• Title/Summary/Keyword: conditional mean model

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Clothing expenditure, and mediation effect of self-efficacy and moderating effect of disability acceptance in the association between dependency on others and happiness among visually impaired people - Moderated mediating model - (시각장애인의 의복비 지출 현황 조사 및 타인 의존도와 행복의 관계에 미치는 자기효능의 매개효과와 장애 수용의 조절효과 검증 - 조절된 매개모형 분석 -)

  • Minsun, Lee;Hae Rim, Park;Ho Jung, Yang
    • The Research Journal of the Costume Culture
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    • v.30 no.6
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    • pp.842-860
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    • 2022
  • There has been growing attention on the well-being of people with disabilities. The purpose of this study was twofold: (1) to investigate the associations between individuals' socio-demographic and psychological characteristics and clothing expenditure, and (2) to examine the moderated mediation effect of self-efficacy and acceptance of disability on the association between dependency on others and happiness among people with visual impairment. This study was based on secondary analysis of data from the second wave of the 6th Panel Survey of Employment for the Disabled collected by the Employment Development Institute. The results of this study showed that average monthly expenditure on clothing was positively associated with self-efficacy, happiness, and acceptance of disability, while being negatively associated with dependency on others. The results also confirmed that self-efficacy mediated the association between dependency on others and happiness. A conditional direct effect of dependency on others on happiness was found, in which negative associations were significant among people with visual impairment who had low and mean levels of acceptance of disability (but not high levels). In addition, there was a significant conditional indirect effect, in which the indirect and negative effect of dependency on others on happiness via self-efficacy was significant for those with low and average levels of acceptance of disability. These findings support the importance of enhancing the independence and acceptance of disability among people with visual impairment, which ultimately contributes to their happiness.

Automatic order selection procedure for count time series models (계수형 시계열 모형을 위한 자동화 차수 선택 알고리즘)

  • Ji, Yunmi;Seong, Byeongchan
    • The Korean Journal of Applied Statistics
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    • v.33 no.2
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    • pp.147-160
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    • 2020
  • In this paper, we study an algorithm that automatically determines the orders of past observations and conditional mean values that play an important role in count time series models. Based on the orders of the ARIMA model, the algorithm constitutes the order candidates group for time series generalized linear models and selects the final model based on information criterion among the combinations of the order candidates group. To evaluate the proposed algorithm, we perform small simulations and empirical analysis according to underlying models and time series as well as compare forecasting performances with the ARIMA model. The results of the comparison confirm that the time series generalized linear model offers better performance than the ARIMA model for the count time series analysis. In addition, the empirical analysis shows better performance in mid and long term forecasting than the ARIMA model.

Assessment of 6-Month Lead Prediction Skill of the GloSea5 Hindcast Experiment (GloSea5 모형의 6개월 장기 기후 예측성 검증)

  • Jung, Myung-Il;Son, Seok-Woo;Choi, Jung;Kang, Hyun-Suk
    • Atmosphere
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    • v.25 no.2
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    • pp.323-337
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    • 2015
  • This study explores the 6-month lead prediction skill of several climate indices that influence on East Asian climate in the GloSea5 hindcast experiment. Such indices include Nino3.4, Indian Ocean Diploe (IOD), Arctic Oscillation (AO), various summer and winter Asian monsoon indices. The model's prediction skill of these indices is evaluated by computing the anomaly correlation coefficient (ACC) and mean squared skill score (MSSS) for ensemble mean values over the period of 1996~2009. In general, climate indices that have low seasonal variability are predicted well. For example, in terms of ACC, Nino3.4 index is predicted well at least 6 months in advance. The IOD index is also well predicted in late summer and autumn. This contrasts with the prediction skill of AO index which shows essentially no skill beyond a few months except in February and August. Both summer and winter Asian monsoon indices are also poorly predicted. An exception is the Western North Pacific Monsoon (WNPM) index that exhibits a prediction skill up to 4- to 6-month lead time. However, when MSSS is considered, most climate indices, except Nino3.4 index, show a negligible prediction skill, indicating that conditional bias is significant in the model. These results are only weakly sensitive to the number of ensemble members.

Estimating Values of Statistical Lives using Choice Experiment Method (선택실험법을 이용한 확률적 인간생명가치의 추정)

  • Shin, Young Chul
    • Environmental and Resource Economics Review
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    • v.16 no.3
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    • pp.683-699
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    • 2007
  • This study applied the choice experiment (CE) method to measure values of statistical lives from multi-attributed mortality risk reduction choices. The four characteristics of mortality risk (i.e. cause of death, voluntariness of mortality risk, timing of death, magnitude of mortality risk reduction) are utilized to design the alternatives of choice sets. The estimation results for the multinomial logit model show that individuals are willing to pay 27,930 won per year for a change from the status quo to a $\frac{1}{100}$ mortality risk reduction for 10 years, 116,773 won per year for mortality risk reduction associated with adults, 97,682 won per year for voluntary mortality risk reduction, 77,234 won per year for involuntary mortality risk reduction. There were several estimates of VSL related to different attributes of mortality risk. The mean VSLs of infant/child/young adult ranged from 1,165 million won to 1,367 million won. The mean VSLs ranged from 1,631 million won to 1,833 million won for adult, and were between 1,128 million won and 1,330 million won for old person.

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Generation of He I 1083 nm Images from SDO/AIA 19.3 and 30.4 nm Images by Deep Learning

  • Son, Jihyeon;Cha, Junghun;Moon, Yong-Jae;Lee, Harim;Park, Eunsu;Shin, Gyungin;Jeong, Hyun-Jin
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.1
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    • pp.41.2-41.2
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    • 2021
  • In this study, we generate He I 1083 nm images from Solar Dynamic Observatory (SDO)/Atmospheric Imaging Assembly (AIA) images using a novel deep learning method (pix2pixHD) based on conditional Generative Adversarial Networks (cGAN). He I 1083 nm images from National Solar Observatory (NSO)/Synoptic Optical Long-term Investigations of the Sun (SOLIS) are used as target data. We make three models: single input SDO/AIA 19.3 nm image for Model I, single input 30.4 nm image for Model II, and double input (19.3 and 30.4 nm) images for Model III. We use data from 2010 October to 2015 July except for June and December for training and the remaining one for test. Major results of our study are as follows. First, the models successfully generate He I 1083 nm images with high correlations. Second, the model with two input images shows better results than those with one input image in terms of metrics such as correlation coefficient (CC) and root mean squared error (RMSE). CC and RMSE between real and AI-generated ones for the model III with 4 by 4 binnings are 0.84 and 11.80, respectively. Third, AI-generated images show well observational features such as active regions, filaments, and coronal holes. This work is meaningful in that our model can produce He I 1083 nm images with higher cadence without data gaps, which would be useful for studying the time evolution of chromosphere and coronal holes.

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The Assessing Comparative Study for Statistical Process Control of Software Reliability Model Based on Musa-Okumo and Power-law Type (Musa-Okumoto와 Power-law형 NHPP 소프트웨어 신뢰모형에 관한 통계적 공정관리 접근방법 비교연구)

  • Kim, Hee-Cheul
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.8 no.6
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    • pp.483-490
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    • 2015
  • There are many software reliability models that are based on the times of occurrences of errors in the debugging of software. It is shown that it is possible to do likelihood inference for software reliability models based on finite failure model and non-homogeneous Poisson Processes (NHPP). For someone making a decision about when to market software, the conditional failure rate is an important variables. The infinite failure model are used in a wide variety of practical situations. Their use in characterization problems, detection of outlier, linear estimation, study of system reliability, life-testing, survival analysis, data compression and many other fields can be seen from the many study. Statistical process control (SPC) can monitor the forecasting of software failure and thereby contribute significantly to the improvement of software reliability. Control charts are widely used for software process control in the software industry. In this paper, proposed a control mechanism based on NHPP using mean value function of Musa-Okumo and Power law type property.

Evaluation of the Influence of Shear Strength Correction through a Comparative Study of Nonlinear Site Response Models (비선형 지반구성모델의 비교를 통한 전단강도 보정이 부지응답해석에 미치는 영향 평가)

  • Aaqib, Muhammad;Park, Duhee;Kim, Hansup;Adeel, Muhammad Bilal;Nizamani, Zubair Ahmed
    • Journal of the Korean Geotechnical Society
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    • v.36 no.12
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    • pp.77-86
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    • 2020
  • In this study, the importance of implied strength correction for shallow depths at a region of moderate to low seismicity with primary focus on its effect upon site natural period and mean period of the ground motion is investigated. In addition to the most commonly used Modified Kondner-Zelasko (MKZ) model, this paper uses a quadratic/hyperbolic (GQ/H) model that can capture the stress - strain response at large strains as well as small strain stiffness dependence. A total of six site profiles by downhole tests are used and 1D site response analyses are performed using three input motions with contrasting mean periods. The difference between non-corrected and corrected analyses is conditional on the site period as well as mean ground motion period. The effect of periods is analyzed by correlating them with the effective peak ground acceleration, maximum shear strains and amplification factors. The comparative study reveals that the difference is more prominent in soft sites with long site periods. Insignificant differences are observed when soil profiles are subjected to ground motion with very short mean period.

Assessing Infinite Failure Software Reliability Model Using SPC (Statistical Process Control) (통계적 공정관리(SPC)를 이용한 무한고장 소프트웨어 신뢰성 모형에 대한 접근방법 연구)

  • Kim, Hee Cheul;Shin, Hyun Cheul
    • Convergence Security Journal
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    • v.12 no.6
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    • pp.85-92
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    • 2012
  • There are many software reliability models that are based on the times of occurrences of errors in the debugging of software. It is shown that it is possible to do asymptotic likelihood inference for software reliability models based on infinite failure model and non-homogeneous Poisson Processes (NHPP). For someone making a decision about when to market software, the conditional failure rate is an important variables. The finite failure model are used in a wide variety of practical situations. Their use in characterization problems, detection of outliers, linear estimation, study of system reliability, life-testing, survival analysis, data compression and many other fields can be seen from the many study. Statistical Process Control (SPC) can monitor the forecasting of software failure and there by contribute significantly to the improvement of software reliability. Control charts are widely used for software process control in the software industry. In this paper, we proposed a control mechanism based on NHPP using mean value function of log Poission, log-linear and Parto distribution.

Assessment of Turbulent Spectral Estimators in LDV (LDV의 난류 스펙트럼 추정치 평가)

  • 이도환;성형진
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.9
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    • pp.1788-1795
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    • 1992
  • Numerical simulations have been performed to investigate various spectral estimators used in LDV signal processing. In order to simulate a particle arrival time statistics known as the doubly stochastic poisson process, an autoregressive vector model was adopted to construct a primary velocity field. The conditional Poisson process with a random rate parameter was generated through the rescaling time process using the mean value function. The direct transform based on random sampling sequences and the standard periodogram using periodically resampled data by the sample and hold interpolation were applied to obtain power spectral density functions. For low turbulent intensity flows, the direct transform with a constant Poisson intensity is in good agreement with the theoretical spectrum. The periodogram using the sample and hold sequences is better than the direct transform in the view of the stability and the weighting of the velocity bias for high data density flows. The high Reynolds stress and high fluctuation of the transverse velocity component affects the velocity bias which increases the distortion of spectral components in the direct transform.

Voice Personality Transformation Using a Probabilistic Method (확률적 방법을 이용한 음성 개성 변환)

  • Lee Ki-Seung
    • The Journal of the Acoustical Society of Korea
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    • v.24 no.3
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    • pp.150-159
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    • 2005
  • This paper addresses a voice personality transformation algorithm which makes one person's voices sound as if another person's voices. In the proposed method, one person's voices are represented by LPC cepstrum, pitch period and speaking rate, the appropriate transformation rules for each Parameter are constructed. The Gaussian Mixture Model (GMM) is used to model one speaker's LPC cepstrums and conditional probability is used to model the relationship between two speaker's LPC cepstrums. To obtain the parameters representing each probabilistic model. a Maximum Likelihood (ML) estimation method is employed. The transformed LPC cepstrums are obtained by using a Minimum Mean Square Error (MMSE) criterion. Pitch period and speaking rate are used as the parameters for prosody transformation, which is implemented by using the ratio of the average values. The proposed method reveals the superior performance to the previous VQ-based method in subjective measures including average cepstrum distance reduction ratio and likelihood increasing ratio. In subjective test. we obtained almost the same correct identification ratio as the previous method and we also confirmed that high qualify transformed speech is obtained, which is due to the smoothly evolving spectral contours over time.