• Journal of Institute of Control, Robotics and Systems
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• v.5 no.1
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• pp.47-53
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• 1999

CD-ROM(Compact Disk-Read Only Memory) is very attractive storage media because it has much storage space but is small size and portable. Optical pickup, one of the most important parts for reading data on a CD-ROM, is not produced tuned up. For the use of goods, we must tune up the optical pickup by adjusting the screw for adjustment. First, we developed analog servo system for optical pickup tuners. For eliminating some problems in analog servo system, this paper designed the modeling of digital servo system for optical pickup tuner. Though the characteristics of optical pickup are changed, the digital servo system for optical pickup tuner can easily apply to all pickup, and can reduce the measurement error among the optical pickup tuners. For the purpose of confirming the designed digital servo system, we produced data that specify the disk vibration and the disk eccentricity, and simulated servo system with MATLAB.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11b
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• pp.967-971
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• 2001

The frequency characteristics of the optical pickup are investigated indirectly from the bode diagram of the open loop system and the actuator. However, there is necessity of acquiring the optical pickup bode diagram in a view of the differences in the frequency characteristics. One of the differences is that bode diagrams of the optical pickup are differ to that of the actuator and the other is that bode diagrams of the open loop system include controller, gains and filters. So this paper presents the method acquiring the optical pickup bode diagram. In addition, usefulness of the optical pickup bode diagram was demonstrated by being applied to the optical pickup design. The reason of reducing the development period and acquiring the frequency characteristics of the optical system, the optical pickup bode diagram has many merits in the optical pickup design before acquiring the stable bode diagram of the open loop system.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.5
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• pp.417-422
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• 2014

A guitar pickup is a transducer that converts string vibration to an electrical signal. The magnetic and piezo pickups are the most commonly used for the respective electric and electroacoustic guitars. The magnetic pickups are prone to magnetic interference between the steel strings and permanent magnets, while the piezo ones are not free from signal inference between the strings. Thus, this paper presents the development of an optical pickup for the electroacoustic guitar. The proposed optical pickup has the top-to-bottom structure. It uses two of Infrared (IR) Light Emitting Diode (LED) and one photodetector. The developed optical pickup is subjected to the evaluation with commonly used piezoelectric pickup. It becomes obvious that SNR with the optical pickup is increased by 45 percent in average, compared with the piezoelectric pickup. It can be concluded that the developed optical pickup has a potential to be applied to the acoustic guitar.

• Transactions of the Society of Information Storage Systems
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• v.1 no.1
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• pp.42-47
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• 2005

We developed an optical pickup system which is used fer Blu-ray Disc. A liquid crystal element was used to make compensation for spherical aberration. Spherical aberration is a difficult problem in the optical pickup system for Blu-ray Disc. To reduce the effects of wavelength variation from the laser source, we designed a diffraction optical element. We took a measurement of all of the parts used to make a pickup system and validated the performance of each part. Then, we made a performance test fur the optical pickup system which we developed for Blu-ray Disc and the results were satisfactory.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.3-4
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• 2011

In this paper, a new pickup with compensation winding for KAIST OLEV is proposed. The proposed compensation winding increases induced voltage at a pickup and can be used for tuning of a pickup. The detailed theoretical analysis is given. It is expected to enhance the performance of OLEV pickup,

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.346-350
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• 1996

In optical disk drives, one of commonly used pickup actuator is a Sliding and rotary type of pickup actuator which is cheaper than other pickup actuators and has simple assembly. However, it reported that non-linearity due to friction between a shaft and a sleeve had to be considerably analyzed in design and servo system in employing this type of pickup actuator. In this paper, this friction is modeled as a Coulomb's friction and the effect of friction is examined in the simulation. A digital servo system is applied to pickup actuator with friction in order to have good focusing servo. To enhance focusing servo performance using digital servo merit, frist PD-controller is applied to have fast response performance, second lead-lag compensator is applied to have stable focusing performance.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.337-338
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• 2007

The present paper proposes the method which improves a record and remaking efficiency of the optical pickup as applying the mirror where Phase Shift(PS) principle is applied to optical pickup. Plan to get a circularly polarized light quality above quality which is embodied through Existing Quater Wave Plate(QWP) and a function of total reflection mirror as applying PS mirror which integrates QWP with the function of the total reflection to optical pickup. In the present paper, embody circularly polarized light quality through applying PS mirror to optical pickup, and it through, plan to propose to come true the optimization of recording and remaking CD/DVD disc.

• Industrial Engineering and Management Systems
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• v.2 no.1
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• pp.28-34
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• 2003

The fundamental design issues that arise in the pickup and delivery system planning are optimizing the system with minimum cost and maximum throughput and service level. This study is concerned with the development of pickup and delivery system with customer responsive service level, DCM(Demand Chain Management). The distribution process and service map are consisted of manufacturing, warehousing, and pickup and delivery. First we formulated the vehicle pickup and delivery problem using GIS-VRP method so as to satisfy the customer service requests. Second, we developed a GUI-type computer program using AVL, automated vehicle location system. The computational results show that the proposed method is very effective on a set of test problems.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.857-860
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• 2005

A guitar pickup transforms the vibration of strings to the electric signals, and deliveres them to an amplifier. A piezo pickup has interference problem between strings. The paper aims to improve sound quality for an electro-acoustic guitar through the finite element analysis. Firstly the conventional pickup is modeled and analyzed with a commercial program called ANSYS. It is obvious that there exists interference between the strings. The structural modification of the pickup is performed, based on the beam theory The modified structures are suggested, modeled and analyzed. Then the result are compared with those in the conventional pickup. It can be concluded that the interferences with the modified structures are much less than those with the conventional structure.

• Asia pacific journal of information systems
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• v.32 no.1
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• pp.51-69
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• 2022

This study examines how consumers' intention to use a curbside pickup responds to the COVID-19 vaccination rates. With our first survey conducted in March 2021, we find that a low (high) vaccination rate is associated with consumers' high (low) intention to maintain contact avoidance and their high (low) anticipation for shipping delays. Heightened contact avoidance and anticipation for shipping delays may encourage consumers to use a curbside pickup. Our results also show that when a product is needed immediately, and a consumer expects shipping delays, s/he is more likely to use a curbside pickup. However, with our second survey conducted in November 2021, we find heterogeneous consumer responses to the vaccination rates. Specifically, consumers' political affiliation moderates the relationship between the vaccination rates and their intention to maintain contact avoidance. The association between the vaccination rates and the anticipation for shipping delays is also weakened compared to March 2021. Our empirical results illustrate how consumers' intention to use a curbside pickup emerges and changes amid the COVID-19 pandemic.