• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2010.04a
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• pp.35-35
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• 2010

• Journal of Navigation and Port Research
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• v.27 no.3
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• pp.247-252
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• 2003

This paper is mainly concerned with the assessment of safe navigation between ships moving each other in restricted waterways. The numerical simulation of manoeuvring motion was conducted parametrically to propose an appropriate safe speed and distance, which is required to avoid sea accident under the different conditions, such as ship-velocity ratios, ship-length ratios, separation and stagger between ships. As for the calculation parameters, the ratios of velocity difference between two ships were considered as 0.6, 1.2, 1.5 and the ones of ship-length difference were regarded were regarded as 0.5, 1.0, 1.18. From the inspection of this investigation, it indicates the following result. Firstly, the separation between ships is more needed for the small vessel, compared to the large vessel. Secondly, the lateral distance between ships is necessarily required for the velocity ration of 1.2, compared to the cases of 0.6 and 1.5. The manoeuvring characteristics based on this investigation will be very useful for keeping the safety of navigation from the practical point of ships design and traffic control in confined water.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.6
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• pp.1-12
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• 2010

This study aims at analyzing the development status of surroundings of natural environment conservation areas and securing an adequate distance from development activities to conserve natural environment conservation areas efficiently or developing an improvement plan for setting conservation areas. Findings from the study shows that 1) rather than simply designating a legal natural environment conservation area, a conceptual scope approach of a "core area", "buffer area", and "transition area" such as in zoning of a "biosphere reserve" by UNESCO is recommended; 2) when setting an adequate range in a natural environment conservation area, it should be set by fully considering locational situation and the regional and environmental features of surroundings rather than setting a certain distance uniformly; 3) instead of designating wetlands only as a conservation area, entry and exit areas should be also included as buffer areas and in the case of wild animals, not only habitats but also feeding areas should be designated as conservation areas; and 4) an adequate horizontal separation space is important in the case of ground development, but for natural resources related to subterranean water and geological situation such as wetlands, an adequate vertical separation space should be fully considered.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.6
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• pp.345-354
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• 2018

It is conservative to say that lots of research is performed as measures to use UAV for application to the rapid spatial information and its application is faced with settlement stage to some extent. In addition, Korea Land and Geospatial Informatix Corporation autonomously produces work regulation which is applied to every kind of orders and National Geographic Information Institute (2018) has notified public surveying work instructions about unmanned aerial device for the rapid spatial information construction. The results acquired by UAV are comprised of contents about accuracy improvements for the orthophoto when reviewing pertinent regulations. The results acquired by UAV are comprised of contents about accuracy improvements for the orthophoto when reviewing pertinent regulations. As a result, it is known that error amount has been sharply increased from 400m separation distance, and this study proposes that cross flight is able to reduce irregular error occurrence as measures to acquire stable results.

• Journal of Korea Planning Association
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• v.53 no.7
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• pp.39-48
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• 2018

The purpose of this study is to verify the stable flight conditions of drones within a limited urban area by using the ICAO(International Civil Aviation Organization) reich model which is using to evaluate civil aircraft stability. The results of the study are summarized as follows. First, in order for the drones flying stably, the horizontal safety separation distance between a drone and another should be at least 1,852M. Second, assuming that no obstacles within 1,852M of horizontal space, two drones can be fly into upper and lower spaces. However there are obstacles such as buildings, it is impossible to secure a 1,852M distance between drones. Third, sensitivity analysis point out that the separation interval($s_x$) of drone aviation has the greatest influence on the TLS(Target Level of Safety). If future research is conducted to lower the numerical values, the safety distance between a drone and another drone will be drastically reduced, allowing more detailed urban space division, and will be presented as a scientific numerical value for establishing a dedicated path for the drones.

• Journal of Advanced Navigation Technology
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• v.21 no.1
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• pp.30-35
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• 2017

Radio navigation aids are very important elements to provide information necessary for safe navigation using radio waves. Recently, the number of radio equipment using radio waves is increasing, and the air frequency interference by adjacent channels is very high. In addition, the use of irregular jamming that threatening radio navigation aids and satellite navigation system frequency is rapidly increasing. Therefore, it is urgent to ensure the safety of air waves. In this paper, we investigated the characteristics and frequency of the domestic navigation system. And we were analyzed the geographical separation standard for implementation of analysis program. Also, we implemented a program for the geographical separation distance analysis that applying international standards and recommended practices.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.1079-1082
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• 2015

In Article 23 of Technical regulations for Telecommunication Line and Facilities, we have criteria of separation distance between telecommunication lines and power lines, and its related exceptional conditions. However, this is a conflicts condition with Article 32 that provides the type of indoor telecommunication cables such as twisted-pair cables and optical fiber cables. Also, it is frequently raised that exceptional condition related the PoE cables with up to 15.4W is improved to accept PoE cables with up to 30W. In this paper, we have proposed improvement plans of Technical regulations for separation distance between telecommunication lines and power lines by analyzing the variety of standard specifications at home and abroad.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.3
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• pp.295-304
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• 2008

This paper comprises two specific objectives. The first is to examine the applicability of Ordinary Kriging interpolation(OK) to finite element method that is based on variogram modeling in conjunction with different allowable limits of separation distance. The second is to investigate the accuracy according to theoretical variograms such as polynomial, Gauss, and spherical models. For this purpose, the weighted least square method is applied to obtain the estimated new stress field from the stress data at the Gauss points. The weight factor is determined by experimental and theoretical variograms for interpolation of stress data apart from the conventional interpolation methods that use an equal weight factor. The validity of the proposed approach has been tested by analyzing two numerical examples. It is noted that the numerical results by Gauss model using 25% allowable limit of separation distance show an excellent agreement with theoretical solutions in literature.

• Journal of Korean Society of Disaster and Security
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• v.11 no.2
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• pp.17-28
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• 2018

The purpose of this study is to investigate the effect of underground facilities around excavation zone on groundwater flow characteristics during excavation. The scenarios were constructed considering the size of the underground facility, the separation distance, and the hydraulic gradient. As a result, as the size of the underground facility increases, the difference of head and the hydraulic gradient become large. The shorter the separation distance of underground facility is, the more the difference of head and the hydraulic gradient occur. The effect of hydraulic gradient on model area was relatively small. As a result of analysis of groundwater flow rate for the scenario, groundwater flow rate tends to decrease as the size of underground facility increases or groundwater flow rate tends to decrease as the separation distance decreases. It is necessary to examine the effect of underground facilities on the groundwater flow analysis in the ground excavation.

• Journal of IKEEE
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• v.24 no.4
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• pp.1028-1033
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• 2020

The existing in-band interference reduction method recommends the physical separation distance between wireless devices and interference signals, and the interference can be suppressed through the separation distance. If the in-band interference signals can be reduced in a wireless device, a margin can be given to the physical separation distance. Since there is an effect of extending the receiver dynamic range of receivers, it is highly useful for interference reduction and improvement method. In this paper, the structure of an in-band analog IRM(Interference Reduction Module) is proposed and the design and implementation of the proposed analog IRM are described. To design an analog IRM, the interference reduction performance according to the delay mismatch, phase error and the number of delay lines that affect the performance of the analog IRM was simulated. The proposed analog IRM composed of 16 delay lines was implemented and the implemented IRM has the interference reduction performance of about 10dB for a 5G(NR-FR1-TM-1.1) signal having a 40MHz bandwidth at a center frequency of 3.32GHz. The analog IRM proposed in this paper can be used as an in-band interference canceller.