• Korean Journal of Childcare and Education
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• v.2 no.1
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• pp.65-88
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• 2006

This study intended to activate public education, researched and analyzed real conditions of preschool education to know desirable directions of public education and help parents recognize public education. The final purpose is to offer basic materials to reestablish preschool education in the public education system. First, parents' recognition concerning preschool education in the public education system was much different from that of teachers. As for definitions of preschool education as a public education, parents understood that it means 'the nation and self-governing bodies manage aid both the public and private kindergartens', and teachers recognized that it means that 'the nation and self-governing bodies not only found operate public kindergartens but also aid manage educational funds of private kindergartens. Second, the examination of educational environments of kindergartens told that teachers and parents thought that opportunity to enter the kindergarten is not equal for all children in our country, and quality of kindergarten teachers is satisfactory. Also, they thought that curriculums of preschool educational organs have been set well according to children's developmental stages, education quality is different according to preschool education organs' foundation-types. They recognized that facilities and apparatus of preschools are satisfactory, security and neatness of preschools are satisfactory, too. Third, the examination of developmental directions of preschool education as a public education proved following facts; as for foundation-types of kindergartens in the future when promoting preschool education as a public education, parents answered financial support and supervision by the government, teachers answered aid and management of operational fees as well as support for teacher personnel expenses.

• Journal of Environmental Impact Assessment
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• v.29 no.5
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• pp.350-362
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• 2020

In this study, nano Fe°-impregnated biochar (INPBC) was prepared using pruning residues and one-pot synthetic method and evaluated its performance as an amendment agent for the stabilization of arsenic-contaminated soil. For the preparation of INPBC, the mixture of pruning residue and Fe (III) solution was heated to 220℃ for 3hr in a teflon-sealed autoclave followed by calcination at 600℃ under N₂ atmosphere for 1hr. As-prepared INPBC was characterized using FT-IR, XRD, BET, SEM. For the stabilization test of as-prepared INPBC, As-contaminated soils (Soil-E and Soil-S) sampled from agricultural sites located respectively near E-abandoned mine and S-abandoned mine in South Korea were mixed with different of dosage of INPBC and cultivated for 4 weeks. After treatment, TCLP and SPLP tests were conducted to determine the stabilization efficiency of As in soil and showed that the stabilization efficiency was increased with increasing the INPBC dosage and the concentration of As in SPLP extractant of Soil-E was lower than the drinking water standard level of Ministry of Environment of South Korea. The sequential fractionation of As in the stabilized soils indicated that the fractions of As in the 1st and 2nd stages that correspond liable and known as bioavailable fraction were decreased and the fractions of As in 3rd and 4th stages that correspond relatively non-liable fraction were increased. Such a stabilization of As shows that the abundant nano Fe° on the surface of INPBC mixed with As-contaminated soils played the co-precipitation of As leaching from soil by surface complexation with iron. The results of this study may imply that INPBC as a promising amendments for the stabilization of As-contaminated soil play an important role.

• Korean Journal of Environment and Ecology
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• v.25 no.2
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• pp.189-210
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• 2011

As a part of improving the effect of stream restoration, the study selected 90 domestic natural streams that are not damaged and researched their riparian vegetations. Among them, the results of streams, whose naturalized ratio were more than 5 % and valley type flood plains were not developed, were excluded. By using the results of final 49 streams, plant communities and companion species that commonly appeared in high frequency, depending on stream type, were drawn. The result revealed that Quercus mongolica community, Hemiptelea davidii community and Salix koreensis community were representative in the mid-northern district (latitude: N $37{\sim}37.9^{\circ}$) with Salix koreensis community in the central district (latitude: N $36{\sim}36.9^{\circ}$) and Quercus serrata community in the southern district (latitude: $34{\sim}35.9^{\circ}$). For the stream type depending on altitude, Quercus serrata community and Phragmites japonica community were representative in the altitude of 200~500 m and there was no stream, in which flood plain is developed naturally, in the altitude of more than 500 m. In addition, the study drew representative communities depending on width of stretches of water at mean water level indicating the size of stream. Quercus serrata community was major vegetation at sites which are less than 20 m wide and Salix koreensis community was common at sites which are more than 20 m and less than 100 m wide of stretches of water at mean water level. Meanwhile the major vegetations at sites which are more than 100 m wide were Salix koreensis community, Morus bombycis community and Salix nipponica community. The study selected the kind of tree for planning riparian forest in flood plain by stream type on the basis of the result and suggested tree planting pattern that can be used in actual work by referring to the result of hydraulic review.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.3
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• pp.56-71
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• 2013

This study was carried out to investigate the construction background of multi-functional vacant grounds in the rear gardens of Kyeongbok Palace and Kyeongun Palace, by understanding the building history of multi-functional vacant ground during the Joseon Dynasty with a special reference to the places formed in the period of King Kojong. The multi-functional vacant grounds in the Palace were the important element from the political aspect of Joseon Dynasty, and became an infrastructure of a state - run organization. The vacant space between Kwangyeonlu(廣延樓) and Haeonjeong, the whole region of Yeolmujeong(閱武亭), Seochongdae(瑞蔥臺), and Chundangdae(春塘臺) were investigated as the multi-functional places, where the events were held for the royal family in the Changdeok Palace after the establishment of the Joseon Dynasty. Various events such as the archery competition, official examination and military training were held at the places. After the inauguration of King Kojong, Kyeongmudae(京武臺) was made in the process of the reconstruction of the Kyeongbok Palace. The Kyeonghee Palace was used as the off-palace rear garden after the year that King Kojong returned to the Kyeongun Palace. The characteristics of two spaces were to apply the space organization of the Changdeok Palace into the rear garden outside of Sinmumun(神武門), Kyeongmudae at Kyeongbok Palace and the pedestrian overpass was established to connect the spaces efficiently in Kyeonghee Palace. Especially, the multi-functional vacant ground in the rear garden during the period of King Kojong functioned as the place to show off the internal and external independence of a nation and to show the authority and dignity of King at the point of time that accelerated the plundering Joseon Dynasty by Japanese imperialism powers, beyond the meaning of national event space that had existed before, such as official examination or archery test. In addition, the fact that the multi-functional vacant ground used as training place for military exercise where many people were mobilized was considered to reflect the contemporary situation.

• Journal of Intelligence and Information Systems
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• v.23 no.2
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• pp.1-17
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• 2017

The deep learning framework is software designed to help develop deep learning models. Some of its important functions include "automatic differentiation" and "utilization of GPU". The list of popular deep learning framework includes Caffe (BVLC) and Theano (University of Montreal). And recently, Microsoft's deep learning framework, Microsoft Cognitive Toolkit, was released as open-source license, following Google's Tensorflow a year earlier. The early deep learning frameworks have been developed mainly for research at universities. Beginning with the inception of Tensorflow, however, it seems that companies such as Microsoft and Facebook have started to join the competition of framework development. Given the trend, Google and other companies are expected to continue investing in the deep learning framework to bring forward the initiative in the artificial intelligence business. From this point of view, we think it is a good time to compare some of deep learning frameworks. So we compare three deep learning frameworks which can be used as a Python library. Those are Google's Tensorflow, Microsoft's CNTK, and Theano which is sort of a predecessor of the preceding two. The most common and important function of deep learning frameworks is the ability to perform automatic differentiation. Basically all the mathematical expressions of deep learning models can be represented as computational graphs, which consist of nodes and edges. Partial derivatives on each edge of a computational graph can then be obtained. With the partial derivatives, we can let software compute differentiation of any node with respect to any variable by utilizing chain rule of Calculus. First of all, the convenience of coding is in the order of CNTK, Tensorflow, and Theano. The criterion is simply based on the lengths of the codes and the learning curve and the ease of coding are not the main concern. According to the criteria, Theano was the most difficult to implement with, and CNTK and Tensorflow were somewhat easier. With Tensorflow, we need to define weight variables and biases explicitly. The reason that CNTK and Tensorflow are easier to implement with is that those frameworks provide us with more abstraction than Theano. We, however, need to mention that low-level coding is not always bad. It gives us flexibility of coding. With the low-level coding such as in Theano, we can implement and test any new deep learning models or any new search methods that we can think of. The assessment of the execution speed of each framework is that there is not meaningful difference. According to the experiment, execution speeds of Theano and Tensorflow are very similar, although the experiment was limited to a CNN model. In the case of CNTK, the experimental environment was not maintained as the same. The code written in CNTK has to be run in PC environment without GPU where codes execute as much as 50 times slower than with GPU. But we concluded that the difference of execution speed was within the range of variation caused by the different hardware setup. In this study, we compared three types of deep learning framework: Theano, Tensorflow, and CNTK. According to Wikipedia, there are 12 available deep learning frameworks. And 15 different attributes differentiate each framework. Some of the important attributes would include interface language (Python, C ++, Java, etc.) and the availability of libraries on various deep learning models such as CNN, RNN, DBN, and etc. And if a user implements a large scale deep learning model, it will also be important to support multiple GPU or multiple servers. Also, if you are learning the deep learning model, it would also be important if there are enough examples and references.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.1
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• pp.143-155
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• 2018

The Natural Landscape Rating System was introduced in the amendment of the NATURAL ENVIRONMENT CONSERVATION ACT in 2006. For landscape preservation, the system aims to consider the effects of development projects or plans implemented in a natural landscape on skylines, scenic resources, and view corridors. Currently, a lack of consistency in standards for determining Landscape Control Points (LCP) to assess landscape impact lowers the accuracy and reliability of the assessment results. As the perception of and the impact on a landscape varies, depending on the location of the LCP, it is necessary to establish a reasonable set of criteria to select viewpoints and avoid unreliability in the assessment due to unclear criteria. The intent of this study is to propose an objective and reasonable set of criteria for LCP selection to effectively measure the impact on the landscape from development projects that anticipate a change in the landscape and, ultimately, to suggest basic analysis methods to assess the landscape impact of development projects and to monitor the landscape in the future. Among the development projects affecting natural landscapes, as reported in the statement of the environmental impact assessment, cases of construction of a single building or other small-scale development projects were studied. Four spot development projects were analyzed in depth for their landscape impacts, in order to make recommendations for the LCP selection procedure, which aims to widen the scope of selection according to the direction of viewpoints from the target site. The existing results of analysis based on LCP have limitations because they failed to cover the viewshed of the target buildings when there are topographical changes in the surroundings. As a solution to this problem, a new viewshed analysis method has been proposed, with a focus on the development site and target buildings, rather than viewpoints, as used in past analysis.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.6
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• pp.407-410
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• 2018

As the operating frequency of an electromagnetic wave increases, the maximum output and wavelength of the wave decreases, so that the size of the circuit cannot be reduced. As a result, the fabrication of a circuit with high power (of the order of or greater than kW range) and terahertz wave frequency band is limited, due to the problem of circuit size, to the order of ${\mu}m$ to mm. In order to overcome these limitations, we propose a source design technique for 0.1 THz~0.3 GW level with cylindrical shape (diameter ~2.4 cm). Modeling and computational simulations were performed to optimize the design of the high-power electromagnetic sources based on Cherenkov radiation generation technology using the principle of plasma wakefield acceleration with ponderomotive force and artificial dielectrics. An effective design guideline has been proposed to facilitate the fabrication of high-power terahertz wave vacuum devices of large diameter that are less restricted in circuit size through objective verification.

• Journal of Internet Computing and Services
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• v.16 no.3
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• pp.79-93
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• 2015

With the rapid development of information technology, the ways of usage have changed drastically. The ways and efficiency of traditional service application to data processing already could not satisfy the requirements of modern users. Nowadays, users have already understood the importance of data. Therefore, the processing and saving of big data have become the main research of the Internet service company. In China, with the rise and explosion of 115 Cloud leads to other technology companies have began to join the battle of cloud services market. Although currently Chinese cloud services are still mainly dominated by cloud storage service, the series of service contents based on cloud storage service have been affirmed by users, and users willing to try these new ways of services. Thus, how to let users to keep using cloud services has become a topic that worth for exploring and researching. The academia often uses the TAM model with statistical analysis to analyze and check the attitude of users in using the system. However, the basic TAM model obviously already could not satisfy the increasing scale of system. Therefore, the appropriate expansion and adjustment to the TAM model (i. e. TAM2 or TAM3) are very necessary. This study has used the status of Chinese internet users and the related researches in other areas in order to expand and improve the TAM model by adding the brand influence, hardware environment and external environments to fulfill the purpose of this study. Based on the research model, the questionnaires were developed and online survey was conducted targeting the cloud services users of four Chinese main cities. Data were obtained from 210 respondents were used for analysis to validate the research model. The analysis results show that the external factors which are service contents, and brand influence have a positive influence to perceived usefulness and perceived ease of use. However, the external factor hardware environment only has a positive influence to the factor of perceived ease of use. Furthermore, the perceived security factor that is influenced by brand influence has a positive influence persistent intention to use. Persistent intention to use also was influenced by the perceived usefulness and persistent intention to use was influenced by the perceived ease of use. Finally, this research analyzed external variables' attributes using other perspective and tried to explain the attributes. It presents Chinese cloud service users are more interested in fundamental cloud services than extended services. In private cloud services, both of increased user size and cooperation among companies are important in the study. This study presents useful opinions for the purpose of strengthening attitude for private cloud service users can use this service persistently. Overall, it can be summarized by considering the all three external factors could make Chinese users keep using the personal could services. In addition, the results of this study can provide strong references to technology companies including cloud service provider, internet service provider, and smart phone service provider which are main clients are Chinese users.

• Journal of Intelligence and Information Systems
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• v.23 no.1
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• pp.127-141
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• 2017

Advances in Internet technologies and the proliferation of mobile devices enabled consumers to approach a wide range of goods and services, while causing an adverse effect that they have hard time reaching their congenial items even if they devote much time to searching for them. Accordingly, businesses are using the recommender systems to provide tools for consumers to find the desired items more easily. Association Rule Mining (ARM) technology is advantageous to recommender systems in that ARM provides intuitive form of a rule with interestingness measures (support, confidence, and lift) describing the relationship between items. Given an item, its relevant items can be distinguished with the help of the measures that show the strength of relationship between items. Based on the strength, the most pertinent items can be chosen among other items and exposed to a given item's web page. However, the diversity of the measures may confuse which items are more recommendable. Given two rules, for example, one rule's support and confidence may not be concurrently superior to the other rule's. Such discrepancy of the measures in distinguishing one rule's superiority from other rules may cause difficulty in selecting proper items for recommendation. In addition, in an online environment where a web page or mobile screen can provide a limited number of recommendations that attract consumer interest, the prudent selection of items to be included in the list of recommendations is very important. The exposure of items of little interest may lead consumers to ignore the recommendations. Then, such consumers will possibly not pay attention to other forms of marketing activities. Therefore, the measures should be aligned with the probability of consumer's acceptance of recommendations. For this reason, this study proposes a model-based approach to combine those measures into one unified measure that can consistently determine the ranking of recommended items. A regression model was designed to describe how well the measures (independent variables; i.e., support, confidence, and lift) explain consumer's acceptance of recommendations (dependent variables, hit rate of recommended items). The model is intuitive to understand and easy to use in that the equation consists of the commonly used measures for ARM and can be used in the estimation of hit rates. The experiment using transaction data from one of the Korea's largest online shopping malls was conducted to show that the proposed model can improve the hit rates of recommendations. From the top of the list to 13th place, recommended items in the higher rakings from the proposed model show the higher hit rates than those from the competitive model's. The result shows that the proposed model's performance is superior to the competitive model's in online recommendation environment. In a web page, consumers are provided around ten recommendations with which the proposed model outperforms. Moreover, a mobile device cannot expose many items simultaneously due to its limited screen size. Therefore, the result shows that the newly devised recommendation technique is suitable for the mobile recommender systems. While this study has been conducted to cover the cross-selling in online shopping malls that handle merchandise, the proposed method can be expected to be applied in various situations under which association rules apply. For example, this model can be applied to medical diagnostic systems that predict candidate diseases from a patient's symptoms. To increase the efficiency of the model, additional variables will need to be considered for the elaboration of the model in future studies. For example, price can be a good candidate for an explanatory variable because it has a major impact on consumer purchase decisions. If the prices of recommended items are much higher than the items in which a consumer is interested, the consumer may hesitate to accept the recommendations.

• Economic and Environmental Geology
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• v.49 no.6
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• pp.445-458
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• 2016

Most of water curtain cultivation (WCC) area in Korea has been inveterately suffering from the gradual draw-down of groundwater level and related shortage of water resources at the late stage of WCC peak time. To solve this problem, artificial recharge techniques has been recently applied to some WCC area. This study introduces infiltration gallery, which is one of the artificial recharge methods, and tentatively examined the effectiveness of three galleries installed at Sangdae-ri WCC area of Cheongju City. Seven galleries are set up at each empty space between eight vinyl houses in this area and its dimension is designed as 50 cm in each width and height and 300 cm in each length. Installation process was including bed excavation, backfill with gravels and silica sands, and completion of gallery by equipment of piezometer and covering with non-woven cloth. For each B, C, D gallery, 3 types of test including preliminary, four step and one long-term injection were performed. The first preliminary test showed the rough relations between injection rates and water level rise as follows; 20 cm and 30 cm level rise for $33.29{\sim}33.84m^3/d$ and $45.60{\sim}46.99m^3/d$ in B gallery; 0 cm, 16 cm and 33 cm level rise for $21.1m^3/d$, $33.98m^3/d$ and $41.69m^3/d$ in C gallery; 29 cm and 42 cm level rise for $48.10m^3/d$ and $52.23m^3/d$ in D gallery. Afterwards, more quantitative results estimating effectiveness of artificial recharge were reasoned out through stepped and long-term injection tests, which is expected to be employed for estimating water quantity re-injected into the aquifer through these galleries by natural injection over the period of WCC peak time.