• Journal of the Korean Institute of Navigation
• /
• v.12 no.1
• /
• pp.27-43
• /
• 1988

The tedious work, connected to the altitude correction, the computation of altitudes and aximuths and the plotting of the position lines, has been a objection to celestial position fixing method. But using a computer , the severe objection will be practically overruled. The author had already studied on computerization of the sight reduction partially. This paper is to confirm reliability of coordinate of the moon and the navigational planet calculated by computer programming and to suggest a method of calculating ship's position fixed by two position lines.

• Journal of Ocean Engineering and Technology
• /
• v.10 no.1
• /
• pp.17-24
• /
• 1996

In the present paper nonlinear normal modes of a rotor system is studied. The methodology to obtain the nonlinear normal modes is based on center manifold reduction technique. It also provides a way of nonlinear coordinate transform from the physical cordinates to the modal coordinates and an idea of individual nonlinear modal dynamics. In order to apply the present method to a rotor dynamics a single mass rotor system on nonlinear elastic supports is employed and the nonlinear normal modes of the system are obtained.

• Textile Coloration and Finishing
• /
• v.21 no.3
• /
• pp.10-18
• /
• 2009

Dyeing process of the natural indigo powder onto ramie and silk fabrics was investigated by using glucose and calcium hydroxide as a reducing system. Effect of reduction and dyeing conditions such as temperature and time of reduction/dyeing, and concentrations of glucose and calcium hydroxide on the dyeing process were explored. Indigo powder was obtained by drying the conventional niram paste in an oven at $50^{\circ}C$. Color strength of the dyed fabrics was evaluated by K/S value measured at the wavelength of maximum absorption(${\lamda}$max). Munsell color coordinates(H V/C) were used to compare fabric colors of ramie and silk. Ramie fabric showed purple-blue color for all the temperature and time. On the contrary, silk fabric showed wide range of color including brown, brown-green, green at the different temperature. With the increase of K/S value, the coordinate of value(lightness) decreased for both of ramie and silk fabrics. The coordinate of hue(shade) changed drastically with the increase of K/S value for silk fabric, compared with that of ramie fabric which showed nearly constant value at the whole range of K/S value. Optimum concentrations of calcium hydroxide were for 6 g/L for ramie and 4 g/L for silk at $60^{\circ}C$ and 50 min. K/S value increased with the indigo concentration. Maximum K/S value was shown at $10{\sim}12$ g/L of glucose concentration. For both of ramie and silk fabrics, the colorfastness of washing and light was lower than that of rubbing. All the colorfastness values were improved with the increase of color strength.

• Journal of Astronomy and Space Sciences
• /
• v.32 no.3
• /
• pp.201-207
• /
• 2015

An algorithm to automatically extract coordinate and time information from optical observation data of geostationary orbit satellites (GEO satellites) or geosynchronous orbit satellites (GOS satellites) is developed. The optical wide-field patrol system is capable of automatic observation using a pre-arranged schedule. Therefore, if this type of automatic analysis algorithm is available, daily unmanned monitoring of GEO satellites can be possible. For data acquisition for development, the COMS1 satellite was observed with 1-s exposure time and 1-m interval. The images were grouped and processed in terms of "action", and each action was composed of six or nine successive images. First, a reference image with the best quality in one action was selected. Next, the rest of the images in the action were geometrically transformed to fit in the horizontal coordinate system (expressed in azimuthal angle and elevation) of the reference image. Then, these images were median-combined to retain only the possible non-moving GEO candidates. By reverting the coordinate transformation of the positions of these GEO satellite candidates, the final coordinates could be calculated.

• Journal of the Korean Society for Precision Engineering
• /
• v.33 no.4
• /
• pp.295-301
• /
• 2016

The out-of-squareness is one of the error sources that affect the positioning accuracy of machine tools and coordinate measuring machines. Laser interferometer is widely used to measure the position and angular errors, and can measure the squareness using an optical square. However, the squareness measurement using the laser interferometer is difficult, as compared to other errors due to complicated optics setup and Abbe's error occurrence. The effect of out-of-squareness mainly appears at the face-diagonal of the movable plane. The diagonal displacements are also affected by the position dependent geometric errors. In this study, the squareness estimation techniques via diagonal displacement measurement using the laser interferometer without an optical square were proposed. For accurate estimation and measurement time reduction, the errors selected from proposed discriminant were measured. Discrepancy between the proposed technique with the laser interferometer (with an optical square) result was $0.6{\mu}rad$.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.05a
• /
• pp.59-68
• /
• 2005

In this study, we establish a theory for dynamic behaviors of an automatic ball balancer, analyze its dynamic characteristics, and provide its design guide line. Equations of motion are derived by using the polar coordinate system instead of the rectangular coordinate system which was previously used in other researches. After non-dimensionalization of the equations, the perturbation method is applied to locate the equilibrium positions and to obtain the linearized equations of motion around the equilibrium positions. The Eigenvalue problem is used to verify the dynamic stability around the equilibrium positions. On the other hand, the time responses are computed from the nonlinear equations of motion by using a time integration method.

• Journal of Korean Institute of Industrial Engineers
• /
• v.41 no.3
• /
• pp.243-252
• /
• 2015

This paper considers a supply chain consisting of a manufacturer under the cap-and-trade emissions regulation and a permit supplier. We study joint production quantity and investment in reducing permit production cost decisions for centralized and decentralized supply chains. We formulate two supply chain contracts with aims to coordinate the decentralized supply chain; wholesale price contract and cost-sharing contract. Under the cost-sharing contract, the manufacturer shares a part of the investment in reducing permit production cost and then is allowed to purchase emission permit at a lower price. We analytically find that the proposed cost-sharing contract with reasonable parameters can coordinate the supply chain whereas the wholesale price contract is not desirable to achieve the system-wide profit. Numerical example is followed to support the analysis.

• Journal of the Ergonomics Society of Korea
• /
• v.9 no.2
• /
• pp.21-28
• /
• 1990

The robot motion control in the industrial robot is generally executed by the teach pendant. But, it requires much teaching time and workload to the operators. This study suggests the use of the robot motion control method by the computed keyboard in the industrial robot instead of the teach pendant. TES/CCS(Teaching Expert System/Cartesian Coordinate System) and TES/WCS(Teaching Expert System/World Coordinate System) that have been proposed to improve the robot motion control are applied for this concept. This study is intended to improve the robot motion control in TES/CCS. Parameter limitation problems in getting the motion data on position and posture of the robot in macro motion control are solved by proposed geometric algorithm. This result demonstrates reduction of the average teaching task time to the teaching position.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.16 no.6
• /
• pp.217-222
• /
• 2007

This paper describes a static gait generation process and a mechanical design process of leg mechanisms for quadruped robots. Actually robot walking is realized with the joint motion of leg mechanisms. In order to calculate the time-angle trajectories for each joint of leg mechanisms, we generate end-tip trajectories with time for each leg in the global inertial coordinate system intuitively, followed by coordinate transformations of the trajectories into the local coordinates system fixed in each leg, finally the angle-time trajectories of each joint of leg mechanisms are obtained with inverse kinematics. The stability of the gait generated in this paper was verified by a multi-body dynamic analysis using the commercial software $ADAMS^{(R)}$. Additionally the mechanical specifications such as gear reduction ratio, electrical specifications of motor and electrical power consumption during walking have been confirmed by the multi-body dynamic analysis. Finally we constructed a small quadruped robot and confirmed the gait.

• Journal of the Ergonomics Society of Korea
• /
• v.9 no.1
• /
• pp.21-27
• /
• 1990

Teaching Expert System/World Coordinate System(TES/WDS) was proposed to improve robot motion control. First, precise coordinate reading for getting the inherent data about position and posture of task objects was performed throgh the integrated image and fuzzy processing. Second, singularity and parameter limitation problems in getting the motion data about position and posture of robot in macro motion were solved by proposed geometric algorithm. Third, the unnecessary robot motion was also removed by the Robot Time and Motion (RTM) method and the Multi-Geometric Straight-Line Motion (MGSLM) method in micro motion. This results demonstrated reduction of the average teaching task time according to task order.