• Title/Summary/Keyword: Grade Change

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Impact Assessment of Climate Change on Disaster Risk in North Korea based on RCP8.5 Climate Change Scenario (RCP8.5 기후변화시나리오를 이용한 기후변화가 북한의 재해위험에 미치는 영향 평가)

  • Jeung, Se-Jin;Kim, Byung-Sik;Chae, Soo Kwon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.38 no.6
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    • pp.809-818
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    • 2018
  • In this paper, in order to evaluate the impact of future climate change in North Korea, we collected the climate data of each station in North Korea provided by WMO and expanded the lack of time series data. Using the RCP climate change scenario, And the impact of climate change on disasters using local vulnerability to disasters in the event of a disaster. In order to evaluate this, the 11 cities in North Korea were evaluated for Design Rainfall Load, human risk index (HRI), and disaster impact index (DII) at each stage. As a result, Jaffe increased from C grade to B grade in the Future 1 period. At Future 2, North Hwanghae proved to be dangerous as it was, and Gangwon-do and Hwanghae-do provincial grade rose to C grade. In the case of Future 3, Pyongyang City dropped from C grade to D grade, Hamgyong and Gyeongsang City descend from B grade to C grade, Gangwon-do and Jagangdo descend from C grade to D grade and Pyongyang city descend from C grade to D grade. Respectively.

Control of Grade Change Operations in Paper Plants Using Model Predictive Control Method (모델예측제어 기법을 이용한 제지공정에서의 지종교체 제어)

  • Kim, Do-Hoon;Yeo, Young-Gu;Park, Si-Han;Kang, Hong
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.35 no.4
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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.

Model Algorithmic Control for Paper Mills Using Neural Networks

  • Park Jong Ho;Yeo Yeong Koo;Park See Han;Sohn Chang Man
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.36 no.5 s.108
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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.

Dynamic Matrix Control of Grade Change Operations in Paper Mills (제지공정의 모델예측제어)

  • 박종호;여영구;강홍
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2004.11a
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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.

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The Study of Visual Acuity Change in Elementary School (초등학교 아동의 시력변화에 대한 연구)

  • Lee, Hak Jun
    • Journal of Korean Ophthalmic Optics Society
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    • v.7 no.2
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    • pp.217-221
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    • 2002
  • After we compared the Unaided visual acuity and the Corrected visual acuity who were wearing spectacles, all over elementary school in Iksan, we could get conclusions like these. 1. The grades are getting higher, there are more who are 0.6 unaided visual acuity, and getting higher Corrected who were wearing spectacles. 2. There are 30% who have to change their wearing spectacles. 3. Higher grade separated into good or worth visual acuity then lower grade. 4. When the first grade grow up third grade, change of unaided visual acuity increased at 0.2, decreased 0.7 and 1.0, but the case of fourth grade becomes sixth grade shown a little changes unaided visual acuity.

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A numerical study of the influence of rock mass classes boundary on tunnel stability (암반 등급 경계가 터널 안정성에 미치는 영향에 관한 수치해석적 연구)

  • Kim, Gyeomyeon;Jung, Chanmook;Lee, Yongjun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.21 no.6
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    • pp.825-835
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    • 2019
  • When the tunnel is designed, the ground is classified into several grades and the corresponding support system is applied according to the support pattern table. However, a simple pattern application based on rock grade does not take into account the longitudinal stress transitions occurring at rock grade boundaries. In this study, three-dimensional numerical analysis was performed to estimate the stress change in the longitudinal rock grade change of NATM tunnel, and the influence zone of load transfer was investigated using the influence line and trend line. As a result, the downward change of rock grade in the direction of tunnel excavation occurs in the range of 0.35~0.7D from low-strength rock to high-strength rock around the grade change boundary. It is necessary to apply a downward pattern of about 1.0D to the safety direction in consideration of the influence range of 0.35D to 0.7D.

Development of the Goal and the Content System for the Climate Change Education (기후 변화 교육 목표 및 내용 체계 개발)

  • Kwon, Ju-Yeon;Moon, Yun-Seob
    • Hwankyungkyoyuk
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    • v.22 no.1
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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.

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Automated Pressure-Controlled Discography with Constant Injection Speed and Real-Time Pressure Measurement

  • Kim, Hyoung-Ihl;Shin, Dong-Ah
    • Journal of Korean Neurosurgical Society
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    • v.46 no.1
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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.

Domestic Aggregate Quality Status and Mechanical Properties of Concrete According to Quality of Aggregate (국내 골재 품질 현황 및 골재등급에 따른 콘크리트의 역학적 특성에 관한 연구)

  • Min, Choong-Siek;Park, Jong-Ho;Jeong, Yong;Lee, Jae-Hyun;Kim, Yong-Ro;Kim, Hyo-Rak
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.11a
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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.

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Some Characters of Students' Understandings about Tide Concept (조석개념에 대한 학생들의 이해 특성)

  • Kook, Dong-Sik
    • Journal of The Korean Association For Science Education
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    • v.15 no.4
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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.

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