• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.902-909
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• 2023

This study evaluated the performance test of a small-sized LTE-Maritime(LTE-M) transceiver that was developed and promoted to expand the use of intelligent maritime traf ic information services led by the Ministry of Oceans and Fisheries with the aim of supporting the prevention of maritime accidents. Accoriding to statistics, approximately 30% of all marine accidents in Korean water occur with ships weighing less than 3 tons. Therefore, the blind spots of maritime safety must be supplemented through the development of small-sized transceivers. The small transceiver may be used in fishing boats that are active near coastal waters and in water leisure equipment near the coastline. Therefore, verifying whether sufficient performance and stable communication quality are provided is necessary, considering the environment of their real usage. In this study, we reviewed the communication quality goals of the LTE-M network and the performance requirements of small-sized transceivers suggested by the Ministry of Oceans and Fisheries, and proposed a test plan to appropriately evaluate the performance of small-sized transceivers. The validity of the proposed test method was verified for six real-sea areas with a high frequency of marine accidents. Consequently, the downlink and uplink transmission speeds of the small-sized LTE-M transceiver showed performances of 9 Mbps or more and 3 Mbps or more, respectively. In addition, using the coverage analysis system, coverage of more than 95% and 100% were confirmed in the intensive management zone (0-30 km) and interesting zone (30-50 km), respectively. The performance evaluation method and test results proposed in this paper are expected to be used as reference materials for verifying the performance of transceivers, contributing to the spread of government-promoted e-navigation services and small-sized transceivers.

• Management & Information Systems Review
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• v.33 no.2
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• pp.101-118
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• 2014

In the mid-2000s, Web 2.0 appears and is becoming a general cultural code with the keyword of participation, sharing, and openness. Web 2.0, in which consumption is being transformed by the participatory web culture, has evolved. However, associated with the evolution of Web 2.0, several significant concerns appears in a society. Among them, this study will focuses on the cyber-ethics issues. There are limitations to solve the cyber-ethics problems only in the technical and legal approaches. Therefore, the current article intends to consider comprehensively the antecedents of cyber-ethics such as individual characteristics, social influence, and cultural characteristics. Specifically, (1) Do individual characteristics(i.e., self-efficacy, locus of control) affect cyber-ethics in the Web 2.0 environment?, (2) Do social influence(i.e., subjective norm) have an effect on cyber-ethics?, (3) Do cyber -ethics have an impact on user participation in the Web 2.0 services(i.e., retrieval and creation)?, finally (4) Do international cultural difference have a moderation effect on the relationship between cyber-ethics and user participation? For testing empirically the hypothesized research model, this study collected questionnaires in South Korea as well as U.S.A. The results showed that individual characteristics and social influence affect cyber-ethics toward user's creative activities in Web 2.0 sites.

• Journal of The Korean Association For Science Education
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• v.36 no.1
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• pp.29-43
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• 2016

There have been much efforts to reconstruct the science curriculum focusing on Disciplinary Core Ideas(DCI) in many countries such as America and Europe, the most practical effort has been to design a curriculum with learning progressions(LPs). LPs describe stepwise how students can systematically move toward the understanding of more sophisticated ideas or scientific activities and explain in succession the process of understanding the ideas while the students learn. In this study, a LP for ecosystems has been developed, and the developed LP is then evaluated accordingly. The Ecosystem is one of the DCI of the life science in Next Generation Science Standards(NGSS). The development process of the LP was set at step 4(Development, Assessment, Analysis, and Amendment), and developed through an iterative process of sequences. As a result of analyzing the developed LP, an assessment based on the LP provides reliable information to identifying student ability. This study proposes the development process of the LP and its methodological aspects to use Core Achievement Standards, Ordered Multiple-Choice items and the Rasch model. In addition, using the empirically proven LP suggests a way of strengthening curriculum linked to educational content, teaching methods and assessment. Utilizing the proposed development process in this study will be to present the standard into the direction of becoming part of the curriculum. Currently, the state of domestic research for the LP is still lacking. This study determined the development process of the LP and the need to conduct future research on the LPs.

• Journal of the Korean earth science society
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• v.41 no.2
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• pp.111-128
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• 2020

This study presents a possibility of intensification of fine dust mass concentration due to the complex urban structure using data mining technique and clustering analysis. The data mining technique showed no significant correlation between fine dust concentration and regional-use public urban data over Seoul. However, clustering analysis based on nationwide-use public data showed that building heights (floors) have a strong correlation particularly with PM₁₀. The modeling analyses using the single canopy model and the micro-atmospheric modeling program (ENVI-Met. 4) conducted that the controlled atmospheric convection in urban area leaded to the congested flow pattern depending on the building along the distribution and height. The complex structure of urban building controls convective activity resulted in stagnation condition and fine dust increase near the surface. Consequently, the residual effect through the changes in the thermal environment caused by the shape and structure of the urban buildings must be considered in the fine dust distribution. It is notable that the atmospheric congestion may be misidentified as an important implications for providing information about the residual probability of fine dust mass concentration in the complex urban area.

• Journal of the Economic Geographical Society of Korea
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• v.20 no.1
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• pp.34-48
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• 2017

The purpose of this study is to investigate the growth of major industries and effects of regional employment on the economic growth of Goyang city and Seongnam city in Gyeonggi Province. We examine the structural changes of the industrial specialization and factors of the growth in two regions by applying Location Quotients and dynamic shift-share analysis respectively. Both regions have been strengthened gradually in their industrial bases during the last 20 years since they have developed as the bed-towns for Seoul with the First Newtown Project of the Metropolitan Seoul area. These two regions have secured in the industrial specialization and competitiveness compare to other regions in the Metropolitan Seoul area. In particular, knowledge service industries have been agglomerated in both regions. Goyang city have secured in the medical welfare, culture and tourism of service sectors, while Seongnam city have secured in the information service and science technology service sectors. Therefore, each region might be differentiated regional foster industries in these sectors in order to succeed the economic development.

• Informatization Policy
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• v.18 no.2
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• pp.3-22
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• 2011

The study of online social movements is basically concerned about the impact of the Internet on the existing social movements. More specifically, researchers have paid attention to changes in participants, leadership style and movement strategies caused by the Internet. Due to the Internet, networks of the individuals who are geographically scattered or a network of networks have emerged as new movement agents. Researchers have also analyzed a repertoire of collective action adopted by the online social movements. The increase in online social movements calls for a new interpretation of the existing social movement theories such as resource mobilization, collective identity and political opportunity structure. There are still a lot of debate about the impact of the internet on social movement and the resulting changes. Not only the early debate of cyber-optimism and cyber-scepticism, many studies done by the mid-range perspective also suggested different arguments on the impact of the Internet. This discrepancy comes from a relatively short history of online social movement study, which leads to a limited number of case studies and a shortage of date accumulations. In the future, researchers need to place more attention on the unique characteristics of different technologies and comparative studies of online social movements. The study should also extend its focus to a wide range of political systems in order to explain the impact of online social movements on political intermediary organizations and the democracy itself.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.193-193
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• 2011

본 연구에서는 산불발생인자들에 대한 정보를 각각의 요인별로 집적화하고 체계화시킴으로써 산불예방활동의 기초자료로 활용할 뿐만 아니라 산불발생 시, 산불의 거동을 예측하기 위한 자료로 활용하고자 하였다. 발생인자는 크게 연료 및 기상조건 관련 인자와 열적특성 관련 인자로 분류하고 연료 및 기상조건 관련 인자는 수종별, 부위별, 지역별, 고도별, 월별 산림연료들의 구성 요인들에 대해서 분석하였다. 수종별로는 생강나무, 초피나무, 조록싸리, 산초, 개암, 청미래, 고추나무, 철쭉, 조릿대, 털진달래 등 관목류 10개 수종과 김의털, 방아풀, 주름조개풀, 칡, 엉겅퀴 등 초본류 5개 수종 그리고 소나무, 잣나무, 리기다소나무, 해송, 구상나무, 주목 등 6개의 침엽수 및 굴참나무, 떡갈나무, 신갈나무, 갈참나무, 졸참나무, 상수리, 산개벚나무, 고채목, 개서어나무, 굴거리나무, 서어나무, 산벚나무, 때죽나무, 당단풍나무, 단풍나무 등 15개의 활엽수로 구성된 교목류를 대상으로 분석하였다. 부위별로는 생엽, 낙엽, 가지, 수피, 솔방울 등으로 구분하여 분석을 수행했으며, 지역별 구성은 강원(삼척/태백산), 경북(응봉산), 경기(용문산), 충북(월악산), 충남(계룡산), 전북(덕유산), 전남(월출산), 부산(금정산), 제주(한라산) 등 9개 지역을 대상으로 선정하였다. 고도별로는 강원도에 소재하고 있는 태백산을 중심으로 소나무와 신갈나무 생엽을 대상으로 900m, 1000m, 1100m, 1200m, 1300m, 1400m, 1500m 고도를 선정하여 분석을 수행하였다. 월별 분석데이터는 소나무 생엽의 경우, 2008년 6월부터 2010년 11월까지 매월 분석을 수행하였으며, 굴참나무 생엽의 경우에는 2008년부터 2010년까지 매년 6월부터 10월까지 생엽을 채취할 수 있는 기간 동안 분석을 수행하였다. 또한, 열적특성 관련 인자로는 착화특성(무염착화온도, 발염착화시간, 소염시간, 화염지속시간), 발열특성(총열방출량, 평균열방출률), 발연특성(총연기방출량, 최대연기밀도, 최대밀도시간) 등을 고찰하였다. 이와 같은 결과들은 산불발생인자 DB구축으로 부터 산불발생 위험도 및 동태예측의 기본 자료로 활용할 수 있을 뿐만 아니라 지역별 연료별 산림연료의 열적특성 DB로 부터 산불발생시 산불 위험도에 대한 기술정립과 응용성을 향상시킬 수 있을 것으로 사료된다. 이외에도 산림연료 종류별 열적특성을 결과를 토대로 문화재보존지역과 같이 문화적 가치가 높은 시설이나 주유소, 가스 충전소 등의 위험 시설에 대한 효과적인 보호를 위한 대처 방안을 사전에 준비할 수 있어 산불 피해에 대한 국민의 불안감을 줄일 수 있을 것으로 생각된다.

• Journal of Astronomy and Space Sciences
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• v.21 no.4
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• pp.429-440
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• 2004

Recently, real time data acquisition become important for space weather forecast and research. In this work, we have developed the data acquisition tools and their applications for space weather monitoring. We have developed programs to download the space weather data using IDL as well as programs to interactively display the image and data using ION (IDL on the Net). By using these tools, we have constructed the mirror site of Active Region Monitor (ARM) which summarizes several different solar activities, and developed ION programs to display TEC(Total Electron Contents) maps from GPS data at the passage of Korean satellites. At present, the KAO ARM mirror site (http://sun.kao.re.kr/arm) is successfully updated in every thirty minutes. The TEC maps from GPS data are expected to be used for monitoring the space environment of Korean satellites.

• Journal of the Korean association of regional geographers
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• v.10 no.2
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• pp.407-427
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• 2004

The rapid innovation of information and communication technology and its sharp falling prices have brought about the expansion of the Internet, integrating the world as one space under converged space and time. This rapid expansion of the Internet and its application in the economy have spurred the emergence of the digital economy. The Internet has influenced strongly on the changes of not only economic activities but also political, social and cultural activities. In this context, a rapidly increasing Internet expansion renders the rhetoric about the death of distance and about the meaningless of geographical place. However, the development and expansion of Internet induces a growing digital divide among nations and also a spatial inequality in a nation as the supply of the Internet has concentrated towards demand-affluent large cities. A large gap of digital access has been occurred between high income and low income countries according to a measurement of the international digital access index. In a national level, the Internet backbone has been built around large cities which favor a large amount of the Internet demand, and the affordable accessibility of these cities for the Internet services has influenced strongly on the agglomeration of Internet related industries, further inducing the construction and investment of the Internet backbone into large cities as cumulative causation effects. As a result, the expansion of the Internet affects immensely on the changes of spatial structure in a nation resulting in the new spatial phenomena such as centralization, concentration and splintering in the digitalized space-economy.

• Journal of the Korean association of regional geographers
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• v.10 no.1
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• pp.192-205
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• 2004

The purpose of this paper is to analyze the factors, which have influence upon changes of hydrological environment in time series, and evaluate water balance changes caused by urbanization. The results of the analysis and evaluation are as follow: At first, the river runoff at Gwangju River Basin keep base flow of river by storage capacity recharged in June to September and show peak in August and minimum flow in May. The groundwater recharge by urbanization accounted for 46.1% of rainfall at early-urban stage, and decreased to 36.5% and 29.9% in the 1960's and the 1990's respectively, and is likely to decrease to 27.8% in the 2010's. On the other hand, the overland flow was 9.6% of rainfall in the 1960's and 16.2% in the 1990's, and is likely to increase to 18.3% in the 2010's. When such a phenomenon is kept continuously, distorted water balance shall be worsened to create not only frequent occurrence of urban flood but also decreased base flow of Gwangju River to accelerate dry stream phenomenon. The time series study on urban redevelopment and environment maintenance describes distorted phenomenon to supply the information for nature-friendly land use, and examines relations between human activities and natural environment.