• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.2
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• pp.22-28
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• 2007

High PAPR (peak-to-average power ratio) is a major drawback of OFDM (orthogonal frequency division multiplexing) signals. In this paper, a modified SLM (selective mapping) technique that uses erasure decoding of RS (Reed-Solomon) codes is presented. At the transmitter a set of phase sequences are multiplied such that some portions of check symbols in RS-coded OFDM data blocks are phase-rotated. At the receiver, RS decoding is performed with the phase-rotated check symbols being treated as erasures. Hence, there is no need to send side information about the phase sequence selected to transmit for the lowest PAPR. In addition, the estimation process for the selected phase sequence is no longer needed at the receiver, leading to improvement in terms of complexity and performance. To evaluate the performance of this technique, the CCDF (complementary cumulative distribution function) of PAPR, the BER (bit error rate) and the decoding failure probability are compared with those of the previous SLM techniques.

• Journal of Biosystems Engineering
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• v.31 no.6 s.119
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• pp.463-473
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• 2006

Automated sensing of soil macronutrients would allow more efficient mapping of soil nutrient spatial variability for variable-rate nutrient management. The capabilities of ion-selective electrodes for sensing macronutrients in soil extracts can be affected by the presence of other ions in the soil itself as well as by high concentrations of ions in soil extractants. Adoption of automated, on-the-go sensing of soil nutrients would be enhanced if a single extracting solution could be used for the concurrent extraction of multiple soil macronutrients. This paper reports on the ability of the Kelowna extractant to extract macronutrients (N, P, and K) from US Corn Belt soils and whether previously developed PVC-based nitrate and potassium ion-selective electrodes could determine the nitrate and potassium concentrations in soil extracts obtained using the Kelowna extractant. The extraction efficiencies of nitrate-N and phosphorus obtained with the Kelowna solution for seven US Corn Belt soils were comparable to those obtained with IM KCI and Mehlich III solutions when measured with automated ion and ICP analyzers, respectively. However, the potassium levels extracted with the Kelowna extractant were, on average, 42% less than those obtained with the Mehlich III solution. Nevertheless, it was expected that Kelowna could extract proportional amounts of potassium ion due to a strong linear relationship ($r^2$ = 0.96). Use of the PVC-based nitrate and potassium ion-selective electrodes proved to be feasible in measuring nitrate-N and potassium ions in Kelowna - soil extracts with almost 1 : 1 relationships and high coefficients of determination ($r^2$ > 0.9) between the levels of nitrate-N and potassium obtained with the ion-selective electrodes and standard analytical instruments.

• IEMEK Journal of Embedded Systems and Applications
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• v.3 no.2
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• pp.109-118
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• 2008

We present a robust localization algorithm using particle filter for mobile robots in a dynamic environment. It is difficult to describe moving obstacles like people or other robots on the map and the environment is changed after mapping. A mobile robot cannot estimate its pose robustly with this incomplete map because sensor observations are corrupted by un-modeled obstacles. The proposed algorithms provide robustness in such a dynamic environment by suppressing the effect of corrupted sensor observations with a selective update or a sampling from non-corrupted window. A selective update method makes some particles keep track of the robot, not affected by the corrupted observation. In a sampling from non-corrupted window method, particles are always sampled from several particle sets which use only non-corrupted observation. The robustness of proposed algorithm is validated with experiments and simulations.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.4
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• pp.493-498
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• 2011

This paper presents the GraphSLAM improved by selecting the measurement with respect to their likelihoods. GraphSLAM estimates the robot's path and map by utilizing the entire history of input data. However, GraphSLAM's performance suffers a lot from severely noisy measurements. In this paper, we present GraphSLAM improved by the selective measurement method. Thus the presented GraphSLAM provides higher performance compared with the standard GraphSLAM.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.11
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• pp.1525-1531
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• 2015

Using next-generation sequencing, we conducted a genome-wide scan of selective sweeps associated with selection toward genetic improvement in Thoroughbreds. We investigated potential phenotypic consequence of putative candidate loci by candidate gene association mapping for the finishing time in 240 Thoroughbred horses. We found a significant association with the trait for Ral GApase alpha 2 (RALGAP2) that regulates a variety of cellular processes of signal trafficking. Neighboring genes around RALGAP2 included insulinoma-associated 1 (INSM1), pallid (PLDN), and Ras and Rab interactor 2 (RIN2) genes have similar roles in signal trafficking, suggesting that a co-evolving gene cluster located on the chromosome 22 is under strong artificial selection in racehorses.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.183-185
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• 2002

The discovery of new ligands with affinity and selectivity for the dopamine $D_2$ receptor subtypes is an important area in medicinal chemistry. The distribution of the $D_2$ receptors in the limbic areas of brain suggests that these receptors may be particularly an attractive target for the design of potential selective antipsychotic drugs without causing extrapyramidal side effects. (omitted)

• Communications of the Korean Mathematical Society
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• v.16 no.2
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• pp.277-285
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• 2001

The purpose of this paper is to give a proof of a generalized convex-valued selection theorem which is given by weakening a Banach space to a completely metrizable locally convex topological vector space, i.e., a Frechet space. We also develop the properties of upper semi-continuous singlevalued mapping to those of upper semi-continuous multivalued mappings. These properties wil be applied in our further consideraations of selection theorems.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.11 s.102
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• pp.1147-1154
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• 2005

In this paper, we propose some PAPR(Peak to Average Power Ratio) reduction methods using WHT(Walsh Hadamard Transform) to reduce high PAPR generated in OFDM system because of multi carrier modulation. These proposed methods are the methods which has additional PAPR reduction performance without a loss of bandwidth efficiency and a large increment of calculation complexity than common PAPR reduction methods by combining the WHT with some common methods. In this paper, we propose two PAPR reduction methods made by combining a SLM(Selective Mapping) and DSI(Dummy Sequence Insertion) with a WHT. From simulation result, we can find that the PAPR reduction methods using a WHT can get about 1 dB additional PAPR reduction performance than common PAPR reduction methods; they are SLM and DSI. And, because our proposed methods have not only PAPR reduction effect, but also frequency diversity effect, more stabile data transmission is possible in nonlinear HPA and multipath fading channel.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.9
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• pp.27-34
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• 2011

Cognitive Radio, which is proposed to improve the efficiency of wireless communication systems is the system to share primary user's frequency bands with a secondary user. In this situation, a secondary user uses NC-OFDM (Non-contiguous Orthogonal Frequency Division Multiplexing) to transmit data effectively without interfering with the primary user's spectrum. However, NC-OFDM, in common with contiguous OFDM, degrades the performance of the system by generating high PAPR (Peak-to-Average Power Ratio). In this paper, firstly, we analyse PAPR corresponding to the distribution of subcarriers in NC-OFDM. Then the PAPR reductions that employ the PTS (Partial Transmit Sequence) and SLM (Selective Mapping) are evaluated. Finally, the computational complexities of the PTS and SLM adopting pruned-FFT are compared with conventional PTS and SLM. Further, it is shown that the NC-OFDM with pruned-FFT is more efficient than the contiguous OFDM in terms of computational complexity and PAPR reduction performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.12C
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• pp.1142-1148
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• 2007

In this paper, we propose ASLM (Adaptive Selective Mapping; ASLM) scheme based on peak observation for PAPR (Peak-to-Average Power Ratio) reduction of OFDM (Orthogonal Frequency Division Multiplexing) signals. The proposed scheme is composed of three steps: peak scaling, sequence selection, and SLM procedures. In the first step, the peak signal samples in the IFFT (Inverse Fast Fourier Transform) outputs of the original input sequence are scaled down. In the second step, the sub-carrier positions where the power difference between the original input sequence and the FFT output of the scaled signal is large, are identified. Then, the phase sequences having the maximum number of phase-reversed sequence words only for these positions are selected. Finally, the generic SLM procedure is performed by using only the selected phase sequences for the original input sequence. Simulation results show that the proposed scheme significantly reduces the complexity in terms of IFFT and PAPR calculation than the conventional SLM, while maintaining the PAPR reduction performance.