• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.3
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• pp.289-297
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• 2011

The explicit finite element method is an essential tool for solving large problems with severe nonlinear characteristics, but its results can be difficult to interpret. In particular, it can be impossible to evaluate its acceleration responses because of severe discontinuity, extreme noise or aliasing. We suggest a new post-processing method for transient responses and their response spectra. We propose smoothing methods using a Gaussian kernel without in depth knowledge of the complex frequency characteristics; such methods are successfully used in the filtering of digital signals. This smoothing can be done by measuring the velocity results and monitoring the response spectra. Gaussian kernel smoothing gives a better smoothness and representation of the peak values than other approaches do. The floor response spectra can be derived using smoothed accelerations for the design.

• Toxicological Research
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• v.17
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• pp.251-256
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• 2001

The expression of phase II detoxifying enzymes is affected by a variety of compounds and the induction of the enzymes plays an essential role in chemoprevention. A variety of phytochemicals such as sulfur-containing chemoprotective agents (SCC) may trigger cellular signals and activate phase II gene expression through ARE activation. see induces glutathione S-transferases. Studies were conducted to investigate the role of mitogen-activated protein (MAP) kinase and phosphatidylinositol 3-kinase (PI3-kinase) in the induction of GST (e.g. rGSTA2) by sec. We also studied the MAP kinase pathway responsible for the GST expression by see and compared that with the pathway activated by oxidative stress as a result of sulfur amino acids deprivation (SAAD). see inhibited phosphorylation of ERK1/2 although the effect of see on JNK and p38 MAP kinase was minimal. Wortmannin and LY294002. PI3-kinase inhibitors. abolished the increases in rGSTA2 mRNA and protein levels by SCC. Deprivation of cystine and methionine caused oxidative stress in H4IIE cells. as evidenced by a decrease in the reduced glutathione and an increase in prooxidant production. Electrophoretic mobility shift assay revealed that the ARE complex consisting of Nrf-1/2 and Maf proteins was activated 12~48 h. The rGSTA2 mRNA and protein levels were increased by SAAD. Activation of ARE and induction of rGSTA2 were both completely inhibited by PI3-kinase inhibitors. Inhibition of p38 MAP kinase by SB203580 prevented the ARE-mediated rGSTA2 induction. The results of this study showed that PI3-kinase might play an essential role in the ARE-mediated rGSTA2 induction by see or SAAD and that the dual MAP kinase pathways were responsible for the enzyme induction.

• Journal of Broadcast Engineering
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• v.11 no.2 s.31
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• pp.191-199
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• 2006

This paper presents an efficient pre echo control scheme for MPEG Audio coders based on the psychoacoustic model II (PAM-II). Pre echo control is the final step for the calculation of masking threshold in the PAM II. It is to minimize the spread of quantization error over the processing frame. In the conventional encoders, pre echo is reduced by restricting the estimated masking threshold not to exceed the one obtained in the previous frame. The conventional method performs pre echo control not only for short blocks but also for long blocks, which lowers the masking threshold in long blocks and, in turn, increases the quantization noise level of corresponding blocks. This paper proposes an efficient pre echo control process. The test result shows a mean enhancement of more than 0.4 especially for complex signals on the ITU R 5 point audio impairment scale.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.9
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• pp.1286-1293
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• 2014

Typically, studies through the simulation system have been progressed, because the evaluation of the driver's arousal state about the service of a actual train has risk of safety for the driver. When configured event same as the real in simulation system, the ability to cope with an accident situation may be the same each other. But the difference in the state of tension or arousal will occur. In this study, requested to cooperate with the railways in order to escape from these constraints, and the target of the experiment was to real engineer service. I was set about experiment when the train was stopped as safe as possible. As a result, the beta wave of EEG signals that representing complex calculations or anxiety is increased rapidly on the basis of a flag station from at the time of departure. The size of the electrodermal activity signal in response to movement of the body gave a noticeable. In terms of HRV, if the train approach a flag station gradually and the R-R interval is narrowed. So that the driver can be estimated as arousal state. In accordance with this study, if the quantitative standard of arousal state be based on the driver's biosignals will provide, it will be able to take advantage of development the system that would prevent train accidents caused by human error.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.6
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• pp.721-729
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• 2018

GABAergic control over dopamine (DA) neurons in the substantia nigra is crucial for determining firing rates and patterns. Although GABA activates both $GABA_A$ and $GABA_B$ receptors distributed throughout the somatodendritic tree, it is currently unclear how regional GABA receptors in the soma and dendritic compartments regulate spontaneous firing. Therefore, the objective of this study was to determine actions of regional GABA receptors on spontaneous firing in acutely dissociated DA neurons from the rat using patch-clamp and local GABA-uncaging techniques. Agonists and antagonists experiments showed that activation of either $GABA_A$ receptors or $GABA_B$ receptors in DA neurons is enough to completely abolish spontaneous firing. Local GABA-uncaging along the somatodendritic tree revealed that activation of regional GABA receptors limited within the soma, proximal, or distal dendritic region, can completely suppress spontaneous firing. However, activation of either $GABA_A$ or $GABA_B$ receptor equally suppressed spontaneous firing in the soma, whereas $GABA_B$ receptor inhibited spontaneous firing more strongly than $GABA_A$ receptor in the proximal and distal dendrites. These regional differences of GABA signals between the soma and dendritic compartments could contribute to our understanding of many diverse and complex actions of GABA in midbrain DA neurons.

• Journal of Astronomy and Space Sciences
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• v.31 no.4
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• pp.335-340
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• 2014

There have been many suggestions and much debate about climate variability during the Holocene. However, their complex forcing factors and mechanisms have not yet been clearly identified. In this paper, we have examined the Holocene climate cycles and features based on the wavelet analyses of $^{14}C$, $^{10}Be$, and $^{18}O$ records. The wavelet results of the $^{14}C$ and $^{10}Be$ data show that the cycles of ~2180-2310, ~970, ~500-520, ~350-360, and ~210-220 years are dominant, and the ~1720 and ~1500 year cycles are relatively weak and subdominant. In particular, the ~2180-2310 year periodicity corresponding to the Hallstatt cycle is constantly significant throughout the Holocene, while the ~970 year cycle corresponding to the Eddy cycle is mainly prominent in the early half of the Holocene. In addition, distinctive signals of the ~210-220 year period corresponding to the de Vries cycle appear recurrently in the wavelet distribution of $^{14}C$ and $^{10}Be$, which coincide with the grand solar minima periods. These de Vries cycle events occurred every ~2270 years on average, implying a connection with the Hallstatt cycle. In contrast, the wavelet results of $^{18}O$ data show that the cycles of ~1900-2000, ~900-1000, and ~550-560 years are dominant, while the ~2750 and ~2500 year cycles are subdominant. The periods of ~2750, ~2500, and ~1900 years being derived from the $^{18}O$ records of NGRIP, GRIP and GISP2 ice cores, respectively, are rather longer or shorter than the Hallstatt cycle derived from the $^{14}C$ and $^{10}Be$ records. The records of these three sites all show the ~900-1000 year periodicity corresponding to the Eddy cycle in the early half of the Holocene.

• Journal of Multimedia Information System
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• v.7 no.3
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• pp.221-230
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• 2020

Used optimization techniques as solution for mobile network have been implemented as a reference systems for various applications against fading and signals perturbation, in addition each transition to 5th generation telecommunication standards require a deep studies in order to park an applied instantaneous process. The paper describes a preliminary planning and a careful preparation to update both subscriber radio access network as well as data transmission network this approach conducts to make network resource updates invisible for customers and with minimal costs for mobile operators basically in terms of delay. In addition, network operators transit to mobile networks, multimedia services efficient delivery are considered the challenging application and the most promising for mobile network operators today, this work conduct to optimize video consumption of mobile users which are exponentially increasing. The interference is a complex phenomenon in mobile radio telecommunication system, and a mobile phone can be a source of interference to another one. Actual advances in technology necessitate the need for the complicated software solution that can take several unexpected phenomena in consideration to rise to a level higher than ever. The capability needs today require the use of Drive test which is used to take the performance of network in the field by using a special software called TEMS investigation, it have been implemented as standalone systems for various applications. The paper focuses on considering as the best technical for optimization of mobile networks, analysis and processing of signal, a Drive Test is the method used to take the performance of network in the field by using a special software called TEMS investigation. Most used in the world, this software is reputed to detect and analyze many problems of mobile network between the mobile phone and the transmitter: BTS in case of GSM and Node B for UMTS. An example of that is interference in radio communication. It exists permanently and it degrades considerably the quality of received signal when it exceeds certain levels.

• Korean Journal of Psychosomatic Medicine
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• v.7 no.2
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• pp.149-157
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• 1999

Food intake and body weight are determined by a complex interaction of regulatory pathways. Leptin, the product of the ob gene, is a recently discovered hormone secreted by adipocytes, that signals the amount of adipose tissue energy stores to the brain and exerts major effects on energy homeostasis and neuroendocrine function. In addition, leptin has recently been shown to affect reproductive function in rodents and humans. The study of leptin and its effectors in the hypothalamus may provide important insights with respect to the interplay of several hypothalamic neuropeptides in regulating feeding as well as the interaction of genetics and environment in the regulation of energy homeostasis. In this review we summarise the action of leptin in the regulation of food intake and highlight a working model of the effects of environmental factors on the leptin system.

• Journal of the Korea Computer Industry Society
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• v.6 no.5
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• pp.675-686
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• 2005

This paper proposes a new method of mathematically modeling and computer simulating television ghosts wherein television signals that have undergone multipath fading are generated without using approximations by considering the attenuation, time delay, phase, and timing jitter between consecutive frames. Conventional methods used polynomial interpolation or complex arithmetic to take into account the ghost phase, but our method uses only real arithmetic by employing the Hilbert transform and also reduces the computation time using the FFT (fast Fourier transform) algorithm. Furthermore, it is also possible to observe the transmit waveforms in both RF and IF ranges. Various ghost patterns generated in software provide for essential data required for the development of ghost canceling algorithms, and are deemed to be very useful in analyzing the constituent blocks of the transmitter and receiver chain in television broadcasting. The development of ghost cancelers needs to be preceded by the task of mathematically modeling ghosts and their extensive computer simulations.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.347-350
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• 2007

An ECG analysis with activity monitoring for the home care of elderly persons or patients, using wireless sensors technology was design and implemented. The changes in heart rate occur before, during, or following behavior such as posture changes, walking and running. Therefore, it is often very important to record heart rate along with posture and behavior, for continuously monitoring a patient's cardiovascular regulatory system during their daily life activity. The ECG and accelerometer data are continuously recorded with a built-in automatic alarm detection system, for giving early alarm signals even if the patient is unconscious or unaware of cardiac arrhythmias. The hardware allows data to be transmitted wirelessly from on-body sensors to a base station attached to server PC using IEEE802.15.4. If any abnormality un at server then the alarm condition sends to the doctor' PDA (Personal Digital Assistant).