• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.1
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• pp.71-77
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• 2018

The optical time domain reflectometer (OTDR) is the most widely used method to monitor problems with currently installed optical fibers. The OTDR is an instrument designed to test the FTTx network and evaluates the physical properties of the fiber, such as transmission loss and connection loss. It is important to improve the spatial resolution in order to accurately grasp the optical path problems by using the OTDR. When the pulse width is less than twice the distance between the two reflectors, the signals reflected from the two reflectors are reflected without overlap, so that the reflected signal can be distinguished. However, when the pulse width is larger than twice the distance between the two reflectors, so that the reflected signal can not be distinguished. In order to overcome these limitations, this paper proposed a method of improving spatial resolution by applying a super resolution algorithm. As a result of the simulation, the resolution is improved when the super resolution algorithm is applied, and the event interval can be analyzed more precisely.

• The Journal of Society for e-Business Studies
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• v.14 no.4
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• pp.59-73
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• 2009

Keyword extraction is an important and essential technique for text mining applications such as information retrieval, text categorization, summarization and topic detection. A set of keywords extracted from a large-scale electronic document data are used for significant features for text mining algorithms and they contribute to improve the performance of document browsing, topic detection, and automated text classification. This paper presents a keyword extraction technique that can be used to detect topics for each news domain from a large document collection of internet news portal sites. Basically, we have used six variants of traditional TF-IDF weighting model. On top of the TF-IDF model, we propose a word filtering technique called 'cross-domain comparison filtering'. To prove effectiveness of our method, we have analyzed usefulness of keywords extracted from Korean news articles and have presented changes of the keywords over time of each news domain.

• Quality Improvement in Health Care
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• v.25 no.2
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• pp.16-25
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• 2019

Purpose:The healthcare system of South Korea is at the extreme of the dispersed system. Few regulations limit patients from directly visiting higher-level medical institutions for primary care sensitive conditions. As a result, similar to local clinics, general and tertiary teaching hospitals also provide diverse primary care services. Our study aimed to examine the general public's perceptions of their primary care performance. Methods: Face-to-face surveys were conducted with 1000 adults who were living in South Korea with the aid of a questionnaire that included the Korean Primary Care Assessment Tool (KPCAT). The KPCAT consists of five domains, which are the main indicators of primary care performance: first contact, comprehensiveness, coordination, personalized care, and family/community orientation. One-way analysis of variance and post hoc tests were used to compare the KPCAT scores across the three types of medical institutions. Results: Domain-wise analyses revealed two different patterns. With regard to first contact and its subdomains, the highest and lowest scores emerged for local clinics and tertiary teaching hospitals, respectively. However, the other four domain scores were significantly lower for local clinics than for the other two types of medical institutions. Conclusions: Local clinics were perceived to be medical institutions that are responsible for providing primary care. However, the general public perceived only one domain of their primary care to be superior to that of the other two types of medical institutions: first contact. National efforts should be taken to strengthen their other four domains of primary care by training their workforce and providing appropriate incentives.

• Journal of Advanced Navigation Technology
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• v.19 no.2
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• pp.161-167
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• 2015

This paper proposed system for providing the national competency standards learning module, which has changed and updated from time to time. The provisioning server of the proposed system provides learning module, and the management server carry out fault management, billing, request management, statistics and aggregate, etc, and the target server requests the learning module in the provisioning server through the domain. The proposed system determines provide of the learning module by CORS based on filter, which is to determine whether matches or not with domain of the provisioning server and the target server. The proposed system can be patch and maintenance remotely about NCS based learning module to be new update and removed. Also, the proposed system may provide contents in conjunction with existing educational systems, and may be extended in the future to enable the management for domain of the target server.

• Journal of The Korea Institute of Healthcare Architecture
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• v.27 no.1
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• pp.17-34
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• 2021

Purpose: The purpose of this study was to find out the difference in the priority level of recognition for universal design application in public spaces by gender. Method: ANOVA(analysis of variance) and post-hoc test were conducted to determine the priority level of recognition and pattern for the disabled, non-disabled, and experts classified into males and females. Results: There was no gender difference in the comparison by sector for all males and females. However, in comparing of domains and facilities, women showed a higher level of recognition than men in the building sector and cross domain. When comparing space consumers and producers by dividing them into male and female groups, women showed a higher level of recognition than men in producers, but there was no gender difference between consumers. In comparison by sector, domain and facility, women producers also showed a higher level of recognition in the road sector, park and recreation sector, sidewalk domain, four-spaces in the park and recreation sector, and six-spaces in the building sector than men producers. Also, in the building sector, women producers and consumers showed a higher recognition level than men. Comparing the disabled, non-disabled people and experts by dividing them into male and female groups, in the case of non-disabled people and experts, women showed a higher level of recognition than men, while men showed a higher level of recognition than women in the disabled. In addition, there were differences in recognition patterns in many spaces and facilities by gender. Implications: This study is meaningful in comparing the differences in the priority level of recognition and patterns between men and women to apply universal design for people of all ages and both sexes.

• Physical Therapy Rehabilitation Science
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• v.11 no.4
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• pp.414-420
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• 2022

Objective: In this study, the test-retest reliability and validity were presented to evaluate the usability of isokinetic rehabilitation equipment for the knee joint. Design: Cross-sectional design, reliability & validity study. Methods: Thirty healthy adults participated in the study. A CSMI dynamometer was used as a standardized measuring device to present the validity of the equipment. It was measured based on the dominant leg. The average peak torque value was selected as the measurement variable. After the measurement, a questionnaire was conducted on safety, satisfaction, and performance through the usability evaluation questionnaire. Results: The knee joint isokinetic rehabilitation equipment showed high reliability with Intraclass Correlations Coefficients (ICC) =0.883~0.956. In order to check the validity of the equipment, the 95% confidence interval of the mean difference limit was confirmed by the Bland & Altman plot. As a result, all three angular velocities showed a smaller confidence interval in the flexion than in extension. There were less than 10 plots that were not included in 2 Standard Deviation (SD) between all measurements. As a result of the usability evaluation questionnaire, the average of the safety domain(4.9±0.4), satisfaction domain(4.1±0.8), performance domain(4.3±0.8). Conclusions: If the product is improved by supplementing the items identified in the usability evaluation process, it is judged that it can be used as a useful device in various knee joint rehabilitation fields.

• Nutrition Research and Practice
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• v.17 no.5
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• pp.945-958
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• 2023

BACKGROUND/OBJECTIVES: Food literacy (FL) is a crucial skill for selecting sustainable and healthy food options, necessitating the identification of vulnerable groups in the community using valid measurement tools. Identifying weak domains in FL is essential for enhancing the overall FL. This study examined the FL levels of Seoul citizens based on their sociodemographic characteristics and assessed the relationship between FL, food intake, and weight status. SUBJECTS/METHODS: This study utilized the data from the Seoul Food Survey, a cross-sectional study employing representative samples of Seoul citizens. Data collection occurred from September to October 2021, with 4,039 citizens aged 18 yrs and above participating in face-to-face surveys. Thirty-three FL items were assessed, comprising 14 items in the nutrition and safety (NS) domain, eight items in the cultural and relational (CR) domain, and 11 items in the socio-ecological (SE) domain. In addition, data on food intake sufficiency and obesity status were collected. The descriptive statistics, t-tests, analysis of variance, and logistic regression analysis were used for analysis. RESULTS: Men, students, young adults, older citizens, and people experiencing food insecurity had the lowest scores for all the FL domains. The highest quartile group of NS scores had a higher probability of consuming adequate servings of vegetables and fruits, with significant linear trends observed (P for trend < 0.05). In all three FL domains, the odds ratio for obesity was significantly lower in the groups with high FL scores (P < 0.05). CONCLUSIONS: A close relationship was observed between low FL, obesity, and food intake, even after controlling for other covariates. Vulnerable groups with low FL were also identified. Therefore, it is essential to develop programs to improve FL and the health and well-being of these groups.

• Nutrition Research and Practice
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• v.18 no.1
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• pp.119-131
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• 2024

BACKGROUND/OBJECTIVES: Happiness is an important factor in life, and food literacy (FL) has been emphasized as a core concept for a happy and healthy life. This study examined the level of happiness of Seoul citizens according to their sociodemographic factors and their association with FL. SUBJECTS/METHODS: This study used the data from the Seoul Food Survey, a cross-sectional study conducted on 4,039 Seoul citizens from September to October 2021. FL was measured using a validated questionnaire consisting of 33 items from 3 sub-domains: 14 items in the nutrition and safety domain, 8 items in the cultural and relational domain, and 11 items in the socio-ecological domain. Statistical analysis involved descriptive statistics and multivariate regression analysis. RESULTS: Various sociodemographic factors, such as household income, subjective health status, and food insecurity, were found to be associated with the level of happiness. The level of FL was also associated with the happiness scores. After adjusting for variables associated with happiness, the participants with the highest quartile FL scores were 7.32 times more likely to respond that they were happy than those with the lowest FL score. Three FL domains and total FL showed linear increases in overall happiness after controlling for subjective health status and sociodemographic factors (P < 0.001). CONCLUSIONS: After adjusting for the related covariates, higher levels of FL were associated with higher scores in happiness. Based on this study, it would be meaningful to evaluate ways to intervene in FL to improve the level of happiness among the general population.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.12
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• pp.1164-1171
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• 2004

A new multi-scale simulation model is proposed to analyze heart mechanics. Electrophysiology of a cardiac cell is numerically approximated using the previous model of human ventricular myocyte. The ion transports across cell membrane initiated by action potential induce an excitation-contraction mechanism in the cell via cross bridge dynamics. Negroni and Lascano model (NL model) is employed to calculate the tension of cross bridge which is closely related to the ion dynamics in cytoplasm. To convert the tension on cell level into contraction force of cardiac muscle, we introduce a simple geometric model of ventricle with a thin-walled hemispheric shape. It is assumed that cardiac tissue is composed of a set of cardiac myocytes and its orientation on the hemispheric surface of ventricle remains constant everywhere in the domain. Application of Laplace law to the ventricle model enables us to determine the ventricular pressure that induces blood circulation in a body. A lumped parameter model with 7 compartments is utilized to describe the systemic circulation interacting with the cardiac cell mechanism via NL model and Laplace law. Numerical simulation shows that the ion transports in cell level eventually generate blood hemodynamics on system level via cross bridge dynamics and Laplace law. Computational results using the present multi-scale model are well compared with the existing ones. Especially it is shown that the typical characteristics of heart mechanics, such as pressure volume relation, stroke volume and ejection fraction, can be generated by the present multi-scale cardiovascular model, covering from cardiac cells to circulation system.

• Smart Structures and Systems
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• v.19 no.2
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• pp.181-194
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• 2017

In order to investigate the interface debonding defects detection mechanism between steel tube and concrete core of concrete-filled steel tubes (CFSTs), multi-physical fields coupling finite element models constituted of a surface mounted Piezoceramic Lead Zirconate Titanate (PZT) actuator, an embedded PZT sensor and a circular cross section of CFST column are established. The stress wave initiation and propagation induced by the PZT actuator under sinusoidal and sweep frequency excitations are simulated with a two dimensional (2D) plain strain analysis and the difference of stress wave fields close to the interface debonding defect and within the cross section of the CFST members without and with debonding defects are compared in time domain. The linearity and stability of the embedded PZT response under sinusoidal signals with different frequencies and amplitudes are validated. The relationship between the amplitudes of stress wave and the measurement distances in a healthy CFST cross section is also studied. Meanwhile, the responses of PZT sensor under both sinusoidal and sweep frequency excitations are compared and the influence of debonding defect depth and length on the output voltage is also illustrated. The results show the output voltage signal amplitude and head wave arriving time are affected significantly by debonding defects. Moreover, the measurement of PZT sensor is sensitive to the initiation of interface debonding defects. Furthermore, wavelet packet analysis on the voltage signal under sweep frequency excitations is carried out and a normalized wavelet packet energy index (NWPEI) is defined to identify the interfacial debonding. The value of NWPEI attenuates with the increase in the dimension of debonding defects. The results help understand the debonding defects detection mechanism for circular CFST members with PZT technique.