• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.7
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• pp.1199-1205
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• 2001

There has been an increase in the public concern about possible health risks by electromagnetic exposure from mobile phones. Recently, several SAR measurement procedures have been proposed to demonstrate the compliance of mobile phone with safety limits. To determine the maximum localized SAR of a test mobile phone, the electric field distribution is measured in the head phantom with simulated tissue liquid using the probe The important parameters in SAR measurement are the E-field probe, the shape and size of phantom, the electrical parameters of simulated tissue liquid, and test position, etc. Therefore, in order to setup the measurement standard, the studies on these factors are required. In this paper, the effects of the maximum localized SAR on the test positions of mobile phones were analyzed by the numerical computation and the SAR measurement. From the results, the worst condition of commonly used positions was determined and the touch and tilted positions were adopted as test positions of the domestic SAR measurement standard.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.177-180
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• 2005

AIS needs high efficiency and safety in terms of operational management and, in the aspect of service range, it is time to minimize shadow regions through propagation evaluation of AIS transmitter. Thus this study analyzes shadow regions and the scope of propagation of waves from stations through the electric wave environment of AIS. First, this study examines the characteristics of AIS wave and draws up methods to analyze the scope of propagation of waves according to the characteristics. Second, this study finds out service regions and shadow regions of the 22 stations across the nation by analyzing the actual data based on climate and topography, Lastly, this study summarizes the results of wave conductivity evaluation and conductivity problems and proposes improvement measures.

• Korean Journal of Environmental Agriculture
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• v.30 no.4
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• pp.382-389
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• 2011

BACKGROUND: Light-emitting diodes (LEDs) with lower electric cost and the specific wavelength have been considering as a novel light source for plant production in greenhouse conditions as well as in a closed culture system. Supplementary lighting for day-length extension was considered as light intensity, light quality, and/or photoperiod control on plant growth and development. Effects of supplementary blue or red LED radiation with lower light intensity on growth of Ageratum (Ageratum houstonianum Mill., cv. Blue Field), African marigold (Tagetes erecta L., cv. Orange Boy), and Salvia (Salvia splendens F. Sello ex Ruem & Schult., cv. Red Vista) were discussed during sunrise and sunset twilight in the experiment. METHODS AND RESULTS: Supplementary lighting by blue and red LEDs for 30 (Treatment B30; R30) or 60 (Treatment B60; R60) min. per day were established in greenhouse conditions. Photosynthetic photon flux for supplementary radiation was kept at $15{\mu}mol\;m^{-2}\;s^{-1}$ on the culture bed. Natural condition without supplementary light was considered as a control. The highest shoot and root dry weights were shown in African marigold exposed by red light for 60 min. per day. Supplementary blue and red lighting regardless of the radiation time significantly stimulated development of lateral branches in African marigold. Stem growth in Ageratum and Salvia seedlings was significantly promoted by red radiation as well as natural light. CONCLUSIONS: Extending of the radiation time at sunrise and sunset twilight using LEDs stimulated reproductive growth of flowering plant species. Different characteristics on growth under supplementary blue or red lighting conditions were also observed in the seedlings during supplementary radiation.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.7
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• pp.339-344
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• 2016

With increasing complexity of automotive software it has become important issue in the automotive safety. So, Automotive SPICE process have been proposed to solve this problem. The integrated management system and tools are needed for perform the Automotive SPICE process. It is difficult to adopt an integrated management system and tools because small business are lack of human resource and tools. Therefore, HIS scope items comply with Automotive SPICE minimum requirement should be targeted for the small business. In this paper, an open-source system based on process management tool required to perform the Automotive HIS scope items is proposed. The proposed system can perform the Automotive SPICE HIS scope items are carried and it showed that satisfy the Automotive SPICE HIS scope items.

• Nuclear Engineering and Technology
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• v.50 no.2
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• pp.246-252
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• 2018

A series of simulated reactivity-initiated accident (RIA) tests on irradiated fully recrystallized boiling water reactor Zircaloy-2 cladding has been performed by means of the expansion-due-to-compression (EDC) test method. The EDC method reproduces fuel pellet-clad mechanical interaction (PCMI) conditions for the cladding during RIA transients with respect to temperature and loading rates by out-of-pile mechanical testing. The tested materials had a large variation in burnup and hydrogen content (up to 907 wppm). The results of the EDC tests showed variation in the PCMI resistance of claddings with similar burnup and hydrogen content, making it difficult to clearly identify ductile-to-brittle transition temperatures. The EDC-tested samples of the present and previous work were investigated by light optical and scanning electron microscopy to study the influence of factors such as azimuthal variation of the Zr-hydrides and the presence of hydride rims and radially oriented hydrides. Two main characteristics were identified in samples with low ductility with respect to hydrogen content and test temperature: hydride rims and radial hydrides at the cladding outer surface. Crack propagation and failure modes were also studied, showing two general modes of crack propagation depending on distribution and amount of radially oriented hydrides. It was concluded that the PCMI resistance of irradiated cladding under normal conditions with homogenously distributed circumferential hydrides is high, with good margin to the RIA failure limits. To further improve safety, focus should be on conditions causing nonfavorable hydride distribution, such as hydride reorientation and formation of hydride blisters at the cladding outer surface.

• Journal of Advanced Navigation Technology
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• v.17 no.6
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• pp.712-719
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• 2013

This paper studies the security module for the reliable transmission of the meter reading and the control data between the remote terminals and the upper server-side in smart water grid. The proposed security module was implemented to make it attachable to the remote terminal without security function. In particular, unlike the smart grid of electric field, the low power is considered due to the use of battery power in the smart water grid, and the ARIA-GCM-128 symmetric key method is adopted taking into the account that the damp and constrictive environments by the installed meter location in the underground occur a communication obstacle on building of the large-scale network system. The encryption module of this paper was devised to ensure the safety between the reading data on the terminal and the control data from the upper server, and secure the stability of the remote meter reading system by taking protection against an arbitrary alteration or modification.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.5
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• pp.797-804
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• 2019

The two Koreas agreed to pursue rail and road connections on September 19, 2018 in the Pyongyang Joint Declaration. In December 2018, they launched a joint investigation for the North Korean railway modernization project. The survey confirmed that the track condition is seriously aging so that it is impossible to operate, and the railway network is well connected to major cities. Therefore, it was reasonable to modernize the aging track of the existing railway network rather than construct a new railway network. This paper proposed the railway communication policy for the improvement of railway lines and the construction of the railway wireless network by analyzing the status of roadbeds and tracks in order to enhance interoperability for the inter-Korean railway connection and safety for preventing the railway accidents.

• Proceedings of KOSOMES biannual meeting
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• 2008.05a
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• pp.191-195
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• 2008

In Ansan (the headquarter of KORDI ; Korea Ocean Research & Development Institute), KOSC(Korea Ocean Satellite Center) is being prepared for acquisition, processing and distribution of sensor data via L-band from GOCI(Geostationary Ocean Color Imager) instrument which is loaded on COMS(Communication, Ocean and Meteorological Satellite); it will be launched in 2009. The basis equipment of KOSC(Electric power, Network, Security) has been constructed in 2007. KOSC is being constructed data processing and management system, GOCI L-band reception system, etc. The final object of KOSC is that maximize the application of GOCI.

• Journal of the Korean Solar Energy Society
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• v.33 no.3
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• pp.91-98
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• 2013

In this study, we have carried out development and performance evaluation of optimized MEMS(Multi-Effect-Multi-Stage) fresh water generator with $7m^2/day$ for solar thermal desalination system. The developed MEMS was composed of high temperature part and low temperature part. This arrangement has the advantage of increasing the availability of solar thermal energy. The MEMS consists of 2 steam generators, 5 evaporators, and 1 condenser. Tubes of heat exchanger used for steam generators, evaporators and condenser were manufactured by corrugated tubes. The performance of the MEMS was tested through in-door experiments, using an electric heater as heat source. The experimental conditions for each parameters were $20^{\circ}C$ for sea water inlet temperature to condenser, $8.16m^2$ /hour sea water inlet volume flow rate, $70^{\circ}C$ for hot water inlet temperature to generator of high temperature part, 3.6 4.8, 6.0 $m^2/hour$ for hot water inlet volume flow rate. As a result, The developed MEMS was required about 85 kW heating source to produce $7m^2/day$ of fresh water. It was analyzed that the performance ratio of MEMS was about 2.6.

• Journal of the Korean Geophysical Society
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• v.4 no.1
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• pp.1-10
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• 2001

A number of tangible cultural properties have been left to suffering damage without any scientific conservation or maintenance. We conducted nondestructive geophysical explorations around the Western pagoda of the Iksan Mireuksa Temple for the purpose of preparing the counterplan of its conservation and maintenance and of utilizing the geophysical information for the design of repair. Geophysical image of the shallow subsurface around the construct resulting from electric resistivity, seismic refraction, and GPR methods carried out along 6 lines in the site was used to investigate the relationship between the foundation characteristics and the structural safety. Tilting of the pagoda southwest towards seems to result from the low resistivity zones found in the southwestern part. The GPR and seismic surveys revealed a boundary at depth of 3.3～3.5m dividing into two layers, compacted overlaid soil and the original ground. The boundary appears to dip southwest. The artificial layer as a foundation does not covers as much as the bottom area of the pagoda. This top soil dipping southwest seems to result in tilting of foundation southwestward towards. Our geophysical result suggests ground reinforcement in the western part of the survey area for the conservation of the construct.