• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.6
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• pp.1055-1060
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• 2020

This study is a study on the analysis and measurement of the radar cross-sectional area of a miniature aircraft. Radar cross-sectional area for miniature aircraft in advance were analyzed using an electromagnetic analysis tool, and an actual miniature aircraft was manufactured and measured in an anechoic chamber. When measuring, the old model was used as reference data for RCS(radar cross section) characteristics and applied to the test result data of the actual reduced model. The measurement method improved the accuracy of the measurement by applying time gating to remove the influence on the components scattered inside the anechoic chamber. The RCS test results of the reduced model showed relatively high RCS characteristics in the microwave band, as the previous analysis results. In the future, we plan to utilize the method of RCS analysis and measurement for the target of the radar in the VHF(Very High Frequency)/UHF(Ultra High Frequency) band with a relatively large wavelength.

• Korean Journal of Remote Sensing
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• v.39 no.3
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• pp.339-353
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• 2023

As the availability of high-resolution satellite imagery increases, improvement of positioning accuracy of satellite images is required. The importance of orthorectified images is also increasing, which removes relief displacement and establishes true localization of man-made structures. In this paper, we performed automated extraction of building rooftops and total building areas within original satellite images using the existing building height database. We relocated the rooftop sin their true position and generated an orthorectified building layer. The extracted total building areas were used to blank out building areas and generate true orthographic non-building layer. A final orthorectified image was provided by overlapping the building layer and non-building layer.We tested the proposed method with KOMPSAT-3 and KOMPSAT-3A satellite images and verified the results by overlapping with a digital topographical map. Test results showed that orthorectified building layers were generated with a position error of 0.4m.Through the proposed method, the feasibility of automated true orthoimage generation within dense urban areas was confirmed.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.20 no.4
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• pp.159-172
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• 2009

This paper strives to shed a light on current academic resource sharing initiatives, and seeks the measure for the cooperative information resource management. It first attempts to draw outcomes and suggestions on the basis of issues and implications identified through the analyses in the aspects of management, service, and infrastructure of academic resource sharing in other countries. For this job, research methods such as interviews and on/offline literature review are employed. Specific projects to be analyzed via literature and web site review, although not detailed in nature, are National Technical Information Service(NTIS) and The National Science Digital Library(NSDL) in the United States, Intute of United Kingdom, and Australian Research Repositories Online to the World(ARROW) of Australia. Next, the paper discusses such an issue as the orientation of national level academic resource sharing initiatives based on the comparison of characteristics of current academic resource sharing project. For this, a thorough comparison on background, outlines and characteristics of the projects and analysis on the specifics of each project were conducted as well.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.6
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• pp.961-973
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• 2023

With the changes in the modern computing landscape, securing containerized workloads and addressing the complexities of container networking have become critical issues. In particular, the complexity of network policy settings and the lack of cloud security architecture cause various security issues. This paper focuses on the importance of network security and efficiency in containerized environments, and analyzes the security features and performance of various container network interface plugins. In particular, the features and functions of Cilium, Calico, Weave Net, and Kube-router were compared and evaluated, and the Layer 3/4 and Layer 7 network policies and performance features provided by each plugin were analyzed. We found that Cilium and Calico provide a wide range of security features, including Layer 7 protocols, while Weave Net and Kube-router focus on Layer 3/4. We also found a decrease in throughput when applying Layer 3/4 policies and an increase in latency due to complex processing when applying Layer 7 policies. Through this analysis, we expect to improve our understanding of network policy and security configuration and contribute to building a safer and more efficient container networking environment in the future.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.5
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• pp.41-46
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• 2023

It is very important to meet the maximum detection range in a radar system. In order to meet the maximum detection Range, the sensitivity of the received signal of the radar system must be high. In addition, the dynamic range should be wide in the radar signal processing board. To meet these requirements, the signal processing board must be designed to be robust against external and internal noise. In particular, a design is required to minimize the effect of noise generated by various switching circuits inside the board on the received radar signal. In this paper, we derive the requirements of the signal processor board to meet the radar system performance and describe the design to meet the derived requirements. In addition, the EMC design to minimize the influence of noise input from the outside or generated from the inside is described. Confirm the secured performance through the test of the manufactured board.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.11
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• pp.24-35
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• 2012

In this paper, we propose a dynamic lane control scheme with a traffic predictor module and a rate controller for reconciling with commercial optical PHY modules in energy efficient optical Ethernet systems. The commercial high speed optical Ethernet system capable of 40/100Gbps employs 4 or 10 multiple optical transceivers over WDM or multiple optical links. Each of the transceivers is always turned on even if the link is idle. To save energy, we propose the dynamic lane control scheme. It allows that several links may be entirely turned off in a low traffic load and frames are handled on the remaining active links. To preserve the byte order even if the number of active links may be changed, we propose a rate controller to be sat on the reconciliation sublayer. The main role of the controller is to insert null byte streams into the xGMII of inactive lanes. For the PHY module, the null input streams corresponding to inactive lanes will be disregarded on inactive PMDs. It is very handy to implement the rate controller module with MAC in FPGA without any modification of commercial PHYs. It is very crucial to determine the number of active links based on the fluctuated traffic load, we provide a simple traffic predictor based on both the current transmission buffer size and the past one with different weighting factors for adapting to the traffic load fluctuation. Using the OMNET++ simulation framework, we provide several performance results in terms of the energy consumption.

• Journal of Applied Biological Chemistry
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• v.55 no.1
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• pp.41-46
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• 2012

Arabinoxylan (Ara) rice bran has been shown to be a potent biological response modifier as manifested by stimulation of different arms of the immune system. We examined the effects of Ara rice bran and exercise on the immune function and cytokines in lipopolysaccharide (LPS)-stimulated rats. As the results, tumor necrosis factor-${\alpha}$ as representative inflammatory cytokines showed a significantly lower in Ara supplement group, thus the Ara rice bran had a higher inhibitory activity than the both exercise and control group. However, 4 weeks of exercise training significantly increased inflammatory reactions rather than treatment with Ara in LPS-treated rats. The Ara rice bran acted to decrease the inflammatory reaction. These results suggest that the supplement of Ara rice bran is likely contribute to inflammation response and the Ara rice bran can be used as a possible safe alternative to the immunotherapeutic modalities.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.2
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• pp.144-150
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• 2013

Hybrid ceramic membrane (HCM) processes that combined ozonation with a ceramic membrane (CM) or a reactive ceramic membrane (RM), an iron oxide nanoparticles (IONs) incorporated-CM were investigated for membrane fouling control. Alumina disc type microfiltration and ultrafiltration membranes doped with IONs by sintering method were tested under varying mass fraction of IONs. Scanning electron microscope (SEM) images showed that IONs were well-doped on the CM surface and doped IONs were approximately 50 nm in size. Change in the pure water permeability of RM was negligible compared to that of CM. These results indicate that IONs incorporation onto CM had little effect on CM performance in terms of the flux. Natural organic matter (NOM) fouling and fouling recovery patterns during HCM processes confirmed that the RM-ozonation process enhanced the destruction of NOM and reduced the extent of fouling more than the CM-ozonation process by hydroxyl radical formation in the presence of IONs on RM. In addition, analyses of NOM in the feed water and the permeate showed that the efficiency of membrane fouling control results from the NOM degradation during HCM processes; leading to removal and transformation of relatively high contents of aromatic, high molecular weight and hydrophobic NOM fractions.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1069-1077
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• 2008

The railway abrasion measurement system have to satisfy two conditions to increase the measurement accuracy as follows. The laser region which is projected on the rail have to be extracted without the geometrical distortion. The mapping of the acquired laser region data on the rail profile have to be processed exactly. But, the conventional railway abrasion measurement system is deeply effected by the foreign substance( dust, rainwater, and so on ) on the railway or the sensitive response characteristic of the laser to the external measurement circumstance, and then the measurement errors arise from above factors. When the laser region is projected on the rail extracts from the acquired image, the interference of the light with the same frequency as the laser system occurs the serious problems. In the process of the mapping between the railway profile and the extracted laser region, the measurement accuracy is very highly effected by the geometrical distortion and the abnormal variation. In this Paper, we propose the novel method to increase the accuracy of the railway abrasion measurement dramatically. we designed and manufactured the high precision and fast image processing board with DSP Core and FPGA to measure the railway abrasion. The image processing board has the capability that the image of 1024X1280 from camera can be processed with the speed of 480 frame/sec. And, we apply the image processing algorithm base on the wavelet to extract the laser region is projected on the rail exactly. Finally, we developed high precision railway abrasion measurement system with the error range less than +/-0.5mm by which 2D image data is covered 3D data and mapped on the rail profile using the camera model and the perspective transform.

• Geophysics and Geophysical Exploration
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• v.9 no.4
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• pp.279-290
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• 2006

The borehole radar methods used to tunnel detection are mainly classified into borehole radar reflection, directional antenna, crosshole scanning, and radar tomography methods. In this study, we have investigated the feasibility and limitation of each method to tunnel detection through case studies. In the borehole radar reflection data, there were much more clear diffraction signals of the upper wings than lower wings of the hyperbolas reflected from the tunnel, and their upper and lower wings were spreaded out to more than 10m higher and lower traces from the peaks of the hyperbolas. As the ratio of borehole diameter to antenna length increases, the ringing gets stronger on the data due to the increase in the impedance mismatching between antennas and water in the boreholes. It is also found that the reflection signals from the tunnel could be enhanced using the optimal offset distance between transmitter and receiver antennas. Nevertheless, the borehole radar reflection data could not provide directional information of the reflectors in the subsurface. Direction finding antenna system had a advantage to take a three dimensional location of a tunnel with only one borehole survey even though the cost is still very high and it required very high expertise. The data from crosshole scanning could be a good indicator for tunnel detection and it could give more reliable result when the borehole radar reflection survey is carried out together. The images of the subsurface also can be reconstructed using travel time tomography which could provide the physical property of the medium and would be effective for imaging the underground structure such as tunnels. Based on the results described above, we suggest a cost-effective field procedure for detection of a tunnel using borehole radar techniques; borehole radar reflection survey using dipole antenna can firstly be applied to pick up anomalous regions within the borehole, and crosshole scanning or reflection survey using directional antenna can then be applied only to the anomalous regions to detect the tunnel.