• The Korean Journal of Quaternary Research
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• v.24 no.2
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• pp.23-34
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• 2010

The purpose of this study is to clarify the characteristics of geomorphic surfaces and investigate their geomorphological development at Sinsong-ri archaeological sites by the classification of geomorphic surfaces. The sedimentary facies of trench 1, 2 and 3 were identified and pollen analysis was performed at site 3. The geomorphic surfaces are classified by hillslope, valley plain, alluvial fan and river terrace. Most of the study area is located on low hillsides and valley plains are connected with tidal flats extended from small river valley. Also, alluvial fans are distributed over the piedmont and narrow, long river terraces are developed downstream along the Sojeong-stream flowing between valley plain and hillsides. River valleys were deeply eroded during the Last Glacial Maximum (LGM) periods, responded to the lowest sea level among the hillslopes and valley plains are formed during the Holocene. The sedimentary facies are identified composed of basal gravel layers with coarse gravels and sands, relatively thick culture layer of the Bronze Age and thin layer during the early Iron Age in upper part study area. Thus, land uses during the Bronze Age people was performed more intensively comparing to the early Iron Age by deforestation for habitation.

• Journal of the Korean association of regional geographers
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• v.17 no.5
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• pp.568-581
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• 2011

Having gone through the international financial crisis in 1997, the Korean government has sought a new future economic breakthrough. In this line, the government chose the cultural contents business and has supported this area intensively. With the cultural contents promotion policy initiated to foster the world-class culture business based on the traditional Korean culture, Andong, which has diverse cultural traditions, was rediscovered. The Andong local government and the local power elites decided that this promotion policy can not only be an opportunity to invigorate the sluggish local economy, but also help eliminate the old-fashioned image of Andong, and thus actively promoted the cultural contents business. However, there's a conflict among the local elites over which cultural tradition should be chosen as a genuine local cultural tradition. The different views and efforts regarding the cultural identity of the region by each entity not only contributed significantly to the recovery of the local economy by revitalizing tourism, but also helped the region gain an advantageous position in competition with other regions over limited resources. This progress became the groundwork for attracting major institutions and facilities, which are essential for the revitalization of the local economy.

• Journal of Sensor Science and Technology
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• v.8 no.5
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• pp.359-367
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• 1999

CsI(Li) single crystals doped with 0.02, 0.1, 0.2 and 0.3 mole% lithium as an activator were grown by Czochralski method. The lattice structure of grown CsI(Li) single crystal was bcc, its lattice constant was $4.568\;{\AA}$. The absorption edge of CsI(Li) single crystal was 245 nm, and the spectral range of luminescence was $300{\sim}600\;nm$, its maximum luminescence intensity appeared at 425 nm. The energy resolutions of CsI(Li) single crystal doped with 0.2 mole% lithium were 14.5% for $^{137}Cs$(662 keV), 11.4% for $^{54}Mn$(835 keV) and 17.7% and 7.9% for $^{22}Na$(511 keV and 1275 keV), respectively. The relation formula of $\gamma$-ray energy versus energy resolution was ln (FWHM%) = -0.893lnE + 8.456 and energy calibration formula was ${\log}E_r=1.455\;{\log}(ch.)-1.277$. The phosphorescence decay time of CsI(Li) crystal doped with 0.2 mole% lithium was 0.51 s at room temperature, and its time resolution measured by CFT(constant-fraction timing method) was 9.0 ns.

• School Mathematics
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• v.16 no.4
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• pp.709-726
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• 2014

The purpose of the study was to pay attention to the studies of P. Cobb which have actively been quoted in the international research of mathematics education for the last three decades and to look at the result and effect of his research. In particular, we in-depth studied theories and the methods of the study which he has tried to reduce the gap in the theory and practice and investigated effects of his research to the Korean societies of mathematics education. Cobb made special effort to integrate radical constructivism and social constructivism and used emergent theory and symbolic interactionism as theoretical background of the study. Also he analyzed the mathematics classroom in individual and social perspectives based on the interpretive frames of social norm, sociomathematical norm and classroom-mathematical practices then dealt with equity and identity of the students. Because Cobb contributed significantly to the development of practical theory using design experiment as the method of studies, we presented the definition, characteristics, principles, processes and practices of the design experiment. We anticipate that his ways of research would be used as means of unifying the theory and the practice in school.

• Archives of design research
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• v.18 no.3 s.61
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• pp.63-74
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• 2005

Modern society is diversified society and is under complicated situation as the boundary of each area has been disappeared. To understand and accept such complicated situation as widely as possible, it is required to understand interaction. of receiver with intertextual environmental arts as the structure of open text. This study examined interaction of environmental arts in terms of intertextual feature based on experience of receiver on combined element of different space and time, combination of genres. This is the concept of meaning personal experience or situation as receiver participates the process of completing art works, and set the fantasy, post-place and speciality of location and temporal-spatial expression method, as characteristics of intertextuality. Features of such experience elements are used as methodology of analyzing characteristics of each work. Feature of fantasy uses strategy of inducing spatial experience of receiver with dematerialization for post-place and expands the place where events occur with intervention of contingency and event situation. It suggests the spatial-temporal expression method as the features focusing on process and reflecting changes in spatial-temporal continuum and speciality of place emphasizing context of place. In conclusion, environmental arts needs to be deep rooted on complicated existence aspect of receiver beyond metaphysical dimension depending on presence and to accomplish conversion of awareness of supplying bisection of life from that place. By doing so, environmental arts can live textual life as it gets together with all other texts in terms of text dimension and creativity can be reborn as practical creativity in intertextuality rather than uniqueness. Such combination with other areas and acceptance of various aspects of receivers who see and experience this will result to creation of open works which can be create newly over and over again in multi-dimensional aspects.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.7
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• pp.15-25
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• 2003

An experimental. study is carried out to investigate the near-wake characteristics of an airfoil oscillating in pitch. An NACA 4412 airfoil is sinusoidally pitched about the quarter chord point between the angle of attack -6$^{\circ}$ and +6$^{\circ}$. A hot-wire anemometer is used to measure the phase-averaged mean velocities in the near-wake region of an oscillating airfoil. The freestream velocities of present work are 3.4, 12.4, 26.2 m/s, and the corresponding Reynolds numbers are 5.3${\times}10^4$, 1.9${\times}10^5$, 4.l${\times}10^5$, and the reduced frequency is 0.1. Streamwise velocity profiles are presented to show the Reynolds number effects on the near-wake region behind an airfoil oscillating in pitch. All the cases in these measurements show that the velocity defects by the change of the Reynolds number are very large at the lowest Reynolds number $R_N$=5.3${\times}10^4$: and are small at the other Reynolds numbers ($R_N$=1.9${\times}10^5$ and 4.l${\times}10^5$) in the near-wake region. A significant difference of phase-averaged mean velocity between 5.3${\times}10^4$, and 1.9${\times}10^5$ is observed. The present study shows that a critical value of Reynolds number in the near-wake of an oscillating airfoil exists in the range between 5.3${\times}10^4$, and 1.9${\times}10^5$.

• Journal of the Society of Disaster Information
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• v.15 no.4
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• pp.597-606
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• 2019

Purpose: This paper is for the improvement of the safety education system in the construction industry, which has become a great threat to domestic industrial safety. Among the industrial sectors, the accident rate and death rate in the construction industry are the highest, and measures for falls in the litigation work are needed. Method: The application of the Analytic Hierarchy Process(AHP) resulted in the following conclusions. Results: The management group of the construction industry was divided into a group of on-site workers. In addition, the practical education system was reviewed by analyzing differences in perceptions of safety education. The survey results of the two groups were analyzed through AHP by dividing the construction safety education system into three layers. Conclusion: The results showed that managers showed a great deal of importance, such as actual conditions for implementation related to education, while on-site workers indicated importance for items that were somewhat site-oriented compared to managers. In addition, the two groups did not place much weight on the effectiveness of AR and VR, which have been expanding into safety education recently.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.1
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• pp.25-33
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• 2016

In order to visualize point based Location-Based Social Network Services(LBSNS) data on multi-scaled tile map effectively, it is necessary to apply tile-based clustering method. Then determinating reasonable numbers and size of tiles is required. However, there is no such criteria and the numbers and size of tiles are modified based on data type and the purpose of analysis. In other words, researchers' subjectivity is always involved in this type of study. This is when Modifiable Areal Unit Problem(MAUP) occurs, that affects the results of analysis. Among LBSNS, geotagged Twitter data were chosen to find the influence of MAUP in scale effects perspective. For this purpose, the degree of spatial autocorrelation using spatial error model was altered, and change of distributions was analyzed using Morna's I. As a result, positive spatial autocorrelation showed in the original data and the spatial autocorrelation was decreased as the value of spatial autoregressive coefficient was increasing. Therefore, the intensity of the spatial autocorrelation of Twitter data was adjusted to five levels, and for each level, nine different size of grid was created. For each level and different grid sizes, Moran's I was calculated. It was found that the spatial autocorrelation was increased when the aggregation level was being increased and decreased in a certainpoint. Another tendency was found that the scale effect of MAUP was decreased when the spatial autocorrelation was high.

• Journal of KIISE:Software and Applications
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• v.29 no.1_2
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• pp.42-52
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• 2002

Information extraction(IE) is a process of recognizing and fetching particular information fragments from a document. In previous work, most IE systems generate the extraction rules called the wrappers manually, and although this manual wrapper generation may achieve more correct extraction, it reveals some problems in flexibility, extensibility, and efficiency. Some other researches that employ automatic ways of generating wrappers are also experiencing difficulties in acquiring and representing useful domain knowledge and in coping with the structural heterogeneity among different information sources, and as a result, the real-world information sources with complex document structures could not be correctly analyzed. In order to resolve these problems, this paper presents an agent-based information extraction system named XTROS that exploits the domain knowledge to learn from documents in a semi-structured information source. This system generates a wrapper for each information source automatically and performs information extraction and information integration by applying this wrapper to the corresponding source. In XTROS, both the domain knowledge and the wrapper are represented as XML-type documents. The wrapper generation algorithm first recognizes the meaning of each logical line of a sample document by using the domain knowledge, and then finds the most frequent pattern from the sequence of semantic representations of the logical lines. Eventually, the location and the structure of this pattern represented by an XML document becomes the wrapper. By testing XTROS on several real-estate information sites, we claim that it creates the correct wrappers for most Web sources and consequently facilitates effective information extraction and integration for heterogeneous and complex information sources.

• Journal of KIISE:Software and Applications
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• v.30 no.12
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• pp.1208-1219
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• 2003

The Internet has become a part of our life and has changed our living environments dramatically. However, Electronic Commerce (EC) stays currently at a level that a buyer deals only with an one-sided condition (price) proposed by a seller or compares the proposed condition to find a better one. As the agent technology makes progress, EC requires negotiation that is not one-sided but is a way to maximize profits of both seller and buyer. Moreover, negotiation in EC should consider multiple issues rather than a single issue to replace the traditional commerce. In this paper we propose a negotiation model, which guarantees balanced profits between two agents through negotiation using multi-issues, and makes a deal successfully under time-constraint environment. The proposed negotiation model suggests strategies(alternative and simultaneous strategy) that change the value of issues with each agent has time for negotiation. In this paper, we also suggest a strategy that proposes an offer to each other. We compare the proposed negotiation model with another negotiation model. The experimental results show that dynamic conceder tactic and linear tactic showed balanced profits and a high percentage of deals for negotiation between two agents, and the sum of utilities of two agents is high, when the alternative strategy is used.