• Journal of the Korea Society of Computer and Information
• /
• v.24 no.7
• /
• pp.125-133
• /
• 2019

Because military weapons systems for special purposes are small and complex, they are not easy to maintain. Therefore, it is very important to maintain combat strength through quick maintenance in the event of a breakdown. In particular, naval ships are complex weapon systems equipped with various equipment, so other equipment must be considered for maintenance in the event of equipment failure, so that skilled maintenance personnel have a great influence on rapid maintenance. Therefore, in this paper, we analyzed maintenance data of defense equipment maintenance information system through text mining and social network analysis(SNA), and tried to identify the naval ship maintenance expertise. The defense equipment maintenance information system is a system that manages military equipment efficiently. In this study, the data(2,538cases) of some naval ship maintenance teams were analyzed. In detail, we examined the contents of main maintenance and maintenance personnel through text mining(word cloud, word network). Next, social network analysis(collaboration analysis, centrality analysis) was used to confirm the collaboration relationship between maintenance personnel and maintenance expertise. Finally, we compare the results of text mining and social network analysis(SNA) to find out appropriate methods for finding and finding naval ship maintenance expertise.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.3D
• /
• pp.317-323
• /
• 2008

Mass transit information can contribute many benefits to users. Especially, transportation information technology is developing highly with information technology in Korea recently. Hereafter, it is expected to give customized transportation information to users individually with the advent of ubiquitous age in earnest. This public transportation information service can be realized by path finding algorithm in public transportation networks including travel and transfer attributes. In this research, constraints are constructed with the primary facts influencing users. Moreover, the method reducing user's path finding condition arbitrarily is proposed by making the maximum value as variables. In this study, transfer frequency, total travel time, seat confirmation, transfer time and travel time become constraint condition based on k path finding algorithm considering service time constraint condition. Moreover, case study about user customized transfer information is performed in Seoul and metropolitan subway networks.

• Proceedings of the Korean Society for Language and Information Conference
• /
• 1996.02a
• /
• pp.177-186
• /
• 1996

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.6
• /
• pp.627-635
• /
• 2017

Modern warfare is gradually changing into a network war, and information electronic warfare is also progressing. In modern war, electronic warfare is all military activity concerned with electromagnetic field use, such as signal collecting, communication monitoring, information analysis, and electronic attack. The one key function of signal collecting for enemy signal analysis, direction finding, collects the signal radiated from enemy area and then calculates the enemy direction. This paper examined the Watson-Watt algorithm for an amplitude direction finding system and CVDF algorithm for phase direction finding system and analyzed the difference in the direction finding accuracy between in the clean electromagnetic field environment and in the real operating field environment of electronic warfare system. In the real field, the direction finding accuracy was affected by the reflected field from the surrounding obstacles. Therefore, this paper proposesan enhanced direction finding process for reducing the effect. The result of direction finding by applying the proposed process was enhanced above $1.24^{\circ}$ compared to the result for the existing process.

• 한국공간정보시스템학회:학술대회논문집
• /
• 2004.05a
• /
• pp.222-229
• /
• 2004

This study purports to analyze equally stressed surfaces in tension-membrane structures through a geometrically nonlinear approach. It adopts the formulation of a 4-node quadrilateral isoparametric plane stress element considering the orthotropic characteristic of membrane textures. Tension structures, which include cables and tension membranes, such as a cable dome initially exhibit unstable conditions because no initial internal stiffness such as bending stiffness is present. Such a structural system requires prestressing to the tension members to attain a stable state. A tension-membrane structure retains a stable three dimensional curved surface as a structural shape. This analytical process for finding the geometry is referred to as Shape Finding Analysis. In order to assess the validity of this study, we examine equally stressed surfaces of saddle and catenary shape shell structures and carry out pertinent stress analyses

• The KIPS Transactions:PartA
• /
• v.8A no.2
• /
• pp.179-188
• /
• 2001

We analyze the property of candidate node set in the network graph, and propose an algorithm to decrease shortest path-finding computation time by using multiple dynamic-range queue(MDRQ) structure. This MDRQ structure is newly created for effective management of the candidate node set. The MDRQ algorithm is the shortest path-finding algorithm that varies range and size of queue to be used in managing candidate node set, in considering the properties that distribution of candidate node set is constant and size of candidate node set rapidly change. This algorithm belongs to label-correcting algorithm class. Nevertheless, because re-entering of candidate node can be decreased, the shortest path-finding computation time is noticeably decreased. Through the experiment, the MDRQ algorithm is same or superior to the other label-correcting algorithms in the graph which re-entering of candidate node didn’t frequently happened. Moreover the MDRQ algorithm is superior to the other label-correcting algorithms and is about 20 percent superior to the other label-setting algorithms in the graph which re-entering of candidate node frequently happened.

• International Journal of Contents
• /
• v.1 no.2
• /
• pp.35-38
• /
• 2005

This paper describes a design of simple and precision direction finder that can be adapted to shipboard or mobile vehicles used for Electronic support measure, ELINT and radio signal monitoring systems. The direction finding technology has improved with monolithic integrated circuit, linear array antennas, and interferometer. Interferometer uses the phase-comparison principle and has a good direction finding accuracy but it has an ambiguity problem. We suggest a simple ambiguity solver using phase-comparison technology with amplitude-comparison principle. The direction finding device that has been designed by the suggested method has 0.7 degree RMS error in azimuth angle and 0.6 degree RMS error in elevation angle in 0.5 - 2.0 GHz.

• Journal of Elementary Mathematics Education in Korea
• /
• v.16 no.2
• /
• pp.269-293
• /
• 2012

This study is intended to figure out how the 6th grade students carry out newly added standards regard to the problem solving in the revised mathematics curriculum in 2007 and 2009, which are 'finding useless information in a given problem', 'finding insufficient information in a given problem', and 'posing new problem by changing conditions of the given problem.' In order to achieve this goal, we examined the characteristics of 200 elementary students' problem posing. We constructed and used the survey sheet which consisted of 6 items relevant to 'finding useless information in a given problem', 'finding insufficient information in a given problem', and 'posing new problem by changing conditions of the given problem.'

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.16 no.6 s.97
• /
• pp.549-555
• /
• 2005

This paper describes a microwave direction finding technology which is used for RF signal acquisition and monitoring systems. This paper suggests a direction finding method which use a combination of the amplitude-comparison technology and the phase-comparison technology. The amplitude-comparison technology uses the amplitude difference of the RF signals received from the array antennas of direction finding system and removes the ambiguity of wave incident bearing. The phase-comparison technology uses the phase difference of the RF signals received from the same nay antennas and makes a good direction finding accuracy. The suggested direction finding technology is designed to place 8 array antennas in a $45^{\circ}$ distance around the circle for $360^{\circ}$ azimuth angle. Also it is designed to use the phase difference of the received signals ken two nearby antennas to measure the signal incident direction accurately and to use the amplitude difference to remove the ambiguity of wave incident bearing. The simulation and measurement results are under $0.5^{\circ}$ bearing error in $2.0\~6.0$ GHz when SNR is 30 dB.

• Journal of Korean Society of Archives and Records Management
• /
• v.3 no.1
• /
• pp.93-109
• /
• 2003

Finding aids have existed from the time when ancient archives appeared, With this long history, they have been used in most of Western archives, and thus, it is one of the most familiar tasks generally performed by archivists. However, ironically, this accustomed concept has not been an academic object to many researchers. Especially, in this electronic age, finding aids are even more complicated in their forms and meanings. This paper intends to address the concept(s) of finding aids as reflected in the archival literature in North America. The paper will attempt to illustrate how the concept of finding aid has evolved both conceptually and practically in archives and archival science and how circumstantial and social elements affect this concept. It Seems that the concept of finding aids has developed from the broad and integrated concept of provenance and pertinence to the narrower and practical sense considering the use by the public. It also turns out that the concept has advanced from a mere technical tool for describing records to an access tool for maximum availability. Not surprisingly, the concept of finding aids have changed as archival science and the profession has advanced and diversified. It is crucial for the archival community to understand changes in the practice and the concept of finding aids that will enable the preparation of higher quality finding aids enabling the optimum use of archives.