• Journal of the Korean earth science society
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• v.32 no.6
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• pp.674-686
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• 2011

Choosing a seismic source and geophone type including a coupling method can be the most important factor in shallow seismic surveys. We studied the characteristics of seismic signals by analyzing 6 different seismic data sets that collected from several sources and geophone conditions. Geophones attached to weight plate (1.8 kg) can be easily and economically installed on the paved road where geophones with spikes would cause the coupling problem. In addition, experiments in this study revealed that a small handy hammer can be used as a seismic source by striking the paved road to generate the seismic signals within 200 ms two-way travel time. Attaching weight plates to geophones may change the geophone response curve which generally depends on the geophone mass, but the change seems not to give significant differences in the first arrival of refracted wave and in the pattern of reflection events. Consequently, using weight plates on paved roads can be an efficient and cost-saving method in the near-surface high-resolution seismic surveys.

• The Journal of the Korea Contents Association
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• v.11 no.9
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• pp.437-442
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• 2011

The purpose of this study is an measurement of the skin dose of a patient by using the OSLD(optically stimulated luminescent dosimeter) under several irradiation conditions of the X-ray beam for diagnostic radiography. The measurements of skin dose were performed for head, chest, and pelvis. And test of reproducibility was carried out at the chest. As a result, we obtained the skin dose at forehead of head to be 1.30 mSv. The skin doses at xiphoid process, breast and apex of the lung of the chest were acquired 0.92, 0.52 and 0.70 mSv, respectively. And we obtained the skin doses at the left pelvis and the right pelvis to be 2.78 and 3.08 mSv, respectively. As for reproducibility, a coefficient of variation was 0.033. The skin doses were exhibited the values corresponding from 1/100 to 1/17 of the dose limit of the public(50 mSv) at the deterministic effect. In order to make accurate measurements of the skin doses for each tube voltage, the measured values have to multiply by the displayed values of reader by a correction factor. The energy response of the OSLD with the tube voltage will be studied in the near future.

• Journal of the Korean Society of Radiology
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• v.8 no.7
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• pp.449-454
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• 2014

The purpose of this study is(was) to investigate the shielding ratio of 1 mmPb and the off axis ratio outside the field edge at depth of 1 cm from a phantom surface for 6 MV photon beam. A dose of 180 cGy was delivered to a depth of 10 cm for a $10{\times}10cm^2$ and $15{\times}15cm^2$ field in the SAD technique. The off axis ratio was calculated by measuring the dose of optically stimulated luminescent nanoDot dosimeters(OSLnDs) positioned at 2, 4 and 6 cm from the field edge, and the center axis of field. And the shielding ratio of 1 mmPb was calculated by measuring the dose of OSLnDs positioned at 2, 4 and 6 cm from the field edge.. As a result, for a $10{\times}10cm^2$ and $15{\times}15cm^2$ field, the off axis ratios were acquired 0.008-0.023 and 0.011-0.028, respectively. Also the shielding ratios of 1 mmPb were acquired 0.868-0.888 and 0.807-0.842, respectively. These results provide data to protect organs at risk outside the radiation treatment field.

• International Journal of Oral Biology
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• v.33 no.4
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• pp.163-177
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• 2008

Periodontal disease, a form of chronic inflammatory bacterial infectious disease, is known to be a risk factor for cardiovascular disease (CVD). Porphyromonas gingivalis has been implicated in periodontal disease and widely studied for its role in the pathogenesis of CVD. A previous study demonstrating that periodontopathic P. gingivalis is involved in CVD showed that invasion of endothelial cells by the bacterium is accompanied by an increase in cytokine production, which may result in vascular atherosclerotic changes. The present study was performed in order to further elucidate the role of P. gingivalis in the process of atherosclerosis and CVD. For this purpose, invasion of human aortic smooth muscle cells (HASMC) by P. gingivalis 381 and its isogenic mutants of KDP150 ($fimA^-$), CW120 ($ppk^-$) and KS7 ($relA^-$) was assessed using a metronidazole protection assay. Wild type P. gingivalis invaded HASMCs with an efficiency of 0.12%. In contrast, KDP150 failed to demonstrate any invasive ability. CW120 and KS7 showed relatively higher invasion efficiencies, but results for these variants were still negligible when compared to the wild type invasiveness. These results suggest that fimbriae are required for invasion and that energy metabolism in association with regulatory genes involved in stress and stringent response may also be important for this process. ELISA assays revealed that the invasive P. gingivalis 381 increased production of the proinflammatory cytokine interleukin (IL)-$1{\beta}$ and the chemotactic cytokines (chemokine) IL (interleukin)-8 and monocyte chemotactic (MCP) protein-1 during the 30-90 min incubation periods (P<0.05). Expression of RANTES (regulation upon activation, normal T cell expressed and secreted) and Toll-like receptor (TLR)-4, a pattern recognition receptor (PRR), was increased in HASMCs infected with P. gingivalis 381 by RT-PCR analysis. P. gingivalis infection did not alter interferon-$\gamma$-inducible protein-10 expression in HASMCs. HASMC nonspecific necrosis and apoptotic cell death were measured by lactate dehydrogenase (LDH) and caspase activity assays, respectively. LDH release from HASMCs and HAMC caspase activity were significantly higher after a 90 min incubation with P. gingivalis 381. Taken together, P. gingivalis invasion of HASMCs induces inflammatory cytokine production, apoptotic cell death, and expression of TLR-4, a PRR which may react with the bacterial molecules and induce the expression of the chemokines IL-8, MCP-1 and RANTES. Overall, these results suggest that invasive P. gingivalis may participate in the pathogenesis of atherosclerosis, leading to CVD.

• Journal of Microbiology and Biotechnology
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• v.20 no.11
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• pp.1563-1570
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• 2010

To construct a highly sensitive detection system for endocrine disruptors (EDs), we have compared the activity of promoters with the n-alkane-inducible cytochrome P450 gene (ALK1), isocitrate lyase gene (ICL1), ribosomal protein S7 gene (RPS7), and the translation elongation factor-1${\alpha}$ gene (TEF1) for the heterologous gene in Yarrowia lipolytica. The promoters were introduced into the upstream of the lacZ or hERa reporter genes, respectively, and the activity was evaluated by ${\beta}$-galactosidase assay for lacZ and Western blot analysis for hER${\alpha}$. The expression analysis revealed that the ALK1 and ICL1 promoters were induced by n-decane and by EtOH, respectively. The constitutive promoter of RPS7 and TEF1 showed mostly a high level of expression in the presence of glucose and glycerol, respectively. In particular, the TEF1 promoter showed the highest ${\beta}$-galactosidase activity and a significant signal by Western blotting with the anti-estrogen receptor, compared with the other promoters. Moreover, the detection system was constructed with promoters linked to the upstream of the expression vector for the hER${\alpha}$ gene transformed into the Y. lipolytica with a chromosome-integrated lacZ reporter gene under the control of estrogen response elements (EREs). It was indicated that a combination of pTEF1p-hER${\alpha}$ and CXAU1-2XERE was the most effective system for the $E_2$-dependent induction of the ${\beta}$-galactosidase activity. This system showed the highest ${\beta}$-galactosidase activity at $10^{-6}\;M\;E_2$, and the activity could be detected at even the concentration of $10^{-10}\;M\;E_2$. As a result, we have constructed a strongly sensitive detection system with Y. lipolitica to evaluate recognized/suspected ED chemicals, such as natural/synthetic hormones, pesticides, and commercial chemicals. The results demonstrate the utility, sensitivity, and reproducibility of the system for identifying and characterizing environmental estrogens.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.65-65
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• 2012

Copper zinc tin sulfide ($Cu_2ZnSnS_4$, CZTS) is a very promising material as a low cost absorber alternative to other chalcopyrite-type semiconductors based on Ga or In because of the abundant and economical elements. In addition, CZTS has a band-gap energy of 1.4~1.5eV and large absorption coefficient over ${\sim}10^4cm^{-1}$, which is similar to those of $Cu(In,Ga)Se_2$(CIGS) regarded as one of the most successful absorber materials for high efficient solar cell. Most previous works on the fabrication of CZTS thin films were based on the vacuum deposition such as thermal evaporation and RF magnetron sputtering. Although the vacuum deposition has been widely adopted, it is quite expensive and complicated. In this regard, the solution processes such as sol-gel method, nanocrystal dispersion and hybrid slurry method have been developed for easy and cost-effective fabrication of CZTS film. Among these methods, the hybrid slurry method is favorable to make high crystalline and dense absorber layer. However, this method has the demerit using the toxic and explosive hydrazine solvent, which has severe limitation for common use. With these considerations, it is highly desirable to develop a robust, easily scalable and relatively safe solution-based process for the fabrication of a high quality CZTS absorber layer. Here, we demonstrate the fabrication of a high quality CZTS absorber layer with a thickness of 1.5~2.0 ${\mu}m$ and micrometer-scaled grains using two different non-vacuum approaches. The first solution-processing approach includes air-stable non-toxic solvent-based inks in which the commercially available precursor nanoparticles are dispersed in ethanol. Our readily achievable air-stable precursor ink, without the involvement of complex particle synthesis, high toxic solvents, or organic additives, facilitates a convenient method to fabricate a high quality CZTS absorber layer with uniform surface composition and across the film depth when annealed at $530^{\circ}C$. The conversion efficiency and fill factor for the non-toxic ink based solar cells are 5.14% and 52.8%, respectively. The other method is based on the nanocrystal dispersions that are a key ingredient in the deposition of thermally annealed absorber layers. We report a facile synthetic method to produce phase-pure CZTS nanocrystals capped with less toxic and more easily removable ligands. The resulting CZTS nanoparticle dispersion enables us to fabricate uniform, crack-free absorber layer onto Mo-coated soda-lime glass at $500^{\circ}C$, which exhibits a robust and reproducible photovoltaic response. Our simple and less-toxic approach for the fabrication of CZTS layer, reported here, will be the first step in realizing the low-cost solution-processed CZTS solar cell with high efficiency.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.3
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• pp.212-218
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• 2020

When Radiofrequency energy is applied to the human body, the vibration width is very short. Therefore, the electrolyte burn generated when using the direct current does not occur. Ion molecules, polarized molecules, etc., vibrate more than 40,000 times per second, converting them into frictional heat to generate deep heat. The blood flow of capillaries increases 4-5 times more than at rest, increasing the supply of oxygen, nutrients, antibodies, and white blood cells. In addition, the electrochemical reaction does not occur because the vibration width and the pulsation period are very short. It is a physical factor treatment method that does not stimulate the sensory nerves and motor nerves. In this study, an isotonic exercise is performed in a young normal adult using a Radiofrequency pain treatment device. The purpose of this study is to integrate rehabilitation therapy by measuring electromyography data during isotonic exercise and confirming the effect on changes in motor neuron response. The EMG data generated when isotonic exercise of the forearm biceps muscle and the EMG data measured after the use of a Radiofrequency pain treatment device after exercise were RMS, respectively, and verified through t-test. It was confirmed that there was a significant difference in both men and women because the t-value was smaller than the significance level p (<.05).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1756-1762
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• 2011

The aim of the present investigation was to investigate the relationship of repeated racehorse simulator exercise on plasma ghrelin and hormons in fasted jockeys. The fasted jockeys and apprentice jockeys performed $1^{st}$ short distance 1000m, $2^{nd}$ middle distance 1700m and $3^{rd}$ long distance 2300m racehorse simulator exercises, and venous blood samples were obtained before, immediately after. In addition to ghrelin concentration, leptin, insulin, insulin-like growth factor-1 (IGF-1), and cortisol values were measured. Pearson correlation coefficients revealed plasma ghrelin and insulin concentration in apprentice jockeys r=.55 after the $3^{rd}$ exercise. There were relationships between significant relationships (p<.05) between plasma ghrelin and leption concentration in jockeys r=.73, and between plasma ghrelin and cortisol concentration in apprentice jockeys r=.64 before exercise. There was no difference in the ghrelin, leptin, insulin and IGF-1 concentration responses to the consecutive exercise. The IGF-1 and cortisol level showed significant (p<.05)difference between groups. In conclusion, these results suggest that negative energy balance induced by of repeated racehorse simulator exercise elicits a metabolic response with positive relationship in plasma ghrelin and insulin in apprentice jockeys after the $3^{rd}$ exercise.

• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.569-577
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• 2023

This study selected seven carbon-neutral villages, considering the characteristics of each region, including all five administrative districts of Changwon City, and proposed activation plans based on business evaluations through surveys of local residents and FGIs with leaders. The analysis showed that carbon-neutral education was the most important factor for activating carbon-neutral villages, with a response rate of 91.9% for 17 multiple-choice questions, followed by legal (ordinance) arrangements at 79.3% and village organization building at 74.1%. Based on this, the following activation plans through the participation of residents who are involved in the project of creating a carbon-neutral village in Changwon City were proposed. First, the characteristics of each carbon-neutral village model were classified into a resource circulation-based model, an environmental creation-based model, an environmental education and experience event-based model, and an energy efficiency-based model. Second, it is necessary to create and present carbon-neutral village growth stage guidelines for the growth of carbon-neutral villages. Third, manuals and teaching materials related to carbon neutrality, such as theories, issues, and practices, need to be produced and distributed for leaders and activists to easily apply and access for self-government operation of the village. Finally, if a carbon-neutral support center that is legally installable in Changwon City is established, it is expected that the lives of local residents will become more sustainable for carbon-neutral living in preparation for climate crises.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.1
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• pp.33-46
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• 2010

We investigated and estimated at the characteristics of decomposition and by-products of N-Nitrosodimethylamine (NDMA) using a design of experiment (DOE) based on the Box-Behken design in an UV process, and also the main factors (variables) with UV intensity($X_2$) (range: $1.5{\sim}4.5\;mW/cm^2$), NDMA concentration ($X_2$) (range: 100~300 uM) and pH ($X_2$) (rang: 3~9) which consisted of 3 levels in each factor and 4 responses ($Y_1$ (% of NDMA removal), $Y_2$ (dimethylamine (DMA) reformation (uM)), $Y_3$ (dimethylformamide (DMF) reformation (uM), $Y_4$ ($NO_2$-N reformation (uM)) were set up to estimate the prediction model and the optimization conditions. The results of prediction model and optimization point using the canonical analysis in order to obtain the optimal operation conditions were $Y_1$ [% of NDMA removal] = $117+21X_1-0.3X_2-17.2X_3+{2.43X_1}^2+{0.001X_2}^2+{3.2X_3}^2-0.08X_1X_2-1.6X_1X_3-0.05X_2X_3$ ($R^2$= 96%, Adjusted $R^2$ = 88%) and 99.3% ($X_1:\;4.5\;mW/cm^2$, $X_2:\;190\;uM$, $X_3:\;3.2$), $Y_2$ [DMA conc] = $-101+18.5X_1+0.4X_2+21X_3-{3.3X_1}^2-{0.01X_2}^2-{1.5X_3}^2-0.01X_1X_2+0.07X_1X_3-0.01X_2X_3$ ($R^2$= 99.4%, 수정 $R^2$ = 95.7%) and 35.2 uM ($X_1$: 3 $mW/cm^2$, $X_2$: 220 uM, $X_3$: 6.3), $Y_3$ [DMF conc] = $-6.2+0.2X_1+0.02X_2+2X_3-0.26X_1^2-0.01X_2^2-0.2X_3^2-0.004X_1X_2+0.1X_1X_3-0.02X_2X_3$ ($R^2$= 98%, Adjusted $R^2$ = 94.4%) and 3.7 uM ($X_1:\;4.5\;$mW/cm^2$, $X_2:\;290\;uM$, $X_3:\;6.2$) and $Y_4$ [$NO_2$-N conc] = $-25+12.2X_1+0.15X_2+7.8X_3+{1.1X_1}^2+{0.001X_2}^2-{0.34X_3}^2+0.01X_1X_2+0.08X_1X_3-3.4X_2X_3$ ($R^2$= 98.5%, Adjusted $R^2$ = 95.7%) and 74.5 uM ($X_1:\;4.5\;mW/cm^2$, $X_2:\;220\;uM$, $X_3:\;3.1$). This study has demonstrated that the response surface methodology and the Box-Behnken statistical experiment design can provide statistically reliable results for decomposition and by-products of NDMA by the UV photolysis and also for determination of optimum conditions. Predictions obtained from the response functions were in good agreement with the experimental results indicating the reliability of the methodology used.