• Journal of Digital Convergence
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• v.12 no.1
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• pp.339-345
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• 2014

This study has a purpose that improves efficiency of energy management and adaptation followed by movement of node better than the various early studied routing techniques. The purpose of this paper is the technique that uses RSSI value and location of sensor that is received by each sensor node to routing. This sduty does not save node information of 1-hop distance. And it solves energy-inefficient traffic problem that happens during data exchange process for middle node selection in close range multi hop transmission technique. The routing protocol technique that is proposed in this study selects a node relevant to the range of transmission which is set for RSSI value that is received by each node and selects the closest node as a middle node followed by location data. Therefore, it is for not exhaustion of node's energy by managing energy efficiently and cutting data transmission consuming until the destination node.

• Pediatric Infection and Vaccine
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• v.18 no.1
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• pp.85-90
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• 2011

In 2008, the Joint United Nations Programme on HIV/AIDS (UNAIDS) estimated that about 430,000 children worldwide became infected with HIV, mostly through mother-to-child transmission (MTCT) during pregnancy, labor, delivery, or breastfeeding. The MTCT prevention program proved to be feasible and effective in reduction of perinatal HIV transmission. Three babies born from HIV-infected mothers were admitted to the National Medical Center in 2009. Only two women received antiretroviral (ARV) therapy during pregnancy, labor, and after delivery, and their infants received zidovudine (AZT) for 6 weeks. The outcome, after a follow-up period of 4 months to 16 months, was favorable in all patients. Thus, we emphasize the need for expansion of antenatal HIV screening of pregnant women, implemented for early HIV diagnosis and effective ARV therapy for reduction of perinatal HIV transmission.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.3
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• pp.543-548
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• 2017

In the conventional algorithm, the D2D message dissemination algorithm based on the Epidemic routing protocol frequently causes a problem of duplication of the received messages due to the overlaps of D2D transmission coverages. It is because all D2D devices that receive the messages perform relaying the message replicas to other D2D devices within their transmission range. Therefore, we herein propose the farthest-k relay selection algorithm to mitigate this message duplication problem. In the farthest-k relay selection algorithm, less than k devices within the D2D transmission range perform message relay. Furthermore, we perform comparative performance analysis between the conventional D2D data dissemination algorithm and our farthest-k relay selection algorithm. By using intensive MATLAB simulations we prove the performance excellency of our farthest-k relay algorithm compared with the conventional algorithm with respect to coverage probability, the total number of initially and duplicately received messages, and transmission efficiency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.5
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• pp.447-455
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• 2014

In this paper, we consider a representative integral imaging method in glasses-free 3D image processing and propose a prioritized transmission scheme for guaranteeing a received video quality in error-prone environments. According to the correlation of pixels consisting of each voxel of integral image, we set the priority differently and apply the modulation level according to this priority value. That is to say, the corresponding pixels with small variance are set to a high priority and transmitted by using a low level modulation that is robust under transmission errors, but the corresponding pixels with greater variance are set to a lower priority and transmitted by using a high level modulation that has a high bit error rate but fast transmission rate. Result shows that the proposed scheme that applies the error-robust modulation level to the important image bit stream with the high priority improves the peak to sidelobe ratio (PSR) of the received 3D image, compared with a typical method that use the same modulation level without distinction of priorities.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.2
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• pp.211-218
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• 2020

The radio wave propagation characteristics of the transmitter and receiver position change in the indoor environment were predicted through simulation, then the results obtained through the transmission loss measurement were compared and analyzed with the simulation results. The conference room was chosen as the environment for measuring transmission loss, and the radio transmission characteristics of the two environments were compared by selecting the exhibition hall without interior decorations and fixtures. In each indoor environment, the position of the transmitter chose two cases. One located in the center of the front wall and the other in the center of the side wall, and the position of the receiver moved along the centerline of the conference room and the side wall, measuring the receiving power. For each change in transmitter-receiver position, received power of 3GHz and 6GHz band were measured and compared with the simulation forecast results. The changes in received power at each receiving point were analyzed according to the location of the transmitter and the frequency band variation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.1
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• pp.124-131
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• 2015

In this paper, we proposed indoor positioning system using RSS(Received Signal Strength) positioning method and TSS(Transmission Signal Strength). The main point in the paper is to improve reliability of accuracy positioning with the area recognition algorithm and probabilistic algorithm, which can be effectively used indoor. In the test in 1-dimensional or 2-dimensional spaces, also we checked effective positioning system considered environment of propagation that is changed by reflection, refraction and multipath in according to space form. It is necessary to find place where urgent situation happen and quickly to respond the situation for patients or the weak. Therefore, we expect the positioning system proposed can apply to the field of traffic IT.

• Smart Structures and Systems
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• v.2 no.2
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• pp.101-113
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• 2006

Structural health monitoring results obtained with the electro-mechanical (E/M) impedance techniqueand Lamb wave transmission methods during fatigue crack propagation of an Arcan specimen instrumented with piezoelectric wafer active sensors (PWAS) are presented. The specimen was subjected in mixed-mode fatigue loading and a crack was propagated in stages. At each stage, an image of the crack and the location of the crack tip were recorded and the PWAS readings were taken. Hence, the crack-growth in the specimen could be correlated with the PWAS readings. The E/M impedance signature was recorded in the 100 - 500 kHz frequency range. The Lamb-wave transmission method used the pitch-catch approach with a 3-count sine tone burst of 474 kHz transmitted and received between various PWAS pairs. Fatigue loading was applied to initiate and propagate the crack damage of controlled magnitude. As damage progressed, the E/M impedance signatures and the waveforms received by receivers were recorded at predetermined intervals and compared. Data analysis indicated that both the E/M impedance signatures and the Lamb-wave transmission signatures are modified by the crack progression. Damage index values were observed to increase as the crack damage increases. These experiments demonstrated that the use of PWAS in conjunction with the E/M impedance and the Lamb-wave transmission is a potentially powerful tool for crack damage detection and monitoring in structural elements.

• Journal of Satellite, Information and Communications
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• v.12 no.4
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• pp.146-151
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• 2017

This paper proposes a transmission algorithm that optimizes transmission power and sub-channel allocation to maximize energy efficiency considering characteristics of the channel impedance of power lines in power line communication systems. Since the received power at the receiver is influenced by the characteristics of the power line channel, it is necessary to consider channel characteristics when developing a transmission strategy in a power line communication systems. In addition, the energy efficiency should be optimized while meeting the practical constraints, such as the maximum transmission power limit of the transmitter and minimum quality of service for each user. In the computer simulation, we confirm that the energy efficiency of the proposed algorithm is improved compared to baseline schemes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1784-1788
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• 2012

In this paper we considered condition for keep standard error probability in optical transmission system that applied on-off keying transmission which are modulated amplitude along the signal. we calculated received sensitivity of receiver in on-off keying transmission for optical detector have quantum efficiency belong 1 in optical transmission system. For BT is over 30, the number of photon is belong 10000 for maintain standard error probability. also we considered Also, we install a preamplifier to the receiver for considering the low output may be used with a light that was able to get results.

• IEIE Transactions on Smart Processing and Computing
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• v.6 no.1
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• pp.39-46
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• 2017

In this paper, we propose an integer frequency offset estimation and compensation method based on PLC preamble correlation in DOCSIS 3.1 Downstream system. The proposed method determines the PLC preamble subcarrier location recovered from PLC data and the one obtained from PLC preamble correlation. We showed the performance of PLC preamble detection in the received signal through the maximum value detection of PLC preamble correlation. Thus we can estimate and compensate for the integer frequency offset by computing the difference of PLC subcarrier locations.