• Economic and Environmental Geology
• /
• v.37 no.1
• /
• pp.49-59
• /
• 2004

The concectration and distribution of contaminants obtained from a contaminated land investigation or an environmental geochemistry survey constitutes the basis of a decision-making process on environmental policies or of scientific researches. As the quality of data determines the reliability of the result, the investigation plan should be adjusted according to the purpose of the investigation. In general, the effort to improve the data quality had been focused mainly on the QA/QC procedures in laboratories. The rapid progress of analytical instrument has also contributed toward improving the analytical precision to a sacrificable degree. Nevertheless, in many cases, it is not the analytical precision that needs improvement for the better precision of overall measurement process: it is rather during the sampling process in the field that is responsible for the poor precision. To assess the data quality on a measured value, ISO recommends to provide information on "measurement uncertainty" along with the measured value. The measurement uncertainty in an environmental measurement context can be explained as the statistical number that expresses the degree of the uncertainty stemming from the sampling and analytical procedures. There is a cost involved in order to improve the precision of sampling and analytical methods so as to decrease the degree of measurement uncertainty. The economical point of compromise in an investigation planning can be achieved when the allowable degree of uncertainty has been set before-hand. The investigation can then be planned accordingly not to exceed the uncertainty limit. Furthermore, if the measurement uncertainty estimated from the preliminary investigation can be separated into sampling and analytical uncertainties, it can be used as a criterion where the resources for the investigation should be allotted cost-effectively to reinforce the weakest link of the whole investigation process. This paper aims to present a method of estimating the level of measurement uncertainty of a measured contamination concentration at a site used as an example and to show how the estimated uncertainty can be applied to serve the particular purpose of an investigation.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.12 no.1
• /
• pp.15-29
• /
• 2010

Spalling is a kind of instability phenomenon of surrounding rock around underground openings subjected to high in-situ stress according to the development of extension fractures. Three kinds of spalling criteria have been presented so far; however, all spalling criteria have the range of values so that the fuzziness and vagueness of spalling criterion cannot be avoided. In this study, a new fuzzy probability model is proposed to predict the probability of spalling in a systematic way by using fuzzy probability theory. Many of the underground opening projects worldwide are evaluated with the proposed method. Prediction results expressed as the spalling probability agree well with the in-situ observations. In particular, a new fuzzy probability model considering all three evaluation indices of spalling by adopting weighting factors based on relative reliability among three evaluation indices is able to resolve erroneous prediction of spalling by choosing only one prediction method. Moreover, the more reasonable value of spalling probability could have been obtained by adopting the modified damage index to the newly proposed fuzzy probability model.

• Journal of Preventive Medicine and Public Health
• /
• v.35 no.4
• /
• pp.359-374
• /
• 2002

Objectives : To develop a physical functioning instrument for older adults living in the community. Methods : A representative sample of 979 people aged 65 years or over were interviewed in-person. Of these, 199 people also completed a detailed in-hospital examination. The scale items were selected based on the frequency of endorsement, along with the item-total and inter-item correlations. The associations of the scale with their physical performance and clinical examination were analyzed to evaluate the criterion-related validity. Construct validity was assessed using factor analysis, and internal consistency through Cronbach's alpha and item-total correlations. Test-retest reliability was measured by agreement between the household survey and the repeat survey at the in-hospital examination. Results : Initially, 23 items on the level of difficulty, ranging from no difficulty to an inability to complete a task, with the specific mobility and self-care tasks were included. Those with a high frequency of endorsement and a low inter-item or item-total correlations were excluded, resulting in a 10-item Physical Functioning (PT) scale. Equal weights were given to each item and a summated score was calculated. Significant associations were found between the PF scores and the physical performance, surrey and clinical data. The scale revealed a 2-factor (mobility and self-care) structure. Cronbach's alpha was 0.92 and the item-total correlations were in the 0.63 to 0.78 range. Pearson's correlations for the test-retest ranged between 0.56 and 0.61. Conclusions : The newly developed Physical Functioning (PF) scale showed good psychometric properties in older people. Further work, however, is needed to improve its sensitivity to discriminate higher levels of functioning, in addition to assessing its predictive value in detecting changes in health.

• Journal of Hospice and Palliative Care
• /
• v.9 no.2
• /
• pp.86-92
• /
• 2006

Purpose: This study was conducted to develop a measuring tool for spiritual care performance of hospice team members. The tool may be utilized for providing hospice patients with more systematic and standardized spiritual tares. Methods: The concept and questions of the tool were developed, and then its validity and reliability were tested. For the validity and reliability tests, a self-reported questionnaire comprising 33 questions with 4 point scale ($1{\sim}4$), was developed, and the data were collected from 192 hospice team members from December 2005 to February 2006. Results: Thirty three questions, drafted through literature review and professional consultation, were reviewed by 20 professionals for their validity, were revised and supplemented resulted in the final 33 questions. The questions with a correlation coefficient grater than .30 were selected: all the 33 questions were selected based on this criterion. The reliability coefficient, Cronbarh's ${\alpha}$, was 0.95. The 33 questions were analyzed for factors, and six factors were extracted: relationship formation and communication, encouragement and promotion of spiritual growth, linking with spiritual resources, preparation of death, evaluation and quality control for spiritual intervention, Intervention, and spiritual assessment for intervention. Conclusion: The tool developed in this study includes six factors and has high level of reliability. This tool Will greatly contribute to assess and improve hospice care services, providing systematic and standardized spiritual cares for terminally ill patients and their families.

• Journal of Korean Academy of Nursing
• /
• v.27 no.4
• /
• pp.831-842
• /
• 1997

The purpose of the study was to test the reliability and validity of the Korean version of Task Self-Efficacy Scale for activities of dally living (ADL). The Task Self-Efficacy Scale was developed by Roberts(1996) for low-intensity exercise study with older people to predict their performance of ADL. The scale was translated and back translated by bilingual persons, and then was modified to resolve variations in the translations. The Korean version of Self-Efficacy Scale for ADL was then administered to 193 elderly people including 95 hospitalized patients and 98 outpatients or healthy people. Face to face interview was used to fill out the structured questionnaire, and each interview took approximately 30 minutes. The subjects for the study were 80 women and 112 men with an age range of 65 to 95 years(M=71 years) of whom 82.6% classified themselves as moderate or quite active Most subjects(80.2%) had an education level of elementary school or less. The Self-Efficacy Scale for ADL is measured on a 0 to 10 VAS, assessing three areas of ADL : self care activities, household tasks, and motor tasks. The higher the score is, the higher person's confidence in performing ADL. Psychometric testing revealed that the scale was found to be internally consistent, showing a Cronbach's alpha of .97 The scale was significantly correlated with subjects' level of activity and subjective assessment of their health status. Moderate correlation with health-related hardiness scale also supported the validity. Factor analysis was performed to confirm whether the scale represents the three sub-areas as suggested in the literature. The results of the factor analysis led to a three factor solution according to Kaiser's criterion, but the items were not strongly and cleanly loaded for the third factor. This can be explained in that, among the three sub-ADL areas of the self-efficacy scale, the areas of self care activities and household tasks seem to have similar levels of difficulty in performance with not enough differences for the self-efficacy scale to distinguish between the two areas. Therefore, one factor solution was suggested since ADL can be seen as a unit of activities at similar level of difficulty in performance. One factor solution explained 68.1% of variance of the 19-item scale and all items were correlated over .6 with the factor, showing that the selected factor solution fits the model. The results indicated that the Korean version of Task Self-Efficacy Scale for ADL was reliable and valid in producing useful information to evaluate the effects of various interventions toward promoting health and quality of life for elderly people.

• Fire Science and Engineering
• /
• v.31 no.2
• /
• pp.52-60
• /
• 2017

Numerical simulations were performed to evaluate the habitability of an operator for a cabinet fire in the main control room of a nuclear power plant presented in NUREG-1934. To this end, a Fire Dynamics Simulator (FDS), as a representative fire model, was used. As the criteria for determining the habitability of operator, toxic products, such as CO, were also considered, as well as radiative heat flux, upper layer temperature, smoke layer height, and optical density of smoke. As a result, the probabilities of exceeding the criteria for habitability were evaluated through the sensitivity analysis of the major input parameters and the uncertainty analysis of fire model for various fire scenarios, based on V&V (Verification and Validation). Sensitivity analyses of the maximum heat release rate, CO and soot yields, showed that the habitable time and the limit criterion, which determined the habitability, could be changed. The present methodology will be a realistic alternative to enhancing the reliability for a habitability evaluation in the main control room using uncertain information of cabinet fires.

• Journal of Family Resource Management and Policy Review
• /
• v.25 no.1
• /
• pp.35-45
• /
• 2021

Focusing on increasing of single-person households this study aims to develop a scale to measure the healthiness of lifestyle among single-person households. The concept of healthiness of lifestyle is based on the theories of family strength and family ecology. We draw 50 items that encompass basic needs, individual, familial, and social aspects of single-person life. Using a sample of 317 persons who live alone, this study examined a factor structure of the items and selected 44 items based on the results of factor analysis. Reliability and criterion- and construct validity were also examined. The final scale consists of four domains; basic needs (finance, housing, consumption, and future plan), work·life balance (time management, health, and stress), family relations, and social participation (social network, social interests, and community participation). This scale can be used as an assessment measure of the healthiness of lifestyle of single persons who participate in programs in Healthy and Multicultural Families Support Centers.

• Journal of the Korean Society of Safety
• /
• v.36 no.2
• /
• pp.49-57
• /
• 2021

In the case of military supplies, any potential failure and causes of failures must be considered. This study is aimed at examining the failure modes of a rotorcraft landing system to identify the priority items. Failure mode and effects analysis (FMEA) is applied to the rotorcraft landing system. In general, the FMEA is used to evaluate the reliability in engineering fields. Three elements, specifically, the severity, occurrence, and detectability are used to evaluate the failure modes. The risk priority number (RPN) can be obtained by multiplying the scores or the risk levels pertaining to severity, occurrence, and detectability. In this study, different weights of the three elements are considered for the RPN assessment to implement the FMEA. Furthermore, the FMEA is implemented using a fuzzy rule base, similarity aggregation model (SAM), and grey theory model (GTM) to perform a comparative analysis. The same input data are used for all models to enable a fair comparison. The FMEA is applied to military supplies by considering methodological issues. In general, the fuzzy theory is based on a hypothesis regarding the likelihood of the conversion of the crisp value to the fuzzy input. Fuzzy FMEA is the basic method to obtain the fuzzy RPN. The three elements of the FMEA are used as five linguistic terms. The membership functions as triangular fuzzy sets are the simplest models defined by the three elements. In addition, a fuzzy set is described using a membership function mapping the elements to the intervals 0 and 1. The fuzzy rule base is designed to identify the failure modes according to the expert knowledge. The IF-THEN criterion of the fuzzy rule base is formulated to convert a fuzzy input into a fuzzy output. The total number of rules is 125 in the fuzzy rule base. The SAM expresses the judgment corresponding to the individual experiences of the experts performing FMEA as weights. Implementing the SAM is of significance when operating fuzzy sets regarding the expert opinion and can confirm the concurrence of expert opinion. The GTM can perform defuzzification to obtain a crisp value from a fuzzy membership function and determine the priorities by considering the degree of relation and the form of a matrix and weights for the severity, occurrence, and detectability. The proposed models prioritize the failure modes of the rotorcraft landing system. The conventional FMEA and fuzzy rule base can set the same priorities. SAM and GTM can set different priorities with objectivity through weight setting.

• Journal of Family Resource Management and Policy Review
• /
• v.26 no.2
• /
• pp.53-70
• /
• 2022

This study aimed to develop a scale to measure the family strength of single-parent families. We analyzed the everyday life and demands of single-parent families using the theory of family strength to draw 78 items that encompass family basis, relationships, roles, social networks and family culture. Using a sample of 286 single-parent families through an online survey platform, we examined the factor structure of the items and selected 48 items based on the results of the factor analysis. Reliability, criterion and construct validity were also examined. The final scale comprised of five domains ; basis, parents' role, work-life balance, social network, lifestyle and household management. This scale can be used as an assessment measure of the family strength of single-parent families for consulting, case management and suggesting various programs in the field. This merit will help enhance the quality of programing for single-parent families at the Healthy Family Support Center and the development of family strength scales for various types of families.

• The Korean Journal of Franchise Management
• /
• v.13 no.1
• /
• pp.47-57
• /
• 2022

Purpose: Recently, it is common to see cases where an amount similar to the cost of a meal is spent on dessert, or an amount greater than the cost of a meal is spent on dessert. The generation MZ is showing a tendency of 'value consumption' by consuming values and beliefs in consideration of the recent impact on society and the environment. Therefore, this study aims to analyze the effect of dessert cafe quality and eco-friendly behavior on customer trust and loyalty targeting the generation MZ who have visited desert cafés. This study examined the mediating role of customer trust in the relationships between desert café quality, eco-friendly behavior and customer loyalty, and also the moderating effect of and eco-friendly behavior on customer trust and customer loyalty. Research design, data, and methodology: To achieve purposes of this study, 229 data were collected from respondents who visited desert café and analyzed using measurement model (reliability test and correlation analysis), Fornell-Larcker Criterion and Heterotrait-Monotrait Ratio (HTMT) assessment, and structural equation model (PLS-SEM) with SPSS 22.0 and SmartPLS 3.3.7. Results: The research results are as follows. First, desert cafes' quality positively influenced customer trust but did not customer loyalty. Second, desert cafes' eco-friendly behavior positively influenced customer trust and customer loyalty. Fourth, the interaction term of dessert cafe quality and eco-friendly behavior did not influence customer trust and customer loyalty. Conclusions: This study emphasized the necessity of service quality and eco-friendly behavior of dessert cafes by examining the relationship between the quality of dessert cafes and eco-friendly behaviors, customer trust and loyalty. It also found the importance of the role of trust in securing loyal customers. In order to secure and retain loyal customers, the owners of dessert cafes should make effortsto improve the quality of the cafes' products and services so that customers can feel a sense of trust, and actively publicize that they are practicing eco-friendly management. As a result of this study, it is intended to provide practical implications for the management of dessert cafes by understand ing the effects of product and service quality and eco-friendly behaviors of companies to bakery industry workers and start-ups.