• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.21 no.4
• /
• pp.167-189
• /
• 2022

In the case of SAE autonomous driving levels 2 and 3, since complete autonomous driving is impossible, the take-over process is essential, and take-over time(TOT) is the most important factor in determining the safety of the autonomous driving system. Accordingly, research on TOT is being actively conducted, but each research is independently conducted and general conclusions that integrate various research results are required. Therefore, in this study, the factors affecting TOT were analyzed using meta-analysis, which integrates the results of individual studies and presents an integrated opinion. As a result of meta-analysis, a total of 10 influencing factors were selected, and most of them were related to the non-driving related task(NDRT) type. In addition, implications for the future research direction of take-over and NDRT were presented.

• Journal of Korean Society for Atmospheric Environment
• /
• v.31 no.5
• /
• pp.449-460
• /
• 2015

Carbonaceous aerosol is generally classified into OC (organic carbon) and EC (elemental carbon) by thermal optical analysis. Both NIOSH (National institute of occupational safety and health) with high temperature (HighT) and IMPROVE-A (Interagency monitoring of protected visual environments) with low temperature (LowT) protocols are widely used. In this study, both protocols were applied for ambient $PM_{2.5}$ samples (Daejeon, Korea) in order to underpin differences in OC and EC measurements. An excellent agreement between NIOSH and IMPROVE-A protocol was observed for TC (total carbon). However, significant differences between OC and EC appeared and the differences were larger for EC than OC. The main differences between two protocols are temperature profile and charring correction method. For the same charring correction method, HighT_OC was 10% higher than LowT_ OC, while HighT_EC was 15% and 33% lower than LowT_EC for TOT (thermal-optical transmittance) and TOR (thermal-optical reflectance), respectively. This difference may be caused by the temperature of OC4 in He step and possibly difference in POC (pryorilized OC) formation. For the same temperature profile, OC by TOT was about 26% higher than that by TOR. In contrast, EC by TOT was about 50% lower than that by TOR. POC was also dependent on both temperature profile and the charring correction method, showing much distinctive differences for the charring correction method (i.e., POC by TOT to POC by TOR ratio is about 2). This difference might be caused by different characteristics between transmittance and reflectance for monitoring POC formation within filters. Results from this study showed that OC and EC depends on applied analysis protocol as shown other studies. Because of the nature of the thermal optical analysis, it may not be possible to have an absolute standard analysis protocol that is applicable for any ambient $PM_{2.5}$. Nevertheless, in order to provide consistent measurement results for scientists and policy makers, future studies should focus on developing a harmonized standard analysis protocol that is suitable for a specific air domain and minimizes variations in OC and EC measurement results. In addition, future elaborate studies are required to find and understand the causes of the differences.

• Economic and Environmental Geology
• /
• v.55 no.4
• /
• pp.389-398
• /
• 2022

Many studies have been conducted to accurately predict the correlations between As and heavy metals content in contaminated soil and cultivated crops; however, due to the low correlation between the two, few clear results were obtained to date. This study aimed to create statistical models that predict the As content transferred from soil to polished rice, considering the physicochemical properties of the soil, as well as the total content and the single-extracted content of As in the soil. Predictive models were derived through regression analysis while sequentially classifying soil samples according to pH, soluble As content by single extraction, and organic matter content of the soil. The correlation coefficients between the As content in 80 polished rice and total As content and Mehlich soluble As content in the soil were low, 0.533 and 0.493, respectively. However, the models derived after sequential classification of the soil by pH, a ratio of total As content to Mehlich soluble As content, and organic matter content greatly increased the predictive power; ① 0.963 for 13 soils with a pH higher than 6.5, ② 0.849 for 15 soils with pH lower than 6.5 and a high ratio of As_Tot/As_Mehlich, ③ 0.935 for 30 soils with pH lower than 6.5, a high ratio of As_Tot/As_Mehlich, and organic matter content lower than 8.5%. The suggested prediction model of As transfer from soil to polished rice derived by soil classification may serve as a statistically significant methodology in establishing a rice cultivation standard for arsenic-contaminated soil.

• Proceedings of the Korean Aquaculture Society Conference
• /
• 2006.05a
• /
• pp.501-503
• /
• 2006

• PNF and Movement
• /
• v.8 no.3
• /
• pp.9-16
• /
• 2010

Purpose : The purpose of this study was to investigate effects of kinesio taping of thigh muscle on isokinetic muscular function during closed kinetic chain exercise of lower extremity. Methods : Twenty healthy males were participated in this study. The isokinetic muscular function of closed kinetic chain were measured for peak torque, peak torque % body weight, average power, max rep tot work before and after application of kinesio taping on thigh muscles. Results : At $60^{\circ}/s$ peak force and peak force % body weight were significant increased in both extension(p<0.01) and flexion(p<0.001) after applying kinesio taping. At $180^{\circ}/s$ average power was significant increased in both extension and flexion after applying taping(p<0.001). At $240^{\circ}/s$ max rep tot work was significant increased in both extension(p<0.001) and flexion(p<0.05). Conclusion : This study suggests that application of kinesio taping on thigh muscle was more effective to improve isokinetic muscular function in closed kinetic chain exercise of lower extremity.

• Journal of Oriental Medical Thermology
• /
• v.4 no.1
• /
• pp.1-14
• /
• 2005

The purpose of this study is to identify the clinical effects of Jujadanggui-hwan in the treatment of dysmenorrhea with cold hypersensitivity. Jujadanggui-hwan mentioned in Dongeuibogam has an effect on leucorrhea and cold hypersensitivity of hands and feet, lower abdomen and lumbus. Jujadanggui-hwan were prescribed to 24 dysmenorrhea patients with cold hypersensitivity of hands and feet or with leucorrhea three times a day for 13 weeks. After the treatment, numerical index for the pain was obviously reduced 'tot' point 2.12. It means that pain index as the patient can't do everyday occurrences reduce to 3 grad enough to do ordinary experience. So this study shows that Jujadanggui-hwan has remarkable effects on dysmenorrhea with cold hypersensitivity.

• Computers and Concrete
• /
• v.8 no.3
• /
• pp.343-355
• /
• 2011

This paper presented the model to predict the chloride diffusion coefficient in tension zone of plain concrete under flexural cyclic load. The fictitious crack based analytical model was used together with the stress degradation law in cracked zone to predict crack growth of plain concrete beams under flexural cyclic load. Then, under cyclic load, the chloride diffusion, in the steady state and one dimensional regime, through the tension zone of the plain concrete beam, in which microcracks were formed by a large number of cycles, was simulated with assumptions of continuously straight crack and uniform-size crack. The numerical analysis in terms of the chloride diffusion coefficient, $D_{tot}$, normalized $D_{tot}$, crack width and crack length was issued as a function of the load cycle, N, and load level, SR. The nonlinear model as regarding with the chloride diffusion coefficient in tension zone and the load level was proposed. According to this model, the chloride diffusion increases with increasing load level. The predictions using model fit well with experimental data when we adopted suitable crack density and tortuosity parameter.

• Journal of Astronomy and Space Sciences
• /
• v.14 no.1
• /
• pp.80-86
• /
• 1997

High energy particles in the earth's radiation belts cause transient and long term effects on electronic materials, devices, and integrated circuits on board the satellites. Hence, it is very important to have the information on the space radiation environment and the damage on the electronics caused by the se high energy particles. One of the radiation monitor devices frequently used in space is RADFET, a specially designed MOSFET with a thick gate oxide region. The present study focuses on the calibration of RADFET TOT500 using the $Co^{60}{\gamma}-ray$ source. The result shows that the response of RADFET is very sensitive to the change of temperature. The peculiar behavior observed in the TDE (Total Dose Experiment) on board the KITSAT-1 is identified as the thermal effect due to the change in the eclipse rate of the satellite.

• Publications of The Korean Astronomical Society
• /
• v.30 no.2
• /
• pp.457-459
• /
• 2015

Observations show that the accretion flows in low-luminosity active galactic nuclei (LLAGNs) probably have a two-component structure with an inner hot, optically thin, advection dominated accretion flow (ADAF) and an outer truncated cool, optically thick accretion disk. As shown by Taam et al. (2012), within the framework of the disk evaporation model, the truncation radius as a function of mass accretion rate is strongly affected by including the magnetic field. We define the parameter ${\beta}$ as $p_m=B^2/8{\pi}=(1-{\beta})p_{tot}$, (where $p_{tot}=p_{gas}+p_m$, $p_{gas}$ is gas pressure and $p_m$ is magnetic pressure) to describe the strength of the magnetic field in accretion flows. It is found that an increase of the magnetic field (decreasing the value of ${\beta}$) results in a smaller truncation radius for the accretion disk. We calculate the emergent spectrum of an inner ADAF + an outer truncated accretion disk around a supermassive black hole by considering the effects of the magnetic field on the truncation radius of the accretion disk. By comparing with observations, we found that a weaker magnetic field (corresponding to a bigger value of ${\beta}$) is required to match the observed correlation between $L_{2-10keV}/L_{Edd}$ and the bolometric correction $k_{2-10keV}$, which is consistent with the physics of the accretion flow with a low mass accretion rate around a black hole.

• Journal of the Korean Physical Society
• /
• v.73 no.9
• /
• pp.1370-1376
• /
• 2018

The electronic structures, magnetic properties and half-metallicity in $Zr_2RuZ$ (Z = Ga, In, Tl, Ge, Sn, and Pb) alloys with $AlCu_2Mn-$ and $CuHg_2Ti$-type structures were investigated using first-principles density functional theory (DFT) calculations. The calculations showed that $Zr_2RuIn$, $Zr_2RuTl$, $Zr_2RuSn$, and $Zr_2RuPb$ compounds with $CuHg_2Ti$-type structures were half-metallic ferromagnets with half-metallic band gaps of 0.18, 0.24, 0.22, and 0.27 eV, respectively. The half-metallicity originated from d-d and covalent hybridizations between the transition metals Zr and Ru. The total magnetic moments of the $Zr_2RuZ$ (Z = In, Tl, Sn, and Pb) compounds with $CuHg_2Ti$-type structures were integer values of $1{\mu}B$ and $2{\mu}B$, which is in agreement with Slater-Pauling rule ($M_{tot}=Z_{tot}-18$). Among these compounds, $Zr_2RuIn$ and $Zr_2RuTl$ were half-metals over relatively wide regions of the lattice constants, indicating that these two new Heusler alloys are ideal candidates for use in spintronic devices.