• Safety and Health at Work
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• v.10 no.3
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• pp.370-376
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• 2019

Background: Respirator fit testing is a method to assess if the respirator provides an adequate face seal for the worker. Methods: Workers from four Norwegian smelters were invited to participate in the study, and 701 respirator fit tests were performed on 127 workers. Fourteen respirator models were included: one FFABE1P3 and 11 FFP3 respirator models produced in one size and two silicone half masks with P3 filters available in three sizes. The workers performed a quantitative fit test according to Health and Safety Executive 282/28 with 5-6 different respirator models, and they rated the respirators based on comfort. Predictors of overall fit factors were explored. Results: The pass rate for all fit tests was 62%, 56% for women, and 63% for men. The silicone respirators had the highest percentage of passed tests (92-100%). The pass rate for the FFP3 models varied from 19-89%, whereas the FFABE1P3 respirator had a pass rate of 36%. Five workers did not pass with any respirators, and 14 passed with all the respirators tested. Only 63% passed the test with the respirator they normally used. The mean comfort score on the scale from 1 to 5 was 3.2. The respirator model was the strongest predictor of the overall fit factor. The other predictors (age, sex, and comfort score) did not improve the fit of the model. Conclusion: There were large differences in how well the different respirator models fitted the Norwegian smelter workers. The results can be useful when choosing which respirators to include in respirator fit testing programs in similar populations.

• Tunnel and Underground Space
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• v.31 no.6
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• pp.460-468
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• 2021

A TBM is an equipment that excavates a tunnel with a full face by rotating a circular cutter head and its advantages are fast excavation rate and safe construction. A TBM, which is primarily used for tunnel excavation on civil construction sites, is easily adaptable to information and communication technology. Research related to unmanned and automated technology is being actively pursued. TBM applications for mining and energy resource development in other countries were investigated in this study. The difference of TBM applications between the mining and energy resource development and civil construction sites was examined. Technical factors such as geological conditions, depth, site access, TBM launching, alignment and inclination, TBM size, and others that should be considered when choosing a TBM were investigated. Finally, the advantages and disadvantages of TBM application in mines and the technical requirements for TBM for successful mine application are summarized.

• Korean Journal of Community Nutrition
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• v.27 no.5
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• pp.397-405
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• 2022

Objectives: This study examines the effect on the frequency of ramyeon consumption based on who checks nutrition labels and on the levels of sodium-related nutrition knowledge among middle school students in the Incheon area. Methods: Self-administered questionnaires were completed by 359 students (143 males and 216 females) from May to October 2021. General information as well as ramyeon-eating behaviors were surveyed. The frequency of ramyeon consumption was compared depending on who checks nutrition labels and on the amount of sodium-related nutrition knowledge students have. Both 𝛘² tests and t-tests were conducted for categorical and mean comparisons. Results: Regarding the consumption of ramyeon, 46% of the students replied that they eat it alone at home. The criteria for choosing the kind of ramyeon to eat were taste (79.4%), price (9.2%), brand and new products (4.5%), nutrition (2.2%), weight control (2.2%), and other factors (2.5%). When purchasing ramyeon, more students replied that they did not read nutrition labels (66.0%) compared to those who did read labels (34.0%). Answers to questions on sodium-related nutrition earned an average of 6.84 out of nine points (males, 6.72 points, females, 6.91 points, ns). The average frequency of ramyeon consumption was 1.67 times per week (males, 1.66, females, 1.68, ns). The frequency of ramyeon consumption by students who checked nutrition labels was lower than for students who did not check labels (1.44 times per week vs. 1.79 times per week, P < 0.05). Conclusions: Students who checked nutrition labels reported a lower frequency of ramyeon consumption than students who did not check them. Education on checking nutrition labels may reduce the consumption of processed foods such as ramyeon and may lead to making healthy choices when purchasing food.

• Journal of Korea Trade
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• v.24 no.8
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• pp.63-80
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• 2020

Purpose - Recent empirical studies have shown that FDI is expected to be strongly associated with democratic governance, political stability, and sound macroeconomic conditions of the host country. We attempt to take it a step further to see if governments implement a major change in institutional characteristics, will the institutional reform toward better governance have a substantive effect in enhancing FDI inflows. This paper thus aims to analyze the importance of good governance as an important factor in the attractiveness of FDI inflows in ASEAN+3 (Korea, China, Japan) countries. Design/methodology - To determine the effects of good governance on FDI inflows across ASEAN+3 countries recorded between 1996-2018, the Worldwide Governance Indicators (WGI) are used to investigate the impact of good governance on FDI inflows. The model has been estimated by using fixed effects to show the robustness of the results. Findings - Our main findings can be summarized as follows: Political Stability, Rule of Law, and Voice and Accountability have a statistically significant impact on the inflow of FDI in the ASEAN+3 Countries, especially for Korean economy. Moreover, GDP growth continue to exert their positive influence. However, Regulatory Quality, Government Effectiveness and Control of Corruption, though equally important, are insignificant to attract FDI inflows. The key finding is that good governance has a significant impact on inward FDI in the ASEAN+3 countries. Originality/value - Existing studies focus on the impact of political factors on FDI across countries. This paper instead attempts to investigate which type of good governance is the most important in promoting FDI inflows across ASEAN+3 countries, which is essential for multinationals to consider when choosing a foreign site as a possible FDI destination.

• The korean journal of orthodontics
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• v.52 no.6
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• pp.387-398
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• 2022

Objective: Controlling the incisal inclination is fundamental in orthodontics. However, the relationship between the inclination prescription and its clinical outcome is not obvious, and the incisal inclination changes generated by different bracket prescriptions were investigated. Methods: Twenty-eight non-extraction dental Class II patients (15 females, 13 males; mean age = 12.9) were retrospectively analyzed. Patients were treated using passive self-ligating fixed appliances with three inclination prescriptions for maxillary incisors (high, standard, low), and two for mandibular incisors (standard, low). Clinical outcomes were compared among different prescriptions, and regression analysis was used to explain the effects of bracket prescriptions and to understand the prescription selection criteria (α = 0.05). Results: For maxillary central incisors, low and high prescriptions were related to linguoversion (p = 0.046) and labioversion (p = 0.005), respectively, while standard prescription maintained the initial dental inclination. Maxillary lateral incisors did not show significant changes. For mandibular incisors, low prescription led to linguoversion (p = 0.005 for central incisors, p = 0.010 for lateral incisors), while standard prescription led to labioversion (p = 0.045 for central incisors, p = 0.005 for lateral incisors). The factors affecting inclination changes were the imposed change and selected prescription, while prescription selection was influenced by the initial dental inclination and initial intercanine distance. Conclusions: The direction of correction of incisal inclination can be controlled by choosing a certain prescription, but the final inclination may show limited consistency with it. The amount of imposed inclination change was the most relevant predictor of the clinical outcome.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1041-1041
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• 2001

Removal of variability in spectra data before the application of chemometric modeling will generally result in simpler (and presumably more robust) models. Particularly for sparsely sampled data, such as typically encountered in diode array instruments, the use of Savitzky-Golay (S-G) derivatives offers an effective method to remove effects of shifting baselines and sloping or curving apparent baselines often observed with scattering samples. The application of these convolution functions is equivalent to fitting a selected polynomial to a number of points in the spectrum, usually 5 to 25 points. The value of the polynomial evaluated at its mid-point, or its derivative, is taken as the (smoothed) spectrum or its derivative at the mid-point of the wavelength window. The process is continued for successive windows along the spectrum. The original paper, published in 1964 [1] presented these convolution functions as integers to be used as multipliers for the spectral values at equal intervals in the window, with a normalization integer to divide the sum of the products, to determine the result for each point. Steinier et al. [2] published corrections to errors in the original presentation [1], and a vector formulation for obtaining the coefficients. The actual selection of the degree of polynomial and number of points in the window determines whether closely situated bands and shoulders are resolved in the derivatives. Furthermore, the actual noise reduction in the derivatives may be estimated from the square root of the sums of the coefficients, divided by the NORM value. A simple technique to evaluate the actual convolution factors employed in the calculation by the software will be presented. It has been found that some software packages do not properly account for the sampling interval of the spectral data (Equation Ⅶ in [1]). While this is not a problem in the construction and implementation of chemometric models, it may be noticed in comparing models at differing spectral resolutions. Also, the effects on parameters of PLS models of choosing various polynomials and numbers of points in the window will be presented.

• Advances in concrete construction
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• v.15 no.3
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• pp.203-213
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• 2023

New techniques, technologies, and materials should be used to design and build sports stadiums. Since this century, much progress has been made in covering the roofs of sports stadiums, and the possibility of accurate computer calculation has been provided for stadiums, so by choosing a new structure, we can double the beauty and resistance of these stadiums. A stadium has an excellent and valuable design when its structure, shell, building, materials, and joinery follow a high architectural idea at all levels and scales. This article examines the mechanical performance of polymer cement strength in the construction of football stadiums, along with their structural knowledge in the form of the best examples in the world. Portland cement is one of the most used materials for constructing football stadiums. However, its production requires spending a lot of money, wasting energy, and damaging the environment. Considering the disadvantages in the production and consumption of concrete in different environments, it is necessary to find alternative materials. It should be used with cheaper, simpler technology, abundant primary resources, energy saving, less environmental damage, and better chemical and physical properties in concrete. High-strength concrete technology is considered a new development in the construction industry of concrete structures. In hardened concrete, strength and durability are two main factors, and as the compressive strength of concrete increases, concrete becomes more brittle. As a result, its tensile strength does not increase in proportion to the increase in compressive strength and has less strain tolerance. For this reason, the need to use is evident from the fibers in high-strength concrete. Fibers are used in concrete to increase tensile strength, prevent crack propagation, and significantly increase softness. The increase with the change of these resistances depends on the strength of concrete without fibers, the shape of fibers, and the percentage of fibers. This cement is obtained from the wastes of chemical and petrochemical industries and the wastes from coal combustion, which have the properties mentioned as substitutes for Portland cement.

• Journal of the Korean Society of Food Culture
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• v.22 no.1
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• pp.43-57
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• 2007

This study was designed to identify the actual state of ready-to-eat street-foods usage in a college-town in northern part of seoul. For the empirical study, data was collected from customers who had eaten street-foods and a survey was conducted from 16 to 30, May 2006. The results showed that many respondents had irregular eating habits. More than 60% of them responded they usually skipped breakfast and the reason was no time. It was shown that they have had Frequent snacks and unbalanced diet. The results of survey are as follows ; 1. The major time for street-foods usage: p.m 3-5 (28.77%). 2. The frequency of street-foods usage: 1-2 times/week (43.85%). 3. The street-foods usage days of the week: weekday (52.79%). 4. The mean cost for the onetime purchase of street-foods usage: 1000-3000won (71.79%). 5. The monthly cost for the purchase of street-foods usage: below 50000won (81.84%). 6. The reason for street-foods usage: mainly convenience (60.61%). 7. The reason for minding street-foods : mainly insanitary (40.50)%. 8. Factors considered when choosing street-foods: tastes of the foods (65.08%). Also, it was shown that over 50% of respondents have considered the street-foods as the worth of meal replacement, and taken effective factor on eating habits for influx of new culture. It was indicated that problems of street-foods usage was the unbalanced nutrition for 81.8% of respondents and suggestions for improving the street-foods were sanitary controls for products for 63.4% of respondents.

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

• Korean Journal of Social Welfare Studies
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• v.40 no.1
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• pp.63-86
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• 2009

This research aims to focus on how the perception of discrimination changes through the mediation effect of various leisure activities between the characteristic of disability and perception of discrimination. This research is based on the 2005 survey of the disabled conducted by the Korea Institute for Health and Social Affairs, which studied 1,241 seniors over 65 with physical disabilities. The results of the study are as follows. First, the type of disability, duration of disability, and IADL are the influencing factors to the relation between the characteristic of disability and individual perception of discrimination. Second, the type of leisure activities was influenced by the characteristics of their disability. Especially, the degree of IADL was statistically significant in choosing the type of leisure. Third, leisure activities with specific purposes, such as amusement and self-development, have only partial mediation effect on the relation between the characteristic of disability and individual perception of discrimination.