• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.12
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• pp.1034-1038
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• 2007

In order to develop the composition ceramics capable of being sintered at low temperature with high piezoelectric properties for multilayer piezoelectric actuator application, PZW-PMN-PZT system ceramics were manufactured according to sintering aid $Li_2CO_3$ addition and their microstructural, dielectric and piezoelectric properties were investigated. The crystal structure of the specimens showed a perovskite phase and no pyrochlore or other second phase was detected. At the sintering temperature of $900\;^{\circ}C,\;0.2\;wt%Li_2CO_3$ added specimen showed a optimum values of kp = 0.562, $d_{33}\;=\;360\;pC/N$ and Qm = 1184, respectively.

• Journal of Urban Science
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• v.7 no.2
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• pp.53-60
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• 2018

Digital Twin is a technology that creates a photocopy of real-world objects on a computer and analyzes the past and present operational status by fusing the structure, context, and operation of various physical systems with property information, and predicts the future society's countermeasures. In particular, 3D rendering technology (UAS, LiDAR, GNSS, etc.) is a core technology in digital twin. so, the research and application are actively performed in the industry in recent years. However, UAS (Unmanned Aerial System) and LiDAR (Light Detection And Ranging) have to be solved by compensating blind spot which is not reconstructed according to the object shape. In addition, the terrestrial LiDAR can acquire the point cloud of the object more precisely and quickly at a short distance, but a blind spot is generated at the upper part of the object, thereby imposing restrictions on the forward digital twin modeling. The UAS is capable of modeling a specific range of objects with high accuracy by using high resolution images at low altitudes, and has the advantage of generating a high density point group based on SfM (Structure-from-Motion) image analysis technology. However, It is relatively far from the target LiDAR than the terrestrial LiDAR, and it takes time to analyze the image. In particular, it is necessary to reduce the accuracy of the side part and compensate the blind spot. By re-optimizing it after fusion with UAS and Terrestrial LiDAR, the residual error of each modeling method was compensated and the mutual correction result was obtained. The accuracy of fusion-based 3D model is less than 1cm and it is expected to be useful for digital twin construction.

• Metals and materials international
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• v.24 no.6
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• pp.1359-1368
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• 2018

The mechanical properties and microstructure evolution of Mg-8Li-3Al-1Y alloy undergoing different rolling processes were systematically investigated. X-ray diffraction, optical microscope, scanning electron microscopy, transmission electron microscopy as well as electron backscattered diffraction were used for tracking the microstructure evolution. Tensile testing was employed to characterize the mechanical properties. After hot rolling, the $MgLi_2Al$ precipitated in ${\beta}-Li$ matrix due to the transformation reaction: ${\beta}-Li{\rightarrow}{\beta}-Li+MgLi_2Al+{\alpha}-Mg$. As for the alloy subjected to annealed hot rolling, ${\beta}-Li$ phase was clearly recrystallized while recrystallization rarely occurred in ${\alpha}-Mg$ phase. With regard to the microstructure undergoing cold rolling, plenty of dislocations and dislocation walls were easily observed. In addition, the microstructure of alloys subjected to annealed cold rolling revealed the formation of new fresh ${\alpha}-Mg$ grains in ${\beta}-Li$ phase due to the precipitation reaction. The mechanical properties and fracture modes of Mg-8Li-3Al-1Y alloys can be effectively tuned by different rolling processes.

• Korean Journal of Oriental Medicine
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• v.13 no.3
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• pp.1-10
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• 2007

This study is on the characteristics of LiSangSockDanBang(理傷續斷方). Through this study, the characteristics of LiSangSockDanBang(理傷續斷方) can be oganized as the following: First of all, in LiSangSockDanBang, the treatment of traumatic injury is consisted of the fourteen steps. This fourteen steps is resorted by four steps. ; Washing(洗藥法), Standin in line(整復法), Using an external application(外治法), Using an internal medicine(內服法). This is LiSangSockDanBang's major characteristics. Because of this contents, LiSangSockDanBang is quoted on EuiBangLyuChi(醫方類聚). The first treatment of traumatic injury is Wahing. Wahing is not only sterilizing a wounded region but pushing out the PungSa(風邪). So, to avoid a infection of a tetanus, washing medicine consist of the herbs, that push out the PungSa(風邪). LiSangSockDanBang has high level of surgery. In 1456, YoungLyuGumBang(永類鈐方), has no more level than surgery's in LiSangSockDanBang, is reprinted. This fact means that the surgery is used frequently in those days. In this scientific backing, an operation needle, that described in ChiJongJiNam(治腫指南) and ChiJongBiBang(治腫秘方), are written by Lim UnGook(任彦國), is used frequently, too. In LiSangSockDanBang, the major external applications are HookLyongSan(黑龍散) and PungLyuSan(風流散). In case of open wound, the HookLyongSan is used but in closed wound, PungLyuSan is used. The internal medicine has three applications. ; Removing extravasated blood(瘀血), Catharsis(通利大小便), Supplementation(補氣血).

• Journal of the Korean Ceramic Society
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• v.41 no.8
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• pp.593-598
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• 2004

To make the all-solid-state lithium thin film battery having less than 1 fm in thickness, LiCoO$_2$ thin films were deposited on Pt/TiO$_2$/SiO$_2$/Si substrate as a function of Li/Co mole ratio and the deposition temperature by Pulsed Laser Deposition (PLD). Especially, LiCoO$_2$ thin films deposited at 50$0^{\circ}C$ with target of Li/Co=1.2 mole ratio show an initial discharge capacity of 53 $\mu$Ah/cm$^2$-$\mu$m and capacity retention of 67.6％. The microstructural and electrochemical properies of (Li, La)TiO3 thin films grown on LiCoO$_2$Pt/TiO$_2$/SiO$_2$/Si structures by Pulsed Laser Deposition (PLD) were investigated at various deposition temperatures. The thin films grown at 10$0^{\circ}C$ show an initial discharge capacity of approximately 51 $\mu$Ah/cm$^2$-$\mu$m and moreover show excellent discharge capacity retention of 90％ after 100 cycles. An amorphous (Li, La)TiO$_3$ solid electrolyte is possible for application to solid electrolyte for all-solid-state lithium thin film battery below 1 $\mu$m.

• The Journal of Korean Philosophical History
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• no.50
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• pp.113-138
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• 2016

The purpose of this research is to establish the foundation for understanding the appearance of development, inheritance and acceptance of Toegye Yi Hwang(退溪李滉, 1501~1570)'s theory after his life by examining Udam Jeong Sihan(愚潭 丁時翰, 1625~1707)'s view on the Ido-seol(理到說), the Toegye's latter theory. After Toegye, Ido-seol was translated as 'The principle of matters reaches the human mind'. Galam Yi Hyunil(葛庵 李玄逸, 1627~1704), the contemporary scholar with Udam, criticized this translation for applying the directivity and motility to 'Li', the immovable principle. However, Udam agreed with the conventional interpretation of Ido-seol and understood it as the consilience of mind which got the entire principle(體) of 'Li(理)' and contained the application(用) of all things. He extended this concept as the level of 'sameness between objects and self [物我爲一]' based on his former theory, the exquisite interpretation of 'application of Li'. The meaning of 'sameness between objects and self[物我爲一]' is not amalgamation but applepie order of matter's principle in mind. The Udam's viewpoint is differ from Galam who tried to overcome the structural limit of Ido-seol by transforming 'Do(到)', the predicate of 'Ido(理到)', into 'Jin(盡)'. It means that he tried to interpret 'Ido(理到)' on the more essential aspect. His view can be the useful tool for understanding the Toegye's neo-Confucianism system with 'Li(理)' as central figure. It suggested that Udam's theory of the principle and the applecation of 'Li' can be the important theory to investigate the formation of Toegye schools' though and its development.

• Journal of Sensor Science and Technology
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• v.23 no.1
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• pp.42-45
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• 2014

Recently, tremendous application utilizing electrospun nanofibers have been actively reported due to its several advantages, such as high surface to volume ratio, simple fabrication and high-throughput manufacturing. In this paper, we developed highly sensitive and consistent nanofiber humidity sensor by electrospinning. The humidity sensor was fabricated by rapid electrospinning (~2 sec) $TiO_2$/PVP/LiCl mixed solution on the micro-interdigitated electrode. In order to evaluate the humidity sensing performances, we measured current response using DC bias voltage under various relative humidity levels. The results show fast response / recovery time and marginal hysteresis as well as long-term stability. In addition, with the aid of micro-interdigitated electrode, we can reduce a total resistance of the sensor and increase the total reaction area of nanofibers across the electrodes resulting in high sensitivity and enhanced current level. Therefore, we expect that the electrospun nanofiber array for humidity sensor can be feasible and promising for diverse humidity sensing application.

• Journal of the Microelectronics and Packaging Society
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• v.10 no.2
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• pp.13-17
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• 2003

In this study, new LTCC materials of $ZnWO_4$-LiF system were developed for the application to RF Module fabrication. Pure $ZnWO_4$ must be sintered above $1050^{\circ}C$ in order to obtain up to 98% of full density. The measured dielectric constant ($\epsilon_r$)quality factor ($Q{\times}f0$), and temperature coefficient of resonant frequency ($\tau_f$ were 15.5, 74000 GHz, and $-70ppm^{\circ}C$, respectively. LiF addition resulted in a liquid phase formation at 81$0^{\circ}C$ due to interaction between ZnWO$_4$ and LiF. Therefore, ZnWO$_4$ with 0.5∼1.5 wt% LiF could be densified at $850^{\circ}C$. In the given LiF addition range, the sintering shrinkage increased with increasing LiF content. Addition of LiF slightly lowered the dielectric constant from 15.5 to 14.2∼15 due to lower dielectric constant of LiF. Qxfo value decreased with increasing LiF content. This can be explained in terms of the interaction between LiF and $ZnWO_4$, and inhomogeneity of grain structure.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2009.04a
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• pp.291-292
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• 2009

항공레이저측량(LiDAR)는 대상물에 반사되어 오는 레이저를 이용하여 멀리 위치한 대상물의 정보를 측정하는 광학원격탐사기술이다. 항공기에 레이저센서를 장착, 지표면에 레이저 펄스를 주사하여 반사된 펄스의 도달시간을 측정, 반사지점의 3차원 위치좌표를 계산하여 지표면의 정보를 추출한다. 항공레이저측량(LiDAR)는 재난재해관리, 도로 및 교통, 시설물계획관리, 지역지구 계획 등에 활용할 수 있다. 또한 항공사진과 GIS를 활용함으로서 실세계의 3차원 표현이 가능하며 실세계를 인터넷, PDA 및 핸드폰 등에 3차원으로 표현하는데 필요한 데이터베이스를 제공할 수 있다. 이는 도래하는 유비쿼터스 시대에 필요한 정확하고 정교한 데이터기반을 구성한다.

• Journal of Electrochemical Science and Technology
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• v.12 no.1
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• pp.126-136
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• 2021

The electrochemical performance of all-solid-state cells (ASSCs) based on sulfide electrolytes is critically affected by the undesirable interfacial reactions between oxide cathodes and sulfide electrolytes because of the high reactivity of sulfide electrolytes. Based on the concept that the interfacial reactions are highly dependent on the type of sulfide electrolyte, the electrochemical properties of the ASSCs prepared using three types of sulfide electrolytes were observed and compared. The Li2MoO4-LiI coating layer was also introduced to suppress the interfacial reactions. The cells using argyrodite electrolyte exhibited a higher capacity and Coulombic efficiency than the cells using 75Li2S-22P2S5-3Li2SO4 and Li7P3S11 electrolytes, indicating that the argyrodite electrolyte is less reactive with cathodes than other electrolytes. Moreover, the introduction of Li2MoO4-LiI coating on the cathode surface significantly enhanced the electrochemical performance of ASSCs because of the protection of coating layer. Pulverization of argyrodite electrolyte is also effective in increasing the capacity of cells because the smaller size of electrolyte particles improved the contact stability between the cathode and the sulfide electrolyte. The cyclic performance of cells was also enhanced by pulverized electrolyte, which is also associated with improved contact stability at the cathode/electrolyte. These results show that the introduction of Li2MoO4-LiI coating and the use of pulverized sulfide electrolyte can exhibit a synergic effect of suppressed interfacial reaction by the coating layer and improved contact stability owing to the small particle size of electrolyte.