• Title/Summary/Keyword: Sample handling

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A response probability estimation for non-ignorable non-response

  • Chung, Hee Young;Shin, Key-Il
    • Communications for Statistical Applications and Methods
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    • v.29 no.2
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    • pp.263-275
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    • 2022
  • Use of appropriate technique for non-response occurring in sample survey improves the accuracy of the estimation. Many studies have been conducted for handling non-ignorable non-response and commonly the response probability is estimated using the propensity score method. Recently, post-stratification method to obtain the response probability proposed by Chung and Shin (2017) reduces the effect of bias and gives a good performance in terms of the MSE. In this study, we propose a new response probability estimation method by combining the propensity score adjustment method using the logistic regression model with post-stratification method used in Chung and Shin (2017). The superiority of the proposed method is confirmed through simulation.

An Instrument for Measuring Take-out Food Safety Perception (테이크아웃 음식의 안전에 대한 고객인식도 측정을 위한 척도에 관한 연구)

  • Kim, Hak-Seon
    • Culinary science and hospitality research
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    • v.18 no.2
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    • pp.82-90
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    • 2012
  • This study was conducted to evaluate a take-out food safety perception instrument that could be used by foodservice establishments. A total of 324 responses was collected via online survey, and 299 responses (92.3%) were used for the statistical analysis. Data was randomly split into two groups. Exploratory Factor Analysis (EFA) was performed on the first split-half sample (n=150) to identify a factor structure using standard principal component analysis. EFA revealed three dimensions, titled "Consumer food safety perception," "Take-out food handling," and "Elements impacting on purchase decisions." Confirmatory Factor Analysis (CFA) was performed on the remaining half sample (n=149) using Structural Equation Modeling (SEM). CFA revealed acceptable absolute model fits for three dimensions and excellent comparative model fits for the instrument. These findings propose standardized measures that can be useful in assessing the take-out food safety perception.

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A Study of Ultrastructure on attachment of Soft Contact Lens Surface of Incubated Pseudomonas aeruginosa (배양된 Pseudomonas aeruginosa의 소프트 콘택트 렌즈 표면부착에 대한 미세구조적 연구)

  • Kim, Douk Hoon;Park, Yong Tae;You, Hae Byung
    • Journal of Korean Ophthalmic Optics Society
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    • v.5 no.2
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    • pp.11-14
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    • 2000
  • The soft contact lens was very simple technique in handling, good sensation in fitting, good effect of a beauty, and good attachment state on the cornea in physical movement. So that, the subjects have used the correct of visual acuity. If the contact lens handling have not skill, they have acquired the side effect on eye. To analysis of a study of ultrastructure on soft contact lens surface of incubated P. aeruginosa. We have observed the soft contact lens surface by SEM. We have founded the good technical method. On the method of sample process of manufacture, the best observation of samlpe tissue was $OsO_4$ postfixation and tannic acid treatment. In this case, P. aeruginosa was a rod shape and one cilia in ultrastructure and the identification was very good. But, On the process of manufacture have not used the $OsO_4$ and tannic acid treatment, this tissue sample appeared the foreign body materials and artifacts, and the identification of the P. aeruginosa was very difficult.

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An Automated High Throughput Proteolysis and Desalting Platform for Quantitative Proteomic Analysis

  • Arul, Albert-Baskar;Han, Na-Young;Lee, Hookeun
    • Mass Spectrometry Letters
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    • v.4 no.2
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    • pp.25-29
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    • 2013
  • Proteomics for biomarker validation needs high throughput instrumentation to analyze huge set of clinical samples for quantitative and reproducible analysis at a minimum time without manual experimental errors. Sample preparation, a vital step in proteomics plays a major role in identification and quantification of proteins from biological samples. Tryptic digestion a major check point in sample preparation for mass spectrometry based proteomics needs to be more accurate with rapid processing time. The present study focuses on establishing a high throughput automated online system for proteolytic digestion and desalting of proteins from biological samples quantitatively and qualitatively in a reproducible manner. The present study compares online protein digestion and desalting of BSA with conventional off-line (in-solution) method and validated for real time sample for reproducibility. Proteins were identified using SEQUEST data base search engine and the data were quantified using IDEALQ software. The present study shows that the online system capable of handling high throughput samples in 96 well formats carries out protein digestion and peptide desalting efficiently in a reproducible and quantitative manner. Label free quantification showed clear increase of peptide quantities with increase in concentration with much linearity compared to off line method. Hence we would like to suggest that inclusion of this online system in proteomic pipeline will be effective in quantification of proteins in comparative proteomics were the quantification is really very crucial.

Identification of College Students' Food Safety Awareness and Perceived Barriers to Proper Food Handling Practices

  • Cha, Myeong-Hwa;Park, Jyung-Rewng
    • Preventive Nutrition and Food Science
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    • v.10 no.1
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    • pp.74-80
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    • 2005
  • The purpose of this study was to investigate culinary arts and hospitality students' food safety practice behaviors, intentions, attitudes, and barriers to food safety compliance. This descriptive study used the self-report questionnaire. The convenience sample was composed of 266 college students majoring in culinary arts and hospitality. The students indicated that they never or rarely use a thermometer to determine if meats have been adequately cooked. Examples of positive food handling behaviors were hand washing, sanitation of fruits and vegetables, discarding of food past its expiration date, counter top sanitation, and proper food storage. Students strongly agreed it is their responsibility to practice food safety and to educate their employees about food safety. The primary barrier to proper food safety as ranked by student respondents is the misunderstanding about food labeling. Previous food safety education and internship experience appeared to improve the student respondents' perceived attitudes toward following the principles of food safety practices (p < 0.05), although behaviors and intentions to use the correct food safety practices were not affected. The findings of this study suggest that programs should consider integrating information and experiential learning opportunities in their courses that would be enhance student understanding about food safety. The outcomes of this study can be applied to develop food safety education materials and programs for culinary arts and hospitality students.

A Comparison of Thermal Performance of Double Low-E Glazing Window according to Various Material (더블로이유리 적용 창호의 구성요소에 따른 단열성능 비교 실험)

  • Jang, Cheol-Yong;Ahn, Byung-Lip;Kim, Chi-Hoon;Kim, Jun-Sub;Lee, Sung-Jae
    • 한국태양에너지학회:학술대회논문집
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    • 2011.04a
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    • pp.133-137
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    • 2011
  • Low-e glazing is classified as soft low-e glazing and hard low-e glazing. Hard low-e glazing can be temperable and its handling is comfortable because its coating film is a oxide film generated at high temperatures. But there is a fatal weakness that its insulation performance and shielding performance are lower compared to soft low-e glazing by low electrical conductivity of coating film. Soft low-e glazing is excellent because its coating film consists of Ag that is excellent electrical conductivity and it has strength that can supply various product consumers want. But soft low-e glazing has weaknesses that temperable and handling are difficult because Ag is oxidized easily. Therefore this study analyzes thermal performance of glazing by changing filling gas according to applying low-e glazing through simulation to judge performance before making sample. After this process, a comparative experimental study was done through TVS by making temperable low-e glazing.

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The Effect of Relationship Marketing on Service Quality and Customer Loyalty: An Empirical Study in Indonesia

  • MAMUSUNG, Robby Tanod;NIMRAN, Umar;SUHARYONO, Suharyono;KUSUMAWATI, Andriani
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.7
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    • pp.533-543
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    • 2021
  • The purpose of this research is to examine and analyze the effect of Relationship Marketing on service quality and customer loyalty, especially in the context of the retail industry. In retail industry, Relationship Marketing is the key to increase and maintain a large pool of customers. This research was conducted in North Sulawesi Province with a sample size of 155 supermarket customers. The sampling technique used for the study is the purposive sampling. Data was analyzed using SEM based on GeSCA components. The results showed that Relationship Marketing had a significant positive effect both on service quality and customer loyalty. The commitment, communication, conflict handling, and competence play an important role in improving service quality which ultimately makes customers loyal. In addition, the relationship between service quality and customer loyalty, also has significant positive findings. These findings are in line with the concept of SERVQUAL and The Commitment-Trust Theory. The implication of the managerial research is that supermarket managers in North Sulawesi must focus and emphasize more on the Relationship Marketing dimension especially in terms of commitment, communication, conflict handling, and competence. Once these factors can be met, the quality of service will increase, and it causes an increase in customer loyalty to shop more at the supermarket.

Bacterial community comparison revealed by metagenomic analysis and physicochemical properties of eastern little tuna (Euthynnus affinis) with storage temperature differences

  • Asadatun Abdullah;Rahadian Pratama;Tati Nurhayati;Windy Sibuea;Sabila Diana Ahmad Sauqi
    • Fisheries and Aquatic Sciences
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    • v.26 no.10
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    • pp.593-604
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    • 2023
  • Post-harvest handling and hygienic level of aquatic products significantly affect the quality and level of safety. Cold chain control is one of the determining factors for the quality of fish and the bacterial community that grows on the fish. Identification of spoilage bacteria and pathogens in aquatic products must be made because it will determine the physical and chemical quality. A molecular identification method with high sensitivity is the solution. This study aims to identify the quality of fish and bacterial communities that grow. The research procedures included sample collection, pH measurement, drip loss measurement, transportation and cold storage treatment, DNA extraction, DNA sequencing, sequence analysis, and bioinformatics analysis. The conclusion obtained from this study is that the simulation of the cold chain system applied to eastern little tuna does not significantly affect changes in the water activity value, pH, and drip loss. The insignificant change indicates that the eastern little tuna samples are still in good quality. The bioinformatics analysis showed the highest diversity and abundance of the bacterial community came from the Gammaproteobacterial class.

Concordance Rate Between the Ratings of Clinician and Self Ratings of Worker on a Functional Capacity Evaluation

  • Choi, Bong-sam
    • Physical Therapy Korea
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    • v.23 no.4
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    • pp.71-80
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    • 2016
  • Background: Functional capacity evaluations (FCEs) are designed to systematically assess the capacity to perform work-related tasks and to determine worker's ability to return to the previous job following work-related injuries. These evaluations may be rated either by clinician or worker. There has been a lack of consensus between the two scoring methods. Objects: This study aimed: 1) to confirm if the data are fit to the Rasch rating scale model and 2) to investigate the item-level concordance rate between the ratings of clinician and injured worker of the FCE. Methods: A cross-sectional study was conducted with a sample (n=124) of a rehabilitation program with the Occupational Rehabilitation Data Base for workers with low back pain. The functional capacity evaluation at admission and discharge was administered to clinicians and workers. The data were analyzed using both classical test theory-based Pearson's r and intra-class coefficient followed by item-level analysis with Rasch rating scale model. Results: All items of the FCE, except sitting items rated by clinician at admission and handling items rated by both clinician and worker throughout admission and discharge, were acceptable fit statistics with minor out of ranges for a misfit criterion. This may indicate that the items of the FCE overall fit to the Rasch rating scale model. Few problematic items responding differently to clinician and worker both at admission and discharge were detected with the differential item functioning analysis despite the excellent concordance rate using the two conventional statistics-sitting and handling items at admission and handling item at discharge. Conclusion: The item-level speculations using Rasch analysis of the FCE demonstrate that the ratings of clinician and self ratings of worker were psychometrically acceptable though there was an apparent discrepancy between the raters both at admission and discharge.

A study to improve the accuracy of the naive propensity score adjusted estimator using double post-stratification method (나이브 성향점수보정 추정량의 정확성 향상을 위한 이중 사후층화 방법 연구)

  • Leesu Yeo;Key-Il Shin
    • The Korean Journal of Applied Statistics
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    • v.36 no.6
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    • pp.547-559
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    • 2023
  • Proper handling of nonresponse in sample survey improves the accuracy of the parameter estimation. Various studies have been conducted to properly handle MAR (missing at random) nonresponse or MCAR (missing completely at random) nonresponse. When nonresponse occurs, the PSA (propensity score adjusted) estimator is commonly used as a mean estimator. The PSA estimator is known to be unbiased when known sample weights and properly estimated response probabilities are used. However, for MNAR (missing not at random) nonresponse, which is affected by the value of the study variable, since it is very difficult to obtain accurate response probabilities, bias may occur in the PSA estimator. Chung and Shin (2017, 2022) proposed a post-stratification method to improve the accuracy of mean estimation when MNAR nonresponse occurs under a non-informative sample design. In this study, we propose a double post-stratification method to improve the accuracy of the naive PSA estimator for MNAR nonresponse under an informative sample design. In addition, we perform simulation studies to confirm the superiority of the proposed method.