• 제목/요약/키워드: error variances

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The Structural Equation Model of Intention to Discontinue Drinking Highly Caffeinated Beverage of Undergraduate Students

  • Lee, Kyu Eun;Kim, Yunsoo
    • Child Health Nursing Research
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    • 제26권1호
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    • pp.35-46
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    • 2020
  • Purpose: The purpose of this study was to test a model for intention to discontinuation drinking high caffeinated beverages among undergraduate students. This model was based on the Ajzen's theory of planned behavior and Becker's health belief model. Methods: Participants consisted of 201 undergraduate students. Data were collected by questionnaires from March 11 to May 24, 2019. Collected data were analyzed using SPSS/WIN 22.0, AMOS 22.0 program. Results: The assessment of the model indicated an acceptable fit (normed x2=1.65, goodness-of-fit index [GFI]=.83, adjusted GFI=.79, comparative fit index [CFI]=.92, standardized root mean square residual [SRMR]=.05, Tucker-Lewis index [TLI]=.91, normed fit index [NFI]=.87, root mean square error of approximation [RMSEA]=.07). Perceived behavior control, subjective norm, the subjective attitude was found to have a significant direct effect on the intention to discontinuation of drinking a high caffeinated beverage. The variances of this model explained 45.3% of the variance in intention to discontinuation of drinking a high caffeinated beverage. Conclusion: These results suggest that a need to increase awareness of adverse effects and potential risks of high caffeinated beverage consumption in undergraduate students. Besides, the university and government should provide education and campaigns to prevent excessive high-caffeinated beverage consumption.

유한요소법과 최적설계 기법을 이용한 고무 사출 금형 히터 배치 (The Arrangement of Heaters for Rubber Injection Molds using FEM and Optimal Design Method)

  • 김명훈;한정영;최은호;배원병;강성수
    • 한국생산제조학회지
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    • 제20권1호
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    • pp.34-39
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    • 2011
  • Temperature control of a rubber injection mold is important for the dimensional accuracy of product. The main objective of this paper is to optimize the arrangement of heaters by FEM and optimal design method. Firstly, 3-dimensional transient heat transfer analysis was carried out for a square specimen mold. Results of FE analysis are a good agreement with the experimental results, showing about 1.22~7.22% error in temperature distribution. Secondly, we suggested the optimal method about an arrangement of heaters of rubber injection mold by using the optimal design technique. Distances between heater's center and the contact surface of mold, distances between heater's center and symmetric surface were considered as design variables. And the variances between the temperatures of cavity surfaces and their average temperature were used as the objective functions. Applying the optimal solution, the temperature variation was improved about 52.9~88.1 % compared to the existing mold. As a result of sensitivity analysis for design variables, design variables parallel to the direction of the split plane in mold affect the largest on the surface temperature variation in mold cavity.

적응 변환코드를 이용한 영상신호 압축 (An Adaptive Transform Code for Images)

  • 김동윤;이경중;윤형로
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1991년도 추계학술대회
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    • pp.44-47
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    • 1991
  • There exists a transform trellis code that is optimal for stationary Gaussian sources and the squared-error distortion measure at all rates. In this paper, we train an asymptotically optimal version of such a code to obtain one which is matched better to the statistics of real world data. The training algorithm uses the M-algorithm to search the trellis codebook and the LBG-algorithm to update the trellis codebook. To adapt the codebook for the varying input data. we use two gain-adaptive methods. The gain-adaptive scheme 1, which normalizes input block data by its gain factor, is applied to images at rate 0.5 bits/pixel. When each block is encoded at the same rate, the nonstationarity among the block variances leads to a variation in the resulting distortion from one block to another. To alleviate the non-uniformity among the encoded image, we design four clusters from the block power, in which each cluster has its own trellis codebook and different rates. The rate of each cluster is assigned through requiring a constant distortion per-letter. This gain-adaptive scheme 2 produces good visual and measurable quality at low rates.

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칼만추정과 초월함수 사영을 통한 L1 신호간의 거리 Metric에 IES을 적용한 새로운 고장진단 기법 (A New Fault Diagnosis Scheme between L1 Signals Using IES on the Metric Defined via Kalman Filter and Exponential Function Transformation)

  • 김성수
    • 전기학회논문지P
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    • 제64권1호
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    • pp.23-28
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    • 2015
  • Measuring the distances between signals in the signal space is usually determined by obtaining the ideal metric which is not easy to obtain. In this research we have investigated the scheme that measures the distances between the signals constructed with the measured voltage signals connected to electric apparatus using Kalman filter and exponential mapping. The metric is defined on the feature signals obtained via the estimation process of a Kalman filter and the mapping process using the exponential transformation. Diagnosis is on the voltage fluctuations is applied to determining whether the system is in the stable state or not due to the unexpected accidents, such as power overcharge, discharge, outages flow may be the cause of the accident. The decision making scheme evaluated with respect to the effectiveness and the degree of complication with different variances. Two methods, the Hard Limit Threshold Scheme(HLTS) and the Interval Energy Scheme(IES) are proposed and compared. In experiments the IES shows better tolerance to impulse noise than the HLTS.

ATM망에서 퍼지 패턴 추정기를 이용한 신경망 호 수락제어에 관한 연구 (A Study on a neural-Net Based Call admission Control Using Fuzzy Pattern Estimator for ATM Networks)

  • 이진이;이종찬;이종석
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1998년도 추계학술대회 학술발표 논문집
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    • pp.173-179
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    • 1998
  • This paper proposes a new call admission control scheme utilizing an inverse fuzzy vector quantizer(IFVQ) and neural net, which combines benefits of IFVQ and flexibilities of FCM(Fuzzy-C-Menas) arithmatics, to decide whether a requested call that is not trained in learning phase to be connected or not. The system generates the estimated traffic pattern of the cell stream of a new call, using feasible/infeasible patterns in codebook, fuzzy membership values that represent the degree to which each pattern of codebook matches input pattern, and FCM arithmatics. The input to the NN is the vector consisted of traffic parameters which is the means and variances of the number of cells arriving inthe interval. After training(using error back propagation algorithm), when the NN is used for decision making, the decision as to whether to accept or reject a new call depends on whether the output is greater or less then decision threshold(+0.5). This method is a new technique for call admi sion control using the membership values as traffic parameter which declared to CAC at the call set up stage, and is valid for a very general traffic model in which the calls of a stream can belong to an unlimited number of traffic classes. Through the simmulation. it is founded the performance of the suggested method outforms compared to the conventional NN method.

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음성인식에서 주 성분 분석에 의한 차원 저감 (Dimensionality Reduction in Speech Recognition by Principal Component Analysis)

  • 이창영
    • 한국전자통신학회논문지
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    • 제8권9호
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    • pp.1299-1305
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    • 2013
  • 이 논문에서 우리는 MFCC 특징벡터의 차원 저감을 통해 음성 인식에서의 계산량을 줄이는 방법을 조사한다. 특징벡터의 특성분해는 벡터의 성분을 분산의 크기에 따라 배치되도록 선형 변환 시켜준다. 첫 번째 성분은 가장 큰 분산을 가져서 패턴 분류에서 가장 중요한 역할을 한다. 따라서, 분산이 작은 성분들을 제외시키는 차원 저감을 통하여, 계산량을 줄이면서 동시에 음성 인식 성능을 저하시키지 않는 방법을 생각할 수 있다. 실험 결과, MFCC 특징벡터의 성분을 절반 정도로 줄여도 음성인식 오류율에 큰 악영향이 없음이 확인되었다.

입출력 변수에 부가 잡음이 있는 FIR형 시스템 인식을 위한 견실한 추정법에 관한 연구 (Error in Variable FIR Typed System Identification Using Combining Total Least Mean Squares Estimation with Least Mean Squares Estimation)

  • 임준석
    • 한국음향학회지
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    • 제29권2호
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    • pp.97-101
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    • 2010
  • 일반적으로 시스템 인식 방법은 입출력에 잡음이 없거나, 출력에만 잡음이 있는 경우를 주 대상으로 한다. 본 논문은 입력 및 출력이 모두 잡음으로 오염되었을 뿐만 아니라 입력에 비해서 출력에 같거나 더 많은 양의 잡음이 개입된 환경에 노출된 Finite Impulse Response 형태의 시스템을 인식하는 새로운 방법을 제안한다. 이를 위해서 입출력의 잡음 수준이 같을 때 최적인 완전최소자승 기법과 출력에만 잡음이 있을 때 최적인 최소자승 기법을 서로 볼록 결합 (convex combination)하여 앞에서 언급한 것과 같은 좀 더 일반화된 잡음 환경에서도 향상된 결과가 나오도록 하였다. 또 제안한 방법이 다양한 잡음 환경에서 응용 가능함을 모의 실험을 통해서 확인하였다.

방류수질 예측을 위한 AI 모델 적용 및 평가 (Application and evaluation for effluent water quality prediction using artificial intelligence model)

  • 김민철;박영호;유광태;김종락
    • 상하수도학회지
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    • 제38권1호
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    • pp.1-15
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    • 2024
  • Occurrence of process environment changes, such as influent load variances and process condition changes, can reduce treatment efficiency, increasing effluent water quality. In order to prevent exceeding effluent standards, it is necessary to manage effluent water quality based on process operation data including influent and process condition before exceeding occur. Accordingly, the development of the effluent water quality prediction system and the application of technology to wastewater treatment processes are getting attention. Therefore, in this study, through the multi-channel measuring instruments in the bio-reactor and smart multi-item water quality sensors (location in bio-reactor influent/effluent) were installed in The Seonam water recycling center #2 treatment plant series 3, it was collected water quality data centering around COD, T-N. Using the collected data, the artificial intelligence-based effluent quality prediction model was developed, and relative errors were compared with effluent TMS measurement data. Through relative error comparison, the applicability of the artificial intelligence-based effluent water quality prediction model in wastewater treatment process was reviewed.

일배체형에 기초한 연쇄분석의 통계학적 알고리즘 연구 (Statistical Algorithm in Genetic Linkage Based on Haplotypes)

  • 김진흠;강대룡;이윤경;신선미;서일;남정모
    • Journal of Preventive Medicine and Public Health
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    • 제37권4호
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    • pp.366-372
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    • 2004
  • Objectives : This study was conducted to propose a new transmission/disequilibrium test(TDT) to test the linkage between genetic markers and disease-susceptibility genes based on haplotypes. Simulation studies were performed to compare the proposed method with that of Zhao et al. in terms of type I error probability and powers. Methods : We estimated the haplotype frequencies using the expectation-maximization(EM) algorithm with parents genotypes taken from a trio dataset, and then constructed a two-way contingency table containing estimated frequencies to all possible pairs of parents haplotypes. We proposed a score test based on differences between column marginals and their corresponding row marginals. The test also involved a covariance structure of marginal differences and their variances. In simulation, we considered a coalescent model with three genetic markers of biallele to investigate the performance of the proposed test under six different configurations. Results : The haplotype-based TDT statistics, our test and Zhao et al.'s test satisfied a type I error probability, but the TDT test based on single locus showed a conservative trend. As expected, the tests based on haplotypes also had better powers than those based on single locus. Our test and that of Zhao et al. were comparable in powers. Conclusion : We proposed a TDT statistic based on haplotypes and showed through simulations that our test was more powerful than the single locus-based test. We will extend our method to multiplex data with affected and/or unaffected sibling(s) or simplex data having only one parent s genotype.

새로운 동적인간신뢰도 방법론과 적용 (A New Dynamic HRA Method and Its Application)

  • Jae, Moo-Sung;Park, Chan-Kue
    • Nuclear Engineering and Technology
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    • 제27권3호
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    • pp.292-300
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    • 1995
  • 이 논문은 새로운 동적 인간신뢰도 분석방법을 제시하였고, 사고관리 방안의 수행시 인간오류확률의 계산에 이 방법을 적용하였다. 기존의 다른 방법과 비교하기 위하여 PSA의 HRA수행시 가장 많이 사용되는 THERP, HCR, 및 SLIM-MAUD 방법론들의 특징을 논의하였다. 정전사고시 공동범람시키는 방안을 예제로 사용하였다. 이 방법은 Requirement와 Achievement의 연관개념에 기초하고 있다. Achievement 변수의 불확정성은 MAAP 전산코드와 Latin Hypercube Sampling 방법을 이용하여 결정하였고 Requirement 변수값은 운전원과의 면담을 통하여 얻었다. 이렇게 얻어진 변수들의 분포를 가지고 여러가지 시간값의 평균과 분산에 대하여 인간오류 확률값을 계산하였다. 이 방법은 매우 유연하여 사고관리 전략수행과 관련한 행위를 포함한 어떤 종류의 운전원 행위에도 적용가능 함을 보여주었다.

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