• The Journal of Engineering Geology
• /
• v.33 no.3
• /
• pp.413-426
• /
• 2023

This study presents the geochemical characteristics of cave water to evaluate its origin and flow path. From June 2022 to may 2023, river water was collected at two sites (WE1 and WE2) in the Donggang River around Baengnyongdonggul Cave, and cave water was collected at four sites (WE3 to WE6) inside Baengnyongdonggul Cave. Water samples were analyzed for major dissolved components. Both river and cave waters were classified as Ca-HCO₃ type. All cave water samples were supersaturated in carbonate minerals, suggesting that carbonate minerals would precipitate within the cave. Due to differences in the source of cave water and the degree of water-rock interaction, the geochemical characteristics of water from sites where the flow of cave water is observed (WE3 and WE6) and rimstone pools (WE4 and WE5) could be clearly distinguished. The cave water at WE6 flows in from the Donggang River, then passes through WE3 and flows back out into the Donggang River. The cave water at WE4 and WE5 is supplied from precipitation, but the flow path of cave water at WE4 and WE5 is different.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.81-81
• /
• 2000

We use camera to apply human vision system in measurement. To do that, we need to know about camera parameters. The camera parameters are consisted of internal parameters and external parameters. we can fix scale factor&focal length in internal parameters, we can acquire external parameters. And we want to use these parameters in automatically driven vehicle by using camera. When we observe an camera parameters in respect with that the external parameters are important parameters. We can acquire external parameter as fixing focal length&scale factor. To get lane coordinate in image, we propose a lane detection filter. After searching lanes, we can seek vanishing point. And then y-axis seek y-sxis rotation component(${\beta}$). By using these parameter, we can find x-axis translation component(Xo). Before we make stepping motor rotate to be y-axis rotation component(${\beta}$), '0', we estimate image coordinates of lane at (t+1). Using this point, we apply this system to Kalman filter. And then we calculate to new parameters whick make minimum error.

• The Mathematical Education
• /
• v.47 no.1
• /
• pp.49-59
• /
• 2008

In this paper, we discuss two representations of a curve. One is a static representation as set of points, the other is a dynamic representation using time parameter. And we suggest needs of designing a computer microword where we can represent a curve both statically and dynamically. We also emphasize the importance of translation activity from a static representation to a dynamic representation. For this purpose, we first consider constructionism and 'computers and mathematics education' as a theoretical backgrounds. We focus the curve of a parabola in this paper since this is common in mathematics curriculum and is related to realistic situation such as throwing ball. And we survey the mathematics curriculum about parabola representation. And we introduce JavaMAL microworld that is integrated microworld between LOGO and DGS. In this microworld, we represent a parabola using a dynamic action, and connect this dynamic parabola action to recursive patterns. Finally, we remake a parabola for a realistic situation using this dynamic representation. And we discuss the educational meaning of dynamic representation and its computer microworld.

• The Mathematical Education
• /
• v.45 no.2 s.113
• /
• pp.165-176
• /
• 2006

In this paper, we consider changes of algebra strands around the world. And we suggest needs of designing new computer environment where we make and manipulate geometric recursive patterns. For this purpose, we first consider relations among symbols, meanings and patterns. And we also consider Logo environment and characterize algebraic features. Then we introduce L-system which is considered as action letters and subgroup of turtle group. There are needs to be improved since there exists some ambiguity between sign and action. Based on needs of improving the previous L-system, we suggest new commands in JavaMAL microworld. So we design a microworld for recursive patterns and consider meanings of letters in new environments. Finally, we consider the method to integrate L-system and other existing microworlds, such as Logo and DGS. Specially, combining Logo and DGS, we consider the movement of such tiles and folding nets by L-system commands. And we discuss possible benefits in this environment.

• Natural Product Sciences
• /
• v.13 no.4
• /
• pp.347-354
• /
• 2007

In this study, we investigated the potential of Resina Pini (RP) for anti-inflammatory and analgesic agents to treat inflammatory diseases such as gingivitis and periodontitis. Crude RP (RP1), recrystallized RP (RP2), and Ramus Mori Albae-treated RP (RP3), plus their respective water extracts (RP1-WE, RP2-WE and RP3-WE) were prepared for in vitro and in vivo tests. We couldn't find any signs of heavy metals pollution in all the RP samples. RP2-WE exhibited the highest viability of human gingival fibroblasts (HGF) and the strongest scavenging activity on superoxide anion. RP1, RP2 and RP3, RP2 showed potent scavenging activity on DPPH free radical. RP2-WE displayed a stronger inhibition on hyaluronidase (HAase) activity and RP3 also displayed potent HAase inhibition. RP2-WE, RP3-WE, RP3 and RP2 were reduced admirably the production of $PGE_2$ in HGF. In addition, RP2-WE and RP3-WE exhibited potent inhibitory activities on arachidonic acid-induced ear edema in mouse. Moreover, RP-2 prevented completely acetic acid-induced writhing by 100.0% and RP1, RP3, RP1-WE and RP2-WE also exhibited excellent protective activities against writhing. While aminopyrine, the positive control, showed 76.9% analgesic effect at the same dose. Taken together, these results suggest that recrystallized aqueous extract of Resina Pini could be a promising drug for the treatment of periodontal diseases.

• Transactions on Electrical and Electronic Materials
• /
• v.18 no.2
• /
• pp.59-61
• /
• 2017

This research was analyzed thermal characteristics that was appointed disadvantage when smart LED driver ICs was packaged and we applied extracted thermal characteristics for optimal layout design. We confirmed reliability of smart LED driver ICs package without additional heat sink. If the package is not heat sink, we are possible to minimize package. For extracting thermal loss due to overshoot current, we increased driver current by two and three times. As a result of experiment, we obtained 22 mW and 49.5 mW thermal loss. And we obtained optimal data of 350 mA driver current. It is important to distance between power MOSFET and driver ICs. If the distance was increased, the temperature of package was decreased. And so we obtained optimal data of 3.7 mm distance between power MOSFET and driver ICs. Finally, we fabricated real package and we analyzed the electrical characteristics. We obtained constant 35 V output voltage and 80% efficiency.

• Proceedings of the ESK Conference
• /
• 1995.04a
• /
• pp.25-29
• /
• 1995

When we design a product, we need to consider human sensibility for the product. In this study, we developed a technique to measure human sensibility for a product. Because human sensibility for a product is very subjective and fuzzy, it is hard to measure easily. To deal with this difficulty effectively, we used fuzzy-weighted checklist to this problem. The fuzzy- weighted checklist presents a fuzzy version of the weighted checklist technique computerized for evaluating or comparing complex system (or subjects). In this technique, we used pairwise comparison to get the relative weights of wensibility factors. Also, we used linguistic ratings to get the scores of sensibility factors for a product. Then, we synthesize the scores of sensi- bility factors to get fuzzy composite score (and linguistic approximation). If there are several alternatives, we can conduct alternative comparison. Finally, we wrote the program of this technique by Quick Basic software. As an example, this technique applied to car. The results show that we can use this technique effectively to the quantitative evaluation of human sensibility

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.05a
• /
• pp.560-563
• /
• 2004

This study reports the site application of concrete using AE Water Reducing Agent of Early-Strength Type. According to the lab test results, we have made plans of batch plant pilot test, and we have analyzed the erly aged compressive strength and workability of the concrete. We applied the early-strength development concrete to the construction site. We accomplished the slump test in order to evaluate the workablity and air contents, we made site curing mold to evaluate the early strength of members. As a result, we judgeed the superior property of early strength development of the concrete, and thought that we can reduce the time of form stripping more $40\%$ than ordinary strength concrete. We thought that we can reduce the term of works and finally we can accomplish the economical construction.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.29 no.2
• /
• pp.79-83
• /
• 2016

This research was analyzed thermal characteristics that was appointed disadvantage when smart LED driver ICs was packaged and we applied extracted thermal characteristics for optimal layout design. We confirmed reliability of smart LED driver ICs package without additional heat sink. If the package is not heat sink, we are possible to minimize package. For extracting thermal loss due to overshoot current, we increased driver current by two and three times. As a result of experiment, we obtained 22 mW and 49.5 mW thermal loss. And we obtained optimal data of 350 mA driver current. It is important to distance between power MOSFET and driver ICs. If thhe distance was increased, the temperature of package was decreased. And so we obtained optimal data of 3.7 mm distance between power MOSFET and driver ICs. Finally, we fabricated real package and we analyzed the electrical characteristics. We obtained constant 35 V output voltage and 80% efficiency.

• Journal of the Semiconductor & Display Technology
• /
• v.18 no.3
• /
• pp.25-30
• /
• 2019

In this paper, we have analyzed manufacturing problems of the scaffold with pores using FDM 3D printer and PLGA. We suggested the solutions using 3SC practical TRIZ. We selected the final solution used machine learning. We reduced number of experiments using most influential factor after analysis print factors. We printed the scaffold and measured pore size. We created the regression model using python tensorflow. The print condition data of measured pore size was used as training data. We predicted the pore size of printed condition using regression model. We printed the scaffold using the predicted the print condition data. We quantitatively compare the predicted scaffold pore size data and the measured scaffold pore size data. We got satisfactory result.