• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.24 no.10
• /
• pp.130-135
• /
• 2010

In this paper, the shading ratio about to output the minimum critical power of a photovoltaic panel was determined by experiment and simulation. A 2.475[kW] poly-crystalline photovoltaic panel consisting of 11 modules was used in the experiment and its surface was covered with shading curtains, thus the amount of light incident to the modules were controlled. In order to compare with the experimental results, the experimental circuits were modelled with the CASPOC (power electronics electrical drives simulator) and module parameters were applied to it, by which the minimum critical power was calculated. As a result, the photovoltaic panel was about to generate the power when the 5th shading curtains were removed from the module surface, after then the output power linearly increased by removing the shading curtains. In addition, the CASPOC simulation results were similar to the experimental results in the abrupt decreasing pattern of power.

• Transactions on Electrical and Electronic Materials
• /
• v.18 no.3
• /
• pp.176-179
• /
• 2017

Non-vacuum processing technology was used to produce $Cs_3Sb$ photocathodes on substrates and fabricate in-situ panel devices. Electrical properties of these panel devices were characterized by measuring anode current and charge dose as functions of devices operation time. An excitation light source with a 475 nm wavelength was used for photocathodes. Results showed that emission properties of these photocathode emitters depended heavily on the vacuum level of these devices and that $Cs_3Sb$ flat emitters had the potential of operating for a long lifetime with stable electron emission characteristics via re-cesiation process in the panel device. These features make $Cs_3Sb$ photocathodes suitable as flat emitters in panel device applications.

• Journal of the Korean Wood Science and Technology
• /
• v.26 no.1
• /
• pp.70-75
• /
• 1998

In this paper, the relationships between volumetric mixing ratio of rubber chip and physical and mechanical properties of wood/rubber composite panel was examined in order to investigate the mixture characteristics of wood and rubber chip. Because of the specific gravity of rubber differed from wood chip, physical properties of wood/rubber composite panel was shown very different values by mixing rate of chip element. Specific gravity in air-dry of composite panel was increased rapidly as volumetric percent of rubber chip was increased. Moisture content of composite panel was decreased as volumetric percent of rubber chip element was increased. This results was considered that wood weight is light and porosity material for moisture absorption. Compressive strength and modulus of rupture in bending test were decreased as volumetric percent of rubber chip increased. By mixing ratio control of chip elements, various wood/rubber composite panel can be applicable to every interior materials such as subfloor, playground, and exterior materials such as road blocks for recreational facilities in garden and forest and city parks.

• Advances in concrete construction
• /
• v.13 no.2
• /
• pp.153-162
• /
• 2022

Prefabricated exterior wall panel is the main non-load-bearing component of assembly building, which affects the comprehensive performance of thermal insulation and durability of the building. It is of great significance to develop new prefabricated exterior wall panel with durable and lightweight characteristics for the development of energy-saving and assembly building. In the prefabricated sandwich insulation hanging wall panel, the selection of material for the outer layer and the arrangement of the connector of the inner and outer wall layers affect the mechanical performance and durability of the wall panels. In this paper, high performance cement-based composites (HPFRC) are used in the outer layer of the new type wall panel. FRP bars are used as the interface connector. Through experiments and analysis, the influence of the arrangement of connectors on the mechanical behaviors of thin-walled composite wall panel and the panel with window openings under two working conditions are investigated. The failure modes and the role of connectors of thin-walled composite wallboard are analyzed. The influence of the thickness of the wall layer and their combination on the strain growth of the control section, the initial crack resistance, the ultimate bearing capacity and the deformation of the wall panels are analyzed. The research work provides a technical reference for the engineering design of the light-weight thin-walled and durable composite sandwich wall panel.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.9 no.4
• /
• pp.878-885
• /
• 2008

The FPDs(Flat Panel Displays) such as LCD(Liquid Crystal Display) and PDP(Plasma Display Panel) and OLED(Organic Light Emitting Diode), recently, have been substituted for CRT(Cathode Ray Tube) displays because they have a convex surface, small volume, light weight and lower electric power consumption. The productivity of FPDs is greatly dependent on the area of thin glass panel with 0.6 - 0.8mm thickness because FPDs are manufactured by cutting a large-scaled thin glass panel with patterns to the required product dimensions. So FPD's industries are trying to increase the area of thin glass panel. For example, the thin glass panel size of the 8th generation is 2,200mm in width, 2,600mm in length and 0.7mm in thickness. The air flows both in the thin glass panel and in the porous PE-plate surface were modeled and analyzed, from which a working condition was estimated. The thin glass panel on the porous PE-plate surface with self-lubricating characteristics was investigated and compared with that on the square duct floating bar surface with many holes of 1mm diameter when the thin glass panel contacts the floating bar surface due to malfunction of electric power supply.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1597-1600
• /
• 2005

Recently, the trends of TFT-LCD are large scale and thin thickness, so, the demands of Light Guide Panel(LGP) which is able to substitute for prism sheets are appeared. Functions of LGP obtaining polarization of light of the prism sheet as well as the incidence and reflection of light are demanded. This prismless type LGP to complete functions of the existing LGP and polarization at once must be supported by micro machining technology of LGP surface. In this research, we have used the STAMPER method for the mass product and In-Line process, and the optimized conditions are established by analyzing the cutting force and conditions according to the material and processing properties when the prismless type LGP mold is fabricated. Parameters of the cutting condition were the workpiece and cutting depth.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.7 no.6
• /
• pp.1343-1351
• /
• 2012

In this study, trends for five research areas of LED(Light Emitting Diode), OLED(Organic Light Emitting Diode), LCD(Liquid Crystal Display), PDP(Plasma Display Panel) and CRT(Cathode Ray Tube) are investigated using bibliometric analysis. The papers and patents citation data were extracted from Scopus and USPTO databases, respectively. We could figure out the research trends by the number of publications and citation information. We prospect the current interests and future trends by investigating the development process of the 5 research areas as function of time.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.8
• /
• pp.167-171
• /
• 2014

While the development of a portable plate panel display, thinning, high color reproduction, high brightness studies have been actively performed. LED, OLED is used as a light source. The research on quantum dot is much accomplished by the material of light source. Such quantum dot is the next generation semiconductor nano fluorescent substance because quantum dot has the high color reproduction and flexible display characteristic. In this study, we presented to method of using the quantum dot for implementation of the plate panel display. Quantum Dot (CdSe/ZnS), having a 100um thickness, is spread in PET barrier film. A Blue LED having a wavelength of 455nm as a light source irradiating light to the optical characteristic of the devices produced and evaluated. Also we presented the possibility for application with the color change film of the LCD.

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.9 s.186
• /
• pp.174-178
• /
• 2006

Pyramid shape of micro pattern is applied to the light guide panel (LGP) to enhance the uniformity of the brightness of the LCD. The micro pyramids are molded in intaglio on the surface of the LGP. The size of each pyramid is 5$\mu$m $\times$ 5$\mu$m on bottom and the height is about 3.5$\mu$m. The pyramids are distributed on the LGP surface randomly to be sparser where the light comes in and denser at the opposite side as a result of a simulation using lightools$^{TM}$ Based on this design, a silicon pattern master and a nickel stamper are fabricated by MEMS process and electro plating process. Intaglio micro pyramids are fabricated on the 6' of silicon wafer from the anisotropic etching using KOH and the process time, temperature of the KOH solution, etc are optimized to obtain precise shape of the pattern. A Wi stamper is fabricated from this pattern master by electro plating process and the embossed pyramid patterns turns out to be well defined on the stamper. Adopting this stamper to the mold base with two cavities, 1.8' and 3.6' LGPs are injection molded.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.11 no.2
• /
• pp.109-116
• /
• 2007

The purpose of this paper is to evaluate the fire resistant performances of load-bearing wall using both composite and steel stud panel infilled with light-weight formed mortar under axial loading according to KS F 2257(1999). The minimum requirement of 2 hours fire resistant rating is needed for the residential and commercial buildings under the fire regulation of Korea. From test results, it is found that two types of specimen composed of the hybrid stud and steel stud panel filled with light-weight formed mortar fited in with the requirement of 2 hours fire resisting rate for the load-bearing wall. In the conclusions, the specimen with hybrid stud shows predominating fire-resistant performance on the adiabatic effects rather than that of the steel stud specimen.