침윤한 흉선종 1례 : Metstasis to Thoracic Epidural Space

최정훈,백욱성,박대곤,오경구,최천식,배상도 高麗病院 1987 高醫 Vol.10 No.-

유압식 인버터 제어기의 속도제어를 위한 퍼지기반 하이브리드 슬라이딩모드 제어기 설계

한권상,최병욱,안현식,김도현 제어·자동화·시스템공학회 2003 제어·자동화·시스템공학논문지 Vol.9 No.3

19세기 西進東漸의 파도 속에서 국가의 자립과 근대화를 위해 몸소 힘썼던 兪吉潛과 福澤??論의 사상 가운데 그들의 政淪論을 한국과 일본의 근대화 방향 차이를 중심으로 살펴보고자 한다. Due to the friction characteristics of pump, cylinder packing and passenger car, in the elevation system actuated with hydraulic inverter, there exist dead zones, which cannot be controlled by a PID controller. To overcome the drawbacks, in this paper, we propose a new hybrid fuzzy-sliding mode control scheme, which controls the controller output between a sliding mode control output and a PID control output by fuzzy control method. The proposed hybrid control scheme achieves an improved control performance by using both controllers: We first propose a design method of the hybrid controller for a hydraulic system controlled by inverters, then propose a design method of a hybrid fuzzy-sliding mode control scheme. The effectiveness of the proposed control scheme is shown by simulation results, in which the proposed hybrid control method yields better control performance then the PID controlled scheme, not only in the zero-crossing speed region but also in the overall control region including steady-state region.

CaSO_4 :Mn 열발광선량계의 물리적 특성

강영호,라병욱,최태진,김도성,도시홍 慶北大學校 物理化學硏究所 1986 硏究論文集 Vol.7 No.-

열발광형광체는 방사선계측 및 선량측정에 널리 사용되고 있다. CaSO_4에 Mn을 활성화하여 CaSO_4 : Mn TL 시료를 직접제작하여 이의 열발광특성을 조사하였다. 측정된 CaSO_4 : Mn의 glow-curve 5℃/sec의 가온율에서 peak온도가 126℃였으며, Halperin과 Braner 및 Chen의 이론에 의하여 열발광과정의 차수와 활성화에너지를 결정하였다. 제작된 CaSO_4 : Mn의 TL 강도는 10^-2 ∼ 10^4 Rad의 ^60Co γ선에 대해 선형적인 선량의존성을 보였으며, 100시간에 50% 정도의 fading을 나타내었다. The thermoluminescent phosphors have been widely used in radiation detection and dosimetry. By adding Mn activator to CaSO_4, the CaSO_4 : Mn thermoluminescent phosphor was prepared and its characteristics was investigated. The measured glow-curve of CaSO_4 : Mn phosphor consisted of a single peak around 126℃ at the heating rate of 5℃/sec. The kinetics order of thermoluminescence process and the activation energy of electron trap was determined by analyzing the glow-curves based upon Halperin and Braner, and Chen's theories. The prepared CaSO_4 : Mn phosphor showed the linear dose response within the range of 10^-2 to 10^4 rad of gamma-ray and fading of 50% in 100 hours after irradiation at room temperature.

Anti-inflammatory effect of lovastatin is mediated via the modulation of NF-κB and inhibition of HDAC1 and the PI3K/Akt/mTOR pathway in RAW264.7 macrophages

Choi, Hyung-Wook,Shin, Pyung-Gyun,Lee, Ji-Hyun,Choi, Woo-Suk,Kang, Min-Jae,Kong, Won-Sik,Oh, Min-Ji,Seo, Yong-Bae,Kim, Gun-Do D.A. Spandidos 2018 INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE Vol.41 No.2

<P> Lovastatin is a 3-hydroxy-3-methylglutaryl-CoA reductase inhibitor that is clinically used for the prevention of cardiovascular diseases. Although it has been reported that lovastatin has anti-inflammatory properties in several studies, how lovastatin regulates the inflammation is still unclear. To evaluate the effect of lovastatin on nitric oxide production (NO) in RAW264.7 macrophages, NO production assay was performed. Also, cell viability was measured to confirm cytotoxicity. Level of tumor necrosis factor-α (TNF-α) transcription was measured by reverse transcription polymerase chain reaction (RT-PCR) from total RNA in RAW264.7 cells. Western blot analysis and immunofluorescence staining were used to investigate the regulation of lovastatin on the expression, phosphorylation, and nuclear translocation of cellular proteins. The results of the present study revealed that lovastatin reduced nitric oxide production via the reduction of inducible nitric oxide synthase (iNOS) expression in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. The mRNA level of TNF-α was reduced in presence of lovastatin. In addition, lovastatin downregulated histone deacetylase 1 (HDAC1), resulting in the accumulation of acetylated histone H3 and heat shock protein 70. Furthermore, the expression of phosphoinositide 3-kinase catalytic subunits α and β was reduced under lovastatin treatment, and the phosphorylation of Akt and mammalian target of rapamycin was consequently inhibited. Lovastatin also inhibited the phosphorylation of inhibitor of nuclear factor (NF)-κBα and the translocation of NF-κB into the nucleus. Therefore, the present study demonstrates that lovastatin inhibits the expression of pro-inflammatory mediators, including iNOS and TNF-α, through the suppression of HDAC1 expression, PI3K/Akt phosphorylation and NF-κB translocation in LPS-stimulated RAW264.7 macrophage cells. </P>

Exposure to environmental chemicals among Korean adults-updates from the second Korean National Environmental Health Survey (2012–2014)

Choi, Wookhee,Kim, Suejin,Baek, Yong-Wook,Choi, Kyungho,Lee, Keejae,Kim, Sungkyoon,Yu, Seung Do,Choi, Kyunghee Elsevier 2017 International journal of hygiene and environmental Vol.220 No.2

<P><B>Abstract</B></P> <P>National biomonitoring program can offer solid scientific evidence on exposure profiles of environmental chemicals at a national level, and provide a snapshot of changing exposure level over time. Therefore, several countries have maintained such programs for developing environmental health policies. The Korean National Environmental Health Survey (KoNEHS) was designed to understand the level of human exposure to environmental chemicals by time and location, and to identify possible sources of such exposure. The 2nd stage of KoNEHS, which was conducted between 2012 and 2014, examined a total of 6478 adult subjects over 19 years of age, and measured 21 environmental chemicals of major policy concern. Compared to the findings from the first stage monitoring (2009–2011), slightly higher levels of blood lead were observed, while those of mercury remained similar. Blood metal concentrations, however, were higher than those reported from national biomonitoring programs of United States, Germany and Canada. The urinary concentrations of phthalates metabolites were lower, but those of t,t-muconic acid and BPA were higher than those reported in the first stage survey. The urinary cotinine level decreased perhaps reflecting general declining patterns of first- and second-hand smoking. The results of the second stage survey were made available for public use since April 2016.</P> <P>Some policy efforts appear to be at least in part effective on mitigating chemical exposure among people, e.g., urinary phthalate metabolites and cotinine, while further confirmations are warranted. In-depth assessments will be conducted to identify vulnerable groups and important exposure pathways.</P>

층류 순산소 연소에서 CO₂몰분율에 따른 매연 배출 특성에 관한 연구

최도욱(Do Wook Choi),김규보(Gyu Bo Kim),전충환(Chung Hwan Jeon),장영준(Youg June Chang),송주헌(Ju Hun Song) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11

Oxy-fuel combustion is a reliable way for the reduction of pollutants, the higher combustion efficiency and the separation of carbon dioxide. In this study, An experimental study was performed to investigate the influence of soot emission in laboratory-scale oxy-fuel burner. The experimental conditions are fixed up fuel(CH₄) and oxidizer(O₂) rate. But inert gas(CO₂) rate was changed. Also the study was performed in the laminar diffusion flame. As an optical method, laser induced incandescence is useful to get the information for spatial and temporal soot emission. Therefore, Soot emission measurements were performed to the technique of laser induced incandescence(LII) and 2D image was detected by ICCD camera. As a result of this experimental study, confirmed to Characteristic of soot emission in Oxy-fuel combustion.

자율주행을 위한 차량제어시스템의 구성

강도욱(Do-Wook Kang),성경복(Kyung-Bok Sung),민경욱(Kyung-Wook Min),최정단(Jeong Dan Choi) 대한전자공학회 2020 대한전자공학회 학술대회 Vol.2020 No.8

머신러닝을 이용한 스타트 모터의 고장예지

고도현(Do-Hyun Ko),최욱현(Wook-Hyun Choi),최성대(Seong-Dae Choi),허장욱(Jang-Wook Hur) 한국기계가공학회 2021 한국기계가공학회지 Vol.20 No.12

In our daily life, artificial intelligence performs simple and complicated tasks like us, including operating mobile phones and working at homes and workplaces. Artificial intelligence is used in industrial technology for diagnosing various types of equipment using the machine learning technology. This study presents a fault mode effect analysis (FMEA) of start motors using machine learning and big data. Through multiple data collection, we observed that the primary failure of the start motor was caused by the melting of the magnetic switch inside the start motor causing it to fail. Long-short-term memory (LSTM) was used to diagnose the condition of the magnetic locations, and synthetic data were generated using the synthetic minority oversampling technique (SMOTE). This technique has the advantage of increasing the data accuracy. LSTM can also predict a start motor failure.