• IE interfaces
• /
• v.5 no.1
• /
• pp.15-23
• /
• 1992

In a transfer line with mass production capability, calibration systems are included in the process as a separate dedicated station. However, this method is not appropriate in an unattended FMC with flexibility. As the FMC produces vesatile parts with small batch sizes, more flexible calibration systems are required. In this paper, a calibration/inspection system suitable for an unattended turning cell is introduced. The system has functions of dimensional calibration of parts by touch probes, tool wear compensation, and quality monitoring of parts. Furthermore, characteristics of errors in the system are identified and corresponding compensation methodology is suggested. An operation software is developed for efficient use of the system.

• Journal of Power System Engineering
• /
• v.6 no.1
• /
• pp.82-87
• /
• 2002

Not only ferrous but also non-ferrous materials such as aluminum, brass, plastic and woods need cutting operation in recent manufacturing industry. Over the past few years a considerable number of studies have been made on non-ferrous metal cutting. But more study is required to meet various engineering needs. The purpose of this paper is to preform an experiment on the influence of feed-rate adjustment and side rake angle in turning operations from non-ferrous metals. As a result, the surface roughness was reduced when a side-rake angle increases and feed-rate decreases in the case of the plastic, brass, aluminum, and paulownia. Therefore, this papers develop a new type bite that be used to adjust side-rake angle.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.12 no.3
• /
• pp.12-19
• /
• 1992

This paper shows that the identified and unidentified components of surface roughness in NC turning lathe which can not be analyzed in time domain such as $R_{max},\;R_a$ can be isolated in frequency domain by FFT analyzer. By interfacing FFT analyzer with stylus surface roughness instrument, surface roughness on change of working condition, especially tool feed, such as 0.1, 0.15, 0.2, 0.25, 0.3(mm/rev) can be analyzed in frequency domain as follows. 1. By frequency analysis of surface roughness profile, the basic wave length of surface roughness can be obtained to isolate the identified and unidentified components of surface roughness. 2. With increase of tool feed, the unidentified components of surface roughness increase. 3. Since $R_{max}$, which can be obtained by stylus surface roughness is proportion to the output voltage of FFT analyzer, FFT analyzer also can be used to measure surface roughness in time domain such $R_a,\;R_{max}$.

• Proceedings of the KSR Conference
• /
• 2004.06a
• /
• pp.501-506
• /
• 2004

This paper aims to suggest the feasibility of rapid operation scheme generated in preceding study, 'A study on development of operation planning for rapid service in urban railway(An introduction)' through application it to present subway lines in Seoul Metropolitan area. In case of line 3, without the Passing Track 'Turning train outstrip mode' is the best policy. In case of line 4, with the Passing Trank 'Passing track mode' may be the best way to realize the this scheme. Also, there is feasibility in the line 1, line 5, line 6, line 7 but there is no possibility it is applied to line 2 and line 8. In conclusion, this paper is intend to suggest the possibility of rapid operation in urban railway by presenting real operation scheme, time tables and amount of power usage and the number of composing trains and variety of demand,

• International journal of advanced smart convergence
• /
• v.9 no.2
• /
• pp.105-113
• /
• 2020

In this paper, we proposed a soft switched synchronous boost converter, which can perform discharging the battery, is proposed. The proposed converter has low switching loss even at high frequency operation due to its soft switching characteristics. The converter operates in synchronous mode to minimize conduction loss because of changing the rectified diode to MOSFET with a low on resistance. In this reason, the efficiency of the converter can be greatly improved in high frequency. In this paper, the battery discharger with a switching frequency of 100 kHz, has been designed. The designed converter also simulated to prove the converter's characteristics of synchronous operation as well as soft switching operation. The simulation shows that the proposed converter always meets the soft switching conditions of turning on and off switching in the zero voltage and zero current states. Therefore, simulation results have confirmed that the proposed battery discharge had soft switching characteristics. The simulation results have confirmed that the proposed battery discharger had soft switching and synchronous operation characteristics.

• Journal of Korean Biological Nursing Science
• /
• v.11 no.1
• /
• pp.92-98
• /
• 2009

Purpose: This study was aimed to investigate the colony counts by different disinfecting processes and duration of the operation for humidifiers in an intensive care unit (ICU) in Busan. Method: The four steps of disinfecting process were taken with four different humidifiers according to the use of disinfectant (1:100 $Deconex^{(R)}$ 50FF/nothing) and refilling water (tap water/distilled water). First, the colony counts using water sample from wick was conducted at 0 hr, 24 hr, and 48 hr respectively after turning on the humidifiers. Next, the colony counts using waterdrop from the outlet was done at 0 hr, 24 hr, 48 hr, and 72 hr respectively after turning on the humidifiers. Result: No colony was counted after disinfecting with 1:100 $Deconex^{(R)}$ 50FF until 72 hr after turning on the humidifiers. However, without disinfecting with $Deconex^{(R)}$ 50FF, the colony count was increased in the humidifiers from 24 hr after turning on the humidifiers. The result was the same regardless of the refilling water. Conclusion: According to the results, the study found that disinfection of humidifiers in the ICUs with 1:100 $Deconex^{(R)}$ 50FF every 72 hr is effective to remove general bacteria.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.4
• /
• pp.2430-2435
• /
• 2015

In order to achieve high flexibility in manufacture, analysis of chip's shape is one of the most important problems. This paper describes the change of machining characteristics in workpiece materials depending on turning clearance angle. The experiments start from choosing three workpiece materials that are SM45C(machine structural carbon steel), STS303(stainless steel), SCM415 (chrome-molybdenum steel). Then, the experiments show specifically how features of selected materials changed when they were processed with diverse machining depths and with feed rate starting from fixed rotational speed. Especially, the experiments were also analyzed in chip's shape and wear of insert tip. In conclusion, these experiments show that chip's shape was changed by quality of the materials, depth of cut, and conveying speed. When machining feedrate and machining depth were 0.10mm/rev and 0.3mm respectively, workpiece materials showed the best shapes, not categorizing quality of the materials and machining characteristics.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.56 no.2
• /
• pp.172-182
• /
• 2020

In order to offer specific information needed to assist in operation of a ship with same type rudder through evaluating the maneuverability of training ship A-Ra with flapped rudder, sea trials based full scale for turning test, zig-zag test with rudder angle 10° and 20°, and spiral test at service condition were carried out on starboard and port sides around Jeju Island according to the standards of maneuverability of IMO. As a result, the angular velocity of port turn was higher than that of starboard turn. Therefore, the size of turning circle was longer on the starboard side. In addition, variation of the transfer due to various factors was more stable than those of the others. In the Z-test results, the mean of 1st and 2nd overshoot angles were 9.8°, 6.3° and 15.3°, 9.2° respectively when the port and starboard was 10°; the 1st overshoot angle were 18°, 13.7° when using 20°. Her maneuverability index T' and K' can be easily determined by using a computer with the data obtained from Z-test where K' and T' are dimensionless constants representing turning ability and responsiveness to the helm, respectively. In the Z-test under flap rudder angle 10°, the obtained K' value covered the range of 2.37-2.87 and T' was 1.74-3.45. Under the flap rudder angle 20°, K' and T' value showed 1.43-1.63, 1.0-1.73, respectively. In the spiral test, the loop width was unstable at +0.3° and -0.5°-0.9° around the midship of flap rudder. As a result, course stability was comparatively good. From the sea trial results, training ship ARA met the present criterion in the standards of maneuverability of IMO.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.63 no.4
• /
• pp.219-225
• /
• 2014

The purpose of this paper is to control of the low-speed, high-precision PMSM 2-axes pitch/turning. In this paper, apply the PAM-PWM inverter for it. However, The PAM-PWM inverter, control algorithms and hardware is complex. But it is possible to improve the performance in the low-speed operation can reduce the effect of the PWM ripple and Dead Time of inverter by applying suitable DC-bus voltage control. The direct driver PMSM(Permanent Magnet Synchronous Motor) configured to vector control part, PAM control part and the other controller. The vector control part includes PI current, speed control, additional space vector modulation. PAM control part has to have PI voltage controller and P current controller for DC-bus voltage control. Besides, the motor position estimator, the speed estimator and the counter electromotive force and Dead Time Compensation are added. With this arrangement, PMSM was driven with a low pole pitch/turning by performing the current control to the current command or torque command is the paper. As a result, it was possible to minimize the disturbance component that appears in the drive in proportion to the DC voltage magnitude. The use of a hydraulic drive method for a two-axis bubble column is a typical tank. When using the PWM PAM inverter driver is in the turret can be driven by high-precision, low vibration, low noise compared to the hydraulic drive may contribute to the computerization of the turret.

• Structural Engineering and Mechanics
• /
• v.86 no.1
• /
• pp.119-137
• /
• 2023

The purpose of this research is to assess the performance of CBN and ceramic tools during the dry turning of gray cast iron EN GJL-350. During the turning operation, the variable machining parameters are cutting speed, feed rate, depth of cut and type of the cutting material. This contribution consists of two sections, the first one deals with the performance evaluation of four materials in terms of evolution of flank wear, surface roughness (2D and 3D) and cutting forces. The focus of the second section is on statistical analysis, followed by modeling and optimization. The experiments are conducted according to the Taguchi design L₃₂ and based on ANOVA approach to quantify the impact of input factors on the output parameters, namely, the surface roughness (Ra), the cutting force (Fz), the cutting power (Pc), specific cutting energy (Ecs). The RSM method was used to create prediction models of several technical factors (Ra, Fz, Pc, Ecs and MRR). Subsequently, the desirability function approach was used to achieve a multi-objective optimization that encompasses the output parameters simultaneously. The aim is to obtain optimal cutting regimes, following several cases of optimization often encountered in industry. The results found show that the CBN tool is the most efficient cutting material compared to the three ceramics. The optimal combination for the first case where the importance is the same for the different outputs is Vc=660 m/min, f=0.116 mm/rev, ap=0.232 mm and the material CBN. The optimization results have been verified by carrying out confirmation tests.