134 research outputs found

    Appropriate use of parametric and nonparametric methods in estimating regression models with various shapes of errors

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    In this paper, a practical estimation method for a regression model is proposed using semiparametric efficient score functions applicable to data with various shapes of errors. First, I derive semiparametric efficient score vectors for a homoscedastic regression model without any assumptions of errors. Next, the semiparametric efficient score function can be modified assuming a certain parametric distribution of errors according to the shape of the error distribution or by estimating the error distribution non-parametrically. Nonparametric methods for errors can be used to estimate the parameters of interest or to find an appropriate parametric error distribution. In this regard, the proposed estimation methods utilize both parametric and nonparametric methods for errors appropriately. Through numerical studies, the performance of the proposed estimation methods is demonstrated.Comment: 2 figure

    Generative Neural Fields by Mixtures of Neural Implicit Functions

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    We propose a novel approach to learning the generative neural fields represented by linear combinations of implicit basis networks. Our algorithm learns basis networks in the form of implicit neural representations and their coefficients in a latent space by either conducting meta-learning or adopting auto-decoding paradigms. The proposed method easily enlarges the capacity of generative neural fields by increasing the number of basis networks while maintaining the size of a network for inference to be small through their weighted model averaging. Consequently, sampling instances using the model is efficient in terms of latency and memory footprint. Moreover, we customize denoising diffusion probabilistic model for a target task to sample latent mixture coefficients, which allows our final model to generate unseen data effectively. Experiments show that our approach achieves competitive generation performance on diverse benchmarks for images, voxel data, and NeRF scenes without sophisticated designs for specific modalities and domains

    Antecedents to Sales Associates Turnover in Apparel Retailing: Development of a Conceptual Model

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    Retail managers are concerned with turnover as the cost associated with replacing lost employees is high. To replace a lost employee, you must recruit applicants, conduct interviews that pull current employees out of their regular work, and once a person is hired, invest in training and orientation. There is also the cost of lowered productivity during the time period when the untrained individual is learning the new job. Estimates of the price to replace a worker vary but a common estimate is upwards of twice an employee’s salary (“How to reduce”, 2013). Turnover can also damage morale among remaining employees. Bottom line is a high turnover rate eats into company profits

    Factors Affecting the Perception of Importance and Practice of Patient Safety Management among Hospital Employees in Korea

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    SummaryPurposeThe study was undertaken to identify factors affecting perception of the importance and practice of patient safety management (PSM) among hospital employees in Korea.MethodsThis study was conducted using a descriptive design and a self-report questionnaire. Two hundred and eighty employees were recruited from three hospitals using a convenience sampling method. Measures were perception of the importance, practice, and characteristics of PSM. Data were analyzed using descriptive statistics including t test, one-way analysis of variance, Pearson's correlation analysis, and multiple regression.ResultsFactors affecting perception of the importance of PSM were whether hospital employees were in contact with patients while on duty, weekly working hours, education on PSM, and perceived adequacy of PSM system construction. Factors affecting the practice of PSM were perceived adequacy of work load, perceived adequacy of PSM system construction and perception of its importance.ConclusionThe findings of this study indicate a need for developing strategies to improve perception of the importance and practice of PSM among all hospital employees, and provide a reference for future experimental studies

    Luciferase-Rose Bengal Conjugates for Single Oxygen Generation by Bioluminescence Resonant Energy Transfer

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    Conjugates of Rose Bengal and Renilla luciferase generated singlet oxygen upon binding with coelenterazine via bioluminescence resonance energy transfer (BRET). Since the applications of conventional PDT have been limited to superficial lesions due to the limited light penetration in tissue, BRET activated PDT which does not require external light illumination may overcome the limitations of conventional PDT.115Ysciescopu

    Investigating the spatio-temporal variation of hepatitis A in Korea using a Bayesian model

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    Hepatitis A is a water-borne infectious disease that frequently occurs in unsanitary environments. However, paradoxically, those who have spent their infancy in a sanitary environment are more susceptible to hepatitis A because they do not have the opportunity to acquire natural immunity. In Korea, hepatitis A is prevalent because of the distribution of uncooked seafood, especially during hot and humid summers. In general, the transmission of hepatitis A is known to be dynamically affected by socioeconomic, environmental, and weather-related factors and is heterogeneous in time and space. In this study, we aimed to investigate the spatio-temporal variation of hepatitis A and the effects of socioeconomic and weather-related factors in Korea using a flexible spatio-temporal model. We propose a Bayesian Poisson regression model coupled with spatio-temporal variability to estimate the effects of risk factors. We used weekly hepatitis A incidence data across 250 districts in Korea from 2016 to 2019. We found spatial and temporal autocorrelations of hepatitis A indicating that the spatial distribution of hepatitis A varied dynamically over time. From the estimation results, we noticed that the districts with large proportions of males and foreigners correspond to higher incidences. The average temperature was positively correlated with the incidence, which is in agreement with other studies showing that the incidences in Korea are noticeable in spring and summer due to the increased outdoor activity and intake of stale seafood. To the best of our knowledge, this study is the first to suggest a spatio-temporal model for hepatitis A across the entirety of Korean. The proposed model could be useful for predicting, preventing, and controlling the spread of hepatitis A
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