• Journal of Navigation and Port Research
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• v.40 no.6
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• pp.385-390
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• 2016

ELoran Systems can provide Position, Navigation, and Time services with comparable performance to Global Positioning Systems (GPS) as a back up or alternative system. High timing and navigation performance can be achieved by eLoran signals because eLoran receivers use "all-in-view" reception. This incorporates Time of Arrival (TOA) signals from all stations in the service range because each eLoran station is synchronized to Coordinated Universal Time (UTC). Transmission station information and the differential Loran correction data are transmitted via an additional Loran Data Channel (LDC) on the transmitted eLoran signal such that eLoran provides improved Position Navigation and Timing (PNT) over legacy Loran. In this paper, we propose a technique for adapting the delay time compensation values in eLoran timing receivers to provide precise time comparison. For this purpose, we have designed a system that measures time delay from the crossing point of the third cycle extracted from the current transformer at the end point of the transmitter. The receiver delay was measured by connecting an active H-field, an E-field and a passive loop antenna to a commercial eLoran timing receiver. The common-view time transfer technique using the calibrated eLoran timing receiver improved the eLoran transfer time. A eLoran timing receiver calibrated by this method can be utilized in the field for precise time comparison as a GNSS backup.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.3
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• pp.245-255
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• 2023

Time comparison techniques are necessary for generating and keeping Coordinated Universal Time (UTC) and distributing standard time clocks. Global Navigation Satellite System (GNSS) Common View, GNSS All-in-View, Two-Way Satellite Time and Frequency Transfer (TWSTFT), Very Long Baseline Interferometry (VLBI), optical fiber, and Network Time Protocol (NTP) based methods have been used for time comparison. In these methods, GNSS based time comparison techniques are widely used for time synchronization in critical national infrastructures and in common areas of application such as finance, military, and wireless communication. However, GNSS-based time comparison techniques are vulnerable to jamming or interference environments and it is difficult to respond to GNSS signal disconnection according to the international situation. In response, in this paper, Code-Division Multiple Access (CDMA) based All-to-All TWSTFT operation method is proposed. A software-based simulation platform also was designed for performance analysis in multi-TWSTFT signal environments. Furthermore, code and carrier measurement jitters were calculated in multi-signal environments using the designed simulation platform. By using the technique proposed in this paper, it is anticipated that the TWSTFT-based time comparison method will be used in various fields and satisfy high-performance requirements such as those of a GNSS master station and power plant network reference station.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.284-287
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• 1987

In this paper, the design and implementation of a multiprocessor based Die Bonder Machine for the semiconductor will be described. This the partial research result, that is, the 1st year portion of the project to be performed for a period of two years from June, 1986 to May, 1988. The mechanical system consists of the following three subsystems : (i) transfer head unit, (ii) die feeding XY-table unit, and (iii) plunge up unit. The overall control system is designed to be essentially a master-slave type in which each slave is functionally fixed in view of software and also the time shared common bus structure with hardwired bus arbitration scheme is utilized, the control system consists of the following three subsystems each of which employs a 16 bits microprocessor MC 68000 : (i) die bonder processor controller, (ii) visual recognition/inspection and display system, (iii) the servo control system. It is reported that the proposed control system were applied to Working Sample and tested in real system, and the results are successful as a working sample phase.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.4
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• pp.18-27
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• 2018

This study is a basic one analyzing the scenic characteristics that are created in Royal Garden in China while taking into consideration that Royal Garden in China is a fruit compiling all of the Chinese classical gardens. In case of Summer Palace in China, it adopted various kinds of landscape displaying techniques for fulfilling the desires of an Emperor who wanted to appreciate beautiful landscapes all the time. Accordingly, the scenic characteristics can be summarized as follows. First, Summer Garden creates various kinds of garden landscapes through various kinds of landscape creation techniques, such as, Borrowed Landscape, Central One, Background One, Symmetrical One, Axial One, Dividing One, Framed One, Window One and Complementing One, etc. Second, it was created in order for visitors to focus on appreciation of landscapes by allocating hard points while considering the symmetric structure, Structure of Long Corridor and Visual Physiology of a building on the basis of the South-North Pivotal Line. Third, it utilized the scenic spot transferring technique that introduces the landscapes of scenic spots in various regions of China to Summer Palace to be matched to the unique geological characteristics of Summer Garden. It was found that Summer Palace adopted the common landscaping techniques in Jiangnan Region of Ancient China since the landscape of Jichang Garden in Hangzhou and that of Shan Tang Jie in Suzhou are reproduced and transferred. It was found that 3 methods mentioned above have the effects that attract sightseers' eyes naturally and make their interests concentrated as well as reviving the feeling of space in a garden and creating abundant scenic beauty.

• Journal of Korean Library and Information Science Society
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• v.53 no.3
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• pp.73-94
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• 2022

Florence is the cradle of the Italian Renaissance. It is the result of a combination of medieval humanists' exploration of ancient Greek and Roman knowledge and culture, the leadership of great monarchs and priests, patronage of the Medici family, etc., free-thinking and creativity of artists, and critical consciousness and cultural needs of citizens. However, the Florentine Renaissance could not have blossomed unless the Medici family had collected ancient manuscripts and translations, and built libraries to preserve and provide literature. Based on this logical basis, this study outlined the Florentine renaissance and historic libraries, analyzed the collection and composition of favorite books of the Medici family, and traced the architectural characteristics and metaphors of the Medici libraries, The San Marco Library (Michelozzo Library), Library of Badia Fiesolana, and the San Lorenzo Library (Laurentian Library) were the priming and birthplace of the Florentine Renaissance despite of many difficulties, including earthquake, fire, restoration, transfer, seizure, and closure. In particular, the San Marco Library, which was opened in 1444 based on the financial support of Cosimo de' Medici, Michelozzo's design, and Niccoli's private collections was the first common library in the Renaissance period. And the architectural highlight of the Laurentian Library, which opened in 1571 under the leadership of Giulio (Papa Clemente VII), is Michelangelo's staircase, which symbolizes 'from ignorance to wisdom', and the real value of the content is the ancient manuscripts and early printed books, which were collected by the humanist Niccoli and the Medici family. In short, when discussing the Florentine Renaissance, Medici's collection and historic libraries are very important points. The reason is that the ancient collections were not stuffed products, but syntactic semiotics, and the libraries are telescopes that view the history of human knowledge and culture and microscopes that create knowledge and wisdom. If records dominate memories, libraries accumulate records. Therefore, long breathing and time capsule strategies are also required for the development and preservation of retroactive books in domestic libraries with a relatively long history.