• Molecules and Cells
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• v.21 no.1
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• pp.135-140
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• 2006

Cytoplasmic male sterility (CMS) in plants, which is due to failure to produce functional pollen, is a maternally inherited trait. Specific nuclear genes that suppress CMS, termed fertility restorer (Rf) genes, have been identified in several plants. In this study, Rfl-inked molecular markers in pepper (Capsicum annuum L.) were detected by bulked segregant analysis of eight amplified fragment length polymorphisms (AFLPs). Only AFRF8 was successfully converted to a cleaved amplified polymorphic sequence (CAPS) marker. This was named AFRF8CAPS and genotype determination using it agreed with that obtained with the original AFRF8. A linkage map with a total size of 54.1 cM was constructed with AFRF8CAPS and the seven AFLP markers using the Kosambi function. The AFRF8CAPS marker was shown to be closest to Rf with a genetic distance of 1.8 cM. These markers will be useful for fast and reliable detection of restorer lines during $F_1$ hybrid seed production and breeding programs in pepper.

• 한국공간정보시스템학회:학술대회논문집
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• 2007.06a
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• pp.71-77
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• 2007

USN은 유비쿼터스 환경의 기반기술로서 저전력, 저비용 등 소규모의 특성을 갖고, 기지국과 같은 기반시설이 아닌 Ad_hoc 기법을 통해 통신한다. 일반적으로 센서노드 네트워크 구성을 위해 인력을 동원한 현장실측이나 또는 무작위 설치로 인하여 시간과 비용의 낭비와 환경적인 피해가 발생한다. 또한 중계망의 노드장애 등 관리를 위한 모니터링에 있어 GIS의 분석과 가시화 기능을 적극 활용할 필요가 있다. 따라서 본 연구는 GIS를 이용하여 RF 전파의 경로손실을 측정하고 중계노드의 RSSI를 산출하였으며, 중계노드의 구성과 중계경로망도 제작기법을 제시하였다. 연구지역은 경북대학교권역이며 RF대역은 국제표준인 2.4GHz를 기준으로 하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.306-310
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• 2012

Location tracking system represents position by searching objects and humans. In this paper I would like to write about RF chip support Zigbee which is called CC2420. In simulated network circumstance, we can get the information about mobile-node by sending it to sink-node. Position finding is in error by 3m at outdoor environment. The error scale is acceptable within easy range of naked eyes. It can be overcome by using GPS information and Google maps with the wireless networking background.

• Journal of Biomedical Engineering Research
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• v.33 no.3
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• pp.148-154
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• 2012

Hemorrhagic shock is a primary cause of deaths resulting from injury in the world. Although many studies have tried to diagnose accurately hemorrhagic shock in the early stage, such attempts were not successful due to compensatory mechanisms of humans. The objective of this study was to construct a survival prediction model of rats in acute hemorrhagic shock using a random forest (RF) model. Heart rate (HR), mean arterial pressure (MAP), respiration rate (RR), lactate concentration (LC), and peripheral perfusion (PP) measured in rats were used as input variables for the RF model and its performance was compared with that of a logistic regression (LR) model. Before constructing the models, we performed 5-fold cross validation for RF variable selection, and forward stepwise variable selection for the LR model to examine which variables were important for the models. For the LR model, sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (ROC-AUC) were 0.83, 0.95, 0.88, and 0.96, respectively. For the RF models, sensitivity, specificity, accuracy, and AUC were 0.97, 0.95, 0.96, and 0.99, respectively. In conclusion, the RF model was superior to the LR model for survival prediction in the rat model.

• International Journal of Contents
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• v.5 no.2
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• pp.59-63
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• 2009

Since it is hard to use GPS for tracking mobile user in indoor environments, much research has focused on techniques using existing wireless local area network infrastructure. Signal strength received at a fixed location is not constant, so fingerprinting approach which use pattern matching is popular. But this approach has to pay additional costs to determine user location. This paper proposes a new approach to find user's location efficiently using an index scheme. After analyzing characteristics of RF signals, the paper suggests the data processing method how the signal strength values for each of the access points are recorded in a radio map. To reduce computational cost during the location determination phase, multidimensional indexes for radio map with the important information which is the order of the strongest access points are used.

• Proceedings of the KSMRM Conference
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• 2003.10a
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• pp.72-72
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• 2003

In SENSE, division process is used in order to get a raw sensitivity map. This process requires denominator which is estimated by "sum-of-squres". However, this image does not have uniformbrightness because of the non-symmetrical property of RF coil arrays. Thus, this study is focused on better estimation of the denominator image.

• Journal of Satellite, Information and Communications
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• v.8 no.2
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• pp.88-93
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• 2013

The wideband chirp signal generator to enhance the resolution of synthetic aperture radar of obtaining the earth observation image is needed. This paper deals with designing, manufacturing and testing the wideband digital chirp signal generator having high resolution for LEO earth observation satellite. The wideband digital chirp signal generator is implemented with the memory-map based structure which is mostly applied in the satellite, and consists of the digital module to generate the digital chirp signal and the RF module to perform the quadrature modulation. The I/Q signals stored in the memory of the digital module are D/A converted and delivered to be quadrature modulated with the reference signal of 1275 MHz in the RF module. Furthermore, the test bench and GUI to validate the signal generator function are also developed. It is found that the requirement of 144 MHz bandwidth for the digital chirp signal generator is well met. Finally it is noteworthy that the distortion occurred in the chirp signal generator was compensated by the pre-distortion compensation.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.431-436
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• 2021

In this study, a new shielding method was applied to an accessory device that produces electromagnetic waves in the magnetic resonance room to prevent the generation of artifact caused by electromagnetic waves. The research method applied a new shielding made of metal plating fiber to patient surveillance CCTVs without shielding technology, and obtained and evaluated noise map when the power was not cut off and when the new shielding technology was applied without shutting down the CCTV. As a result of the study, it was found that there was at least one group with significant differences. Type I and type III belonged to group 1 while type II belonged to group 2 in the Post-hoc analysis, which meant blocking power of the CCTV and the applying new shielding technology were in the same group. In conclusion, if electromagnetic waves are generated due to additional accessories in the scanning room, the shielding material proposed in this study should be applied which enables the electric state become similar to type I, not generating noise, thereby preventing the artifacts caused by electromagnetic waves.

• ETRI Journal
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• v.38 no.4
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• pp.634-644
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• 2016

Channel-based radio-frequency fingerprinting such as a channel impulse response (CIR), channel transfer function (CTF), and frequency coherence function (FCF) have been recently proposed to improve the accuracy at the physical layer; however, their empirical performance, advantages, and limitations have not been well reported. This paper provides a comprehensive empirical performance evaluation of RF location fingerprinting, focusing on a comparison of received-signal strength, CIR-, CTF-, and FCF-based fingerprinting using the weighted k-nearest neighbor pattern recognition technique. Frequency domain channel measurements in the IEEE 802.11 band taken on a university campus were used to evaluate the accuracy of the fingerprinting types and their robustness to human-induced motion perturbations of the channel. The localization performance was analyzed, and the results are described using the spatial and temporal radio propagation characteristics. In particular, we introduce the coherence region to explain the spatial properties and investigate the impact of the Doppler spread in time-varying channels on the time coherence of RF fingerprint structures.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.1
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• pp.11-22
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• 2017

In recent years, coastal dune erosion has accelerated as various structures have been developed around the coastal dunes. A land cover map should be developed to identify the characteristics of sand dunes and to monitor the condition of sand dunes. The Korean Ministry of Environment's land cover maps suffer from problems, such as limited classes, target areas, and durations. Thus, this study conducted experiments using RGB and multispectral images based on UAV (Unmanned Aerial Vehicle) over an approximately one-year cycle to create a land cover map of coastal dunes. RF (Random Forest) classifier was used for the analysis in accordance with the experimental region's characteristics. The pixel- and object-based classification results obtained by using RGB and multispectral cameras were evaluated, respectively. The study results showed that object-based classification using multispectral images had the highest accuracy. Our results suggest that constant monitoring of coastal dunes can be performed effectively.