• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2004.04a
• /
• pp.97-106
• /
• 2004

The paper making process itself is a typical nonlinear process with complicated dynamics. In the application of advanced control-methods especially for the grade change operations the nonlinear process is linearized to give suitable linear models to be used in the control strategies. However, the use of the linear model is limited within short range containing steady-state operating conditions for grade change operation. In this paper a bilinear model for the nonlinear grade change processes is presented. We can see that the dynamic behavior for grade change operations can be effective analyzed by using multivariable bilinear model.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.35 no.5
• /
• pp.46-52
• /
• 2003

In this work we developed the closed-loop model of a paper machine during grade change with the intention to provide a reliable dynamic model to be used in the model-based grade change control scheme. During the grade change, chemical and physical characteristics of paper process change with time. It is very difficult to represent these characteristics on-line by using physical process models. In this work, the wet circulation part and the drying section were considered as a single process and closed-loop identification technique was used to develop the grade change model. Comparison of the results of numerical simulations with mill operation data demonstrates the effectiveness of the model identified.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2003.11a
• /
• pp.291-305
• /
• 2003

In this work we developed the closed-loop model of a paper machine during grade change with the intention to provide a reliable dynamic model to be used in the model-based grade change control scheme. During the grade change, chemical and physical characteristics of paper process change with time. It is very difficult to represent these characteristics on-line by using physical process models. In this work, the wet circulation part and the drying section were considered as a single process and closed-loop identification technique was used to develop the grade change model. Comparison of the results of numerical simulations with plant operation data demonstrates the effectiveness of the model identified.

• School Mathematics
• /
• v.12 no.4
• /
• pp.667-686
• /
• 2010

The mathematics curriculum revision is currently underway based on the general curriculum revised in 2009. Two of the controversial issues in mathematics curriculum revision are 'grade band' and 'mathematical process'. To consider the introduction of those two aspects in mathematics curriculum, this study compares and analyzes international mathematics curricula focusing on grade band and mathematical process. As a result, grade band is judged to be not necessary, but mathematical process has a potential to provide practical implication for betterment of mathematics textbook and lesson.

• Journal of The Korean Association For Science Education
• /
• v.14 no.3
• /
• pp.312-320
• /
• 1994

The purpose of this study is to analyze the relationship of logical thinking skills and integrated process skills, and to investigate the differences in general tendency of subskills by grade level and gender between Korean middle school students and Japanese one. The performance level of skills was measured using GALT and TIPS II. The results are compared with those of Japan (Mattheis et al., 1992). Summary of the results are as follow. 1. Percentages of formal and transitional stage of males are more than females in developmental level. It has been found out that the males attained significantly higher scores of logical thinking skills than the females in middle school stage. The significant differences in scores by gender show a good correlation with those for Japanese middle school students. Developmental level of Korean middle school students shows a remarkable improvement as they move up from 8th grade to 9 one. The significant differences in developmental level by grade also show a good correlation with those for Japanese middle school students. Total scores of GALT for Japanese middle school students are higher than Korean one, but it has been found nearly same scores for 9th grade in both countries. Scores of subskills of logical thinking skills, except correlational reasoning, for Korean students show lower than those for Japanese students. It could be noted that the combinatorial reasoning is considered to be easiest and the correlational reasoning to be most difficult in both countries. 2. It also has been found out similar pattern for integrated process skills in both countries because the males and females did not examplify significant differences, although males gain somewhat higher scores than females in Korea. Scores of subskills of integrated process skills for Japanese middle school students show higher them Korean one. It could be noted that the identifying variables is considered to be easiest and stating hypothesis to be most difficult in both countries. 3. There was a significant relationship (r= .65) between logical thinking skills and integrated process skills, and there were statistically significant differences of the integrated process skills for developmental level. In integrated process skills, the students who belong to the higher grade levels acquired better score than who belong to the lower grade level. It has been also found remarkable improvement between 8th and 9th grade, and there are significant differences for grade level in both countries.

• Korean Journal of Remote Sensing
• /
• v.23 no.5
• /
• pp.335-346
• /
• 2007

This study is aiming at improving the Environmental Conservation Value Assessment Map(ECVAM) of National Land in Korea. The ECVAM items are composed of legal and environmental/ecological assessments. A popular method applied to ECVAM is an overlay environmental/ecological assessment items. The purpose of this study is to offer complementary items of the ECVAM by examining assessment items. In this study we assessed the ECVAM by five methods. Method 1 is Grade 1 areas of each administrative district; Method 2 is comparing overlapped areas of each assessment items Grade 1, 2 and permission of each assessment items duplication; Method 3 is Grade 1, 2 areas by only singular assessment items; Method 4 is Grade 1 areas only of Method 2; and Method 5 is Grade 2 areas only of Method 2. Method 1 showed Seoul and other metropolitan cities revealed a large proportion of Grade I regions by the legal assessment items. Gang won-Do, showed a large proportion of Grade I regions by the environmental/ecological assessment item. Method 2 showed 93.4% of diameter Grade II(standard for stability); forest diameter item accounted for 99.9% by Method 3, Method 4 showed 95.7% of forest diameter, and forest density accounted for 66.4% by Method 5. This study contributes to reduce the complexity in the process of manufacturing ECVAM of National Land, and to raise the flexibility in the process of managing and updating this map.

• English Language & Literature Teaching
• /
• v.11 no.2
• /
• pp.51-66
• /
• 2005

This study investigates the feasibility of incorporating student evaluations of peer review interactions into the course grade for an EFL writing course. The use of such evaluations offers a way to grade the process of writing more directly than using writing portfolios alone. Moreover, evaluating peer review interactions highlights the social aspect of writing, which is valuable in the current post-process climate in writing instruction. The 18 members of a semester-long EFL writing course at a Korean university were trained in peer response for one half of a semester; then performed evaluations of peer review interactions during the second half of the semester as part of their writing course. Student evaluations were examined to reveal whether any bias occurred due to relative age, gender, major, or question type. The results revealed no such biases. Therefore, it is suggested that students are capable of providing fair evaluations of peers, which means the evaluations can be factored into the course grade in order to evaluate the social aspect of the writing process.

• Journal of Korean Neurosurgical Society
• /
• v.51 no.1
• /
• pp.31-36
• /
• 2012

Objective : The purpose of this study was to elucidate the anatomical development of physiologic suture closure processes in infants using three dimensional reconstructed computed tomography (CT). Methods : A consecutive series of 243 infants under 12 months of age who underwent three dimensional CT were included in this study. Four major cranial sutures (sagittal, coronal, lambdoidal and metopic suture) were classified into four suture closure grades (grade 0=no closure along the whole length, grade 1=partial or intermittent closure, grade 2=complete closure with visible suture line, grade 3=complete fusion (ossification) without visible suture line), and measured for its closure degree (suture closure rates; defined as percentage of the length of closed suture line divided by the total length of suture line). Results : Suture closure grade under 12 months of age comprised of grade 0 (n=195, 80.2%), grade 1 (n=24, 9.9%) and grade 2 (n=24, 9.9%) in sagittal sutures, whereas in metopic sutures they were grade 0 (n=61, 25.1%), grade 1 (n=167, 68.7%), grade 2 (n=6, 24%) and grade 3 (n=9, 3.7%). Mean suture closure rates under 12 months of age was 58.8% in metopic sutures, followed by coronal (right : 43.8%, left : 41.1%), lambdoidal (right : 27.2%, left : 25.6%) and sagittal sutures (15.6%), respectively. Conclusion : These quantitative descriptions of cranial suture closure may help understand the process involved in the cranial development of Korean infants.

• Journal of The Korean Association For Science Education
• /
• v.15 no.4
• /
• pp.404-416
• /
• 1995

The purpose of this study was to investigate the relationship of the cognitive levels and the science process skills based on the cognitive styles. The subjects of the study were 5-6th grade 790 students sampled by random cluster sampling method in three schools from large cities, small cities, and rural areas respectively. The results are as follows. 1) The field independent students showed significantly higher(p< 0.001) cognitive level than the field dependent ones. 2) The field independent group showed higher formation rate of subskills of the logical thinking skills than the field dependent groups. 3) It was found out that the field independent group attained significantly higher scores of science process skills than the field dependent group in 5th and 6th grade students. 4) The more cognitive levels became higher, the more science process skills were significantly higher(p< 0.001). 5) There were significant(p<0.001) differences among the science process skills for grade levels and three regions. And that there were not significant differences in the science process skills between males and females, 6) The science process skills of the field independent and the formal operational group could be acquired better scores in the science process skills than those who belong to another combinations.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.04a
• /
• pp.1038-1043
• /
• 1997

To adapt the neural network proess for the purpose of determination of optimal utting onditions (optimal cutting speed and feed rate), some selection strategies for the machining factors are necessary, which is considered planning cutting process. In this case, factors that have both nonlinearity and strong relationship must be selected. Although tool grade and chemical properties of workpiece material have strong effect to cutting speed, it's not easy to find a analytic relation between them. In this paper, a mathematical method for determining the optimal amount of cutting (depth of cut, feed rate) is presented by tool goemetry and heat generation during cutting process. And various tool grade and workpiece material groups ase classified based on its chemical properties. Thier chemical composition and hardness are used as input pattern for neural network learnig. The result of learning shows the relationship between tool grade and workpiece material and it is proved that it can be used as a sub-system for automatic process planning system.