• Macromolecular Research
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• 제17권11호
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• pp.886-893
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• 2009

Surface modifications using a radio frequency Ar-plasma treatment were performed on a polypropylene (PP) blend used for automotive bumper fascia. The surface characterization and morphology were examined. With increasing aging time, there was an increase in wettability, oxygen containing polar functional groups (i.e., C-O, C=O and O-C=O) due to oxidation, the amount of tale, and bearing depth and roughness on the PP surface, while there was a decrease in the number of hydrocarbon groups (i.e., C-C and C-H). AFM indicated that the Ar-plasma-treatment on a PP blend surface transforms the wholly annular surface into a locally dimpled surface, leading to an improvement in wettability. SEM showed that the PP layer observed in the non-plasma-treated sample was removed after the Ar-plasma treatment and the rubber particles were exposed to the surface. The observed surface characterization and morphologies are responsible for the improved wettability and interfacial adhesion between the PP blend substrate and bumper coating layers.

• Geomechanics and Engineering
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• 제29권3호
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• pp.369-376
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• 2022

Accurately evaluating and predicting the performance of facilities is a key task in establishing a maintenance strategy for facilities. The importance of performance evaluation is becoming more pronounced, especially when the aging of facilities requires a huge budget. In this study, performance assessment models were developed for road and railway tunnels. Delphi analysis was performed to identify sub-elements necessary to evaluate the performance of a tunnel. The relative importance of the evaluation factors was derived from the AHP analysis. The correlation analysis was performed between each assessment factor and the final result to verify the significance of the model. For the correlation analysis, the survey data measured through precision safety diagnosis in tunnels in use was applied. The cost effectiveness analysis was also conducted according to the scenarios with different composition of performance factors in order to improve the practical applicability of the evaluation model developed in this study.

• 한국콘텐츠학회논문지
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• 제18권5호
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• pp.156-166
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• 2018

최근 고령화로 인해 복지기술(Welfare Technology)의 개발욕구 및 사용 필요성은 사회적으로 증대하고 있으나 새롭게 개발된 복지기술의 개인적 사회적 경제적 영향에 대한 평가논의는 부족한 실정이다. 따라서 본 연구는 복지기술에 대한 개념과 기술영향평가의 이론적 내용들을 분석하여 고령층을 위한 복지기술영향 평가에 적용할 수 있는 지표개발에 대한 논의를 하는 것을 목적으로 하고 있다. 이를 위해 일반기술과 구별되는 복지기술 대상자의 특징을 살펴보고 복지기술의 개념정립과 이론적 고찰을 시도하였다. 또한 기존 기술영향평가지표와 복지기술관련 연구결과를 분석하여 고령층을 위한 복지기술영향평가 지표들을 도출하였다. 평가지표들은 개인적, 경제적, 사회적, 과학기술적, 환경적, 윤리적 측면 등 총 6개 분야별로 제시되었으며, 사례연구를 위해 2개의 고령층대상 복지기술제품의 영향평가에 적용 활용하였다. 본 연구에서 도출된 고령층대상 복지기술영향평가지표들은 복지기술의 수혜자인 고령층 또는 돌봄제공자들이 중요한 이해관계자로서 참여하여 복지기술영향평가의 실효성을 증대시키는데 중점을 두었다.

• International Journal of Concrete Structures and Materials
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• 제11권2호
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• pp.199-213
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• 2017

Chloride penetration is among the main causes of corrosion initiation in reinforced concrete (RC) structures producing premature degradations. Weather and exposure conditions directly affect chloride ingress mechanisms and therefore the operational service life and safety of RC structures. Consequently, comprehensive chloride ingress models are useful tools to estimate corrosion initiation risks and minimize maintenance costs for RC structures placed under chloride-contaminated environments. This paper first presents a coupled thermo-hydro-chemical model for predicting chloride penetration into concrete that accounts for realistic weather conditions. This complete numerical model takes into account multiple factors affecting chloride ingress such as diffusion, convection, chloride binding, ionic interaction, and concrete aging. Since the complete model could be computationally expensive for long-term assessment, this study also proposes model simplifications in order to reduce the computational cost. Long-term chloride assessments of complete and reduced models are compared for three locations in France (Brest, Strasbourg and Nice) characterized by different weather and exposure conditions (tidal zone, de-icing salts and salt spray). The comparative study indicates that the reduced model is computationally efficient and accurate for long-term chloride ingress modeling in comparison to the complete one. Given that long-term assessment requires larger climate databases, this research also studies how climate models may affect chloride ingress assessment. The results indicate that the selection of climate models as well as the considered training periods introduce significant errors for mid- and long- term chloride ingress assessment.

• Smart Structures and Systems
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• 제19권2호
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• pp.225-236
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• 2017

Railroad bridges in North America are an integral but aging part of the railroad network and are typically only monitored using visual inspections. When quantitative information is required for assessment, railroads often monitor bridges using accelerometers. However without a sensor to directly measure displacements, it is difficult to interpret these results as they relate to bridge performance. Digital Image Correlation (DIC) is a non-contact sensor technology capable of directly measuring the displacement of any visible bridge component. In this research, a railroad bridge was monitored under load using DIC and accelerometers. DIC measurements are directly compared to serviceability limits and it is observed that the bridge is compliant. The accelerometer data is also used to calculate displacements which are compared to the DIC measurements to assess the accuracy of the accelerometer measurements. These measurements compared well for zero-mean lateral data, providing measurement redundancy and validation. The lateral displacements from both the accelerometers and DIC at the supports were then used to determine the source of lateral displacements within the support system.

• 대한간호학회지
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• 제30권4호
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• pp.932-947
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• 2000

The purpose of this study was to suggest directions for developing a Health Promotion Program for the elderly in Korea for the future. For this, twenty previously developed & implemented health promotion programs were reviewed and analyzed in terms of target population of the program, components of the program, measurement variables for effects of program, the effects of the program. The results were as follows. 1. Most of the target populations were older adults living independently in the community. 2. Components of the program were health education, health assessment and counseling and exercise program. - Health education was done in most of programs. The topics of health education that were often included in the programs were life style changes, medical knowledge, independent living, the concept of health promotion and changes related to aging. - In health assessment and counseling, health professionals discovered their health problems through health assessment or health risk appraisal. Then they developed health recommendations on each health problem and encouraged the elderly to implement the recommendations. 3. Variables measuring the direct effects of the program were health behavior, knowledge, attitude, skill, use of medical/health reference book. Variables measuring the indirect effects, biometric outcome, health status, functional status, medical service utilization, medical cost and wellbeing. 4. The analysis showed that health education was effective for changing health behaviors, improving knowledge, skill and attitude in the elderly. Those results were suggested to be used as guidelines for developing a health promotion program for the elderly in Korea for the future.

• 대한간호학회지
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• 제27권3호
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• pp.601-613
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• 1997

This project was conducted using a survey method and through interviewing with four persons aged 60 years and over. An interview with an open-ended questionnaire was also used for elderly persons, families, oriental medicine doctor and nurses. topic-related literature review was also done. In total, 382 statements were derived. For content validity, nursing professionals were involved in this study, From that 48 items are developed. The subjects were 340 elderly persons over 60 years old. Data were collected duicing February and March 1997 and analyzed using the SPSS package The result are as follows. 1. Items with low Cronbach Coefficient alpha which means low correlation with total items were removed. 2. Factor analysis was done in order to confirm construct validity and eight factors were obtained from the results. The first factor, 'positive cognition of the aging process', the second factor, 'relationship network' the third factor, 'maintanence of physical functioning, the fourth factor', 'maintanence of peaceful mind' the fifth factor, 'keeping up with daily tasks' the sixth factor, 'continuous adequate body movement' the seventh factor,'involvement of religion in the elderly person's life and the eight factor', 'appropriate resting'. Cronbach Coefficient alpha for the 33 items was .9127 Based on the result, the following is suggested 1. It is anrticipated that the fundamental health of elderly person could be promoted by assessing healthy behaviors of elderly person with this assessment tool. 2. Further studies could be derived from this research. 3. Validity of this assessment tool should be further tested with and a larger sample of elderly person including in-patient elderly persons as well as nursing home residents.

• 조명전기설비학회논문지
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• 제27권9호
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• pp.83-89
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• 2013

Power distribution system has been changed from radial system to closed loop or mesh system due to connection of distributed generation growth. Data from distribution equipments which are installed at distribution line is required to be accurate for the performance of DMS(Distribution Management System). This paper analyzes the voltage measurement data from distribution equipment. However, the results of the analysis are confirmed to have some errors in voltage measurement data from distribution equipment. These errors come from aging of voltage sensor in distribution equipment and inaccurate data transfer to FRTU(feeder remote terminal unit) through the controller. The main problem is that the voltage measurement data of distribution equipment can not be assessed after it's first installation at the distribution line. The voltage measurement accuracy assessment system is to assess the voltage measurement data from distribution equipment on hot-line. This study had a field test to verify the performance of system.

• 치위생과학회지
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• 제22권2호
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• pp.67-74
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• 2022

Background: Depression and cognitive function have a positive effect on the improvement of quality of life and extension of lifespan in the elderly. In addition, it appears as a major factor influencing oral health status. Therefore, this study looked at the relationship between the Geriatric Oral Health Assessment Index (GOHAI), depression, and cognitive function in the elderly using the Korea Longitudinal Study of Aging. Methods: In this study, 4,535 elderly people aged 65 years and over were targeted using the 7th data of the 2018 Korea Longitudinal Study of Aging. A t-test and ANOVA analysis were performed to compare GOHAI, depression, and cognitive function by group. In addition, hierarchical multiple linear regression was performed to understand the effect of the elderly's perceived depression scale and cognitive ability on GOHAI. Results: As a result of adding the depression scale and cognitive function variables to Model 2, the explanatory power was 22%. Educational level, marital status, private health insurance subscription, average monthly allowance, subjective health status, use of dentures, smoking status, economic activity, depression scale, and cognitive function were found to have significant influence (p<0.05). In addition, when controlled and viewed with all factors, depression and cognitive function were found to have an effect on oral health-related quality of life. Conclusion: The findings indicate that depression and cognitive function are associated with oral health-related quality of life in the Korean elderly. As the age increases, the quality of life declines due to depression and cognitive function problems, in addition to oral discomfort, eating disorders, and physical discomfort.

• 대한간호학회지
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• 제53권4호
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• pp.371-384
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• 2023

Purpose: With an increase in the aging population, the number of patients with degenerative spinal diseases undergoing surgery has risen, as has the incidence of postoperative delirium. This study aimed to investigate the risk factors affecting postoperative delirium in older adults who had undergone spine surgery and to identify the associated biomarkers. Methods: This study is a prospective study. Data of 100 patients aged ≥ 70 years who underwent spinal surgery were analyzed. Demographic data, medical history, clinical characteristics, cognitive function, depression symptoms, functional status, frailty, and nutritional status were investigated to identify the risk factors for delirium. The Confusion Assessment Method, Delirium Rating Scale-R-98, and Nursing Delirium Scale were also used for diagnosing delirium. To discover the biomarkers, urine extracellular vesicles (EVs) were analyzed for tau, ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), neurofilament light, and glial fibrillary acidic protein using digital immunoassay technology. Results: Nine patients were excluded, and data obtained from the remaining 91 were analyzed. Among them, 18 (19.8%) developed delirium. Differences were observed between participants with and without delirium in the contexts of a history of mental disorder and use of benzodiazepines (p = .005 and p = .026, respectively). Tau and UCH-L1-concentrations of urine EVs-were comparatively higher in participants with severe delirium than that in participants without delirium (p = .002 and p = .001, respectively). Conclusion: These findings can assist clinicians in accurately identifying the risk factors before surgery, classifying high-risk patients, and predicting and detecting delirium in older patients. Moreover, urine EV analysis revealed that postoperative delirium following spinal surgery is most likely associated with brain damage.