• Journal of the Korean Society for Precision Engineering
• /
• v.20 no.12
• /
• pp.105-114
• /
• 2003

In this study, a dicing machine with vision system was built and an algorithm for automatic alignment was developed for dual camera system. The system had a macro and a micro inspection tool. The algorithm was formulated from geometric relations. When a wafer was put on the cutting stage within certain range, it was inspected by vision system and compared with a standard pattern. The difference between the patterns was analyzed and evaluated. Then, the stage was moved by x, y, $\theta$ axes to compensate these differences. The amount of compensation was calculated from the result of the vision inspection through the automatic alignment algorithm. The stage was moved to the compensated position and was inspected by vision for checking its result again. Accuracy and validity of the algorithm was discussed from these data.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.22 no.1
• /
• pp.16-27
• /
• 2018

A basic numerical analysis was performed to confirm the possibility of combining a dual bell nozzle and an Expansion-Deflection(E-D) nozzle. The dual bell nozzle was designed based on the first-stage nozzle of the Korean Space Launch Vehicle that is being developed, and the E-D nozzle concept was applied to the dual bell nozzle. The inlet condition was analyzed by applying eight types of frozen flow analysis, and k-${\omega}$ SST was selected as the turbulence model. The number of optimal grids was obtained as 240,000 through the grid sensitivity analysis. As a result, it was confirmed that the transition altitude increased owing to over-expansion when the E-D nozzle concept was applied to the dual bell nozzle, and the specific impulse gain was obtained at high altitudes compared with the KSLV-II first-stage engine.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.16 no.6
• /
• pp.465-471
• /
• 2023

This paper proposes a comparator structure that improves the noise and output delay of a single-slope ADC(SS-ADC) used in CMOS Image Sensor (CIS). To improve the noise and delay characteristics of the output, a comparator structure using the miller effect is designed by inserting a capacitor between the output node of the first stage and the output node of the second stage of the comparator. The proposed comparator structure improves the noise, delay of the output, and layout area by using a small capacitor. The CDS counter used in the single slop ADC is designed using a T-filp flop and bitwise inversion circuit, which improves power consumption and speed. The single-slope ADC also performs dual CDS, which combines analog correlated double sampling (CDS) and digital CDS. By performing dual CDS, image quality is improved by reducing fixed pattern noise (FPN), reset noise, and ADC error. The single-slope ADC with the proposed comparator structure is designed in a 0.18-㎛ CMOS process.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.17 no.2
• /
• pp.142-149
• /
• 2012

The independently regulated dual-output LLC resonant converter using only one power stage and one control IC is proposed in this paper. The conventional dual-output LLC resonant converter requires the extra non-isolated DC/DC converter to obtain the tightly regulated slave output voltage, which results in the low power conversion efficiency and high production costs. On the other hand, since the proposed converter controls the master and slave output voltages by pulse width modulation(PWM) and pulse frequency modulation(PFM), it can achieve tightly regulated dual output voltages without the additional non-isolated DC/DC converter. Therefore, it features a high efficiency and low cost. To confirm the validity of the proposed converter, theoretical analysis and experimental results from a 40W LED driver prototype are presented.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.13 no.12
• /
• pp.965-971
• /
• 2003

To reach high areal density, less track pitch is expected and more servo bandwidth is required. One approach to overcoming the problem is by using dual stage servo system. For this system. we have suggested new milliactuator based on the shear mode of piezoelectric elements to drive the head suspension assembly. In this paper, we introduce milliactuator and controller design method, PQ method. PQ method reduces the controller design problem for DISO (dual-input/single-output) systems to two standard controller design problems for SISO ( single-input/single-output) problems. The first part of PQ method directly addresses the issue of actuator output contribution, and the second part allows the use of traditional loop shaping to achieve the overall system performance. This paper shows how to employ the PQ method to meet aggressive close-loop performance specifications for a disk drive system with a VCM and piezoelectric milliactuator.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.23 no.2
• /
• pp.503-524
• /
• 1996

A series of 31 patients with primary oral squamous cell carcinoma (SCC) who were treated at Chonbuk National University Hospital during the years 1991-1995, were evaluated by dual parameter analysis in flow cytometric DNA measurement, Bryne's malignancy grading system, and the TNM classification. The aims of the present study were to discover that previously undetected aneuploid clones could be detected by dual parameter analysis and to determine the prognostic value of the above parameters. 1. Using dual parameter analysis of cytokeratin and DNA on disintegrated paraffin-embedded samples, aneuploid clones which were undetected by regular single parameter DNA analysis could be found among the cytokeratin-selected cells. DNA aneuploidy from paraffin-embedded samples were 15 cases compared with 10 cases using conventional DNA analysis. 2. The portion of aneuploid tumors showed slightly higher clinical stage and tumor size than the portion of diploid tumors, but the difference was not significant. The portion of DNA aneuploid tumors showed significantly higher mean mitosis and total malignancy scores than the portion of DNA diploid tumors. 3. The majority of the patients presented with clinical stage III and IV lesions showed significantly higher mean total malignancy score as compared to those with clinical stage I and II. 4. Histopathologic mean total malignancy score of the 31 cases was 12.7. Among the histologic parameters, mean mitosis score was correlated to the status of DNA ploidy and total malignancy score were correlated to the DNA ploidy and clinical staging.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.15 no.11 s.104
• /
• pp.1276-1286
• /
• 2005

In this paper, the dual stage interaction between the coarse actuator and the fine actuator of an optical disk drive is studied, and the new control method to enhance the track pull-in performance using fine actuator control is proposed. First, the dynamic analysis for the dual stage and the experiments to find the each actuator dynamics are performed. From the experiments, some physical parameters of the actuators were derived, then, some simulations are performed to find the interaction effect of the fine actuator during seek motion. Second, the center servo which suppresses the vibration of fine actuator during seek motion is designed and evaluated. And the fine actuator control to reduce the relative velocity between the target track and beam spot is proposed. From simulations, we show that fine actuator control which has same frequency and same phase of the disturbance is effective to reduce the relative velocity, and this result leads to track pull-in enhancement. Hence, the proposed control method is good approach to improve the track pull-in performance. Finally, the realization of the proposed method and some comments of it are briefly discussed.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.34 no.2
• /
• pp.36-47
• /
• 2006

The process of dual spin turn maneuver is introduced for attitude acquisition or recovery from flat spin state of a satellite. The physical principle of momentum transfer during dual spin turn is explained clearly. The case studies of special dual spin turn, in addition to the conventional dual spin turn, that are known as an acceptable cases, are performed to investigate the principle of dual spin turn and to provide a physical insight as well as the solution of dual spin turn. This study is done based on case-study simulation, which includes two-state control scheme composed of open-loop maneuver and energy dissipation device. Furthermore, we investigate the stability for the verification of all control cases after implementing two-stage control. We also provide the simulation scenario of flat spin recovery using dual spin turn method as an example.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.05a
• /
• pp.413-414
• /
• 2010

• Journal of Yeungnam Medical Science
• /
• v.10 no.2
• /
• pp.369-379
• /
• 1993

The bone mineral density(BMD) of the lumbar spine (L2-L4) was measured by using dual energy x-ray absorptiometry(Norland XR26 DEXA) in 80 children aged between 2months and 15years (group 1 : 2month-1years, group 2 : 1year-5years, group 3 : 6years-10years, group 4 : 11years-15years). The correlation coefficient of BMD with age, body weight, height and Tanner stage were 0.696, 0.693, 0.717 and 0.636 respectively. There were significant difference in BMD($g/cm^2$) between group 1(BMD : $0.335{\pm}0.175$) and group 2(BMD : $0.627{\pm}0.200$). and group 3(BMD : $0.714{\pm}0.189$) and group 4(BMD : $0.873{\pm}0.163$)(P<0.05). There was no significant difference of BMD between boys and girls(P<0.05). BMD also increased significantly with development of Tanner stages(Tanner stage 1 : $0.547{\pm}0.234$, Tanner stage 2 : $0.783{\pm}0.136$, Tanner stage 3 : $0.998{\pm}0.080$ )(P<0.05). These data indicate that the BMD was correlated with age, body weight, height and Tanner stage significantly and BMD increased significantly during growth spurt occured in 1 to 4years of age and puberty.