• Korean Journal of Environment and Ecology
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• v.30 no.1
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• pp.81-91
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• 2016

This study was performed to investigate and monitor changes in aquatic ecological communities, particularly benthic macroinvertebrates from the upper reaches to the down reaches of Songchu valley before the project of Songchu valley translocation initiates. We aimed to verify the translocation effects of the valley on the aquatic macroinvertebrate communities. A field investigation was conducted over three rounds from November 2012 to August 2013. A total of four sites were selected: one to represent the control site (St. 1), two for the translocation sites (St. 2, 3), and one for the downstream sites (St. 4). Our quantitative sampling revealed that the total number of benthic macroinvertebrates were 3,805, which belong to 62 species, 32 families, 9 orders, 5 classes and 4 phyla. As a result of the community analysis at the control site, dominant index was 0.52(${\pm}0.16$), diversity index was 1.95(${\pm}0.44$), evenness index was 0.81(${\pm}0.04$), and richness index was 2.25(${\pm}0.85$). Thus, the community structure was found to be relatively stable. For the EPT ratio of species and individuals that appeared, the control site showed the highest values at 67.60(${\pm}5.66$)% and 66.30(${\pm}2.06$)% respectively, but its value became lower towards the downstream sites. Upon the statistical analysis of the functional feeding groups, it was found that gathering-collectors and filtering-collectors increased toward the downstream sites while shredders decreased. From the point of habitat-oriented group evaluation, sprawlers decreased and burrows increased toward the downstream sites. According to the analysis using Korea Saprobic Index (KSI), the control site is categorized as grade A with average value at 0.75(${\pm}0.10$). However, the grade gradually falls from A to B toward the lower reaches, as the KSI value increases at the translocation and downstream sites.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.41 no.1
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• pp.35-45
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• 2005

The experiment was conducted to investigate the species composition of catches collected by the bottom trawl on June 24 to 26, 2004 in the southern waters of Korea using a trawler "DONGBAEK" belongs to Yosu National University. The investigation was carried out at the 5 stations and the towing speed was 3.4${\sim}$3.7k't. The catches were composed of 46 species from 37 families, 10 orders and 2 classes for fishes and 2 species, 2 families and 2 orders for Chondrichthyes and 44 species, 35 familes, 8 orders for Osteichthyes. The catches of Perciforms were the highest as 24 species and 18 families for fishes. The catches of Spear squid, Loli해 bleekeri and Red banded lobster, Metanephrops thomsoni were also the highest for mollusca and crustacea as 1 class, 3 species, 3 families, 2 orders, 1 class and 7 species, 5 families, 1 order, 1 class respectively. In the 5 stations, number of individuals and biomass were 1,144 and 376.0kg at ST-1, 908 and 240.3kg at ST-2, 666 and 90.1kg at ST-3, 2,050 and 300..4kg at ST-4 and 561 and 24.7kg at ST-5. The diversity index of each stations ranged between 1.49 and it showed the richness index of 2.13${\sim}$3.48, the evenness index of 0.48${\sim}$0.77 and the dominance index of 0.43${\sim}$0.8. Body length distributio of the dominant specise were 9${\sim}$32cm(fork length) for Japanese horse mackerel, Trachurus japonicus, 7${\sim}$23cm(mantle length) for Common squid, Todarodes pacificus, 9${\sim}$43cm(mantle length) for Spear squid, Loli해 bleekeri, 23${\sim}$36cm(total length) for File fish, Thamnaconus modestus, 10${\sim}$28cm(fork length) for Yellow porgy, Dentex tumifrons, 10${\sim}$36cm(fork length) for Target dory, Zeus faber and 8${\sim}$35cm(fork length) for Red seabream, Pagrus major.

• Journal of Gifted/Talented Education
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• v.24 no.6
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• pp.1001-1024
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• 2014

The purpose of the study is to explore the experiences and meaning of the AP (Advanced Placement) at the specialized school for the highly gifted through the in-depth interview with 39 college students who had graduated from the specialized schools with the AP experiences. It is expected that the AP will be expanded to the students at the Science High Schools from the year of 2015, however, there has been no study to examine the realities of the AP in-depth especially through the voices of the AP participants. Students have taken 8 required and/or selective courses as AP in average. Students usually start to take AP from the second year of the specialized school for the highly gifted, but some start from the first year through the placement test. Numbers of available AP courses vary by subjects, but relatively more courses open in the areas of math and physics. Students' opinions regarding the AP were quite positive. Specifically, the high quality of the AP class and energetic interaction between student and teacher compared to the college classes were preferred by the students. However, it was controversial whether C+ is enough for the pass condition of the AP. Students were using the shortened time by AP in diverse ways, such as early graduation, double majors, exchange students, individual researches, and so on. Most of all, they tried to search for their career interests through the AP experiences. In closing, the present study provides some advices and future directions for the better AP management, including the improvement of administrative system between schools for the gifted and the universities, and the expansion of the number of university which approves the AP system.

• Journal of Korean Society of Forest Science
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• v.17 no.1
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• pp.35-42
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• 1973

Deciduous trees grown naturally in the forest of Korea usually have an irregular Lee-form and their utility has been decreased. In Korea, most of the deciduous stands are distributed in the hinterland. A shortage of the total growing stock made utilization of them necessary in this country even though some difficulties to be cutted and transported are accompanied. Therefore, this study was conducted to select the suitable sampling method for surveying them. The results investigated are as follows. 1. Three locations being 10 hectares in each location for the plots were chosen and surveyed with six $20m{\times}50m$ rectangular sample plots by four types of sampling method below. And the result is shown in Table 1. A. Random sampling by grids B. Random sampling by co-ordinates C. Systematic line plot. D. Sub-sampling 2. One hundred and fifty hectares from all plots were sectioned through the application of aerial photography scaled of 1 : 15,000. The author divided forest types according to diameter class and crown density with mirror stereoscope. The forest types were divided into three classes. Seven sample plots from the area of 150 hectars are systematically arranged and the results investigated on the circular sample point of 0.1 hectare are shown in Table 4. 3. There were no significant differences between results by sampling method and by diameter measurement method (population mean) as shown in Table 3. 4. Random sampling by grid and systematic line plot are better than others. 5. There are more over-estimated values when the circular sample point is used than where the rectangular sample point. 6. As forest stands are irregular, smaller number of sample points will make many errors.

• 대한공업교육학회지
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• v.40 no.2
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• pp.111-129
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• 2015

This study tried to investigate the possibility and expectation effect to organize and operate NCS(national competency standards)-based vocational education curriculum in technical specialized high schools and meister high schools and the perceptions of specialty subject teachers about support plans for effective operation of the NCS-based curriculum. For this, the survey was conducted targeting 286 specialty subject teachers in technical specialized high schools and meister high schools. And the results are as follow: First, the specialty subject teachers in the technical specialized high schools and meister high schools recognized that the positive expectation effect can be obtained through the NCS-based vocational education curriculum and the NCS-based vocational education curriculum should very much be applied to the school curriculum but it is impractical to organize and operate the NCS-based vocational education curriculum as the school curriculum from 2016. Second, the specialty subject teachers in the technical specialized high schools and meister high schools recognized that industrial education needs can be analyzed, industry duties-based educational objectives and contents can be set up, industrial duties-based education can be done, the capability to develop and operate teachers' curriculum can be improved, and the NCS-based curriculum will be effective for industrial and academic cooperation and connection with communities by applying it but the realistic possibility will relatively be low. Third, the specialty subject teachers in the technical specialized high schools and meister high schools recognized that tools for practice should be reorganized and expanded, the number of students targeting practical classes should be reduced by 15 to 20 persons, teachers' field education capability should be strengthened, supply and demand of teachers should be supported, industrial and academic cooperation-based field-centered education should be reinforced, and support of the NCS-based teaching materials to be textbooks should be required in terms of operating schools to operate the NCS-based vocational curriculum effectively. Support of finding jobs and field education which correspond with the NCS-based vocational curriculum should be provided, field instruction by ability of the national competency standards should be supported, field practice education projects about the NCS-based vocational curriculum should be provided and introduction and operation of the industrial employee performance evaluation system should be required in terms of the support plans of relevant organizations.

• Journal of Science Education
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• v.47 no.3
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• pp.238-250
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• 2023

This study aims to explore the effect of an appropriate technology program related to water acquisition and purification on scientific attitudes and creative problem-solving skills in elementary school students. Thus, this study developed a learning program related to the appropriate technology composed of 8 sessions, and some were for exploring water acquisition-related scientific principles and the appropriated technology of Warka Tower, and the others were for conducting water purification-related inquiry experiments, such as Life Straw and Drinkable Book, and the last two sessions were for presenting practical tasks through creative ideas and designs and carrying out the relevant campaign activities. For research subjects, this study selected 51 students from two sixth-grade classes, and after modifying the scientific attitude questionnaire and the creative problem-solving skill questionnaire fit for the environment and situation, this study conducted a paired-sample t-test by applying both the questionnaires before and after this program. In addition, while looking into the correlation between scientific attitudes and creative problem-solving skills, based on the post-test results, this study examined relationships between sub-domains perceived by the students after this program was applied. The results can be summarized as below. Out of all the scientific attitudes, curiosity, openness, cooperation, and creativity showed statistically significant results with an increase in the average value when their overall averages of the pre-test were compared with those of the post-test. With creative problem-solving skills, the domain of mastering a specific area and the domain of divergent thinking showed statistically significant results. The correlation analysis results showed that cooperation out of the scientific attitudes had a significant correlation with all the domains of creative problem-solving skills, especially showing the highest correlation coefficient with such sub-domains as critical and logical thinking. All the four domains of creative problem-solving skills showed a number of significant correlations with the sub-domains of scientific attitudes. Through the research results above, this study has several implications on how and where to apply such appropriate technology-related topics in the future and various responses from students.

• Journal of Intelligence and Information Systems
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• v.16 no.3
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• pp.147-161
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• 2010

As broadcasting and communication are converged recently, communication is jointed to TV. TV viewing has brought about many changes. The IPTV (Internet Protocol Television) provides information service, movie contents, broadcast, etc. through internet with live programs + VOD (Video on demand) jointed. Using communication network, it becomes an issue of new business. In addition, new technical issues have been created by imaging technology for the service, networking technology without video cuts, security technologies to protect copyright, etc. Through this IPTV network, users can watch their desired programs when they want. However, IPTV has difficulties in search approach, menu approach, or finding programs. Menu approach spends a lot of time in approaching programs desired. Search approach can't be found when title, genre, name of actors, etc. are not known. In addition, inserting letters through remote control have problems. However, the bigger problem is that many times users are not usually ware of the services they use. Thus, to resolve difficulties when selecting VOD service in IPTV, a personalized service is recommended, which enhance users' satisfaction and use your time, efficiently. This paper provides appropriate programs which are fit to individuals not to save time in order to solve IPTV's shortcomings through filtering and recommendation-related system. The proposed recommendation system collects TV program information, the user's preferred program genres and detailed genre, channel, watching program, and information on viewing time based on individual records of watching IPTV. To look for these kinds of similarities, similarities can be compared by using ontology for TV programs. The reason to use these is because the distance of program can be measured by the similarity comparison. TV program ontology we are using is one extracted from TV-Anytime metadata which represents semantic nature. Also, ontology expresses the contents and features in figures. Through world net, vocabulary similarity is determined. All the words described on the programs are expanded into upper and lower classes for word similarity decision. The average of described key words was measured. The criterion of distance calculated ties similar programs through K-medoids dividing method. K-medoids dividing method is a dividing way to divide classified groups into ones with similar characteristics. This K-medoids method sets K-unit representative objects. Here, distance from representative object sets temporary distance and colonize it. Through algorithm, when the initial n-unit objects are tried to be divided into K-units. The optimal object must be found through repeated trials after selecting representative object temporarily. Through this course, similar programs must be colonized. Selecting programs through group analysis, weight should be given to the recommendation. The way to provide weight with recommendation is as the follows. When each group recommends programs, similar programs near representative objects will be recommended to users. The formula to calculate the distance is same as measure similar distance. It will be a basic figure which determines the rankings of recommended programs. Weight is used to calculate the number of watching lists. As the more programs are, the higher weight will be loaded. This is defined as cluster weight. Through this, sub-TV programs which are representative of the groups must be selected. The final TV programs ranks must be determined. However, the group-representative TV programs include errors. Therefore, weights must be added to TV program viewing preference. They must determine the finalranks.Based on this, our customers prefer proposed to recommend contents. So, based on the proposed method this paper suggested, experiment was carried out in controlled environment. Through experiment, the superiority of the proposed method is shown, compared to existing ways.

• Korean Journal of Ecology and Environment
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• v.52 no.2
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• pp.105-117
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• 2019

In order to investigate the characteristics of benthic macroinvertebrate communities in the Gihwa stream, a tributary of the Dong River, we surveyed the community and environmental factors in April and November 2013 at 6 sites. The benthic macroinvertebrate taxa represented total 63 species belonging to 29 families, 12 orders, 5 classes and 4 phyla. Total 48 (10~28 in each site) species were collected in April and 44 (13~24 in each site) in November. The number of individuals increased slightly from $560{\sim}2,290m^{-2}$ in April to $806{\sim}3,674m^{-2}$ in November. Chironomidae spp. was dominant species in April and Stenopsyche bergeri was dominant species in November. In the Functional Feeding Groups, Gathering-collector(53.9%) was dominant in April, while Filtering-collector (44.3%) increased in November. Intolerant order category (i.e. EPT species richness) in St.1, St.5 and St.6 increased in November compared to April due to the increase of Trichoptera. St.2, St.3 and St.4, which were located near the fish farm, were low EPT as a whole, but Benthic macroinvertebrate index (BMI) was good state in November than April due to decrease of Chironomidae spp.. The environmental factors in the survey site showed similar tendency except for St.1 between both seasons, and electrical conductivity, salinity, and water width showed seasonal differences. Cluster analysis and Nonmetric multidimensional scaling (NMDS) based on benthic macroinvertebrate community data were divided into two groups according to season. Electrical conductivity, salinity and substrate composition were the most influential factors determining the distribution patterns of macroinvertebrate communities.

• Communications of Mathematical Education
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• v.23 no.4
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• pp.977-998
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• 2009

In this article, we give a comparative study on the last 300 years of USA and Korean tertiary mathematics. The first mathematics classes in United States were offered before July, 1638, but the real founding of tertiary mathematics courses was in 1640 when Henry Dunster assumed the duties of the presidency at Harvard. President Dunster read arithmetics and geometry on Mondays and Tuesdays to the third year students during the first three quarters, and astronomy in the last quarter. So tertiary mathematics education in United States began at Harvard which is the oldest college in USA. After 230 years since then, Benjamin Peirce in 1870 made a major and first American contribution to mathematics and got an attention from European mathematicians. Major change on the role of Harvard mathematics from teaching to research made by G.D. Birkhoff when he joined as an assistant professor in 1912. Tertiary mathematics education in Korea started long before Chosun Dynasty. But it was given to only small number of government actuarial officers. Modern mathematics education of tertiary level in Korea was given at Sungkyunkwan, Ewha, Paichai, and Soongsil. But all college level education opportunity, particularly in mathematics, was taken over by colonial government after 1920. And some technical and normal schools offered some tertiary mathematics courses. There was no college mathematics department in Korea until 1945. After the World War II, the first college mathematics department was established, and Rimhak Ree in 1949 made a major and first Korean contribution to modern mathematics, and later found Ree group. He got an attention from western mathematicians for the first time as a Korean. It can be compared with Benjamin Peirce's contribution for USA.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.2
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• pp.60-68
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• 2008

Three land-use limitations including water hazard, soil erosion and fallow potential were evaluated to define an unfair area. Landscape indices in the unfair areas, defined by evaluations before and after landscape enhancement, were computed by Fragstats v3.3 and compared in order to propose a landscape enhancement plan. The results are as follows: First, as a result of the land evaluation, 388.56ha was analyzed for the 1st class(S1), 623.25ha for the 2nd class(S2), 138.08ha(S3s: 82.47ha, S3e: 51.88ha) for the 3rd class(S3), 230.44ha(N1w: 194.91ha, N1e: 23.09ha, N1es: 13.94ha) for the 4th class(N1), and 67.91ha(N2w: 60. 89ha, N2es: 7.02ha) for the 5th class(N2). The classes under the 3rd class(including the 3rd class) were determined as an unfair area, and proposed landscape enhancement for them. Second, it was proposed that unfair areas with potential water hazards(N1 w, N2w) be restored as a wetland and buffer zone. At this point, the farmers owning these fields could be compensated using the direct payment for landscape conservation(DPLC). Areas witha relatively lower slope(S3e) or a steep slope(N1e) containing soil erodibility potential were proposed to be restored as a sod-culture-applied field and substitute vegetation or potentially natural vegetation, respectively. The unfair areas having fallow potential(S3s, N1es, N2es) were proposed to apply special use crops for the S3s fields, native plants for the N1es fields, and intended fallow for the N2es fields. Third, after landscape enhancement, theforest had higher values in the indices of NP, PLAND, LSI, IJI, and TCA, while paddy and upland had lower values in most indices except NP and LSI. The forest patches increased and were more plentiful with their restoration and had much greater possibility to join with nearby patches. With continued restoration, forest patches will have a large core area and small number of patches due to the conglomeration of patches, which positively influences the species of diversity in the forest patches.