• Nuclear Engineering and Technology
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• v.49 no.7
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• pp.1483-1488
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• 2017

In order to predict and control the environmental and health impacts of ionizing radiation in environmental sources such as groundwater, it is necessary to identify the radionuclides present. Beta-emitting radionuclides are frequently identified by measuring their characteristic energy spectra. The present work shows that self-attenuation effects from volume sources result in a geometry-dependent shift in the characteristic spectra, which needs to be taken into account in order to correctly identify the radionuclides present. These effects are shown to be compounded due to the subsequent shift in the photon spectra produced by the detector, in this case an inorganic solid scintillator ($CaF_2:Eu$) monitored using a silicon photomultiplier. Using tritiated water as an environmentally relevant, and notoriously difficult to monitor case study, analytical predictions for the shift in the energy spectra as a function of depth of source have been derived. These predictions have been validated using Geant4 simulations and experimental results measured using bespoke instrumentation.

• Journal of applied mathematics & informatics
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• v.33 no.5_6
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• pp.485-502
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• 2015

A computational method for solving singularly perturbed boundary value problem of differential equation with shift arguments of mixed type is presented. When shift arguments are sufficiently small (o(ε)), most of the existing method in the literature used Taylor's expansion to approximate the shift term. This procedure may lead to a bad approximation when the delay argument is of O(ε). The main idea for this work is to deal with constant shift arguments, which are independent of ε. In the present method, we construct the formally asymptotic solution of the problem using the method of composite expansion. The reduced problem is solved numerically by using operator compact implicit method, and the second problem is solved analytically. Error estimate is derived by using the maximum norm. Numerical examples are provided to support the theoretical results and to show the efficiency of the proposed method.

• Proceedings of the Korean Society of Computer Information Conference
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• 2009.01a
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• pp.211-214
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• 2009

Edge detection always influenced by noise belong to the original image, therefore need use some methods to sort this issue, mean shift algorithm has the smooth function which suit for the edge detection purpose, so adopted to fade out the unimportant information, and the sensitive noise portions. After this section, use the Canny algorithm to pick up the contour of the objects we focus on, meanwhile select the Soble operator that has the orientation attribute to support the method work well. In final, take experiment and get the perfect result we wanted, make sure this method make sense and better than the sole Edge detection algorithm,

• Journal of the Korean Society for Precision Engineering
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• v.23 no.12 s.189
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• pp.30-37
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• 2006

In this work, the surface integrity smoothened with a ball end mill was investigated. Because surface integrity mainly affects the manual finishing process, $RV_{AM}$(Remaining Volume After Machining) was introduced, and it gives the relation between machining process and finishing process. Runout and phase shift which adversely affect surface integrity were considered in the generation of surface topography. Cutting points in ball end milling were identified with positional vectors and a set of vectors which have the minimum height in unit area was selected for the generation of surface and $RV_{AM}$. $RV_{AM}$ variation according to runout and phase shift was calculated and experimentally verified in proposed HSM conditions for mold machining. From the simulations and the experiments, a desirable High Speed Machining condition was suggested.

• Journal of the Korean Magnetic Resonance Society
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• v.25 no.1
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• pp.8-11
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• 2021

Transthyretin (TTR) is an important transporter protein for thyroxine (T4) and a holo-retinol protein in human. In its native state, TTR forms a tetrameric complex to construct the hydrophobic binding pocket for T4. On the other hand, this protein is also infamous for its amyloidogenic propensity, which causes various human diseases, such as senile systemic amyloidosis and familial amyloid polyneuropathy/cardiomyopathy. In this work, to investigate various structural features of TTR with solution-state nuclear magnetic resonance (NMR) spectroscopy, we conducted backbone NMR signal assignments. Except the N-terminal two residues and prolines, backbone 1H-15N signals of all residues were successfully assigned with additional chemical shift information of 13CO, 13Cα, and 13Cβ for most residues. The chemical shift information reported here will become an important basis for subsequent structural and functional studies of TTR.

• Journal of Korean Physical Therapy Science
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• v.11 no.3
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• pp.49-59
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• 2004

The purpose of this study was carried out to rind out the prevalence of occupational musculoskeletal disorders among workers in manufacturing industries, so that the result could provide basic data necessary to prevent musculoskeletal disorders. Information on general characteristics, occupational characteristics, and musculoskeletal symptoms were obtained by a self-administered questionnaire between October and November in 2002, from 345 workers in Kim-hae and Ulsan, Kyung-nam province. The data were analyzed for chi-square test by using SPSS NVIN 10.0 program. The results are as follows: According to the self-reports, among musculoskeletal symptoms complain on shoulders are topping for 50.4%, low back is followed for 40.6%, leg/foot 35.7%, neck 34.5%, wrist/hand/finger 30.1%, and arm 24.3%. According to occupational characteristics prevalence by anatomical site, about neck pains 119 subject, occupational satisfaction is 62,6% in moderate group, work shift is 71.8% in no work shift group, each significant high. Symptom complain rate of 104 patients who complained on wrist, hand and finger pain is significantly related that 36.5% below 5 years and 36.5% above 15 years have been worked group. And each of them are significantly related 77.9% in labor workers group, 70% in no work shift group, 54.8% in frequent transfer group. Among 140 subjects who have back pain, that is significationtly reported on 37.1% below 5 years and 37.9% above 15 years and 60.0% moderate satisfied occupation group have been worked group. Therefore, some efforts should be proceeded such as improvement of working condition, flexibility for changing work, more pleasant and better working environment, and etc.

• Journal of Korean Academy of Nursing
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• v.54 no.2
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• pp.139-150
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• 2024

Purpose: This study aimed to identify changes in sleep patterns and fatigue levels during consecutive night shifts among shift nurses and to determine the association between sleep parameters and increased fatigue levels during work. Methods: This prospective observational study employing ecological momentary assessments was conducted using data collected from 98 shift nurses working in Korean hospitals between June 2019 and February 2021. The sleep patterns were recorded using actigraphy. The participants reported their fatigue levels at the beginning and end of each night shift in real time via a mobile link. Linear mixed models were used for the analysis. Results: Nurses spent significantly less time in bed and had shorter sleep durations during consecutive night shifts than on off-duty days, whereas their wake times after sleep onset were much longer on off-duty days than on on-duty days. Fatigue levels were higher on the second and third night-shift days than on the first night-shift days. A shorter time spent in bed and asleep was associated with a greater increase in fatigue levels at the end of the shift than at the beginning. Conclusion: Nurses experience significant sleep deprivation during consecutive night shifts compared with off-duty days, and this sleep shortage is associated with a considerable increase in fatigue levels at the end of shifts. Nurse managers and administrators must ensure sufficient intershift recovery time during consecutive night shifts to increase the time spent in bed and sleeping.

• Journal of the Korean Society of Food Culture
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• v.34 no.4
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• pp.486-494
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• 2019

There are an increasing number of reports that job related factors are associated with hypertension, sleep deprivation, obesity and diabetes. This study analyzed the relationship of working type, working hours and the prevalence of metabolic syndrome. The study's subjects were 2,777 employees (1,446 males and 1,331 females) over 19 years old and their data was from the Korea National Health and Nutrition Survey (2015). The type of work was divided into day work and shift work. The working hours were divided into less than 40 hours, 40 to 49 hours, 50 to 59 hours and 60 hours or more per week. As a result of this study, the prevalence of metabolic syndrome was 26.4% of the males and 19.1% of the females. Generally there was no relationship between metabolic syndrome and type of work (day work and shift work). As a result of analysis of working hours and metabolic syndrome, the workers who worked 40-49 hr were associated with a decreased prevalence of metabolic syndrome as compared to that of workers who worked less than 40 hr (odds ratio: 0.47, 95% confidence interval: 0.24-0.95, p<0.05). Further, positive relationships were found between the number of work hours and the prevalence metabolic syndrome for specific females who worked over 40 hr/wk. It can be concluded from the results that it is important to help workers avoid metabolic syndrome through setting appropriate work hours.

• Journal of muscle and joint health
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• v.25 no.3
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• pp.196-204
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• 2018

Purpose: The purpose of this study was to contribute to the activation of comprehensive nursing care services by comparing and analyzing the working environment and operational status of comprehensive nursing care wards with general wards. Methods: A questionnaire survey was conducted at hospitals operating comprehensive nursing care services. We collected data on patient characteristics, workforce, working environment, and work support facilities of 40 hospitals voluntarily participating in the survey. The collected data were analyzed by dividing it into an comprehensive nursing care ward and a general ward. Results: Compared with the general ward, the comprehensive nursing care ward had fewer hospitalized patients, but the severity of the patients and the need for nursing were high. The number of nurses, assistant nurses, and ward support workers per patient was higher in the comprehensive nursing care ward than in the general ward, and the implementation rate of night shift fixed system, the fixed shift system, and the preceptor system were higher. In terms of structural environment, comprehensive nursing care wards had more room for interviews. Conclusion: The comprehensive nursing care ward had more nursing staff and provided a better working environment than the general ward, but required additional support for the structural environment.

• Safety and Health at Work
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• v.11 no.3
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• pp.361-366
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• 2020

Background: This study aimed to identify the validity of breast cancer symptom questionnaire of worker's special health examination and its relationship with breast ultrasonography findings in young female night workers. Methods: The breast cancer symptom questionnaire data of worker's special health examination and breast ultrasonography results in young female shift workers who worked in one electronic manufacture company were collected from 2014 to 2018. Results: Of the 857 workers, 18 had a Breast Imaging Reporting and Database System category 4 or higher. Among other variables, shift work tenure alone was associated with the risk of having a Breast Imaging Reporting and Database System category higher than 4. The sensitivity, specificity, positive predictive value, and negative predictive value of the symptom questionnaire were 16.7%, 87.7%, 2.8%, and 98.0%, respectively. Conclusion: The current breast cancer symptom questionnaire of the worker's special health examination is inappropriate due to its low sensitivity and positive predictive value. In the future, female night workers will need alternative measures for more accurate screening for breast cancer.