• Journal of Information Processing Systems
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• v.19 no.3
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• pp.394-406
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• 2023

In this study, a real-time surveillance system using Internet of Things technology is proposed for vaccine cold chains. This system fully visualizes vaccine transport and storage. It comprises a 4G gateway module, lowpower and low-cost wireless temperature and humidity collection module (WTHCM), cloud service software platform, and phone app. The WTHCM is installed in freezers or truck-mounted cold chain cabinets to collect the temperature and humidity information of the vaccine storage environment. It then transmits the collected data to a gateway module in the radiofrequency_physical layer (RF_PHY). The RF_PHY is an interface for calling the bottom 2.4-GHz transceiver, which can realize a more flexible communication mode. The gateway module can simultaneously receive data from multiple acquisition terminals, process the received data depending on the protocol, and transmit the collated data to the cloud server platform via 4G or Wi-Fi. The cloud server platform primarily provides data storage, chart views, short-message warnings, and other functions. The phone app is designed to help users view and print temperature and humidity data concerning the transportation and storage of vaccines anytime and anywhere. Thus, this system provides a new vaccine management model for ensuring the safety and reliability of vaccines to a greater extent.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.5 s.98
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• pp.124-131
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• 1999

DVD(Digital Versatile Disk) is the data storage media devised to make high storage density and high speed data input/output possible. For example, a whole length movie can be stored in a disk as large as a CD(Compact Disk). Therefore higher rotational speed and better accuracy in optical pick-up are required compared with the existing optical storage device. Without these operational functional requirements being satisfied DVD will lose its place as the high capacity storage device. This paper evaluated whether the currently developed DVD satisfies the requirements and provides improved methods with the Axiomatic Approach which is superb in evaluating and designing newly concepted designs.

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.243-245
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• 2009

광학 현미경의 분해능이 파장에 따른 회절에 의해 결정된다. 이것을 극복하기 위해서 나노미터까지 분해능을 향상시키기 위해서 근접장 광학이 각광을 받고 있다. 본 보고에서는 흡수 에지 근처의 위상변화 특성에 기인한 초해상을 보고한다.

• 정보저장시스템학회:학술대회논문집
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• 2005.10a
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• pp.124-127
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• 2005

Rewritable optical memory devices such as an CD-RW and DVD+RW are data storage media, which take advantage of the different optical properties in the amorphous and crystalline states of phase change materials. The switching property, structural transformation, transformation kinetics and chemical bindings of $Ge_xSb_{100-x}$($6{\le}x{\le}$34) were studied to investigate the feasibility of applying $Ge_xSb_{100-x}$ alloys in optical memory. The $Ge_xSb_{100-x}$ thin film was deposited by RF magnetron co-sputtering system and phase change characteristics were investigated by X-ray diffraction (XRD), static tester, inductively coupled plasma atomic emission spectrometer (ICP-AES) and atomic force microscopy (AEM). Optimum fiim composition of $Ge_xSb_{100-x}$ was studied and its minimum time fur laser induced crystallization and optical contrast fur phase transition was performed. These results might be correlated with the binding energies between Ge and Sb, and indicate that $Ge_xSb_{100-x}$ have an potential far optical memory applications.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.4 s.97
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• pp.64-70
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• 1999

A new multi-beam optical system is presented on the grounds of tri-positioning systems in this paper. The system has been developed to improve the data transfer rate for the optical disk system. The actuating system is composed of a tracking and focusing actuating system basically and a newly developed beam rotating actuator. The beam rotating actuator is employed in a multi-beam optical system to trace more than one track simultaneously. The multi-beam optics is established through the optical simulation and several experimental trials. The differential phase tracking method is used in the tracking error signal detection based on the only one beam spot. We also analyze the characteristics of multi-beam optical system. The experimental result shows that the multi-beam positioning system has performance adequate to the multi-beam optical disk system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.964-967
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• 2001

Aspherical lens with the higher numerical aperture has been needed in the optical storage device to increase the recording density on the disk. However, high numerical aperture means the large slope angle at the clear aperture of the lens. Therefore, the measurement and manufacturing technique including the lens molding process for the slope angle should be developed. In this paper, the evaluation technique was described for the optical performance of the aspherical lens. Aspherical form error brings about the wavefront error and the side lobe of the beam intensity profile. A schematic diagram of the aspherical lens manufacturing was drawn to explain the aspherical form error compensation. Finally, form error of the aspherical lens was defined and plotted using the raw data of the Formtalysurf.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1256-1258
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• 1993

Optical data storage offer high density storage and archival storage capability. In this study, we selected the ablation mechanism-one of an irreversible recording system-using the antireflection trilayer(ART) structure. Optical recording medium is a $(Te_{86}Se_{14})_{50}Bi_{50}$ thin films. Actually, ART structure is fabricated and compared to monolayer structure. ART structure leads to the reduction of recording power as well as an increase in the effciency compared to the monolayer structure.

• 정보저장시스템학회:학술대회논문집
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• 2005.10a
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• pp.47-52
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• 2005

A lot of information storage devices have been introduced and developed for recently years. The trends of those devices are high capacity, compact size, low power consumption, reliability, and removability for data interchange with other device. As a satisfaction of these trends, near-field technique is in the spotlight as the next generation device. In order for a near-field recording to be successfully implemented in the storage device, a slider and suspension is introduced as actuating mechanism. The optical slider is designed considering near-filed optics. Suspension is not only supports slider performance, and tracking servo capacity but also meets the optical characteristics such as tilt aberration, and guarantee to satisfy shock performances for the mobility fir the actuator. In this study, the optical slider and the suspension for near-field probe array are designed and analyzed considering dynamic performance of head-gimbal assembly and shock simulation..

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.6
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• pp.1361-1373
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• 2016

Recently the need for user authentication with increasing, there are a variety of mechanisms, such as password, graphic authentication, token, biometrics and multiple authentication. in particular, the data of the 2-dimensional(2D) factors such as password, graphic authentication, biometrics is used because of the convenience. The stored information is problematic in that additional data recording needs to be performed whenever authentication data is updated. Furthermore, this storage method is problematic in that the time it takes to perform authentication increases because the time it takes to compare storage data with authentication data increases in proportion to an increase in the amount of the storage data. Accordingly, authentication through the rapid comparison of storage data with authentication data is a very important factor in data recording and authentication technology using memory. Using the three-dimensional(3D) optical memory by variously changing the recoding elements during recoding of data constitutes the way that multiple recoding different data storage. This enables high-density recoding in this way, and by applying the possible parallel processing at the time of recording and restoring method, provided that it is possible to quickly record and restore the data. In addition, each time to solve problems that require additional data recorded by a combination of the stored data record in the old data using a combination of the authentication. The proposed mechanism is proposed an authentication method using scheme after the recoding data in 3D optical memory to apply the conditions corresponding to the recoding condition when restoring the recorded data and through the experiment it was confirmed possible application as an authentication mechanism.

• Transactions of the Society of Information Storage Systems
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• v.2 no.1
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• pp.21-25
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• 2006

The new multimedia information environment requires smaller optical data storage systems. However, one of the difficulties encountered in designing small form factor(SFF) optical pick-up is to emit the heat which is generated from laser diode(LD). Heat generated at the LD can reduce the optical performance of the system and the lifetime of LD. Therefore, it is important to include the thermal design in the design stage of SFF optical pick-up system for high performance and the longer lifetime of LD, and furthermore, to analyze the thermal characteristics of LD in detail micro heat transfer analysis is necessary. In the present study, micro heat transfer analysis was performed using the finite element method for the $28{\times}11{\times}2mm^3$ super slim swing-arm type optical pick-up actuator for Blu-ray disk. Two different materials were used for a swing-arm; a double layer polycarbonate/steel structure and a single aluminum structure.