• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.190-194
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• 2008

This paper presents a speaker identification technique which is one of the basic techniques of the ubiquitous robot companion. Though the conventional mel-frequency cepstral coefficients guarantee high performance of speaker identification in clean condition, the performance is degraded dramatically in noise condition. To overcome this problem, we employed the relative autocorrelation sequence mel-frequency cepstral coefficient which is one of the noise robust features. However, there are two problems in relative autocorrelation sequence mel-frequency cepstral coefficient: 1) the limited information problem. 2) the residual noise problem. In this paper, to deal with these drawbacks, we propose a multi-streaming method for the limited information problem and a hybrid method for the residual noise problem. To evaluate proposed methods, noisy speech is used in which air conditioner noise, classic music, and vacuum noise are artificially added. Through experiments, proposed methods provide better performance of speaker identification than the conventional methods.

• Biomolecules & Therapeutics
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• v.22 no.3
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• pp.207-212
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• 2014

Skin hyperpigmentation is one of the most common skin disorders caused by abnormal melanogenesis. The mechanism and key factors at play are not fully understood. Previous reports have indicated that cystamine (CTM) inhibits melanin synthesis, though its molecular mechanism in melanogenesis remains unclear. In the present study, we investigated the effect of CTM on melanin production using ELISA reader and the expression of proteins involved in melanogenesis by Western blotting, and examined the involvement of transglutaminase-2 (Tgase-2) in SK-MEL-2 human melanoma cells by gene silencing. In the results, CTM dose-dependently suppressed melanin production and dendrite extension in a-MSH-induced melanogenesis of SK-MEL-2 human melanoma cells. CTM also suppressed a-MSH-induced chemotactic migration as well as the expressions of melanogenesis factors TRP-1, TRP-2 and MITF in a-MSH-treated SK-MEL-2 cells. Meanwhile, gene silencing of Tgase-2 suppressed dendrite extension and the expressions of TRP-1 and TRP-2 in a-MSH-treated SK-MEL-2 cells. Overall, these findings suggested that CTM suppresses a-MSH-induced melanogenesis via Tgase-2 inhibition and that therefore, Tgase-2 might be a new target in hyperpigmentation disorder therapy.

• BMB Reports
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• v.45 no.2
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• pp.126-131
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• 2012

We have previously identified a DNA silent region located downstream of the 3'-end of the ${\beta}^{major}$ globin gene (designated B1-559) that contains a B1 retrotransposon, consensus binding sites for erythroid specific transcription factors and shares the capacity to act as promoter in hematopoietic cells interacting with ${\beta}$-globin gene LCR sequences in vitro. In this study, we have cloned four new non-polyA RNA transcripts being detected upon blockade of murine erythroleukemia (MEL) cell differentiation to erythroid maturation by methylation inhibitors and demonstrated that two of them share high structural homology with sequences of B1 element found within the B1-559 region. Although it is not clear yet whether and how these RNAs interfere with induction of erythroid maturation, these data provide evidence for the first time showing that methylation inhibitors can activate silent repetitive DNA sequences in MEL cells and may have implications in cancer chemotherapy using demethylating drugs as antineoplastic agents.

• ETRI Journal
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• v.18 no.1
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• pp.29-41
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• 1996

This paper describes a method to select a suitable feature for speech recognition using information theoretic measure. Conventional speech recognition systems heuristically choose a portion of frequency components, cepstrum, mel-cepstrum, energy, and their time differences of speech waveforms as their speech features. However, these systems never have good performance if the selected features are not suitable for speech recognition. Since the recognition rate is the only performance measure of speech recognition system, it is hard to judge how suitable the selected feature is. To solve this problem, it is essential to analyze the feature itself, and measure how good the feature itself is. Good speech features should contain all of the class-related information and as small amount of the class-irrelevant variation as possible. In this paper, we suggest a method to measure the class-related information and the amount of the class-irrelevant variation based on the Shannon's information theory. Using this method, we compare the mel-scaled FFT, cepstrum, mel-cepstrum, and wavelet features of the TIMIT speech data. The result shows that, among these features, the mel-scaled FFT is the best feature for speech recognition based on the proposed measure.

• YAKHAK HOEJI
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• v.47 no.6
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• pp.345-351
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• 2003

Heptaplatin, cis-Malonato[(4R,5R)-4,5-bis(aminomethyl)-2-isopropyl-1,3-dioxolane]platinum(II), is a novel platinum-based antitumor agent with clinical potential against human stomach cancer and the 3rd generation of the cisplatin. This study was performed to study how cisplain, heptaplatin and sunpla which is a mixture of heptaplatin and mannitol (w: w=l : 2) affect cell viability of SK-MEL-28 human melanoma cell line. Heptaplatin ($IC_{50}$/; 95.35 $\mu$M) and sunpla ($IC_{50}$/; 10.95 11M) were less effect than cisplatin (IC $_{50}$; 10.92 $\mu$M) on the SK-MEL-28 cells. By cell cycle analysis using flow cytometry, it was identified that the cells were arrested at G2/M phase by cisplatin, heptaplatin and sunpla, and percentage of cell death group was increased according to increasing of time and concentration. These results suggest that cisplatin, heptaplatin and sunpla are a novel anticancer agent against human melanoma cell.l.

• YAKHAK HOEJI
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• v.48 no.2
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• pp.147-152
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• 2004

A wide variety of cancer chemotherapeutic agents have been shown to induce programmed cell death (PCD, APOPTOSIS) in various tumor cell lines in vitro. cis-Malonato [(4R,5R)-4,5-bis(aminomethyl)-2-isoprpopyl-1,3-dioxolane] platinum(II) (heptaplatin), which is a new drug approved by KFDA in 1999, in a novel platinum-based antitumor agent with clinical potential against stomach cancer and the 3rd generation of the cisplatin. This study was performed to know how heptaplatin and cisplatin and sunpla (mixture of heptaplatin and mannitol) affect on SK-MEL-28 cell line, and how they induce the apoptosis. At EM analysis, the morphology of the cell was changed by treatment of the cisplatin, heptaplatin and sunpla. Apoptotic body formed around plasma membrane, and chromatin condensation represented in nucleus. This phenomenon is one of the characteristic of the apoptosis. The DNA of SK-MEL-28 cell line truncated by cisplatin and sunpla treatment was identified on 2% agarose gel electrophoresis. TUNEL assay was performed to know whether SK-MEL-28 cell die as apoptosis or necrosis by cisplatin, heptaplatin and sunpla. At this result, fluorescence intensity increased according to increase of time and concentration. Therefore, it was identified that cislatin, heptaplatin and sunpla induced apoptosis. Fas expressed on SK-MEL-28 cell membrane by cisplatin, heptaplatin and sunpla was identified by using flow cytometer and the expression of bcl-2(anti-apoptotic gene) decreased according to increase of concentration of the cisplatin, heptaplatin and sunpla. Cisplatin, heptaplatin and sunpla induced apoptosis against SK-MEL-28 cell line, and the apoptotic mechanism was identified as Fas-mediated apoptosis and decreased bcl-2 expression.

• Journal of Life Science
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• v.20 no.5
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• pp.655-661
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• 2010

To elucidate the mechanism underlying the suppressive regulation of hST8Sia I expression in retinoic acid (RA)-induced SK-MEL-2 cells, we characterized the promoter region of the hST8Sia I gene. Functional analysis of the 5‘-flanking region of the hST8Sia I gene by the transient expression method showed that the -1146 to -646 region, which contains putative binding sites for transcription factors c-Ets-1, CREB, AP-1 and NF-kB, functions as the RA-repressive promoter in SK-MEL-2 cells. Site-directed mutagenesis and ChIP analyses indicated that the NF-kB binding site at -731 to -722 is crucial for the RA-induced repression of hST8Sia I in SK-MEL-2 cells. In addition, the transcriptional activity of hST8Sia I suppressed by RA in SK-MEL-2 cells was strongly inhibited by extracellular signal-regulated protein kinase (ERK) inhibitor U0126 and protein kinase C (PKC) inhibitor GO6976, as determined by RT-PCR and luciferase assay of hST8Sia I promoter containing the -1146 to -646 regions. These results suggest that RA markedly modulates transcriptional regulation of hST8Sia I gene expression through the PKC/ERK signal pathway in SK-MEL-2 cells.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.6061-6066
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• 2015

Methotrexate (Mtx), used for its anticancer and immunsuppresive properties, is known to be a nephrotoxic agent. We aimed to investigate the effects of lycopene (Lyc) alone or combined with melatonin (Mel) on Mtxinduced nephrotoxicity since both of these agents have antioxidant and anti-inflammatory effects. Nephrotoxicity was induced by intraperitoneal administration of methotrexate at a dose of 20 mg/kg. Treatment both with Lyc alone and Lyc combined with Mel provided significant reduction in tumor necrosis factor-alpha, interleukin 1-beta and ceruloplasmin levels in Mtx administered rats. Hovewer, Lyc combined with Mel provided a significant reduction also in NO levels. Hstopathological examination showed that there was an obvious improvement in the degenerative changes compared to Mtx administrated group with the Lyc combined Mel group giving best protection. In conclusion Lyc alone and combined with Mel provided significant improvement against renal damage caused by Mtx, preseumably via antioxidant and anti-inflammatory activities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.1
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• pp.160-168
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• 1995

Desmutagenicities against 2-amino-1-methyl-6-phenylimidazo[4, 5-b] pyridine(PhIP) and 2-amino-3, 8-dimethylimidazo[4, 5-f]quinoxaline(MelQx) of tea extracts (steamed green tea, roasted green tea, oolong tea and black tea) were investigated. All the fractions obtained from tea extracts showed strong desmutagenic activity against PhIP and MeIQx toward S. typhimurium TA 98 in the presence of the S-9 mix. The crude catechin fraction exhibited the strongest desmutagenic activity. Among these tea extracts, black tea especially exhibited the strongest desmutagenic activity and the activity was 70.9~91.0% against PhIP and 92.2~98.8% against MelQx at a concentration(0.5~1.0mg/plate) for drinking. The activity of authentic catechins of (-)-EGC, (-)-EGCg, (-)-ECg and (-)-EC were 79.5%, 60.2%, 46.1% and 43.5% against PhIP, and were 52.3%, 11.6%, 8.2% and 22.1% against MelQx by addition of 1.0mg/plate, respectively. The desmutagenic activity was supposedly due to the (-)-EGCg, (-)-EGC and (-)-EC in tea polyphenols, and the browning materials. The desmutagenicity was stronger when mutagens were preincubated with S-9 mix after reaciton with black tea extracts than when preincubated with them after reaction with S-9 mix. The desmutagenicity of tea extracts was rather expressed by reacting directly with mutagens than by deactivating the activated forms of mutagens.

• Journal of Information Technology Applications and Management
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• v.30 no.5
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• pp.1-19
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• 2023

This study examines Korean users' attitudes and emotions toward Melon and Spotify, which lead the music streaming market. We used Text Mining, Semantic Network Analysis, TF-IDF, Centrality, CONCOR, and Word2Vec analysis. As a result of the study, MelOn was used in a user's daily life. Based on Melon's advantages of providing various contents, the advantage is judged to have considerable competitiveness beyond the limits of the streaming app. However, the MelOn users had negative emotions such as anger, repulsion, and pressure. On the contrary, in the case of Spotify, users were highly interested in the music content. In particular, interest in foreign music was high, and users were also interested in stock investment. In addition, positive emotions such as interest and pleasure were higher than MelOn users, which could be interpreted as providing attractive services to Korean users. While previous studies have mainly focused on technical or personal factors, this study focuses on consumer reactions (online reviews) according to corporate strategies, and this point is the differentiation from others.