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The Pattern of Initial Displacement in Lingual Lever Arm Traction of 6 Maxillary Anterior Teeth According to Different Material Properties: 3-D FEA (유한요소모델에서 레버암을 이용한 상악 6전치 설측 견인 시 초기 이동 양상)

  • Choi, In-Ho;Cha, Kyung-Suk;Chung, Dong-Hwa
    • Journal of Dental Rehabilitation and Applied Science
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    • v.24 no.2
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    • pp.213-230
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    • 2008
  • The aim of this study was to analyze the initial movement and the stress distribution of each tooth and periodontal ligament during the lingual lever-arm retraction of 6 maxillary incisors using FEA. Two kinds of finite element models were produced: 2-properties model (simple model) and 24-properties model (multi model) according to the material property assignment. The subject was an adult male of 23 years old. The DICOM images through the CT of the patient were converted into the 3D image model of a skull using the Mimics (version 10.11, Materialise's interactive Medical Image Control System, Materialise, Belgium). After series of calculating, remeshing, exporting, importing process and volume mesh process was performed, FEA models were produced. FEA models are consisted of maxilla, maxillary central incisor, lateral incisor, canine, periodontal ligaments and lingual traction arm. The boundary conditions fixed the movements of posterior, sagittal and upper part of the model to the directions of X, Y, Z axis respectively. The model was set to be symmetrical to X axis. Through the center of resistance of maxilla complex, a retraction force of 200g was applied horizontally to the occlusal plane. Under this conditions, the initial movements and stress distributions were evaluated by 3D FEA. In the result, the amount of posterior movement was larger in the multi model than in the simple model as well as the amount of vertically rotation. The pattern of the posterior movement in the central incisors and lateral incisors was controlled tipping movement, and the amount was larger than in the canine. But the amount of root movement of the canine was larger than others. The incisor rotated downwardly and the canines upwardly around contact points of lateral incisor and canine in the both models. The values of stress are similar in the both simple and multi model.

Studies on the control of brown planthoppers with Padan 4G and several factors governing the insect mortality (Padan 입제(4G)의 벼멸구 방제효과 및 살충효과에 미치는 몇가지 요인에 관한 연구)

  • Chang Y. D.;Choi S.Y.
    • Korean journal of applied entomology
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    • v.23 no.4 s.61
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    • pp.221-232
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    • 1984
  • A series of experiments were carried out in the laboratory and fields to reevaluate the effects of Padan (cartap) to the brown planthopper (BPH). Nilapanata lugens. The $LD_{50}\;land\;LC_{50}$ values for the female and male BPH were determined by the topical application and seedling- dipping/root -soaking methods. The values were differed with the sex and test methods, and the BPH mortality was greatly increased with a rise in temperatures $(25-35^{\circ}C)$. In a viewpoint of honeydew excretion and offsprings produced, there was no any possibility in BPH resurgence at the sublethal exposures of Padan. The BPH mortality to Padan 4 G was greatly low in the pot tests compared with those to diazinon and carbofuran, but in the paddy fields the efficacy of Padan 4G was nearly reversed. A single application of Padan 4G at the rate of 4kg/10a dramatically suppressed the BPH populations in the paddy fields, and the control effect was much more accelerated in the drained paddy field than in the submerged paddy field.

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MICROHARDNESS AND SURFACE ROUGHNESS OF SEALANT AND FLOWABLE COMPOSITE RESINS (치면열구전색제와 유동성 복합 레진의 미세 경도 및 표면 조도의 비교)

  • Yang, Kyu-Ho;Choi, Nam-Ki;Kim, Seon-Mi;Choi, Ji-Eun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.36 no.3
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    • pp.440-447
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    • 2009
  • This study was performed to compare the wear resistance of sealant and flowable resins for analyzing the effect of flowable resin as a sealant in preventive resin restorations. Specimens were made and Vicker's hardness number and surface roughness were measured. SEM observations of the polished and abraded surfaces were established. Kruskal-Wallis rank test and Mann-Whitney U test at the significant level of ${\alpha}$=0.05 were used. The following results were obtained: 1. The microhardness was decreased among groups in following order: Z350 (3M ESPE, U.S.A), Estelite (Tokuyama Dental, Japan) and Ultraseal (Ultradent, U.S.A). There were significant differences in all groups (p<0.0001). 2. The surface roughness was decreased among groups in following order: Ultraseal XT plus, Palfique Estelite LV and Filtek Z350 flowable. However, there is no statistically significant differences in roughness among Estellite, Z350 and Ultraseal at the significance level of ${\alpha}$=0.05, with p=0.116 3. SEM observation of the unworn and worn surfaces revealed the qualitative differences in the wear appearance among groups. The results in this study indicate that flowable resin is better than sealant in aspect of physical properties.

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THE LUMINOSITY-LINEWIDTH RELATION AS A PROBE OF THE EVOLUTION OF FIELD GALAXIES

  • GUHATHAKURTA PURAGRA;ING KRISTINE;RIX HANS-WALTER;COLLESS MATTHEW;WILLIAMS TED
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.63-64
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    • 1996
  • The nature of distant faint blue field galaxies remains a mystery, despite the fact that much attention has been devoted to this subject in the last decade. Galaxy counts, particularly those in the optical and near ultraviolet bandpasses, have been demonstrated to be well in excess of those expected in the 'no-evolution' scenario. This has usually been taken to imply that galaxies were brighter in the past, presumably due to a higher rate of star formation. More recently, redshift surveys of galaxies as faint as B$\~$24 have shown that the mean redshift of faint blue galaxies is lower than that predicted by standard evolutionary models (de-signed to fit the galaxy counts). The galaxy number count data and redshift data suggest that evolutionary effects are most prominent at the faint end of the galaxy luminosity function. While these data constrain the form of evolution of the overall luminosity function, they do not constrain evolution in individual galaxies. We are carrying out a series of observations as part of a long-term program aimed at a better understanding of the nature and amount of luminosity evolution in individual galaxies. Our study uses the luminosity-linewidth relation (Tully-Fisher relation) for disk galaxies as a tool to study luminosity evolution. Several studies of a related nature are being carried out by other groups. A specific experiment to test a 'no-evolution' hypothesis is presented here. We have used the AUTOFIB multifibre spectro-graph on the 4-metre Anglo-Australian Telescope (AAT) and the Rutgers Fabry-Perot imager on the Cerro Tolalo lnteramerican Observatory (CTIO) 4-metre tele-scope to measure the internal kinematics of a representative sample of faint blue field galaxies in the red-shift range z = 0.15-0.4. The emission line profiles of [OII] and [OIII] in a typical sample galaxy are significantly broader than the instrumental resolution (100-120 km $s^{-l}$), and it is possible to make a reliable de-termination of the linewidth. Detailed and realistic simulations based on the properties of nearby, low-luminosity spirals are used to convert the measured linewidth into an estimate of the characteristic rotation speed, making statistical corrections for the effects of inclination, non-uniform distribution of ionized gas, rotation curve shape, finite fibre aperture, etc.. The (corrected) mean characteristic rotation speed for our distant galaxy sample is compared to the mean rotation speed of local galaxies of comparable blue luminosity and colour. The typical galaxy in our distant sample has a B-band luminosity of about 0.25 L$\ast$ and a colour that corresponds to the Sb-Sd/Im range of Hub-ble types. Details of the AUTOFIB fibre spectroscopic study are described by Rix et al. (1996). Follow-up deep near infrared imaging with the 10-metre Keck tele-scope+ NIRC combination and high angular resolution imaging with the Hubble Space Telescope's WFPC2 are being used to determine the structural and orientation parameters of galaxies on an individual basis. This information is being combined with the spatially resolved CTIO Fabry-Perot data to study the internal kinematics of distant galaxies (Ing et al. 1996). The two main questions addressed by these (preliminary studies) are: 1. Do galaxies of a given luminosity and colour have the same characteristic rotation speed in the distant and local Universe? The distant galaxies in our AUTOFIB sample have a mean characteristic rotation speed of $\~$70 km $s^{-l}$ after correction for measurement bias (Fig. 1); this is inconsistent with the characteristic rotation speed of local galaxies of comparable photometric proper-ties (105 km $s^{-l}$) at the > $99\%$ significance level (Fig. 2). A straightforward explanation for this discrepancy is that faint blue galaxies were about 1-1.5 mag brighter (in the B band) at z $\~$ 0.25 than their present-day counterparts. 2. What is the nature of the internal kinematics of faint field galaxies? The linewidths of these faint galaxies appear to be dominated by the global disk rotation. The larger galaxies in our sample are about 2"-.5" in diameter so one can get direct insight into the nature of their internal velocity field from the $\~$ I" seeing CTIO Fabry-Perot data. A montage of Fabry-Perot data is shown in Fig. 3. The linewidths are too large (by. $5\sigma$) to be caused by turbulence in giant HII regions.

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Expression of Proliferating Cell Nuclear Antigen in Lung Cancer (폐암 조직에서의 Proliferating Cell Nuclear Antigen (PCNA) 발현에 관한 연구)

  • Kim, Sun-Young;Lee, Kyung-Joo;Hong, Suk-Chul;Han, Pyo-Sung;Lee, Jong-Jin;Cho, Hae-Jung;Kim, Ju-Ock
    • Tuberculosis and Respiratory Diseases
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    • v.40 no.1
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    • pp.23-28
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    • 1993
  • Background: Since an important component of carcinogenesis is unregulated growth, many investigators have reported the methods to detect cell proliferation in tissues including PCNA. PCNA is a 36 Kd intranuclear polypeptide and plays a critical role in cell proliferation. Thus progressive dysregulation of proliferation during carcinogenesis can be directly visualized in the paraffin embedded tissue using immunohistochemistry for PCNA which has an advantage of simplicity and maintenance of tissue architecture. The heterogeneity of PCNA expression is known to be related with proliferating fraction, histologic grade, DNA ploidy, and susceptibility of anticancer drugs, etc. We analyzed the biologic significance of the expression of PCNA in lung cancer tissues. Method: 43 lung cancer tissues, which were resected by surgery and were embedded in paraffin, were stained immunohistochemically by one hour MicroProbe System and the results were corelated with cell type, stage, site and survival. Result: 1) Suamous cell type showed high positivity (89%) than in adenocarcinoma (54%). 2) No significant difference related to tumor stage was noticed. 3) No significant difference between primary site and metastatic site was noticed. 4) No significant difference in 12-month survival between positive group and negative group was noticed. Conclusion: From this study, we concluded that imunohistochemistry for PCNA expression of routinely processed tissue is a simple technique for the assessment of proliferation in non-small cell lung cancer. Whether the labelling index has an independent prognostic value and deserves special attention in pathobiological evaluation in lung cancer remains to be investigated from large series with longer follow-up and to be correlated with multiple biological markers.

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Context Prediction Using Right and Wrong Patterns to Improve Sequential Matching Performance for More Accurate Dynamic Context-Aware Recommendation (보다 정확한 동적 상황인식 추천을 위해 정확 및 오류 패턴을 활용하여 순차적 매칭 성능이 개선된 상황 예측 방법)

  • Kwon, Oh-Byung
    • Asia pacific journal of information systems
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    • v.19 no.3
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    • pp.51-67
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    • 2009
  • Developing an agile recommender system for nomadic users has been regarded as a promising application in mobile and ubiquitous settings. To increase the quality of personalized recommendation in terms of accuracy and elapsed time, estimating future context of the user in a correct way is highly crucial. Traditionally, time series analysis and Makovian process have been adopted for such forecasting. However, these methods are not adequate in predicting context data, only because most of context data are represented as nominal scale. To resolve these limitations, the alignment-prediction algorithm has been suggested for context prediction, especially for future context from the low-level context. Recently, an ontological approach has been proposed for guided context prediction without context history. However, due to variety of context information, acquiring sufficient context prediction knowledge a priori is not easy in most of service domains. Hence, the purpose of this paper is to propose a novel context prediction methodology, which does not require a priori knowledge, and to increase accuracy and decrease elapsed time for service response. To do so, we have newly developed pattern-based context prediction approach. First of ail, a set of individual rules is derived from each context attribute using context history. Then a pattern consisted of results from reasoning individual rules, is developed for pattern learning. If at least one context property matches, say R, then regard the pattern as right. If the pattern is new, add right pattern, set the value of mismatched properties = 0, freq = 1 and w(R, 1). Otherwise, increase the frequency of the matched right pattern by 1 and then set w(R,freq). After finishing training, if the frequency is greater than a threshold value, then save the right pattern in knowledge base. On the other hand, if at least one context property matches, say W, then regard the pattern as wrong. If the pattern is new, modify the result into wrong answer, add right pattern, and set frequency to 1 and w(W, 1). Or, increase the matched wrong pattern's frequency by 1 and then set w(W, freq). After finishing training, if the frequency value is greater than a threshold level, then save the wrong pattern on the knowledge basis. Then, context prediction is performed with combinatorial rules as follows: first, identify current context. Second, find matched patterns from right patterns. If there is no pattern matched, then find a matching pattern from wrong patterns. If a matching pattern is not found, then choose one context property whose predictability is higher than that of any other properties. To show the feasibility of the methodology proposed in this paper, we collected actual context history from the travelers who had visited the largest amusement park in Korea. As a result, 400 context records were collected in 2009. Then we randomly selected 70% of the records as training data. The rest were selected as testing data. To examine the performance of the methodology, prediction accuracy and elapsed time were chosen as measures. We compared the performance with case-based reasoning and voting methods. Through a simulation test, we conclude that our methodology is clearly better than CBR and voting methods in terms of accuracy and elapsed time. This shows that the methodology is relatively valid and scalable. As a second round of the experiment, we compared a full model to a partial model. A full model indicates that right and wrong patterns are used for reasoning the future context. On the other hand, a partial model means that the reasoning is performed only with right patterns, which is generally adopted in the legacy alignment-prediction method. It turned out that a full model is better than a partial model in terms of the accuracy while partial model is better when considering elapsed time. As a last experiment, we took into our consideration potential privacy problems that might arise among the users. To mediate such concern, we excluded such context properties as date of tour and user profiles such as gender and age. The outcome shows that preserving privacy is endurable. Contributions of this paper are as follows: First, academically, we have improved sequential matching methods to predict accuracy and service time by considering individual rules of each context property and learning from wrong patterns. Second, the proposed method is found to be quite effective for privacy preserving applications, which are frequently required by B2C context-aware services; the privacy preserving system applying the proposed method successfully can also decrease elapsed time. Hence, the method is very practical in establishing privacy preserving context-aware services. Our future research issues taking into account some limitations in this paper can be summarized as follows. First, user acceptance or usability will be tested with actual users in order to prove the value of the prototype system. Second, we will apply the proposed method to more general application domains as this paper focused on tourism in amusement park.

Evaluation of Set-up Accuracy for Frame-based and Frameless Lung Stereotactic Body Radiation Therapy (폐암 정위체부방사선치료 시 고정기구(frame) 사용 유무에 따른 셋업 정확성 평가)

  • Ji, Yunseo;Chang, Kyung Hwan;Cho, Byungchul;Kwak, Jungwon;Song, Si Yeol;Choi, Eun Kyung;Lee, Sang-wook
    • Progress in Medical Physics
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    • v.26 no.4
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    • pp.286-293
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    • 2015
  • The purpose of this study was to evaluate the set up accuracy using stereotactic body frame and frameless immobilizer for lung stereotactic body radiation therapy (SBRT). For total 40 lung cancer patients treated by SBRT, 20 patients using stereotactic body frame and other 20 patients using frameless immobilizer were separately enrolled in each group. The setup errors of each group depending on the immobilization methods were compared and analyzed. All patients received the dose of 48~60 Gy for 4 or 5 fractions. Before each treatment, a patient was first localized to the treatment isocenter using room lasers, and further aligned with a series of image guidance procedures; orthogonal kV radiographs, cone-beam CT, orthogonal fluoroscopy. The couch shifts during these procedures were recorded and analyzed for systematic and random errors of each group. Student t-test was performed to evaluate significant difference depending on the immobilization methods. The setup reproducibility was further analyzed using F-test with the random errors excluding the systematic setup errors. In addition, the ITV-PTV margin for each group was calculated. The setup errors for SBF were $0.05{\pm}0.25cm$ in vertical direction, $0.20{\pm}0.38cm$ in longitudinal direction, and $0.02{\pm}0.30cm$ in lateral direction, respectively. However the setup errors for frameless immobilizer showed a significant increase of $-0.24{\pm}0.25cm$ in vertical direction while similar results of $0.06{\pm}0.34cm$, $-0.02{\pm}0.25cm$ in longitudinal and lateral directions. ITV-PTV margins for SBF were 0.67 cm (vertical), 0.99 cm (longitudinal), and 0.83 cm (lateral), respectively. On the other hand, ITV-PTV margins for Frameless immobilizer were 0.75 cm (vertical), 0.96 cm (longitudinal), and 0.72 cm (lateral), indicating less than 1 mm difference for all directions. In conclusion, stereotactic body frame improves reproducibility of patient setup, resulted in 0.1~0.2 cm in both vertical and longitudinal directions. However the improvements are not substantial in clinic considering the effort and time consumption required for SBF setup.

Histiocytic necrotizing lymphadenitis in children : association of human herpes virus 8 and Epstein Barr virus (소아에서의 조직구성 괴사성 림프절염 : human herpesvirus 8과 Epstein Barr virus와의 연관성)

  • Kim, Hyun A;Chung, Ju-Young;Kim, Sang Woo;Lim, Sung Jig;Shin, Haeng Seop
    • Clinical and Experimental Pediatrics
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    • v.49 no.8
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    • pp.875-881
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    • 2006
  • Purpose : The aims of this study were to analyze the clinical characteristics of children with Kikuchi's disease(KD) at a medical center and to investigate the etiologic role of human herpesvirus 8(HHV 8) or Epstein-Barr virus(EBV) in children with KD. Methods : Twenty six children who were diagnosed as KD between Jan. 1998 and Dec. 2005 were included. Medical records were reviewed on the clinical characteristics of children with KD. Follow up data were collected by chart review and telephone contact. Polymerase chain reaction(PCR) was performed in order to detect HHV 8 DNA, and in situ hybridization(ISH) was perfomed in order to detect EBV RNA from 20 lymph node tissues. Results : There were 15 girls and 11 boys with a mean age of 13 years. Posterior cervical lymph nodes were involved in 72 percent(18/25) of the patients. Extracervical lymphadenopathy was associated in one patient. Fever was an associated symptom in 31 percent(8/26) of the patients. Leukopenia was observed in six (46 percent) patients. The cervical lymphadenopathy usually resolved spontaneously within 6 months. Only one patient had a recurrence of lymphadenopathy with fever during follow-up. No children with KD in our series developed systemic lupus erythematosus. HHV 8 DNA was not amplified by nested PCR in any of the cases, and all cases were negative for EBV RNA by ISH. Conclusion : KD should be differentiated as a cause of cervical lymphadenopathy in children. HHV 8 and EBV may not play major causative roles in KD in children.

Antibody persistence after Haemophilus influenzae type b (Hib) primary vaccination and response to boosters in Korean children (한국 소아에서 Haemophilus influenzae type b (Hib) 기초 예방 접종 후 항체 지속과 추가 접종에 대한 반응)

  • Lee, Hyunju;Park, So Eun;Lim, Soo Young;Choi, Kyong Min;Lee, Hoan Jong;Kim, Kyung Hyo
    • Clinical and Experimental Pediatrics
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    • v.50 no.5
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    • pp.449-456
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    • 2007
  • Purpose : Antibody persistence after primary series of Haemophilus influenzae type b (Hib) vaccine and responses to a boosters are little known in Korean children. We performed this study to evaluate the antibody titer in relation with a booster immunization of Hib vaccine in Korean children. Methods : One hundred forty-four children aged 12-23 months old were enrolled in three university hospitals. The immunogenicity of a boosters with Hib vaccine was assessed in children previously primed with Hib vaccine. Antibody persistence was also assessed in children who had received 3 doses of Hib vaccine without a booster. Anti-polyribosylribitol phosphate (PRP) IgG antibody levels and bactericidal titers were determined by enzyme immunoassay and bactericidal assay at the Center for Vaccine Evaluation and Study, Medical Research Institute, Ewha Womans University. Results : Prior to a booster in the second year of life, geometric mean antibody concentrations were $2.39{\mu}g/mL$ and the percent of subjects who had a anti-PRP antibody level ${\geq}1{\mu}g/mL$ was 68.6%. After boosting, antibody concentration was $19.09{\mu}g/mL$ and the percent of subjects who had a anti-PRP antibody level ${\geq}1{\mu}g/mL$ was 96.5%, which reflects previous immune priming. In subjects who had finished primary immunization only, the bactericidal titer was 3,946 and in subjects who had a booster, it was 11,205. Anti-PRP antibody level was correlated with serum bactericidal titer. Conclusion : Many children aged 12-23 month old still had protective antibodies after recommended primary immunization only. A booster dose seemed to induce good anamnestic antibody responses in Korean children.

Geochemical characteristics of organic matter in the Tertiary sediments from the JDZ Blocks, offshore Korea (대륙붕 한일공동광구에 분포하는 제 3기 시추 시료 유기물의 지화학적 특성)

  • Lee Youngjoo;Yun Hyesu;Cheong Taejin;Kwak Younghoon;Oh Jaeho
    • The Korean Journal of Petroleum Geology
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    • v.6 no.1_2 s.7
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    • pp.25-36
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    • 1998
  • Organic geochemical analyses were carried out in order to characterize organic matter (OM) in the sediments recovered from Korea/japan Joint Development Zone (JDZ V-1, V-3, VII-1 and VII-2) which is located in the northern end of the East China Sea Shelf Basin. Late Miocene sediments from the JDZ V-1 and V-3 wells generally contain less than $0.5\%$ of total organic carbon (TOC). However, early Miocene and Oligocene sediments show TOC values of $0.6-0.8\%$. Middle to late Miocene sediments are rich in TOC up to $20\%$ from JDZ VII-1 and JDZ VII-2 wells. The reason for this rich TOC might be attributed to the presence of coaly shales. Kerogens in the Tertiary sediments from the JDZ series wells are mainly composed of terrestrially derived woody organic matter. Elemental analyses indicate that OM from these wells can be compared to type III. Low hydrocarbon potential and hydrogen index reflect the type of OM. According to the biomarker analyses, the input of the terrestrial OM is prevalent. Oxidizing condition is also indicated by Pristane/Phytane ratio. Samples from the JDZ V-1 and V-3 wells obtain maturities equivalent to the oil generation zone around total depth, and organic matter below 3600 m from JDZ VII-1 and VII-2 wells reached dry gas generation stage. Oligocene sediments below 3500 m in the JDZ VII-1 and JDZ VII-2 wells may have generated limited amount of hydrocarbons, showing a progressive decrease in hydrogen index with depth, due to thermal degradation with increased burial. Gas shows and finely disseminated gilsonite may indicate the generation and migration of the hydrocarbons.

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