• Journal of Environmental Science International
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• v.22 no.9
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• pp.1199-1211
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• 2013

Mobile sources produce a significant fraction of total anthropogenic emissions in Korea and have harmful effects on air quality. Mobile emissions are intrinsically difficult to estimate due to complicated road networks and variations of traffic volume with location and time. To measure traffic pollutants with high temporal and spatial resolution under real conditions a mobile laboratory was designed. The mobile laboratory provide concentrations of $SO_2$, CO, NO, $NO_2$ and location coordinate value. This approach allowed for pollutant level measurements on many roads within short periods of time. In this study, on-road concentrations of $SO_2$, CO, NO and $NO_2$ were measured using mobile platform measurement along the 25 main roads in Busan to estimate the average air pollution level in short time difference. The measurements were conducted on favorable meteorological days from 2010 to 2012 and the overall concentrations of $SO_2$, CO, NO and $NO_2$ were 0.006, 0.8, 0.182 and 0.055 ppm respectively. The result showed that the concentration of CO, NO and $NO_2$ on road were twice, 18 times and 2.5 times higher than regional air quality monitoring sites mean in same period.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.4
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• pp.506-510
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• 2007

Digital Magnetic Compass(DMC) has a robust feature against interference in the indoor environment better than compass which is easily disturbed by electromagnetic sources or large ferromagnetic structures. Ultrasonic Sensors are cheap and can give relatively accurate range readings. So they ate used in Simultaneous Localization and Mapping(SLAM). In this paper, we study the Simultaneous Localization and Mapping(SLAM) of mobile robot in the indoor environment with Digital Magnetic Compass and Ultrasonic Sensors. Autonomous mobile robot is aware of robot's moving direction and position by the restricted data. Also robot must localize as quickly as possible. And in the moving of the mobile robot, the mobile robot must acquire a map of its environment. As application for the Simultaneous Localization and Mapping(SLAM) on the autonomous mobile robot system, robot can find the localization and the mapping and can solve the Kid Napping situation for itself. Especially, in the Kid Napping situation, autonomous mobile robot use Ultrasonic sensors and Digital Magnetic Compass(DMC)'s data for moving. The robot is aware of accurate location By using Digital Magnetic Compass(DMC).

• Journal of the Korea Institute of Information Security & Cryptology
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• v.12 no.3
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• pp.49-59
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• 2002

As the electronic commerce increases rapidly in the mobile communication, security issues become more important. A suitable authentication and key agreement for the mobile communication environment is a essential condition. Some protocols based on the public key cryptosystem such as Diffie-Hellman, EIGamal etc. were adapted in the mobile communication. But these protocols that are based on the difficult mathematical problem in the algebra, are so slow and have long key-length. Therefore, these have many limitation to apply to the mobile communication. In this paper, we propose an authentication and key agreement protocol based on NTRU to overcome the restriction of the mobile communication environment such as limited sources. low computational fewer, and narrow bandwidth. The proposed protocol is faster than other protocols based on ECC, because of addition and shift operation with small numbers in the truncated polynomial ring. And it is as secure as other existent mathematical problem because it is based on finding the Shortest or Closest Vector Problem(SVP/CVP).

• Journal of Korea Trade
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• v.27 no.1
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• pp.192-210
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• 2023

Purpose - Vietnam has the fastest growing digital economy in Southeast Asia and is emerging as a critical overseas market for Korean banks in the post-COVID-19 era. Accordingly, many Korean banks entered the Vietnamese market to overcome the limitations of the saturated domestic financial market and create new revenue sources. This study examined the current status of digital finance in Vietnam and the cases of Korean banks that have succeeded in the Vietnamese market. Then, importance-performance analysis (IPA) was conducted on local customers, managers and staff members of Korean banks in Vietnam. Design/methodology - In this study, we analyzed the importance and satisfaction factors of mobile banking app usage in Vietnam through IPA. In particular, we identified the differences between the two groups by considering the viewpoint of customers who use mobile banking apps and that of managers and staff members who provide mobile banking services. Findings - The IPA results from the customer group and managers and staff members group were generally similar, but differences were observed in Ease of Use (Technology), Innovativeness (Organization), and Increase in Revenue (Economic). In the case of the customer group, Ease of Use (Technology) is located in the second quadrant, which shows low satisfaction compared to high importance. However, in the managers and staff members group, Ease of Use (Technology) is located in the first quadrant, which indicates high importance and high satisfaction. This difference in perception can cause complaints from local customers; thus, it is necessary to change the perception of the technological aspect for ease of use of mobile banking apps in consideration of the customer's position. In addition, it is necessary to allocate the resources invested in the Innovativeness (Organization) and Increase in Revenue (Economic) to Ease of Use (Technology). Originality/value - In this study, based on the HOTE framework, factors for using mobile banking apps were derived, and IPA was conducted targeting local customers (app user) and managers and staff members (app provider) of Korean banks in Vietnam. Through this, we presented the results of empirical analysis that can help Korean banks efficiently utilize limited resources and budgets.

• Journal of environmental and Sanitary engineering
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• v.7 no.2
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• pp.69-82
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• 1992

Air pollution in urban areas of Korea is considered in significantly serious level because of population exceeding the capacity and diversified facilities for the activities in socioeconomic field, education, politics and even cultural society in confined areas. Korea is one of the most populated countries and the largest five cities occupy 2.4% of total area but 45% of total population. Patterns of urban air pollution are also changing due to the change of emission sources and fuel usage. Essential recovery of urban environment in Korea has become extremely difficult and necessitates enormous investment. Accurate understanding of problems should be pursued for the efficient and effective improvement of the environment. In this article, air pollution phenomena in urban areas are analyzed mainly with respect to recent urban air pollution trend and pollution sources and possible control strategies are discussed : 1) source control-stationary and mobile, 2) air quality management strategies, 3) research and development.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.467-472
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• 2003

Of those off-road diesel engines, the railroad diesel rolling stocks (RDRS) for passenger and freight transportation become a growing issue since they are emitting enormous amounts of various air pollutants. Furthermore, up to the present time, emissions from these sources are not well controlled. One of main purposes in this study is to develop emission factors for the RDRS and to estimate a total amount of major air pollutants from the RDRS in Korea. Prior to develop a Korean mode emission factor, the emission factor from the USEPA was simply applied for comparative studies. As a conclusion, based on the emissions calculated from both the USEPA mode and the KoRail mode, the RDRS is considered as one of significant mobile sources of major air pollutants including NOx and CO, and thus management plans and control strategies for the RDRS must be established to improve air quality near. future in Korea.

• Journal of Environmental Science International
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• v.26 no.9
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• pp.1045-1055
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• 2017

Characterization of spatio-temporal variations in $PM_{2.5}$ in Gyeongnam (GN) province during 2015-2016 was investigated to assess the air quality in this area in terms of fine particles. Yearly mean concentrations of $PM_{2.5}$ ranged from 19.1 to $29.5{\mu}gm^{-3}$. High concentrations of $PM_{2.5}$ were observed in spring ($21.2-30.3{\mu}gm^{-3}$) and winter ($20.2-30.3{\mu}gm^{-3}$). Low concentrations of $PM_{2.5}$ were generally observed in fall ($16.2-23.2{\mu}gm^{-3}$). $PM_{2.5}$ concentration was highest in the morning (10 AM). The fractions of $PM_{2.5}$ in $PM_{10}$ were 0.51-0.62 and two were significantly correlated (r=0.779-0.830), suggesting common sources (fossil fuel combustion, mobile sources, etc). CO was significantly correlated with $PM_{2.5}$ in highly urbanized areas such as the city of Changwon (CW, r=0.711), compared to other air pollutants ($SO_2$, $NO_2$, and $O_3$), suggesting dominance of industrial combustion sources.

• The Korean Journal of Emergency Medical Services
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• v.23 no.3
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• pp.41-51
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• 2019

Purpose: This dissertation is a descriptive research study analyzing the accuracy and reliability of the cardiopulmonary resuscitation (CPR) application developed in Korea. Methods: Two faculty members from the emergency medical services department and the emergency medicine department searched applications from July 1 to July 10, 2019 and selected a total of 13 applications. Twelve questions were assessed for information accuracy and three were assessed for reliability. In accordance with application types, the number and mean ± standard deviation were analyzed. The t-test was used to compare the accuracy of CPR information in accordance with information sources. Results: The results revealed the following errors: 7 cases (53.8%) identified the chest center lining from the nipple center-line as the chest pressure point; 5 cases (38.5%) did not provide information on the depth of 6 cm that should not be exceeded; and 4 cases (30.8%) did not provide advise to check respiration. When the CPR information sources were included, the information accuracy score was high; a significant difference was observed (p=.035). Conclusion: In the case of applications providing medical information regarding CPR, it is necessary to provide at least authoritarian, sources of information, and author transparency as well as continuous effort and attention.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.8
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• pp.623-631
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• 2013

Wireless LAN (WLAN) interface is one of the major sources drastically depleting the battery power of mobile devices such as smartphones and tablets. Most commercial mobile devices employ a power saving technique putting their WLAN interface into a sleep state when there is no network traffic, and thereby, save the battery power. However, since an access point (AP) just transmits the packet(s) received from a server to the corresponding mobile device immediately, it may cause a problem that the mobile device constantly remains in an awake state so that its battery power is rapidly drained. In this paper, we point out this problem and propose a new scheme that can save the mobile device's battery power with an adaptive packet scheduling at the AP side. From the experimental results based on a testbed, we found that the proposed scheme outperforms existing schemes over 50% in terms of power saving.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2418-2423
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• 2012

A smart phone which is one of the new IT technologies can be viable on various enterprise applications since it provides easily information and services. Especially, a smart phone can request queries to a server which finds massive data for decision making and receive the results of the queries from the server. However, a smart phone has a drawback that its battery is consumed easily due to the 4G communication. In this paper, we propose mobile views in order to reduce the easy consumption of a battery on mobile client-server environment. The proposed mobile view scheme reduces the number of communication which is leading to power consumption using materialized views for processing queries. We also classify the methods to control the consistency of the mobile view as the sources of the view are changed and present the cost of each method based on the cost model of battery consumption.