• 한국정보통신학회논문지
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• 제10권7호
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• pp.1307-1311
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• 2006

본 연구에서는 행렬 분해 (Matrix Factorization)를 이용하여 음성 스펙트럼의 부분적 특정을 나타낼 수 있는 새로운 음성 파라마터를 제안한다. 제안된 파라미터는 행렬내의 모든 원소가 음수가 아니라는 조건에서 행렬분해 과정을 거치게 되고 고차원의 데이터가 효과적으로 축소되어 나타남을 알 수 있다. 차원 축소된 데이터는 입력 데이터의 부분적인 특성을 표현한다. 음성 특징 추출 과정에서 일반적으로 사용되는 멜 필터뱅크 (Mel-Filter Bank)의 출력 을 Non-Negative 행렬 분해(NMF:Non-Negative Matrix Factorization) 알고리즘의 입 력으로 사용하고, 알고리즘을 통해 차원 축소된 데이터를 음성인식기의 입력으로 사용하여 멜 주파수 캡스트럼 계수 (MFCC: Mel Frequency Cepstral Coefficient)의 인식결과와 비교해 보았다. 인식결과를 통하여 일반적으로 음성인식기의 성능평가를 위해 사용되는 MFCC에 비하여 제안된 특정 파라미터가 인식 성능이 뛰어남을 알 수 있었다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권14호
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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.

• Asia Marketing Journal
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• 제8권3호
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• pp.141-159
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• 2006

2004년 11월 16일 출시된 세계 최초의 유비쿼터스 음악 서비스인 SK Telecom의 멜론은 국내 음악 산업에서 새로운 비즈니스 모델로 성공을 거두었다. 멜론의 성공 배경에는 차별적인 서비스 특징 뿐만 아니라 기술적 측면과 고객 지향적 측면에서 핵심 역량을 갖추고자 한 노력이 있다. 또한, 경쟁사 대비 비교 우위의 마케팅 믹스 활동도 간과할 수 없다. 본 사례에서는 멜론이 출시되기까지의 과정과 많은 사람들이 아직까지 생소해 하는 온라인 음악 서비스에 대해 소개하고, 성공을 향한 멜론의 노력과 이를 통해 달성된 가시적 성과를 설명하였다. 그리고 지금보다 발전된 성과를 도출시키기 위해서 해결해야 할 전략적 과제를 제시하였다.

• Journal of Information Technology Applications and Management
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• 제30권5호
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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.

• ETRI Journal
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• 제18권1호
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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.

• BMB Reports
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• 제31권4호
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• pp.339-344
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• 1998

The plant flavonoids, including apigenin which is found in especially high concentrations in edible plants, are reported to protect against chronic diseases including several types of cancer. We observed that apigenin inhibited not only the growth of human melanoma cell line SK-MEL 28 but also the telomerase activity. We also noted the telomerase activity inhibition by genistein, a tyrosine kinase inhibitor found in soybean, which suggests that the telomerase activity of SK-MEL 28 cells may be regulated by the protein phosphorylation. Furthermore, we observed that apigenin induced SK-MEL 28 cell apoptosis with p53 upregulation. Taken together, our results indicate that apigenin plays a role as an antimelanoma component in edible plants.

• Toxicological Research
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• 제19권2호
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• pp.147-152
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• 2003

We investigated antitumor activities of the ethanol extract from mushroom Phellinus linteus and Phellinus baumii on mulberry, oak and elm. in vitro test, the ethanol extract of mushroom cultivated on oak of Phellinus linteus showed highest activities about SK-OV-3, HCT15, XF498, SK-MEL-2 and A549. SK-OV-3 cell line showed 100% cytotoxicity in 100 $\mu\textrm{g}$/ml and HCT15 (98.39%), XF498 (89.62%), SK-MEL-2 (84.07%) and A549 (79.92%) cytotoxicity respectively. Also $IC_{50}$ showed 3.99 $\mu\textrm{g}$/ml to SK-OV-3 cell line and HCT15 (4.37 $\mu\textrm{g}$/ml), A549 (5.48 $\mu\textrm{g}$/ml), SK-MEL-2 (6.72 $\mu\textrm{g}$/ml), XF 498 (6.88 $\mu\textrm{g}$/ml). As those results, cultivated oak of Phellinus linteus showed a very low $IC_{50}$ value against SK-OV-3, HCT15, XF498, SK-MEL-2 and A549 cancer cell lines.

• KSBB Journal
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• 제13권6호
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• pp.718-723
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• 1998

The effect of glycyrrhizin on melanoma cells was investigated. DNA fragmentation in cultured melanoma cells was promoted by the addition of glycyrrhizin in a dose dependent manner. Administration(i.m.) of glycyrrhizin to Mel/ret transgenic mice resulted in apoptosis induction, reduction of mitochondrial transmembrane potential in melanoma cells. Decreased B220+ B cells were recovered by the treatment of glycyrrhizin in splenocytes and mesenteric lymph node cells, while Thy-1+ T cells were not influenced. Results suggested that glycyrrhizin acted as an inducer of apoptosis of melanoma cells and an immuno-potentiator via recovered B lymphocyte population in Mel/ret transgenic mice.

• 음성과학
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• 제2권
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• pp.57-66
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• 1997

This paper studies the effects of the method, CMS(Cepstral Mean Subtraction), (which compensates for some of the speech distortion. caused by telephone channels), on the performance of the text-dependent speaker identification system. This system is based on the VQ(Vector Quantization) and HMM(Hidden Markov Model) method and chooses the LPC-Cepstrum and Mel-Cepstrum as the feature vectors extracted from the speech data transmitted through telephone channels. Accordingly, we can compare the correct recognition rates of the speaker identification system between the use of LPC-Cepstrum and Mel-Cepstrum. Finally, from the experiment results table, it is found that the Mel-Cepstrum parameter is proven to be superior to the LPC-Cepstrum and that recognition performance improves by about 10% when compensating for telephone channel using the CMS.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2001년도 춘계 학술대회 논문집
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• pp.148-152
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• 2001

본 논문에서는 중대사고 해석코드인 MELCOR를 이용하여 개발중인 중대사고 훈련용 그래픽 시뮬레이터 MEL-GRS에 대하여 기술하였다. MEL-GRS는 SL-GMS 그래픽 튤과 MELCOR 계산 결과를 적절히 사용하여 중대사고 현상을 실시간으로 디스플레이하는 목적으로 개발되었는데, 기존의 MELCOR 코드에서 불가능했던 다이내믹 시뮬레이션 기능을 가지고 있어 실시간 밸브 및 펌프 조작이 가능하다. 개발된 시스템은 IBM PS Windows 환경에서 작동하며, 울진 3, 4호기를 대상으로 한 TLOFW, LOCA등의 중대사고 시나리오를 사용하여 그 성능을 검증하였다. 개발된 시스템은 차후 발전소 현장의 설치 및 검증을 거쳐 운전원 및 TSC 요원의 중대사고 훈련도구로 활용한 계획이다.