• Title/Summary/Keyword: Chronological Changes

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Age Dating and Paleoenvironmental Changes of the Kunang Cave Paleolithic Site

  • Yum, Jong-Kwon;Lee, Yung-Jo;Kim, Jong-Chan;Kim, In-Chul;Kim, Ju-Yong
    • The Korean Journal of Quaternary Research
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    • v.17 no.2
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    • pp.145-148
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    • 2003
  • The Kunang cave paleolithic site is located at Tanyang [$N37^{\circ}2'$, $128^{\circ}21'E$], Chungbuk Province, which is in the Central part of the Korean peninsula. The cave is developed at 312 amsl in a karstic mountainous area. The South Han River flows across this region and other caves can also be found near the river. The site was discovered in 1986 and excavated 3 times by the Chungbuk National University Museum until now. The cave was wellpreserved from modem human activities until the first discovery. The full length of the cave is estimated to be ca. 140 m. However, a spacious part up to 11 m from the entrance has been excavated. Eight lithological units are divided over the vertical profile at a depth of 5 m. Each unit is deposited in ascending order as follow: mud layer (Unit 9), lower complex (Unit 8) which is composed of angular blocks and fragments with a muddy matrix, lower travertine layer (Unit 7; flowstone), middle complex (Unit 6; cultural layer) which is composed of fragments with a muddy matrix, middle travertine layer (Unit 5; flowstone), yellowish muddy layer (Unit 4), upper complex (Unit 3; cultural layer) which has a similar composition to Unit 8. the upper travertine layer (Unit 2; flowstone), and finally surface soil layer (Unit 1). The most abundant vestiges in the cultural layers are the animal bones. They are small fractured pieces and mostly less than 3 cm in length. About 3,800 bone pieces from 25 animal species have been collected so far, 90 percent of them belonging to young deers. Previous archaeological study of these bone pieces shows thatprehistoric people occupied the cavenot for permanent dwelling but for temporary shelter during their seasonal hunting activity. More extensive studies of these bones together with pollen analysis are in progress to reconstruct the paleoenvironment of this cave. Only a single date (12,500 BP) obtained from a U-Th measurement of the upper travertine layer was previously available. In spite of the importance of the cave stratigraphy, there was no detail chronological investigation to establish the depositional process of the cultural layers and to understand the periodic structure of the cave strata, alternating travertine floor and complex layers. We have measured five 14C age dating (38900+/-1000, 36400+/-900, 40600+/-1600, more than 51000 and 52000 14C BP) using Seoul National University 14C AMS facility, conducted systematic process of the collagen extraction from bone fragments samples. From the result, we estimate that sedimentation rate of the cave earth is constant, and that the travertine layers, Unit 2 and Unit 3, was formed during MIS 5a(ca. 80 kBP) and MIS 5c (ca. 100 kBP) respectively. The Kunang Cave site is located at Yochonli of the region of Danyang in the mid-eastern part of Korea. This region is compased of limestones in which many caves were found and the Nam-han river flows meanderingly. The excavations were carried out three times in 1986, 1988, and 1998.

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Chronological Trends in Practice Pattern of Department of Pediatric Dentistry : 2006 - 2015 (최근 10년간(2006 - 2015) 서울대학교 치과병원 소아치과의 진료 현황에 대한 연구)

  • Seo, Meekyung;Song, Ji-Soo;Shin, Teo Jeon;Hyun, Hong-Keun;Kim, Jung-Wook;Jang, Ki-Taeg;Lee, Sang-Hoon;Kim, Young-Jae
    • Journal of the korean academy of Pediatric Dentistry
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    • v.45 no.2
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    • pp.215-224
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    • 2018
  • The practice pattern of pediatric dentistry has been changing for the last several decades. This change might be influenced by several factors such as development in dental materials and socioeconomic changes. The purpose of this study was to analyze the changing trends of patient distribution and treatment pattern of pediatric dentistry. Patient distribution and practice trends from 2006 to 2015 at the department of pediatric dentistry of Seoul National University Dental Hospital were reviewed. From 2006 to 2015, the proportion of new patient increased from 12.49% to 20.56%. The average age of new patients decreased. In 2006, restorative treatment had highest percentage, followed by preventive treatment, orthodontic treatment, surgical treatment, and pulp treatment. In 2015, preventive treatment had highest percentage, followed by restorative treatment, orthodontic treatment, surgical treatment and pulp treatment Frequency of general anesthesia increased more than 5 times for last 10 years. The proportion of insurance treatment decreased until 2009, and after 2010 it increased steadily.

Chronological observation on intestinal histopathology and intraepithelial Iymphocytes in the intestine of rats infected with Metagonimus yokogawai (요코가와흡충 감염 흰쥐에 있어서 장병변 및 장상피내 림프구 (IEL) 증감에 대한 경시적 관찰)

  • 채종일;윤태영
    • Parasites, Hosts and Diseases
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    • v.32 no.4
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    • pp.215-222
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    • 1994
  • The relationship between the intestinal histopathology and number and position of' intraepithelial Iymphocytes(IEL) was observed chronologically in the small intestine of rats experimentally infected wiH Metagonimw vokogawci. Fifteen Sprague-Dawley rats were orally infected each with 3,000 metacercariae, and 3 were kept uninfected for controls. Three rats each were sacrificed on the day 5, 10, 15, 24 and 70 post-infection (PI) and samples of the small intestine, 5 cm, 10 cm, 20 cia and 70 cm posterior to the pylonls were taken. The samples were processed routinely and stained with Giemsa. The intestinal histopathology was severe during the day 5-15 PI and characterized by villous atrophy, crypt hyperplasia, and decrease of villus/ciypt height ratio. After the day 24 PI, the intestinal lesions showed some tendency of recovery The number of IEL increased at the early stage of infection, but decreased thereafter to a lower level than that of controls, with progression of the pathological changes. Then, the IEL number began to increase again after the day 24 PI. In control rats, the great majority of the IEL were located at the basal region of the epithelium. During the early stage of infection, however, a considerable proportion of IEL was found to have moved to the intermediate or apical region of the epithelium. From the above results, it is suggested that the change of IEL number and position during the course of M. yokogowoi infection should be closely related to the progression and recovery of the intestinal histopathology.

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A Study on the Cultural Exchange of the Weaving Skills and Patterns Witnessed in Geum-textiles between the East and West - from Ancient Times to the Tang Dynasty - (제직기술과 문양을 통해 본 금직물(錦織物)의 동서교류에 관한 연구 - 고대부터 당시대를 중심으로 -)

  • Shin, Hey-Sung
    • Journal of the Korean Society of Costume
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    • v.62 no.4
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    • pp.107-122
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    • 2012
  • The purpose of this study is to investigate the changes and developments that occurred as a result of the exchanges of gyeong-geum(經錦), a warp-faced compound weave of East Asia, and wie-geum(緯錦), a weft-faced compound weave of West Asia. In order to maximize the efficiency of this research, topics were narrowed down to the weaving skills and patterns, and the period was limited to the Tang dynasty. The systematic characteristics and differences of gyeong-geum and wie-geum were compared and contrasted through different works of literature. Then the excavated remains of geum-textiles were analyzed and the characteristics of the geum-textiles were defined in chronological order. The origin of wie-geum is traced back to the time when West Asia started to imitate the weaving style of the East Asian gyeong-geum. When combined with the weaving skills of the West Asian, gyeong-geum, which broke through the West and developed into the weft-faced compound twill silk, or samite. The exchange of geum-textiles took place as the techniques of gastric filament woven geum-textiles returned to the East. Along with the pearl roundel motifs of Sassanian Persia, mythical animals and western motifs of hunter patterns were used for the patterns of wie-geumin during the early Tang dynasty. This tendency is related to pa-sa-geum(波斯錦), ho-geum(胡錦), beon-geum(番錦) according to the recorded literature. The 8th and 9th century are periods when the West Asian Persian style was abandoned and the East Asian style, samite, was established. Not only did S twist silk threads replace Z twists, but also the repetition of patterns unfolded along with the weft and the warp. As this tendency was strengthened after the 9th century, the expression of patterns became more vividly colorful and showed both elements of naturalism and realism. The characteristics of the Bosangwha(寶相花) pattern in the Tang period were established with the rampantly repeated rosettes with birds often holding auspicious branches, that fly amid floral compositions.

Analysis of Changing Aspect of Korean Cultural Contents in Japanese Textbooks (일본 교과서에 나타난 한국문화 콘텐츠 변화 양상 분석)

  • Park, So-Young
    • The Journal of the Korea Contents Association
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    • v.13 no.11
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    • pp.492-501
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    • 2013
  • This study is aimed to track down on changes in the way Korean culture was covered in Japanese textbooks over the past three decades since the 1980s by reviewing 'social studies' textbooks for the 6th graders in elementary school and 'geology' textbooks for middle school, which are two compulsory subjects in Japanese schools where Korean cultures is the most often mentioned. To that end, Korean culture contents mentioned in the textbooks were classified into basic element, unique element and element that reflect the times, each of which was then divided into the categories of traditional & modern and surface & in-depth so as to see how each of the categories was presented. Japanese textbooks mentioned mostly surface and basic elements of Korean culture relating to food, clothing and shelter, such as Hanbok, Kimchi, Ondol, high-rise apartment and table manners, and also landscape of Seoul. Also, the kinds of contents which constantly appeared in the textbook were mostly basic elements including to food, clothing and shelter. Elements that reflect the times such as the 1988 Seoul Olympic Games, the 2002 Korea-Japan World Cup and the Korean Wave were adequately covered as part of chronological explanations in the books. The aspect of Korean culture in Japanese textbooks seems to expand in depth and scope over the years. More recently, detailed explanations and visual images were increasingly used to introduce Korean culture.

Archaeomagnetic Dating of Hemp Kiln and Lime Kiln (삼가마와 회가마의 고고지자기 연대)

  • Sung, Hyong-Mi
    • Journal of Conservation Science
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    • v.27 no.3
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    • pp.291-300
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    • 2011
  • Archaeomagnetic dating method is used to assign a date to the archaeological remains in which burnt soil is found by measuring the changes in terrestrial magnetism with the thermal remanent magnetization retained in burnt soil. This method, in particular, is quite useful to determine an age of the archaeological remains in which no properties are found, which makes it difficult to assigning a date. Hemp kiln and lime kiln fall under remains of these features, and 21 and 5 archaeomagnetic data from both kilns respectively were obtained by measuring the- remanent magnetization in burnt soil samples that are extracted in hemp kilns and lime kilns in the country. The results of archaeomagnetic dating with these data show the age range of the hemp kilns is between the late 10th century A.D. and the middle of the 19th century, and that of the lime kilns is between the early 16th century A.D. and the middle of the 18th century. The factor that the number of data collected from the hemp kilns was comparatively more than those from the lime kilns might affect the result, however corresponding to the fact that hemp had been used for a long period of time, the period of hemp kiln are widely spread over the chronological table. And the archaeomagnetic dating of lime kiln, in view of archaeological periods, is not only in accord with the late Joseon period when the tombs with lime-soil mixture barrier in trend; this is also telling that its width of archaeological period is comparatively narrow.

Anti-skin Aging Potential of Alcoholic Extract of Phragmites communis Rhizome

  • Ha, Chang Woo;Kim, Sung Hyeok;Lee, Sung Ryul;Jang, Sohee;Namkoong, Seung;Hong, Sungsil;Lim, Hyosun;Kim, Youn Kyu;Sohn, Eun-Hwa
    • Korean Journal of Plant Resources
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    • v.33 no.6
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    • pp.604-614
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    • 2020
  • Chronological aging and photoaging affect appearance, causing wrinkles, pigmentation, texture changes, and loss of elasticity in the skin. Phragmites communis is a tall perennial herb used for its high nutritional value and for medicinal purposes, such as relief from fever and vomiting and facilitation of diuresis. In this study, we investigated the effects of ethanol extract of P. communis rhizome (PCE) on skin aging. The total flavonoid and total phenolic content in PCE were 2.92 ± 0.007 ㎍ of quercetin equivalents (QE) and 231.8 ± 0.001 ㎍ of gallic acid equivalents (GAE) per 100 mg of dried extract (n = 3). The half-maximal inhibitory concentration (IC50) values of PCE for 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and hydrogen peroxide scavenging activities were 0.96 and 0.97 mg/mL, respectively. PCE showed inhibitory effects on tyrosinase when L-tyrosine (IC50 = 1.25 mg/mL) and L-3,4-dihydroxyphenylalanine (IC50 = 0.92 mg/mL) were used as substrates. PCE treatment up to 200 ㎍/mL for 24 h did not cause any significant cytotoxicity in B16F10 melanocytes, human dermal fibroblasts (HDFs), and HaCaT keratinocytes. In B16F10 melanocytes, PCE (25 and 50 ㎍ /mL) inhibited melanin production and cellular tyrosinase activity after challenge with α-melanocyte-stimulating hormone (α-MSH; p < 0.05). In HDFs, PCE suppressed the mRNA expression of matrix metalloproteinase-1 (MMP-1) and reduced the activity of elastase (p < 0.05). In addition, ultraviolet B (UVB)-mediated downregulation of hyaluronic acid synthase-2 gene expression in HaCaT keratinocytes was also effectively suppressed by PCE treatment. Overall, our results showed that PCE has potential anti-skin aging activity associated with the suppression of hyperpigmentation, wrinkle formation, and reduction in dryness. PCE is a promising candidate for the development of an anti-skin aging cosmetic ingredient.

Music Teachers' Perceptions of the Music Therapy Curriculum in Special Education Schools (특수학교 음악교과의 운영과 음악치료적 접근에 대한 교사인식)

  • Gu, Sin-Sil;Hwang, Soon-Young
    • Journal of Music and Human Behavior
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    • v.16 no.1
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    • pp.89-117
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    • 2019
  • The purpose of this study was to explore and better understand special education music teachers' perceptions of their music curriculum. For this purpose, we conducted a focus group interview with seven special education music teachers. During the interview, four major themes and 14 sub-themes were identified. The main themes were the following: (a) types of applied activities and the goals of music classes (e.g., activities to be applied in various ways depending on the characteristics of the disability and intended outcome), (b) difficulty in implementing the music curriculum (e.g., lack of fit between textbook and students' chronological ages, lack of time and focus, self-evaluation of performance as a music teacher, (c) therapeutic experiences during music classes (e.g., expectation for positive effects through music therapy, joy of witnessing changes in students, and sense of togetherness), and (d) obstacles to the therapeutic approach of music classes and need for support (e.g., lack of professional knowledge regarding therapeutic approaches and problems with administrators and school environment). Based on these results, problems in implementing the music therapy approach as part of the music curriculum in special education schools are discussed and practical solutions for educators are offered.

Publication Dating through Observations of Differences in Woodblock Printing Characteristics among Various Versions of Wanpanbon Editions of Honggildongjeon (Tale of Hong Gil Dong) (완판본(完板本) 홍길동전 판본 간에 나타난 목판인쇄 특징의 차이점 관찰을 통한 간행 연대의 추정)

  • Yoo, Choon Dong;Yoo, Woo Sik
    • Journal of Conservation Science
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    • v.38 no.2
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    • pp.96-108
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    • 2022
  • 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.

A Diachronic Study on the Transition Process of the Royal Library during the Gojong Period (고종대 왕실도서관의 변천 과정에 관한 통시적 고찰)

  • Song, Sung-Seob
    • Journal of the Korean Society for Library and Information Science
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    • v.56 no.3
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    • pp.213-239
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    • 2022
  • This study attempted to organize the transition process of Royal Library (Gyujanggak) in chronological order, analyze the flow and find diachronic meaning during Gojong period, the most confused time at home and abroad prior to modernization. For this, first, the total status quo of King Gojong's library and book storage which played role of Royal Library and a personal library in Gojong period was investigated. Second, based on the current status of the investigation, the transition process from the Royal library in the early days of King Gojong to the Imperial library during the Korean Empire and its meaning were considered with the Annals of the Joseon Dynasty, Seungjeongwon diary, various catalogs and historical records. Third, the changes of space-time and aspect of Royal library through the palace of Gyeongbokgung, Changdeokgung, and Gyeongungung were examined to draw a sociopolitical meaning by schematizing each palace. As a result, first, King Gojong conjugated Kyujanggak as a device to strengthen the royal authority and accommodate Western culture in the process of modernization. Second, the crucial spaces containing the political orientation of King Gojong, such as the present king's portrait storage place, library(book storage), and office, formed a separate hall across Gyeongbokgung, Changdeokgung, Gyeongungung, and gradually changed into a Western architectural style.