• Korean Journal of Materials Research
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• v.27 no.12
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• pp.705-709
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• 2017

The electronic and optical characteristics of molybdenum disulphide ($MoS_2$) film significantly vary with its thickness, and thus a rapid and accurate estimation of the number of $MoS_2$ layers is critical in practical applications as well as in basic researches. Various existing methods are currently available for the thickness measurement, but each has drawbacks. Transmission electron microscopy allows actual counting of the $MoS_2$ layers, but is very complicated and requires destructive processing of the sample to the point where it will no longer be useable after characterization. Atomic force microscopy, particularly when operated in the tapping mode, is likewise time-consuming and suffers from certain anomalies caused by an improperly chosen set point, that is, free amplitude in air for the cantilever. Raman spectroscopy is a quick characterization method for identifying one to a few layers, but the laser irradiation causes structural degradation of the $MoS_2$. Optical microscopy works only when $MoS_2$ is on a silicon substrate covered with $SiO_2$ of 100~300 nm thickness. The last two optical methods are commonly limited in resolution to the micrometer range due to the diffraction limits of light. We report here a method of measuring the distribution of the number of $MoS_2$ layers using a low voltage field emission electron microscope with acceleration voltages no greater than 1 kV. We found a linear relationship between the FESEM contrast and the number of $MoS_2$ layers. This method can be used to characterize $MoS_2$ samples at nanometer-level spatial resolution, which is below the limits of other methods.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.2
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• pp.168-174
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• 2021

According to the World Agricultural Productivity Report, the current annual average growth rate of agriculture is 1.63%, which is lower than 1.73% to support the world's 10 billion people, which is growing by 2050. The demand for food, feed, and bioenergy is not growing enough to continue to meet the demand, and it is predicting a future food shortage. The purpose of this study was to create a regional irrigation control model for the purpose of reducing the production cost of crops, increasing production, and improving quality, and presenting a model that can give advice to farmers who start farming in the region. The irrigation control modeling presented in this study means to represent the change of medium weight·supply liquid·drainage amount due to changes in the root zone environment according to the passage of time and climate in a graph model. For water control modeling, we collected data on the change in the amount of the root zone environment and the weight of the badge·supply amount·drainage amount from March to June in Nonsan, Buyeo, and Yesan regions in Chungnam Province through the measuring device of the Ministry of Environment in the root region. We set up the parameters for derivation and derived an irrigation control model that can confirm the change in weight·supply liquid·drainage amount over time through the parameters.

• Korean Journal of Ichthyology
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• v.30 no.4
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• pp.185-193
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• 2018

From 2017 to 2018, the disease has been monitored at four culturing eel farms in Incheon and Gyeonggi region in Korea. As a result, diseases with gill congestion frequently occurred. This disease occurred regardless of size of eel, but the frequency and cumulative mortality were high in eels within 3 months after stocking. The infected fish showed pathological histopathological features such as intense congestion and dilation in the central venous sinus (CVS) of gill filaments and hemorrhages in liver and kidney. Hexagonal viral particles measuring about 70 nm in diameter was observed in nuclei and cytoplasm of gill vascular endothelial cells. Molecular biologic diagnosis by both PCR and genetic analysis has been revealed that the causative agent of this disease is Japanese eel endothelial cells-infecting virus (JEECV), the cause of viral endothelial cell necrosis of eel (VECNE), which is mainly reported in Japan. This study is the first report on the characteristics of JEECV and VECNE infection in domestic eel farms.

• Korean Journal of Heritage: History & Science
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• v.46 no.3
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• pp.68-77
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• 2013

This report is based on the investigation of potholes which are formed by fluvial erosion. A pothole is called so because it is a hole that looks like a coffeepot. The results of previous studies are applied to the 'Jakgwaecheon Porthole' of this study. The study is focused on the dimension and morphology of the Pothole and investigates the effects of stream sediments, river flow, geological structural lines, etc. on the formation of potholes. As a result of measuring 61 potholes in this area, we recognized that the elliptical dish-shaped cross sections are dominant and inferred that their longitudinal direction on the plain is affected by the direction of the stream flow. Also, 'Jakgwaecheon Pothole' is very characterized in terms of scale and morphology. Furthermore, it is harmonious with the beautiful landscape, humanity, and historical values and it can be suggested that it is qualified to be registered as a geoheritage structure.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.5
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• pp.301-313
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• 2021

Theoretical background for the meaning of various piezoelectric properties can be easily found in a number of textbooks and academic papers. In contrast, how they are actually measured and characterized are rarely described, though this information would be the most important especially to the researchers who just started working on the field. It follows that this report was intended to provide a practical guidance for measuring basic but essential properties of ferroelectric-based piezoelectric materials. The discussion begins with how to measurement dielectric properties such as dielectric permittivity and loss (dissipation factor), followed by piezoelectric properties such as piezoelectric constants, electromechanical coupling factor, and quality factor as well as ferroelectric features, i.e., electric field dependent polarization hysteresis. Though our discussion here is limited to the techniques that are already well-standardized, it is expected to make a seed to be developed into more challenging and creative ones.

• Journal of the Korea Society of Computer and Information
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• v.26 no.7
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• pp.65-73
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• 2021

The purpose of this study is to cornpare the differences in clinical competence, knowledge of patient safety management and confidence of patient safety management according to the clinical practice experience of nursing students, Of the 73 nursing students who experienced clinical practice and 35 nursing students who did not experience, a total of 108 students in the third grade were analyzed, In the results of this study, clinical competence(t=.88, p=.377) knowledge of patient safety management(t=-.29, p=.773), and confidence of patient safety management(t=1.11, p=.267) the difference between was not statistically significant in the two groups. In the two groups, the score of the sub-area according to each variable is the lowest. First, the sub-area of the nursing process a lowest score in clinical competence, and the second, the sub-area of measuring knowledge about concept of near miss was the Knowledge of patient safety management. The score was the lowest in, and thirdly, the sub-area of writing an incident report when an error occurred had the lowest score in confidence of patient safety management. Therefore, in order to improve the quality of clinical competence of nursing students, it is necessary to develop a strategic educational guideline to improve the clinical practice education environment, to improve patient safety management capabilities and to cultivate correct attitudes toward patient safety management.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.4
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• pp.507-520
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• 2022

The Sr isotope ratio, which is used as basic data for rock formation time, crustal and mantle evolution studies, is determined by mass spectrometer such as thermal ionization mass spectrometry (TIMS) or multi-detector inductively coupled plasma mass spectrometry (MC-ICP-MS). In this technical report, we compared how incomplete chemical separation of elements affects the determination of Sr isotope ratios. For the experiment, commercial resin, NBS987(NIST SRM987) Sr isotope standard, and rock standard samples from the Geological Survey of Japan (GSJ) such as JG1a, JB3 and JA1 were used. As a result of the comparative experiment, it was clearly observed that the measured values of ⁸⁷Sr/⁸⁶Sr change when Rb remains due to incomplete separation of the NBS987 Sr isotope standard sample as well as the rock standard samples of GSJ. This indicates that complete separation is an important factor since the calculated value deviates from the true value even though correction for isotope interference by isobar is performed when measuring the isotope ratio with MC-ICP-MS. This also suggests that, when reporting the measurement result of Sr isotope ratio using MC-ICP-MS, the measurement strength of ⁸⁵Rb should be reported together with the measurement strength of all isotopes of Sr so that isotope interference by isobar can be judged.

• The Korea Journal of Herbology
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• v.33 no.2
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• pp.69-77
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• 2018

Objectives : Daesiho-tang (DSHT) has been widely used in the treatment of cerebral infarct in traditional medicine. However, there was not report on the anti-obesity-related diseases efficacy of DSHT. In this study, we investigated the effects for the new formulation of DSHT, on the adipocyte differentiation cycle in 3T3-L1 cells. Methods : 3T3-L1 cells were treated with DSHT (50, 100, $200{\mu}g/m{\ell}$) during differentiation for 6 days. Also, the inhibitory effect of DSHT against 3T3-L1 adipogenesis was evaluated in various stage of adipogenesis such as early (0-2day), intermediate (2-4day), and terminal stage (4-6day). The accumulation of lipid droplets was determined by Oil Red O staining. and, the expressions of genes related to adipogenesis were measured by RT-PCR and Western blot analyses. Results : DSHT showed inhibitory activity on adipocyte differentiation at 3T3-L1 preadipocytes without affect cell toxicity as assessed by measuring fat accumulation and adipogenesis. In addition, DSHT significantly reduced the expression levels of several adipocyte marker genes including proliferator activated $receptor-{\gamma}$ ($PPAR-{\gamma}$) and CCAAT/ enhancer-binding $protein-{\alpha}$ ($C/EBP-{\alpha}$). Also, the anti-adipogenic effect of DSHT was strongly limited in the intermediate (2-4 day), terminal stage (4-6 day) of 3T3-L1 adipogenesis. In addition, the DSHT treatment down- regulated mRNA expression levels of $PPAR-{\gamma}$,, $C/EBP-{\alpha}$ in mature 3T3-L1 adipocytes. Conclusions : These results suggest that, the ability of DSHT has inhibited overall adipogenesis and lipid accumulation in the 3T3-L1 cells. The new formulation of DSHT may be a promising medicine for the treatment of obesity and related metabolic disorders.

• The Journal of the Society of Stroke on Korean Medicine
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• v.19 no.1
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• pp.21-30
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• 2018

■ Objectives This case study is to report the two cases of Gami-Guibitang on cognitive impairment after stroke with improved recall memory. ■ Methods We used Korean medicine treatments including Gami-guibitang, acupuncture and moxibustion to treat patients who had cognitive impairment after stroke for at least two months. We observed the changes of symptoms by measuring Korean version of Mini-mental status examination (MMSE-K), Clinical Dementia Rating (CDR) and Global Detration Scale (GDS). ■ Results After treatment, the patient's symptoms were improved including MMSE-K, CDR and GDS. Improvement appeared to be prominent in recall memory. The general condition were also improved after treatment. ■ Conclusion This clinical case study suggests that Korean medicine including Gami-guibitang could be used to treat patients who had cognitive impairment after stroke especially suffering from degraded recall memory.

• Korean Journal of Culture and Social Issue
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• v.29 no.4
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• pp.569-593
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• 2023

The purpose of this study was to investigate the mediating effects of rejection sensitivity in pathological narcissism and dating violence, and to verify whether there is a gender difference in each variable, further examining the gender difference in the mediating pathways. The participants of this study were 381 men and women in 20s living across the country, and online self-report surveys was conducted regarding their experiences of pathological narcissism, rejection sensitivity, and four types of dating violence. As a result of verifying gender differences, it was found that women had a higher vulnerability to narcissism, rejection sensitivity and committed more psychological violence, sexual violence, and controlling behavior than men. As a result of the mediation analysis, it was found that rejection sensitivity partial mediated the effect of pathological narcissism on psychological violence and control behavior, but it showed a complete mediation effect on sexual violence. And there was no mediating effect of rejection sensitivity between pathological narcissism and physical violence. As a result of measuring the moderating effect of gender in this mediating pathways, the moderated mediating effect of gender was verified in the effect of naricissistic grandiosity and narcissistic vulnerability on control behavior through rejection sensitivity. These results show that pathological narcissism promotes psychological and sexual violence in both men and women, and rejection sensitivity acts as a mediator in this process. In addition, the effect of pathological narcissism on the control behaviors through rejection sensitivity was significantly higher in women than in men, indicating that there are gender differences in the mediated pathways. Finally, the implications and limitations of this study and suggestions for follow-up studies were discussed.