• Transactions on Electrical and Electronic Materials
• /
• v.15 no.1
• /
• pp.41-44
• /
• 2014

Emission properties of the organic light-emitting diodes were investigated with the use of a hole-injection layer of copper(II)-phthalocyanine (CuPc). The manufactured device structure is indium-tin-oxide (ITO) (180 nm)/CuPc (0~50 nm)/N,N'-Bis(3-methylphenyl)-N,N'-diphenylbenzidine (TPD) (40 nm)/tris-(8-hydroxyquinoline) aluminum (III) ($Alq_3$) (60 nm)/Al(100 nm). We investigated the luminescence properties of $Alq_3$ which is affected by the CuPc hole-injection layer. Also, we studied the influence of light-emission properties in the structure of an ITO/CuPc/TPD/$Alq_3$/Al device depending on the several thicknesses of CuPc (0~50 nm) layer. As a result, it was found that the hole injection occurs smoothly in the device with 20 nm thick CuPc layer, and the properties become significantly worse in the device with a CuPc layer thickness higher than 40 nm. We studied the topography and external quantum efficiency depending on the layer thickness of CuPc. Also, we analyzed the electroluminescent characteristics in the low and high-voltage range.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.439-440
• /
• 2007

To enhance the electron injection from the cathode of organic light-emitting diodes (OLEDs), We have studied characteristics of device that electron injection layer(EIL) is inserted between emissive layer and cathode. We fabricated bi-layer cathode $Li_2O$(x nm)/Al(100nm) and LiF(x nm)/Al(100nm) using LiF and $Li_2O$ as an electron injection layer. We analyzed the current efficiency, luminance efficiency, and external quantum efficiency of the device by varying the thickness of $Li_2O$ and LiF to be 0.5nm, 1nm, or 3nm. Using the EIL, we have obtained the efficiency of 7cd/A and the luminance of $20,000cd/m^2$. There is an improvement of efficiency by more than 3 times than the device without the $Li_2O$ layer.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.12
• /
• pp.57-64
• /
• 2017

Today, due to the environmental regulations regarding air pollution in the EU, the use of EPS (Styrofoam) as the cushioning material in the packaging industry is decreasing. In effect, air cushioning based cushioning materials are rapidly expanding into the market and replacing EPS, due to their excellent buffering ability and environmental friendliness. This is a new selective filling type air filling material manufacturing technology that affords improvements in the amount of raw materials required, its processing and its aesthetic appearance compared to the conventional air filling cushioning materials. In this study, a multi-stage air cell filling valve molding technology is developed based on selective filling technology, which allows packages to be selectively filled in various forms by applying valve forming structure technology. This multi-stage air cell filling valve molding technology is a technique in which a plurality of injection ports are formed by laminating three layers of films, viz. a first injection film, a valve film, and a second injection film having valve ends. In the conventional technology, a separate external air injection path for injecting air into a plurality of connected air bags is needed. However, in the proposed system, an external air injection path is formed inside the air bag, Due to the lack of need for an injection furnace, the raw material and process are reduced and air is injected and then discharged, while the air bag is reduced in length to 63 ~ 66% of its normal value. The outer surface of the outer air injection path is integrated inside by maintaining the original length of the cross section, while the unnecessary folded air is injected into the interior of the air bag, This smart air filling type cushioning material manufacturing technology constitutes a big improvement over the existing technologies.

• Proceedings of the KSR Conference
• /
• 2011.05a
• /
• pp.446-454
• /
• 2011

The noise of the subway has become a social issue and includes very complex reasons. The friction between rail and train wheel is the most important reason of the noise. In this study, we developed MFI(Multi Fluid Injection) System which sprays the mixed fluid(water, anticorrosive and lubricant) on the rail when the train is approaching to reduce the friction. To verify the system's effect, we measured the internal and external noise of the running train. The measured and analyzed results show that MFI system reduce the noise of the running subway.

• Journal of Biomedical Engineering Research
• /
• v.22 no.3
• /
• pp.303-309
• /
• 2001

It is well known that the electrical impedance of biological tissues is very sensitive to their temperature. In this paper, we have analyzed the effects of temperature change on the phase of magnetic resonance images obtained with external current injection. It has been found that the local phase in the current injected magnetic resonance image can be changed noticeably when local temperature change appears at a part of the tissue. At the experiments with a 0.3 Tesla MRI system, we observed the local phase changes at the phantom images when the phantom temperature was varied between 25 -45$^{\circ}C$. We think that the current injection MRI technique can be used for in-vivo monitoring of the temperature inside biiological tissues if the relation between the local temperature and phase can be quantified.

• Nuclear Engineering and Technology
• /
• v.41 no.8
• /
• pp.995-1004
• /
• 2009

The Advanced Power Reactor 1400 (APR1400) is an evolutionary advanced light water reactor (ALWR) based on the Optimized Power Reactor 1000 (OPR1000), which is in operation in Korea. The APR1400 incorporates a variety of engineering improvements and operational experience to enhance safety, economics, and reliability. The advanced design features and improvements of the APR1400 design include a pilot operated safety relief valve (POSRV), a four-train safety injection system with direct vessel injection (DVI), a fluidic device (FD) in the safety injection tank, an in-containment refueling water storage tank (IRWST), an external reactor vessel cooling system, and an integrated head assembly (IHA). Development of the APR1400 started in 1992 and continued for ten years. The APR1400 design received design certification from the Korean nuclear regulatory body in May of2002. Currently, two construction projects for the APR1400 are in progress in Korea.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2006.05a
• /
• pp.132-135
• /
• 2006

Injection molding is a flexible production technique for the manufacturing of polymer products, but introduces residual stresses. Residual stresses in a structural material or component are those stresses which exist in the object without other external loads. The layer removal and hole drilling method are used for the measurement of residual stress in injection molded polystyrene part. The hole drilling method is potentially more flexible for determining residual stress in complex geometries and can be used as an adoptable technique for the measurement of residual stress in polymeric materials. Results obtained by experiments agree with each other.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.25 no.6
• /
• pp.434-439
• /
• 2016

Optical fiber splice closure serves to protect connection parts from external environment. Moreover, it functions as a connection, junction, and distribution in diverse surroundings such as aerial, underground, duct, and pole. In this research, first, the optical fiber splice closure, its configuration, and the design problem were briefly investigated. Second, the design and application for in-line cable closure were studied to satisfy its construction and technical features. The injection molding conditions and optimal design were conducted to save time and cost during the manufacturing process. Third, methods to minimize loss via of optical fiber cable while strongly fixing optical fiber cable with optical cable holder to prevent fracture were researched, and tests such as perfect air tightness and mechanical and environmental performance were conducted.

• Proceedings of the KIEE Conference
• /
• 2005.07c
• /
• pp.2265-2267
• /
• 2005

We present detailed studies of externally applicable UHF PD sensors for a metal covered epoxy barrier with a small opening of epoxy injection-hole. The sensors were attached at the surface of injection hole of a metal covered epoxy barrier. 3-Dimensional electro magnetic simulations were performed to analyze electric-field distribution of the GIS and epoxy barrier with injection hole. Sensor structures were designed and analyzed using the 3-D EM simulator then fabricated for experimental verification. Sensor performance was measured in terms of spectral response and detected peak power. Real scale GIS and epoxy barriers were used to test and measure various aspect of performance of the sensors.

• Journal of the Korea Convergence Society
• /
• v.12 no.1
• /
• pp.127-132
• /
• 2021

The intravenous injection monitoring system used by medical institutions was developed to remotely provide patients with the amount of intravenous injected and the termination point of the injection. In order to measure the amount of intravenous injection input, the weight or flow rate of the level going out from the inside to outside of the intravenous injection can be observed with a measuring sensor. The criteria for devices that apply herein are accuracy and vigilance. In addition, it is compact and should be easy to use when installing intravenous injection on patients. In medical institutions, the accuracy of the measured values must be high, and economically inexpensive devices are required. In this study, low-cost small-weight-centered load cell sensors were applied, and algorithms were applied to reduce the artefact by external movement by converging with gyro sensors for accuracy of measurements. As a result, it was possible to reduce the error of measurement, thereby improving the accuracy of the intravenous injection monitoring measurement value.