• The Journal of Korean Physical Therapy
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• v.31 no.5
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• pp.322-327
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• 2019

Purpose: This study examined the influence of the maximal aerobic capacity on the two-year cardiac-related re-hospitalization in patients with heart failure with a reduced ejection fraction (HFrEF) in Korean society. Methods: The maximal aerobic capacity of the study population (n=95, male 63%) was evaluated using a cardiopulmonary exercise (CPX) testing system. Each patient was followed up for two years to divide the HFrEF patients into two groups according to cardiac-related re-hospitalization: re-hospitalization (RH) group (n=29, 30%) and no re-hospitalization (NRH) group (n=66, 70%). Results: The relative peak $VO_2$ (mL/kg/min, p<0.001), exercise duration (p<0.001), respiratory exchange ratio ($VCO_2/VO_2$, p=0.001), systolic blood pressure (SBP) reserve (p=0.004), heart rate (HR) reserve (p=0.007), SBP max (p=0.02), and HR max (p=0.039) were significantly lower in the RH group than the NRH group during the CPX test. On the other hand, the ventilatory efficiency (VE/VCO2 slope, p=0.02) and age (p=0.022) were significantly higher in the RH group than in the NRH group. In binary logistic regression analysis, the relative peak $VO_2$ (p=0.001, Wald Chi-square 10.137) was the strongest predictive factor on cardiac-related re-hospitalization, which was followed by $VCO_2/VO_2$ (p=0.019, Wald Chi-square 5.54). On the other hand, age (p=0.063, Wald Chi-square 3.445) did not have a significant influence on cardiac related re-hospitalization. Conclusion: The maximal aerobic capacity, especially the relative peak $VO_2$, is the strongest factor on cardiac-related re-hospitalization within two years in patients with HFrEF in Korean society.

• Journal of the Korean Ceramic Society
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• v.33 no.11
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• pp.1260-1266
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• 1996

The effects of SiO2 MnO2 and sintering atmospheres (O2, N2) on the piezoelectric properties and densification behaviors of Pb0.98Cd0.02Zr0.36Ti0.39Ni0.083Nb0.167O3 were investigated. The addition of SiO2 to the system enhanced the rate of densification but supressed the rate of grain growth. On the other hand the addition of MnO2 to the system did not nearly affect the rate of densification but increased slightly the rate of grain growth The densification of Pb0.98Cd0.02Zr0.36Ti0.39Ni0.083Nb0.167O3 containing of SiO2 or MnO2 was promoted with increasing the partial pressure of O2. The relative dielectric constant ($\varepsilon$r) and piezoelectric constant (d33) of Pb0.98Cd0.02Zr0.36Ti0.39Ni0.083Nb0.167O3 containing of SiO2 or MnO2 sintered under O2 atmosphere were higher than under N2 atmosphere. Whereas the mechanical quality factor (Qm) of specimens sintered under O2 atmosphere were lower than under N2 atmosphere. Thus the sintering atmosphere of O2 and N2 in Pb0.98Cd0.02Zr0.36Ti0.39Ni0.083Nb0.167O3 containing of SiO2 or MnO2 acted as donor and acceptor respectively. As the amount of SiO2 increased the relative dielectric constant ($\varepsilon$r) and piezoelectric constant (d33) of Pb0.98Cd0.02Zr0.36Ti0.39Ni0.083Nb0.167O3 but the mechanical quality factor (Qm) did not nearly change, In the case of the addition of MnO2 to the system the relative dielectric constant ($\varepsilon$r) and piezoelectric constant (d33) of Pb0.98Cd0.02Zr0.36Ti0.39Ni0.083Nb0.167O3 sintered under O2 atmosphere decreased rapidly with increasing the amount of MnO2 but they were unchanged with increasing the amount of MnO2 under N2 sintering atmosphere. Therefore the differences of the relative dielect-ric constant ($\varepsilon$r) and piezoelectric constant (d33) due to sintering atmosphere were diminished as the amount of MnO2 increased.

• Journal of Korea Trade
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• v.26 no.7
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• pp.145-166
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• 2022

Purpose - The field of online videos has seen rapid changes in information and communications technology (ICT) development. Despite active academic research on the use of online platforms, few studies have analyzed the relative importance among the factors determined. In this study, the relative importance of factors found in previous studies was identified for users of online video platforms in China and Korea. Through this, factors that should be considered first in research on online video use were derived. In addition, the quality level of online video platforms currently used in China and Korea was measured and used for analysis. The analysis results can provide information for companies to enter Chinese and Korean markets and also be useful to platform providers aiming to increase usage. Design/methodology - Among the factors of Online Video Usage identified in previous studies, 13 factors to be studied were selected through focus group interviews and hierarchized into 2 layers. For the analytic hierarchy process (AHP), each factor was designed as a pairwise comparison questionnaire. The survey included questions on the quality of online video platform currently in use. Data collection was conducted on 16 platforms in China and 11 platforms in Korea, and the relative importance of factors and user perspectives was compared and analyzed using importance performance analysis (IPA). In the analytical process, platforms were divided into over-the-top (OTT) group and Creator group according to the weight of user-generated content, and data analysis focused on these groups. Findings - As a result of AHP, China and Korea showed both "Fun" and "Interests" factors at the top, while the importance of the Entertainment factor "Vicarious satisfaction" was very different for China and Korea. "Relationship with content creators" was the most important factor in China, but it ranked the lowest in Korea. The IPA showed that the factors with high importance and performance were fun, interests, and easy accessibility for both China and Korea. In contrast, the factors that showed low performance compared to high importance in China were relationship with content creators, relationship with acquaintances/friends, and trustworthiness. As for Korea, vicarious satisfaction was observed; thus, this study has raised the need for academic and industrial interest in vicarious satisfaction. The results show that fun, interests, vicarious satisfaction, and easy accessibility of the platform are factors that must be included in further studies on online videos. Originality/value - Existing studies related to the use of online platforms have derived factors or focused on the influence relationship between factors and performance. However, few studies have analyzed the relative importance among the determined factors. This paper explores factors to be considered in future studies by deriving the relative importance between these factors from the perspective of users in China and Korea.

• Journal of the Korean association of regional geographers
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• v.17 no.4
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• pp.443-458
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• 2011

The purpose of this study is to research space recognition change of the high school students according to geographic information quantities, focused on Factors Influencing the Land Value. The region of case study was some places of Songtan Special Tourism Zone, which responding students were unfamiliar with. The results are as follows. First, through the results of analysing 'the highest valued standard land and choice reasons' in two ㄴregions of the old town and the new town, it is perceived that the relative factor of land is more important than the absolute factor as the factors influencing the land value of the highest valued standard land. Second, there are students' recognition differences in the choice reasons of the highest valued standard land of two regions which have different characteristics. Third, though in the same region, recognitions about factors influencing the land value change according to geographic information quantities, and as students' knowledge about geographic information increases, the choice rate of the highest valued standard land increases. Lastly, it is perceived that there is a facility which has a decisive effect on formating the land value of a certain region.

• Journal of the Ergonomics Society of Korea
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• v.26 no.2
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• pp.45-59
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• 2007

The operating tasks of overhead crane have caused undue stress to the operators from physical, mental, and environmental workload. Existing workload assessment models for musculoskeletal disorders such as OWAS, RULA, and QEC have limited applicability to the crane operating tasks because they focus mainly on physical factors and do not consider the relative importance of each factor. The present study was to develop a workload assessment model customized to overhead crane operation, following a systematic process: (1) analyzing task characteristics, (2) selecting workload factors, (3) developing assessment methods, (4) establishing action levels, and (5) computerizing the assessment model. Based on literature review, worksite survey, and focus group interview, 4 physical factors (awkward posture, static posture, repetitive motion, and excessive force), 6 mental factors (visual demand, auditory demand, task complexity and difficulty, time urgency, work schedule related stress, and safety related stress), and 4 environmental factors (noise, vibration, dust, and temperature) were selected and their rating scales and relative weights were determined. Then, based on the workload assessment results of 8 overhead cranes operated at different workplaces, the action levels of each factor category were established. Finally, the crane operation assessment model was computerized for effective analysis and report preparation. The present approach is applicable to develop a customized workload assessment model for an operating task under consideration.

• Journal of Korea Water Resources Association
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• v.56 no.4
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• pp.285-299
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• 2023

Estimating the evapotranspiration is very important factor for effective water resources management, and FAO Penman-Monteith (FAO P-M) model has been applied for reference evapotranspiration estimation by many researchers. However, because various input data are required for the application of FAO P-M model, understanding the effect of each input data on FAO P-M model is necessary. Therefore, in this study, for 56 study stations located in South Korea, the effects of 8 meteorological factors (maximum and minimum temperature, wind speed, relative humidity, solar radiation, vapor pressure deficit, net radiation, ground heat flux), energy and aerodynamic terms of FAO P-M model, and elevation on FAO P-M reference evapotranspiration (RET) estimation were analyzed. The relative sensitivity analysis was performed to determine how 10% increment of each specific independent variable affects a reference evapotranspiration under given set of condition that other independent variables are unchanged. Furthermore, to select the 5 representative stations and perform the monthly relative sensitivity analysis for those stations, 56 study stations were classified into 5 clusters using cluster analysis. The study results showed that net radiation was turned out to be the most sensitive factor in 8 meteorological factors for 56 study stations. The next most sensitive factor was relative humidity, solar radiation, maximum temperature, vapor pressure deficit and wind speed, followed by minimum temperature in order. Ground heat flux was the least sensitive factor. In case of ground surface condition, elevation showed very low positive relative sensitivity. Relativity sensitivities of energy and aerodynamic terms of FAO P-M model were 0.707 for energy term and 0.293 for aerodynamic term respectively, indicating that energy term was more contributable than aerodynamic term for reference evapotranspiration. The monthly relative sensitivities of meteorological factors showed the seasonal effects, and also the relative sensitivity of elevation showed different pattern each other among study stations. Therefore, for the application of FAO P-M model, the seasonal and regional sensitivity differences of each input variable should be considered.

• Korean Journal of Ichthyology
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• v.32 no.2
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• pp.55-62
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• 2020

The Relative weight index is an index for evaluating nutritional condition of fish by calculating a ratio of observed weight to standard weight. The purpose of this study is estimating standard Length-Weight relationships (standard LWRs) to calculate standard weight for application of relative weight index and analyze frequency distribution of relative weight index of 10 freshwater fish in the South Korea. The standard LWRs for each species was calculated by the Length-Weight data sets from 798 times of captures at 141 sites. The correlation of determination (r²) for all species was over 0.9 and values of parameter b were within the expected range according to Froese (2006). We calculated in increments of 10 from 10 to 90 percentile of relative weight index for each species, and it could be used as a standard for quantitative assessment of nutritional condition of freshwater fish.

• Journal of the Korean Institute of Educational Facilities
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• v.5 no.2
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• pp.49-56
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• 1998

This study aims to estimate the educational environment associated with various learning activities and to compare the differences of each characteristics appeared on the interviews and questions of teachers performing open education. The results were shown to the 5 groups differed from each other by the awareness analysis on their educational environment. According to the analyzed results, firstly, team teaching. applied living factor, unit learning factor, managemental factor, general public factor and assisting managemental factor were influential successively on the degree of satisfaction of teachers to the educational environment in open education of elementary schools. Secondly, to compare the relative differences between the groups, GLM was done. Most factors were significant only in the group of attached school and showed a partial significance in the grade in charge, gender and age.

• Proceedings of the KIEE Conference
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• 2004.11a
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• pp.153-156
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• 2004

An electric power efficiency of electrodeless fluorescent lamp has big relative property of gas in lamp, gas pressure, lamp formation, ingredients of magnetic substance and shape and action frequency etc. We used magnetic substance that open self examination material of electrodeless fluorescent lamp antenna. Ferrite that is used in this experiment was Mn-Zn type. We have examined resistance kind, impedance, Q-factor's frequency characteristic by ferrite. Impedance, resistance and capacitance did not show difference in start frequency 2.65 [MHz] but there was difference quantity. We could know Q-factor's difference according to material, and Q-factor's is important part of antenna design.

• Journal of Digital Convergence
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• v.11 no.1
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• pp.1-11
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• 2013

This study attempt to explore how much characteristics of personal and institutional of staffs in shelter for teenage runaway influence to client's violence, and which factor of them are relative to client's violence. For this aims, we carried out a survey, survey subjects in shelter for teenage runaway participated in this research. T-test and variance analysis attempted to compare degree of violence experience of respondents by personal and institutional characteristics. According to result of analysis, age in the midst of personal characteristics is meaning difference and duty-time and type of shelter in the midst of institutional characteristics revealed meaning difference. Next, Multi-regression analysis tried to explore relative factor influencing on client's violence. The results, age in the midst of personal characteristics is relative with physical violence, duty-year in present institution is relative with etc harm. Also, duty-time per week of institutional characteristics is relative all with four type of violence. Type of shelter is relative with property harm, emotional violence and etc harm. Counseling time during duty is relative with physical violence. Above results provide basic data to find ways preventing client's violence to staffs in shelter for teenage runaway.