• Journal of Ecology and Environment
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• v.38 no.3
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• pp.307-318
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• 2015

The objectives of this study were to identify multi-level stressors from blood biomarkers to community-level bioindicators and diagnose the stream ecosystem health in polluted streams. Blood chemistry such as total protein ($T_{Pro}$), blood urea nitrogen ($B_{UN}$), total cholesterol ($T_{Cho}$) and $A_{lb}$umin ($A_{lb}$) were analyzed from sentinel fish tissues; the functions of kidney, gill and liver were significantly decreased in the impacted zone ($I_z$), compared to the control zone ($C_z$). Histopathological analysis showed that fish liver tissues were normal in the $C_z$. Fish liver tissues in the $I_z$, however, showed large cell necrosis and degeneration and also had moderate lobular inflammation and inflammatory cell infiltration of lymphocytic histocytes. Species biotic index (SBI) at species level and stream health assessment (SHA) at community level indicated that chemical impacts were evident in the $I_z$ (ecological health; poor - very poor), and this was matched with the blood tissue analysis and histopathological analysis. The impairments of the streams were supported by water chemistry analysis (nitrogen, phosphorus). Tolerance guild analysis and trophic guild analysis of fish were showed significant differences (P < 0.01) between $C_z$ and $I_z$. Overall, multiple parameter analysis from biomarker level (blood tissues) to bioindicator level (community health) showed significantly greater impacts in the $I_z$ than $C_z$. This approach may be effective as a monitoring tool in identifying the multilateral and forthcoming problems related to chemical pollution and habitat degradation of stream ecosystems.

• Parasites, Hosts and Diseases
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• v.55 no.5
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• pp.505-512
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• 2017

Toxoplasma gondii cathepsin C proteases (TgCPC1, 2, and 3) are important for the growth and survival of T. gondii. In the present study, B-cell and T-cell epitopes of TgCPC1 were predicted using DNAstar and the Immune Epitope Database. A TgCPC1 DNA vaccine was constructed, and its ability to induce protective immune responses against toxoplasmosis in BALB/c mice was evaluated in the presence or absence of the adjuvant ${\alpha}-GalCer$. As results, TgCPC1 DNA vaccine with or without adjuvant ${\alpha}-GalCer$ showed higher levels of IgG and IgG2a in the serum, as well as IL-2 and $IFN-{\gamma}$ in the spleen compared to controls (PBS, pEGFP-C1, and ${\alpha}-GalCer$). Upon challenge infection with tachyzoites of T. gondii (RH), $pCPC1/{\alpha}-GalCer$ immunized mice showed the longest survival among all the groups. Mice vaccinated with DNA vaccine without adjuvant (pCPC1) showed better protective immunity compared to other controls (PBS, pEGFP-C1, and ${\alpha}-GalCer$). These results indicate that a DNA vaccine encoding TgCPC1 is a potential vaccine candidate against toxoplasmosis.

• Journal of the Korean Association of Geographic Information Studies
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• v.5 no.3
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• pp.33-44
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• 2002

The water resources information system of a watershed should be set up to understand the water management problems with reflecting basin characteristics for the effective water use. This study is to develop a watershed management system to be operated in water resources and water quality management. In order to promote effective utilization of this system, the various kinds of information data are collected, and this system could be utilized as a valuable tool for maximum uses of them. The information system developed in this study is constructed with GUI(graphic user interface) system using Arc-View and Visual Basic at the circumstances based on the PC. The integrated GIS and Remote Sensing based system is directed to the need for more detailed information on watershed management. The ability to present system clearly provides an indispensable tool for a river basin development and water management plan.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.4
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• pp.139-149
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• 2003

In this paper a hardware design of area-efficient hash processor which implements MD5 algorithm using hardware sharing and carry-save addition schemes is described. To reduce area, the processor adopts hardware sharing scheme in which 1 step operation is divided into 2 substeps and then each substep is executed using the same hardware. Also to increase clock frequency, three serial additions of substep operation are transformed into two carry-save additions and one carry propagation addition. The MD5 hash processor is designed using 0.25 $\mu\textrm{m}$CMOS technology and consists of about 13,000 gates. From timing simulation results, the designed MD5 hash processor has 465 Mbps hash rates for 512-bit input message data under 120 MHz operating frequency.

• Korean Journal of Radiology
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• v.22 no.3
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• pp.415-424
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• 2021

Objective: To determine whether noncontrast computed tomography (NCCT) models based on multivariable, radiomics features, and machine learning (ML) algorithms could further improve the discrimination of early hematoma expansion (HE) in patients with spontaneous intracerebral hemorrhage (sICH). Materials and Methods: We retrospectively reviewed 261 patients with sICH who underwent initial NCCT within 6 hours of ictus and follow-up CT within 24 hours after initial NCCT, between April 2011 and March 2019. The clinical characteristics, imaging signs and radiomics features extracted from the initial NCCT images were used to construct models to discriminate early HE. A clinical-radiologic model was constructed using a multivariate logistic regression (LR) analysis. Radiomics models, a radiomics-radiologic model, and a combined model were constructed in the training cohort (n = 182) and independently verified in the validation cohort (n = 79). Receiver operating characteristic analysis and the area under the curve (AUC) were used to evaluate the discriminative power. Results: The AUC of the clinical-radiologic model for discriminating early HE was 0.766. The AUCs of the radiomics model for discriminating early HE built using the LR algorithm in the training and validation cohorts were 0.926 and 0.850, respectively. The AUCs of the radiomics-radiologic model in the training and validation cohorts were 0.946 and 0.867, respectively. The AUCs of the combined model in the training and validation cohorts were 0.960 and 0.867, respectively. Conclusion: NCCT models based on multivariable, radiomics features and ML algorithm could improve the discrimination of early HE. The combined model was the best recommended model to identify sICH patients at risk of early HE.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.5
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• pp.2291-2295
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• 2014

Although nucleolar protein nucleostemin (NS) is essential for cell proliferation and early embryogenesis and expression has been observed in some types of human cancer and stem cells, the molecular mechanisms involved in mediation of cell proliferation and cell cycling remains largely elusive. The aim of the present study was to evaluate NS as a potential target for gene therapy of human breast carcinoma by investigating NS gene expression and its effects on SKBR-3 cell proliferation and apoptosis. NS mRNA and protein were both found to be highly expressed in all detected cancer cell lines. The apoptotic rate of the pcDNA3.1-NS-Silencer group ($12.1-15.4{\pm}3.8%$) was significantly higher than those of pcDNA3.1-NS ($7.2-12.0{\pm}1.7%$) and non-transfection groups ($4.1-6.5{\pm}1.8%$, P<0.01). MTT assays showed the knockdown of NS expression reduced the proliferation rate of SKBR-3 cells significantly. Matrigel invasion and wound healing assays indicated that the number of invading cells was significantly decreased in the pcDNA3.1-NS-siRNA group (P<0.01), but there were no significant difference between non-transfected and over-expression groups (P>0.05). Moreover, RNAi-mediated NS down-regulation induced SKBR-3 cell G1 phase arrest, inhibited cell proliferation, and promoted p53 pathway-mediated cell apoptosis in SKBR-3 cells. NS might thus be an important regulator in the G2/M check point of cell cycle, blocking SKBR-3 cell progression through the G1/S phase. On the whole, these results suggest NS might be a tumor suppressor and important therapeutic target in human cancers.

• Journal of KIISE:Information Networking
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• v.33 no.2
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• pp.175-182
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• 2006

The CGA proposed by IETF working group prevents address spoofing and stealing and provides digital signature to users, but key collision problem arises. To solve this critical problem, the CGA defines the SEC field within address format, which is set to high value when high security is required and vice versa, but the CGA faces a dilemma between security and the processing time. As SEC value increases, the processing time to generate the CGA grows dramatically while key collision ratio increases if low SEC value is applied to the CGA. We propose modified CGA (MCGA) that has shorter processing time than the CGA and offers digital signature with small overheads. To solve key collision problem, we employ hierarchical ad hoc network. The MCGA is applicable to IPv6 networks as well public networks. In this paper, we design a mathematical model to analyze the processing time for MCGA and CGA first and evaluate the processing time via simulations, where the processing time for MCGA is reduced down 3.3 times when SEC value is set to 0 and 68,000 times when SEC value is set to 1. Further, we have proved that the CGA is inappropriate for both ad hoc networks and IPv6 networks when the SEC field is set to more than 3.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.1
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• pp.107-118
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• 2003

The purpose of this study is to assess the hydrological impact on a watershed from long-term land cover changes. Gyeongan-cheon watershed($558.2km^2$) was selected and WMS(watershed modeling system) HEC-1 model was adopted as an evaluation tool. To identify land cover changes, five Landsat images(1980/2/15, 1986/4/15, 1990/4/26, 1996/4/26, 2000/5/17) were selected and analyzed using maximum likelihood method. As a result, urban areas have increased by 5.6% and forest areas have decreased by 6.1% between 1980 and 2000. SCS curve number increased by 9.8. To determine model parameters and evaluate HEC-1 model, five storm events(1998/5/2, 1998/8/23, 1998/9/30, 1999/5/3, 2000/7/29) were used. The simulated stream flow agreed well with the observed one with relative errors ranging from 9% to 36%. For 254 mm daily rainfall of 30 years frequency, due to the increase of urban areas peak flow increased by $455m^3/sec$ and the time of peak flow reduced about four hours for 20 years land cover changes.

• Health Policy and Management
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• v.33 no.3
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• pp.243-252
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• 2023

This paper aims to introduce Korea's total current health expenditure (CHE) and National Health Accounts of the year 2021 and their 2022 preliminary figures constructed on the basis of the System of Health Accounts 2011. As CHE includes expenditures for prevention, tracking, and treatment of coronavirus disease 2019 (COVID-19) and compensation for losses to medical institutions from 2020, the details are also introduced. Korea's total CHE in 2021 is 193.3 trillion won, which is 9.3% of gross domestic product (GDP). The preliminary figure in 2022, 209.0 trillion won, exceeded the 200 trillion won line for the first time, and its "ratio to GDP" of 9.7% is expected to exceed the average of Organisation for Economic Co-Operation and Development member countries for the first time. Korea's health expenditures, which were well controlled until the end of the 20th century, have increased at an alarming rate since the beginning of the 21st century, threatening the sustainability of national health insurance. The increase in health expenditure after 2020 is partly due to a temporary increase in response to COVID-19. However, when considering the structure of Korea's health insurance price hike, where the ratchet effect of increased medical expenses works particularly strongly, it is unlikely that the accelerating growth trend that has lasted for more than 20 years will stop easily. More aggressive policies to control medical expenses are required in the national health insurance which not only constitutes the main financing sources of the Korean health system but also has the most powerful policy means in effect for changes in the health care provision.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.12
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• pp.53-60
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• 2005

This work proposes a 10b 100 MS/s $1.4\;mm^2$ CMOS ADC for low-power multimedia applications. The proposed two-step pipeline ADC minimizes chip area and power dissipation at the target resolution and sampling rate. The wide-band SHA employs a gate-bootstrapping circuit to handle both single-ended and differential inputs with 1.2 Vp-p at 10b accuracy while the second-stage flash ADC employs open-loop offset sampling techniques to achieve 6b resolution. A 3-D fully symmetrical layout reduces the capacitor and device mismatch of the first-stage MDAC. The low-noise references are integrated on chip with optional off-chip voltage references. The prototype 10b ADC implemented in a 0.18 um CMOS shows the maximum measured DNL and INL of 0.59 LSB and 0.77 LSB, respectively. The ADC demonstrates the SNDR of 54 dB, the SFDR of 62 dB, and the power dissipation of 56 mW at 100 MS/s.