• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5534-5540
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• 2015

This In the railway signaling system, applications of axle counter in addition to track circuit goes on increasing for detecting train position. Consequently, this paper compares sensor methods of axle counter with between geo-magnetism method and proximity sensor method. And it presents differences and results, to improve reliabilities of train detection and axle counting. Also, this article presents an applied result which is based on field experience, with regard to installation, considering attachment condition of sensor part for accurate axle counting. This study acquires expandability that is able to perform not only axle counting function but also various other functions (direction detection of train, speed detection of train, and so on). It was a result of a change of design in order to judge phase difference of sensors, to improve reliability of axle counting. Furthermore, it does not subordinate to characteristics (type, weight of train). And it is confirmed that the omission of axle counting was not occurred in 350km/h. This was the result of Lab test after the construction of transfer equipment of trial axle and Test Bed for axle counting. Both of them are self-productions. Through this, it prepares foundation which is able to apply not only to train detection but also to speed of passing trains, formation number of trains, detector locking condition - when the train passes the section of switch point, and level crossing devices. Furthermore, it would be judged to contribute safety train operation if proximity sensor method applies to the whole railway signaling system from now on.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.1
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• pp.208-215
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• 2018

The causes of column shrinkage and the codes that have been studied up to now are discussed. The documents mentioned in the code deal with the drying shrinkage, creep, compressive strength and elastic modulus of the specimen, and the elastic deformation calculated from the structural analysis. However, the deformation due to the temperature caused by the long term monitoring is less than that caused by the factors generated by the previous studies. In the previous studies, it was found that dehydration shrinkage, creep, and elastic deformation were not considered for temperature-induced deformation, while for the specimen experiments, the temperature-related items were replaced with the humidity-related terms The compensation value by the proposed equation showed error of 4.9 mm in the upper direction and 1.0mm in the lower direction when calculating column shortening, and it was found that its value by the proposed equation almost coincided with the measurement value in Site. Therefore, it is necessary to further study the temperature that can be omitted in calculating the existing column shortening, to consider the influence factors, and to supplement the criteria for the temperature measurement of the structure as well as the specimen tests.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.11
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• pp.1016-1027
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• 2015

In this paper, a orbit determination process was carried out based on KARISMA(KARI Collision Risk Management System) developed by KARI(Korea Aerospace Research Institute) to verify the orbit determination performance of this system, in which radar tracking data of a space debris was used. The real radar tracking data were obtained from TIRA(Tracking & Imaging Radar) system operated by GSOC(German Space Operation Center) for the KITSAT-3 finished satellite. And orbit determination error was approximately 60m compared to that of the GSOC's orbit determination result from the same radar tracking data. However, those results were influenced due to the insufficient information on the radar tracking data, such as error correction. To verify and confirm it, the error analysis was demonstrated and first observation data arc which has huge observation error was rejected. In this result, the orbit determination error was reduced such as approximately 25m. Therefore, if there are some observation data information such as error correction data, it is expected to improve the orbit determination accuracy.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.3
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• pp.3-12
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• 2009

Soil is one of the Earth's most important resources. There are many differences among the soils of plains.like and hilly terrains, and therefore, accurate and comprehensive information on soil is essential for optimum and sustainable soil utilization. However, information on the soil of the hilly terrains of the Eastern Ghats of Tamil Nadu, India, is limited or absent. In the present study, Kolli hill, one among the hills of the Eastern Ghats, was soil.inventoried and mapped using a ground survey and remote sensing. Soil samples were collected and their physico.chemical properties analyzed according to the United States Department of Agriculture (USDA) standards. The soils were classified up to the family level. As a result of this study, 30 soil series belonging to ten sub.groups of five great groups and three sub.orders and orders each, were identified (classified to the family level) and mapped. Entisols, Inseptisols and Alfisols were the three orders, among which Entisols was the major one, occupying 75% of the area. Among the five great groups, Ustorthents occupied majority of the area (73%). Lithic Ustorthents and Typic Ustorthents were the two major sub.groups, occupying 40% and 26% of the total area, respectively. The present soil resource mapping of the Eastern Ghats of Tamil Nadu is a pioneer study, which yielded valuable information on the soil in this region.

• Korea journal of population studies
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• v.20 no.1
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• pp.5-25
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• 1997

The historical study reveals that our ancestors had maintained a system which could produce data on the number of population and households as well as on their characteristics. For example, such data on age structure of the population, number of births, number of deaths by age & sex, number of in & out migrants were found in an historical document for the year 755. The main purposes of maintaining the system at that time were taxation and conscription. As the system evolves, another function of identifying the legal status of people was also added. Looking into the figures for those days reveals that ommission rates of the number of population and households were high. Thus, in an effort to obtain a reliable data, the annual population survey system was introduced as of 1 September 1896. This date is now cerebrated as the Statistics Day. Since then, the survey system has been diversified. At the present time, there are three major data sources which produce the statistics on population and households: Civil Registration System (vital statistics), Resident Registratiton System (migration statistics) and Population Census. However, these three systems are found to have some problems to produce the accurate data. There are some inherent problems in the registration systems such as problems in its coverage, accuracies in contents and timeliness in reporting the vital events and publishing the results. The population census has also non-sampling errors such as errors in coverage, response and non-response. Apart from the above mentioned problems, there are also conflicting problems arised from having different three data source. We can find some overlapping problems in laws and difficulties in comparative studies between regions. In the future, these problems should be taken into consideration for the improvement of the quality of statistics on population and households.

• Korea journal of population studies
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• v.20 no.1
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• pp.27-46
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• 1997

It is generally known that the quality of Korean population census results is very high. The completeness of the census has been over 97% since 1960. The age errors are very low and they belong to the lowest group in the world. However, Korean census has several problems to be solved, which are suggested as the followings: 1) Since most Koreans are basically educated, we will be able to adopt the self-reporting survey method for the next census instead of the interview method. Then, we can save a lot of time and cost in a census. 2) We have to simplify, the items of age since the effects of the four age items (Korean ago, zodiac year at birth, birth date in solar or lunar calendar) are not large enough to compare to the investments of manpower and costs. 3) It should be helpful to improve the quality of census data if the post enumeration survey is conducted more successfully and the results evaluated for more items not only age are published. 4) For the reduction of the error rates for the age groups of infants, young children and the young labours who are moving frequently, we need some special items for the compliteness of the population census by age group. 5) We have to prepare and release the 1995 2% sample data file to the public users for the improvement of the usefuleness in time. Furtheremore, it is also very important for the research in the field of social sciences that the back series of 2% sample files from 1985 census data are reconstructed.

• Geophysics and Geophysical Exploration
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• v.20 no.2
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• pp.78-87
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• 2017

For efficient data processing, trace interpolation and regularization techniques should be antecedently applied to the seismic data which were irregularly sampled with missing traces. Among many interpolation techniques, MWNI (Minimum Weighted Norm Interpolation) technique is one of the most versatile techniques and widely used to regularize seismic data because of easy extension to the high-order module and low computational cost. However, since it is difficult to interpolate spatially aliased data using this technique, model-constrained MWNI was suggested to compensate for this problem. In this paper, conventional MWNI and model-constrained MWNI modules have been developed in order to analyze their performance using synthetic data and validate the applicability to the field data. The result by using model-constrained MWNI was better in spatially aliased data. In order to verify the applicability to the field data, interpolation and regularization were performed for two field data sets, respectively. Firstly, the seismic data acquired in Ulleung Basin gas hydrate field was interpolated. Even though the data has very chaotic feature and complex structure due to the chimney, the developed module showed fairly good interpolation result. Secondly, very irregularly sampled and widely missing seismic data was regularized and the connectivity of events was quite improved. According to these experiments, we can confirm that the developed module can successfully interpolate and regularize the irregularly sampled field data.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1995.10a
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• pp.111-121
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• 1995

In Extracting the dynamic parameters for estimating the load carrying capacity and integrity of bridges, both the instrumentation and the processing the data plays important role . When the fixed point can not be secured, it is difficult and expensive to measure dynamic displacements. Even if the displacement is obtained through the integration of the acceleration data, the results can be quite different from the real behavior, because the main frequency contents can be leaked during discretized data processing. The instrumentation is used for measurements, and every measurement involves error and uncertainty, such as systematic, conformance, environmental, observational, sampling, and ranmom error. Systematic and conformance error can be remedied through the proper sellection and installation of the instruments, but sampling and random errors could not have been corrected properly and it becomes the limitation for using acceleration data. In this paper, the errors which can be occurred in numerical processing of dynamic data are referred, and the method to sellect proper sampling rate for the structural frequency range are proposed. Using the proposed method, the displacement response of the structures can be economically obtained from the measured acceleration record, and this procedure can be used properly to estimate the integrity of the bridges and infrastructures subjected to dynamic loads.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.763-766
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• 2008

The success of a construction project depends on efficient construction supply chain and service informationalization as types and quantities of materials in construction industry geometrically increase because the size of the construction industry increasingly becomes huge, high-rise, and complex. However, the omission of data for each step and the lower effect occurs because of uncertainty and inaccuracy of information as compared to other industries. In addition, it takes many hours to manage the present material states. Currently, IT technology and various mobile devices are being developed through the automation system of next generation intelligent construction supply chain management for the effective supply chain information management but the confusion regarding the recognition and transmission of the supply chain information between the multiple materials and transportation equipment using the IT and wireless network technology occurred. Therefore, the objective of this study is to propose the recognition mechanism which can deduce processes which caused the confusion of the recognition and transmission with supply chain information and solve the problems originated from the processes so as to solve the problems related to the confirmation and the communication of the correct supply chain information.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.1
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• pp.3-12
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• 2014

Cadastre is a set of activity registering diverse land information in national scope land management works. A nation examine land information and register it in a cadastral book, and must update data when necessary to properly maintain the information. Currently, local governments execute work about parcels of land alternation by manual work based on KLIS road map. Therefore, it takes too much time-consuming and makes problem as missing lots of parcels of land alternation. This study suggests the method selecting the parcels of land alteration for Jinan-Gun of Jeollabuk-Do using the GIS spatial overlay and the following results are as belows. Firstly, the manual work on the parcels of land alteration was greatly improved through automatically extracting the number and area of parcels according to the land classification and ownership by GIS spatial overlay based on serial cadastral maps and KLIS road lines. Secondly, existing work based on KLIS road lines could be advanced by analyzing the parcels of land alternation using the actual-width of the road from new address system to consider all road area for study site. Lastly, this study can supply efficient information in determining the parcels of land alternation consistant with road condition of local governments by analyzing the number and area of parcels according to the land classification and ownership within various roadsides ranging from 3m, 5m, and 10m by GIS buffering method.