• Journal of Ecology and Environment
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• v.38 no.1
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• pp.95-107
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• 2015

Because an ecological community consists of diverse species that vary nonlinearly with environmental variability, its dynamics are complex and difficult to analyze. To investigate temporal variations of benthic macroinvertebrate community, we used the community data that were collected at the sampling site in Baenae Stream near Busan, Korea, which is a clean stream with minimum pollution, from July 2006 to July 2013. First, we used a self-organizing map (SOM) to heuristically derive the states that characterizes the biotic condition of the benthic macroinvertebrate communities in forms of time series data. Next, we applied the hidden Markov model (HMM) to fine-tune the states objectively and to obtain the transition probabilities between the states and the emission probabilities that show the connection of the states with observable events such as the number of species, the diversity measured by Shannon entropy, and the biological water quality index (BMWP). While the number of species apparently addressed the state of the community, the diversity reflected the state changes after the HMM training along with seasonal variations in cyclic manners. The BMWP showed clear characterization of events that correspond to the different states based on the emission probabilities. The environmental factors such as temperature and precipitation also indicated the seasonal and cyclic changes according to the HMM. Though the usage of the HMM alone can guarantee the convergence of the training or the precision of the derived states based on field data in this study, the derivation of the states by the SOM that followed the fine-tuning by the HMM well elucidated the states of the community and could serve as an alternative reference system to reveal the ecological structures in stream communities.

• Bulletin of the Korean Chemical Society
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• v.29 no.6
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• pp.1195-1198
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• 2008

Kinetic studies of the additions of benzylamines to a noncyclic dicarbonyl group activated olefin, methyl $\alpha$-acetyl-$\beta$ -phenylacrylates (MAP), in acetonitrile at 30.0 ${^{\circ}C}$ are reported. The rates are lower than those for the cyclic dicarbonyl group activated olefins. The addition occurs in a single step with concurrent formation of the $C_\alpha$ -N and $C_\beta$ -H bonds through a four-center hydrogen bonded transition state. The kinetic isotope effects ($k_H/k_D$ > 1.0) measured with deuterated benzylamines ($XC_6H_4CH_2ND_2$) increase with a stronger electron acceptor substituent ($\delta\sigma$ X > 0) which is the same trend as those found for other dicarbonyl group activated series (1-4). The sign and magnitude of the cross-interaction constant, ρXY, is comparable to those for the normal bond formation processes in the $S_N2$ and addition reactions. The relatively low ${\Delta}H^\neq$ and large negative ${\Delta}S^\neq$ values are also consistent with the mechanism proposed.

• ETRI Journal
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• v.37 no.3
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• pp.562-572
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• 2015

For a multiprocessor System-on-Chip (MPSoC) to achieve high performance via parallelism, we must consider how to partition a given application into different components and map the components onto multiple processors. In this paper, we propose a software pipeline-based partitioning method with cyclic dependent task management and communication optimization. During task partitioning, simultaneously considering computation load balance and communication optimization can cause interference, which leads to performance loss. To address this issue, we formulate their constraints and apply an integer linear programming approach to find an optimal partitioning result - one that requires a trade-off between these two factors. Experimental results on a reconfigurable MPSoC platform demonstrate the effectiveness of the proposed method, with 20% to 40% performance improvements compared to a traditional software pipeline-based partitioning method.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.160.2-160
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• 2001

This paper presents an individual cylinder spark advance control strategy based upon the location of peak pressure (LPP) in spark ignition engines using artificial neural networks. The LPP is estimated using a feedforward multi-layer perceptron network (MLPN), which needs only five samples of output voltage from the cylinder pressure sensor. The cyclic variation of LPP restricts the gain of the feedback controller, and results in poor regulation performance during the transient operation of the engine. The transient performance of the spark advance controller is improved by adding a feedforward controller which reflects the abrupt changes of the engine operating conditions such as engine speed and manifold absolute pressure (MAP)...

• Bulletin of the Korean Mathematical Society
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• v.45 no.3
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• pp.445-456
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• 2008

Let M be a right R-module, G an ordered group and ${\sigma}$ a map from G into the group of automorphisms of R. The conditions under which the Malcev-Neumann module M* ((G)) is a PS module and a p.q.Baer module are investigated in this paper. It is shown that: (1) If $M_R$ is a reduced ${\sigma}$-compatible module, then the Malcev-Neumann module M* ((G)) over a PS-module is also a PS-module; (2) If $M_R$ is a faithful ${\sigma}$-compatible module, then the Malcev-Neumann module M* ((G)) is a p.q.Baer module if and only if the right annihilator of any G-indexed family of cyclic submodules of M in R is generated by an idempotent of R.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.28 no.1
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• pp.31-41
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• 2002

The production of matrix matalloproteinases(MMPs) by the UV irradiated skin fibroblast and the degradation of extracellular matrix(ECM) by these enzymes is known as one of the main reasons of photoaging. Recently, Fisher group showed that the MMP expression is mainly regulated by the mitogen-activated protein(MAP) kinas family, such as extracellular signal-regulated kinase(ERK), c-Jun amino-terminal kinase(JNK) and p38, each of which forms a signaling pathway. In this work we first examined the effect of nitric oxide (NO) on the production of MMP-1 and MMP-2 by the human dermal fibroblasts (HDFs). NO is a multifunctional messenger molecule generated from L-arginine and involved in many kinds of signaling pathway. We found that the treatment of HDF with NO donor, sodium nitroprusside (SNP) enhanced the expression of MMPs with or without UV irradiation and the treatment with nitric oxide synthase (NOS) inhibitors resulted in the significant decrease of MMPs production. From these results, we concluded that the production of MMPs by the UV irradiated HDF is regulated through the signaling pathway involving NO and cyclic GMP.

• ETRI Journal
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• v.45 no.2
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• pp.213-225
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• 2023

Physical layer security (PLS) can improve the security of both terrestrial and nonterrestrial wireless communication networks. This study proposes a simplified framework for nonterrestrial cyclic prefixed orthogonal variable spreading factor (OVSF)-encoded multiple-input and multiple-output nonorthogonal multiple access (NOMA) systems to ensure complete network security. Various useful methods are implemented, where both improved sine map and multiple parameter-weighted-type fractional Fourier transform encryption schemes are combined to investigate the effects of hybrid PLS. In addition, OVSF coding with power domain NOMA for multi-user interference reduction and peak-toaverage power ratio (PAPR) reduction is introduced. The performance of $\frac{1}{2}$-rated convolutional, turbo, and repeat and accumulate channel coding with regularized zero-forcing signal detection for forward error correction and improved bit error rate (BER) are also investigated. Simulation results ratify the pertinence of the proposed system in terms of PLS and BER performance improvement with reasonable PAPR.

• The Korean Journal of Pesticide Science
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• v.7 no.2
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• pp.75-82
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• 2003

We discuss that the growth inhibition activities against root and shoot of rice plant (Oryza sativa L.) and barnyard grass (Echinochloa crus-galli) by N-phenyl-3,4,5,6-tetrahydrophthalimide (A) and N-phenyl-3,4-dimethylmaleimide (B) derivatives with changing substituents can be explained and predicted using comparative molecular field analyses (CoMPA) method. And the results show that the cross-validation value, $q^2$ at three components and Pearson correlation coefficient, $r^2$ were rice plant: shoot; $r^2=0.987$, $q^2=0.387$ & root; $r^2=0.923$, $q^2=0.307$ and barnyard grass: shoot; $r^2=0.902$, $q^2=0.535$ & root; $r^2=0.900$, $q^2=0.450$, respectively. In addition, The activities of unknown compounds were predicted by CoMFA method. From the contour map of (A) derivatives, the selective factors to remove barnyard grass takes positive charge on the benzylic carbon atom (C27), negative charged carbon atom (C29) of meta position and steric bulky groups on the cyclic imino ring (C7-C8).

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.4
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• pp.367-375
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• 2002

Inverse kinematics is a very useful method for control]ing the posture of an articulated body. In most inverse kinematics processes, the major matter of concern is not the posture of an articulated body itself but the position and direction of the end effector. In some applications such as 3D character animations, however, it is more important to generate an overall natural posture for the character rather than place the end effector in the exact position. Indeed, when an animator wants to modify the posture of a human-like 3D character with many physical constraints, he has to undergo considerable trial-and-error to generate a realistic posture for the character. In this paper, the Inductive Inverse Kinematics(IIK) algorithm using a Uniform Posture Map(UPM) is proposed to control the posture of a human-like 3D character. The proposed algorithm quantizes human behaviors without distortion to generate a UPM, and then generates a natural posture by searching the UPM. If necessary, the resulting posture could be compensated with a traditional Cyclic Coordinate Descent (CCD). The proposed method could be applied to produce 3D-character animations based on the key frame method, 3D games and virtual reality.

• Clinical and Experimental Reproductive Medicine
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• v.32 no.2
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• pp.101-111
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• 2005

배 경: Pituitary adenylate cyclase-activating polypeptide (PACAP)은 양의 시상하부에서 추출된 신경펩타이드 호르몬으로 난소에도 존재하여 배양된 과립막 세포에서 스테로이드합성과 cyclic AMP 형성을 촉진함이 보고되었다. 목 적: 흰쥐 난소를 실험 모델로 사용하여 배란시 황체화호르몬 (luteinizing hormone; LH)에 의해 유도된 PACAP과 PACAP 수용체의 유전자 발현양상과 신호 전달경로를 규명하고자 하였다. 재료 및 방법: 미성숙 흰쥐의 배란전 난포를 체외 배양하면서 LH로 처리하고 PACAP 및 PACAP수용체의 유전자 발현을 보기 위해서는 Northern blot 분석과 in situ hybridization (ISH)을, 그리고 단백질 수준의 PACAP 검색을 위해서는 enzyme linked immunosorbent assay (ELISA) 분석을 이용하였다. 결 과: LH 처리 후 Northern blot상의 PACAP 유전자 발현은 6~9시간에 일시적으로 최고치에 도달하였으며 ISH로 보아 과립막 세포에서 발현됨을 알 수 있었다. ELISA 분석 상 PACAP 단백질도 LH처리 후 6~12시간에 최고치를 나타내었으며, PACAP 수용체 mRNA 역시 3~9시간에 최고치로 과립막 세포에서 발현되었다. Adenylate cyclase (AC) 억제제인 MDL12330A 처리시 LH로 발현된 PACAP mRNA가 감소되며, AC의 활성제인 forskolin 처리에는 LH시와 유사한 PACAP mRNA의 발현양상을 나타내었다. 그러나 protein kinase C (PKC)의 억제제인 chelerythrine과 2-0-tetradecanolphorbol-13-acetate (TPA) 처리로는 PACAP 의 유전자 발현에 영향을 주지 못하였다. 5-lipoxygenase의 억제제인 MK886이나 nordihydroguaiaretic acid (NDGA)로 처리한 결과 LH로 유도된 PACAP 유전자의 발현이 감소되었으나, cyclooxygenase의 억제제인 indomethacin은 별로 영향을 주지 못하였다. MEK와 p38의 억제제인 PD98059와 SB203580도 LH로 촉진 된 PACAP의 유전자 발현을 농도 의존적으로 억제하였다. 결 론 : 배란전 난포에서 PACAP과 PACAP 수용체의 유전자 발현은 모두 LH의 폭발적 분비에 의해 유도되어 일시적으로 과립막 세포에서 나타나 배란을 위한 국소적인 조절 작용을 할 것으로 추정되며, LH로 촉진된 PACAP 유전자 발현을 위한 신호전달은 cAMP-PKA, lipoxygenase 및 MAP kinase 경로를 통하는 것으로 사료된다.