• Journal of the Microelectronics and Packaging Society
• /
• v.19 no.1
• /
• pp.81-87
• /
• 2012

This paper focuses on three-dimensional measurement system of micro balls on micro Ball-Grid-Array(BGA) packages in-line. Most of visual inspection system still suffers from sophisticate reflection characteristics of micro balls. For accurate shape measurement of them, a specially designed visual sensor system is proposed under the sensing principle of phase shifting moire interferometry. The system consists of a pattern projection system with four projection subsystems and an imaging system. In the projection system, four subsystems have spatially different projection directions to make target objects experience the pattern illuminations with different incident directions. For the phase shifting, each grating pattern of subsystem is regularly moved by PZT actuator. To remove specular noise and shadow area of BGA balls efficiently, a compact multiple-pattern projection and imaging system is implemented and tested. Especially, a sensor fusion algorithm to integrate four information sets, acquired from multiple projections, into one is proposed with the basis of Bayesian sensor fusion theory. To see how the proposed system works, a series of experiments is performed and the results are analyzed in detail.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.28 no.1
• /
• pp.27-36
• /
• 1998

The purpose of this study was to obtain information on the clinical and radiographic features of the fibro-osseous lesions in the jaws. For this study, the author examined and analysed the clinical records and radiographs of 71 cases of 68 patients in fibrous dysplasia, 35 cases of ossifying fibroma and 30 cases of 16 patients of periapical cemental dysplasia diagnosed by clinical and radiographic or histopathological examinations. The obtained results were as followings: L Fibrous dysplasia occurred most frequently in the 2nd decade (30.0％), ossifying fibroma in the 3rd-4th decades, periapical cemental dysplasia in the 4th decade, and all of three lesions showed slight predilection in females. In most cases, chief complaints were painless facial swelling in fibrous dysplasia and ossifying fibroma, and periapical cemental dysplasia was found accidentally in radiographs. 2. Fibrous dysplasia was occurred more frequently in maxilla, ossifying fibroma in mandible and both lesions in premolar-molar area. Periapical cemental dysplasia was occurred most frequently in the mandibular anterior area. The size of fibrous dysplasia was larger than that of ossifying fibroma, and the shape of ossifying fibroma was more round and elliptical than fibrous dysplasia whose was fusiform. 3. Fibrous dysplasia was shown homogeneous radiopaque shadow of 57.6％ and ossifying fibroma & periapical cemental dysplasia were shown mixed appearance of radiolucency and radiopacity shadows at 74.2％, 60.0％, respectively. 4. Fibrous dysplasia was entirely shown poorly defined at 87.7％, but ossifying fibroma & periapical cemental dysplasia were shown well outlined at 60.0％, 70.0％, respectively. 5. Cortical thinning and expansion were observed in fibrous dysplasia and ossifying fibroma, and severe in ossifying fibroma than fibrous dysplasia, and those signs were not seen in periapical cemental dysplasia. Loss of lamina dura was dominant in fibrous dysplasia and root resorption was dominant in ossifying fibroma. Displacement of mandibular canal and the degree of the increase of vertical dimension were alike in both lesions. Displacement of maxillary sinus or nasal cavity, thinning & expansion of the maxillary sinus were dominant in fibrous dysplasia. 6. Polyostotic fibrous dysplasia was occurred at 5.9％, Multiple periapical cemental dysplasia at 43.7％. Occurrence rate in the edentulous area of fibrous dysplasia and ossifying fibroma were 7.0％, 8.6％, respectively.

• Journal of KIISE:Software and Applications
• /
• v.32 no.2
• /
• pp.128-139
• /
• 2005

Moving object boundary is very important for moving object segmentation. But the moving object boundary shows broken boundary We invent a novel space-oriented boundary linking algorithm to link the broken boundary The boundary linking algorithm forms a quadrant around the terminating pixel in the broken boundary and searches forward other terminating pixel to link within a radius. The boundary linking algorithm guarantees shortest distance linking. We also register the background from image sequence. We construct two object masks, one from the result of boundary linking and the other from the registered background, and use these two complementary object masks together for moving object segmentation. We also suppress the moving cast shadow using Roberts gradient operator. The major advantages of the proposed algorithms are more accurate moving object segmentation and the segmentation of the object which has holes in its region using these two object masks. We experiment the algorithms using the standard MPEG-4 test sequences and real video sequence. The proposed algorithms are very efficient and can process QCIF image more than 48 fps and CIF image more than 19 fps using a 2.0GHz Pentium-4 computer.

• The Korean Journal of Archival Studies
• /
• no.39
• /
• pp.229-280
• /
• 2014

This essay focused on the critical review of Korean National Archives System(KNAS) since 1999. We think that KNAS could establish the backbone with basic records law on 1999. It's right. But it is not enough for explaining the full historical growth. there are some factors below the growth. This essay tried to the basic three factors below. That means the the demonstration discourse, archival system practices, and archiving technologies in the contexts of the unique standard by the basic records law. These three factors have been the powerful engine for the take-off of KNAS since 1999. However, the powerful history has shadows of growth. This essay narrated the shadows by the frame of 'counter-destiny'. The most dangerous shadow is the loss of archival cultures because the KNAS has been composed of efficiency mentality. That means that KNAS has no unique archival culture for citizenship. So, this essay tried to talk about 'Post1999' to Archives Community.

• English & American cultural studies
• /
• v.14 no.1
• /
• pp.95-116
• /
• 2014

Paul Auster's The Locked Room, the third novel of The New York Trilogy, has been examined by many critics in terms of anti-detective fiction or postmodernism. However, this paper focuses upon how the author adopts and utilizes some key elements of the traditional detective novel and its literary tradition. Mystery storytelling is one of Auster's literary strategies and the theme of the double is another. For his novel Auster explores the theme of the double as in Poe's "William Wilson." In The Locked Room, the narrator "I" is described as a shadow of his childhood friend Fanshawe. After Fanshawe's disappearance "I" becomes a literary agent for his friend, and becomes a husband of his friend's wife and a father of his friend's child. Searching for information to write a biography of his friend, he realizes that his friend has always been living inside his skull condemned to a mystical solitude. When Fanshawe appears in the narrator's mind as an image of the door of a locked room, the locked room is also a metaphor for the closed consciousness of the narrator. In his strategy of mystery storytelling, Auster employs the quest of detective fiction as well as the irony of Oedipus the King, where the criminal pursued by the king turns out to be himself. The Locked Room starts with the mystery of Fanshawe's disappearance, and as the novel develops, the narrator pursues numerous clues about his biographical subject like a private eye. Ironically, however, he finds that the ghost of Fanshawe has always been with him and that this is inevitable. As the narrator resolves to quit his life as a double, he contrives to name a strange man Fanshawe as if he tries to turn his biographical subject into a fictional character in the same way Fanshawe has controlled the narrator like a character in Fanshawe's novel. Beaten by the fictional Fanshawe and recovering from a near-death experience, the narrator prepares for his final showdown with Fanshawe. The transcendence of his existence as a double is epitomized by his act to tear off the red notebook handed to him by Fanshawe, which confusingly delivers a message that a life is doomed to be a failure. The narrator's act to cut off Fanshawe's influence bespeaks his breaking out of his locked consciousness and a new start for his life with his own identity.

• Anatomy & Biological Anthropology
• /
• v.31 no.4
• /
• pp.133-142
• /
• 2018

3D histology is a imaging system for the 3D structural information of cells or tissues. The synchrotron radiation propagation phase contrast micro-CT has been used in 3D imaging methods. However, the simple phase contrast micro-CT did not give sufficient micro-structural information when the specimen contains soft elements, as is the case with many biomedical tissue samples. The purpose of this study is to develop a new technique to enhance the phase contrast effect for soft tissue imaging. Experiments were performed at the imaging beam lines of Pohang Accelerator Laboratory (PAL). The biomedical tissue samples under frozen state was mounted on a computer-controlled precision stage and rotated in $0.18^{\circ}$ increments through $180^{\circ}$. An X-ray shadow of a specimen was converted into a visual image on the surface of a CdWO4 scintillator that was magnified using a microscopic objective lens(X5 or X20) before being captured with a digital CCD camera. 3-dimensional volume images of the specimen were obtained by applying a filtered back-projection algorithm to the projection images using a software package OCTOPUS. Surface reconstruction and volume segmentation and rendering were performed were performed using Amira software. In this study, We found that synchrotron phase contrast imaging of frozen tissue samples has higher contrast power for soft tissue than that of non-frozen samples. In conclusion, synchrotron radiation propagation phase contrast cryo-microCT imaging offers a promising tool for non-destructive high resolution 3D histology.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.11 no.2
• /
• pp.72-78
• /
• 2009

The demand for rainfall data in gridded digital formats has increased in recent years due to the close linkage between hydrological models and decision support systems using the geographic information system. One of the most widely used tools for digital rainfall mapping is the PRISM (parameter-elevation regressions on independent slopes model) which uses point data (rain gauge stations), a digital elevation model (DEM), and other spatial datasets to generate repeatable estimates of monthly and annual precipitation. In the PRISM, rain gauge stations are assigned with weights that account for other climatically important factors besides elevation, and aspects and the topographic exposure are simulated by dividing the terrain into topographic facets. The size of facet or grid cell resolution is determined by the density of rain gauge stations and a $5{\times}5km$ grid cell is considered as the lowest limit under the situation in Korea. The PRISM algorithms using a 270m DEM for South Korea were implemented in a script language environment (Python) and relevant weights for each 270m grid cell were derived from the monthly data from 432 official rain gauge stations. Weighted monthly precipitation data from at least 5 nearby stations for each grid cell were regressed to the elevation and the selected linear regression equations with the 270m DEM were used to generate a digital precipitation map of South Korea at 270m resolution. Among 1.25 million grid cells, precipitation estimates at 166 cells, where the measurements were made by the Korea Water Corporation rain gauge network, were extracted and the monthly estimation errors were evaluated. An average of 10% reduction in the root mean square error (RMSE) was found for any months with more than 100mm monthly precipitation compared to the RMSE associated with the original 5km PRISM estimates. This modified PRISM may be used for rainfall mapping in rainy season (May to September) at much higher spatial resolution than the original PRISM without losing the data accuracy.

• Korean Journal of Environment and Ecology
• /
• v.32 no.4
• /
• pp.425-439
• /
• 2018

W investigated the environmental factors and inhabiting biota such as macrophytes and zooplankton in 43 sites located on Jeju Island from May and June 2017 to evaluate the spread and ecosystem risk of dotted duckweed (landoltia punctata) which was recently found for the first time in Jeju Island. Dotted duckweeds were found in a total of 18 sites which tended to show low biomass of aquatic macrophyte species other than the dotted duckweed. We conducted a pattern analysis using SOM (Self-Organizing Map), which extracts information through competitive and adaptive properties, to analyze the effect of inhabiting biota on aquatic macrophytes such as the dotted duckweed and environmental factors. The SOM analysis showed that the inhabiting biota such as the zooplankton affected the biomass of aquatic macrophytes than they did the environmental factors. In particular, the biomass of dotted duckweed was positively related to plant-attached species (Alona, Chydorus, and Pleuroxus). Considering that low density of aquatic macrophytes covers the streams and wetlands on Jeju Island because of irregular water source and sharp change of water depth, the dotted duckweeds are likely to play an essential role as the vital habitat for micro-biota including zooplankton in wetlands and streams on Jeju Island. Furthermore, considering that organic matters are utilized as the primary food source in the areas occupied by dotted duckweed, dotted duckweeds have the role of being both habitat and food source. Although the dense growth of dotted duckweed adversely affects growth and development of some aquatic plants due to the shadow effect, it is due to the dominance of floating plants on the water surface should not be regarded as the risk of the dotted duckweed. In conclusion, the dotted duckweeds have spread and settled in most of the water systems on Jeju Island, their impact on inhabiting biota and the aquatic environment was minor. It is necessary to monitor the distribution and spread of dotted duckweeds in the inland areas outside of Jeju Island in the future.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.18 no.4
• /
• pp.233-241
• /
• 2016

Experiments were carried out to quantify the topographic effects on attenuation of sunshine in complex terrain and the results are expected to help convert the coarse resolution sunshine duration information provided by the Korea Meteorological Administration (KMA) into a detailed map reflecting the terrain characteristics of mountainous watershed. Hourly shaded relief images for one year, each pixel consisting of 0 to 255 brightness value, were constructed by applying techniques of shadow modeling and skyline analysis to the 3m resolution digital elevation model for an experimental watershed on the southern slope of Mt. Jiri in Korea. By using a bimetal sunshine recorder, sunshine duration was measured at three points with different terrain conditions in the watershed from May 15, 2015 to May 14, 2016. The brightness values of the 3 corresponding pixel points on the shaded relief map were extracted and regressed to the measured sunshine duration, resulting in a brightness-sunshine duration response curve for a clear day. We devised a method to calibrate this curve equation according to sky condition categorized by cloud amount and used it to derive an empirical model for estimating sunshine duration over a complex terrain. When the performance of this model was compared with a conventional scheme for estimating sunshine duration over a horizontal plane, the estimation bias was improved remarkably and the root mean square error for daily sunshine hour was 1.7hr, which is a reduction by 37% from the conventional method. In order to apply this model to a given area, the clear-sky sunshine duration of each pixel should be produced on hourly intervals first, by driving the curve equation with the hourly shaded relief image of the area. Next, the cloud effect is corrected by 3-hourly 'sky condition' of the KMA digital forecast products. Finally, daily sunshine hour can be obtained by accumulating the hourly sunshine duration. A detailed sunshine duration distribution of 3m horizontal resolution was obtained by applying this procedure to the experimental watershed.

• Korean Journal of Remote Sensing
• /
• v.13 no.2
• /
• pp.99-120
• /
• 1997

Solar radiation is scattered and absorbed atmospheric compositions in the atmosphere before it reaches the surface and, then after reflected at the surface, until it reaches the satellite sensor. Therefore, consideration of the radiative transfer through the atmosphere is essential for the quantitave analysis of the satellite sensed data, specially at shortwave region. This study examined a feasibility of using radiative transfer code for estimating the atmospheric effects on satellite remote sensing data. To do this, the flux simulated by LOWTRAN7 is compared with CAGEX data in shortwave region. The CAGEX (CERES/ARM/GEWEX Experiment) data provides a dataset of (1) atmospheric soundings, aerosol optical depth and albedo, (2) ARM(Aerosol Radiation Measurement) radiation flux measured by pyrgeometers, pyrheliometer and shadow pyranometer and (3) broadband shortwave flux simulated by Fu-Liou's radiative transfer code. To simulate aerosol effect using the radiative transfer model, the aerosol optical characteristics were extracted from observed aerosol column optical depth, Spinhirne's experimental vertical distribution of scattering coefficient and D'Almeida's statistical atmospheric aerosols radiative characteristics. Simulation of LOWTRAN7 are performed on 31 sample of completely clear days. LOWTRAN's result and CAGEX data are compared on upward, downward direct, downward diffuse solar flux at the surface and upward solar flux at the top of the atmosphere(TOA). The standard errors in LOWTRAN7 simulation of the above components are within 5% except for the downward diffuse solar flux at the surface(6.9%). The results show that a large part of error in LOWTRAN7 flux simulation appeared in the diffuse component due to scattering mainly by atmispheric aerosol. For improving the accuracy of radiative transfer simulation by model, there is a need to provide better information about the radiative charateristrics of atmospheric aerosols.