• Title/Summary/Keyword: $T_2$ contrast

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Usefulness Assessment of Automatic Analysis Program for Flangeless Esser PET Phantom Images (Flangeless Esser PET Phantom 영상 자동 분석 프로그램의 유용성 평가)

  • NamGung, Chang-Kyeong;Nam, Ki-Pyo;Kim, Kyeong-Sik;Kim, Jeong-Seon;Lim, Ki-Cheon;Shin, Sang-Ki;Cho, Shee-Man;Dong, Kyung-Rae
    • The Korean Journal of Nuclear Medicine Technology
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    • v.13 no.1
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    • pp.63-66
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    • 2009
  • Purpose: ACR (American College of Radiology) offers variable parameters to PET/CT quality control by using ACR Phantom. ACR Phantom was made to evaluate parameters which are uniformity, attenuation, scatter, contrast and resolution. Manual analysis method wasn't good for the use of QC because values of parameter were changed as it may user and it takes long time to analysis. Ki-Chun Lim, a nuclear scientist in AMC, developed program that automatically analysis values of parameter by using ACR Phantom to overcome above problems. In this study, we evaluated automatic analysis program's usability, through the comparing SUV of each method, reproducibility of SUV when repeated analysis and the time required. Materials and Methods: Using Flangeless Esser PET Phantom, the ideal ratio of 4 : 1 hot cylinder and BKG but it actually showed a ratio of 3.89 to 1 hot cylinder and BKG. SIEMENS Biograph True Point 40 was used in this study. We obtained images using ACR phantom at Fusion WB PET Scan condition (2 min/bed) and 120 kV, 100 mAs CT condition. Using True X method, 3 iterations, 14 subsets, Gaussian filter, FWHM 4 mm and Zoom Factor 1.0, $168{\times}168$ image size. We obtained Max. & Min. SUV and SUV Mean values at Cylinder (8, 12, 16, 25 mm, Air, Bone, Water, BKG) by automatic program and obtained SUV by manual method. After that, we compared manual and automatic method. we estimate the time required from opened the image data to final work sheet was completed. Results: Automatic program always showed same result and same the time required. At 8, 12, 16 and 25 m cylinder, manual method showed 6.69, 3.46, 2.59, 1.24 CV values. The larger cylinder size became, the smaller CV became. In manual method, bone, air, water's CV were over 9.9 except BKG (2.32). Obtained CV of Mean SUV showed BKG was low (0.85) and bone was high (7.52). The time required was 45 second, 882 second respectably. Conclusions: As a result of difference automatic method and manual method, automatic method showed always same result, manual method showed that the smaller hot cylinders became, the lager CV became. Hot cylinders mean region size, the smaller hot cylinder size becomes we had some trouble in doing ROI poison setting. And it means increase in variation of SUV. The Study showed the time required of automatic method was shorten then manual method.

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Spatio-temporal Distributions of Polychaete Communities and Benthic Environmental Characteristics of the Harbor Area of Busan Port, Korea (부산항 주변 저서다모류군집의 시.공간 분포와 저서환경의 특징)

  • Jung, Rae-Hong;Yoon, Sang-Pil;Kim, Youn-Jung;Choi, Min-Kyu;Lee, Won-Chan
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.16 no.3
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    • pp.125-138
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    • 2011
  • This study was conducted to investigate the benthic condition around Busan Port by analysing spatio-temporal distribution pattern of polychaete community and some benthic environmental factors. Field survey was seasonally carried out at 15 stations covering in and outside of Busan Port from February to December, 2007. Water temperature, salinity and the type of surface sediment showed little changes among the stations, but factors related to organic enrichment such as TOC, AVS, coprostanol showed an obvious contrast, especially between in and outside of Busan Port. A total of96 species occurred and mean density was 1,814 ind./$m^2$. Species richness was higher at outer port than inner port, but density was higher at inner port. Dominant species were Aphelochaeta monilaris, Magelona japonica, Pseudopolydora paucibranchiata, etc. and many of them were typical species of organically enriched area. From the multivariate analyses, the whole study area was composed of two distinct polychaete communities located at the inside and outside of the port, and seasonal changes didn't have any influential effects on the structure. Coprostanol and AVS, indicators of organically enriched condition, well explained the community structures of polychaete worms in the vicinity of Busan Port. In this context, the innermost area of North Harbor was in a highly enriched state.

Effect of Nitrite, Thiocyanate and Ascorbic acid on N-nitrosamine Formation in Salted and Dried Yellow Corvenia under Simulated Gastric Digestion (염건조기의 인공소화시 Nitrite, Thiocyanate 및 Ascorbic acid가 N-nitrosamine의 생성에 미치는 영향)

  • 이수정;신정혜;김정균;성낙주
    • Journal of Food Hygiene and Safety
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    • v.15 no.2
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    • pp.101-107
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    • 2000
  • This experiment was conducted to investigate the effect of NA formation in the human body with salted and dried yellow corvenia(Gulbi, Pseudosciaena manchurica) steamed for 30 minutes and incubated in 10 ml simulated saliva and 40 ml gastric juice at 37。C for 2 hours. And the experiment studied the NA formation after nitrite, thiocyanate and ascorbic acid treatment under simulated gastric conditions. N-nitrosodimethylamine(NDMA) was not detected when nitrite was not added to the digestate mixture. And then increasing the nitrite concentration from 0.5 mM to 8 mM gave a slight increase in the NDMA formation at all level of Gulbi utilized in the experiment. In contrast to the change of the nitrite concentration, the increase of the amount of Gulbi didn't show any marked influence on NDMA formation. At all level of thiocyanate(1∼6.4 mM) tested, concentration of NDMA was still proportional to the nitrite concentration. In the catalytic ability of thiocyanate at another high level of nitrite(100 mM) no catalytic activity was observed up to the level of 8mM thiocyanate. The same amounts of salted fish(10 g) and ascorbic acid levels in each single digestate were used to prevent NDMA formation. No prevention effect was observed at nitrite concentration of 0.5 mM and 1 mM. Most importantly, the decrease of NDMA concentration, by the increase of ascorbic acid absolutely, was remarkably shown when nitrite concentration was high. On the contrary, according to the degree of ascorbic acid, the higher the amount of nitrite the higher the prevention of NDMA formation.

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A Study of the Obesity Index and Psychosocial Factors Influencing Obesity among Adolescent Girls (여고생들의 비만도 및 비만과 관련된 사회심리적 요인 분석)

  • 김경원;김영아;김정희
    • Korean Journal of Community Nutrition
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    • v.2 no.4
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    • pp.496-504
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    • 1997
  • The purpose of this study was to investigate the dietary intake, obesity index and psychosocial factors influencing obesity among 200 high school girls in Seoul. The Social Cognitive Theory provided the Conceptual basis for this study. A cross-sectional survey was conducted to examine factors related to obesity, including self-efficacy for controlling overeating, social support for eating behavior, perception of body image and weight control, nutrition knowledge, and attitudes toward obesity. The data were analyzed using t-test and multiple logistic regression. The results of this study are as follows : 1) The mean age of the girls was 16.4 years, and the rate of overweight and obesity(measured by obesity index) was 27.0$\%$. 2) The mean energy intake of subjects was 1832.3$\pm$384.0kcal. The energy derived from carbohydrates, proteins and fats was 62.7$\%$, 13.8$\%$, and 23.5$\%$, respectively. There was no significant difference between the obese and the comparison group in energy intake. 3) The result of multivariate analysis indicated that obesity had a significant relation to the perception of ideal body image, social support for eating behavior, and self-efficacy for controlling overeating(p〈0.01). As subjects preferred thinner body images(OR=0.39) and received less social support(OR=0.93), the odds of being classified as obese increased. The odds of being obese were also associated with self-efficacy, however, the relation was not strong(OR=1.04). 4) Specific social support was related to obesity among adolescent girls. As subjects received more support from family member, the odds of being obese decreased. The emotional support as well as family member's positive nutrition behavior plays a significant role. In addition, instrumental support from friends was associated with obesity. With repect to self-efficacy, the odds of being obese were increased as subjects felt less confident in controlling overeating when tempting food was placed in front of them or after an argument. In contrast, the obese group felt more confident in controlling overeating for the rest of the specific situations examined. These findings suggest that educational interventions for weight control should incorporate strategies to help participants realize their degree of obesity, to reduce the discrepancy between current and ideal body image, to elicit and maintain social support from friends and family, and to increase the self-efficacy for changing eating behaviors. (Korean J Community Nutrition 2(4) : 496-504, 1997)

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A study of image evaluation and exposure dose with the application of Tube Voltage and ASIR of Low dose CT Using Chest Phantom (흉부 Phantom을 이용한 Low Dose CT의 관전압과 ASIR(Adaptive Statistical Iterative Reconstruction)적용에 따른 영상평가 및 피폭선량에 관한 연구)

  • Hwang, Hyeseong;Kim, Nuri;Jeong, Yoonji;Goo, Eunhoe;Kim, Kijeong
    • Korean Journal of Digital Imaging in Medicine
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    • v.16 no.2
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    • pp.9-14
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    • 2014
  • Purpose: The purpose of this study has attempted to evaluate and compare the image evaluation and exposure dose by respectively applying Filtered Back Projection(FBP), the existing test method, and Adaptive Statistical Iterative Reconstruction(ASIR) with different values of tube voltage during the Low Dose Computed Tomography(LDCT). Materials and Methods: With the image reconstruction method as basis, Chest Phantom was utilized with the FBP and ASIR set at 10%, 20% respectively, and the change of Tube Voltage (100kVp, 120kVp). For image evaluation, Back ground noise, Signal to Noise ratio(SNR) and Contrast to Noise ratio(CNR) were measured, and, for dose evaluation, CTDIvol and DLP were measured respectively. The statistical analysis was tested with SPSS(ver. 22.0), followed by ANOVA Test conducted after normality test and homogeneity test. (p<0.05). Results: In terms of image evaluation, there was no outstanding difference in Ascending Aorta(AA) SNR and Infraspinatus Muscle(IM) SNR with the different values of ASIR application(p<0.05), but a significant difference with the different amount of tube voltage(p>0.05). Also, there wasn't noticeable change in CNR with ASIR and different amount of Tube Voltage (p<0.05). However, in terms of dose evaluation, CTDIvol and DLP showed contrasting results(p<0.05). In terms of CTDIvol, the measured values with the same tube voltage of 120kVp were 2.6mGy with No-ASIR and 2.17mGy with 20%-ASIR respectively, decreased by 0.43mGy, and the values with 100kVp were 1.61mGy with No-ASIR and 1.34mGy with 20%-ASIR, decreased by 0.27mGy. In terms of DLP, the measured values with 120kVp were $103.21mGy{\cdot}cm$ with No-ASIR and $85.94mGy{\cdot}cm$ with 20%-ASIR, decreased by $17.27mGy{\cdot}cm$(about 16.7%), and the values with 100kVp were $63.84mGy{\cdot}cm$ with No-ASIR and $53.25mGy{\cdot}cm$ with 20%-ASIR, a decrease by $10.62mGy{\cdot}cm$(about 16.7%). Conclusion: At lower tube voltage, the rate of dose significantly decreased, but the negative effects on image evaluation was shown due to the increase of noise. For the future, through the result of the experiment, it is considered that the method above would be recommended for follow-up patients or those who get health checkup as long as there is no interference on the process of diagnosis due to the characteristics of Low Dose examination.

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Elliptical Centric Techniques and Tricks About the Usefulness of the Clinical Application (Elliptical Centric과 TRICKS 기법의 임상 적용에 관한 유용성 연구)

  • Kim, Sae-Ssak;Goo, Eun-Hoe;Dong, Kyung-Rae;Kweon, Dae-Chel;Lee, Jae-Seung;Cho, Jae-Hwan;Park, Chang-Hee
    • Korean Journal of Digital Imaging in Medicine
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    • v.13 no.2
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    • pp.83-90
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    • 2011
  • To prospectively determine the diagnostic performance a combination of standard bolus-chase magnetic resonance (MR) angiography and MR angiography with time-resolved imaging of contrast kinetics (TRICKS) for depicting severity of the head and neck vascular diseases. Over a period of two months, A total of 100 patients(average ages : $50{\pm}8$, male : 60, female : 40) with head and neck vascular diseases were performed on the GE excite 3.0 T units with 8-channel head coil and 4-channel NV coil. Imaging parameters for a typical study were as follow: SBC(TR/ TE/ FA/ SliceThicken./ Slab/ Freq./ FOV/ BW/Scan Time) = 5.4/ min/ 30/ 2/ zip2/ 70/ $224{\times}448$/ 30/ 62.50/ 28, TRICKS(TR/ TE/ FA/ Slice Thicken/Slab/ Freq./ FOV/ BW/ Temp Res./ Scan Time = 3.6/ min/ 25/ 4/ 30/ $160{\pm}384$, zip512/ 30/ 100/ 1 to 1.5/ 23). The analysis of all MR images, which have respect-ively classified two techniques into some diseases. The results of the former were divided into two groups(SBC, TRICKS)with 4 grading of two reader, respectively. Wilcoxon signed rank test was used to determine if a significant difference between imaging techniques existed(p < 0.05). In 33 of 100 patients, arterio-venous malformation was 11% at TRICKS, subclavian vein stenosis : 8%, fistular sinus : 4%, jugular vein stenosis:6%, Middle Cerebral Artery bypass surgery : 4%, p < 0.05). The rest of 67 patients were considered as the results of SBC(14% in the basilar artery stenosis, carotid stenosis : 16%, vertebral stenosis : 17%, central neuro-cytoma : 5%, meningioma : 5%, Not appliable : 10%, p < 0.05). Sensitivity and specificity of TRICKS MR angiography in SVS, FS, JVS, MCABS were improved compared with those at standard MR angiography. In SBS MR angiography which were improved in BAS, CS, VS, CN, Meningioma. In conclusion, TRICKS MR angiography of the SVS, FS, JVS, MCABS is superior to standard MR angiography regarding the number of diagnostic grading. The SBS MR angiography were improved in BAS, CS, VS, CN, Meningioma. and assessment of the degree of luminal narrowing on both TRICKS and SBS.

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Bioinformatic Analysis of NLS (Nuclear Localization Signals)-containing Proteins from Mollusks (생물정보학을 이용한 연체동물의 NLS (Nuclear Localization Signals) 포함 단백질의 분석)

  • Lee, Yong-Seok;Kang, Se-Won;Jo, Yong-Hun;Gwak, Heui-Chul;Chae, Sung-Hwa;Choi, Sang-Haeng;Ahn, In-Young;Park, Hong-Seog;Han, Yeon-Soo;Kho, Weon-Gyu
    • The Korean Journal of Malacology
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    • v.22 no.2
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    • pp.109-113
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    • 2006
  • Subcellular localization of a protein containing nuclear localization signals (NLS) has been well studied in many organisms ranging from invertebrates to vertebrates. However, no systematic analysis of NLS-containing proteins available from Mollusks has been reported. Here, we describe in silico screening of NLS-containing proteins using the mollusks database that contains 22,138 amino acids. To screen putative proteins with NLS-motif, we used both predict NLS and perl script. As a result, we have found 266 proteins containing NLS sequences which are about 1.2% out of the entire proteins. On the basis of KOG (The eukaryotic orthologous groups) analysis, we can't predict the precise functions of the NLS-containing proteins. However, we found out that these proteins belong to several types of proteins such as chromatin structure and dynamics, translation, ribosomal structure, biogenesis, and signal transduction mechanism. In addition, we have analysed these sequences based on the classes of mollusks. We could not find many from the species that are the main subjects of phylogenetic studies. In contrast, we noticed that cephalopods has the highest number of NLS-containing proteins. Thus, we have constructed mollusks NLS database and added these information and data to the mollusks database by constructing web interface. Taken together, these information will be very useful for those who are or will be studying NLS-containing proteins from mollusks.

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Wind load and wind-induced effect of the large wind turbine tower-blade system considering blade yaw and interference

  • Ke, S.T.;Wang, X.H.;Ge, Y.J.
    • Wind and Structures
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    • v.28 no.2
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    • pp.71-87
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    • 2019
  • The yaw and interference effects of blades affect aerodynamic performance of large wind turbine system significantly, thus influencing wind-induced response and stability performance of the tower-blade system. In this study, the 5MW wind turbine which was developed by Nanjing University of Aeronautics and Astronautics (NUAA) was chosen as the research object. Large eddy simulation on flow field and aerodynamics of its wind turbine system with different yaw angles($0^{\circ}$, $5^{\circ}$, $10^{\circ}$, $20^{\circ}$, $30^{\circ}$ and $45^{\circ}$) under the most unfavorable blade position was carried out. Results were compared with codes and measurement results at home and abroad, which verified validity of large eddy simulation. On this basis, effects of yaw angle on average wind pressure, fluctuating wind pressure, lift coefficient, resistance coefficient,streaming and wake characteristics on different interference zone of tower of wind turbine were analyzed. Next, the blade-cabin-tower-foundation integrated coupling model of the large wind turbine was constructed based on finite element method. Dynamic characteristics, wind-induced response and stability performance of the wind turbine structural system under different yaw angle were analyzed systematically. Research results demonstrate that with the increase of yaw angle, the maximum negative pressure and extreme negative pressure of the significant interference zone of the tower present a V-shaped variation trend, whereas the layer resistance coefficient increases gradually. By contrast, the maximum negative pressure, extreme negative pressure and layer resistance coefficient of the non-interference zone remain basically same. Effects of streaming and wake weaken gradually. When the yaw angle increases to $45^{\circ}$, aerodynamic force of the tower is close with that when there's no blade yaw and interference. As the height of significant interference zone increases, layer resistance coefficient decreases firstly and then increases under different yaw angles. Maximum means and mean square error (MSE) of radial displacement under different yaw angles all occur at circumferential $0^{\circ}$ and $180^{\circ}$ of the tower. The maximum bending moment at tower bottom is at circumferential $20^{\circ}$. When the yaw angle is $0^{\circ}$, the maximum downwind displacement responses of different blades are higher than 2.7 m. With the increase of yaw angle, MSEs of radial displacement at tower top, downwind displacement of blades, internal force at blade roots all decrease gradually, while the critical wind speed decreases firstly and then increases and finally decreases. The comprehensive analysis shows that the worst aerodynamic performance and wind-induced response of the wind turbine system are achieved when the yaw angle is $0^{\circ}$, whereas the worst stability performance and ultimate bearing capacity are achieved when the yaw angle is $45^{\circ}$.

Item-Level Psychometrics of the 12 Items of the Coping Orientation to Problems Experienced Scale (스트레스 대처 척도 12개 항목에 대한 심리측정 속성)

  • Nam, Sanghun;Hilton, Claudia L.;Lee, Mi-Jung;Pritchard, Kevin T.;Bae, Suyeong;Hong, Ickpyo
    • Therapeutic Science for Rehabilitation
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    • v.11 no.3
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    • pp.65-80
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    • 2022
  • Objective : This study examined the psychometric properties of the 12-item Coping Orientation to Problems Experienced Scale (COPE) using Rasch analysis. COPE is one of the instruments used to measure stress-coping skills. Methods : The study participants were 480 community-dwelling older adults. We tested the instrument's unidimensionality assumption using principal component analysis (PCA). Item fit was examined using infit-and-outfit mean-square (MnSq) and standardized fit statistics (ZSTD). The precision and item difficulty hierarchies of the instrument were examined. The item-difficulty hierarchy was investigated to identify the easy and difficult items. We tested differential item functioning (DIF) for sex and age groups. Results : PCA revealed that the instrument met the unidimensionality assumption (eigenvalue = 1.78). Among the 12 items, item 2 was removed because of misfit (Infit MnSq = 1.33, Infit ZSTD = 5.05, Outfit MnSq = 1.56, Outfit ZSTD = 7.15). The remaining 11 items demonstrated a conceptual item-difficulty hierarchy. The person strata value was 3.10, which is equivalent to a reliability index value of 0.81. There was no DIF for the sex and age groups (DIF contrast <0.27). Conclusion : The findings indicated that the revised COPE-11 has adequate item-level psychometric properties and can accurately measure stress coping skills.

Benthic Foraminiferal Assemblage and Sedimentary Environment of Core Sediments from the Northern Shelf of the East China Sea (북동중국해 대륙붕 코아 퇴적물의 저서유공충 군집 특성과 퇴적환경 연구)

  • Kang, So-Ra;Lim, Dhong-Il;Kim, So-Young;Rho, Kyoung-Chan;Yoo, Hae-Soo;Jung, Hoi-Soo
    • Journal of the Korean earth science society
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    • v.29 no.6
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    • pp.454-465
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    • 2008
  • Benthic foraminiferal assemblage and AMS radiocarbon dating of core sediments from the northern shelf of the East China Sea were analyzed in order to understand the paleoenvironment and sedimentary environmental changes around the Korean marginal seas since the last glacial maximum (LGM). The core sediments, containing continuous records of the last 16,000 years, reveal a series of well-defined vertical changes in number of species (S), P/T ratio and species diversity (H) as well as foraminiferal assemblage. Such down-core variations display a sharp change at a core depth of approximately 240 cm, which corresponds to ca. 10,000 year B.P. The sediments of the lower part of the core (240${\sim}$560 cm, Zone I), including the well-developed tide-influenced sedimentary structures, are characterized by high abundances of Ammonia beccarii and Elphidium clavatum (s.l.) and low values in number of species, P/T ratio and diversity. These tide-influenced signatures and foraminiferal assemblage characters suggest that the sediments of Zone I were deposited in a coastal environment (water depths of 20${\sim}$30 m) such as tidal estuary with an influence of the paleo-rivers (e.g., old-Huanghe and Yangtze rivers) during the early phase of the sea-level rise (ca. 16,000 to 10,000 years) since the LGM. In contrast, the upper core sediments (0${\sim}$240 cm, Zone II) are characterized by abundant Eilohedra nipponica and Bolivina robusta with a minor contribution of A. ketienziensis angulata and B. marginata. and high values in number of species, P/T ratio and diversity. Based on relative abundance of these assemblage, Zone II can be divided into two subzones (IIa and IIb). Zone IIa is interpreted to be deposited under the inner-to-middle shelf environment during the marine transgression in the early Holocene (after ca. 9,000 yr B.P.) when sea level rapidly increased. The sediments of zone IIb most likely deposited after 6,000 yr B.P. under the outer shelf environment (80${\sim}$100 m water depth), which is similar to modem depositional environments. The muddy sediments of zone IIb were probably transported from the old-Huanghe and Yangtze Rivers during the late Holocene. We suggest that the present-day oceanographic conditions over the Yellow and the East China Seas have been established after ca. 7,000${\sim}$6,000 yr B.P. when the Kuroshio Current began to influence this area.