• Convergence Security Journal
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• v.6 no.1
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• pp.45-53
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• 2006

It has been proposed that several RFID authentication protocols based on hash chain. Status based authentication protocol and challenge-response based authentication protocol are secured against location tracking attacks, spoofing attacks, replay attacks, traffic analysis attacks but are vulnerable to Dos attacks. RFID authentication protocol with strong resistance against traceability and denial of service attack is secured against location tracking attack, spoofing attacks, replay attacks, DoS attacks but are vulnerable to traffic analysis attacks. The present study suggests a more secure and lightweight RFID authentication protocol which is combining the advantages of hash-chain authentication protocol and RFID authentication protocol with strong resistance against traceability and denial of service attack. The results of the secure analysts for a proposed protocol are illustrated that it is secured against location tracking attacks, spoofing attacks, replay attacks, traffic analysis attacks, Dos attacks and is a lightweight operation between server and tag.

• The Journal of the Korea Contents Association
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• v.9 no.10
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• pp.258-267
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• 2009

This study purposed to develop GIS model for evaluating hospital location in a metropolitan city. Secondly, the suitability score of hospital was compared with the number of outpatient/inpatients of hospitals. This study used administrative data collected from the annual report of the 5 ward offices from Daejeon in Korea in 2004. 7 Acute care hospitals operated in Daejeon in 2004 were selected for the analysis. The suitability of hospitals in a metropolitan city was evaluated by the economic factors which were assumed to influence the health care demand. Each criterion was measured from each Dong. Correlation coefficients between the suitability score of hospital and the number of patients were varied depending on the buffering size. The relationship showed positive relationship with the number of inpatient (0.15) and outpatients (0.10) on the 0.5km buffering size. However, the correlation coefficients were changed to a negative direction or decreased when the buffering size was increased to 1.0km, 1.5km, and 2.0km.

• Spatial Information Research
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• v.19 no.5
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• pp.75-86
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• 2011

Three-dimensional modeling of cities in the real-world is an essential task for city planning and decision-making. And many three-dimensional city models are being developed with the development of wireless Internet and location-based services that identify the location of users and provide the information increases for consumers. Especially, in case of urban areas of Korea, indoor space modeling as well as outdoor is needed due to the high-rise buildings densities. Also location-based services should be provided through spatial analysis such as the shortest path based on a space model. Many studies of three-dimensional city models are feature models. In a feature model, space is represented by combining primitives, and relationships among spaces are represented only if shared primitives are detected. So relationships between complex three-dimensional objects in space is difficult to be defined through the feature models. In this study, Navigable space-relation model(NSRM) is developed, which is topological data model for efficient representation of spatial relationships between objects based on the network structure.

• Journal of IKEEE
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• v.24 no.2
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• pp.378-384
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• 2020

The location information of the people or mover is essential for supporting various smart mobility services in railway stations which are mostly underground. For this purpose, a smart braille block is proposed to identify the location of the mover of the people. In this paper, the frequency characteristics of each material of the upper and lower parts of the braille block are analyzed to examine the appropriate materials for railway history. In addition, the guidelines for actual manufacturing were derived by analyzing the separation distance between two RF sensors in the smart braille block. As a result of analysis through the characteristic analysis in this paper, after selecting the material suitable for the construction site when the smart braille block is applied, the performance change of the RF system, especially the antenna that greatly influences the RF performance, must be reviewed in advance. It seems to have to be applied after checking through.

• Journal of Korean Clinical Health Science
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• v.1 no.2
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• pp.31-37
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• 2013

Purpose. This study was to investigate the analysis of the central corneal thickness and anterior chamber depth of eyes in Korean Young Population using the Pentacam topography. Methods. The subjects consisted of 126 eyes from normal cornea of Korean aged 7-12($8.857{\pm}1.501$) years during 2009. The thinnest location, pachy apex, and pupil central region of the cornea thickness was measured using the Pentacam pachymetry. The anterior chamber depth of normal corneas was measured with Pentacam. Results. The thinnest location of corneal thickness was $547.413{\pm}37.893$um. The pachy apex of cornea thickness was $552.103{\pm}36.016$um. Also, the pupil center of corneal thickness was measured $552.143{\pm}36.418$um. On the other hand, the mean thickness in the central cornea was a statically significant relationship(t-test, p=0.0002) between pachy apex and thinnest zone. Also the mean thickness of the central cornea was a statically significant correlation(pearson p=0.0001) among the pupil center, pachy apex and thinnest zone. The anterior chamber depth was $3.137{\pm}0.308$mm. The mean depth in the anterior chamber of cornea was a statically relationship(t-test, p>0.05) between OD and OS. Conclusions. The results of this clinical study suggested that the analysis of the central corneal thickness and anterior chamber depth using Pentacam in Korean young population can provide the useful morphological information in diagnosis of cornea for the contact lens fitting and corneal refraction surgery.

• Environmental and Resource Economics Review
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• v.15 no.1
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• pp.1-26
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• 2006

This paper explores the relatilonship between state level environmental regulations and stocking and location decisions in the U.S livestock and poultry industry (beef, chicken, dairy and hogs), Rather than conduct this analysis on a species by species basis, the overall size of the livestock industry(expressed in animal units) and the size of Industry found on large, medium and small operations by state (48) and over time (29 years), which is panel data analysis, Generally, regulations seem to be induced by the structural change of industry; when industry creates externalities, regulators try to address them with policy tools to internalize them, Written regulatory stringency may not effect behavioral change; rather the state's willingness to enforce regulations seems to have a measurable influence. However, in the presence of rapid structural change, industry location is affected by written regulatory stringency. Policy enforcement activity was shown to influence inventory decisions in general and larger operations were found to be more sensitive to willingness to enforce than smaller operations.

• Journal of the Korean Regional Science Association
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• v.8 no.1
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• pp.31-50
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• 1992

The aim of this paper is to define major factors influencing land development of each of major uses (residential, commercial, industrial) in the process of rapid urban expansion. The main hypothesis of this study is that land use changing patterns are directed by supply side of land managed to public policies rather than demand side. The graphic analysis is applied to relationships between urban growth and land development process of each use and between land development project managed to public policies and land development process. Public and land development projects and zonning protection seem to be major roles of land supply and main determinants of urban spatial structure. Location factors for land development of each uses are selected in 23 variables. Factor analysis is applied to test correlation between variables in 1971 and 1981. Factor structure between two years is similar, but progressive processing of functional separation is derived such as intensive land use is grouped, different location between residential and industrial use is deep. Dependent variables are standardized to logarithm of land development of each use per unit vacant land in two periods, between 1971 and 1980 year and between 1981 year. Correlation analysis between 6 dependent variables and 23 location factors in each years are applied. Major factors of each use are selected in criteria such as high correlation with dependent variables, low correlation between independent variables and common application in two periods. As the result, major factors for residential land development are Land Readjustment Project (LRP), percent of total zoned area in residential zone, residential floor space density per available area, percent of total area in industrial use; for commercial development is distance to CBD, percent of total area in commercial use, residential floor space density per available area in each year, and volumn rate of industrial use; for industrial use is percent of total area of industrial use is percent of total area of industrial use, Industrial Estate Project (IES), LRP, and distance from CBD. Land development pattern of each use between two periods are slightly different. So 6 equation is derived from appling backward method of regession. Adjusted multiple R squares of all is more than 0.5 and those equation is statistically significant and valuable to assist urban land use forecasting.

• Spatial Information Research
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• v.22 no.3
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• pp.1-8
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• 2014

While SNS services such as Twitter or Facebook are rapidly growing, research for the SNS analysis has been concerned. Especially, twitter reacts to social issues in real-time so that it is used to get useful experimental data for researchers of social science or information retrieval. However, it is still lack of research on the methodology to collect data. Therefore, this paper suggests the tweet acquisition system by considering tendency of twitter user oriented location-based event and political social event. First the system acquires tweets including information of location and keyword about event and secure IDs for acquisition of political social event. Then we plan ID-analyzer to classify the tendency of users. In addition for measuring reliability of ID-analyzer, it acquires and analyzes the tweet by using high-ranked ID. In analyses result, top-ranked ID shows 88.8% reliability, 2nd-ranked ID shows 76.05% and ID-analyzer shows 77.5%, it shortens collection time by using minority ID.

• Journal of Korean Tunnelling and Underground Space Association
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• v.4 no.1
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• pp.27-35
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• 2002

For the excavation of the rock, blast method is put into operation in most of the construction site in Korea. In comparison to other methods of excavation, blast method has many merits such as improvement in efficiency in operation, reducement of operation period, and etc. However, blast operation also creates much loss due to the blast vibration, noise, and fly rocks. Thus, in this study, we have examined main features, rock fragmentation effect and the application of plasma method the one of shallow vibration method. In this study, the attenuation exponent of blast method operated in the site was 1.39~1.40 and that of the plasma method was analysed to be 1.45~2.23. From the location where the distance between excavation location and observation location was over 15 m, most of excavation vibration were measured to be less than 0.2 kine(cm/sec), which is also the allowed standard value of sensitive buildings, such as cultural assets and computer facilities. According to the result of FFT(Fast Fourier Transform) analysis, the frequency measured through blast method in this site was 30~50 Hz and the frequency of plasma method ranges in between 30~130 Hz.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.2
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• pp.213-219
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• 2013

Recently, with the rapid advancement in information and communication technology, indoor location-based services(LBSs) that require precise position tracking have been actively studied with outdoor-LBS using GPS. However, in case of a ship which consists of steel structure, it is difficult to measure a precise localization due to significant ranging error by the diffraction and refraction of radio waves. In order to reduce location measurement errors that occur in these indoor environments, this paper presents distance compensation algorithms that are suitable for a narrow passage such as ship corridors without any additional sensors by using UWB(Ultra-wide-band), which is robust to multi-path and has an error in the range of a few centimeters in free space. These improvement methods are that Pythagorean theory and adjacent node technique are used to solve the distance error due to the node deployment and distance variation analysis technique is applied to reduce the ranging errors which are significantly fluctuated in the corner section. The experimental results show that the number of nodes and the distance error are reduced to 66% and 57.41%, respectively, compared with conventional CSS(Chirp spread spectrum) method.