• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.43 no.5
• /
• pp.405-412
• /
• 2015

This paper represents a filter design to estimate the airspeed of a spin-stabilized, trajectory-correctible artillery ammunition. Due to the limited power and space in operational point of view, the airspeed sensor is not installed, and thus the airspeed need to be estimated using limited sensor measurements. The only IMU measurements(three-axis specific forces and angular rates) are used in this application. The extended Kalman filter algorithm is applied since a linear filter can not cover the its wide operational range in airspeed and altitude. In the implementation of the EKF, the state and measurement equations are transformed into the no-roll frame for simple form of Jacobian matrix. The simulation study is conducted to evaluate the performance of the filter under various environment conditions of sensor noise and wind turbulence. In addition, the effect of the choice in filter design parameters, i.e. process error covariance matrices is analyzed on the performance of the estimation of airspeed and angular rates.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.3
• /
• pp.177-184
• /
• 2014

In chemical vapor deposition(CVD) tungsten silicide(WSix) dual poly gate(DPG) scheme, we observed the fluorine effects on gate oxide using the electrical and physical measurements. It is found that in fluorine-rich WSix NMOS transistors, the gate thickness decreases as gate length is reduced, and it intensifies the roll-off properties of transistor. This is because the fluorine diffuses laterally from WSix to the gate sidewall oxide in addition to its vertical diffusion to the gate oxide during gate re-oxidation process. When the channel length is very small, the gate oxide thickness is further reduced due to a relative increase of the lateral diffusion than the vertical diffusion. In PMOS transistors, it is observed that boron of background dopoing in $p^+$ poly retards fluorine diffusion into the gate oxide. Thus, it is suppressed the fluorine effects on gate oxide thickness with the channel length dependency.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.48 no.11
• /
• pp.927-933
• /
• 2020

This paper presents a fuel quantity measurement system (FQMS) for an aircraft supplementary fuel tank considering the change of aircraft attitude. The developed FQMS consists of fuel sensors, a signal process unit, an indicator and a software to estimate the fuel quantity from the sensor data. To replicate the change of the roll and pitch attitude on the ground, the test simulator is developed in this work. Using the test simulator, the sensor data at various fuel quantities, roll and pitch angles are automatically measured to build a training data set. The data-driven software to estimate the fuel quantity is then developed using a trilinear interpolation method with the training data set. The developed FQMS is verified by investigating the fuel estimation error of the test data set that we know the true values. Through the test, it is confirmed that the error of the developed FQMS system satisfies the criteria of TSO-C55 document.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.16 no.2
• /
• pp.201-206
• /
• 2016

Aircraft have a cross axis of the three each other for maintenance of aircraft position. It is called roll axis, pitch axis and yaw axis. Attitude reference system is a sensor for detecting a change of the three axis. In this paper, mobile robot platform install part of Pan-tilt and HMD attitude reference system, because of we use control camera. The acceleration sensor is very weak a lot of noise to vibration, also problem with data from process of mapping to the data problems to arise. However to solve this problem, we removed the average filter and Cosine Interpolation for Pan-tilt. Using capacity evaluation for outdoor environment for we are proposing. Mobile robot has HMD and equipped Pan-tilt. We control mobile robot camera. In this experiment result is little bit delay happening, however Pan-tilt camera is relatively stable control checking. Also, we will checking any terrain and slopes is no problem for mobile robot driving skills.

• Proceedings of the KSME Conference
• /
• 2007.05b
• /
• pp.2279-2284
• /
• 2007

This study is intended to analyze the effect of thin ink-film thickness around rotating printing roll on the printing quality in the gravure printing process which is used for making electronics circuit like a RFID tag with a conductive ink. The present work numerically estimates the film thickness around rotating roller partially immersed in ink, for which the volume of fluid (VOF) method was adopted to figure out the film formation process around rotating roller. Parameter studies were performed to compare the effect of ink viscosity, surface tension, roller rotating speed, immersed angle on the film thickness. The result indicates that the film thickness has a strong dependency on the fluid viscosity, while the surface tension has negligible effect.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2004.08a
• /
• pp.359-367
• /
• 2004

In this research on-line model for the prediction of the effective strain distribution in strip on finishing mill process is presented. To describe the effective strain distribution in strip, three guide points and a distribution fitting variable are used. On-line models to get these points and fitting variable non-dimensionalization method and least square method were used with FEM simulation results. The model is developed using strip only FEM simulation as reference sets and compared with roll coupled FEM simulation results as perturbed sets. The on-line model to describe effective strain distribution shows good agreement with coupled FEM analysis results.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.31 no.12
• /
• pp.1017-1023
• /
• 2007

This study is intended to analyze the effect of thin ink-film thickness around rotating printing roll on the printing quality in the gravure printing process which is used for making electronics circuit like a RFID tag with a conductive ink. The present work numerically estimates the film thickness around rotating roller partially immersed in ink for which the volume of fluid (VOF) method was adopted to figure out the film formation process around rotating roller. Parameter studies were performed to compare the effect of ink properties (viscosity, surface tension), operating condition (roller rotating speed, initial immersed angle) on the film thickness. The result indicates that the film thickness has a strong dependency on the rotating speed, while the surface tension has negligible effect.

• Journal of Adhesion and Interface
• /
• v.19 no.4
• /
• pp.154-162
• /
• 2018

Plasma treatment and corona treatment have been used for surface modification of polydimethylsiloxane (PDMS) film by activating its surface with the -OH group. Adhesion promoter or coupling agent was also used to improve adhesion of PDMS film with various materials. However, obtained hydrophilicity onto the surface of PDMS films with those processes was transient and vulnerable. In this study, a new alkoxysilane-functionalized acrylic polymer precursor was first synthesized by copolymerization process, and then was reacted with HO-terminated PDMS through condensation reaction to prepare a new surface modifier for PDMS film. The structure and molecular weight of the prepared surface modifier were confirmed by 1H-NMR and GPC measurement. Surface properties of surface modifier-coated PDMS films were also investigated by using XPS, ATR and WCA analysis. The adhesion between the PDMS film and the surface modifier was tested using cross-cut test.

• Journal of the Korean Society for Precision Engineering
• /
• v.31 no.12
• /
• pp.1161-1170
• /
• 2014

Delta sash is an important part of automobile door, which has the functions of supporting and guiding seesaw of car's window, preventing dust and air from outside. In previous manufacturing process, each part of the delta sash was independently formed by tandem processes, and rubber is bonded to steel by poisonous glue. So, the previous processes, including roll forming process and toxic gases, had low production rate and high failure rate. In this study, progressive process design of the delta sash was proposed in order to increase productivity and high utilization of the materials. And instead of the poisonous glue used for adhesion of rubber in the previous tandem process, embossing and piercing processes were designed in the new guide to help the rubber to adhere well to steel. And the optimal piercing distance was designed to ensure structural safety, and prototypes were manufactured for verifying reliability of the processes.

• Korean Journal of Materials Research
• /
• v.13 no.11
• /
• pp.721-724
• /
• 2003

A Fe-Si-B-Ni amorphous alloy manufactured by one roll melt-spinning method showed the crystallization temperature difference of a maximum $10^{\circ}C$ according to each lot. This temperature difference had a considerable influence on the annealing process to be conducted for obtaining the proper inductance of the alloy. The proper annealing temperature of the alloy was $480^{\circ}C$ and the annealing time increased as the crystallization temperature increased. The activation energy measured by Kissinger method increased as the crystallization temperature increased. Therefore, the annealing process must be adjusted by the crystallization temperature difference of the amorphous alloy.