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Some books were printed using metal type and woodblocks in the Goryeo and Joseon dynasties. In some cases, there are postscripts that record the printing method, printing period, and the background that led to the printing. However, it is difficult to accurately determine the printing dates based solely on that information. When there are several versions of the same old book, it is possible to obtain evidence that can provide clues to determine the printing method and date of each version by image comparison and analysis between versions. In this study, images of six very similar versions of Jeungdoga Scripts (南明泉和尙頌證道歌) estimated to have been printed with metal type and woodblocks between the 13th and 16th centuries were compared and analyzed. The printing method, sequence, and date were estimated. By quantifying and comparing the inked areas of randomly selected characters and corresponding characters in identical locations of different versions, the increase in stroke thickness and printing area in recarved versions was confirmed. Deformation and engraving errors in several characters were found in later versions. Of the six versions, it was concluded that the Gongin version (空印本) was printed in early September 1239 with metal type, and is the earliest version. The other five versions were printed after being engraved with woodblocks in the following order: Banyasa Temple version (般若寺本), Daegu version (大邱本) in 1472, Samseong version (三省本), Jongno Library (鍾路圖書館本) in 1526, and th e National Central Library version (國立中央圖書館本).

To understand the process of publication and distribution of ancient Korean novels under the Joseon dynasty and Japanese occupation, collecting information on the publication of various printed materials and estimating their publication date through various methods is extremely important. In this study, the characteristics and differences that appeared in the woodblock printing process were investigated using image comparison among editions of the Honggildongjeon (Tale of Honggildong) of Wanpanbon (完板本) (published in the Jeonju region) with other commercial editions of the ancient Korean novels. Additionally, the publication year of each edition was estimated. Printed images of different versions were compared with those of a recently discovered original series version and the changes in the process of carving replacement woodblocks were investigated and summarized. Various phenomena, such as differences in fonts, borderline shapes and integrity of printed characters, appearing in woodblock prints provided useful information for determining chronological relationships between the prints and estimating the approximate publication year for each edition. The various characteristics of woodblock printing obtained through this study are expected to serve as a reference for estimating the relationship between the printing method and the approximate publication date of old books and paper-based printed historical records.

Underwater photographing and image recording are essential for pre-excavation survey and during excavation in underwater archaeology. Unlike photographing on land, all underwater images suffer various quality degradations such as shape distortions, color shift, blur, low contrast, high noise levels and so on. Outcome is very often heavily photographing equipment and photographer dependent. Excavation schedule, weather conditions, and water conditions can put burdens on divers. Usable images are very limited compared to the efforts. In underwater archaeological study in very turbid water such as in the Yellow Sea (between mainland China and the Korean peninsula), underwater photographing is very challenging. In this study, off-site image distortion and color compensation techniques using an image processing/analysis software is investigated as an alternative image quality enhancement method. As sample images, photographs taken during the excavation of 800-year-old Taean Mado Shipwrecks in the Yellow Sea in 2008-2010 were mainly used. Significant enhancement in distortion and color compensation of archived images were obtained by simple post image processing using image processing/analysis software (PicMan) customized for given view ports, lenses and cameras with and without optical axis offsets. Post image processing is found to be very effective in distortion and color compensation of both recent and archived images from various photographing equipment models and configurations. Merits and demerit of in-situ, distortion and color compensated photographing with sophisticated equipment and conventional photographing equipment, which requires post image processing, are compared.

Colour consistency is an important consideration when selecting pigments used on works of art. In this study, we analyse the colour difference between two sets of synthetic blue glass pigments acquired at least 8 years apart from the same manufacturer in Japan. The old pigment set (unused, dry powder with four different grain sizes) appears faded compared to the new set. These pigments are made available for artistic use, commonly in Nihonga or Japanese paintings. Raman spectroscopy and SEM-EDS results characterize these pigments as cobalt aluminate spinels dissolved in leaded glaze, a special class of complex coloured inorganic pigments that is not well-understood in the field of conservation. Colour difference between the old and new pigments with four different grain sizes were quantified by analysing photomicrographs with image analysis software. Blue pigments with coarse and extremely fine grains showed significant colour change compared to pigments with medium and fine grain sizes. The high occurrence of crystallites in the finer grains give a final colour that is bluer and lighter. Possible causes for the colour difference including manufacturing methods and storage environment are discussed.

Photographic images of the Samseong-version (三省本: Korea’s Treasure No. 758-1) and the Gongin-version (空印本: Korea’s Treasure No. 758-2) of Nammyeongcheon Hwasangsong Jeungdoga (南明泉和尙頌證道歌: Nanmingquan Song Zhengdaoge) were compared and analyzed to investigate the differences between the two versions. According to a report in 2012 at the time of the designation of the Gongin-version as Korea’s treasure, both versions were printed from the same woodblocks. The Gongin-version is presumed to be a later print than the Samseong-version. The two versions are very similar in format and shape of border lines and characters. It is difficult to determine the differences with the naked eye, even for experts. In this study, based on the printing characteristics observed from each version through image analysis, useful evidence to determine whether it was printed using the same or different woodblocks and the order of printing was collected. As a result of careful image comparison and analysis, we concluded that the Samseong- and the Gongin-version were printed from different woodblocks, or possibly different typesetting. It was difficult to agree with the content of the report that the Gongin-version was a later print than the Samseong-version. In addition, it was noted that the Gongin-version print has characteristics quite different from the typical characteristics of woodblock printing seen in the Samseong-version. Additional investigations and follow-up studies on the printing technology used for Gongin-version print and the timing of printing are recommended.

The history of printing technology in Korea is studied by investigating existing ancient documents and records and comparing accumulated data and knowledge. Cultural property research requires non-destructive testing and observation with the naked eye or aided by a microscope. Researchers’ experience and knowledge are required even though they cannot guarantee the outcome. For ancient documents and records that are presumed to consist of woodblock printing, wood type printing, metal type printing, or their combinations, each researcher draws various opinions and conclusions. This often causes confusion and divides the opinions of ordinary citizens and field specialists. Among them, the criteria for judging ancient documents or books printed using woodblock and metal movable material are ambiguous. Academic research on the development history of printing technology in ancient Korea has been stagnant, and conflicts among researchers have also erupted. Involvement of national investigative agencies not specialized in cultural properties has exacerbated the situation. In this study, we investigated printing characteristics that are likely to serve as more objective judgment criteria by quantitatively analyzing the experiments of retrieving several sheets of Korean paper (Hanji) using a replicated Hunminjeongeum (訓民正音) woodblock and quantitatively analyzing the images of the printed papers. In addition, the validity and questions for the typical phenomena presented as a method for distinguishing between woodblock and metal print are reviewed. We investigated the possibility of developing new objective judgement criteria through quantitative analysis using image analysis and investigating the printing characteristics of Korean paper through a reproduction experiment of woodblock printing.

Gwanghwamun Gate of Gyeongbokgung Palace was dismantled and relocated during the Japanese colonial period, destroyed during the Korean War, reconstructed with reinforced concrete in 1968, and finally erected at its present location in 2010. A pair of Haechi statues located in front of Gwanghwamun was dismantled and relocated several times, and the statues have yet to be returned precisely to their original positions. This study assesses the historical accuracy of their current placement under the Gwanghwamun Square Restructuring Project of the Seoul Metropolitan Government and the Cultural Heritage Administration based on archival photos from the early 1900s, and proposes a method to estimate the original positions of the Haechi through image analysis of contemporary photographs and recent digital camera photos. We estimated the original position of the Haechi before the Japanese colonial period by identifying the shooting location of the archival photo and reproducing contemporary photographs by calculating the angle and distance to the Haechi from the shooting location. The leftmost and rightmost Haechi were originally located about 9.6 m to the east and 7.4 m to the north and about 1.9 m to the west and 8.0 m to the north, respectively, of their current location indicators. As the first attempt to determine the original location of a building and its accessories using archival photos, this study launches a new scientific methodology for the restoration of cultural properties.

Underwater archaeology relies heavily on photography and video image recording during surveillances and excavations like ordinary archaeological studies on land. All underwater images suffer poor image quality and distortions due to poor visibility, low contrast and blur, caused by differences in refractive indices of water and air, properties of selected lenses and shapes of viewports. In the Yellow Sea (between mainland China and the Korean peninsula), the visibility underwater is far less than 1 m, typically in the range of 30 cm to 50 cm, on even a clear day, due to very high turbidity. For photographing 1 m x 1 m grids underwater, a very wide view angle (180o) fisheye lens with an 8 mm focal length is intentionally used despite unwanted severe barrel-shaped image distortion, even with a dome port camera housing. It is very difficult to map wide underwater archaeological excavation sites by combining severely distorted images. Development of practical compensation methods for distorted underwater images acquired through the fisheye lens is strongly desired. In this study, the source of image distortion in underwater photography is investigated. We have identified the source of image distortion as the mismatching, in optical axis and focal points, between dome port housing and fisheye lens. A practical image distortion compensation method, using customized image processing software, was explored and verified using archived underwater excavation images for effectiveness in underwater archaeological applications. To minimize unusable area due to severe distortion after distortion compensation, practical underwater photography guidelines are suggested.

In the digital era, large archives of information and Internet accessibility make information search, including image search, easier and affordable, even from remote locations. Information transmission and sharing can be performed instantly, at any moment. In the case of images, there are risks of transmitting and recklessly sharing intentionally modified images. Such modified images can also be transmitted and used as an additional source of information by followers. In this study, historical portraits of Yu Kil-Chun are shown, who was the first Korean student to study in both Japan and the United States. He was an intellectual, writer, politician, and independence activist of Korea’s late Joseon Dynasty. Using image processing software, the portrait images were compared to investigate aging effects and artificial modifications. Statistics of red (R), green (G), blue (B), and L*, a*, and b* values of every pixel in the selected identical areas of the portraits were compared to identify possible causes of variations, including aging effects and artificial modifications. Sepia toning, used in black and white photographs until the 1930s, and modern digital sepia toning can be very confusing owing to their aging effects. The importance of preservation of physical copies and preservation of context (interconnections between data and between documents) is discussed from archiving and conservation science perspectives.

For advanced application specific devices, combinations of Si/Ge, Ge/Si, Si1-xGex/Si are frequently introduced in the device fabrication process. Epitaxy, condensation and annealing processes are commonly used for controlling the Ge content to a desired level. Strain and crystallinity can be affected by a small variation in composition or Ge content, which can result in device performance deterioration or failure. Thus, the composition, strain and crystallinity must be carefully monitored and controlled throughout the manufacturing process. The electrode formation process is also very critical for successful device fabrication. Any spikes and/or electrically active defects near junctions can be fatal to the device yield. Silicidation processes and resulting silicides must be investigated as much as possible using various non-invasive material characterization techniques. In this study, we report the thermal silicidation characteristics of Ni/Si1-xGex with various Ge content under different annealing temperatures in the range of 225oC ~ 400oC in N2 ambient. Thermal silicidation was performed in a stacked hotplate-based SAO-302LP system designed for 300mm wafers. For resulting silicide characterization, measurements of sheet resistance, Raman spectra, X-ray diffraction curves as well as scanning electron microscopy (SEM) observations were performed. We have studied Ge content and annealing temperature dependence on the resulting electrical and crystallographic silicide characteristics. Figure 1 shows 647nm excited Raman spectra and X-ray diffraction (XRD) curves from reference Si, and resulting silicide from Ni/Si0.75Ge0.25 before and after annealing under at 235oC, 310oC and 400oC. Raman spectra and sheet resistance measurements showed silicide formation and silicide layer thickening with increasing annealing temperature. XRD curves clearly indicated the change of crystalline phase of resulting silicide with annealing temperature increase. Various aspects of thermal silicidation and its characterization will be discussed at the conference. Figure 1

Vanadium doped semi-insulating (SI) 6H-SiC {0001} substrates and their wetting properties were characterized using precisely dispensed de-ionized (DI) water drops. Radius, contact angle, width (chord), height and cap volume of a DI water drop on the SiC surface were quantitatively determined by analyzing sideview images of DI water drop in contact with SI 6H-SiC {0001} substrates using image processing software. The average of ten (10) contact angle measurements showed approximately 4 ° difference between the Si-face (48.48°) and the C-face (44.33º). Contact angle on the Si-face (0001) measured after native oxide removal showed significant decrease of contact angle, from 55° to 25° and recovered over time by room temperature oxidation in air. In contrast, contact angle on the C-face (000-1), measured after native oxide removal, showed significant increase of contact angle, from 40° to 54°, and continue to increase contact angle up to 71° after room temperature oxidation for 24 hours in air. Contact angle is found to be very sensitive to SiC surface polarity and specific surface conditions. Contact angle measurement, using image analysis techniques, can be applied as an in-line identification and surface condition characterization technique for SiC polytypes of specific surface polarities.

There has been a strong and urgent demand to diagnose community transmission-driven coronavirus disease 2019 (COVID-19) after it crossed borders. A large number of rapid and accurate tests and diagnoses are required at drive-through test stations, community clinics and hospitals. Isothermal amplification technology, such as loop-mediated isothermal amplification (LAMP) and recombinase polymerase amplification (RPA), provides excellent alternatives for resource limited test environments. LAMP has been shown to be comparable with polymerase chain reaction (PCR) and can be performed in less than 30 min by non-laboratory staff without ribonucleic acid (RNA) extractions commonly associated with PCR. LAMP tests on assays with SARS-CoV-2 and other pathogenic microorganisms, such as Dengue, Malaria, and Influenza viruses and Helicobacter pylori show color changes allowing test results to be interpreted by the color change of the assays. However, visual inspection of a large number of assays is prone to human error and manual record keeping makes test result tracking for an epidemiologic investigation very difficult and inefficient. The epidemiologic investigation is an essential part of the fight against community transmission-driven viruses. We have developed a very accurate and reliable, human error free, tablet PC-based portable device for colorimetric determination of assays including SARS-CoV-2 and other pathogenic microorganisms.

Colour is a primary characteristic of visual perception and a very important characteristic to describe cultural heritage works in a variety of shapes, sizes and materials. To quantify colours, portable colorimeters are often carried and used for measuring colour of interest. Spatial resolution of colorimeters is manufacturer and model dependent and typically worse than 3 - 10 mm in diameter. The colour measurement has to be done on site at the time of interest. It poses very significant limitations in colorimetric characterization of cultural heritages. In this paper, the possibility of extraction of colour information from digital photographs, scanned images and video files using customized image processing/analysis software (PicMan) was investigated for cultural heritage characterization applications. As colour information extraction examples, a commercial Gouache paint colour card, a digital photograph, a portrait of a Korean scholar of Joseon Dynasty and a severely deteriorated old medical text book before and after restoration were examined. Colour information from various digital images was successfully extracted from points and regions of interest in RGB, HSV, L*a*b*, Munsell colour and hexadecimal colour code formats. The spatial resolution of colour information extraction is as small as a single pixel in a digital image.

Mechanical stress was applied to single side polished and double side polished Si wafers in polypropylene wafer containers for different localized stress levels and durations. Room temperature photoluminescence (RTPL) spectra from Si wafers were measured before and after applying localized mechanical stress. Significant changes (up to 26% increase) in RTPL intensity were measured from areas under different stress levels even 1 year after the fixtures for mechanical stress generation were removed. Significant effects of localized mechanical stress on RTPL intensity variations were measured up to 49 days after the fixture removal. Nearly fully relaxed RTPL signatures for localized mechanical stress were measured 450 days after the fixture removal. RTPL intensity is found to be very sensitive to the externally applied macro-scale mechanical stress of Si wafers and residual (or memorized) internal stress even after removal of fixtures for external mechanical stress generation.

n-type SiC wafers with localized 4H, 6H, and 15 R polytype grains were photographed and their colors were analyzed to find correlations among polytypes, carrier concentration and apparent color. The SiC wafers were photographed and the color information of different colored regions from the photographs was extracted, both for RGB (red, green, and blue) and HSV (hue, saturation, and value) color space formats using image processing software (PicMan). Polytype and carrier concentration of n-type SiC wafers were identified from Raman spectra for correlation with the color analysis results. The carrier concentration of SiC wafers was estimated to be in the range of 2 × 1017 cm−3 to 1 × 1019 cm−3 from a line-shape analysis of measured Raman spectra. The color analysis revealed that there is very strong correlation between polytype and hue value. The carrier concentration strongly affects saturation and value of apparent color. SiC wafers with lower carrier concentration showed higher clarity (lower saturation (or colorless) and higher value (higher transparency)). As the carrier concentration is increased, the wafer becomes translucent (high saturation or colored) and dark or opaque (low value). The polytype and carrier concentration of SiC wafers can conveniently be estimated from their apparent color.

Two-inch diameter 6H-SiC wafers were sliced from a SiC ingot and the wafers were ground and polished using different diamond slurries (1 μm and 0.1 μm in particles size) to investigate their dependence on wetting on surface roughness (Ra) and polarity using precisely dispensed de-ionized (DI) water drops. The Ra of the Si-face (0001) SiC wafer, after grinding and polishing, was 5.6 and 1.6 nm, respectively, as measured by atomic force microscopy (AFM). For C-face (000–1) SiC wafers, the Ra was 7.2 nm after grinding and 3.3 nm after polishing. The average contact angle measurement of the SiC wafers after final polishing showed clear differences between surface polarity; the contact angle for the Si-face (0001) was ~7o greater than that for the C-face (000–1). The difference in contact angles between the Si-face (0001) and the C-face (000–1) tends to increase as the reduction of surface roughness approaches the final stage of polishing. The uniformity of Raman peak intensity in the folded transverse optical phonon band at ~780 cm−1 in scanned areas correlated well with the surface roughness measured by AFM. The contact angle measurement can be used as a convenient surface polarity and surface roughness testing technique for SiC wafers.

To investigate the effect of implantation temperature on the damage to a Si lattice, room temperature photoluminescence (PL) spectra were measured from highly-channeled MeV 11B+ implanted Si wafers with different implant temperatures (25 °C and 450 °C) after annealing at 950 °C for 3 min in N2. Small pieces from the wafers were used for PL characterization. The implanted Si wafer piece at the elevated temperature resulted in higher overall PL intensity under both excitation wavelengths suggesting lesser lattice damage than the Si wafer implanted at room temperature. Unexpectedly large PL intensity variations were observed from PL area mapping of both wafer pieces. In addition, strange behaviors of localized PL intensity variations, with opposite trends between 670 nm and 827 nm excitation PL measurements were observed near the scribe lines and sample number markings on the backside. The PL intensity was increased under 670 nm excitation while it was decreased under 827 nm excitation. Possible reasons for this strange behavior were discussed based on experimental results and analysis. PL measurement is verified to be very sensitive to the surface condition, interface, bulk and backside conditions of the Si. For reliable PL measurement, backside contamination and scratches, such as scribe lines, should be avoided.

Solar panel photovoltaic (PV) systems are widely used in Korea to generate solar energy, which is one of the most promising renewable energy sources. With regard to solar electricity providers and a grid operator, it is critical to accurately predict solar power generation for supply-demand planning in an electrical grid, which directly affects their profit. This prediction is, however, a challenging task because solar power generation is weather dependent and uncontrollable. In this study, a daily prediction model based on the weather forecast information for solar power generation is proposed. In the case of the proposed model, the cloud and temperature data available from the weather forecast information is used to predict the amount of solar radiation as well as a loss adjustment factor to reflect the possible loss of power generation due to the degradation or failure of the PV module. Using the proposed model, solar power generation for the following day can be predicted. The proposed model is embedded into a solar PV monitoring system that is commercially used in Korea, and it is shown to perform better than the existing prediction models.

Silicon near Cu through-silicon vias (TSVs) develops stresses during processing steps, and the local stress of Si around Cu TSVs of sizes ranging from 4 to 8 μm was characterized using micro-Raman spectroscopy as a function of processing steps. Micro-Raman measurements showed that the max stress sum, σ r + σ θ, is size dependent, where the stress sum of 88.7 MPa in the compressive direction was measured in Si for 8 μm sized Cu via, and this max stress sum, σ r + σ θ, decreased to 21 MPa in compression for 4 μm sized Cu via. With the deposition of oxide/nitride overlayers, the stress sum was found to switch sign to 138.9 MPa in the tensile direction for 8 μm sized Cu via after deposition of the SiN overlayers with residual compressive stress caused by ion bombardment. The measured stresses by micro-Raman was used to determine the keep-off-zone that can be used in device design to ensure reliability, and compared against the TCAD simulations results.

Corona discharge-based non-contact capacitance-voltage (C-V) measurement technique has been used for characterization of dielectrics on Si. For corona discharge generation, high voltage is applied to an electrode above dielectrics/Si sample. High voltage electrical discharge and arcing experiments were performed on Si wafers to investigate potential impact (or side effect) on electronic properties of Si wafers. Room temperature photoluminescence (RTPL) spectra from Si samples were measured before and after high voltage direct current (HVDC) discharge and Piezo ignition arcing experiments. Distinctive discharge and arcing footprints were observed in RTPL area maps suggesting modification of electronic properties.

Formation of high integrity junctions with low junction leakage and defects is essential for fabricating high performance devices with advanced node devices. Understanding of implant activation and implant damage recovery mechanisms during annealing process steps is limited. Development of noncontact implant activation and residual damage monitoring techniques would be beneficial.

We newly proposed transparent conductive oxide with diffraction grating structure as an excitation field of surface plasmon resonance working at near-infrared spectral region. We experimentally demonstrated the excitation of SPR using Sn-doped In2O3 films with micro-meter pitched diffraction grating. In this study, we considered the correlation between the grating pitch and the optical reflection spectra. Reflection spectra showed clear polarization properties in infrared spectral region, and the reflection edge has also correlation with the pitch of grating. From these results, the excitation of SPR grating was successfully demonstrated and the wavelength can be tuned by changing the grating pitch in infrared region.

A SiC crystal mixed with 4H-, 6H-, and 15R-SiC polytypes and their wetting properties were characterized using precisely dispensed de-ionized (DI) water drops. Contact angles of a DI water drop on SiC surfaces were quantitatively determined by analyzing the sideview image of a DI water drop in contact with the SiC substrate with mixed polytypes using image analysis software. The contact angle measurements showed that the contact angle for the Si-face (0001) was approximately 4o ∼ 8o greater than that for the C-face (000-1) regardless of polytype. The surface roughness of both Si-face and C-face was measured using atomic force microscopy and confirmed to be nearly identical. Due to the difference in surface energy of polarity of SiC basal planes, the contact angle measured from the Si-face (0001) after native oxide removal showed significant decrease and it recovered over time by room temperature oxidation in air. In contrast, the contact angle measured from the C-face (000-1) after native oxide removal, showed significant decrease and it was maintained, even after room temperature oxidation for 24 h in air. We found that there is correlation between the wetting property of SiC polytypes of 4H-, 6H-, and 15 R and a difference in their surface potential energy corresponding to the hexagonality of each SiC polytype determined by the atomic arrangement.

Thermal silicidation characteristics of Ni/Si1-xGexwith various Ge content was studied under different annealing temperatures in the range of 225 °C ∼ 400 °C in 100% N2ambient. TiN capped Ni/Si1-xGex/Si/SiO2/Si wafers with x values in the range of 0.15 and 0.30 in 0.05 intervals were used. Thermal silicide formation was performed in a stacked hotplate-based annealing system designed for industrial 300 mm wafer fabs. For silicide characterization, measurements of spectral reflectance, sheet resistance, Raman spectra as well as X-ray diffraction curves were performed to investigate changes of optical properties, electrical properties, crystallographic phases during silicide formation. Effects of Ge content and annealing temperature on the electrical and crystallographic properties of the resulting thermal silicides (nickel germanosilicides) were investigated. Reaction mechanisms were discussed based on the characterization results. Multiwavelingth micro-Raman spectroscopy was found to be very promising as a non-contact, in-line silicidation process monitoring technique. For production worthiness verification of the thermal silicidation process, temperature sensitivity curves of sheet resistance, its uniformity and detailed sheet resistance maps were investigated using 8 nm thick Ni films on 300 mm diameter, epitaxial Si0.8Ge0.2/p−-Si wafers without a capping layer. Manufacturability of Ni/Si0.80Ge0.20/Si wafers were also verified using a stacked hotplate-based, nearly isothermal, annealing system.