• Korean Journal of Environmental Agriculture
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• v.34 no.4
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• pp.355-358
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• 2015

BACKGROUND: Changes in Korea's agricultural soil properties were analyzed at a four-year interval from 1999 to 2002 on a national scale and used as basis for the determination of the appropriate agricultural policy on maintaining food safety and soil quality. The scope of this study ideally requires sampling thousands of paddy, greenhouse, upland and orchard land across the country, however, due to limitations in economic and manpower resources, it was deemed necessary to reduce sampling site to greenhouse soil. In this study, we try to investigate the applicability of cultivated crops as criteria for selecting representing fields in greenhouse soils.METHODS AND RESULTS: Soil samples were collected from red pepper, oriental melon, watermelon and strawberry cultivated soil. Principal components analysis (PCA) was performed on soil chemical properties of the selected fields: pH, electron conductivity (EC), available phosphate (Av-P₂O₅), organic matter (OM), and exchangeable cation (Ex.-K, Ca, and Mg). Soil chemical properties of oriental melon cultivated soil was separated from red pepper, watermelon, and strawberry cultivated soil on PC1 and red pepper cultivated soil was separated from watermelon cultivated soil on PC2. Position on PC1 was strongly correlated with pH, Ex.-Ca and Ex.-Mg and position on PC2 was strongly correlated with OM and Av-P₂O₅.CONCLUSION: The soil chemical properties of greenhouse soil was assorted amongst the different crops. Therefore, the cultivated crops as a criteria for the selection of representative field in greenhouse soil would be used in the future.

• Journal of Science Education
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• v.42 no.2
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• pp.182-197
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• 2018

The purpose of this study is to identify the difficulties that elementary school teachers face and the atmosphere of school fields in depth in the course of conducting science experiential learning. For this study, we conducted focus group interviews with five elementary school teachers who have had rich experiences in science field studies. Through interviews, the actual state of experiential learning operation, the operation of science experiential learning including planning, progress and evaluation of experiential learning operation. The main results of this study are as follows: Teachers were most concerned about budget, and were burdened with curriculum reconstruction for science experiential learning. In addition, teachers expressed their lack of expert scientific knowledge with science experiential learning, and difficulties with collaboration with science-specialized teachers. In sum, teachers consider budget, site, and administrative convenience first, rather than effects of science experiential learning. The significance of this study is identifying the selection of topics, methods, educational expectations, and problems of science experiential learning topics, which were difficult to identify in previous studies.

• The Journal of the Korea Contents Association
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• v.15 no.3
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• pp.488-498
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• 2015

Form the observation that the successful management and operation of university websites brings about university branding effects, this paper attempts to identify the problems in relation to evaluation elements of university homepages and establish a new evaluation model that allows us to grasp the importance and priority of phased evaluation elements. In particular, we tried to secure the objectivity of the importance of department homepage evaluation elements by using AHP(Analytic Hierarchy Process). Our analysis shows that among 29 evaluation elements of department homepage, mobile service, curriculum, description of department's characteristics, guide to homepage usage/accessibility to site map and differentiated educational method were considered to be relatively important whereas the relative importance of department's slogan, differentiated image and identity, linkage to SNS, Q&A bulletin board, operation of department community, and FAQ was low. Based on the findings from our analysis, we present the basic foundation for successful management and operation of university department homepages along with a few suggestions for vitalizing those hompages.

• Radiation Oncology Journal
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• v.12 no.2
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• pp.253-262
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• 1994

The patterns of the conventional radiation treatment fields and their shielding blocks are analysed to determine the optimal dimension of the MultiLeaf Collimator (MLC) which is considered as an essential tool for conformal therapy. Total 1109 radiation fields from 303 patients (203 from Asan Medical center, 50 from Baek Hosp and 50 from Hanyang Univ. Hosp.) were analysed for this study. Weighted case selection treatment site (from The Korean Society of Therapeutic Radiology 1993). Ninety one percent of total fields have shielding blocks. Y axis is defined as leaf movement direction and it is assumed that MLC is installed on the cranial-caudal direction. The length of X axis were distributed from 4cm to 40cm (less than 21cm for $95\%$ of cases), and Y axis from 5cm to 38cm (less than 22cm for $95\%$ of cases). The shielding blocks extended to less than 6cm from center of the field for $95\%$ of the cases. Start length for ninety five percent of block is less than 10cm for X axis and 11cm for Y axis. Seventy six percent of shielding blocks could be placed by either X or Y axis direction, $7.9\%$ only by Y axis, $5.1\%$ only by X axis and It is reasonable to install MLC for Y direction. Ninety five percent of patients can be treated with coplanar rotation therapy without changing the collimator angle. Eleven percent of cases of cases were impossible to replace with MLC. Futher study of shielding technique is needed for $11\%$ impossible cases. The treatment field dimension of MLC should be larger than $21cm{\times}22cm$. The MLC should be designed as a pair of 21 leaves with 1cm wide for an acceptable resolution and 17cm long to enable the leaf to overtravel at least 6cm from the treatment field center.

• Journal of the Korea Society for Simulation
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• v.24 no.2
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• pp.31-39
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• 2015

Unemployment is related to social issues as well as personal economics activity so various policies have been made to reduce the unemployment rate in many countries. Because of delay inherent in the survey mechanism to collect unemployment data, it takes lots of time to acquire survey unemployment data. To develop proper policies for reducing unemployment rate at the right time, it is quite critical to obtain faster and more accurate information concerning about unemployment level. To remedy this problem, recently an advanced analytics utilizing internet queries is suggested. To examine the potential of Web query information, this research investigates the usefulness of internet activity data to predict Korean unemployment rate. One of selected web-query data(unemployment claim) has a quite strong correlation with unemployment rate. This research employes a time series approach of the ARIMA model that utilizes the information of keyword queries provided by the Naver(Korean representative portal site) trend together with unemployment rate data provisioned from Statistics Korea. With respect to model selection guidelines of mean squared error and prediction error, the model with utilizing the web query information shows better results than the model without such information. This suggests that there is a strong potential for the used method, which needs to be further explored.

• Journal of Korea Foresty Energy
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• v.22 no.2
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• pp.1-17
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• 2003

Populus species have been as a model species in tree breeding and we have enormous varieties resulting from the poplar breeding because of their fast growth performance and short rotation age. New varieties developed in Korea are common italian poplar(P euramericana, I-214, I-476), P euramericana“Eco 28”(Italian poplar No.1) and p. deltoides“Lux”(Italian poplar No.2), which were introduced from foreign countries. As hybrid polars, Hyun-Sasi(p. alba ${\times}$ P. glandulosa No.1, No.2, No.3, No4.), P. nigra x P. maximowiczii and P. koreana x P. nigra val. italica, were developed, and P. davidiana was selected as the result of selection breeding The total plantation areas covered with the new varieties are 935,162ha that include 745,773ha of P. euramericana, 184,636ha of P. alba x P. glandulosa, and other new varieties are 4,735ha. The new poplars are contributed to increase farmer's income as well as bare land tree-planting in Korea. The technologies associated with the poplar species were developed, such as the determination of optimum site for new the poplar species, the crossing method between incompatible poplar species, and the vegetative mass propagation. In the future, poplar species will be considered for phytoremediation species at contaminated areas such as landfill sites or with lives stock's waste water as well as wood production, a shade tree like road-side tree and public park tree.

• Korean Journal of Childcare and Education
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• v.9 no.5
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• pp.407-436
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• 2013

This study, based on understanding the play features of the participants, explores early children's peer-relation strategies of maintaining and altering play frame and understanding the meaning of the strategies. Free play of 5-year-old children's was observed. The child-care center was visited 1 or 2 days a week, from March to October, 2012. The data collected were based from field notes, interviews with participants, their workbooks and more. The participants used strategies such as 'refusing', 'incapacitating', 'interpreting in a way to sympathize', and 'changing the rules of play' to maintain the play, whilst 'tell-on', 'being on the same side', 'accepting 3rd party' features were used to alter play frame. Participants using these various play-frame strategies experienced life implications of 'dialectic of exclusion and selection' and 'quiver of boundary'. This study, specifying efforts of the children to maintain and alter the play frame, will provide an understanding of perception of "social exclusion" to children, which has been viewed negatively in the past. It will also benefit on-site teachers in helping them understand peer-relationship within children and provide a more in-depth intervention for peer-relationship issues.

• Journal of Digital Convergence
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• v.18 no.8
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• pp.69-83
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• 2020

The purpose of this study is to classify the types of street parking in low-rise residential areas. First of all, prior research was reviewed to examine the background of occurance and the process of change of low-rise residential areas. and derive factors that affect the street environment. Next, based on the selection criteria, the residential area of Bangi 2-dong, Songpa-gu was selected as the site of the case and the status analysis was conducted on streets, buildings, and on-road parking. The summary of the results is on-road parking usually occurs on residential streets where social consensus is difficult to reach, suggesting that alternatives to on-road parking in residential areas are needed. Based on the results of the previous analysis, street types were classified considering the characteristics of streets, structures and street parking. Then, the characteristics of each type of street were analyzed and implication for improving the street environment were suggested. In addition, the results of the classification of street types confirmed that different street parking occurred depending on the width of the street and the use of the lower floors, even if it was the same area, and that a solution was needed accordingly.

• Tuberculosis and Respiratory Diseases
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• v.43 no.6
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• pp.903-915
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• 1996

Background: Combination chemotherapy is now considered to be the cornerstone of small cell lung cancer (SCLC). management but the optimal management of limited SCLC is not well defined. The role of thoracic radiotherapy (TRT) is less well established. Recent meta-analyses reports revealed that TRT combined with chemotherapy produce "good" local control and prolonged survival. But other reports that survival was not changed. The liming, dose, volume and fractionation for TRT with the combined chemotherapy of SCLC remains unsettled. In this study, we analyzed the effects according to the timing of thoracic radiotherapy in limited SCLC. Method: All fifty one patients received cytoxan, adriamycin and vincristine(CAV) alternating with etoposide and cisplatin(VPP) every 3 weeks for 6 cycles were randomized prospectively into two groups: concurrent and sequential. 27 patients received 4500cGy in 30 fractions(twice daily 150cGy fractional dose) over 3 weeks 10 the primary site concurrent with the first cycle of VPP(concurrent gorup). 24 patients received 4000 to 5000cGy over 5 or 6 weeks after completion of sixth cycles of chemotherapy(sequential group). Results: 1. Response rates and response duration : Response rates were not significantly different between two groups(p=0.13). But response duration was superior in the concurrent group(p=0.03). 2. Survival duration was nor different between two groups(p=0.33). 3. Local control rate was superior in the concurrent group(p=0.00). 4. Side effects and toxicities: Hematologic toxicities, especially leukopenia, infection and frequency of radiation esophagitis were higher in the concurrent group (p=0.00, 0.03, 0.03). Conclusion: The concurrent use of TRT with chemotherapy failed to improve the survival of limited stage SCLC patients compared with the sequential use of TRT but response duration and local control rate were superior in the concurrent group. Frequency of radiation esophagitis, life threatening hematologic toxicities and infection were more frequent in the concurrent group than sequential group. So, the selection of an optimal schedule of chemotherapy combined with TRT that would lead to a major increase in survival with minimal toxicity is remained to be validated in large scale study in the future.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.2
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• pp.10-17
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• 2011

The paradigm of the use and management of natural resources is changing. Wise use of natural resources can be achieved by enhancing their conservation value and, at the same time, taking them as an opportunity for regional development. It leads to an idea of pursuing regional development by making good use of natural resources. In this paper, natural resources were classified as living species resources, ecosystem and landscape resources, and non-living resources. The resources were divided into 27 detailed analysis indices. The administrative boundaries of 165 municipalities in Korea were defined as spatial analysis units. Finally, a spatial database of natural resources was built. To classify the regional types, we conducted factor analyses with a detailed index of natural resources and a cluster analysis with the factor value. As the result of the factor analysis, six factors have been deduced as follows: forest resources, landscape resources, coastal ecology resources, inland water resources, landform resources, and ecology visit resources. In addition, the cluster analyses were conducted for the points of the factors drawn. The final classification consists of nine groups, and appropriate methods for each regional development have been suggested. Results of this study will contribute to providing fundamental materials for site selection and objective-setting for regional development policies and planning in consideration of natural resources.