• 한국정보전자통신기술학회논문지
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• 제17권2호
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• pp.113-120
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• 2024

개체군 희소 지표는 인공 신경망을 구성하고 있는 내부 레이어의 동작을 뉴런의 관점에서 관찰할 수 있기 때문에 블랙박스로 불리는 인공 신경망 내부의 동작을 설명하기 위하여 활용될 수 있다. 최근의 연구에서는 개체군 희소 지표를 두 종류의 컨벌루션 신경망 모델 분석에 적용하여, 레이어의 층이 깊어질수록 지표 값이 비례하여 증가하는 것이 관찰되었음을 보고하였다. 또한, 영상 분류를 위한 컨벌루션 신경망 모델에서 개체군 희소성 지표와 성능이 양의 상관성을 보인다는 연구도 있다. 본 연구에서는 적대적 예제가 컨벌루션 신경망에 적용되었을 때 신경망 내부에서 어떠한 동작이 수행되는지에 대하여 관찰하였다. 이를 위하여 적대적 예제를 입력으로 하는 컨벌루션 신경망의 개체군 희소 지표를 구한 다음, 컨벌루션 신경망의 성능과의 상관성을 비교하였다. 실험의 결과로부터 사전에 5%의 정확도를 갖도록 변형된 적대적 예제들에 대하여 온건한 데이터를 적용한 경우와 유사한 패턴의 양의 상관성을 갖는 것을 확인할 수 있었다. 이 실험결과는 적대적 예제와 온건한 데이터에 대한 각각의 개체군 희소성 지표 값들이 거시적인 관점에서 차이가 없다는 것을 의미하며 적대적 예제가 뉴런의 활성화 측면에서부터 적대적으로 동작한다는 것을 의미한다.

• Journal of Nutrition and Health
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• 제34권4호
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• pp.440-448
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• 2001

As diverse physiological functions of taurine have been reported, taurine-containing health drinks and products are marketed worldwide for the treatment of various conditions such as improvements of liver, heart and circulatory functions or as an aid to athletic performance. Although animal studies have shown that taurine is fairly safe when supplemented in the diet for an extended period, the effective dose range of taurine for dietary supplements is in controversy. Reports on dietary taurine intakes have been sparse, and would serve as a guideline for determining an appropriate taurine dosage. The present study was aimed to estimate dietary intake level of taurine using the taurine content database of commonly used food stuffs established recently in our laboratory, and also to evaluate plasma concentration and urinary excretion of taurine in adolescents and adults residing in Seoul area. Dietary taurine intakes of the subjects were 219$\pm$16.9mg/day for 16-19 years old(n=123), 177$\pm$18.1mg/day for adults older than 20 years old(n=123). Male subjects(n=115) consumed 216$\pm$21.1mg of taurine/day, while female subjects(n=131) consumed 181$\pm$14.3mg of taurine/day(p<0.05). The level of dietary taurine intake was positively correlated with the levels of dietary intakes of energy, carbohydrate, total lipids, cholesterol, vitamin A, vitamin B$_1$, niacin, vitamin C, calcium, phosphorous, sodium and potassium at p<0.01, and with dietary intakes of iron and animal lipids at p<0.05, respectively. Plasma taurine concentration of subjects were 135$\pm$5.9$\mu$mol/L, which is considered to be within a normal range for healthy subjects. The subjects excreted 1158$\pm$72.7nmol/ of tarine mg creatinine in their urine, which is approximated as 150-170mg of taurine/24hr urine based on the assumption that 18mg creatinine/kg/day is excreted in the urine of healthy adults, and this would be about 80% of the daily taurine intake observed in the same subjects. Dietary taurine intake level was positively correlated with plasma taurine concentration, as well as with urinary taurine excretion corrected by creatinine excretion at p<0.05. The present study was the first report of taurine intake, and plasma concentration and urinary excretion of taurine in a Korean population so far, and these results would serve as an index for the future study evaluating taurine status in a diverse population within and outside Korea. (Korean J Nutrition 34(4) : 440~448, 2001)

• Journal of Gastric Cancer
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• 제18권3호
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• pp.230-241
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• 2018

Purpose: Enhanced recovery after surgery (ERAS) protocols for gastric cancer patients have shown improved outcomes in Asia. However, data on gastric cancer ERAS (GCERAS) programs in the United States are sparse. The purpose of this study was to compare perioperative outcomes before and after implementation of an GC-ERAS protocol at a National Comprehensive Cancer Center in the United States. Materials and Methods: We reviewed medical records of patients surgically treated for gastric cancer with curative intent from January 2012 to October 2016 and compared the GC-ERAS group (November 1, 2015-October 1, 2016) with the historical control (HC) group (January 1, 2012-October 31, 2015). Propensity score matching was used to adjust for age, sex, number of comorbidities, body mass index, stage of disease, and distal versus total gastrectomy. Results: Of a total of 95 identified patients, matching analysis resulted in 20 and 40 patients in the GC-ERAS and HC groups, respectively. Lower rates of nasogastric tube (35% vs. 100%, P<0.001) and intraabdominal drain placement (25% vs. 85%, P<0.001), faster advancement of diet (P<0.001), and shorter length of hospital stay (5.5 vs. 7.8 days, P=0.01) were observed in the GC-ERAS group than in the HC group. The GC-ERAS group showed a trend toward increased use of minimally invasive surgery (P=0.06). There were similar complication and 30-day readmission rates between the two groups (P=0.57 and P=0.66, respectively). Conclusions: The implementation of a GC-ERAS protocol significantly improved perioperative outcomes in a western cancer center. This finding warrants further prospective investigation.