• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2008.06a
• /
• pp.351-352
• /
• 2008

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2004.10a
• /
• pp.267-270
• /
• 2004

In Micro injection process, it is needed to the technique of making micro die, Rapid Thermal Pressing (RTP) and other techniques. Those techniques are independent. But the mutual connected system of techniques is needed. The target of this paper is the design of micro mold and the development of the entire micro injection techniques for functional polymer.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.24 no.8
• /
• pp.1030-1036
• /
• 2020

The DSRC method currently in use has a limitation in providing various ITS services by short-distance wireless communication. Therefore, the WAVE/DSRC hybrid wireless platform, which was developed by applying WAVE technology in-house, improved the data transmission speed and greatly expanded the transmission range. The summary H/W and S/W technologies are summarized in the text. In this paper, various services such as BSM, SPAT, MAP, and road video information related to ITS services have been implemented, and various tests are conducted based on scenarios considering the environment in the actual field by utilizing the previously developed WAVE/DSRC composite wireless platform. Through this emulation process in the real field, we were able to verify the excellence of the WAVE/DSRC composite wireless platform once again and predict the usefulness and potential of development services in real field operations.

• International Journal of Aeronautical and Space Sciences
• /
• v.1 no.1
• /
• pp.48-61
• /
• 2000

Korea Aerospace Research Institute (KARI) have gained experience with Helicopter Vibration Health Monitoring (VHM) System technology with the help of UK GKN-WHL. GKN-WHL have had many years of experience with the research and development of vibration analysis techniques to improve the health monitoring of helicopter transmissions. This activity was targeted at transmission rig testing at first, but the techniques have been progressively developed where they are now used as a part of integrated Health and Usage Monitoring (HUM) systems on many types of in-service and new helicopters. The technique development process has been considerably aided by an ever expanding database of transmission monitoring experience from both the rig testing and aircraft operations. This experience covers a wide range of failure types from naturally occurring faults to crack propagation studies and covering a wide range of transmission configurations. Primarily based on accelerometer signals GKN-WHL's vibration analysis methods have also been applied to a variety of other sensor types. The transition from an experimental environment to operational VHM systems has been a lengthy process, there being a need to demonstrate technique reliability as well as effectiveness to both regulatory (Airworthiness Authority) and commercial organizations. Another important feature of this process has been the development of close relationships with a number of VHM system hardware and software suppliers. Such an experienced GKN-WHL provides various raw vibration data which was acquired from transmission ground test rig and allow KARI to develop it's own analysis program. KARI made a program and then analyzed the data to coma pre with the results of GKN-WHL. The KARI's results both time domain signals and statistical values show comparable to GKN's.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.15 no.6
• /
• pp.147-154
• /
• 2015

Recently agile development process became increasing effectiveness, quality, attention to experts in customer satisfaction, as evidenced in this methodology when selecting projects promoting productive efficiency. With regard to contemporary needs and user requirements on the methodology selected to meet this paper is the product based Cross functional team suggested methodology Feature Team model to solve problems of this model, and organizing the Cross functional team, this team but this outcome (product) basis, were examined for the model that points to progress the development across multiple product as a functional unit, value-driven agile project through the Skills-based model and proposed a difference. And it examined the Agile Maturity metrics. PRINCE2 Agile Health-check entries future development direction of Agile techniques is a requirement of the project outset has studied the subject objective evaluation by the assumption that they can be changed at any time, not fixed this way and for the project team through research The proposed.

• Transactions of Materials Processing
• /
• v.18 no.7
• /
• pp.538-543
• /
• 2009

The cowl cross bar of an automobile is a frame component that is installed inside the cockpit module to provide a guide surface, to which functional components for electricity and air condition are attached. In the recent years, the geometries of cowl cross bars are getting more complex in order to meet the demands of a wide variety of embedded functional components and the reduced weight of frame parts with enhanced mechanical and noise/vibration characteristics. There for, welding processes between tubes with different diameters are widely conducted while the welded parts are experiencing various problems such as undermined appearance, low production efficiency and poor mechanical characteristics. Therefore, this paper seeks to develop an one-piece forming process which eliminate welding process for the cowl cross bar by applying the tube drawing process. However, it was predicted that a conventional tube drawing can not be applied directly to the current part since the area reduction ratio of the drawing process reaches 51.7% which exceeds the general limiting value. Therefore, in this study, a combined drawing process which adds a compressive force to a tensile force of the conventional drawing process was proposed and 2-stage drawing process was designed by using CAE analyses. In addition, drawing tryouts were carried out by using the manufactured combined drawing machine in order to verify the designed process.

• Transactions of Materials Processing
• /
• v.30 no.5
• /
• pp.242-246
• /
• 2021

Aluminum alloy sheet is being applied to automobiles continuously for the purpose of reducing car body weight. However, due to low formability, there's a limit to application of products with a deep forming depth such as door inner parts. Therefore, the difficult-to-form parts are mainly segmented formed then joined together, which is also disadvantageous as it increases the cost of manufacturing. This study proposes a hybrid cold-hot stamping method for the 1-piece door inner part to reduce cost. To design the stamping process, numerical simulation method is established by using the temperature-dependent mechanical properties of AA6016. The formability according to the hybrid cold-hot stamping method is evaluated using numerical analysis. The suitability of the proposed stamping method is then verified through the stamping tryout.

• Progress in Superconductivity and Cryogenics
• /
• v.13 no.1
• /
• pp.1-5
• /
• 2011

[ $CeO_2$ ]has been widely used for single buffer layer of coated conductor because of superior chemical and structural compatibility with $ReBa_2Cu_3O_{7-{\delta}}$(Re=Y, Nd, Sm, Gd, Dy, Ho, etc.). But, the surface of $CeO_2$ layer showed cracks because of the large difference in thermal expansion coefficient between metal substrate and deposited $CeO_2$ layer, when thickness of $CeO_2$ layer exceeds 100 nm on the biaxially textured Ni-3%W substrate. The deposition rate has been limited to be less than 6 $\AA$/sec in order to get a good epitaxy. In this research, we deposited $CeO_2$ single buffer layers on biaxially textured Ni-3%W substrate with 2-step process such as thin nucleation layer(>10 nm) with low deposition rate(3 $\AA$/sec) and thick homo epitaxial layer(>240 nm) with high deposition rate(30 $\AA$/sec). Effect of deposition temperature on degree of texture development was tested. Thick homo epitaxial $CeO_2$ layer with good texture without crack was obtained at $600^{\circ}C$, which has ${\Delta}{\phi}$ value of $6.2^{\circ}$, ${\Delta}{\omega}$ value of $4.3^{\circ}$ and average surface roughness(Ra) of 7.2 nm within $10{\mu}m{\times}10{\mu}m$ area. This result shows the possibility of preparing advanced Ni substrate with simplified architecture of single $CeO_2$ layer for low cost coated conductor.

• Current Industrial and Technological Trends in Aerospace
• /
• v.8 no.2
• /
• pp.86-97
• /
• 2010

This paper treats with the history and current trends in the developments of liquid-propellant rocket engine in Russia and Ukraine which are among world leaders in the technology of liquid rocket engine(LRE). In 1960s formerly the Soviet Union accepted the closed cycle engine for increasing the pressure in the combustion chamber and specific impulse to the maximum. However, since financially difficult times after 1990, they have decreased the cost for the development of new rocket engines. It was achieved by using existing units for new developed engines and minimizing the total number of engines and tests through the reasonable planning in the process for the experimental improvement of LRE. In addition, nowadays international cooperation in supplying LRE for commercial rocket and development of next generation LRE, such as 3 components engines and mathane engines, are proceeding.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.405-408
• /
• 2004

The sheet parts are formed with dies conventionally. But this conventional forming process is not suited to small volume and varied production for the reason of high cost. For the solution of this problem, a new forming process, which is called CNC incremental sheet forming, is being introduced. This process can form sheet parts without die, and is very well suited to small volume and varied production in space flight and automobile. In this paper, dieless CNC forming system based on a machining center is developed. A special device to grasp and pull the blank sheet built in the machining center and tool path generation S/W from STL file of 3-D model are developed. Several sheet parts are incrementally formed to verify the effectiveness of the developed system.