The game of Go is an oriental strategic board game originated from China at least more than 2,500 years ago. The Monte-Carlo Tree Search (MCTS) algorithm in Go is a method that uses a large number of simulations to approximately estimate the winning rate of candidate moves by sampling the game. The two computer Go programs called Crazy Stone and Mogo defeated human Go professionals on the 9⨯9 board in 2006. Prior to our implementing MCTS into computer Go, we tried to find out the best move sequence in playing Tic-Tac-Toe game as a test bed. The experimental results revealed that the first player should play the center to ensure the highest winning rate, and the game result becomes a draw if two players do their best.

Oral squamous cell carcinoma (OSCC) has been a focus of cancer prevention studies due to the fact that it occurs by a multistep process and that a precancerous lesion in the oral mucosa is easily accessible. The present study was aimed at developing an optical detection system using autofluorescence spectrum measurements for the early detection of oral cancer. The optical detection system was designed to use an excitation wavelength of 337 nm emanating from a Xenon lamp. Precancerous and cancerous lesions were created in the hamster buccal pouch by treatment with 7,12-dimethylbenz[a]anthracene (DMBA). Four groups of five hamsters each were used in this experiment. The right buccal pouch was treated with 0.5% DMBA to induce carcinogenesis while the left buccal pouch was treated with mineral oil as a control. The autofluorescence of both buccal pouches was measured weekly. A difference in the excitation pattern between the normal and the carcinogen-treated tissue was noticed after three weeks. Specifically, the intensity of the autofluorescence spectrum in the DMBA-treated buccal pouch was increased at wavelengths between 400 and 450 nm. The results of the autofluorescence measurements were compared to histological findings and show that the intensity of the autofluorescence increased along with the stage of epithelial dysplasia. Based on the fact that one of the autofluorophores in this tissue is NADH, we measured the fluorescence at the 450-nm NADH wavelength to conclude that the increased autofluorescence in the dysplastic areas may be caused by NADH. Based on these data, we suggest that autofluorescence optical methods are a useful tool for the early detection of oral cancer.

to malignant transformation. Oral leukoplakia is a common premalignant lesion in oral mucosa and the incidence of cancer progression into SCC has been reported to be 0~43%. The genetic alterations of oncogenes, tumor suppressor genes and DNA repair genes occur during carcinogenesis. In order to evaluate the role of epithelial cells in the early stage of carcinogenesis, we analyzed the alterations of genetic heterogeneity in epithelial cells of oral leukoplakia samples, using Laser capture microdissection(LCM). The incidence rate of microsatellite instability(MSI) and loss of heterozygosity(LOH) were analysed from the DNA of epithelial cells from 16 leukoplakia samples using adjacent fibroblasts as a normal control. In this study, LOH was found in epithelial cells of all 16 cases of leukoplakias while MSI has been observed in 3 cases. Interestingly, the fibroblasts showed LOH and MSI in some cases, which was confirmed by DNA sequencing. Taken together, this study showed that leukoplakia has multiple genetic alterations in fibroblasts as well as in epithelial cells, suggesting that interaction between epithelial cells and fibroblasts might be involved in the early step of carcinogenesis.

고대 중국에서 기원된 바둑은 인공지능 분야에서 가장 어려운 도전 중의 하나로 간주된다. 지난 수년에 걸쳐 MCTS를 기반으로 하는 정상급 컴퓨터바둑 프로그램이 놀랍게도 접바둑에서 프로기사를 물리쳤다. MCTS는 게임이 끝날 때까지 일련의 무작위 유효착수를 시뮬레이션 하 는 접근법이며, 기존의 지식기반 접근법을 대체했다. 저자는 MCTS의 변형인 UCT 알고리즘을 삼목 게임에 적용하여 최선의 첫 수를 찾고자 했으며, 순수 MCTS의 결과와 비교를 했다. 아울 러 UCB 이해를 위한 다중슬롯머신 문제를 풀기 위해 엡실론-탐욕 알고리즘과 UCB 알고리즘 을 소개 및 성능을 비교하였다.