• Nuclear Engineering and Technology
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• v.49 no.4
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• pp.881-885
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• 2017

This work presents a new technique for discriminating between alpha particles of different energy levels. In a first study, two groups of alpha particles emitted from radium-226 and americium-241 sources were successfully separated using a CR-39 microfilm of appropriate thickness. This thickness was adjusted by chemical etching before and after irradiation so that lower-energy particles were stopped within the detector, while higher-energy particles were revealed on the back side of the detector. The number of tracks on the front side of the microfilm represented all alpha particles incident on that side from the two sources. However, the number of tracks on the back side of the microfilm represented only the long-range alpha particles of higher energy that arrived at that side. Therefore, by subtracting the number of tracks on the back side from the number of tracks on the front side, one could easily determine the number of tracks for the short-range alpha particles of lower energy that remained embedded in the microfilm. Discrimination of the two energy levels is thus achieved in a simple, fast, and reliable process.

• Progress in Medical Physics
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• v.15 no.2
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• pp.59-62
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• 2004

We developed very small parallel plate radiation detector by using our existing experience of mating radiation dosimeter and capability of analyzing characteristics of dosimeter. The radiation detector was consisted of microfilm and carbon electrode. The detector was parallel plate type of all-filled ionization chamber. The ionization chamber had been fabricated using an acrylic plate for the air cavity and carbon coated microfilm for electrical configuration. The alr gap between two electrodes was 0.48 mm. The diameters of collect electrode and guard electrode were 3.3 mm, 5 mm respectively. The diameter of high voltage electrode was 5 mm. Nominal sensitive volume of the chamber was 0.016 ㎤. The major parameters of the chamber characteristics such as leakage current, reproducibility, dose rate effect, and polarity effect were measured. The experimental results were as followings. Leakage current was 0.1 pA. Standard deviation of reproducibility was less than 0.1%. Dose rate effect was less than 1.5%. Polarity effect was less than 2.4%. These data were comparable to those of commercially available dosimetric system for QA-purpose. As the result, we found that the radiation detector consisting of the ionization chamber, microfilm and carbon electrode, was satisfactory for the purpose of the small field dosimetry in size and characteristics. In the future, We will try to refine the dosimeter for use in very small volume.

• The Korean Journal of Archival Studies
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• no.63
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• pp.227-268
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• 2020

Microfilm has been used as an important media for enhancing the long term preservation and improving access to records. However, because of technological changes, there have been discussion about whether we should keep using microfilm. This paper presents survey results to review the preservation methods such as microfilming and digitization. The content is organized according to the trends found in the survey from six archives and libraries, including Germany, France, the United Kingdom, and Japan. Moreover, we refer to other papers from the USA and Japan to require further review if we can accept digitized records as the original records, etc. The rest consists of four parts: the use of microfilm as a storage media for preservation, the authenticity of digitized records, the management of records on microfilm, and the preservation of electronic media. Finally, we would like to suggest the way to improve preservation systems and digitize records more widely.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.12 no.2
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• pp.71-84
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• 2001

The purpose of this study is to provide the methods of preservation for paper, microfilm, digital media. First of all, for acidic papers produced in 19~20 centuries, this study evaluates and analyses deterioration and factors causing deterioration. For book, also, environmental condition for preservation, and a preservation mechanism through acid-free procedure were suggested. Second for microfilm, it emphasized physical and chemical properties, oxidised substance during developing film, materials related to preservation. Third, for digital storages, storage conditions and needs, such as life-cycle and capacity were introduced.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.12
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• pp.1353-1361
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• 1992

Holographic optical element(HOE) is fabricated with the properties of lightweight, thin thickness and interconnectivity for free space. Particularly, HOE for optical interconnection and multiple image processing should have a high efficiency and equal spot intensity, Nonlinear equations for 2-dimensional binary phase grating(BPG) structure is solved by computer simulation based on modified Newton method. Computer-generated pattern drawn by plotter is scaled down and translated into the microfilm. After contact printing between the microfilm and silver halide hologram film, phase diffraction grating produces the $5{\times}5$ multiple spots. Experimental results are shown that bleached phase grating has a high efficiency and equal focused beams except central zero order.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2006.08a
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• pp.134-134
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• 2006

• Korean Journal of Optics and Photonics
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• v.8 no.4
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• pp.255-259
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• 1997

In this paper, the result of a performance study on a home-built spinning disk type confocal microscope is presented. The confocal microscope was fabricated with a Nipkow disk made of the made of the microfilm. The throughput of the disk was 0.5%, allowing the observation of specimen with higher reflectivities only. A laser diode at 692.7nm was used as the light source. The topographic structures of a PC ROM and the CD ROM were observed with sufficient reliability, while the effect of the convolution of the beam size with the finite object size was found dominant. Also the shadowing effect by the etched pattern was observed.

• The Korean Journal of Archival Studies
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• no.11
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• pp.144-180
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• 2005

Automation can help organisations implement authentic and reliable record management practices, through the improved tracking of records through their life cycle as well as the consistent application of records schedules and descriptive standards. Maintaining evidence through authentic and reliable records is a cornerstone of good business practice and helps ensure a valuable record for society. This paper provided understanding of establishing records and archives management system(ARMS) with the case of the Jogye order of Korean buddhism. This system was designed to control records in the whole step from creation to preservation so that it automatized process to organize and control current records and to preserve archives. This system covers a wide range of archival functions including appraisal, arrangement and description, transfers, access, location and space management, microfilm management and destruction. This system will be applied records management of similar organization because of designing from the archival scientific point of view. Also, development process of this system will help archivist to build ARMS based on archival needs of institution.

• Progress in Medical Physics
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• v.16 no.3
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• pp.111-115
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• 2005

We have designed the multi channel detector for the quality assurance of clinical photon beams. The detector was composed of solid phantom inserted by six plane-parallel ionization chambers at different depth. The chamber as a mini plane parallel chamber was made of carbon coated microfilms. In this study the electrical characteristics of the six chambers in the solid phantom were evaluated using 6 MV photon beam. The leakage currents were less than 0.5 pA, reproducibility was less than 0.5$\%$, linearity was less than 0.5$\%$, and dose rate effect was less than 0.7$\%$. In addition the effect of dose variation from other chambers was estimated to maximum 0.8$\%$ approximately. The developed detector can be used for quality determination in output dosimetry or measurement of percentage depth dose approximately for clinical photon beam.

• Journal of the Korean Society for Library and Information Science
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• v.39 no.4
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• pp.177-192
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• 2005

Traditional paper records have two aspects such that the paper records are information, and are information media itself. The preservation media for the paper records seems to be another forms for original ones including microfilm and optical disks. On the other hand, new-coming electronic records lack the aspect of information media. To guarantee the existency of the original electronic records we need the preservation media for the electronic records, different from the media for the traditional paper records. The preservation media helps the Authenticity, integrity, and usability as well. This paper describes the need for the preservation media, identifies problems on the existing concept for them, derives the principles to resolve the problems, and suggests the management policy based on the principles.