• Korean Journal of Heritage: History & Science
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• v.42 no.1
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• pp.144-157
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• 2009

Nondestructive methods to check the vitality of trees and to find out internal decay of old-giant trees include the use of electrical resistance, ultrasound transmission time, microdrilling, and infrared thermography etc. Among these, ultrasound transmission offers some advantages compared to others such as it is an entirely nondestructive detection method and it can be applied to very big trees. However, the ultrasound equipment is comparatively expensive and not broadly spread yet. On the other hand, Shigometer is versatile to be applied to check vitality of the tree and find out internal decay. Electrical conductivity of plant tissues is a very useful characteristics to determine the vitality and internal decay of trees. Electrical resistance of cambial area tells about the vitality of a tree and electrical resistance of heartwood reveals discoloration or decay of it. For determination of the vitality of the tree, the standard equation for calibration of measured electrical resistances should be developed by measuring and analyzing electrical resistance from at least 30-40 trees of the same species with that tree. All the factors, especially tree species, diameter of the stem, and temperature, which can altered the electrical resistance of trees, should be taken into consideration in the development of the equation. If the standard equation is developed for old-giant trees that we should conserve, it will be very useful. In addition, periodical and continued measuring of a certain tree will help to determine the condition of the tree by comparing the measurement with accumulated data of the tree. Measuring electrical resistance of wood might not require the standard equation. But it also needs to check electrical resistance of sound wood of the same tree species. If the stems that should be examined is thicker than 40cm, it is better to use the ultrasound measurement combined to Shigometer.

• Korean Journal of Heritage: History & Science
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• v.41 no.1
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• pp.109-125
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• 2008

Recently, there has been an increase in excavation studies of wood pagodas from the Three Kingdoms and Unified Shilla periods and new data related to wood pagoda erection are being found bringing about progress in research on this field. In other words, studies on wooden pagodas in Korea were composed mainly of flat, axis construction techniques and sarijangeomgu, but by acquiring new data, it has now become possible to study not only the stylobate construction procedure and transition, but also studies on restoring wooden pagodas. Furthermore, pagoda sites similar to this were found in China and Japan as well, making it possible to make comparative studies among ancient wooden pagodas possible. In this paper, the main remains were set as Baekjae wooden pagodas, which were the most frequently studied and among the wooden pagodas, the simcho (central base stone) and sarira housing locations. In result, simcho can be found changing its position from underground ${\rightarrow}$ halfway underground ${\rightarrow}$ above ground. Baekjae wooden pagodas up until the mid sixth century located at Neungsan-ri saji (AD 567) and Wangheungsaji (AD 577) had its simcho located underground and later it was constructed halfway underground and then above ground. It was confirmed that in the 7th century, it became customary to place above ground as seen in the Jaeseoksaji (AD639) and Hwangnyongsaji (AD645) wooden pagoda sites. The sarira was usually located on the south side of the simcho, but gradually changed to the center. In particular, sarira were combined in the simcho in the mid sixth century at the Wangheungsaji. This is approximately 11 years earlier than the Bijosa (AD 588) simcho found in Japan and this was not found even in the simcho of wooden pagodas in Yeongnyeongsa (AD 516) and Jopaengseong temple (AD 535~561) of China showing that the Wangheungsaji simcho was the earliest of its kind.

• Korean Journal of Heritage: History & Science
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• v.46 no.3
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• pp.172-193
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• 2013

This study examines the production techniques and raw materials shown in the Korean dried-lacquer statues of Buddha through a careful observation of the Seated Dried-lacquer Bodhisattva Statue from the late Goryeo Dynasty which is currently possessed by Okura Museum of Art in Tokyo. As a method of study, the X-ray data and the results from a field survey were combined to analyze the production techniques and the characteristics of raw materials. Based on this analysis, a hypothesis was established on the production process and verified through a reenactment of the actual production process. Then, the characteristics of the techniques applied to each process and the raw materials were recorded in detail. Specifically, the dried lacquer techniques and the raw materials were estimated based on the results of naked-eye observation in comparison with the literature, especially the records of "Xiu Shi Lu" written by Huang Cheng of the Ming Dynasty which is considered as 'the textbook of lacquer techniques.' The raw materials used in the production of the traditional Korean lacquerware inlaid with mother-of-pearl were also referenced. As a result, it was found that the features of production techniques and the raw materials found in the Statue at Okura Museum of Art have many similarities with those of the Seated Dried-lacquer Statue of Lohan (Arhat) from Yuanfu 2 Nian Ming (1098) of the Song Dynasty which is currently at the Honolulu Museum of Art. In particular, the similarities include that the interior of the statue being vacant because the clay and the wood core were not replaced after being removed from the prototype, that the complete form was made in the clay forming stage to apply the lacquer with baste fiber fabric, that the clay and the wood core were removed through the bottom of the statue, and that the modeling stage was omitted and the final coat over the statue is very thin. Additionally, decorating with ornaments like Bobal and Youngrak made of plastic material was a technique widely popular in the Song Dynasty, suggesting that the Seated Dried-lacquer Bodhisattva Statue in Okura Museum of Art was greatly affected by the production techniques of the Dried-lacquer Buddha Statue from the Song Dynasty. There is no precise record on the origin and history of the Korean Dried-lacquer Buddha Statues and the number of existing works is also very limited. Even the records in "Xuanhe Fengshi Gaoli Tujing" that tells us about the origin of the Dried-lacquer Buddha Statue from the Yuan Feng Period (1078~1085) do not indicate the time of transmission. It is also difficult to trace the clear route of transmission of production techniques through existing Dried-lacquer Buddha Statues. Fortunately, this study could at least reveal that the existing Dried-lacquer Buddha Statues of Korea, including the one at Okura Museum of Art, have applied the production techniques rather differently from those used in the production of Japanese Datsukatsu Dried-lacquer Buddha Statues that have been known as the standard rule in making dried-lacquer statues of Buddha for a long time.

• Korean Journal of Heritage: History & Science
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• v.45 no.1
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• pp.16-33
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• 2012

Maehwa blossom(梅花) has been favoured in literary and artistic works in the East Asia as one of representing symbols of virtuous men's character. Maehwaseookdo(梅花書屋圖) is one of major forms of painting. This paper starts from the birth of Maehwaseookdo since it aims to examine the following points: its structural origin of the Gurimaehwachonsado(九里梅花村舍圖) style; how this style was distributed in Korea; process and features of Maegamdo(梅龕圖). The current academic world admits Maehwaseookdo is originated from an ancient story of Lim Po(林逋). Even though Maehwaseookdo and Lim Po story can be linked to a meaning of schoarly hermitage, ways to structure works are hard to compare paintings based on Lim Po story. While paintings related to Limpo story such as Banghakdo(放鶴圖) and Gwanmaedo(觀梅圖) depict a scholar(s) and a few Maehwa trees with cranes, Maehwaseookdo presents scholarly hermitage with a lot of Maehwa trees which encircle a house building. As other paintings related to Maehwa blossom were widely painted since the nationwide popularity of the theme of Maehwa, Maehwaseookdo was not drown throughout the whole period of time. Since Goryeo, Maehwa paintings including Sehansamu(歲寒三友), ordinary Maehwado as one of the Four Gentlemen's plants, and Tammaedo(探梅圖) which was based on ancient anecdote of Maeng Hoyeon. Maehwaseookdo, however, was created exclusively in the 19th century. In China a similar feature took place much earlier period which was in the 17th century. Accordingly we can assume that these patterns which paintings in particular styles were generated by particular cultural phenomena. The reason why Joseon's Maehwaseookdo works were painted exclusively in the 19th century was that Kim Jeonghee's party and Sin wi had acquaintanceship with Jang Sim(張深) who got work orders for Oh Sungyang(吳嵩梁). In these corresponding activities, two types of Maehwa paintings were exchanged. In China, scholars usually drew paintings in the type of Gurimaehwachonsado(九里梅花村舍圖) depicting scenic views of Guriju(九里洲) which was riverside area under the Mt. Buchun(富春山). This place surrounded by thousands and hundreds of Maehwa trees was where Oh Sungyang(吳嵩梁) was about to retire to hermitage in. In this repect, Joseon scholars painted Maegamdo(梅龕圖) depicting a scene of a shrine with Oh Sungyang(吳嵩梁)'s poetry books surrounded by Maehwa trees for paying tribute to the wall of Maehwa trees(Maebyeok(梅癖)). This seems to adapt the format of 'Manmae(萬梅)' which appeared in the type of Gurimaehwachonsado. One of the representing works of this, is painted or supervised by Sinwi. Paintings in two types with respective meanings were combined by which was estimated to be painted by Sin Wi, then it became a structural base of by Jang Sim(張深) This type of Maegamdo brought the popularity of Maewhoseookdo which once had another name of 'Manmaeseookdo(萬梅書屋圖)' by a group of scholars such as Jo Heeyong, in the 19th century. All things considered, this paper can be a sort of precedent phrase to find out the birth of Manmaeseookdo which was very popular in the late 19th century.

• Korean Journal of Heritage: History & Science
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• v.51 no.4
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• pp.66-83
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• 2018

This article focuses how the materials of hatstrings of the 19th to 20th century gat, the Korean top hat for men among the collections of National Folk Museum of Korea, was transformed after port opening treaties with overseas since 1876. As a result of analyzing the materials of the hatstrings, amber, tortoiseshell, wood and bamboo as the traditional materials were used, and ivory, glass (soda glass, lead glass, alkali mixed glass) and plastics (cellulose nitrate, phenol-formaldehyde, polystyrene, acryl) were newly used for the hatstrings. Bamboo, wood and amber were the most frequently used materials. Bamboo was mainly used for the pipe of hatstring and were combined with beads and central decorations of other materials. This shows the trend of bamboo hatstring according to the simplification of the clothing and the culture by Regent Heungseon Daewongun. Ambers were used in the central decorations and beads and the origin of ambers was baltic amber just like the amber relics found in Korea. Compositions of glass were soda glass and alkali mixed glass which were excavated or handed down in Korea from ancient times to Joseon dynasty. But in the case of lead glass, Na2O was detected and it is considered to be a new type lead glass for crafts which came from overseas after port opening since 1876 because it showed the characteristic that it deviates from the lead glass component found in Korea. Plastics such as cellulose nitrate and phenol-formaldehyde were used as new synthetic materials to replace traditional materials such as tortoiseshell, amber, and coral as in the West. Cracks, crazing, crumbly and yellowing of cellulose nitrate of hatstrings were observed by deterioration. The survey of the materials of the 19th to 20th century hatstrings among the collections of National Folk Museum of Korea showed that the introduction of new materials such as glass and plastics were used to replace natural materials such as tortoiseshell and amber along with the use of traditional materials after port opening since 1876.

• Korean Journal of Heritage: History & Science
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• v.47 no.4
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• pp.22-47
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• 2014

This study was to understand the basic principles of the East Asian wooden structure system research and analysis. The Korea and China ancient architecture internal structure research that the combination of girders and crossbeams position. The ancient wooden structures of eastern Asian countries, Korea and China are not much different from each other in the principles of the wooden architecture structure, combining pillars, purlins and crossbeams. However, it seems that age-division, local-division, national-division differs in detail techniques. China ancient wooden structures combination of purlin and crossbeam, and So-seul Timber(Chinese name: Chashou叉手, Tuojiao 托脚) seems to show differences according to the age of the fulcrum position, detailed approach is also different according to various historical dynasty. Before in the 15th century, Purlin and Crossbeam are coupled to each other, but since the 15th century, seems to have developed a technique combined with each other Girder and Crossbeam and to prevent buckling of the Crossbeam cross-sectional area increased dramatically. For Tuojiao in China Tang-Wudai dynasty(A.D. 618~979), can see that saw the top position Girder and Tuojiao no direct coupling, can be seen as maintaining the safety of the material than the material of the inner wooden structures prevent buckling of the purlin. Korea ancient wooden structures of Goryeo dynasty(A.D. 918~1391), So-seul Timber(Chinese name Tuojiao) why do not to use the fashion? To use Purlin Lower backing material techniques to prevent buckling is a popular trend to stable can be thought of as a preferred way to maintain. I think that with universality beyond the local-division, national-division and the two countries since the 15th century of Korea and China ancient wooden structures detailed mechanism for the purlin buckling. In middle-late Chosen dynasty, The effect of Deotgeolyi- techniques and fleeting beams reduce the purlin buckling that reduces the load transmitted from purlin and crossbeam of how to reduce the load on the roof portion of the architecture fleeting beams used, which of craftsmanship of the Chosen Dynasty building can be referred to as another technique for preventing buckling purlin. This Korea and China ancient architecture purlin beam structure and material So-seul Timber study. Seems to be able to provide a basic research study to restore and designed the old wooden architectures.

• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.573-579
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• 2019

The purpose of this study is predicted easily the entrance surface dose (ESD) in chest digital radiography. We used two detector type such as flat-panel detector (FP) and IP (Imaging plate detector). ESD was measured at each exposure condition combined tube voltage with tube current using dosimeter, after attaching on human phantom, it was repeated 3 times. Phantom images were evaluated independently by three chest radiologists after blinding image. Dose-area product (DAP) or exposure index (EI) was checked by Digital Imaging and Communications in Medicine (DICOM) header on phantom images. Statistical analysis was performed by the linear regression using SPSS ver. 19.0. ESD was significant difference between FP and IP($85.7{\mu}Gy$ vs. $124.6{\mu}Gy$, p=0.017). ESD was positively correlated with image quality in FP as well as IP. In FP, adjusted R square was 0.978 (97.8%) and linear regression model was $ESD=0.407+68.810{\times}DAP$. DAP was 4.781 by calculating the $DAP=0.021+0.014{\times}340{\mu}Gy$. In IP, adjusted R square was 0.645 (64.5%) and linear regression model was $ESD=-63.339+0.188{\times}EI$. EI was 1748.97 by calculating the $EI=565.431+3.481{\times}340{\mu}Gy$. In chest digital radiography, the ESD can be easily predicted by the DICOM header information.

• Korean Journal of Plant Taxonomy
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• v.49 no.3
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• pp.224-239
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• 2019

Species identification for the Korean tribe Desmodieae was conducted using the DNA barcoding genes rbcL, matK (from chloroplast DNA) and ITS (from nuclear ribosomal DNA). A total of 25 taxa (n = 75) in five genera were sequenced, and neighbor-joining trees were constructed using different combinations of DNA barcodes. When comparing these phylogenetic trees, a tree with all loci combined (rbcL + matK + ITS) showed the highest rate of identification success (72%). On this tree, two subtribes and five genera within the tribe were supported as monophyletic. In the Desmodiinae clade, Desmodium and Hylodesmum were more closely related to each other than to Ohwia. In the Hylodesmum clade, H. oldhamii was found to be a sister to H. podocarpum complex, and all taxa within the complex were identified successfully. Subsp. fallax, regarded as a variety of subsp. oxyphyllum, is closely clustered with subsp. podocarpum. Although var. mandshuricum has been regarded as a synonym of var. oxyphyllum, this taxon is supported as a distinct variety. For the Lespedezinae clade, all species of Kummerowia were monophyletic, while nine of 16 Lespedeza taxa were identified successfully. In particular, the resolution of Macrolespedeza (28.5%) was lower than that of Junceae (77.8%). Among the Lespedeza taxa, L. cuneata was distinguishable from L. lichiyuniae, despite morphological similarities. It has been suggested that both L. maritima and L. inschanica are hybrids. The former is thought to be an independent species. While it is difficult to determine whether the latter originated via hybridization, this study showed that it is closely related to L. juncea.

• Journal of Intelligence and Information Systems
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• v.25 no.3
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• pp.1-17
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• 2019

Because stock price forecasting is an important issue both academically and practically, research in stock price prediction has been actively conducted. The stock price forecasting research is classified into using structured data and using unstructured data. With structured data such as historical stock price and financial statements, past studies usually used technical analysis approach and fundamental analysis. In the big data era, the amount of information has rapidly increased, and the artificial intelligence methodology that can find meaning by quantifying string information, which is an unstructured data that takes up a large amount of information, has developed rapidly. With these developments, many attempts with unstructured data are being made to predict stock prices through online news by applying text mining to stock price forecasts. The stock price prediction methodology adopted in many papers is to forecast stock prices with the news of the target companies to be forecasted. However, according to previous research, not only news of a target company affects its stock price, but news of companies that are related to the company can also affect the stock price. However, finding a highly relevant company is not easy because of the market-wide impact and random signs. Thus, existing studies have found highly relevant companies based primarily on pre-determined international industry classification standards. However, according to recent research, global industry classification standard has different homogeneity within the sectors, and it leads to a limitation that forecasting stock prices by taking them all together without considering only relevant companies can adversely affect predictive performance. To overcome the limitation, we first used random matrix theory with text mining for stock prediction. Wherever the dimension of data is large, the classical limit theorems are no longer suitable, because the statistical efficiency will be reduced. Therefore, a simple correlation analysis in the financial market does not mean the true correlation. To solve the issue, we adopt random matrix theory, which is mainly used in econophysics, to remove market-wide effects and random signals and find a true correlation between companies. With the true correlation, we perform cluster analysis to find relevant companies. Also, based on the clustering analysis, we used multiple kernel learning algorithm, which is an ensemble of support vector machine to incorporate the effects of the target firm and its relevant firms simultaneously. Each kernel was assigned to predict stock prices with features of financial news of the target firm and its relevant firms. The results of this study are as follows. The results of this paper are as follows. (1) Following the existing research flow, we confirmed that it is an effective way to forecast stock prices using news from relevant companies. (2) When looking for a relevant company, looking for it in the wrong way can lower AI prediction performance. (3) The proposed approach with random matrix theory shows better performance than previous studies if cluster analysis is performed based on the true correlation by removing market-wide effects and random signals. The contribution of this study is as follows. First, this study shows that random matrix theory, which is used mainly in economic physics, can be combined with artificial intelligence to produce good methodologies. This suggests that it is important not only to develop AI algorithms but also to adopt physics theory. This extends the existing research that presented the methodology by integrating artificial intelligence with complex system theory through transfer entropy. Second, this study stressed that finding the right companies in the stock market is an important issue. This suggests that it is not only important to study artificial intelligence algorithms, but how to theoretically adjust the input values. Third, we confirmed that firms classified as Global Industrial Classification Standard (GICS) might have low relevance and suggested it is necessary to theoretically define the relevance rather than simply finding it in the GICS.

• Korean Journal of Heritage: History & Science
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• v.39
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• pp.219-242
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• 2006

Quantitative analysis and provenance interpretation of the raw materials for the jade (amazonite) excavated from the Asan Sijeonri site were studied. Geology of the Sijeonri site composed mainly of Precambrian metasedimentary rocks and the alluvium ranges extensively. In the site, amazonite jade was excavated in the Bronze Age No. 4 circular-shaped resident site. The jade has a comma-shaped and shows light green color with so much cracks. The jade is silicate mineral of columnar habits that is shown white streak, and has fine cleavages with vitreous luster. As the analytical results, this jade was identified as a feldspar-group mineral gemologically called amazonite that is mineralogically microcline formed to intergrowth of albite and orthoclase. Internal textures of the amazonite present Na-end member of albite coexisting with K-end member of orthoclase that are replaced each other along the cleavages and twin planes with several ${\mu}m$ scales. Therefore, the amazonite is one mineral phase combined with albite and orthoclase by substitution of $Na_2O$ and $K_2O$, respectively. The Danyang are is an unique producing site of amazonite in South Korea, and Gongju Janggimyeon was known as microcline provenance to the utmost area from the Sijeonri site. In the marginal area of southern coast in Korean Peninsula, Bronze Age amazonite has been excavated in several sites, where original provenance of the raw amazonite is not identified. The Sijeonri site does not show any facilities of producing and processing traces for amazonite jade. Also, only one jade was collected in the Sijeonri site. Therefore, there is not possibility that the provenance of raw jade is the Sijeonri area. To explain original provenance of the amazonite jade, migration path, manufacturing process and archaeological interpretation are required.