• Journal of Korean Society of Water and Wastewater
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• v.31 no.6
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• pp.567-575
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• 2017

It is not cost effective to raise the density of catch basins in preparation for heavy rainfall in terms of construction and maintenance. Our researchers have developed the new catch basin for increasing interception capacity of runoff with internal filtration structure. To compare interception capacity of an existing catch basin with the invented catch basin, a hydraulic experiment device with 4% of road gradients and 0.2% of road gradients was constructed. For runoff conditions of 4.4 l/s, 6.7 l/s and 10.4 l/s, capability of runoff and separation capability of debris (sand and leaves) were evaluated. As the main experimental results, the effectiveness of the developed catch basin has been verified with an increase in interception rate of approximately 22% for the runoff of 6.7 l/s as heavy rainfall. However, the results of invented catch basin showed only 4.5% of settlement rate of debris regarding sand. Therefore, the authors proposed an improved tilted screen structure additionally. After reviewing the performance of improved catch basin, application of the invented catch basin is expected to drain runoff effectively when it is applied to the faulty road drainage section.

• Journal of the Korean Home Economics Association
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• v.38 no.1
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• pp.25-38
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• 2000

This study focuses on the Russian Constructivist Textile Design in the post-revolutionary period, of the early 20th century. Russian textile of the time is highly valued in the west in terms of innovative changes in aesthetic directions, which has become one of the most important centers for the development of new textiles, or the origin of industrial design. Most of brilliant mass-production patterns were produced specially by the pioneers of constructivists such as Stepanova and Popova who were influenced by 'Maxism' through the Revolution regarded themselves as productivists for the proletariat. They were inspired by the avant-garde movements, which were involved with traditionalism, futuristic mechanism, stylization of nature, pure geometrical and abstract form. Early textile design was based on the relationship between the graphic methods of design and the technology because they regarded art as physical, intellectual and technical production. They created all the excitement made from the primary simplest forms of precise mathmatical shapes, such as the circle, the triangle, the rectangle and horizontle and vertical lines. These geometric design can be interpreted as the mechanization of the artists'labor, or methods in line with the technology of mass production, however partly roots in the rich tradition of Russian decorative art. On the other hand, stable crystalline construction on the surface reflect urban architectural complex, and the world of industry in graphic form. They were interested in illusion of movement, cinematic movement of vertical linear rhythms, optical formations and vibrations, by composing a multi-leveled constructions by several spatial planes, or color-field, and combining structures of several intersecting matrices, and superimposing parts of the forms on each other. All these characteristics of the Russian textile designs reflect the complex interactions between 'art and society' of Constructivist's idea and represent the traits of the epoch.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.153-161
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• 2005

Recently, The government of Korea declared to develop RFID(Radio Frequency IDentification) as one of key strategic technology to perform U-Government using Ubiquitous technology. But, most of the related technologies for RFID are mainly focused on the inlaned application excepting marine applications. The last target of this study is to implement new Marine RFID(M-RFID) that can cover all of EEZ areas as large five times as inland volume. In this paper, as a basic study for the M-RFID, we carried out an establishing the concept design of M-RFID, developing the construction method of M-RFID and, extending the idea of M-RFID. As studying results, it is known that the M-RFID can be use in many practical areas such as the protection of EEZ area and aqua culture, the safety of fisher man, the disaster control for inlander and, fisheries ligistics with real-time.

• The Journal of Information Technology
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• v.4 no.2
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• pp.69-81
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• 2001

In this paper, we examine work in the evolution of content-based retrieval systems that rely on an intelligent infrastructure. Here, we refer to intelligence as the capabilities of the systems to build and maintain situational or world models, utilize dynamic knowledge representations, exploit context and overage advanced reasoning and learning capabilities. We argue that these elements are essential to producing effective systems for retrieving visual information at semantic levels matching those of human perception and cognition. In this paper, we review relevant research on the understanding of human intelligence and construction of intelligent systems in the fields of cognitive psychology, artificial intelligence, semiotics. We also discuss how some of the principal ideas from these fields lead to new opportunities and capabilities for content-based retrieval systems. Finally, we discribe some of our efforts in these directions. In particular, we present MediaNet, a multimedia knowledge presentation framework that facilitate and enable intelligent content-based retrieval.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.1
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• pp.57-68
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• 2004

Although variable-length codes (VLCs) increase coding efficiency using the statistical characteristics of the source data, they have catastrophic effects from bit errors in noisy transmission environments. In order to overcome this problem with VLCs, reversible variable-length codes (RVLCS) have recently been proposed owing to their data recovering capability. RVLCS can be divided into two categories: symmetrical and asymmetrical RVLCs. Although the symmetrical RVLC has generally more overheads than the asymmetrical RVLC, it has some advantages of simpler design and more efficient memory usage. However, existing symmetrical RVLCs still have high complexity in their code design and some room for improvement in coding efficiency. In this paper, we propose a new algorithm for constructing a symmetrical RVLC from the optimal Huffman code table. The proposed algorithm has a simpler design process and also demonstrates improved performance in terms of the average codeword length relative to the existing symmetrical RVLC algorithms.

• Spatial Information Research
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• v.16 no.4
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• pp.421-439
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• 2008

The objective of this project is to construct the intelligent underground facility management system based on UFSN (Underground Facility Sensor Network). Total project duration is 6-year. And first two years' project has been finished. First two years' project focused on water supply and sewage facilities among 7 underground facilities and investigated the fundamental construction technology for the underground facilities management system. To contribute the development of systematic and scientific management of underground facilities, KRIHS implemented 3 researches for 'Underground facilities management system for an intelligent city' like followings: (1) to investigate an integration plan for current water supply and sewage management systems, (2) to derivate of water supply and sewage monitoring items for the monitoring technology development, and (3) to implement a basic research for sensor installation plans on different types of current and new underground facility systems. This research paper contains the first two years' outcome of researches from KRIHS (Korea Research Institute for Human Settlements).

• Advances in aircraft and spacecraft science
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• v.4 no.4
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• pp.353-369
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• 2017

Flutter is a dangerous phenomenon encountered in flexible structures subjected to aerodynamic forces. This includes aircraft, buildings and bridges. Flutter occurs as a result of interactions between aerodynamic, stiffness, and inertia forces on a structure. In an aircraft, as the speed of the flow increases, there may be a point at which the structural damping is insufficient to damp out the motion which is increasing due to aerodynamic energy being added to the structure. This vibration can cause structural failure, and therefore considering flutter characteristics is an essential part of designing an aircraft. Scientists and engineers studied flutter and developed theories and mathematical tools to analyze the phenomenon. Strip theory aerodynamics, beam structural models, unsteady lifting surface methods (e.g., Doublet-Lattice) and finite element models expanded analysis capabilities. Periodic Structures have been in the focus of research for their useful characteristics and ability to attenuate vibration in frequency bands called "stop-bands". A periodic structure consists of cells which differ in material or geometry. As vibration waves travel along the structure and face the cell boundaries, some waves pass and some are reflected back, which may cause destructive interference with the succeeding waves. This may reduce the vibration level of the structure, and hence improve its dynamic performance. In this paper, for the first time, we analyze the flutter characteristics of a wing with a periodic change in its sandwich construction. The new technique preserves the external geometry of the wing structure and depends on changing the material of the sandwich core. The periodic analysis and the vibration response characteristics of the model are investigated using a finite element model for the wing. Previous studies investigating the dynamic bending response of a periodic sandwich beam in the absence of flow have shown promising results.

• Geomechanics and Engineering
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• v.19 no.6
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• pp.485-498
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• 2019

Pre-tensioned rock bolts can be classified into fully anchored, lengthening anchored and point anchored bolts based on the bond length of the resin or cement mortar inside the borehole. Bolts in varying anchoring methods may significantly affect the supporting effect of surrounding rock around a tunnel. However, thus far, the theoretical basis of selecting a proper anchoring method has not been thoroughly investigated. Based on this problem, 16 schemes were designed while incorporating the effects of anchoring length, pretension, bolt length, and spacing, and a systematic numerical experiment was performed in this paper. The distribution characteristics of the stress field in the surrounding rock, which corresponded to various anchoring scenarios, were obtained. Furthermore, an analytical approach for computing the active and passive strengthening index of the anchored surrounding rock is presented. A new fully anchoring method with pretension and matching technology are also provided. Then, an isolated loading model of the anchored surrounding rock was constructed. The physical simulation test for the bearing capacity of the model was performed with three schemes. Finally, the strengthening mechanism of varying anchoring methods was validated. The research findings in this paper may provide theoretical guidelines for the design and construction of bolting support in tunnels.

• Journal of the Korean Geotechnical Society
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• v.36 no.10
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• pp.41-56
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• 2020

For the rapid and accurate warning, the system requires not only the sufficient number of seismometers but also the appropriate detection technique of sensor data. Instead of installing new seismometers, on-board accelerometers of the train could be utilized as alternatives. However, the data from on-board accelerometers includes train vibrations and the response of embankment site by earthquake, which are different from earthquakes measured from the seismometer. This study suggests signal analysis technique to detect earthquake from the on-board accelerometer data. The virtual on-board accelerometer data including the response of embankment site, obtained from site response analysis method, has been constructed. The constructed data has been analyzed using short time Fourier transform (STFT) and wavelet transform (WT). STFT method provides better performance to detect long-period earthquake whereas WT method is more available to detect short-period earthquake.

• Journal of the Korean Institute of Gas
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• v.15 no.4
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• pp.56-61
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• 2011

For the prevention of air pollution, the CNG vehicles have been supplied since 2006. The spread of CNG vehicles has decreased the level of air pollution. Declared goals of Korean Ministry of Environment (ME) are to supply CNG city bus by 90% by 2012. CNG bus explosion has exacerbated commuters' safety concerns, it has caused the barrier to the installation of CNG station. In this study, the sensor was installed for the safety improvement of CNG station. When new sensors were installed, a problem was encountered by a line of communication. To solve the installation problem, we carried out the monitoring of data communication network by USN technology.