• Journal of Plant Biology
• /
• v.37 no.2
• /
• pp.203-221
• /
• 1994

Pollen grains of 19 taxa belonging to 12 genera in 5.families of the Korean gymnosperms were investigated by LM, SEM and TEM, and their morphological characters were described and palynological keys were made for each family. From the taxonomic viewpoint, palynological characters are very available to intergeneric and intrageneric classifications since their distinctive differences in pollen shape, size, condition of surface, sculpture pattern and presence of air bladders and projection except for the intrageneric classification of the genus Pinus since the overlapped characters such as pollen size and sculpture pattern. Pollen grains of Picea koraiensis in the family Pinaceae are distinguished from thc genera Pinus and Abies for the reasons that shape of air bladders are irregular, air bladders are bigger than pollen body, and pollen wall is thin. Compared with the genera Abies and Pinus that have air bladders, Picea koraiensis is closely related to Abies in that pollen body wall become gradually thin from pole of proximal face to air bladder, surface of pollen body is not rough, and pollen size is similar to that of the genus Abies. The presence of ektexine and enexine in proximal face, and the connections of the former to air bladder wall and the latter to distal face were elucidated by the investigation of pollen grains with air bladders through TEM. Endexine of the families of Taxaceae, Taxodiaceae and Cupressaceae was also obse-rved as a pile of laminae. From the observation by SEM, sculpture pattern of air bladder was foveolate with fine pits on surface. Sculpture pattern of air bladder is reticulate under LM, but observed by TEM, it resulted from the transmission of netted structure in air bladder.

• Journal of Power System Engineering
• /
• v.20 no.4
• /
• pp.75-82
• /
• 2016

In this paper, we developed a 3D printing system using a photo-curing resin in order to reduce the surface roughness of a sculpture produced with the 3D printer. Using the pattern of the resulting variable thickness, that gave rise to a stepped shape, and the area error of the photo-curable sculpture, a study was carried out for the process to reduce the surface roughness. At a given value of stage velocity (40~70 mm/s) and output air pneumatic pressure (20~60 kPa), the minimum pattern thickness of the pattern was achieved $65{\mu}m$ and the maximum pattern thickness of up to $175{\mu}m$. To increases the pattern resolution to about $40{\mu}m$, the process conditions should be optimized. 3D surface Nano profiler was used to find the surface roughness of the sculpture that was measured to be minimum $4.7{\mu}m$ and maximum $8.7{\mu}m$. The maximum surface roughness was reduced about $1.2{\mu}m$ for the maximum thickness of the pattern. In addition, a FDM was used to fabricate the same sculpture and its surface roughness measurements were also taken for comparison with the one fabricated using photo-curing. Same process conditions were used for both fabrication setups in order to perform the comparison efficiently. The surface roughness of the photo-curable sculpture is $5.5{\mu}m$ lower than the sculpture fabricated using FDM. A certain circuit patterns was formed on the laminated surface of the photo-curable sculpture while there was no stable pattern on the laminated surface of the FDM based sculpture the other hand.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.13 no.3
• /
• pp.11-17
• /
• 2017

The aerial support air sculptures currently exhibited in indoor spaces are similar to simple ad balloons, using multiple rope strands. Users now want more advanced unfixed sculptures, and hope these will develop into buoyant sculptures that can maintain the attitudes that users want on their own. This study investigated an attitude control system for unfixed levitation sculptures that can levitate with no rope and continuously maintain a certain attitude at a height specified by the user. To facilitate levitation, the exterior part of the sculpture was made of lightweight fibers, and the interior part was filled with helium gas. The controller was composed of a microprocessor of the dsPIC30F line from microchip, gyro, acceleration, and earth magnetic field sensors, and a highly efficient brushless DC (BLDC) electric motor. The attitude and position control system requires scheduling considering the trajectories of the sculpture and the control system, because the roles of the overall components are more important than those of a single controller. Furthermore, the system was designed like a fusion system that is expanded and controlled as a total controller, because it is interconnected with various sensors. The attitude control system of buoyant sculptures was implemented in this study, such that it can actively cope with the position, direction, stopping, and time aspects. The system performance was then evaluated.

• Journal of the Korea Society of Computer and Information
• /
• v.27 no.2
• /
• pp.9-14
• /
• 2022

In this study, we propose a method for moving a device such as a flexible air sculpture while stably maintaining the user's desired posture. To accomplish this, a robot system with a structure of a mobile robot capable of running according to a given trajectory was studied by applying the PI algorithm and horizontal maintenance posture control using IMU. The air sculptures used in this study often use thin strings in a fixed posture. Another method is to put a load on the center of gravity to maintain the posture, and it is a system with flexibility because it uses air pressure. It is expected that these structures can achieve various results by combining flexible structures and mobile robots through the convergence process of digital sensor technology. In this study, posture control was performed by fusion of the driving technology of AGV(Automatic Guided Vehicle),, a field of robot, and technologies applying various sensors. For verification, the given performance evaluation was performed through an accredited certification test, and its validity was verified through an experiment.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.14 no.4
• /
• pp.1-7
• /
• 2018

The floating sculptures in the form of ad-ballon commonly used ropes in order to hold on. Relatively air flow is much less indoor than outdoor. Users of buoyancy sculptures hope to be able to maintain their desired posture without being fixed. This study applied drone technology to buoyancy sculptures. The drones can be moved vertically and horizontally, and the posture can be maintained, so buoyancy sculptures are easy to apply. Therefore, we have studied the control system of buoyancy sculpture using drone technology. Also, a control system that can maintain the desired posture at a constant height was studied. The overall shape was a light fiber material and helium gas for zero buoyancy to support the sculpture. The system configuration was STM32F103CB from ARM. In addition, the gyro and acceleration, geomagnetic sensors and motors are composed of small and medium size BLDC motors. The scheduling of the control system in the configuration of the control device was carefully considered. Because the role of the whole component becomes very important. The communication between the components is divided into the sensor fusion and the interface communication with the whole controller. Each communication technology is designed to expand. This study was implemented to actively respond from the viewpoint of posture control using the drone technology.

• Journal of Conservation Science
• /
• v.33 no.2
• /
• pp.121-130
• /
• 2017

The currently used wax agents for preserving outdoor metal structures, despite their advantages, have disadvantages such as low endurance and reliability. These wax agents are easily damaged by acid rain, dust, moisture in the air, yellow dust, and air pollutants, resulting in corrosion within a short period after the initial conservation treatment. In addition, aged wax can also exhibit changes in the color or gloss, and also give a sense of difference in the surface. Given these existing problems, it is necessary to develop improved materials for metal preservation. Therefore, this study analyzed the characteristics and applications of the existing wax coating agents in order to identify their disadvantages and to develop a better material for metal preservation. In this regard, this study developed a perilla oil based compound wax and conducted experiments to test its endurance. The new compound wax agent was exposed to outdoor and acid rain conditions: it showed four times and 1.5 times the endurance of the existing wax agents in outdoor and acid rain conditions, respectively. In addition, the new agent seems to be more durable and protective as evidenced by the chromaticity, polish maintenance, and contact angle results. Further, although it is 1.3-1.8 times thicker than the existing agents, the new agent shows a more even surface. Based on these findings, it can be concluded that the new compound wax agent based on perilla oil is a better alternative to the existing was coating agents.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2016.07a
• /
• pp.235-236
• /
• 2016

본 연구에서는 고 성능 마이크로프로세서를 이용한 공기조형물의 관절 구동과 센서의 환경 인식에 능동적으로 대처할 수 있는 시스템을 연구하였다. 객체기반의 공기조형물용 모션제어 시스템은 단일 제어기로의 역할보다 시스템 구성요소로서의 역할이 매우 중요해지므로 시스템 전체의 제어기로 확장시켜 사용하는 방향으로 전환되어야 한다. 본 연구에서는 시스템의 구동과 환경에 능동적으로 대처할 수 있는 객체기반 공기조형물을 연구하였다. 모터제어 방법에 있어 CAN(Controller Area Network) 네트워크를 방식을 통하여 제어를 수행하는 분산제어방식으로 수행하였다. CAN방식은 모션제어 시스템에 도입하여 주 제어기가 하위 제어기에 네트워크를 통하여 명령을 내리며 하위제어기는 주어진 위치 및 속도명령에 대하여 분산적으로 제어를 수행하였다. 따라서 CAN방식을 사용하여 각 제어기의 독립성과 처리속도를 증대시키고 공기조형물의 기능별 확장이 용이하도록 구성하였다. 제어기의 환경은 시스템을 총체적으로 조화롭게 제어할 수 있는 시스템으로의 역할이 중요시되어 이에 맞도록 설계방안을 연구하였다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2017.11a
• /
• pp.415-417
• /
• 2017

국내의 도시화와 중국에서 넘어오는 오염물질에 의하여 대기오염에 대한 피해가 갈수록 커져가고 있다. 하지만 대기오염 집중측정소 6곳에서만 초미세먼지의 구성 성분을 실시간으로 측정하고 있고 그에 대한 자료를 공개하지 않는 것으로 알려져 있다 [1]. 또한 정부는 서비스 개발 및 제공 과정에서 공공성에 대한 고려도 중요하지만, 그것이 얼마나 시민들의 수요나 관심과 결부되어 있는지에 대한 고민도 함께 요구된다. 특히 서울특별시와 같이 대도시에서 거주하는 시민들의 주된 관심사 중 대기오염과 관련한 관심은 지속적으로 높아지고 있다 [2]. 본 논문은 6가지의 센서가 내장된 LED 조형물을 실생활 공간에 배치하고 조형물, 모바일, 웹에서 정보를 실시간으로 제공하는 대기오염 정보 제공 시스템을 제안할 것이다. 일반 대기 측정소와 다른 LED 조형물을 통하여 시민들의 접근성과 편리함을 향상시킬 수 있는 새로운 방식의 대기오염 정보 제공 시스템을 기대해볼 수 있을 것으로 예상된다.

• Journal of the Korea Convergence Society
• /
• v.9 no.4
• /
• pp.151-160
• /
• 2018

Waxes currently used as a coating material to preserve surfaces of outdoor iron sculptures tend to face lower coating strength and efflorescence due to the aging from air pollution and acid rains. Consequently, they are subjected to repeated corrosions shortly after the treatment. And the sculptures face the problem losing their original nature because of the changes of colors and lusters, so this convergence study aims at developing wax with better performance than the existing materials. For this reason, the study identified the effects of physical property using the environmental experiments such as the tests of salt spray and gas corrosion as well as the analysis of luster level and thermo-gravimetry. As this study result, the developed ISC wax showed the excellent blocking effect from salt water and coating durability more than five times compared with the existing waxes, better acid resistance by two-four times, sun block effect by 2-10 times, improved luster variance by 3-16 times, improved thermo-stability and durability by 0.5-5 times, and therefore demonstrating far better coating effect than the existing waxes. In the light of these findings, this study contributes for this new development which can replace the existing waxes used so far in order to preserve the outdoor iron sculptures.

• The Journal of Art Theory & Practice
• /
• no.9
• /
• pp.151-170
• /
• 2010

As an art group, De Stijl (1917-1931) led a total art movement encompassing painting, sculpture, design, and architecture. Among these, architecture, as a model of the total art pursued by the group, was encapsulated by the term 'plastic architecture.' The term reflects architecture's shared features with plastic art, especially its pictorial characteristics. Firstly, De Stijl architecture shares geometric form with painting. Assembled in simple, clear and rational structures, the geometric forms signified universal forms, and extended the pictorial experimentation that Mondrian exercised through Neo-Plasticism to architecture. Constructed with colour fields made of concrete wall, De Stijl architecture is geometric abstract painting embodied in space. Together with such pictorial characteristics, large plate glass windows, narrow window frames, and cantilever structure minimize the building's visual weight. De Stijl architecture, which appears suspended in the air, is an architectural version of the abstract paintings of the era that revealed unknown spaces beyond perspective. De Stijl architecture is also an 'open' architecture, where the units placed as if radiating from the center form relations with each other flexibly and organically. The observer in such a space is encouraged to experience space within time, as his/her physical and visual mobility and extension are maximized. De Stijl architecture is an example of how the time-space continuum, represented within picture frame through Cubism, Futurism, and abstract art, can be realized in space. By transforming the ideal space of painting into real space in this way, 'plastic architecture' turned out to be an architectural manifestation of the utopianism of the era, aimed at building a society in 'perfect harmony.' However, such rationalism and universalism are not free from the violence of totalization that deletes various differences. This is evident in the history that followed as the geometric form of architecture and urban planning proliferated across the globe, engulfing the diverse natural landscapes and local cultures.