• Title/Summary/Keyword: Reconstruct

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An Electrical Conductivity Reconstruction for Evaluating Bone Mineral Density : Simulation (골 밀도 평가를 위한 뼈의 전기 전도도 재구성: 시뮬레이션)

  • 최민주;김민찬;강관석;최흥호
    • Journal of Biomedical Engineering Research
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    • v.25 no.4
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    • pp.261-268
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    • 2004
  • Osteoporosis is a clinical condition in which the amount of bone tissue is reduced and the likelihood of fracture is increased. It is known that the electrical property of the bone is related to its density, and, in particular, the electrical resistance of the bone decreases as the bone loss increases. This implies that the electrical property of bone may be an useful parameter to diagnose osteoporosis, provided that it can be readily measured. The study attempted to evaluate the electrical conductivity of bone using a technique of electrical impedance tomography (EIT). It nay not be easy in general to get an EIT for the bone due to the big difference (an order of 2) of electrical properties between the bone and the surrounding soft tissue. In the present study, we took an adaptive mesh regeneration technique originally developed for the detection of two phase boundaries and modified it to be able to reconstruct the electrical conductivity inside the boundary provided that the geometry of the boundary was given. Numerical simulation was carried out for a tibia phantom, circular cylindrical phantom (radius of 40 mm) inside of which there is an ellipsoidal homeogenous tibia bone (short and long radius are 17 mm and 15 mm, respectively) surrounded by the soft tissue. The bone was located in the 15 mm above from the center of the circular cross section of the phantom. The electrical conductivity of the soft tissue was set to be 4 mS/cm and varies from 0.01 to 1 ms/cm for the bone. The simulation considered measurement errors in order to look into its effects. The simulated results showed that, if the measurement error was maintained less than 5 %, the reconstructed electrical conductivity of the bone was within 10 % errors. The accuracy increased with the electrical conductivity of the bone, as expected. This indicates that the present technique provides more accurate information for osteoporotic bones. It should be noted that tile simulation is based on a simple two phase image for the bone and the surrounding soft tissue when its anatomical information is provided. Nevertheless, the study indicates the possibility that the EIT technique may be used as a new means to detect the bone loss leading to osteoporotic fractures.

Combined Reconstruction of Posterior Cruciate Ligament and Posterolateral Corner with a Fresh Frozen Achilles Tendon Allograft (한 개의 신선동결 동종아킬레스건을 이용한 후방십자인대 및 후외방구조의 동시 재건술)

  • Kyung, Hee-Soo;Oh, Chang-Wug;Lee, Hyun-Joo;Ihn, Joo-Chul
    • Journal of Korean Orthopaedic Sports Medicine
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    • v.8 no.2
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    • pp.102-108
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    • 2009
  • Purpose: The purpose of this study is to report a result of the technique that reconstruct posterior cruciate ligament (PCL) and posterolateral corner (PLC) simultaneously using a fresh-frozen Achilles tendon allograft. Materials and Methods: Forty two patients (45 legs) underwent PCL and PLC reconstruction were included. There were 38 males and 4 females. Mean age was 39 years. Used graft was a fresh frozen Achilles tendon allograft, which was divided by two size, larger one (${\emptyset}$ 10 mm) for PCL reconstruction and smaller one (${\emptyset}$ 8 mm) for PLC reconstruction. Arthroscopic reconstruction of the PCL was performed using transtibial, single incision, and single bundle technique with 10mm fresh frozen Achilles allograft tendon first. After PCL reconstruction, reconstruction procedure for posterolateral instability was performed using modified figure of "8" technique using smaller gtaft. For clinical evaluation, range of motion, posterior drawer test, varus stress test, prone external rotation (dial) test, Lysholm score, Tegner activity scale and posterior stress radiograph were used. Mean follow up period was 25 months. Results: Preoperatively posterior drawer test was 5 cases in grade II and 40 cases in grade III posterior instability. At final follow-up 22 cases returned within normal condition, 18 cases grade I and 5 cases grade II posterior instability. Though all patients showed positive result over 10 degrees in dial and varus stress test preoperatively, but only 9 cases showed positive both test at final follow-up. The range of motion deficit over $10^{\circ}$ flexion was 3 cases. Lysholm score was improved from mean 50 preoperatively to mean 83(p<0.05) and Tegner activity scale improved from mean 2.1 preoperatively to mean 4.6(p<0.05). In posterior stress radiographs, posterior displacement was improve from mean 16mm preoperatively to 4.1mm after treatment(p<0.05). All patients had improved compared to their pre-operative status as measured by physical examination such as posterior drawer test, varus stress test, dial test. Conclusion: We had successful results by combined reconstruction of the PCL & PLC with a fresh frozen Achilles tendon allograft in patients with PCL and posterolateral rotatory instability at a time.

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Playing with Rauschenberg: Re-reading Rebus (라우센버그와 게임하기-<리버스> 다시읽기)

  • Rhee, Ji-Eun
    • The Journal of Art Theory & Practice
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    • no.2
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    • pp.27-48
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    • 2004
  • Robert Rauschenberg's artistic career has often been regarded as having reached its culmination when the artist won the first prize at the 1964 Venice Biennale. With this victory, Rauschenberg triumphantly entered the pantheon of all-American artists and firmly secured his position in the history of American art. On the other hand, despite the artist's ongoing new experiments in his art, the seemingly precocious ripeness in his career has led the critical discourses on Rauschenberg's art to the artist's early works, most of which were done in the mid-1950s and the 1960s. The crux of Rauschenberg criticism lies not only in focusing on the artist's 50's and 60's works, but also in its large dismissal of the significance of the imagery that the artist employed in his works. As art historians Roger Cranshaw and Adrian Lewis point out, the critical discourse of Rauschenberg either focuses on the formalist concerns on the picture plane, or relies on the "culturalist" interpretation of Rauschenberg's imagery which emphasizes the artist's "Americanness." Recently, a group of art historians centered around October has applied Charles Sanders Peirce's semiotics as art historical methodology and illuminated the indexical aspects of Rauschenberg's work. The semantic inquiry into Rauschenberg's imagery has also been launched by some art historians who seek the clues in the artist's personal context. The first half of this essay will examine the previous criticism on Rauschenberg's art and the other half will discuss the artist's 1955 work Rebus, which I think intersects various critical concerns of Rauschenberg's work, and yet defies the closure of discourses in one direction. The categories of signs in the semiotics of Charles Sanders Peirce and the discourse of Jean-Francois Lyotard will be used in discussing the meanings of Rebus, not to search for the semantic readings of the work, hut to make an analogy in terms of the paradoxical structures of both the work and the theory. The definitions of rebus is as follows: Rebus 1. a representation or words or syllables by pictures of object or by symbols whose names resemble the intended words or syllables in sound; also: a riddle made up wholly or in part of such pictures or symbols. 2. a badge that suggests the name of the person to whom it belongs. Webster's Third New International Dictionary of the English Language Unabridged. Since its creation in 1955, Robert Rauschenberg's Rebus has been one of the most intriguing works in the artist's oeuvre. This monumental 'combine' painting($6feet{\times}10feet$ 10.5 inches) consists of three panels covered with fabric, paper, newspaper, and printed reproductions. On top of these, oil paints, pencil and crayon drawings connect each section into a whole. The layout of the images is overall horizontal. Starting from a torn election poster, which is partially read as "THAT REPRE," on the far left side of the painting. Rebus leads us to proceed from the left to the right, the typical direction of reading in a Western context. Along with its seemingly proper title. Rebus, the painting has triggered many art historians to seek some semantic readings of it. These art historians painstakingly reconstruct the iconography based on the artist's interviews, (auto)biography, and artistic context of his works. The interpretation of Rebus varies from a 'image-by-image' collation with a word to a more general commentary on Rauschenberg's work overall, such as a work that "bridges between art and life." Despite the title's allusion to the legitimate purpose of the painting as a decoding of the imagery into sound, Rebus, I argue, actually hinders a reading of it. By reading through Peirce to Rauschenberg, I will delve into the subtle anxiety between words and images in their works. And on this basis, I suggest Rauschenberg's strategy in playing Rebus is to hide the meaning of the imagery rather than to disclose it.

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Comparison of Anterior Cruciate Ligament Reconstruction using Autogenous Patellar Tendon versus Quadruple Hamstring Tendon (자가 슬개건과 네 겹 슬괵건을 이용한 전방 십자 인대 재건술의 비교)

  • Kim, Seok-Jung;Kwon, Oh-Soo;Choi, Dong-Won;Song, Ho-Wook;Kang, Hyun-Taek;In, Yong
    • Journal of the Korean Arthroscopy Society
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    • v.8 no.1
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    • pp.19-25
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    • 2004
  • Purpose: To compare the results of two different autografts used to reconstruct the anterior cruciate ligament(ACL): bone-patellar tendon-bone and quadruple hamstring tendon. Materials and Methods: Forty one cases (20 bone-patellar tendon-bone cases and 21 quadruple hamstring tendon cases) were followed up more than 2 years postoperatively. Patellar tendons were fixed with interference screws and hamstring tendons were fixed with cross pins and intrafix sheaths and screws. Follow-up results were evaluated with KT-2000 arthrometer, International knee Documentation Committee(IKDC) evaluation form and follow up X-ray Donor site morbidity was analysed. Results: Final IKDC) scores more than B grade and side to side differences of manual maximum test using KT-2000 arthrometer showed insignificant differences(p>) between the two groups. Plain radiographs of hamstring group showed marked widening of the femoral and tibial tunnels at postoperative 2 years. Patellar tendon group showed 30% rate of anterior knee complications. Conclusion: ACL reconstruction using autogenous hamstring graft with new fixation method showed comparable clinical results to using autogenous patellar tendon graft with fewer anterior knee symptoms.

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Barrier Techniques for Spinal Cord Protection from Thermal Injury in Polymethylmethacrylate Reconstruction of Vertebral Body : Experimental and Theoretical Analyses (Polymethylmethacrylate를 이용한 척추체 재건술에서 척수의 열 손상을 방지하기 위한 방어벽 기법 : 실험적 및 이론적 분석)

  • Park, Choon Keun;Ji, Chul;Hwang, Jang Hoe;Kwun, Sung Oh;Sung, Jae Hoon;Choi, Seung Jin;Lee, Sang Won;Park, Sung Chan;Cho, Kyeung Suok;Park, Chun Kun;Yuan, Hansen;Kang, Joon Ki
    • Journal of Korean Neurosurgical Society
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    • v.30 no.3
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    • pp.272-277
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    • 2001
  • Objective : Polymethylmethacrylate(PMMA) is often used to reconstruct the spine after total corpectomy, but the exothermic curing of liquid PMMA poses a risk of thermal injury to the spinal cord. The purposes of this study are to analyze the heat blocking effect of pre-polymerized PMMA sheet in the corpectomy model and to establish the minimal thickness of PMMA sheet to protect the spinal cord from the thermal injury during PMMA cementation of vertebral body. Materials & Methods : An experimental fixture was fabricated with dimensions similar to those of a T12 corpectomy defect. Sixty milliliters of liquid PMMA were poured into the fixture, and temperature recordings were obtained at the center of the curing PMMA mass and on the undersurface(representing the spinal cord surface) of a prepolymerized PMMA sheet of variable thickness(group 1 : 0mm, group 2 : 5mm, or group 3 : 8mm). Six replicates were tested for each barrier thickness group. Results : Consistent temperatures($106.8{\pm}3.9^{\circ}C$) at center of the curing PMMA mass in eighteen experiments confirmed the reproducibility of the experimental fixture. Peak temperatures on the spinal cord surface were $47.3^{\circ}C$ in group 2, and $43.3^{\circ}C$ in group 3, compared with $60.0^{\circ}C$ in group 1(p<0.00005). So pre-polymerized PMMA provided statistically significant protection from heat transfer. The difference of peak temperature between theoretical and experimental value was less than 1%, while the predicted time was within 35% of experimental values. The data from the theoretical model indicate that a 10mm barrier of PMMA should protect the spinal cord from temperatures greater than $39^{\circ}C$(the threshold for thermal injury in the spinal cord). Conclusion : These results suggest that pre-polymerized PMMA sheet of 10mm thickness may protect the spinal cord from the thermal injury during PMMA reconstruction of vertebral body.

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A Study on practical use about Kinetic Typography of Ethics Character Picture of filial piety and brotherly love (효제문자도(孝悌文字圖)의 키네틱 타이포그래피 활용 연구)

  • Chung, Chi-Won
    • Cartoon and Animation Studies
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    • s.50
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    • pp.327-347
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    • 2018
  • From the end of the 18th century to the end of the 19th century, the late 19th century was a genre of a new art that was in contrast to the distribution between social class and low class, and it was also a popular culture that attempted to transform the late Joseon Dynasty's social class. It is no exaggeration to say that it is the origin of the Korean folk art, started as popular art concepts, use colorful techniques and decorations which doesn't yield to ordinary iconography. But, because of the attempt of this technique was used by lower class, the meaning of the idea was lowered from iconography to secular picture. Ethics character picture, passed on to the present from going through the upheaval cultural time, was started from secular picture and transformed into hyukpil time illustration, and it represented popular arts until now. This thesis aims to reflect the meaning, various visual expressions and the lifestyle of Ethics Character Picture of filial piety and brotherly love, which is a unique genre of popular arts. Also, propose to suggest about the kinetic typography using video media, and how the traditional ethics character picture, which are combined with video technology, effects to the advertisements. These kind of attempts will show the world about the korea's traditional contents, and through the various media information it can be recreated as national symbolic key words. Furthermore, its meaningful to pass down the noble and cultural Ethics Character Picture of filial piety and brotherly love to younger generations. And by realigning to modern expression, it is predicted that it will be significantly meaningful to pass down and make the younger generations to understand to spirit of the ancestors. This will allow various attempts to reconstruct various items of contents from Korea's traditional contents to new media content that merged with video media.

A Study on Understanding of Middle-East Terrorism : Focusing on Islamic Fundamentalism (이슬람 원리주의를 통해 본 중동지역테러리즘의 이해)

  • Park, Gi-Beom;Kang, Min-Wan;Jun, Yong-Tae
    • Korean Security Journal
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    • no.12
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    • pp.149-175
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    • 2006
  • The purpose of this study is to understand and analyze the character of Islamic fundamentalism and Middle-Ease Terrorism. The aim of Islamic fundamentalism is reconstruction of Ummah(Muslim Unity), thee early society of Muhammad's age. Islamic movement insist to restore the spirit of Islam and purify the society of Islam from the United State and Western world. Now, Islamic fundamentalism movement as a new ideology, appeals to muslim in the world. The concept of modern national state from the Western countries do not accord with the traditional Islamic principles of reign and a spirit of nationalism. On the other hand, Islamic movement have no legitimacy in the system of modern state which govern the Arab world, regardless of the form of government. For this reasons, Islamic fundamentalist have an insecure position and their political activities. It is yet far from their purpose, to reconstruct the muslim unity, to realize the Islamic political principle close to their practical methods. Yet Islamic fundamental movement have not overcome the system of secular state. The Middle East terrorism supported by government might be eradicated by America's anti-terrorism policy. However, it will be serious and spread all over the world that the terrorist attack against the U. S. and western countries is acted by militant warriors of Islamic fundamentalism, uniting Arab and Islamic people's emotions against America and western countries. There are some reasons that we need to focus on the Arab and Islamic fundamentalism. We need to get out of misunderstanding and discrimination about Islamic religion and culture from America's and Western' standard Which are only their new world order. The discrimination of America and western nations against muslim could make other ideologies, opposite to the world peace. There are a lot of foreign workers from Islam countries in Korea. We need to give consideration and attention to them for the our globalization and world peace. It is time to consider what to do for the nation's profit(economical, political, strategic)with right understanding. We are not safe and free from the terrorism yet.

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A study on the traditional salt-making of the Joolpo inlet area during the 18th and 19th century (18~19世紀 茁浦灣의 煮鹽 - 鹽場의 分布와 煮鹽法을 중심으로 -)

  • ;Hong, Keum-Soo
    • Journal of the Korean Geographical Society
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    • v.29 no.1
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    • pp.46-64
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    • 1994
  • Among every civilized people salt has been recognized as an essential foodstuff to the human society without which even man's survivor is unthinkable. The cultural-anthropological meaning of salt is estimated highly as well, and in geographical perspective salt itself symbolize regional interrelationship. Playing a decisive role in freeing innermost settlement from isolation, salt aiso made a contribution to expanding human habitats. This study tries to reconstruct historica geography of 18th and 19th century surrounding traditional salt-roasting (chayeom). The Joolpo Inlet area which is located on the mid-western coast in Honem Region is selected for study area. Established on the basis of optimum physical geographical conditions such as topography, climate and vegetation, salt-making of Joolpo Inlet area was run dynamically with the sudden turn of events in the 18-19th century which was chacterized as an age of transition from medieval society to modern one. In this paper the writer attempts to clarify mainly following three points: physical conditions and socio-economic background leading to the initiation and later development of roasting of salt in Joolpo Bay; distribution of saltworks; methods of saltmaking. Main points drawn from these analyses can be summarized as follows: of iron pan and cow-drawn tools rendered labour-saving and output growth. 1, Saltworks of Joolpo Inlet area in the 18-19th century were distributed evenly over Kobu, Puan, Mujang and Heungduck counties among which Kobu's was located in Puanmyon - a sort of exclave. All saltworks belonging to above four counties were clasified as most lucrative ones in Honam Region on government archives. In particular, Gumdang saltwork which belongs to Mujang county is noteworthy in that it was first introduced by one Paekje priest in 6th century and therefore it provides a clue to examine the history of salt-roasting of Joolpo Inlet area. In light of the fact that temple or monastery economy, regardless of East and West, has been closely connected with traditional industry, the case of Gumdang is not unusual. 2. The process of saltmaking follows this order: harrowing of salt field exposed to solar heat; construction of saltern mound with saline earth; acquiring of brine by leaching saline earth; roasting of salt. Salterns (saltworks) are consisted with various salt making facilities such as roasting shed, saltern mound, salt field, salt well) salt pit or brine pit) and seawater reservoir. Among them roasting shed which is constructed chiefly with hundreds of pieces of pine tree as a frame and with straw as roof and wall is customarily considered as an unit of saltwork. And inside it is saltpan made of two kinds of materials, that is iron pan or plaster pan. The area attached to one unit of roasting shed is approximately 1 ha, and that of saltern mound is a tenth of it.

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Evaluation of TOF MR Angiography and Imaging for the Half Scan Factor of Cerebral Artery (유속신호증강효과의 자기공명혈관조영술을 이용한 뇌혈관검사에서 Half Scan Factor 적용한 영상 평가)

  • Choi, Young Jae;Kweon, Dae Cheol
    • Journal of the Korean Magnetics Society
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    • v.26 no.3
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    • pp.92-98
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    • 2016
  • To aim of this study was to assess the full scan and half scan of imaging with half scan factor. Patients without a cerebral vascular disease (n = 30) and were subject to the full scan half scan, and set a region of interest in the cerebral artery from the three regions (C1, C2, C3) in the range of 7 to 8 mm. MIP (maximum intensity projection) to reconstruct the images in signal strength SNR (signal to noise ration), PSNR (peak signal noise to ratio), RMSE (root mean square error), MAE (mean absolute error) and calculated by paired t-test for use by statistics were analyzed. Scan time was half scan (4 minutes 53 seconds), the full scan (6 minutes 04 seconds). The mean measurement range (7.21 mm) of all the ROI in the brain blood vessel, was the SNR of the first C1 is completely scanned (58.66 dB), half-scan (62.10 dB), a positive correlation ($r^2=0.503$), for the second C2 SNR is completely scanned (70.30 dB), half-scan (74.67 dB) the amount of correlation ($r^2=0.575$), third C3 of a complete scan SNR (70.33 dB), half scan SNR (74.64 dB) in the amount of correlation between the It was analyzed with ($r^2=0.523$). Comparative full scan with half of SNR ($4.75{\pm}0.26dB$), PSNR ($21.87{\pm}0.28dB$), RMSE ($48.88{\pm}1.61$), was calculated as MAE ($25.56{\pm}2.2$). SNR is also applied to examine the half-scans are not many differences in the quality of the two scan methods were not statistically significant in the scan (p-value > .05) image takes less time than a full scan was used.

Geochemical Characteristics and Quaternary Environmental Change of Unconsolidated Sediments from the Seokgwan-dong Paleolithic Site in Seoul, Korea (서울 석관동 유적의 미고결 퇴적층의 지구화학적 특성 및 제4기 지표환경변화)

  • Lee, Hyo-Min;Lee, Jin-Young;Kim, Ju-Yong;Hong, Sei-Sun;Park, Jun-Bum
    • The Journal of the Petrological Society of Korea
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    • v.25 no.4
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    • pp.373-388
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    • 2016
  • To understand human activity in the past, the information about past environmental change including geomorphological and climatic conditions is essential and this can be traced by using age dating and geochemical analysis of sediments from the prehistoric sites. The sedimentary sequence of Seokgwan-dong Paleolithic Site located in Seoul was 5m long unconsolidated sediments and consists of lower part bedrock weathering sediments, slope deposits and upper-part fluvial deposits. In this study, upper part sediments were used to reconstruct past environmental change through age dating and various physical and chemical analyses including grain size, magnetic susceptibility and mineral and elements. The fluvial sediments can be divided into 4 units including three organic layers. Grain size analysis results showed that the sediments were very poorly sorted with fining upward features. Magnetic susceptibility was relatively high in the organic layers, indicating environmental changes causing mineral composition change at that times. The mineral and major element composition are similar to Jurassic biotite granite which mainly consists of quartz, K-feldspar, biotite and muscovite. The radiocarbon age of $14,240{\pm}80yr$ BP was obtained from the lower most organic layer of Unit III(O), suggesting that the fluvial sediments formed at least from the early stage of deglacial period after the end of Last Glacial Maximum. Subsequent wet and warm climates and resultant fluvial process including slope sedimentation during the Holocene may have been responsible for the sedimentary sequence in Seokgwan-dong paleolithic site and surrounding area. The observed organic layers suggests frequent wetland occurrence combined with natural levee changes in this area.