• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.3
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• pp.551-560
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• 2011

Recently, There has been increasing concern about WLAN-based indoor positioning system. Most of the existing WLAN-based positioning systems use a fingerprinting method as a main approach. In the fingerprinting approach, the accuracy of the location of a mobile objects is proportional to the number of reference points. However, depending on the increasing number of reference points in the training phase, it requires more time and effort to create fingerprint database. To solve these problems, we propose the new indoor positioning algorithm that calculate the distance between a mobile objects and an AP using the information of surrounding environment WLAN based APs and applied the particle filter to the proposed algorithm in order to improve the accuracy of the estimated location in this paper. To implement this algorithm, at first environmental information database such as wall, iron door, glass door, partition etc. existing in the periphery of the AP should be established. The positioning use attenuation model and path loss model. Our experimental results with proposed algorithm are verified that the positioning accuracy was low but solved the problems with fingerprinting, compared with other positioning algorithms.

• Journal of Yeungnam Medical Science
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• v.10 no.1
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• pp.58-67
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• 1993

The author obtained index of red cell volume distribution width(RDW) and other red cell indices in 210 patients of various hematoncologic conditions and 200 healthy control group using, an automated blood analyzer, Coulter Counter Model S-plus II. This study performed to classify various etiologic anemia based on the MCV and RDW, to evaluate availability to the differential diagnosis in korean anemic distoders somewhat different from etiologies of anemias in foreginers. In the most of cases, the increase or decrease of MCV were always combined the pararell changes of MCH and MCHC. But the values of MCV and RDW were not correlated in control group and patient group. So the terms of heterogenous of homogenous anemia were meaningful morphologic classification than hypochromic or normochromic anemia. The heterogenous microcytic anemia contained iron deficiency anemia. In heterogenous normocytic anemia, myelophthisic anemia, acute leukemia were contained. In heterogenous macrocytic anemia, megaloblastic anemia, hemolytic anemia were contained. The homogenous microcytic anemia was observed in anemia of chronic disorders. In homogenous normocytic anemia, acute blood loss, chronic leukemia, multiple myeloma were contained. The aplastic anemia was belonged to homogenous macrocytic anemia. The diagnostic significance of RDW in hemoglobinopathies is most important. But this study was not contained hemoglobinopathies. Instead RDW was very helpful to differential diagnosis of most common anemias, iron deficiency anemia and anemia due to chronic disorders in Korea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.5
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• pp.570-575
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• 1993

Antioxidative characteristics of melanoidin related products(MRPs) fractionated from fermented soybean sauce were studied during the oxidation process of model systems. MRPs were prepared from soybean sauce fermented for 6 months after inoculation Aspergillus oryzae by the fractionation through the Sephadex G-10 column and the freeze drying of collected fractions. MRPs inhibited the formation of peroxides during the oxidation of linoleic acids mixture in ethanolic phosphate buffer solution at $50^{\circ}C$ with the increasing tendency by their concentration in reaction systems. MRPs had hydrogen doner properties during the reaction with ${\alpha},\;{\alpha}'-diphenyl-{\beta}-picrylhydrazyl$ and also MRPs inhibited the iron and lipoxygenase catalytic oxidation. MRPs were found to be fairly stable with no loss of antioxidative effect after storage at $50^{\circ}C$ for 15days.

• Korean Journal of Clinical Laboratory Science
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• v.41 no.2
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• pp.83-92
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• 2009

This study was undertaken to examine the effect of oxidants on membrane transport function in renal epithelial cells. Hydrogen peroxide ($H_2O_2$) was used as a model oxidant and the membrane transport function was evaluated by measuring $Na^+$-dependent phosphate ($Na^+$-Pi) uptake in opossum kidney (OK) cells. $H_2O_2$ inhibited $Na^+$-Pi uptake in a dose-dependent manner. The oxidant also caused loss of cell viability in a dose-dependent fashion. However, the extent of inhibition of the uptake was larger than that in cell viability. $H_2O_2$ inhibited $Na^+$-dependent uptake without any effect on $Na^+$-independent uptake. $H_2O_2$-induced inhibition of $Na^+$-Pi uptake was prevented completely by catalase, dimethylthiourea, and deferoxamine, suggesting involvement of hydroxyl radical generated by an iron-dependent mechanism. In contrast, antioxidants Trolox, N,N'-diphenyl-p-phenylenediamine, and butylated hydroxyanisole did not affect the $H_2O_2$ inhibition. Kinetic analysis indicated that $H_2O_2$ decreased Vmax of $Na^+$-Pi uptake with no change in the Km value. Phosphonoformic acid binding assay did not show any difference between control and $H_2O_2$-treated cells. $H_2O_2$ also did not cause degradation of $Na^+$-Pi transporter protein. Reduction in $Na^+$-Pi uptake by $H_2O_2$ was associated with ATP depletion and direct inhibition of $Na^+$-$K^+$-ATPase activity. These results indicate that the effect of $H_2O_2$ on membrane transport function in OK cells is associated with reduction in functional $Na^+$-pump activity. In addition, the inhibitory effect of $H_2O_2$ was not associated with lipid peroxidation.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.122-122
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• 2019

Protaetia brevitarsis (PB) extracts has been traditionally used as medicinal stuff to treat blood stasis, occlusion of menstruation, tetanus and liver cancer in Asian countries (Korea, Japan, China, Taiwan, India and Myanmar). Especially, Donguibogam, which is traditional korean medicinal book, described the PB extracts as traditional medicine to treat hepatic diseases and vascular disorders. The PB extracts has been considered as highly nutritional food. The major constituents of PB extracts are rich in protein, healthy fats, iron, calcium. Recent studies announced that PB extracts has hepatoprotective effect and anti-microbacterial effect. However, the effect of PB on ulcerative colitis has not been uncovered yet. The aim of this study was to examine the anti-inflammatory effect of PB extracts in dextran sulfate sodium (DSS)-induced colitis mice model. Cytotoxicity of PB was determined by MTT assay and the antiinflammatory effect of PB extract was investigated by measuring nitric oxide (NO) production. PB extracts did not show any cytotoxicity. AIso, PB extracts supressed NO production in LPS-stimulated mice peritoneal macrophages. To determine whether PB could be an effective treatment on ulcerative colitis, DSS was administered in BALB/c mice for 10 days. PB extract significantly improved the clinical signs of DSS-induced UC, including body weight loss, colon length shortening, and disease activity index increase, with histological markers of colon injury. These findings indicated the possibility of PB as a therapeutic agent on ulcerative colitis.

• Journal of Korea Port Economic Association
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• v.36 no.4
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• pp.17-30
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• 2020

In the shipping industry, it is essential to engage in the preemptive prediction of freight rate volatility through market monitoring. Considering that freight rates have already started to fall, the loss of shipping companies will soon be uncontrollable. Therefore, in this study, factors affecting the freight rates of bulk carriers, which have relatively large freight rate volatility as compared to container freight rates, were quantified and analyzed. In doing so, we intended to contribute to future shipping market monitoring. We performed an analysis using a vector error correction model and estimated the influence of six independent variables on the charter rates of bulk carriers by Handy Size, Supramax, Panamax, and Cape Size. The six independent variables included the bulk carrier fleet volume, iron ore traffic volume, ribo interest rate, bunker oil price, and Euro-Dollar exchange rate. The dependent variables were handy size (32,000 DWT) spot charter rates, Supramax 6 T/C average charter rates, Pana Max (75,000 DWT) spot charter, and Cape Size (170,000 DWT) spot charter. The study examined charter rates by size of bulk carriers, which was different from studies on existing specific types of ships or fares in oil tankers and chemical carriers other than bulk carriers. Findings revealed that influencing factors differed for each ship size. The Libo interest rate had a significant effect on all four ship types, and the iron ore traffic volume had a significant effect on three ship types. The Ribo rate showed a negative (-) relationship with Handy Size, Supramax, Panamax, and Cape Size. Iron ore traffic influenced three types of linearity, except for Panamax. The size of shipping companies differed depending on their characteristics. These findings are expected to contribute to the establishment of a management strategy for shipping companies by analyzing the factors influencing changes in the freight rates of charterers, which have a profound effect on the management performance of shipping companies.

• Korean Chemical Engineering Research
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• v.48 no.2
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• pp.185-192
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• 2010

The chemical-looping combustion(CLC) has advantages of no energy loss for separation of $CO_2$ without $NO_x$ formation. This CLC system consists of oxidation and reduction reactors where metal oxides particles are circulating through these two reactors. In the present study, the reaction kinetic equations of iron oxide oxygen carriers supported on bentonite have been determined by the shrinking core model. Based on the reactivity data, design values of solid circulation rate and solids inventory were determined for the rector. Two types of interconnected fluidized bed systems were designed for CLC application, one system consists of a riser and a bubbling fluidized bed, and the other one has a riser and two bubbling fluidized beds. Solid circulation rates were varied to about $30kg/m^2s$ by aeration into a loop-seal. Solid circulation rate increases with increasing aeration velocity and it increases further with an auxiliary gas flow into the loop-seal. As solid circulation rate is increased, solid hold up in the riser increases. A typical gas leakage from the riser to the fluidized bed is found to be less than 1%.