• 한국산학기술학회논문지
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• 제10권4호
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• pp.811-817
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• 2009

IT 시스템 기반의 네트워크 환경의 급속한 발전은 지속적인 연구방향의 중요한 이슈의 결과이다. 침입시도 탐지는 관심분야의 하나인 것이다. 최근에 다양한 기술을 기반으로 하는 침입시도탐지들이 제안되고 있으나 이러한 기술은 여러 형태의 침입시도의 패턴 중에 한가지 형태 및 시스템에 적용이 가능한 것이다. 또한 새로운 형태 침입시도를 탐지하지 못하고 있다. 그러므로 새로운 형태를 인식하는 침입탐지 관련 기술이 요구되어 지고 있다. 본 연구에서는 퍼지인식도와 비정상 트래픽 분석을 이용한 네트워크 기반의 침입탐지기법(NePID)을 제안한다. 이 제안은 패킷 분석을 통하여 서비스거부공격과 유사한 침입시도를 탐지하는 것이다. 서비스거부공격은 침입시도의 형태를 나타내며 대표적인 공격으로는 syn flooding 공격이 있다 제안한 기법은 syn flooding을 탐지하기 위하여 패킷정보를 수집 및 분석한다. 또한 피지인식도와 비정상 트래픽 분석을 적용하여 판단모듈의 분석 결과를 토대로 기존의 서비스 거부 공격의 탐지 툴과의 비교분석을 하였으며 실험데이터로는 MIT Lincoln 연구실의 IDS 평가데이터 (KDD'99)를 이용하였다. 시뮬레이션 결과 최대평균 positive rate는 97.094% 탐지율과 negative rate는 2.936%을 얻었으며 이 결과치는 KDD'99의 우승자인 Bernard의 결과치와 유사한 수준의 값을 나타내었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(4)
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• pp.21-24
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• 2001

In this paper, we present a fast face detection algorithm by estimating the eye region using neural network. To implement a real time face detection system, it is necessary to reduce search space. We limit the search space just to a few pairs of eye candidates. For the selection of them, we first isolate possible eye regions in the fast and robust way by modified histogram equalization. The eye candidates are paired to form an eye pair and each of the eye pair is estimated how close it is to a true eye pair in two aspects : One is how similar the two eye candidates are in shape and the other is how close each of them is to a true eye image A multi-layer perceptron neural network is used to find the eye candidate region's closeness to the true eye image. Just a few best candidates are then verified by eigenfaces. The experimental results show that this approach is fast and reliable. We achieved 94% detection rate with average 0.1 sec Processing time in Pentium III PC in the experiment on 424 gray scale images from MIT, Yale, and Yonsei databases.

• Clinical and Experimental Reproductive Medicine
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• 제19권1호
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• pp.57-64
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• 1992

The present study was undertaken to clarify the role of TEST-Yolk Buffer(TYB) as a factor for the improvement of human sperm fertility potential. We examined the effects of low temperature capacitation using TYB on sperm motility (%), motility pattern, normal morphology, true acrosome reaction, sperm penetration assay and human in vitro fertilization. Comparing the TYB method and swim-up method, the sperm motility(%) of selected sperm was not significantly different, but statistically significant differences were found in curvilinear velocity, linearity, lateral head displacement, normal morphology(%) and true acrosome reaction(%)(p<0.05). Results obtained from the sperm penetration assay demonstrated that the penetration index and penetration rate were increased significantly(p<0.05) when the spermatozoa were incubated in TYB, as compared with swim-up method. And fertilization of intact human oocytes was more succesful when spermatozoa were pretreated with TYB at $4^{\circ}C$ for 48 hours as compared with swim-up method. Our results show that TYB method have advantages in terms of enhancement of sperm hyperactivation, increased true acrosome reaction, increased ability to penetrate zona-free hamster ova and augmented fertilization of human oocytes, suggesting that TYB is superior in its ability to preserve sperm motility and fertilizing ability.

• Journal of Acupuncture Research
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• 제24권6호
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• pp.187-193
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• 2007

Objectives : The objectives of this study were to investigate the relationship between electrical detection of ear acupuncture points and musculoskeletal pain. Methods : 18 adults who have musculoskeletal pain without trauma factorsparticipated in this study. They answered the questionnaire and their ear acupuncture points were examined with electrical detectors. We analyzed the relationship between electrical detection of ear acupuncture points and musculoskeletal pain with concordance rate and validity. Results : Total concordance rates of the head region was 68.00%(questionnaire) 32.08%(investigation), that of vertebral region was 67.86%, 59.38%, that of both upper limbs was 86.67%, 39.69%, and that of both lower limbs was 50.00%, 23.46%. The true positive rate was 0.704, the true negative rate was 0.492, the false positive rate was 0.508, and the false negative rate was 0.296 in the validity test. In the head, two concordance rates of the temporal and occipital regions were relatively higher than those of the parietal and frontal regions. In the vertebral region, two concordance rates of the cervical and lumbar regions were relatively higher than those of the thoracic and sacrum regions. In the upper limb, two concordance rates of the shoulder and shoulder joints were relatively higher than those of the others. In the lower limb, concordance rates of investigation were relatively low at all areas. The right lower limb was relatively higher than the left in concordance rates of the questionnaire. Conclusions : The results suggest that electrical detection of ear acupuncture points can be used in the diagnosis and treatment of musculoskeletal pain.

• 응용통계연구
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• 제32권4호
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• pp.593-605
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• 2019

ROC 곡선 아래 면적과 ROC 곡면 아래 부피를 이용하여 분류모형의 판별력을 측정하는 통계량인 AUC와 VUS에 관한 많은 연구가 있다. ROC 곡선을 구성하는 FPR과 TPR 모두에 제한을 두는 양방향 부분 AUC는 부분 AUC보다 더 효과적이고 정확하게 제안되었다. ROC 곡면에서도 부분 VUS 뿐만 아니라 세 방향 부분 VUS 통계량이 개발되었다. 본 연구에서는 ROC 곡선의 FPR과 TPR 모두에 제한된 두 개의 절단함수를 이용하여 확률 개념과 적분 표현으로 대안적인 AUC를 제안한다. 또한 이 AUC는 양방향 부분 AUC와 관계가 있음을 알 수 있다. ROC 곡면에서의 세 방향 부분 VUS도 절단함수를 이용하는 VUS와 관련되어 있음을 발견하였다. 그리고 이러한 대안적인 AUC와 VUS는 맨-휘트니 통계량으로 표현되고 추정된다. 정규분포와 확률표본을 기반으로 이들의 모수적인 추정 방법과 비모수적인 추정 방법을 탐색한다.

• Communications for Statistical Applications and Methods
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• 제6권1호
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• pp.293-303
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• 1999

When test outcomes of units are dichotomous and he infection rate is small group testing is more efficient that noe-to-one testing in estimating the true p and classifying units as infected or not. In this paper two-sided hypothesis testing and confidence intervals are derived based on the UMP(uniformly most powerful) unbiased test. The UMP unbiased approach is compared with Thompson's and Bhattacharyya et al.'s approaches by computing the length of confidence intervals and capture probabilities and shown to have a number of desirable properties. Unequal allocation one of advantages of the proposed approach is also mentioned.

• Journal of applied mathematics & informatics
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• 제28권5_6호
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• pp.1409-1418
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• 2010

In this paper, we present a preconditioned iterative method for solving linear systems Ax = b, where A is a Z-matrix. We give some comparison theorems to show that the rate of convergence of the new preconditioned iterative method is faster than the rate of convergence of the previous preconditioned iterative method. Finally, we give one numerical example to show that our results are true.

• International Journal of Reliability and Applications
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• 제2권1호
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• pp.49-56
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• 2001

In this paper we consider empirical Bayes estimation of the hazard rate and survival probabilities with right censored data under the assumption that the hazard function is constant over the period of observation and the prior distribution is gamma. We provide an estimator of the first derivative of the prior moment generating function that converges at each point to the true value in $L_2$ and use it to obtain, easy to compute, asymptotically optimal estimators under the squared error loss function.

• 한국자원식물학회지
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• 제10권2호
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• pp.128-134
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• 1997

This study was conducted to test on the resistance of varieties bred by crossing with Asominori to bacterial leaf blight. Nakdongbyeo and Dongjinbyeo which were susceptible to HB 9011, 8 resistant varieties including Ilmibyeo derived from Asominori and Asominori, Hwangok, 13 varieties including Chukoku 45 which were resistance to HB 9011, HB 9022 and HB 9033 were used to screen their res ponce depending on the various screening methods such as the true resistance, the secondary infection resistance and the disease common field test methods, and the results are as follows: Among 13 varieties tested, 11 varieties including llmibyeo showed tme resistance to HB 9011. Less than 1.0cm of disease lesion were developed on these varieties. Disease lesion was not developed on most of the Asominori lines including Daechongbyeo against IIB9011 and 1lmibyeo was also resistance to HB 9011, on this variety disease lesion area rate was 1.2%, and 7 varieties including Hwajinbyeo showed field resistance to HB 9022. Disease lesion area rate were 19.6% on Nakdongbyeo. 15.6% on Dongjinbyeo, from 3.0% to 2.4% on Asominori lines, and 0.5% on the Asominori when screened at disease common area. Disease was not developed on Keumnambyeo. Significant correlation coefficiences were found between the results from the test methods of the true resistance, the field resistance ancl the field resistance at disease common field tests on Asominori lines, but in some cases, even the varieties on which disease lesions developed, showed field resistance to HB 9022 and HB 9033.

• 응용통계연구
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• 제23권5호
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• pp.943-953
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• 2010

신용평가연구에서 확률변수 스코어와 정상과 부도상태의 모수공간으로 정의된 혼합분포에서 확률밀도함수의 관계식으로 최적분류점을 추정하고 이에 대응하는 오류합의 크기를 비교하는 연구가 정규분포의 가정하에 이루어져있는데 본 연구에서는 비정규분포인 와이블, 로지스틱 그리고 감마분포로 확장하여 가설검정을 이용하는 방법과 전체정확도와 진실율을 최대화하는 방법에 의한 최적분류점을 각각 구하고 최적분류점에 대응하는 제I종과 제II종 오류합의 크기를 비교하여 효율성을 비교 토론한다.