• Smart Structures and Systems
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• v.16 no.3
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• pp.383-399
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• 2015

Today, as railways increase their capacity and speeds, it is more important than ever to be completely aware of the state of vehicles fleet's condition to ensure the highest quality and safety standards, as well as being able to maintain the costs as low as possible. Operation of a modern, dynamic and efficient railway demands a real time, accurate and reliable evaluation of the infrastructure assets, including signal networks and diagnostic systems able to acquire functional parameters. In the conventional system, measurement data are reliably collected using coaxial wires for communication between sensors and the repository. As sensors grow in size, the cost of the monitoring system can grow. Recently, auto-powered wireless sensor has been considered as an alternative tool for economical and accurate realization of structural health monitoring system, being provided by the following essential features: on-board micro-processor, sensing capability, wireless communication, auto-powered battery, and low cost. In this work, an original harvester device is designed to supply wireless sensor system battery using train bogie energy. Piezoelectric materials have in here considered due to their established ability to directly convert applied strain energy into usable electric energy and their relatively simple modelling into an integrated system. The mechanical and electrical properties of the system are studied according to the project specifications. The numerical formulation is implemented with in-house code using commercial software tool and then experimentally validated through a proof of concept setup using an excitation signal by a real application scenario.

• Atmosphere
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• v.27 no.2
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• pp.235-249
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• 2017

This paper describes methodology verifying near-surface predictability of numerical weather prediction models against the surface synoptic weather station network (SYNOP) observation. As verification variables, temperature, wind, humidity-related variables, total cloud cover, and surface pressure are included in this tool. Quality controlled SYNOP observation through the pre-processing for data assimilation is used. To consider the difference of topographic height between observation and model grid points, vertical inter/extrapolation is applied for temperature, humidity, and surface pressure verification. This verification algorithm is applied for verifying medium-range forecasts by a global forecasting model developed by Korea Institute of Atmospheric Prediction Systems to measure the near-surface predictability of the model and to evaluate the capability of the developed verification tool. It is found that the verification of near-surface prediction against SYNOP observation shows consistency with verification of upper atmosphere against global radiosonde observation, suggesting reliability of those data and demonstrating importance of verification against in-situ measurement as well. Although verifying modeled total cloud cover with observation might have limitation due to the different definition between the model and observation, it is also capable to diagnose the relative bias of model predictability such as a regional reliability and diurnal evolution of the bias.

• Korean Medical Education Review
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• v.23 no.1
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• pp.37-45
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• 2021

In light of the need for a tool to evaluate the clinical practice education environment as perceived by medical and nursing students, this study is was conducted to develop and validate the Korean version of the Undergraduate Clinical Education Environment Measure (K-UCEEM) as a measurement tool for managing the clinical practice education climate and quality of education. For validation, the UCEEM consisting of 25 items developed by Pia Strand in 2013 was adapted according to standard translation procedures. The K-UCEEM questionnaire was administered to 73 medical students and 135 nursing students who participated in clinical practice at one medical institution. Exploratory factor analysis and confirmatory factor analysis were conducted to confirm the validity of the instrument's structure. In order to determine referential validity, the relationships among stresses in clinical practice were examined, and differences in factor scores were compared by gender and college. It was confirmed that the scale of 24 items and five factors showed a moderate model fitness index. The reliability of the factors ranged from 0.786 to 0.867. In addition, all five factors were found to have negative correlations with the clinical practice stress sub-factor, and there were statistically significant differences by gender and college. Through this study, the validity and reliability of the K-UCEEM were verified. In the future, it is expected that further verification of the scale, as well as evaluation and improvement of the clinical practice education environment based on this scale, will occur.

• Journal of the Korea Convergence Society
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• v.13 no.4
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• pp.89-101
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• 2022

This study attempted to develop a scale that Interpersonal Caring Behavior Measurement Tool, based on Kim's Interpersonal caring theory, and confirmed its reliability and validity. The items were used as 50 items of 10 concepts based on the Su-ji Kim's interpersonal care theory in Korea developed by Seon-hee Yun. Subjects were nurses working at a general hospital or higher, who agreed to participate in this study. As a result of the study, 50 questions in 10 concepts of the first were derived from active listening, accepting, complimenting, noticing, and companioning through exploratory and confirmatory factor analysis, and criterion validity and reliability were verified. This tool is meaningful in that it can measure Caring Behavior from the perspective of the subject and family, and can be used as an index to visualize the quality improvement of nursing care by quantifying it.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.3
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• pp.104-114
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• 2022

The purpose of using coolant in machining is both to increase a tool life and also to prevent product deformation and thus, stabilize the surface quality by lubricating and cooling the tool and the machining surface. However, a very small amount of cutting mist should be used because chlorine-based extreme pressure additives are used to generate environmental pollutants in the production process and cause occupational diseases of workers. In this study, medical titanium alloy (Ti-6Al-7Nb) was subjected to a processing experiment by selecting factors and levels affecting cutting power in the processing of the Aerosol Dry Lubrication (ADL) method using vegetable oil. The machining shape was a slot to sufficiently reflect the effect of the cutting depth. As for the measurement of cutting force, the trend of cutting characteristics was identified through complete factor analysis. The factors affecting the cutting force of ADL slot processing were identified using the reaction surface analysis method, and the characteristics of the cutting force according to the change in factor level were analyzed. As the cutting speed increased, the cutting force decreased and then increased again. The cutting force continued to increase as the feed speed increased. The increase in the cutting depth increased the cutting force more significantly than the increase in the cutting speed and the feed speed. Through the reaction surface analysis method, the regression equation for predicting cutting force was identified, and the optimal processing conditions were proposed. The cutting force was predicted from the secondary regression equation and compared with the experimental value.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.164-173
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• 2019

The purpose of this research was to introduce a network analysis method for analyzing technology trends in the aerospace industry at the Farnborough International Airshow (FIA), one of the world's three major airshows. Civil and defense companies and government and military officials from 112 countries and 1,500 agencies convened at FIA 2018 to share and explore recent trends in the aerospace industry. We studied aerospace technologies from 45 countries, 1,108 exhibiters, and 223 technology categories via centrality analysis. The results from the network analysis showed that machining is the center of aerospace technology. However, there were quite different tendencies, depending on the region and country. The centers of aerospace technology are machining in Europe and the United Kingdom, aircraft components in Asia, and engine components/controls in the United States. In Korea, no one key technology was recognized, due to the country's small attendance. We hope this research will be conducive to aerospace technology-and-research planning, and that it will be an appropriate tool to help domestic manufacturers boost their exports.

• Journal of the Korean Applied Science and Technology
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• v.36 no.1
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• pp.90-101
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• 2019

The study wanted to compare the use status of general beauty salons and men's hair salons for male customers managed by male practitioners and to check the impact of service quality awareness on satisfaction and loyalty. A total of 405 people were used as analysis materials. Principle Component Analysis was used to verify the reliability and validity of the measurement tool. Sub-factors of service quality recognition have derived expertise, affinity, reliability and persistence. The validity and reliability of satisfaction and loyalty were verified. Based on the results of this study, the differences in hair involvement in general beauty salons and men's specialty salons, service quality awareness, satisfaction and loyalty were identified. The relationship between professionalism, affinity, reliability, persistence by sub-factor of service quality awareness has been identified with satisfaction, loyalty and statistically significant positive (+). In addition, male professional beauty salons had positive effects on service quality awareness of satisfaction and loyalty. Service quality satisfaction has been confirmed to have a positive impact on loyalty. In this study, the beauty of the men through the significant marketing potential use as basic data on the market feed that the portraits.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.3104-3104
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• 2001

The research described here was undertaken with the aim of monitoring, optimizing and ultimately controlling the production of heterofermentative microbes used as starters in the salami industry. The use of starter cultures in the fermented meats industry is a well-established technique used to shorten and standardize the ripening process, and to improve and control the organoleptic quality of the final product. Starter cultures are obtained by the submerged cultivation of suitable microorganisms in stirred, and sometimes aerated, fermenters where monitoring of key physiological parameters such as the concentration of biomass, substrates and metabolites suffers from the general lack of real-time measurement techniques applicable to aseptic processes. In this respect, the results of the present work are relevant to all submerged fermentation processes. Previous work on the application of on-line NIR spectroscopy to the lactic acid fermentation (Dosi et al. - Monreal NIR1995) had successfully used a system based on a measuring cell included in a circulation loop external to the fermenter. The fluid handling and sterility problems inherent in an external circulation system prompted us to explore the use of an in-line system where the NIR probe is immersed in the culture and is thus exposed to the hydrodynamic conditions of the stirred and aerated fluid. Aeration was expected to be a potential source of problems in view of the possible interference of air bubbles with the measurement device. The experimental set-up was based on an in-situ sterilizable NIR probe connected to the instrument by means of an optical fiber bundle. Preliminary work was carried out to identify and control potential interferences with the measurement, in particular the varying hydrodynamic conditions prevailing at the probe tip. We were successful in defining the operating conditions of the fermenter and the geometrical parameters of the probe (flow path, positioning, etc.) were the NIR readings were reliable and reproducible. The system thus defined was then used to construct and validate calibration curves for tile concentration of biomass, carbon source and major metabolites of two different microorganisms used as salami starters. Real-time measurement of such parameters coupled with the direct interfacing of the NIR instrument with the PC-based measurement and control system of the fermenter enabled the development of automated strategies for the interactive optimization of the starter production process.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.457-460
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• 2002

The image quality of three-dimensional (3D) images has been widely investigated by the qualitative analysis method. A need remains for an objective and quantitative method to assess the image quality of 3D volume-rendered images. The purpose of this study was to evaluate the quantitative accuracy of distance measurements on 3D volume-rendered images of a dry human skull by using multi-detector computed tomography (MDCT). A radiologist measured five times the twenty-one direct measurement line items composed among twelve reference points on the skull surface with a digital vernier caliper. The water filled skull specimen was scanned with a MDCT according to the section thicknesses of 1.25, 2.50, 3.75, and 5.00 mm for helical (high quality; pitch 3:1) scan mode. MDCT data were reconstructed with its acquisition section thickness and with 1.25 mm section thickness for all scans. An observer also measured seven times the corresponding items on 3D volume-rendered images with measuring tools provided by volumetric analysis software. The quantitative accuracy of distance measurements on the 3D volume-rendered images was statistically evaluated (p-value < 0.05) by comparatively analyzing these measurements with the direct distance measurements. The accuracy of distance measurements on the 3D volume-rendered MDCT images acquired with 1.25, 2.50, 3,75 and 5.00 mm section thickness and reconstructed with its section thickness were 48%, 33%, 23%, and 14%, respectively. Meanwhile, there were insignificant statistical differences in accuracy of distance measurements among 3D volume-rendered images reconstructed with 1.25 mm section thickness for the each acquisition section thickness. MDCT images acquired with thick section thickness and reconstructed with thin section thickness in helical scan mode should be effectively used in medical planning of 3D volume-rendered images. The quantitative analysis of distance measurement may be a useful tool for evaluating the quantitative accuracy and the defining optimal parameters of 3D volume-rendered CT images.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.266-274
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• 2021

Ship officers are subject to excessive job stress, which has negative physical and psychological impacts and may adversely affect the smooth supply and demand of human resources. In this study, a mobile web application was developed as a tool for systematic job stress measurement and management of officers and verified through quality evaluation. Requirement analysis was performed by ship officers and staff in charge of human resources of shipping companies, and the results were reflected in the application configuration step. The application was designed according to the waterfall model, which is a traditional software development method, and functions were implemented using JSP and Spring Framework. Performance evaluation on the user interface, confirmed that proper input and output results were implemented, and the respondent results and the database were configured in the administrator interface. The results of evaluation questionnaires for quality evaluation of the interface based on ISO/IEC 9126-2 metric were significant 4.60 for the user interface and 4.65 for the administrator interface in a 5-point scale. In the future, it is necessary to conduct follow-up research on the development of data analysis system through utilization of the collected big-data sets.