• International Journal of Precision Engineering and Manufacturing
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• v.8 no.2
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• pp.70-74
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• 2007

This paper describes the development of a nano-positioning system for nanoscale science and engineering. Conventional positioning systems, which can be expensive and complicated, require the use of laser interferometers or capacitive transducers to measure nanoscale displacements of the stage. In this study, a new self-displacement sensing (SDS) nano-stage was developed using mechanical magnification of its displacement signal. The SDS nano-stage measured the displacement of its movement using a position-sensitive photodiode (PSPD), a laser source, and a hinge-connected rotating mirror plate. A beam from a laser diode was focused onto the middle of the plate with the rotating mirror. The position variation of the reflected beam from the mirror rotation was then monitored by the PSPD. Finally, the PSPD measured the amplified displacement as opposed to the actual movement of the stage via an optical lever mechanism, providing the ability to more precisely control the nanoscale stage. The displacement amplification process was modeled by structural analysis. The simulation results of the amplification ratio showed that the distance variation between the PSPD and the mirror plate as well as the length L of the mirror plate could be used as the basic design parameters for a SDS nano-stage. The PSPD was originally designed for a total travel range of 30 to 60 mm, and the SDS nano-stage amplified that range by a factor of 15 to 25. Based on these results, a SDS nano-stage was fabricated using principle of displacement amplification.

• Journal of the Korean earth science society
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• v.35 no.5
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• pp.324-332
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• 2014

Many problems in naming natural monuments have been repeatedly argued by many researchers, and four different types of naming problems were identified: 1) name of unknown nationality (natural monument no. 82 and 108), 2) morphological name rather than scientific name (natural monument no. 180, 295, and 409), 3) name of fable character (local cultural property of Changnyeonggun), and 4) scientifically wrong name (natural monument no. 413). Among them, two cases (case 3 and 4) using wrong names are found in natural monument of geologic heritages, which should be ascribable to a hasty designation without an accurate and thorough scientific research. In order to solve these problems and to establish an ideal policy in designating natural monument, National Research Institute of Cultural Heritage has been carrying out a research project of "Pre-study and Post-designation (PSPD)", especially targeting the rod-shaped stromatolite. It is likely that this new strategy of PSPD is a unique and the first step to solve many problems in designating and naming geologic heritages as natural monuments. As a consequence, we strongly suggest that PSPD system must be applied to natural monument designation as an institutional arrangement.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.2287-2290
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• 2003

In this paper, an image vector quantization method is proposed not only to improve the compression ratio but also to reduce the computation cost. The proposed method could save the computation cost of codebook generation and encoding by using the modified LBG algorithm of Partial Search Partial Distortion (PSPD) in wavelet domain, by which the code book was constructed together with the partial codebook search, the partial code vector elements, and the interruption criterion. We have designed and implemented the vector quantizer to verify the improvement in reducing compression ratio in encoding processing and reducing the computation cost.

• Proceedings of the Korea Crystallographic Association Conference
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• 2002.11a
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• pp.36-36
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• 2002

To Establish of standard technique of length measurent in 2D plane, we develope AFM system. The XY scanner scans the sample only in XY plane, while the Z scanner scans the specimen only in Z-direction. Cantilever tip is controlled to has constant height relative to speciman surface by feedback of PSPD signal. To acquire high accuracy, Z-axis measuring sensor will be added.(COXI or others). In this paper we design XYZ stage suitable for this AEM system. For XY stage, single module parallel-kinnematic flexure stage is used which has high orthogonality and minimum out-of-plane motion. To obtain best performance optimal design is performed. For XY stage, to be robust about parasitic motion optimal design of maximizing Z and tilt stiffness is performed under the constraint of motion range and stage size. And for Z stage, optimal design of maximizing 1st resonant frequency is performed. Because if resonant frequency is get higher, scan speed is improved. So it makes reduce the error by sensor drift. Resultly XYZ stage each have 1st natural frequency of 115㎐, 201㎐, 2.66㎑ and range 109㎛, 110㎛, 12㎛.

• Korean Journal of Social Welfare
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• v.49
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• pp.264-295
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• 2002

This study aims to identify the enactment factors of the National Basic Livelihood Institution in context of policy making process by using Kingdon's policy Stream Model. The findings of this study can be summarized as follows. First, an economic crisis has worsened social problems, and the president Kim Dae-jung recognized these problems as serious and worried about social confusion and polarization. Second, NGOs as like People's Solidarity for Participatory Democracy put efforts into enacting the Act. Also, the president Kim's government faced a series of political crisis and needed political solution including foundation of a new party, which considered social welfare most important. Third, the PSPD designed the Act. But the alternatives of related government ministries were not selected. In conclusion, the National Basic Livelihood Institution was enacted by the combination of these three factors stream. Especially the political stream was strongest.

• Restorative Dentistry and Endodontics
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• v.26 no.2
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• pp.134-140
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• 2001

The polymerization shrinkage of composite resins is an important drawback although the composites have many advantages-more esthetic and conservative than metallic restoratives etc. The purposes of this research were to develop a new measurement method and to manufacture an instrument that can measure the initial dynamic volumetric shrinkage of composite resins during polymerization. The instrument was basically an electromagnetic balance that constructed with a force transducer using position sensitive photo detector(PSPD) and a negative feedback servo amplifier of proportional-derivative(PD) controller. The volumetric change of composites during polymerization was detected continuously as buoyancy change in distilled water by means of Archimedes's principle. It was converted to continuous electrical voltage signal in real time. The signal was properly conditioned and filtered and then it was stored in computer by a data acquisition(DAQ) board. By using this electronic instrument. the dynamic patterns of the polymerization shrinkage of eight commercial(Z-100, DenFil, AeliteFil, Z-250, P-60, SureFil, Synergy compact, and Tetric ceram) composite resins were measured and compared. The results were as follows. 1. From this project of developing instrument, the ability has been achieved that can acquire and process data of electrical signal transformed from various physical phenomenon by using temperature, displacement. photo. and force transducer. As a consequence, the instrumentation and measurement system used to analyze the physical characteristics of various dental materials in dental research field can be designed, manufactured and implemented in lab. 2. This instrument has some advantages. It was insensible to temperature change and could measure true dynamic volumetric shrinkage in real time without complicated process. It showed accuracy and high precision results with small standard deviation. 3. The polymerization shrinkage of composites was significantly different between brands and ranged from 2.47％ to 3.89％, The order of polymerization shrinkage was as follows, in order of increasing shrinkage, SureFil, P60, Z250, Z100, Synergy compact. DenFil, Tetric ceram, and AeliteFil. 4. The polymerization shrinkage rate per unit time, dVol％/dt, showed that the instrument can provide an indirect research method for polymerization reaction kinetics.

• The Korean Journal of Archival Studies
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• no.22
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• pp.37-76
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• 2009

This paper aims-through comparative research on two organizations and use of political process theory-to analyze the historical development of, current issues related to and the characteristics of the new transformation of the Freedom of Information Movements (FOIMs) in South Korea. In the ten years since the Freedom of Information Act (FOIA) took effect in 1998, Korean FOIMs have developed along the following course: 'emergence' (1998), 'expansion and extension' (1999-2004), 'institutionalization and retro-institutionalization-' (2005-2008). Specifically, in the early stage of FOIMs, the Freedom of Information (FOI) department of the People's Solidarity for Participatory Democracy, established in 1998, had led the FOI movement by initiating reform of the FOI institution and advocating an end to old practices. Paradoxically, however, following the institutional progress of FOI under the Roh Moo Hyun government, the vitality of FOIMs seemed to be weakening. And under the Lee Myung Bak government, which is showing regression in both the FOI institution and practices, the 'dual transformation' of the FOIMs is being led not by old groups but by new ones. The Center for Freedom of Information and Transparent Society(CFOI), which was founded in 2008, has journalists, researchers of archival studies, citizens, lawyers and nongovernmental activists as members. Through its blog style Homepage, countless reports are becoming "open to the public" and "share with the public." And its various civic education programs are interactive bridges which enable mutual communication between the Center and citizens. CFOI is expanding the FOI movement in different ways than the traditional activists such as the FOI department of the PSPD department, which worked through methods such as policy proposals, disclosing information litigation, comments and public statements, and hosting forums. CFOI is leading the 'dual process of transformation' of FOIMs, namely the transformation from an 'advocacy' movement to an 'empowerment' movement and transformation of the FOI movement's framework from "open to the public" to "share with the public."