• 대한의용생체공학회:의공학회지
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• 제32권1호
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• pp.25-31
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• 2011

Blood glucose information is important for self regulation in daily life, but the frequency of self test remains to be only 17%(9 tests/month) in Korea, mainly due to pain during blood sampling. The present study tried to validate the clinical efficacy of the forearm as an alternative sampling site with minimized pain. Capillary blood was sampled both on the index finger($G_F$) and the forearm($G_A$), immediately followed by glucose measurements in 531 subjects, 25 who visited the Health Enhancement Center of C University Hospital, then venous blood($G_V$) was sampled for glucose test. The blood glucose concentration measured on the forearm was closer to the venous glucose than on the finger. The mean difference between $G_V$and $G_F$ was only 10 mg/dL well within the internationally accepted error limit. Error grid analyses of $G_F-G_V$, $G_A-G_V$ and $G_A-G_F$ revealed that the number of data points in regions A and B took 100%, 99.8%, and 97.9%, respectively. These results demonstrate the forearm blood glucose test is not only accurate but also clinically valid. Therefore, the forearm blood glucose test can be a useful way of self managing the chronic diabetes with minimized sampling pain.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 추계학술대회
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• pp.465-469
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• 2017

본 논문에서는 스마트폰 적용을 위한 휴먼 바디 추적 방법을 제안한다. 기존 휴먼 바디 추적 방법은 크게 센서 기반 방법과 비전 기반 방법으로 구분된다. 센서 기반 방법은 위치 정보의 누적 오차로 인해 추적 성능이 떨어지는 단점이 있다. 비전 기반 방법은 누적 오차가 없지만 스마트폰 적용을 위한 연산량 감소가 요구되고 있다. 본 논문에서는 스마트폰 적용을 위한 휴먼 바디 추적 방법으로 개선된 HOG 알고리즘을 이용한다. 개선된 HOG 알고리즘은 다운샘플링과 프레임 샘플링을 통해 구현된다. 다운샘플링에는 가우시안 피라미드가 적용되고, 프레임 샘플링에는 uniform sampling이 적용된다. 제안한 알고리즘을 2개 기기, 4개 해상도, 4개 프레임에서 측정하였고, 실시간으로 적용이 가능한 다운샘플링과 프레임 샘플링 파라미터 중에서 가장 검출률이 좋은 값을 도출하였다.

• 융합정보논문지
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• 제12권1호
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• pp.31-38
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• 2022

본 논문은 전문가 독립적 비지도 신경망 학습 기반 다변량 시계열 데이터 분석 모델인 MSCRED(Multi-Scale Convolutional Recurrent Encoder-Decoder)의 실제 현장에서의 적용과 Auto-encoder 기반인 MSCRED 모델의 한계인, 학습 데이터가 오염되지 않아야 된다는 점을 극복하기 위한 학습 데이터 샘플링 기법인 Subset Sampling Validation을 제시한다. 라벨 분류가 되어있는 발전소 장비의 진동 데이터를 이용하여 1) 학습 데이터에 비정상 데이터가 섞여 있는 상황을 재현하고, 이를 학습한 경우 2) 1과 같은 상황에서 Subset Sampling Validation 기법을 통해 학습 데이터에서 비정상 데이터를 제거한 경우의 Anomaly Score를 비교하여 MSCRED와 Subset Sampling Validation 기법을 유효성을 평가한다. 이를 통해 본 논문은 전문가 독립적이며 오류 데이터에 강한 이상 진단 프레임워크를 제시해, 다양한 다변량 시계열 데이터 분야에서의 간결하고 정확한 해결 방법을 제시한다.

• Communications for Statistical Applications and Methods
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• 제21권1호
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• pp.1-9
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• 2014

This paper discusses the problem of estimation of finite population mean in double sampling for stratification. In fact, ratio and product type exponential estimators of population mean are proposed in double sampling for stratification. The biases and mean squared errors of proposed estimators are obtained upto the first degree of approximation. The proposed estimators have been compared with usual unbiased estimator, ratio and product estimators in double sampling for stratification. To judge the performance of the proposed estimators an empirical study has been carried out.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.86-89
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• 2003

To model a numerical problem space under the limitation of available data, we need to extract sparse but key points from the space and to efficiently approximate the space with them. This study proposes a sampling method based on the search process of genetic algorithm and a space modeling method based on least-squares approximation using the summation of Gaussian functions. We conducted simulations to evaluate them for several kinds of problem spaces: DeJong's, Schaffer's, and our original one. We then compared the performance between our sampling method and sampling at regular intervals and that between our modeling method and modeling using a polynomial. The results showed that the error between a problem space and its model was the smallest for the combination of our sampling and modeling methods for many problem spaces when the number of samples was considerably small.

• Journal of the Korean Data and Information Science Society
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• 제15권4호
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• pp.867-877
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• 2004

The sequential sampling inspection method is an extension of the multiple-sampling methods, and its theory is based on the sequential probability ratio test (SPRT) of Wald. In this paper, the characteristics of SPRT for testing the number of defects are approximated by using the estimated excess over the boundaries. The use of the estimated excess shows good performances in estimating the operating characteristic function and the average sample number of SPRT compared to the method by neglecting the excess. It also makes it possible to determine the boundary values which satisfy the desired error probabilities.

• 한국조사연구학회:학술대회논문집
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• 한국조사연구학회 2002년도 추계학술대회 발표논문집
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• pp.255-274
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• 2002

We classify rotation sampling designs into two classes. The first class replaces sample units within the same rotation group while the second class replaces sample units between different rotation groups. The first class is specified by the three-way balanced design which is a multi-level version of previous balanced designs. We introduce an extended generalized composite estimator (EGCE) and derive its variance and mean squared error for each of the two classes of design, cooperating two types of correlations and three types of biases. Unbiased estimators are derived for difference between interview time biases, between recall time biases, and between rotation group biases. Using the variance and mean squared error, since any rotation design belongs to one of the two classes and the EGCE is a most general estimator for rotation design, we evaluate the efficiency of EGCE to simple weighted estimator and the effects of levels, design gaps, and rotation patterns on variance and mean squared error.

• 한국조사연구학회지:조사연구
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• 제1권1호
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• pp.73-108
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• 2000

사이버공간이 독특한 사회적 공간으로 자리잡고 이에 대한 경험적 자료의 필요성이 중대됨에 따라 컴퓨터 통신망을 이용한 사회조사가 늘어나고 있다. 본 연구는 사이버공간이 보여주는 기술적 기능성을 방법론적으로 검토해 봄으로써 온라인 사회조사의 발전가능성을 탐색하고 있다. 온라인 사회조사는 표집틀, 응답자 접촉방식, 질문지 형태 등에 따라 회원 조사, 방문자조사, 전자우편조사, 전자설문조사로 구분될 수 있으며 기존의 조사방법에 비하여 조사비용의 저렴하고 조사의 실행이 용이하다는 특징을 가지고 있다. 그러나 체계적 오차와 관련하여 온라인 사회조사는 표본설계(모집단의 규정, 표집틀 오차, 추출오차), 측정(측정도구의 구성, 시스템의 안정성과 충실성, 비 응답 및 응답오차) 조사윤리의 측면에서 많은 과제를 안고 있다. 이러한 방법론적인 쟁점에 대한 충분한 고려가 이루어질 때 온라인 사회조사는 본격적인 조사연구의 한 방법으로 자리잡을 수 있을 것이다.

• 품질경영학회지
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• 제30권1호
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• pp.74-96
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• 2002

The objectives of this study is to suggest the rectifying sampling inspection plan considering quality cost. Limiting quality level(LQL) plans(also called LTPD plans) and outgoing quality(OQ) plans are considered. The Hald's linear cost model is discussed with and without a beta prior for the distribution of the fraction of nonconforming items in a lot. It is assumed that the sampling inspection is error free. We consider the design of reliability acceptance sampling plan (RASP) for failure rate level qualification at selected confidence level. The lifetime distribution of products is assumed to be exponential. MIL-STD-690C and K C 6032 standards provide this procedures. But these procedures have some questions to apply in the field. The cost of test and confidence level(1-$\beta$ risk) are the problem between supplier and user. So, we suggest that the optimal life test sampling inspection plans using simple linear cost model considering product cost, capability of environment chamber, environmental test cost, and etc. Especially, we consider a reliability of lots that contain some nonconforming items. In this case we assumed that a nonconforming item fail after environmental life test. Finally, we develope the algorithm of the optimal sampling inspection plan based on minimum costs for rectifying inspection and RASP. And computer application programs are developed So, it is shown how the desired sampling plan can be easily found.

• 품질경영학회지
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• 제43권4호
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• pp.471-488
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• 2015

Purpose: Double sampling $T^2$ chart is a useful tool for detecting a relatively small shift in process mean when the process is controlled by multiple variables. This paper finds the optimal design of the double sampling $T^2$ chart in both economical and statistical sense under Weibull failure model. Methods: The expected cost function is mathematically derived using recursive equation approach. The optimal designs are found using a genetic algorithm for numerical examples and compared to those of single sampling $T^2$ chart. Sensitivity analysis is performed to see the parameter effects. Results: The proposed design outperforms the optimal design of the single sampling $T^2$ chart in terms of the expected cost per unit time and Type-I error rate for all the numerical examples considered. Conclusion: Double sampling $T^2$ chart can be designed to satisfy both economic and statistical requirements under Weibull failure model and the resulting design is better than the single sampling counterpart.