• Journal of The Korean Association For Science Education
• /
• v.34 no.4
• /
• pp.375-383
• /
• 2014

The purpose of this study is to find out how middle school students evaluate scientific information in terms of hypothetico-deductive reasoning. A total of 66 middle school students completed a paper-and-pencil test on scientific information evaluation and 14 of them were individually interviewed for triangulation. The test includes six topics related to scientific or pseudoscientific information, and questions about each topic were sequenced based on a hypothetico-deductive reasoning. The hypothetico-deductive process consists of three steps: identifying predictions made by explanations in the information, identifying data actually obtained, and determining the fit between predictions and data to judge the validity of the explanations. Data analyses have focused on students' response types at each step, whether students used hypoethetico-deductive reasoning, and students' preference to evidence types in making decisions. The middle school students in this study answered the questions in various ways based on how they used the information given or personal knowledge and beliefs. A small portion of students evaluated information based on hypothetico-deductive reasoning. These students tended to give priority to scientific data in determining the validity of the information. On the other hand, students who did not use hypoethetico-deductive reasoning tended to prefer first-hand experience in the decision. The results provide implications for science lessons and the curriculum for scientific literacy. Further research should include student evaluation of the validity of data and other types of reasoning.

• Journal of The Korean Association For Science Education
• /
• v.33 no.5
• /
• pp.963-980
• /
• 2013

The purpose of this study was to investigate the process of constructing pre-service teachers' scientific knowledge information through collective intelligence. We selected the 'Appropriate Technology' (A.T.) as the subject for formation of scientific knowledge. Twenty nine pre-service teachers of the course 'Scientific Thinking and Writing in Science Education' were allowed to freely post information whenever they wanted. They presented their full opinions, interacted with each other, and assessed the other' information on the website for a month. The way of posting was as follows. After one pre-service teacher had written the information about A.T. on the website, the other assessed the text and added or modified the writing. This process continued. We analyzed every writing they posted and questionnaire which contained the reason why they modified the text. The result was as follows. Pre-service teachers formed collective intelligence through four stages. First, pre-service teachers started to find the information related to the subject and they just added the information behind the other's writing. In the second stage, information was added, too. But the difference was that the information they selected carried values for having certain views. Third, they organized their writings with logical and critical thinking. Finally, they revised their overall writing. The results showed that students could develop their critical thinking and they could learn the way of communication from the process of collective intelligence. We found the forming process of knowledge by collective intelligence, and explored the various involving patterns and thinking activities in the process. Based on this research, we expect the improvement of students' logical and critical thinking through the various classes using collective intelligence.

• The KIPS Transactions:PartD
• /
• v.17D no.2
• /
• pp.87-102
• /
• 2010

A vast amount of traffic data is produced every day from detection devices but this data includes a considerable amount of errors and missing values. Moreover, this information is periodically deleted before it could be used as important analysis information. Therefore, this paper discusses the implementation of an integrated traffic history database system that continuously stores the traffic data as a multidimensional model and increases the validity and completeness of the data via a flow of processing steps, and provides a what-if analysis function. The implemented system provides various techniques to correct errors and missing data patterns, and a what-if analysis function that enables the analysis of results under various conditions by allowing the flexible definition of various process related environment variables and combinations of the processing flows. Such what-if analysis functions dramatically increase the usability of traffic data but are not provided by other traffic data systems. Experimantal results for cleaning the traffic history data showed that it provides superior performance in terms of validity and completeness.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.20 no.4
• /
• pp.419-425
• /
• 2014

The current work investigated the variation of numerical solutions according to the grid number, the distance of the first grid point off the ship surface, turbulence modeling and discretization. The subject vessel is KVLCC. A commercial code, Gridgen V15 and FLUENT were used the generation of the ship hull surface and spatial system and flow computation. The first part of examination, the effect of solutions were accessed depending on the grid number, turbulence modeling and discretization. The second part was focus on the suitable selection of the distance of the first grid point off the ship surface: $Y_P+$. When grid number and discretization were fixed the same value, the friction resistance showed differences within 1 % but the pressure resistance showed big differences 9 % depending on the turbulence modeling. When $Y_P+$ were set 30 and 50 for the same discretization, friction resistance showed almost same results within 1 % according to the turbulence modeling. However, when $Y_P+$ were fixed 100, friction resistance showed more differences of 3 % compared to $Y_P+$ of 30 and 50. Whereas pressure resistance showed big differences of 10 % regardless of turbulence modeling. When turbulence modeling and discretization were set the same value, friction, pressure and total resistance showed almost same result within 0.3 % depending on the grid number. Lastly, When turbulence modeling and discretization were fixed the same value, the friction resistance showed differences within 5~8 % but the pressure resistance showed small differences depending on the $Y_P+$.

• Investigative Magnetic Resonance Imaging
• /
• v.13 no.1
• /
• pp.22-30
• /
• 2009

Purpose : Patient motion during magnetic resonance (MR) imaging is one of the major problems due to its long scan time. Entropy based post-processing motion correction techniques have been shown to correct motion artifact effectively. One of main limitations of these techniques however is its long processing time. In this study, we propose several methods to reduce this long processing time effectively. Materials and Methods : To reduce the long processing time, we used the separability property of two dimensional Fourier transform (2-D FT). Also, a computationally light metric (sum of all image pixel intensity) was used instead of the entropy criterion. Finally, partial Fourier reconstruction, in particular the projection onto convex set (POCS) method, was combined thereby reducing the size of the data which should be processed and corrected. Results : Time savings of each proposed method are presented with different data size of brain images. In vivo data were processed using the proposed method and showed similar image quality. The total processing time was reduced to 15% in two dimensional images and 30% in the three dimensional images. Conclusion : The proposed methods can be useful in reducing image motion artifacts when only post-processing motion correction algorithms are available. The proposed methods can also be combined with parallel imaging technique to further reduce the processing times.

• Korean Journal of Environment and Ecology
• /
• v.15 no.3
• /
• pp.276-285
• /
• 2001

This report surveyed degradation of forest environment and rehabilitation in Ashio of Japan. Since 1880, a large scale forestry in this area has been destroyed by sooty smoke, and the local government invested heavily to rehabilitate the damaged forestry and denuded mountains. These degradations are due to complex operations, such as sulfurous acid gas from copper refinery, forest fires, steep slope and disadvantageous climate. The rehabilitation works on degraded forestry(2,399ha) were undertaken by tree planting fur three years from 1897. However, forest degradation and disasters were continued, and the total damaged areas were about 2,400~3,000ha in 1956. A Manual labor method, a Helicopter method and also Combination of manual labor and helicopter method had been adopted to rehabilitation works from 1945 to 1996, while 828.19ha of the degraded mountains was rehabilitated. Total investment for those projects was 80 billion yen. A debris control dam, a soil arresting structure, a vegetation-block, a vegetation sack measures and tree planting have implemented significantly fur the method of rehabilitation. An objective of manual labor works is a complete rehabilitation on each place through 3 stage working. The revived green areas accounted fur 49% of the total, and the entire afforest areas are less than 10%. In coming 25 years, an amount of 21.3 billion yen will be invested to rehabilitate 564ha of degraded mountain lands. However, it is impossible to estimate that how long it will take until the whole degraded mountain lands are completely rehabilitated. Rehabilitation works in Ashio may be applicable to environmental restoration and revegetation in the abandoned coal-mine lands of Korea.

• Korean Journal of Environment and Ecology
• /
• v.30 no.5
• /
• pp.803-809
• /
• 2016

In order to elucidate the ecological responses of B. latissimum under global warming situation and prepare the conservation measures, we cultivated the plant within control(ambient $CO_2+$ambient temperature) and treatment(elevated $CO_2+$elevated temperature) from 2010 to 2011. Rising $CO_2$ concentration was treated with 2 times and temperature increased with $2.0^{\circ}C$ above than control. As a result, Growth response has received more the effect of $CO_2+$Temperature rising than light, moisture, nutrients, and it was grow well in $CO_2+$temperature rise sphere when many nutrients, and it was grow well in $CO_2+$temperature rise sphere when many nutrients. No. of leaves were many number in the treated group compared to the control at a low light gradient and high nutrient gradient, leaf width was narrow in the treatment compared to the control in the middle gradient of light and nutrients. Shoot length, petiole length, lamina length was no difference between control and $CO_2+$temperature rise sphere. Based on the results of this study, in order to preserve the B. latissimum in future climate, we should be supply of nutrients(containing ${NH_4}^+$, $NO_3$, $P_2O_5$, $K_2O$, etc.) in the habitat of the B. latissimum, and must ensure that the habitat of B. latissimum is not destroyed. Also, We should be find similar area with habitat of the B. latissimum, restoring, expanding.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.7
• /
• pp.18-25
• /
• 2014

To increase wireless capacity, the concurrent use of multiple wireless interfaces on different frequency bands, called aggregation, can be considered. In this paper, we focus on aggregation of multiple Wi-Fi interfaces with packet-level traffic spreading between the interfaces. Two aggregation schemes, link bonding and multipath TCP (MPTCP), are tested and compared in a dualband Wi-Fi radio system with their Linux implementation. Various test conditions such as traffic types, network delay, locations, interface failures and configuration parameters are considered. Experimental results show that aggregation increases throughput performance significantly over the use of a single interface. Link bonding achieves lower throughput than MPTCP due to duplicate TCP acknowledgements (ACKs) resulting from packet reordering and filtering such duplicate ACKs out is considered as a possible solution. However, link bonding is fast responsive to links' status changes such as a link failure. It is shown that different combinations of interface weights for packet spread in link bonding result in different throughput performance, envisioning a spatio-temporal adaptation of the weights. We also develop a mathematical model of power consumption and compare the power efficiency of the schemes applying different power consumption profiles.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.5 no.3
• /
• pp.99-106
• /
• 2002

The application method of GIS for planning of forest road network can be save the efforts and cost by frequently change of forest road and evaluation the forest road route before construction. The purpose of this study is to suggest the proper method for planning an optimal forest road network in mountains forest using geographic information system(GIS) in the national forest of Mt. Kumsan at Namhae-gun, Gyungsangnam-do. In the forest road network planning by the minimum longitudinal gradient, The total length was 20.41km, and road density was 6.92m/ha. In the forest road network planning by mixed with the minimum longitudinal gradient and the maximization of investment effect, The total length was 21.15km, and road density was higher than that of the minimum longitudinal gradient as 7.17m/ha. The road length overlapped by cost path was more short than 3.52m/ha of the minimum longitudinal gradient as 1.73km. So, it appeared that forest road has an high effectiveness in yarding function. Therefore, it considered that the geographic information system could provide an effective and resonable solutions for planning of optimal forest road network.

• Management & Information Systems Review
• /
• v.32 no.5
• /
• pp.119-134
• /
• 2013

The purpose of this study was to explore the labor relations and job attitudes on KORAIL's employees. The subject of the study was the members of the Gyeongbuk Headquarters of Korea Railroad Corporation(KORAIL). For the purpose of analysis, a survey was conducted for 155 members of KORAIL Gyeongbuk Headquarters, and 119 questionnaires were used for the final analysis. The results of the analysis are as follows: First, there are 3 powerful parties in the KORAIL system of labor relations as Union, Management and Goverment. The KORAIL system of labor relations is very unstable and rigid. The labor union of KORAIL engaged in a desperate struggle against the management. Second, there are significant differences in job satisfaction, communication, organizational commitment, job attitudes between union members and non-union members. These results indicate that establish a labor-management community culture, communication need to be more activated. The activation of communication can contribute to building confidence in labor-management relationship.