• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.38 no.4
• /
• pp.33-38
• /
• 2001

Readout signal of high density DVD-RAM disk output was simulated to analyze the effect of crosserase and crosstalk to the readout signal which is one of the main difficulties to realize high density DVD-RAM system having single side recording density of 4.7 G13 and 15 G13 media. Laser beam intensity impinged on the disk was approximated as Gaussian and recorded marks were assumed elliptical and the readout signal was calculated as a two dimensional convolution of laser beam pattern and recored mark pattern. From the readout signal obtained by varying crosserase ratio, carrier levels with period of 3T to 11 T were calculated and compared. Jitter due to crosserase and crosstalk was calculated and compared using 1,000 random marks having 3T to 11T period. The results showed that the jitter due to crosserase turned out to be smaller than the jitter due to crosstalk.

• Proceedings of the KSME Conference
• /
• 2001.06d
• /
• pp.585-588
• /
• 2001

Particle contamination on the data storage disks has been a serious problem for magnetic hard disk drive manufacturers. For high storage optical disks, such as DVD-ROM/RAM or NFR (near field recording) system, particle-induced damages can be also detected because only a few micrometer particles can prevent read/write signal from optical lens. The increasing areal density and smaller bit size accelerates particle induced damages on the optical disk. One of the methods to prevent particle contamination on the optical disk surface is to handle the disk enclosed in a cartridge like a modern DVD-RAM disk. However, even for a perfectly sealed disk drive, particles are found inside the drive. The other method is to improve disk surface characteristics. Particle contamination on the surface can be reduced by proper selection of disk coating materials. [n this paper, particle detachment ratios for CD (compact disk), DVD (digital versatile disk), HD (magnetic hard disk), HD with Jut lubricant, and aluminosilicate substrate HD were investigated. Surface roughness and surface energy of the test disks were compared with the particle detachment ratios. Proper substrate and lubricant characteristics to reduce particle contamination on the disk surface were found.

• Proceedings of the KIEE Conference
• /
• 1999.07b
• /
• pp.1009-1012
• /
• 1999

Recently, there is a strong need of DVD (Digital Versatile Disk) system of high density. high speed, and high accuracy System performances mostly depend on not only optical system, but also servo technology to drive it. Therefore, we investigate main technology concerned with optical pick-up unit based on 4.7GB DVD-RAM and analyzes technology of optical and servo systems that are required for high density high speed and high accuracy from the viewpoint of control. And then, we design a linear controller based on specification of 4.7GB DVD-RAM that is commercially available now. We analyze the dynamic characteristics of optical system that is coupled with control system and verify effect on performance indices of servo due to Parameter variation of pick-up by simulation. Finally, we will propose controller design specifications and provide direction of technical development for servo system and problems coupled with high capacity for 15GB level in the future.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.7 no.4
• /
• pp.247-253
• /
• 2007

In this paper, a high throughput multiple transform architecture for H.264 Fidelity Range Extensions (FRExt) is proposed. New techniques are adopted which (1) regularize the $8{\times}8$ integer forward and inverse DCT transform matrices, (2) divide them into four $4{\times}4$ sub-matrices so that simple fast butterfly algorithm can be used, (3) because of the similarity of the sub-matrices, mixed butterflies are proposed that all the sub-matrices of $8{\times}8$ and matrices of $4{\times}4$ forward DCT (FDCT), inverse DCT (IDCT) and Hadamard transform can be merged together. Based on these techniques, a hardware architecture is realized which can achieve throughput of 1.488Gpixel/s when processing either $4{\times}4\;or\;8{\times}8$ transform. With such high throughput, the design can satisfy the critical requirement of the real-time multi-transform processing of High Definition (HD) applications such as High Definition DVD (HD-DVD) ($1920{\times}1080@60Hz$) in H.264/AVC FRExt. This work has been synthesized using Rohm 0.18um library. The design can work on a frequency of 93MHz and throughput of 1.488Gpixel/s with a cost of 56440 gates.

• Proceedings of the Korean Information Science Society Conference
• /
• 2007.10d
• /
• pp.613-618
• /
• 2007

현재 하나의 TV에 연결할 수 있는 수많은 기기들이 개발, 판매되고 있다. 이렇게 연결하는 방법 중 현재 많이 사용하고 있는 방법 중에 하나인 HDMI의 경우에 HDMI-CEC라는 기능을 도입해서 연결된 각각의 기기를 따로따로 컨트를 하지 않고 하나의 리모컨으로 적용하는 방안을 제시하고 있다. 현재 가정에서 사용하는 DVD-Recorder에 HDMI-CEC 기능을 대응하여, 사용자가 원하는 기능을 여러 개의 기기를 직접 제어하는 것이 아니라, 단 하나의 키 동작으로 여러 개의 기기를 동시에 제어하는 시스템을 설계한다면 사용자에게 많은 편의를 줄 수가 있다. 그러나, 이러한 시스템을 설계했을 경우에 사용자가 원하는 동작을 정확히 안 하는 문제, 반응 속도가 너무 느려서 사용자가 동작을 안 하는 것으로 착각하게 만드는 문제와 HDMI-CEC의 Spec에서는 제시하고 있지 않으나 사용자의 편의물 위해서 지원해야 하는 경우가 있을 수 있다. 이 논문에서는 HDMI-CEC와 PDC의 spec에 대한 설명을 하고, HDMI-CEC를 적용한 시스템에 대한 설계를 한다. 그리고, 그 시스템에서 발견된 문제 중 정확한 동작을 하지 않는 TV가 꺼져있는 OnTouchPlay의 경우의 대한 처리와, 반응 속도가 느린 경우인 시스템을 부팅하는 경우의 반응시간을 줄이는 방안, 그리고 HDMI-CEC의 spec에는 없으나 사용자의 편의를 위해서 지원해야 하는 기능들에 대해 논한다.

• Journal of the Korean Home Economics Association
• /
• v.50 no.8
• /
• pp.13-19
• /
• 2012

The present study explored the hours of living and playtime depending on existence of caregiver after school using the data from the Korean Children and Youth Panel Survey7071. KCYPS date collected on 1th, 4th and 7th grade children and their caregivers. The hours of living was categorized into sleeping, learning, reading and play times. Playtime was sub-categorized into time for using playing the computer/games, watching TV/DVD and playing with peer groups. The present study has shown that children in the fourth grade spent more time on learning, whereas reading children in the seventh grade spent more time on playing compared to those in other grades during the weekdays. Also, children in higher grades spent more time playing both on the weekdays and on the weekends. Students of all grades spent more time watching TV/DVD compared to other activities during the weekdays and the weekends. Children with a caregiver spent more time on learning and spent less time playing computer/game, watching TV/DVD and playing with peer groups than children without caregivers. As students moved up a grade, these results clearly appeared. Considering the results in this study, the allocation of hours of living and playtime of children altered depending on the existence of a caregivers.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.26 no.4
• /
• pp.631-636
• /
• 2002

It is necessary to improve mechanical and optical properties in the optical disk substrates as the information storage devices with high storage density using blue laser are being developed. Injection compression molding is regarded as the most suitable process to manufacture optical disk substrates for quality recording and read-out. In the present research, the effects of mold temperature and the insulation layer thickness on gapwise birefringence and the land-groove pattern were investigated. It was found that the values of the birefringence distribution were very sensitive to mold temperature history, and the level of birefringence reduced and, furthermore, the quality of replication was improved due to the insulation layer.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.13 no.1
• /
• pp.51-56
• /
• 2009

Purpose: Recently, most hospitals are introducing the PACS system and use of the system continues to expand. But small-scaled PACS called MicroPACS has already been in use through open source programs. The aim of this study is to prove utility of operating a MicroPACS, as a substitute back-up device for conventional storage media like CDs and DVDs, in addition to the full-PACS already in use. This study contains the way of setting up a MicroPACS with open source programs and assessment of its storage capability, stability, compatibility and performance of operations such as "retrieve", "query". Materials and Methods: 1. To start with, we searched open source software to correspond with the following standards to establish MicroPACS, (1) It must be available in Windows Operating System. (2) It must be free ware. (3) It must be compatible with PET/CT scanner. (4) It must be easy to use. (5) It must not be limited of storage capacity. (6) It must have DICOM supporting. 2. (1) To evaluate availability of data storage, we compared the time spent to back up data in the open source software with the optical discs (CDs and DVD-RAMs), and we also compared the time needed to retrieve data with the system and with optical discs respectively. (2) To estimate work efficiency, we measured the time spent to find data in CDs, DVD-RAMs and MicroPACS. 7 technologists participated in this study. 3. In order to evaluate stability of the software, we examined whether there is a data loss during the system is maintained for a year. Comparison object; How many errors occurred in randomly selected data of 500 CDs. Result: 1. We chose the Conquest DICOM Server among 11 open source software used MySQL as a database management system. 2. (1) Comparison of back up and retrieval time (min) showed the result of the following: DVD-RAM (5.13,2.26)/Conquest DICOM Server (1.49,1.19) by GE DSTE (p<0.001), CD (6.12,3.61)/Conquest (0.82,2.23) by GE DLS (p<0.001), CD (5.88,3.25)/Conquest (1.05,2.06) by SIEMENS. (2) The wasted time (sec) to find some data is as follows: CD ($156{\pm}46$), DVD-RAM ($115{\pm}21$) and Conquest DICOM Server ($13{\pm}6$). 3. There was no data loss (0%) for a year and it was stored 12741 PET/CT studies in 1.81 TB memory. In case of CDs, On the other hand, 14 errors among 500 CDs (2.8%) is generated. Conclusions: We found that MicroPACS could be set up with the open source software and its performance was excellent. The system built with open source proved more efficient and more robust than back-up process using CDs or DVD-RAMs. We believe that the operation of the MicroPACS would be effective data storage device as long as its operators develop and systematize it.

• Journal of Korean Electronics
• /
• v.25 no.11
• /
• pp.43-44
• /
• 2005

• Proceedings of the Korean Magnestics Society Conference
• /
• 2006.11a
• /
• pp.144-145
• /
• 2006