• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.47 no.1
• /
• pp.1-7
• /
• 2021

With increasing interest in the effectiveness and safety of sunscreen worldwide, research on the development of new inorganic sunscreen is also gaining momentum. In the present study, non-nano sized needle type zinc oxide, which can meet the regulation of nano-material as a recent problem, has been synthesized and surface-modified with cetyl alcohol to obtain needle type zinc oxide powder. Here, we also investigated their physical properties and evaluated their potential application as sunscreens. As a result of the experiment, the sunscreen with needle type zinc oxide powder, which was non-nano, showed similar UV-protection properties and transparency compare to that of 40nm size zinc oxide. It was further confirmed that the UV blocking effect was significantly increased when the needle type zinc oxide dispersion was applied to the sunscreen. Therefore, although the needle type zinc oxide is non-nano (200 nm) material, it has the potential to be applied to the product as an excellent transparency (improvement of whiteness), UV protection efficacy and smooth texture.

• Journal of Digital Convergence
• /
• v.19 no.3
• /
• pp.187-194
• /
• 2021

OSINT(Open Source Intelligence), rapidly increasing on the surface web in various forms, can also be used for criminal investigations by using profiling. This technique has become quite common in foreign investigative agencies such as the United States. On the other hand, in Korea, it is not used a lot, and there is a large deviation in the quantity and quality of information acquired according to the experience and knowledge level of investigator. Unlike Bazzell's most well-known model, we designed a Korean-style OSINT-based profiling technique that considers the Korean web environment and provides timeline information, focusing on the improved workflow. The database schema to improve the efficiency of profiling is also presented. Using this, we can obtain search results that guarantee a certain level of quantity and quality. And it can also be used as a standard training course. To increase the effectiveness and efficiency of criminal investigations using this technique, it is necessary to strengthen the legal basis and to introduce automation technologies.

• Journal of the Korea Convergence Society
• /
• v.13 no.3
• /
• pp.281-289
• /
• 2022

Plasma ozone is utilized in a variety of applications in the field of sterilization due to its high sterilization performance. Dielectric materials used in DBD(dielectric barrier discharges) are mainly polymer, quartz and ceramics. These dielectric layers have the advantage of limiting the amount of supplied electron charge and allowing plasma to occur evenly on the surface of dielectric. Actually, the target or environment for sterilization is often a complex structure, so research and academic study are needed by utilizing the concept of space sterilization. In this study, the device is applied to generate DBD plasma at atmospheric pressure for disinfection due to the effectiveness in producing radicals and ozone. The generator of plasma ozone is a basic structure of dielectric barrier discharge by placing ceramic tube dielectrics and stainless steel electrical conductors at regular intervals. Various applications can be developed based on the proposed design method. Plasma ozone generation for space sterilization device is recognized as an excellent sterilization device. Through the design and verification of the device, we intend to establish an optimal design of the spatial sterilization device and provide the basis data for sterilization applications.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.29 no.2
• /
• pp.101-115
• /
• 2024

The ocean heatwave is emerging as a major issue due to global warming, posing a direct threat to marine ecosystems and humanity through decreased food resources and reduced carbon absorption capacity of the oceans. Consequently, the prediction of ocean heatwaves in the vicinity of the Korean Peninsula is becoming increasingly important for marine environmental monitoring and management. In this study, an LSTM model was developed to improve the underestimated prediction of ocean heatwaves caused by the coarse vertical grid system of the Korean Peninsula Ocean Prediction System. Based on the results of ocean heatwave predictions for the Korean Peninsula conducted in 2023, as well as those generated by the LSTM model, the performance of heatwave predictions in the East Sea, Yellow Sea, and South Sea areas surrounding the Korean Peninsula was evaluated. The LSTM model developed in this study significantly improved the prediction performance of sea surface temperatures during periods of temperature increase in all three regions. However, its effectiveness in improving prediction performance during periods of temperature decrease or before temperature rise initiation was limited. This demonstrates the potential of the LSTM model to address the underestimated prediction of ocean heatwaves caused by the coarse vertical grid system during periods of enhanced stratification. It is anticipated that the utility of data-driven artificial intelligence models will expand in the future to improve the prediction performance of dynamical models or even replace them.

• Nuclear Engineering and Technology
• /
• v.55 no.11
• /
• pp.3940-3955
• /
• 2023

A new method of numerical simulating prediction and decontamination effect evaluation for abrasive jet decontamination to radioactively contaminated metal is proposed. Based on the Computational Fluid Dynamics and Discrete Element Model (CFD-DEM) coupled simulation model, the motion patterns and distribution of abrasives can be predicted, and the decontamination effect can be evaluated by image processing and recognition technology. The impact of three key parameters (impact distance, inlet pressure, abrasive mass flow rate) on the decontamination effect is revealed. Moreover, here are experiments of reliability verification to decontamination effect and numerical simulation methods that has been conducted. The results show that: ⁶⁰Co and other homogeneous solid solution radioactive pollutants can be removed by abrasive jet, and the average removal rate of Co exceeds 80%. It is reliable for the proposed numerical simulation and evaluation method because of the well goodness of fit between predicted value and actual values: The predicted values and actual values of the abrasive distribution diameter are Ф57 and Ф55; the total coverage rate is 26.42% and 23.50%; the average impact velocity is 81.73 m/s and 78.00 m/s. Further analysis shows that the impact distance has a significant impact on the distribution of abrasive particles on the target surface, the coverage rate of the core area increases at first, and then decreases with the increase of the impact distance of the nozzle, which reach a maximum of 14.44% at 300 mm. It is recommended to set the impact distance around 300 mm, because at this time the core area coverage of the abrasive is the largest and the impact velocity is stable at the highest speed of 81.94 m/s. The impact of the nozzle inlet pressure on the decontamination effect mainly affects the impact kinetic energy of the abrasive and has little impact on the distribution. The greater the inlet pressure, the greater the impact kinetic energy, and the stronger the decontamination ability of the abrasive. But in return, the energy consumption is higher, too. For the decontamination of radioactively contaminated metals, it is recommended to set the inlet pressure of the nozzle at around 0.6 MPa. Because most of the Co elements can be removed under this pressure. Increasing the mass and flow of abrasives appropriately can enhance the decontamination effectiveness. The total mass of abrasives per unit decontamination area is suggested to be 50 g because the core area coverage rate of the abrasive is relatively large under this condition; and the nozzle wear extent is acceptable.

• Imaging Science in Dentistry
• /
• v.49 no.4
• /
• pp.295-299
• /
• 2019

Purpose: This clinical pilot study was performed to determine the effectiveness of dual-energy cone-beam computed tomography (DE-CBCT) in measuring bone mineral density (BMD). Materials and Methods: The BMD values obtained using DE-CBCT were compared to those obtained using calibrated multislice computed tomography (MSCT). After BMD calibration with specially designed phantoms, both DE-CBCT and MSCT scanning were performed in 15 adult dental patients. Three-dimensional (3D) Digital Imaging and Communications in Medicine data were imported into a dental software program, and the defined regions of interest (ROIs) on the 3-dimensional surface-rendered images were identified. The automatically-measured BMD values of the ROIs (g/㎤), the differences in the measured BMD values of the matched ROIs obtained by DE-CBCT and MSCT 3D images, and the correlation between the BMD values obtained by the 2 devices were statistically analyzed. Results: The mean BMD values of the ROIs for the 15 patients as assessed using DE-CBCT and MSCT were 1.09±0.07 g/㎤ and 1.13±0.08 g/㎤, respectively. The mean of the differences between the BMD values of the matched ROIs as assessed using DE-CBCT and calibrated MSCT images was 0.04±0.02 g/㎤. The Pearson correlation coefficient between the BMD values of DE-CBCT and MSCT images was 0.982 (r=0.982, P<0.001). Conclusion: The newly developed DE-CBCT technique could be used to measure jaw BMD in dentistry and may soon replace MSCT, which is expensive and requires special facilities.

• The Korean Journal of Pain
• /
• v.18 no.2
• /
• pp.133-137
• /
• 2005

Background: Cannabinoids have shown antinociceptive action. The aims of this study were to examine the effect of chronic infusion of a cannabinoids receptors agonist (WIN 55,212-2) for thermal nociception at the spinal level, and to also observe the development of toxicity. Methods: Male Sprague-Dawley rats were implanted with lumbar intrathecal catheters with the nociceptive response (withdrawal response latency) determined by exposing the plantar surface of the hindpaw to radiant heat. Initially, the effect of intrathecal WIN 55,212-2 was evaluated followed by the change in the effect at 1, 2, 3 and 4 weeks after repeated infusion. Finally, the histopathological findings were assessed 1 and 4 weeks following the infusion of WIN 55,212-2. Results: Intrathecal WIN 55,212-2 was found to produce a limited antinociception during the thermal test. %MPE of WIN 55,212-2 at 1, 2, 3, and 4 weeks after infusion was not different from each other. No abnormal pathological findings were observed following a chronic intrathecal infusion of WIN 55,212-2. Conclusions: WIN 55,212-2, a cannabinoids receptors agonist, may be useful in the management of thermal nociception, without changing the effectiveness or causing the toxicity following a chronic infusion at the spinal level.

• Journal of Environmental Impact Assessment
• /
• v.25 no.6
• /
• pp.369-383
• /
• 2016

A distributed watershed model CAMEL(Chemicals, Agricultural Management and Erosion Losses) was applied to a part of grazing grassland and vegetation buffer strip(VBS) located in Daegwanryeong, Korea. A set of scenario analyses was carried out for grassland and VBS with various combinations of VBS widths, soil textures and ground surface slopes. The simulation results indicate that annual direct runoff decreases with wider VBS and the removal efficiency of pollutants generally decrease with steeper slopes. The removal efficiency of sediment is not significantly different with VBS widths. For gentle and medium slopes($10^{\circ}$, $20^{\circ}$), the removal efficiency of TOC and TN is not significantly different with VBS widths. As for a steep slope($30^{\circ}$), however, the removal efficiency of TOC and TN increases with narrower VBS. The removal efficiency of TP is generally high except for medium and steep slope of sandy loam where the removal efficiency of TP increases with wider VBS. This result of TP is contrary to the results of TOC and TN due to the adsorption characteristics of phosphorus associated with fine sediment particles. It is expected that CAMEL can be used for evaluating the effectiveness of VBS to reduce non-point source pollution discharges.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.6
• /
• pp.1201-1206
• /
• 2009

According to a lot of investigations, distance perception is influenced by many important cues such as sound pressure level, reflections from the room surface, binaural difference (ITD and ILD), a kind of sound source, and head related transfer functions (HRTF). Two psychoacoustical experiments on auditory distance perception were conducted to examine the effectiveness of the sound pressure level loudness as one of the physical cues in the auditory distance perception under a constant loudspeaker's output level and a constant sound level at the subject's position in the absence of reflections in an anechoic room. Our experimental results showed that the perceived distance of sound image is closer than actual sound source distance with the constant loudspeaker's output level and the constant sound level. Futhermore, the perceived distance of a sound image with constant sound level increased when the actual distance increases up to approximately 2 m while the perceived distance saturated when the sound source distance exceed 2 m. On the other hand, when the condition of loudspeaker's output level was kept constantly, the perceived distance of sound image increased up to around 3m, longer than the conditions of constant sound level at the subject's position. We found that the change in the loudness as a function of distance plays an important role in the auditory distance perception in the absence of reflections..

• Korean Journal of Oriental Medicine
• /
• v.18 no.3
• /
• pp.103-110
• /
• 2012

Objectives : Fire needling has been applied as the treatment for various diseases and been getting much attention from Oriental medicine due to its excellent effectiveness as the results of clinical studies have reported. However, the research findings on the safety of treatment method, materials for the Fire needling needle materials and the possibility of burn injury during the procedure are still insufficient. Methods : A thermo imaging camera was used to confirm the temperature distribution on acupuncture needle and the treatment area during the fire needling therapy. Then the degree of thermal injury was observed by H&E stain and TUNEL assay. In addition, in order to assess the safety of acupuncture materials, we conducted MTT assay using a L6 cell line. Results : The average temperature of the skin surface was observed at $47{\sim}51^{\circ}C$ after classic fire needling and $30^{\circ}C$ after warming fire needling. Warming fire needling therapy does not induce a burn on the tissue and a third degree burn was observed locally in the muscle and skin layers after classic fire needling treatment. This confirms that hwa-acupuncture therapies do not cause major burns. According to the safety assessment test result, no cytotoxicity was detected in the warming fire needling materials. This confirms the safety of the acupuncture materials Conclusions : Various research results on the biological safety of fire needling. Since fire needling therapy induces a burn locally without leaving any scar, and as other results indicate, it is considered a safe treatment method.