• 대한토목학회논문집
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• 제38권6호
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• pp.809-818
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• 2018

논문에서는 북한지역에서의 미래 기후변화에 따른 재해영향 정도를 평가하기 위해 WMO에서 제공하고 있는 북한지역의 각 관측소별 기후자료를 수집하여 북한의 시계열자료를 수집하였고, RCP기후변화시나리오를 이용하여 북한에서의 기후변화의 변동성 및 이로 인한 재해가 발생되었을 때 지역의 재해 취약성을 이용하여 기후변화가 재해에 미치는 영향을 평가하였다. 이를 평가하기 위해 북한의 11개 행정구역을 대상으로 각 단계별로 설계강우부하, 인간위험지수(Human Risk Index; HRI), 재해영향지수(Disaster Impact Index; DII)에 대해 평가를 수행하였다. 그 결과 Future 1기간일 때 자강도가 보통(C등급)에서 위험(B등급)으로 상승했다. Future 2일때 황해북도는 그대로 위험하다고 나타났고 강원도와 황해북도의 등급이 보통(C등급)으로 상승했다. Future 3의 경우 평양시가 보통(C등급)에서 안전(D등급)으로 하강하였으며, 함경남도와 개성시가 위험(B등급)에서 보통(C등급)으로 하강, 강원도, 자강도가 보통(C등급)에서 안전(D등급)으로 하강, 평양시가 보통(C등급)에서 안전(D등급)으로 하강하리라 전망되었다.

• 펄프종이기술
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• 제35권4호
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• pp.48-56
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• 2003

In this work an integrated model for paper plants combining wet-end and dry section is developed and a model predictive control scheme based on the plant model is proposed. Closed-loop process identification method is employed to produce a state-space model. Thick stock, filler flow, machine speed and steam pressure are selected as input variables and basis weight, ash content and moisture content are considered as output variables. The desired output trajectory is constructed in the form of 1st-order dynamics. Results of simulations for control of grade change operations are compared with plant operation data collected during the grade change operations under the same conditions as in simulations. From the comparison, we can see that the proposed model predictive control scheme reduces the grade change time and achieves stable steady-state.

• 펄프종이기술
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• 제36권5호
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• pp.11-20
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• 2004

In this work the Model Algorithmic Control (MAC) method is applied to control the grade change operations in paper mills. The neural network model for the grade change operations is identified first and the impulse model is extracted from the neural network model. Results of simulations for MAC control of grade change operations are compared with plant operation data. The major contribution of the present work is the application of MAC in the industrial plants based on the identification of neural network models. We can confirm that the proposed MAC method exhibits faster responses and less oscillatory behavior compared to the plant operation data in the grade change operations.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2004년도 추계학술발표집
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• pp.212-220
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• 2004

In this work the Dynamic Matrix Control method is applied to control the grade change operations in paper mills. Paper process trained by neural network regards a real-plant. The model obtained with operation data is used to achieve DMC. Results of simulations for DMC control of grade change operations are compared with plant operation data response. From the comparison, we can see that the proposed DMC method exhibits faster response for the grade change of paper and achieves stable steady-state.

• 한국안광학회지
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• 제7권2호
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• pp.217-221
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• 2002

전북 익산시에 소재한 초등학교 전체 아동을 대상으로 3년 동안 나안시력과 교정시력을 측정하여 다음과 같은 결과를 얻었다. 1. 나안시력 0.6 이하는 학년이 높아질수록 증가하였고 이를 교정시킨 비율도 증가하였다. 2. 현재 사용하고 있는 안경 중에 재 교정이 필요한 아동은 전체 안경 착용자의 30%이었다. 3. 저학년 때보다 학년이 높을수록 시력이 좋거나 나쁜 쪽으로 분포하였다. 4. 1학년이 3학년이 되었을 때 나안시력변화는 0.2에서는 증가하였고 0.7과 1.0에서는 감소하였으나 4학년이 6학년이 되었을 때에는 변동이 작았다.

• 한국터널지하공간학회 논문집
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• 제21권6호
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• pp.825-835
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• 2019

터널 설계 시 조사를 통하여 지반을 여러 개의 등급으로 분류한 후 지보패턴표에 따라 해당 지보시스템을 적용하게 된다. 그러나 암반 등급을 기준으로 한 단순한 패턴 적용방식은 암반 등급 경계부에서 발생하는 종방향 응력 전이를 고려하지 못한다. 본 연구는 NATM 터널의 종방향 암반 등급 변화부에서 응력 변화를 추정하기 위한 3차원 수치해석을 실시하였으며 Influence Line (영향선) 및 Trend Line (경향선)을 이용하여 하중전이 영향권을 파악하고자 하였다. 연구 결과 터널 굴착방향으로 암반 등급이 하향 변화하면 등급변화 경계를 중심으로 강성이 약한 암반에서 강성이 큰 암반 방향으로 0.35~0.7D 범위에서 응력 전이가 발생하며 이를 고려하여 암반 등급의 종방향 하향 변화부에서는 연구결과의 0.35~0.7D 영향권을 감안하여 안전측으로 1.0D 정도의 하향패턴을 추가 적용하는 것이 필요하다.

• 한국환경교육학회지:환경교육
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• 제22권1호
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• pp.68-82
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• 2009

Global climate change is associated with all of the human activity, and its sudden change can be taken an issue of the serious environmental problem in our human society. The purpose of this study is to develope the goal and the content system for the climate change education. As a result, first, according to the questionnaires on climate change, students from Grade 3 to Grade 10 seem to interpret it as fragmentary perspectives. In addition, in terms of students' own actions as the corresponding strategy to climate change, the higher their grades were, the lower their actions were. Second, the development goal on climate change and its educational directions were set by reflecting students' perception. The education goal on climate change is to perceive the changing environment by understanding phenomena of climate change, to propose plans that can mitigate and adjust climate change through a variety of research, and to keep practicing the proposed plans as a member of a community for the global environment. Third, fields and items of educational contents to climate change were created and drawn out. The content system is composed of 'basic science of climate change', 'relationship with climate change', and 'coping with climate change'. Furthermore, concrete contents for the climate change education in elementary school were suggested so that its goal and content system can be used in the existing curriculum.

• Journal of Korean Neurosurgical Society
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• 제46권1호
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• pp.16-22
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• 2009

Objective : This study was designed to investigate automated pressure-controlled discography (APCD) findings, to calculate the elastance of intervertebral discs, and to assess the relationship between the calculated elastance and disc degeneration. Methods : APCD was performed in 19 patients. There were a total of 49 intervertebral discs treated. Following intradiscal puncture, a dye was constantly injected and the intradiscal pressure was continuously measured. The elastance of the intervertebral disc was defined as unit change in intradiscal pressure per fractional change in injected dye volume. Disc degeneration was graded using a modified Dallas discogram scale. Results : The mean elastance was 43.0${\pm}$9.6 psi/mL in Grade 0, 39.5${\pm}$8.3 psi/mL in Grade 1, 30.5${\pm}$22.3 psi/mL in Grade 2, 30.5${\pm}$22.3 psi/mL in Grade 3, 13.2${\pm}$8.3 psi/mL in Grade 4 and 6.9${\pm}$3.8 psi/mL in Grade 5. The elastance showed significant negative correlation with the degree of degeneration ($R^2$=0.529, P=0.000). Conclusion: APCD liberates the examiner from the data acquisition process during discography. This will likely improve the quality of data and the reliability of discography. Elastance could be used as an indicator of disc degeneration.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 추계 학술논문 발표대회
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• pp.207-208
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• 2012

This study is aimed to utilize for basic material of concrete quality management through evaluate properties of fresh and hardened concrete with the aggregate quality. As a result, fine aggregate's slump change of between one grade was 8~82% and in case of coarse aggregate, slump change of between one grade was 2~22% on same mixing condition. The unit water for same workability condition, unit water was increased 16kg/㎥ with decreasing of one grade for fine aggregate and unit water was increased 5kg/㎥ with decreasing of one grade for coarse aggregate.

• 한국과학교육학회지
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• 제15권4호
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• pp.429-436
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• 1995

The purpose of this study is to identify students' alternative frameworks about tide concept, to investigate some characters of them and students' understanding types with increasing grade in secondary school earth science course. The objective questionnaire method was used, and the subjects of this study are 528 students selected randomly in secondary school. The results are as follow. 1) Thirteen alternative frameworks about tide concept, related to the phase change of the moon and the motion of the earth are identified. 2) The alternative frameworks needed mechanical and causal reasoning have the trend reinforced or sophisticated with increasing the grade. And alternative frameworks needed phenomenal and mechanical, phenomenal and causal reasoning are changed little but ones needed phenomenal, variative and basic reasoning change scientifically. The rates of the alternative frameworks needed definitional, empirical, phenomenal reasoning decrease at the learning grade of that concept but increase after that grade. 3) Middle school students have the definitional, phenomenal, empirical and qualitative understanding types but high school students have the causal, analytic, quantitative and mechanical ones on tide concept.