• Hwankyungkyoyuk
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• v.3 no.1
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• pp.141-152
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• 1992

The purpose of this study is to search for the ways to diversify Outdoor/Environmental Education Program in the Nature Study Center(NSC), especially for the middle school students. For this study, various research methods such as literature review, questionnaire survey (448 students, 11 middle school teachers, 19 NSC staffs), interview and participant observation are used the process of this study consists of two steps. The first step is to define research questions through pilot survey and the second is to investigate the research questions, in the form of hypotheses through main survey. Nine hypotheses are formulated. Six are related with program elements (educational goals, student characteristics, staff resources, teaching methods, instructional resources, contents). three are related with program implementation process(preplan, implementation, post-evaluation). The hypotheses are tested and alternatives for program improvement are proposed. 1. Educational goals : Educational goals of NSC should be focused on Outdoor /Environmental Education and each NSC should specialize on its own theme. The objectives of every sub-program should be unified toward educational goals. 2. Student characteristics: The Outdoor/Environmental Education Program should reflect student characteristics: sex, urban/rural origins, normal/handicapped, number of visit and so on. 3. Staff resources : Provide qualified staff with professional knowledge and positive attitudes, reeducate staffs periodically, reduce management staff and increase teaching staffs. Provide permanent and well paid position, encourage and give opportunities and the middle school teachers to participate in program. 4. teaching method: Increase outdoor classes two way communication between teaching staffs and students adopt more open ended teaching method so that students can exercise coworks in small groups. 5. Instructional resources: Diversify NSC sites(mountains, coastal areas, urban areas and so on), teaching media (audio/visual equipments, graphic design of signs). Consider design for handicapped and integrate indoor and outdoor educational facilities. Plan nature trails with separate themes, allign nature trail so that it passes through diverse environments. 6. Content : Reflect characteristic site potential specialize on day or night program, on seasonal program, and on site specific social issues(such as interpreting of environmental damages around the NSCs). 7. Preplan: Get Information and know about visiting students in advance. Discuss with middle school teachers and adjust program weeks before visits if many or all of the students had already visited a NSC. arrange a visit to other NSC. Provide an introductory class for the teachers and students before they visit a NSC. 8. Implementation: During NSC visit and classes apply various and appropriate techniques to collect in formation for later evaluation. Improve NSC provided evaluation sheet so as to reflect student characteristic. Compare with formal education and investigate on effects of NSC program. 9. Post-evaluation: Formalize a post-evaluation process and organization. During the winter vacation, develop new programs based on the post-evaluationacation, for the next year. Also, have comparative evaluation meetings of staff from various NSCs during the winter vacation while there is no visitors and classes.

• 월간산업보건
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• s.8
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• pp.4-30
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• 1988

Examination of working environments was conducted to get more detailed data about harmful working environments and to make a contribution to more effective management. Study was carried out on 722 factories located in Taegu city and eight counties in Kyungpook Province, Korea, for a period of one year, from February 1 to December 30, 1986. The total number and proportion of workers exposed to harmful material was 37,697, 45.2% among 83,368 workers. The results according to exposed material were as follows: 1. In the case of noise, proportion of exceeding the 8-hour TLV was 59%, Included were nail-cutting in assembly metal manufacturing industry and weaving process in textile. 2. Dust in mill process of coal manufacturing industries exceeded the TLV of second class of dust at all parts and exceeded the TLV at 6% as a whole.: 3. The fields of industry lower than 70 lux of illumination were storage equipment of food, auto-winder of textile, painting of wood wares and coal mixing, and 44% of all cases was lower than standard. 4. As a result of temperature index investigation(WBGT), about 12% of all sujects exceeded limit value. Included parts were rolling machine and reducing room. 5. In the case of organic solvents, TLV was exceeded at about 8%, The parts exceeded TLV according to materials belonged to this category were as follows. 1) Toluene: adhesive work in assembly metal manufacturing 2) Xylene: printing and paint mixing in chemical manufacturing 3) Methyl ethytl ketone: paint mixing in all parts examined and coating machine partially in chemical manufacturing 4) Methyl isobutyl ketone: printing in chemical manufacturing 5) Acetone: vapor polishing in assembly metal manufacturing 6. Among specified chemical materials, the concentration of HC1 in the air in metal assembly manufacturing factory exceeded TLV. in one of three assembly metal manufacturing examined. Others, such as benzene, acetic acid, formic acid, sodium hydroxide, formalin, ammonia, copper, chromate etc. were lower than TLV in its indoor atmospheric concentration. As a whole, the proportion of exceeding TLV was about 0.8% 7. The concentrations of inorganic lead were lower than TLV in all parts examined. The results of this investigation show the fact that current management of working environments is not satisfactory, and so more active management is needed.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.3
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• pp.1-14
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• 2008

Mass transit information should contribute many benefits to users. Especially transportation information technology is developing highly with information technology in Korea recently. Hereafter it is expected to provide customized transportation information to users individually with the advent of ubiquitous age in earnest. This public transportation information service can be realized by path finding algorithms in public transportation networks including travel and transfer attributes. In this research, multi objectives such as travel time, transfer time, and number of transfer and so on are constructed with the primary facts influencing users. Moreover, the method reducing user's path finding alternatives arbitrarily is proposed by selecting the best alternative which provides maximum utility to users among non dominated paths. Therefore, the ultimate goal of this study proposes a multi objective shortest paths finding algorithm which can take into account multiple user classes in a transit network with multiple travel modes. The proposed algorithm is demonstrated based on the two case studies - a small toy network and the large-scaled Seoul Metropolitan subway network.

• Journal of the Korean Society for Railway
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• v.15 no.4
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• pp.370-375
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• 2012

In order to apply Interior Permanet Magnet Synchronous Motor(IPMSM) to the propulsion system of the railway transit, 110kW class IPMSMs with high-power density are designed as a concentrated winding model and a distributed winding model in this study. The concentrated winding model designed in this study is 6 poles/9 slots and the distributed winding model is 6 poles/36 slots. In general, the eddy current losses in the permanent magnets of IPMSM are caused by the slot harmonics. The thermal demagnetization of the magnet by the eddy current losses at high rotational speed often becomes one of the major problems in the IPMSM with a concentrated windings especially. A design to reduce eddy current losses in permanent magnet design is important in IPMSM for the railway vehicle propulsion system which requires high-speed operation. Therefore, a method to devide the permanent magnet is proposed to reduce the eddy current losses in permanent magnet in this study. Authors analyze the variation characteristics of the eddy current losses generated in permanent magnet of the concentrated winding model by changing the number of the division of the permanent magnets.

• Korean Journal of Environment and Ecology
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• v.27 no.3
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• pp.344-356
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• 2013

This study is a continuation of the 22 year consecutive study (1972~1993) to monitor community dynamics of forest in Mt. Kwanak. This study was intended to provide basic data for urban forest management in the future by analyzing actual changes in vegetation structure of forest in Mt. Kwanak caused by urban environmental changes. For the past 39 years (1972~2010), average temperature increased by approximate between 1.1 and $1.7^{\circ}C$ and soil acidification (pH $5.40{\rightarrow}4.50$) and contents of $K^+$ ($0.67{\rightarrow}0.25$) and $Ca^{{+}{+}}$ ($3.20{\rightarrow}0.87$) apparently tended to decrease. According to analysis importance percentage and DBH class of community types classified based on DCA, the succession stopped at Quercus mongolica for 39 years. In addition, the succession was expected to be held at Q. mongolica or to shift from Pinus densiflora to Q. mongolica and from Q. acutissima to Q. serrata. Size of trees growing in forest of Mt. Kwanak increased but the number of species and population of trees showed a downward trend for the 39 years and Styrax japonica and Sorbus alnifolia, which are indicator species, increased their dominance continuously. Decrease in contents of $K^+$, $Ca^{{+}{+}}$, and $Mg^{{+}{+}}$ and soil acidification for the past 39 years was found to affect degradation of vegetation structure in Mt. Kwanak.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.2
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• pp.23-34
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• 2012

As the quality of life grows, the role of cultural facilities in urban areas is becoming more important. However, due to various reasons, the location of these facilities shows the geographical imbalance between urban regions. Even though provision of road network can improve this kind of urban problem, in many countries, the provision of urban infrastructure plays a role which is magnifies the cultural gap between regions and socio-economic classes. The findings of this study are as follows. First of all, the inequality of accessibility to cultural facilities is shown over the period. Cross-sectional data shows that the higher the income of a region, the higher the accessibility index(AI) of the zone to cultural facilities at any time. Next, the provision of road network contributes the improvement of AI of high income region. Finally the provision of new facilities has a tendency that these kind of facilities are located to make AI of high income zone better. It means that the decision making by city government intensifies the geographical inequality. This result would be very useful in the decision making process for determining the number and the location of cultural facilities and other similar urban infrastructure as well. Also it will be helpful for the selection of optimal location which considered not only physical distances but also social equalities.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.2
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• pp.113-125
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• 2012

This research is aimed at evaluating the land surface characterization of KOMPSAT-3A middle infrared (MIR) data. Airborne Hyperspectral Scanner (AHS) data, which has MIR bands with high spatial resolution, were used to assess land surface temperature (LST) retrieval and classification accuracy of MIR bands. Firstly, LST values for daytime and nighttime, which were calculated with AHS thermal infrared (TIR) bands, were compared to digital number of AHS MIR bands. The determination coefficient of AHS band 68 (center wavelength $4.64{\mu}m$) was over 0.74, and was higher than other MIR bands. Secondly, The land cover maps were generated by unsupervised classification methods using the AHS MIR bands. Each class of land cover maps for daytime, such as water, trees, green grass, roads, roofs, was distinguished well. But some classes of land cover maps for nighttime, such as trees versus green grass, roads versus roofs, were not separated. The image classification using the difference images between daytime AHS MIR bands and nighttime AHS MIR bands were conducted to enhance the discrimination ability of land surface for AHS MIR imagery. The classification accuracy of the land cover map for zone 1 and zone 2 was 67.5%, 64.3%, respectively. It was improved by 10% compared to land cover map of daytime AHS MIR bands and night AHS MIR bands. Consequently, new algorithm based on land surface characteristics is required for temperature retrieval of high resolution MIR imagery, and the difference images between daytime and nighttime was considered to enhance the ability of land surface characterization using high resolution MIR data.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.562-574
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• 2012

Simulation validation techniques which have been employed in most studies are statistical analysis, which validate a model with mean or variance of throughput and resource utilization as an evaluation object. However, these methods have not been able to ensure the reliability of individual elements of the model well. To overcome the problem, the weighted F-measure method was proposed, but this technique also had some limitations. First, it is difficult to apply the technique to complex system environment with numerous values of interarrival time because it assigns a class to an individual value of interarrival time. In addition, due to unbounded weights, the value of weighted F-measure has no lower bound, so it is difficult to determine its threshold. Therefore, this paper propose weighted F-measure technique with cluster analysis to solve these problems. The classes for the technique are defined by each cluster, which reduces considerable number of classes and enables to apply the technique to various systems. Moreover, we improved the validation technique in the way of assigning minimum bounded weights without any lack of objectivity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.389-402
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• 2020

This study aimed to develop an educational program for improving the learning competencies of major courses for Chinese graduate students who account for more than 70% of international students in Korea. In this study, the program was developed using Caffarella and Daffron's interactive model. Due to the internationalization of education, the number of foreigners who study in Korea for degree courses has already exceeded 100,000, but the dropout rate has increased due to the maladjustment to university life. More specifically, they face difficulties in academic achievement because of a lack of understanding lecture contents, conducting research, and presenting in class. Therefore, this study surveyed the Chinese students in the graduate course to identify the difficulties and needs in their study of major courses and to reflect those needs (major knowledge, communication, assignment writing, and presentation) in program development. This study focused on developing an educational program for improving their learning competencies of major courses rather than simply improving Korean language skills or adapting to university life. The results of the study are expected to help Chinese Graduate students perform well in their major course studies and make their study abroad successful.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.11 s.353
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• pp.128-140
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• 2006

In the IEEE 802.16 Wireless MAN standard specifies the air interface of fixed point-to-multipoint broadband wireless access systems providing multiple services. Among the service classes supported between the base station and subscriber stations in the wireless MAN, the best effort service class is ranked on the lowest position in priority and is assisted by a MAC scheme based on reservation ALOHA. The wireless MAN standard, however, does not reveal every detail of the MAC scheme but only describes the skeleton of the MAC scheme. Focusing on the amount of resource that a subscriber demands by a request and the amount of resource that the base grants to a request we thus present a number of resource demand rules and resource grant rules. Also, we construct a candidate MAC scheme by implanting a pair of resource demand and grant rules into the skeleton of the MAC scheme. Meanwhile a difficult situation for the best effort service is expected wherein only scarce resource is available after most of the resource is already preempted by other services. Perceiving such a situation, we evaluate the throughput and delay performance of each candidate MAC scheme. Especially we develop an analytical method to approximately calculate the throughput in the saturated environment. From the numerical results, we observe that the candidate MAC scheme which adopts the non-gated exhaustive demand rule paired with the full grant rule attains superior performance at the expense of the fairness.