• Journal of the Korean earth science society
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• v.30 no.6
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• pp.734-743
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• 2009

In order to examine how climatological condition can influence on urban scale particulate air pollutants, single and cross spectrum analysis have been performed to daily mean concentrations of particulate matters ($PM_{10}$) in Busan together with the climatological variables over the Asian dust source regions. Single power spectrum analysis of $PM_{10}$ concentrations in Busan shows that, aside from the typical and well-known periodicities, 3-4 year of peak periodicity of power spectrum density was identified. In cross spectrum analysis, this 3-4 year periodicity is found to have a strong positive correlation with the wind speed and pressure, and negative with the temperature and relative humidity, which is rather consistent with both characteristics of air mass during the Asian dust event whose periodicities have been recorded inter-annually over the Korean urban cities. Over the Asian dust source regions, $PM_{10}$ vs. precipitation shows no significant periodicity from the time series of precipitation data, but the periodicity of EDI (Effective Drought Index) shows some interannual variabilities ranging from 2 to 4 years over the various source regions, suggesting that, rather than precipitation itself, the EDI could be more closely associated with the occurrence frequency of Asian dust and interannual variability of urban particle concentrations in Korean cities.

• Economic and Environmental Geology
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• v.51 no.3
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• pp.233-248
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• 2018

Strata of the Central sub-basin in the Gunsan Basin, offshore, western Korea were analyzed by using integrated stratigraphy approach. As a result, five distinct unconformity-bounded units are recognized in the basin: Sequence I (Cretaceous or older(?)), Sequence II (Late Cretaceous), Sequence III (late Late Cretaceous or younger(?)), Sequence IV (Early Miocene or older(?)), Sequence V (Middle Miocene). Since the late Late Jurassic, along the Tan-Lu fault system wrench faults were developed and caused a series of small-scale strike-slip extensional basins. The sinistral movement of wrench faults continued until the Late Cretaceous forming a large-scale pull-apart basin. However, in the Early Tertiary, the orogenic event, called the Himalayan Orogeny, caused basin to be modified. From Late Eocene to Early Miocene, tectonic inversion accompanied by NW strike folds occurred in the East China. Therefore, the late Eocene to Oligocene was the main period of severe tectonic modification of the basin and Oligocene formation is hiatus. The rate of tectonic movements in Gunsan Basin slowed considerably. In that case, thermal subsidence up to the present has maintained with marine transgressions, which enable this area to change into the land part of the present basin.

• Journal of The Korean Association For Science Education
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• v.34 no.6
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• pp.559-569
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• 2014

In this case study, we investigated teaching strategies of science teacher's teaching in science museum. Two secondary science teachers who completed a teacher training course on teaching in science museums participated in this study. We conducted interviews about their perceptions on teaching in science museum and their teaching plans before teaching. Then, we observed and recorded their teaching practices in the science museum throughout one semester, and collected all of the teaching materials. The interviews were also conducted after every lessons and at the end of the semester. For the analysis of teaching strategies, we used a framework that was revised from the framework for museum practice (FMP). The analysis of results revealed that the teachers understood the significance of planning the activities in a series of pre-visit, during-visit, and post-visit, so that they structured their teaching as continuous activities, not as an one-time event. However, they showed differences in the extent of connecting the activities with the national science curriculum according to their teaching objectives. In addition, there were differences in strategies such as promoting social interaction, evoking students' curiosity and interest, providing students with choices and control, and inducing engagement and challenge depending on each teacher's perceptions and experiences on teaching in science museum. These results suggest that science teacher education for the professional development of teaching in science museum should systematically provide knowledge and experiences on teaching strategies based on appropriate perceptions on teaching in science museum.

• The Korean Journal of Archival Studies
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• no.53
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• pp.45-77
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• 2017

This study intends to rehabilitate the memories of the social other which have been gradually forgotten in the social events overloaded with the undemocratic violence in South Korea today. This study explores a case of Yongsan Tragedy in 2009 among the most tragic events. It notes the autonomous ways in which activist artists would like to memorize the socio-historical events anew despite the emptiness of public records. In other words, this study considers the Yongsan case to be significant that a group of the public, artists, grassroots activists, religion men got together in solidarity so as to create the contested narratives countering dominant memories and thus to signify the records written by the civil society. Among others, activist artists had documented the unofficial counter-memories of socially alienated peoples in terms of planning a series of artistic events such as opening some gallery exhibitions and performance events, issuing a volume of work books, comics and photographies, online broadcasting, and directing some documentaries. Especially, this paper tends to note the documentation of on-site activist artists to record the counter-memories against social oblivion. By doing so, it finally suggests how we could document the Yongsan Tragedy both to search out the archival implications of today's art activism and to insert those artistic records into the commonly shared counter-memories in a more inclusive way.

• East European & Balkan Studies
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• v.32
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• pp.257-281
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• 2012

Are the policies and strategies which weak and small states choose to follow for ensuring their's own security meaningless? Can the fate of weak states be guaranteed only by the neighboring benign strong states and be in certain international relations favoring for them? In this paper, to answer these questions, what kinds of security policies and foreign policies had small states chosen which were in the face of threats of great powers will be examined. Between the two world war, the series of event which took place in central and eastern European countries(CEEc) have been selected to examine the hypothesis and theories of international relations and foreign policies, and at the same time cited as examples of failed foreign policy and security strategy. During interwar periods, CEEc were the prime examples for examining what kind of policies and strategies had the small states chosen over the international relations in which the smalls had to struggle to survive between neighbouring the powers and between the hostiles. Furthermore, for the measures which the smalls had chosen had no effect when the great power threatened military to them, the main purpose of this paper is to examine what was the best choose to depend their survival. For this purpose, in this paper, several strategies which the smalls can choose and the counterfactuals, that is "if the smalls chosen another strategies, they could...", will be examined.

• Journal of Satellite, Information and Communications
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• v.1 no.2
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• pp.95-100
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• 2006

The COMS(Communication, Ocean and Meteorological Satellite) EPS(Electrical Power Subsystem) is derived from an enhanced Eurostar 3000 version. Eurostar 3000 EpS is fully autonomous operation in nominal conditions or in the event of a failure and provides a high level of reconfigure capability. This paper introduces the COMS EPS preliminary design result. COMS EPS consists of a battery, a solar arrat wing, a PSR(Power Supply Regulator), a PRU(Pyrotechnic Unit), a SDAM(Solar Array Drive Mechanism) and relay and fuse brackets. COMS EPS can offer a bus power capability of 3 kW. The solar array is made of a deployable wing with two panels. One type fo solar cells is selected ad GaAs/Ge triple junction cells. Li-ion battery is base lined with ten series cell module of five cells in parallel. PSR associated to battery and solar array wing generates a power bus fully regulated at 50 V. Power bus os centralized protection and distribution by relay and fuse brackets. PRU provides power for firing actuarors devices. The solar array wing is rotated by the SADM under control of the attitude orbit control subsystem. The control and monitoring of the EPS, especially of the battery, is performed by the PSR in combination with the on-board software.

• Journal of Chest Surgery
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• v.43 no.3
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• pp.246-253
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• 2010

Background: Our objective was to review the long-term prognosis of patients with preoperative mild to moderate ischemic mitral regurgitation who underwent off-pump coronary artery bypass grafting. Material and Method: We prospectively followed 1,000 consecutive and systematic off-pump coronary artery bypass grafting patients who were operated on between September 1996 and March 2004; follow-up was achieved for 97%. Sixty-seven patients (6.7%) had mild to moderate ischemic mitral regurgitation at the time of surgery. Operative mortality, actuarial survival and major adverse cardiac event free survival were compared to assess the effect of ischemic mitral regurgitation. Result: Average follow-up was $66{\pm}22$ months. Patients with ischemic mitral regurgitation were older (p<0.001), had lower ejection fractions (p<0.001) and more comorbidities. Significantly more female patients presented with ischemic mitral regurgitation (p=0.002). There was no significant difference in operative mortality and perioperative myocardial infarction in ischemic mitral regurgitation patients (p=0.25). Eight-year survival was decreased in ischemic mitral regurgitation patients ($39.6{\pm}11.8%$ vs $76.7{\pm}2.2$, p<0.001). However, after correcting for risk factors, mild to moderate ischemic mitral regurgitation was not found to be a significant independent risk factor for long-term mortality (p=0.42). Major adverse cardiac event free survival at 8 years was significantly lower in ischemic mitral regurgitation patients ($53.12{\pm}12%$ vs $77{\pm}2%$, p<0.001). After correction for risk factors, ischemic mitral regurgitation remained a significant independent cause of major adverse cardiac events (HR: 2.31), especially congestive heart failure and recurrent myocardial infarction. Conclusion: In our series, patients with preoperative mild to moderate ischemic mitral regurgitation had a higher prevalence of preoperative risk factors than patients without ischemic mitral regurgitation. They had comparable perioperative mortality and morbidity, but, in the long term, were found to be at elevated risk for recurrent cardiac events.

• Korean Security Journal
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• no.35
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• pp.7-36
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• 2013

Collecting international terrorism database is a challenging task not only for criminal justice personnel but also for criminologists in comparison to the case of common types of crime database. Yet, there has been growing interests and efforts in establishing a comprehensive terrorist events data base in the world. This current study has a goal to introduce an example world terrorism database case developed by START center in the United States. The START center developed the Global Terrorism Database (GTD) on the basis of by the Pinkerton Global Intelligence Service data (PGIS) originally collected by the Pinkerton. Furthermore, The START expended the GTD by collecting data from open source terrorist event data via internet and other resources. In this study, specifically, it describes the development and the nature of the GTD in general and the data collection efforts made by the STATA until today. Finally, this study provides a sketchy of the nature of the GTD data by showing the descriptive statistical analyses and time-series analyses result illustrating distribution of the world terrorism events. The limitation, policy implications and contribution of this study discussed in this paper.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.446-452
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• 2020

As the use of children's school buses increases, accidents caused by the negligence of school bus drivers and ride carers have also increased significantly. To prevent such accidents, the government is coming up with various policies. We propose an accident prevention and safety management system for children's school buses. Through this system, bus drivers can easily check whether each child is seated and whether the seat belt is used, so it is possible to quickly respond to children's conditions while driving. With the ability to recognize faces by analyzing camera images, children can use a seat belt that is automatically adjusted to their height. It is therefore possible to prevent secondary injuries that may occur in the event of a traffic accident. In addition, a sleeping child-check system is provided to confirm that all children get off the bus, and a text service is provided to inform parents of their children's locations in real time. Based on Raspberry Pi, the system is implemented with cameras, pressure sensors, motors, Bluetooth modules, and so on. This proposed system was attached to a bus model to confirm that the series of functions work correctly.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.809-818
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• 2018

In this paper, in order to evaluate the impact of future climate change in North Korea, we collected the climate data of each station in North Korea provided by WMO and expanded the lack of time series data. Using the RCP climate change scenario, And the impact of climate change on disasters using local vulnerability to disasters in the event of a disaster. In order to evaluate this, the 11 cities in North Korea were evaluated for Design Rainfall Load, human risk index (HRI), and disaster impact index (DII) at each stage. As a result, Jaffe increased from C grade to B grade in the Future 1 period. At Future 2, North Hwanghae proved to be dangerous as it was, and Gangwon-do and Hwanghae-do provincial grade rose to C grade. In the case of Future 3, Pyongyang City dropped from C grade to D grade, Hamgyong and Gyeongsang City descend from B grade to C grade, Gangwon-do and Jagangdo descend from C grade to D grade and Pyongyang city descend from C grade to D grade. Respectively.