• Sleep Medicine and Psychophysiology
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• v.13 no.2
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• pp.52-58
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• 2006

Objectives: Continuous positive airway pressure (CPAP) is effective in the treatment of obstructive sleep apnea syndrome (OSAS), but the major limitation of CPAP may be poor compliance. The aims of the study were to investigate the compliance and side effects of CPAP, and to evaluate the efficacy of CPAP in patients with OSAS. Methods: This study enrolled 106 patients with OSAS who took the CPAP treatment. The severity of daytime sleepiness was measured using Epworth Sleepiness Scale (ESS), and sleep quality and depressive symptoms were assessed by Pittsburgh Sleep Quality Index (PSQI) and Beck Depression Inventory (BDI), respectively. Results: During 29 months of the study period, 41.5% of patients were using CPAP and 38.7% of patients stopped using it. Compared to non-compliant patients, compliant patients had a higher PSQI score and obstructive apnea index. Among non-compliant patients, 51.2% of them stopped using CPAP within 1months. 85.7% of non-compliant patients were discomforted by the CPAP, but much more nasopharyngeal symptoms were reported in the compliant group. ESS (p<0.01), PSQI (p<0.01) and BMI (p<0.01) were reduced significantly after CPAP treatment but not BDI (p=0.86). Conclusions: We concluded that CPAP can reduce the daytime sleepiness, nocturnal sleep disturbance, and body mass index. To increase the compliance of CPAP, we suggest that some education and support are needed at the early stage of the CPAP treatment.

• Journal of the Korean Geographical Society
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• v.36 no.5
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• pp.578-592
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• 2001

Based on a survey sample of farm households in three provinces of Korea, this article reports the perspectives of fuel-time farmers regarding trade liberalization, its effects on their lives, and the future of small-scale farming. While the agricultural sector is being transformed under neoliberal policies, farmers, with life or no preparation for a global market order, are forced to modernize their farming operations. The findings from the survey indicate that farmers accede to terms of global integration in principle while disapproving state rural policies in practice. The survey data also confirm that intra-regional differences in farmers'perceived satisfaction with living conditions, government farm policies, and socio-economic/labor issues. Disparities in the degree of discontent with government policies and socio-economic well-being are explicit between the relatively diversified region of Kyonggi Province and the farming-dependent regions of Chunbuk and Kyongbuk Provinces. The overall findings uphold that most farmers who have not been fully exposed to free market mechanisms are confronted by increased uncertainties and economic hardships. The findings propound that agricultural/rural policies need to reflect long-term, macroeconomic changes, and regionally/locally-based agricultural structure.

• Journal of the Korean Geotechnical Society
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• v.20 no.9
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• pp.105-114
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• 2004

Consolidation characteristics have been investigated by using Rowe cell consolidation tester for dredged soil, which is more than two times as much as the liquid limit. To examine the effects of variation of water content on consolidation characteristic, tests were carried out varying the initial water content from $100\%\;to\;150\%.$ The results were compared with the consolidation characteristics of remolded clay. The test results showed that the hither the initial water content of dredged clay was, the more noticeable the non-linear behavior of e-log P curves occurred. The variation of the gradient was apparent to load stage 40kPa and became less apparent after load stage 80kPa on the e-log P curves. Ratio of compression index stayed within the range suggested by Mesri and variation of initial water content has hardly influenced the coefficient of consolidation. On the contrary, it was found that the magnitude of consolidation load affects the vertical coefficient of consolidation. The variation of stratum thickness during consolidation processing needs to be taken into consideration since hydraulic fill would go through a much larger scale strain than land soil when it is subject to a load. In this study, the consolidation period considering the variation of stratum thickness was analyzed and the results were compared with those of existing consolidation studies which did not consider the variation of stratum thickness. According to the results of the study, the consolidation period of the ground with a larger strain was calculated more close to observed value in case of Mikasa theory which takes the variation of stratum thickness into consideration.

• Korea Journal of Hospital Management
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• v.22 no.3
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• pp.61-73
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• 2017

Purposes : The purpose of this study is to identify factors that have effects on safety activities of hospital personnels by investigating causality between patient safety culture, job stress, safety system and safety activities of faculty and staff member who are working for oriental medicine hospital of university. Methodology : The subjects were 246 employees working in 4 oriental medicine hospitals of university in Daejeon and Chungcheongnam-do. The data were collected from January 16 to January 25, 2017 using a structured questionnaire. For data analysis, descriptive statistics, Pearson correlation coefficient, t-test, ANOVA and Duncan test with SPSS 22.0 were used. Findings : The activity score for patient safety of faculty and staff member, who were experienced at job training program after joining a company and regular training course for qualification or license, was meaningfully higher than that of group who had no job training experience. The result indicated that the higher there is level of safety culture and safety system and the lower there is work stress, the more the activity has positive effect on patient safety. The level score of awareness for safety culture of faculty and staff member in C hospital, which is facing financial crisis in business circumstances recently, showed average value of 3.29. It was significantly lower than that of the other three hospital. Also, The activity score for patient safety was markedly lower than that of the other three hospital. This result become interested in the process of linking non-financial performance and financial performance. The level score of safety activity in A hospital which obtained healthcare accreditation was remarkably higher than that of the other three hospital which didn't certify healthcare accreditation. Pratical Implications : Subjects about Q.I or patient's experience management must be included in curriculum of Oriental medicine. It is necessary to get the effect of job training program for faculty and staff member through the process of preparation for obtaining healthcare accreditation. When the hospital director is appointed, it must be considered that he/she has the ability to attach importance to analysis and management of the factors creating safety accident, and has business mindset for healthcare delivery of customer- centricity. This research showed that financial performance of hospital, which of business environment is favorable; located in metropolitan city and having large scale of hospital and quality of residence rating but low-level of safety culture and safety activity, was lower than that of general hospital situated in small and medium-sized cities. More research needs to be done for answering this result.

• Korean Chemical Engineering Research
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• v.49 no.6
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• pp.790-797
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• 2011

Hydrodynamic similarity was analyzed by employing scaling factor in three phase fluidized beds. The scaling factor was defined based on the holdups of gas, liquid and solid particles and effectivity volumetric flux of fluids between the two kinds of fluidized beds with different column diameter. The column diameter of one was 0.102 m and that of the other was 0.152 m. Filtered compressed air, tap water and glass bead of which density was 2,500 kg/$m^3$ were used as gas, liquid and solid phases, respectively. The individual phase holdups in three phase fluidized beds were determined by means of static pressure drop method. Effects of gas and liquid velocities and particle size on the scaling factors based on the holdups of each phase and effective volumetric flux of fluids were examined. The deviation of gas holdup between the two kinds of three phase fluidized beds decreased with increasing gas or liquid velocity but increased with increasing fluidized particle size. The deviation of liquid holdup between the two fluidized beds decreased with increasing gas or liquid velocity or size of fluidized solid particles. The deviation of solid holdup between the two fluidized beds increased with increasing gas velocity or particle size, however, decreased with increasing liquid velocity. The deviation of effective volumetric flux of fluids between the two fluidized beds decreased with increasing gas velocity or particle size, but increased with increasing liquid velocity. The scaling factor, which was defined in this study, could be effectively used to analyze the hydrodynamic similarity in three phase fluidized processes.

• Korean Chemical Engineering Research
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• v.43 no.2
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• pp.286-293
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• 2005

An interpretation on the solid circulation characteristics in a fluidized-bed process has been carried out as a first step to simulate the dry entrained-bed absorption and bubbling-bed regeneration system for $CO_2$ removal from flue gas. A particle population balance has been developed to determine the solid flow rates and particle size distributions in the process. Effects of principal process parameters have been discussed in a laboratory scale process (absorption column: 25 mm i.d., 6 m in height; regeneration column: 0.1 m i.d., 1.2 m in height). The particle size distributions in absorption and regeneration columns were nearly the same. As gas velocity or static bed height in the absorption column increased, soild circulation rate and feed rate of fresh sorbent increased, however, mean particle diameter decreased in the absorption column. As cut diameter of the cyclone of the absorption column increased, solid circulation rate decreased, whereas feed rate of fresh sorbent and mean particle diameter in the absorption column increased. As attrition coefficient of sorbent particle increased, solid circulation rate and feed rate of fresh sorbent increased but mean particle diameter in the absorption column decreased.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.106-111
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• 2008

Polypropylene (PP)/corn starch master batch (starch-MB)/silicate composites with different corn starch compositions of 10, 20, 30, 40 and 50 were prepared by melt compounding at $200^{\circ}C$, using lab scale Brabender mixer. The content of silicate was fixed at 5 wt%. The composition of starch-MB in composites was confirmed by the existence of hydroxy group and peak intensity in fourier-transform-infrared (FT-IR) spectrum. The thermal properties of the PP/starch-MB/silicate composites were investigated by differential scanning calorimetry (DSC), and thermogravimetric analyzer (TGA). There was no district change in melting temperature, and TGA curve indicates a decrease in degradation temperature with the increase of starch-MB content. The silicate dispersion of the composites was measured by X-ray diffraction (XRD) and transmission electron microscope (TEM). The degree of silicate dispersion in PP/starch-MB/silicate composites depended on the content of starch-MB. There was detectable change in d-spacing and peak intensity of the composite when the content of starch-MB was higher than 20 wt%. The rheological behavior of the composites was explained by both shear thinning effect and elastic property with the starch-MB amount. These effects were remarkable when the content of starch-MB was higher than 20 wt%. These were confirmed by an oscillatory viscometer at $200^{\circ}C$.

• Management & Information Systems Review
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• v.35 no.2
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• pp.45-66
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• 2016

Firms can make scale of economy and scope of economy by internalizing and using new advanced technology and knowledge from technology cooperation network, decrease risk and cost with partner firm of technology cooperation network, and increase market advantage of product & strengthen firms' position in the market. Due to the advantages of technology cooperation network, the related studies have focused on the positive effect of technology cooperation network. However, the related studies investigating the relationship between technology cooperation network and firm performance have only examined the role of technology cooperation network. Safeguarding mechanism, relationship learning, and relationship performance are categorized into the process of technology cooperation network, and this categorization is applied as resources, capability, and performance by resource based view. The empirical results are reported as belows. First, relationship specific investment and relationship capital positively affect on relationship learning as capability. Second, information sharing, common information understanding, and relationship specific memory development positively affect on long-term orientation, but information sharing has no impact on efficiency and effectiveness. Third, relationship specific investment positively affects on relationship capital and efficiency and effectiveness have positive effects on long-term orientation. Applying technology cooperation network in asymmetric technology dependency with resource based theory, this study suggested the importance of both safeguarding and relationship learning by investigating the relationship among safeguarding, relationship learning, and relationship performance. And it is worthy that this study investigated how firms' behavior change affects relationship performance in the relationship of technology cooperation partner.

• Journal of Digital Convergence
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• v.18 no.10
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• pp.547-555
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• 2020

To investigate the effects of self-management programs for chronic low back pain (LBP), 63 subjects were assigned to three groups; self-exercise group (SEG), hot pack and low-frequency electrical stimulation group (HEG), and thermo-massage group (TMG). Parameters were the pain numeric rating scale (PNRS), Oswestry Disability Index (ODI), Roland Morris Disability Questionnaire (RMDQ) and Relapse frequency (RF). PNRS, ODI and RMDQ of SEG and TMG sustained effectiveness, however, PNRS, which improved after treatment in HEG, worsened in 6 month. Between the groups, all parameters were better in SEG and TMG compare to HEG. Exercise and thermo-massage can be considered as useful self-management performed at home to prevent the relapse of chronic LBP.

• Ocean Systems Engineering
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• v.6 no.1
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• pp.23-60
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• 2016

The major objective of this study was to develop further understanding of 3D nearshore hydrodynamics under a variety of wave and tidal forcing conditions. The main tool used was a comprehensive 3D numerical model - combining the flow module of Delft3D with the WAVE solver of XBeach - of nearshore hydro- and morphodynamics that can simulate flow, sediment transport, and morphological evolution. Surf-swash zone hydrodynamics were modeled using the 3D Navier-Stokes equations, combined with various turbulence models (${\kappa}-{\varepsilon}$, ${\kappa}-L$, ATM and H-LES). Sediment transport and resulting foreshore profile changes were approximated using different sediment transport relations that consider both bed- and suspended-load transport of non-cohesive sediments. The numerical set-up was tested against field data, with good agreement found. Different numerical experiments under a range of bed characteristics and incident wave and tidal conditions were run to test the model's capability to reproduce 3D flow, wave propagation, sediment transport and morphodynamics in the nearshore at the field scale. The results were interpreted according to existing understanding of surf and swash zone processes. Our numerical experiments confirm that the angle between the crest line of the approaching wave and the shoreline defines the direction and strength of the longshore current, while the longshore current velocity varies across the nearshore zone. The model simulates the undertow, hydraulic cell and rip-current patterns generated by radiation stresses and longshore variability in wave heights. Numerical results show that a non-uniform seabed is crucial for generation of rip currents in the nearshore (when bed slope is uniform, rips are not generated). Increasing the wave height increases the peaks of eddy viscosity and TKE (turbulent kinetic energy), while increasing the tidal amplitude reduces these peaks. Wave and tide interaction has most striking effects on the foreshore profile with the formation of the intertidal bar. High values of eddy viscosity, TKE and wave set-up are spread offshore for coarser grain sizes. Beach profile steepness modifies the nearshore circulation pattern, significantly enhancing the vertical component of the flow. The local recirculation within the longshore current in the inshore region causes a transient offshore shift and strengthening of the longshore current. Overall, the analysis shows that, with reasonable hypotheses, it is possible to simulate the nearshore hydrodynamics subjected to oceanic forcing, consistent with existing understanding of this area. Part II of this work presents 3D nearshore morphodynamics induced by the tides and waves.