• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.239-244
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• 1998

ESP(Electronic Speckle Pattern Interferometry) is an optical technique to measure deforamtion of engineering components and materials in industrial areas. ESPI, a non-contact and non-destructive measuring method, is capable of providing full-field results with high spatial resolution and high speed. One of important application aspects using electronic speckle pattern interferometry is to generate contours of a diffuse object in order to provide data for 3-D shape analysis and topography measurement. The electronic speckle contouring is suitable for providing measurement range from millimeters to several centimeters. In this study, we introduce the contouring method by modified dual-beam speckle pattern interferometer and a shift of the two illumination beams through optical fiber in order to obtain the contour fringe patterns. Before the experiments, we performed the geometric analysis for dual-beam-shifted ESPI contouring. And by this geometric analysis, we performed the electronic speckle contouring experiment. We used 4-frame phase shifting method with PZT for quantitative analysis of contour fringes. Finally, we showed good agreements between the geometric analysis and experimental results.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.1
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• pp.9-17
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• 1990

This study was carried out in the Haenahm county as a part of project, the'89 Comprehensive Planning of Rural Area. In order to increase household income of rural area and to meet increasing tourism demand in urban area, several tourism development directions and strategies were suggested in terms of resources, services, and transportation. The major results of this study are summarized as follows ; 1) Core tourism market has to be maintained by inforcement of unique image of the Haenahm county, such as the southern extremeity of Korean peninsula and tourism resources rich land. 2) New tourism products need to be introduced to attract fringe market of this area by use of natural and cultural resources in the Haenahm county, such as terrain, climate, provincial park, music, dance and artifacts. 3) image of this county as a touristic resort would be escalated by development of high quality andclusterized accommodation in urbanized area of the Haenahm county 4) Development of private lodging, production of local brand by native food, beverage and artifacts, introduction of festival by folk song and folk dance would be helpful to stabilize a seasonal fluctuating demand level of ourismandlocalresidentsincome. 5) Diversification of tourism product needs to be provided for tourists in order to increase chances for enjoyment in the destination and to be involved in socially comfortable atmosphere. 6) Package tour by diversification of touristic subregions in this county and linkage system with touristic regions of other counties would helpful to lead visitors to stay long, resulting in increased expenditure.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.5
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• pp.161-170
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• 1994

This paper presents the performance and problems in analysis method and testing system of Electronic Speckle Pattern Interfermetry(ESPI) method, in measuring two-dimensional in- plane displacement. The analysis result of measurement by ESPI is quite comparable to that of measurement by strain gauge method. This implieds that the method of ESPI is a very effective tool in non-contact two-dimensional in-plane strain analysis. But there is a controversial point, measurement error. This error is discussed to be affected not by ESPI method itself, but by its analysis scheme of the interference fringe, where the first-order interpolation has been applied to the points of strain measured. Further development of advanced first-order interpolation method is being undertaken for the more precise in-plane strain measurement.

• Journal of the Korean Society for information Management
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• v.5 no.1
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• pp.53-78
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• 1988

The purpose of this study is to verify the factors determining core journals in a field based upon the results of the citation analysis of the journals in the field of Korean History(KH). In order to verify the determinant factors, dividing the articles of the KH journals into their novelty and author's seniority, the following hypotheses were established. Hypothesis 1: When a KH journal publishes more articles on prehistoric and ancient eras than others, the journal will have higher chance to be included in the core journals. Hypothesis 2: When a KH journal publishes more articles by senior researchers than others, the journal will have higher chance to be included in the core journals. To achieve the purpose, the cited articles found in the two sample journals, namely, Backsan Hakbo and Hanguksa Yongu were analysed during the past 20 years from 1962 to 1981. Applying the Hirst's Discipline Impact Factor method to the the study, Historical Science Impact Factor(HSIF) on the samples itself and the historical era dealt with in the articles and the seniority of the authors during every five-year period. Based upon thr present study to ver~fy the two hypotheses, the following conclusions have been reached. 1) Tht. most influencing sublect mattcr era or1 thix liSIF of the lo~lrual is arranged in prehistoric arid ancient, Koryo, Chosun, recent era, and the others by order of era. 2 ) Clial~g~~lg a fringe or semicore journal u~to a core j ~ u r n a l , very IISIF' 011 it> article e r a 1s grown up arrd prcllistoric a ~ ~ d ancierlt era:. are, s p c c ~ a l l ~ , incr.eased high relatively. Char~ging a core journal int:~ a fr~ngr or semicort. journal, t.very IISIF ti dropped and prel~istc~ric and ancieut taras arc, fallen sharp relatively. 3) The most irlflr~encin~ s~niority 011 the t1SII- of ihc journal I. the senior.., written or1 prehistoric and ancient eras. Above all, the senilir'b HSIF olr prehistoric anti anclent e r a s a r e most ~nfluencing the cliangi~rg of the core journal into the fringe ur bemicore. .i) flypothesis fl is no1 vcrif~ed i r t general. T l ~ e rt, lative connections bet wee^^ the senior's HSIF 011 each era and tht, ~ l ~ a l ~ g i t l g of the tort. ji1ur.tia1 arc \:er~fied in part hut r~ot in the wliole. 5) 'The reason why the 11SIF or1 prehistori~. arid ar~cic~nt e r a s is higl~er than others can be assumed becaltic the new <, xcavations a r r contit~ued actively i l l the prrsr.llt as to the relics arid remains or1 that eras. Accordingly, the HSIF' r i l l thr 11ew 3ubject matter l~ke arcl~acmlogy trends to grow up greatly. Bctween the senior's and juriior's JISIE', junior'.; is higl~er than s., nior's except ancient e r a . That reason can be assumed bccausr Iunlorb t r j to solve the ex~sting problems thr~urglr their ow11 new viewpoints and sights. So, i t should be studied whether the 11SlF on the artic1t.s of the new subject matters and viewpoirrts is influenced to the changing of the core jorlrnal or not.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.2
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• pp.118-126
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• 2004

Recombinant E.coli ACV 1003 (recA::lacZ) releasing ${\beta}$-galactosidase by a SOS regulon system, when exposed to DNA-damaging compounds, have been used to effectively monitor endocrine disruptors. Low enzyme activity of less than 10 units/mL, corresponding to a $\mu\textrm{g}$/L(ppb) range of an endocrine disruptor (tributyl tin, bisphenol A. etc.), can be rapidly determined, not by a conventional time-consuming and tedious enzyme assay, but by an alternative interferometric biosensor. Heavily boron-doped porous silicon for application as an interferometer, was fabricated by etching to form a Fabry-Perot fringe pattern, which caused a change in the refractive index of the medium including ${\beta}$-galactosidase. In order to enhance the immobilization of the porous silicon surface, a calyx crown derivative (ProLinker A) was applied, instead of a conventional biomolecular affinity method using biotin. This resulted in a denser linked formation. The change in the effective optical thickness versus ${\beta}$-galactosidase activity, showed a linear increase up to a concentration of 150 unit ${\beta}$-galactosidase/mL, unlike the sigmoidal increase pattern observed with the biotin.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.59.2-59.2
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• 2015

We present the results of simultaneous observations of the H2O and SiO masers emitted from the circumstellar envelopes of the late-type stars. These observations have been carried out at the K and Q bands using KVN since 2014 August and were scheduled to test the feasibility of multi-frequency phase referencing analysis on the maser lines. In order to increase the accuracy of group delay solution in the fringe search on the continuum source, the IF channels were randomly distributed within the available bandwidth of 500 MHz in each band. The positions of all maser spots are relatively described with respect to the position of the reference continuum source through the source frequency phase referencing technique, and this provides the astrometric position accuracy. Therefore, the relative locations of the H2O maser spots with respect to the SiO maser spots are determined from our observations, and the capability of the simultaneous multi-band observation of KVN is proved to be powerful to study the maser pumping mechanism around the late-type stars.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.8
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• pp.739-746
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• 2005

When we design a binary phase holographic optical low-pass filter (HOLF), the phase difference is generally set to be $\pi$ to optimize the diffraction efficiency. However, the phase difference of real HOLF mostly deviate from $\pi$ by the error in the fabrication process. The deviation causes the (0,0)-th order diffracted beam to increase, which results In raising the diffraction efficiency. To study the effects of the phase error on the performance of HOLF, we calculated the MTF of HOLF for various phase differences. The results show that the phase error of 10 $\%$ makes little change in the filtering characteristics of HOLF. Considering the filtering by lens and CCD, the effects of the phase error becomes much smaller. To confirm it experimentally, we fabricated HOLFs for various phase differences. After installing it in a digital camera, we take picture of test targets and observe the Moire fringes and the resolution. The results agree with our prediction.

• Journal of Korean Society of Transportation
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• v.5 no.2
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• pp.81-95
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• 1987

In line with the continued growth of car ownership, the traffic problems in central area of metropoles such as Seoul would become increasingly degraded. comparing with most western cities, the problems in Seoul are characterized by the improportionately high rates of intersection delay, station congestion, traffic accidents caused by weaving conflicts and pedestrian congestion. It is caused by the lack of flexibility I street network, which is prerequisite for upholding the efficacy of traffic management and control, resulted from the simplicity of network graph in terms of connectivity, street density and distribution by width. This pattern has been resulted from the prolonged policy pursuing the street-widening of the nagging bottleneck in such a short period since the 1950s, comparing that most western cities had undergone over several centuries an age of horse-and-vehicle transportation. In order to improve the expected traffic problems in central area over the coming periods of motorization, it is imperative to restructure the street network in Central Seoul so that the efficacy of traffic management and control may be operative. Based upon the long-range planning the street network should be restructured by stages so that cenral traffic may be controled by one-way operation and most through-traffic be detoured around fringe area.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.10
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• pp.84-91
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• 2008

Due to the complexity of the engineering problems, it is difficult to obtain directly the stress field around the crack tip by theoretical derivation. In the paper, the hybrid method is employed to calculate full-field stress around the crack tip in uni-axially leaded finite width tensile plate, using the displacement data of given points calculated by finite element method as input data. The method uses complex variable formulations involving conformal mappings and analytical continuity. In order to accurately compare calculated fringes with experimental ones, both actual and reconstructed photoelastic fringe patterns are two times multiplied and sharpened by digital image processing. Reconstructed fringes by hybrid method are quite comparable to actual fringes. The experimental results indicate that Mode I stress intensity factor analyzed by the hybrid method are accurate within a few percent compared with ones obtained by empirical equation and finite element analysis.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.2
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• pp.11-16
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• 2001

The polariscope to measure :he stress in lens was made up quarter-wave plate polarizer and we analyzed two components of light's wave $E_1$ and $E_2$ following the steps. It is clear that the principal-stress difference ${\sigma}_1-{\sigma}_2$ can be determined in 2-D model if fringe order N is measured each point in sample moreover. the optical axes of sample coincide with the principal-stress directions. The birefringence acted to a light wave and a phase retardation were in proportioned to the principal-stressed difference (${\sigma}_1-{\sigma}_2$) and the intensity of final light wave was proportioned to $sin^2({\Delta}/2)$, when ${\Delta}/2=n^{\pi}$ (n=0, 1, 2, ...) and the extinction occurs. As a experimental result, the extinction band shifted owing to a magnitude of lens' external stress.