• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.4
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• pp.728-733
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• 2011

This study was designed to analyze the results of stress index by heart rate variability test. The subjects were workers in the automobile manufacturing industry. The subjects consisted of 23,767 workers who had answered about questionnaires of a job position, age, smoking, drinking, exercise state and sex. The stress index(SI) and stress resistance(SR) were examined by SA3000P. We analyzed the differences of SI and SR according to job positions, ages, the state of smoking, drinking, exercise and sex by T-test or ANOVA with SPSS ver. 17.0. Regarding the differences of SI among job positions, the SI was highest in sales positions. Among ages, the SI was highest in 30s. In smoking, the SI was lower in non-smoking group. In drinking, there was no significant differences in SI. In exercise, the SI was lower in exercise group. In sex, there was no significant difference. The case of SR, SR was lowest in sales positions. Among ages, the SR was lowest in 40s. In smoking, the SR was lower in smoking group. In drinking, there was no significant differences in SR. In exercise, there was no significant difference. In sex, the SR was lowest in male. According to these results, we should establish the methods of controlling stress from the perspective of Korean traditional medicine.

• Journal of the Korean Ceramic Society
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• v.31 no.2
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• pp.206-212
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• 1994

Effects of the film deposition process parameters on the properties such as deposition rate, etch rate, refractive index, stress and step coverage of plasma enhanced chemical vapor deposited (PECVD) tetraethylorthosilicate glass (TEOS) SiO2 film were investigated and analysed using SEM, FTIR and SIMS techniques. Increasing TEOS flow or decreasing O2 flow increased the deposition rate and the compressive stress of the oxide film but produced a less denser film. The deposition rate decreased owing to the decrease in the sticking coefficient of the TEOS and the O2 molecules onto the substrate Si with increasing the substrate temperature. Increasing the substrate temperature produced a denser film with a lower etch rate and the higher refractive index by lowering SiOH and moisture contents. Increasing the rf power increases the ion bombardment energy. This increase in energy, in turn, increases the deposition rate and tends to make the film denser. No appreciable changes were found in the deposition rate but the refractive index and the stress of the film decreased with increasing the deposition pressure. The carbon content in the plasma TEOS CVD oxide film prepared under our standard deposition conditions were very low according to the SIMS analysis results.

• Korean Journal of Materials Research
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• v.7 no.2
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• pp.102-106
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• 1997

Micro gas sensors including thin film catal) tic type require stress-free memhrancs for etch stop of Si anisotropic etching and sublayer of sensing elements hecause stress is one of the main factors affecting breakdown of thin membranes. This paper reports the effects of deposition conditions on stress and refractive index of $SiN_{x}/SiO_{x}/(NON)$ films deposited by low pressure c11ernic;rl vapor deposition(L, t'CVI)) 2nd reactve sputtering. In the case of I.PCVI1, the stresses of $SiN_{x}$ and NON films arc $7.6{\times}10^{8}dyne/cm^2$ and $3.3{\times}10^{8}dyne/cm^2$, respectibely, and the refractive indices are 3.05 and 152, respectively. In the cxse oi the sputtered SiN, , compressi\e stress decreased in magnitude and then turned to tensility as increasing proc, ess pressure by lmtorr to 30mtorr and cicreasmg applied power density by $2.74W/cm^2$ to $1.10W/cm^2$. The hest value of film stress obt;~ined under condition of lOmtorr and $1.37W/cm^2$ in this' experiment was $1.2{\times}10^{9}dyne/cm^2$ cnnipressive. The refr~ict~ve index decreased from 2 05 to 1 89 as decreasing applied power density by lnitorr to 3Orntorr and increasing process pressure hy $2.74W/cm^2$ to $1.10W/cm^2$. Stresses of films deposited by both LPCVL) and sputtering decreased as incre;lsing temperature and showed plastic behavior as decreasing temperature.

• Biomedical Science Letters
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• v.18 no.4
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• pp.384-390
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• 2012

Diabetes mellitus (DM) is considered to be a serious metabolic disease which may cause systemic complications. The present study was designed to clarify a difference on stress, physiological variables and their correlation between diabetic (DM group) and nondiabetic adults (control group). The levels of body weight, waist circumference, blood pressure, body mass index, body fat mass, total cholesterol (TcH), triglyceride (TG), aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), total bilirubin (TB), autonomic balance (AB), stress index (SI), fatigue index (FI), and heart rate (HR) were all significantly higher in the DM group than in the control group. However, the levels of autonomic activity (AA), stress resistance (SR), and electrocardiac stability (ES) were significantly lower in the DM group than in the control group. The percentages of persons with abnormal levels in the Tch, high density lipoprotein, low density lipoprotein, TG, AST, ALT and GGT were significantly greater in the DM group than in the control group. In the correlation of glucose and hemoglobin A1c (HBA1c) to stress indices, the DM group had a significant relationship with AB, SR, SI, FI, ES, and HR, whereas the control group had no significant relationship with these, excepting AB. These results suggest that DM was harmfully associated with body, biochemical and stress indices and that blood glucose and HBA1c levels must be exhaustively regulated.

• Journal of the Korean Society of Radiology
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• v.16 no.5
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• pp.545-551
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• 2022

This study analyzed the correlation between stress measurements calculated through HRV signals and thyroid function test items. 181 healthy adults without disease who visited Clinic K were the subjects of this study. Stress resistance (SR) and stress index (SI) were calculated using the acquired HRV signal, and TSH, Free T4, and T3 were used as thyroid function test items. For the measured values, the relationship between each item was statistically analyzed through Pearson correlation analysis. From the results, it was confirmed that Free T4 and SR had a positive correlation (r=0.18) and a negative correlation with SI (r=-0.16). Through this, it was confirmed that there is a significant relationship between thyroid function and HRV signal.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.4 no.1
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• pp.71-75
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• 1994

In this study, a thermoelastic stress index of (100) oriented single crystalline silicon wafer and a relationship between thermal stress and critical plastic deformation temperatures were simulated. The simulated results for the thermoelastic stress index indicated a maximum value on <110> direction and a minimum on <100>. Then, it could be predicted that silicon wafer is plastically deformable over 1000 K, based on the relationship between the thermal stress derived from the thermoelastic stress index and the critical plastic deformation temperature.

• Journal of the Korean Vacuum Society
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• v.6 no.S1
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• pp.75-79
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• 1997

Optical and mechanical characteristics of $TiO-2, ZrO_2 \;and\; SiO_xN_y$ thin films prepared by ion assisted deposition (IAD) were investigated. IAD films were bombarded by Ar or nitrogen ion beam from a Kaufman ion source while they were grown in as e-beam evaporator. The result shows that the Ae IAD increases the refractive index and packing density of $TiO_2 films close to those of the bulk. For $ZrO_2$ films the Ar IAD increases the average refractive index decreases the negative inhomogeneity of refractive index and reverses to the positive inhomogeneity. The optical properties result from improved packing density and denser outer layer next to air The Ar-ion bombardment also induces the changes in microstructure of $ZrO_2$ films such as the preferred (111) orientation of cubic phase increase in compressive stress and reduction of surface roughness. Inhomogeneous refractive index SiOxNy films were also prepared by nitrogen IAD and variable refractive index of $SiO_xN_y$ film was applied to fabricate a rugate filter.

• Korean Journal of Optics and Photonics
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• v.9 no.3
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• pp.162-167
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• 1998

$SiO_xF_y$ optical thin films of lower refractive indices than glass substrates were fabricated by the CF$_4$ ion beam assisted deposition method and the optical, structural and chemical properties of them were investigated. Refractive index of $SiO_xF_y$ films was varied from 1.455 to 1.394 by decreasing the anode voltage or from 1.462 to 1.430 by increasing the current density of end-Hall ion source. FT-IR and XPS analyses show that as the F concentration increases, the Si-O bond at $1080m^{-1}$ shifts to higher wavenumber, the OH bonds are reduced drastically, and the fluorine atoms at the air-film interface are desorbed out by reacting with $H_2O$ in the atmosphere. $SiO_xF_y$ thin films are amorphous by the XRD analysis and have the compressive stress below 0.3 GPa. As an application of $SiO_xF_y$ thin films a two-layer antireflection coating was fabricated using a $SiO_xF_y$ film as a low refractive index layer and a Si film as an absorbing one.

• Proceedings of the Korean Vacuum Society Conference
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• 2004.08a
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• pp.188-188
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• 2004

• Korean Journal of Remote Sensing
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• v.33 no.5_1
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• pp.507-519
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• 2017

The applications of NDVI (Normalized Difference Vegetation Index) as a vegetation index has been widely used to understand vegetation biomass and physiological activities. However, NDVI is not suitable way for monitoring vegetation stress because it is less sensitive to change in physiological state than biomass. PRI (Photochemical Reflectance Index) is well developed to present physiological activities of vegetation, particularly high-light-stress condition, and it has been adopted in several satellites to be launched in the future. Thus, the understanding of PRI performance and the development of analysis method will be necessary. This study aims to interpret the characteristics of light-stress-sensitive PRI in shadow areas and to evaluate the PRI calculated by other wavelengths (i.e., 488.9 nm, 553.6 nm, 646.9 nm, and 668.4 nm) instead of 570 nm that used in original PRI. Using airborne-based hyperspectral image, we found that PRI values were increased in shadow detection due to the reduction of high light induced physiological stress. However, the qualities of both PRI and NDVI data were dramatically decreased when the shadow index (SI) exceeded the threshold (SI<25). In addition, the PRI calculated using by 553.6 nm had best correlation with original PRI. This relationship was improved by multiple regression analysis including reflectances of RED and NIR. These results will be helpful to the understanding of physiological meaning on the application of PRI.