• The Korean Journal of Malacology
• /
• v.26 no.4
• /
• pp.255-260
• /
• 2010

This study was conducted to investigate protocol standardization for spermatozoa cryopreservation of the Scapharca broughtonii (Schrenck). Among the freezing rates, freezing at a height of 2 cm above liquid nitrogen surface for 5 minute gave higher activity and survival rate. Among the various diluents, Ringer's solution was the best for S. broughtonii sperm cryopreservation. The suitability of cryoprotectants dimethylsulfoxide (DMSO), dimethylacetamide (DMA), glycerol and methanol were tested against three freezing rates. DMSO gave significantly higher activity and survival rates than others.

• Journal of Aquaculture
• /
• v.19 no.4
• /
• pp.236-241
• /
• 2006

Seasonal variation of the infection by three species of symbiotic copepods in clam, Tresus keenae was investigated in south coast of Korea. The prevalence and abundance of three symbiotic copepods showed seasonal variation with a peak in winter. Reproduction of the copepods occurs from early autumn to spring as indicated by higher ratio of gravid copepods. The frequency distribution of Lichomolgus inflatus, Pseudomyicola spinosus and Anthessius progectus in their host population could be fitted with negative binominal distribution. Results from the present study suggest that seasonal fluctuation in prevalence, relative density and mean intensity is related to temperature and life history of the symbiotic copepods.

• Proceedings of the KIEE Conference
• /
• 2008.10b
• /
• pp.68-70
• /
• 2008

Since the beginning of the 21st century, the emergence of innovative technologies made further advances in minimal access surgery possible. Robotic surgery and telepresence surgery effectively addressed the limitations of laparoscopic procedures, thus revolutionizing minimal access surgery. Surgical robots provide surgeons with to technologically advanced vision and hand skills. As a result, such systems are expected to revolutionize the field of surgery. In that time, much progress has been made in integrating robotic technologies with surgical instrumentation. However, robotic surgery will not only require special training, but it will also change the existing surgical training pattern and reshape the learning curve by offering new solutions, such as robotic surgical simulators and robotic telementoring. This article provides an introduction to medical robotic technologies, develops a possible classification, reviews the evolution of a surgical robot, and discusses future prospects for innovation. In the future, surgical robots should be smaller, less expensive, easier to operate, and should seamlessly integrate emerging technologies from a number of different fields. We believe that, in the near future as robotic technology continues to develop, almost all kinds of endoscopic surgery will be performed by this technology.

• Korean Journal of Human Ecology
• /
• v.14 no.4
• /
• pp.505-519
• /
• 2005

The purpose of the study is to survey on the parental education practiced in kindergarten context and to investigate the need for the parental education of personnel involved. To satisfy these purposes, 179 mothers and 175 fathers with 3 to 5 year olds, and 186 teachers and 59 directors of the kindergarten business were asked to complete a survey questionnaire designed for the study. The results indicate that for the present, most kindergartens in Daejeon have practiced parental education programs including weekly letters and parents' day. New subject- appropriate programs development is needed, though. The three groups of subjects had differing views on the need for parental education. The views tend to differ by socio-economic status of each group member, thus indicating the importance of developing and adopting various parental education programs and methods according to the difference. It will contribute to maximizing the effect of the education. Data collected in the study were expected to be used for the development of effective parental education programs.

• Korean Journal of Human Ecology
• /
• v.15 no.6
• /
• pp.937-949
• /
• 2006

The purpose of the study was to explore the effect of the extensive program using the story telling on young children's linguistic creativity. 20 five-year-olds and 18 four-year-olds from a day care center were selected for this study. After performing pre-test, they were divided into control and experimental group. Children's linguistic creativity was measured using 'Imagining Red' of 'Korean Comprehensive Creativity Test for Young Children' standardized by Chun(2000). 6 books were selected for the extensive program for the promotion of children's linguistic creativity was carried out to experimental group for three weeks. After three weeks, post-test was performed on experimental and control group. The results indicate that the extensive program using the storytelling had an effect on promoting young children's linguistic creativity including the sub-elements such as fluency, flexibility, and originality. As the results of experiencing the extensive program related to storytelling, the linguistic creativity of 5 year olds improved more than that of 4 year aids and that of girls improved more than that of boys. For the developing children's linguistic creativity, various extensive activities need to be programmed.

• Atmosphere
• /
• v.17 no.3
• /
• pp.255-268
• /
• 2007

This study generated and evaluated the high resolution (5 km) gridded data of monthly mean, maximum and minimum temperature from 2002 to 2005 over South Korea using a modified PRISM(Parameter-elevation Regressions on Independent Slopes Model: K-PRISM) developed by Daly et al. (2003). The performance of K-PRISM was evaluated by qualitative and quantitative ways using the observations and gridded data derived by inverse distance weighting (IDW) and hypsometric methods (HYPS). For the generation of high resolution gridded data, geographic informations over South Korea, such as the digital elevation, topographic facet and coastal proximity, are derived from the 1 km digital elevation data. The spatial patterns of temperature derived by K-PRISM were more closely linked to topography and coastal proximity than those by IDW. The K-PRISM performed much better than IDW for all months and temperatures, but it was equal to or slightly better than the HYPS. And the performances of K-PRISM were better in the minimum and mean temperature (winter) than the in maximum temperature (summer).

• Proceedings of the Korean Statistical Society Conference
• /
• 2004.11a
• /
• pp.195-198
• /
• 2004

One Important problem in a cancer microarray study is to identify a set of genes from which a molecular prognostic indicator can be developed. In parallel with this problem is to validate the chosen set of genes. We develop in this note a K-fold cross validation procedure by combining a 'pre-validation' technique and a bootstrap resampling procedure in the Cox regression . The pre-validation technique predicts the microarray predictor of a case without having seen the true class level of the case. It was suggested by Tibshirani and Efron (2002) to avoid the possible over-fitting in the regression in which a microarray based predictor is employed. The bootstrap resampling procedure for the Cox regression was proposed by Sauerbrei and Schumacher (1992) as a means of overcoming the instability of a stepwise selection procedure. We apply this K-fold cross validation to the microarray data of 92 gastric cancers of which the experiment was conducted at Cancer Metastasis Research Center, Yonsei University. We also share some of our experience on the 'false positive' result due to the information leak.

• Proceedings of the Korean Society for Bioinformatics Conference
• /
• 2003.10a
• /
• pp.101-106
• /
• 2003

In this paper, we propose using Hotelling's T2 statistic for the detection of a set of a set of differentially expressed (DE) genes in colorectal cancer based on its gene expression level in tumor tissues compared with those in normal tissues and to evaluate its predictivity which let us rank genes for the development of biomarkers for population screening of colorectal cancer. We compared the prediction rate based on the DE genes selected by Hotelling's T2 statistic and univariate t statistic using various prediction methods, a regulized discrimination analysis and a support vector machine. The result shows that the prediction rate based on T2 is better than that of univatiate t. This implies that it may not be sufficient to look at each gene in a separate universe and that evaluating combinations of genes reveals interesting information that will not be discovered otherwise.

• Proceedings of the Korean Society for Bioinformatics Conference
• /
• 2003.10a
• /
• pp.139-146
• /
• 2003

암의 조기 발견 및 예후 예측을 위하여 마이크로어레이 데이터를 이용할 수 있다. 하지만 이를 분석하기 위해서는 40${\mu}g$ 이상의 RNA 샘플이 필요한데, 실제 임상 시료를 사용하는 경우 요구되는 충분한 양을 얻기가 어려운 단점이 있다. 따라서 소량의 RNA 샘플을 채취한 후 PCR 증폭 과정을 통하여 요구되는 양의 샘플을 얻을 수 있는 RNA 증폭 방법이 시도되고 있고, 이를 마이크로어레이 실험에 이용하기 위해서는 증폭 전후의 유사성이 보장되어야 한다. 본 논문에서는 증폭 RNA와 전체 RNA의 유사성을 비교하기 위한 새로운 방법으로 엔트로피 기반의 방법을 제시한다. 아울러 다양한 조건에 따라서 엔트로피값을 측정하여 세포주와 조직에서 엔트로피 값이 어떻게 사용될 수 있는지 체계적인 분석을 하였다.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.1
• /
• pp.116-122
• /
• 2007

An efficient enzyme system for the synthesis of L-tyrosine was developed using a fed-batch reactor with continuous feeding of phenol, pyruvate, and ammonia. A thermo- and chemostable tyrosine phenol-lyase from Symbiobacterium toebii was employed as the biocatalyst in this work. The enzyme was produced using a constitutive expression system in Escherichia coli BL21, and prepared as a soluble extract by rapid clarification, involving treatment with 40% methanol in the presence of excess ammonium chloride. The stability of the enzyme was maintained for at least 18 h under the synthesis conditions, including 75 mM phenol at pH 8.5 and $40^{\circ}C$. The fed-batch system (working volume, 0.51) containing 1.0 kU of the enzyme preparation was continuously fed with two substrate preparations: one containing 2.2 M phenol and 2.4 M sodium pyruvate, and the other containing 0.4 mM pyridoxal-5-phosphate and 4M ammonium chloride (pH 8.5). The system produced 130g/I of L-tyrosine within 30h, mostly as precipitated particles, upon continuous feeding of the substrates for 22 h. The maximum conversion yield of L-tyrosine was 94% on the basis of the supplied phenol.