• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10C
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• pp.995-1006
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• 2003

It is well know that in the wireless communication systems the transmitted signals can suffer from multipath fading due to the wave propagation characteristics and the obstacles over the paths, resulting in serious reduction in the power of the received signals. However, it is possible to take advantage of the inherent diversity imposed in the multipath reception if the underlying channel can be properly estimated. One of the diversity reception methods in this case is Rake processing. In this paper we study the Rake receivers for the direct-sequence spread-spectrum communication systems utilizing PN (pseudo noise) sequences to achieve spread spectrum. A conventional Rake receiver can use the finite-duration impulse (FIR) filter followed by the PN sequence demodulator, where the FIR filter coefficients are the reverse-ordered complex conjugate values of the fading channel impulse response estimates. Here, we propose a new Rake processing method by replacing the aforementioned PN code sequence with a new set of optimum demodulator coefficients. More specifically, the concept of the new optimum Rake processing is first introduced and then the optimum demodulator coefficients are theoretically derived. The performance obtained using the new optimum Rake processing is also calculated. The analytical results are verified by computer simulation. As a result, it is shown that the new optimum Rake processing method improves the MSE performance more than 10 dB over the conventional one using the fixed PN sequence demodulator. It is also shown that the new optimum Rake processing method improves the MSE performance about 10 dB over the Adaptive Correlator that performs the combining of the multipath components and PN demodulation concurrently. And finally, the MSE performance of the optimum Rake demodulator is very close to the MSE performance of OPSK demodulator under the AWGN channel.

• Korean Journal of Weed Science
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• v.18 no.2
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• pp.161-170
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• 1998

Antagonistic mode of action of fenoxaprop-P-ethyl [ethyl(R)2-4-{(6-chloro-2-benzoxazolyloxy) phenoxy}propionate] with bentazon was investigated with respect to absorption, translocation, metabolism, and change in target site response of fenoxaprop-P-ethyl using four-leaf stage of rice(Oryza sativa L.) and barnyardgrass [Echinochloa eras-galli (L.) P. Beauv.]. Shoots of rice and barnyardgrass was more sensitive to fenoxaprop-P-ethyl than the roots. More than 90% of fenoxaprop-P-ethyl was absorbed within 6 hours after treatment and 30% of the absorbed was acropetally and basipetally translocated at 24 hours after treatment. Fenoxaprop-P-ethyl was rapidly transformed to its acid form, fenoxaprop(2-[4-(6-chloro-2-benzoxazolyloxy)phenoxy]propionic acid), which was subsequently metabolized to polar conjugates. However, changes in absorption, translocation, and metabolism of fenoxaprop-P-ethyl by bentazon treatment were not found in both species. Background activity of acetyl-CoA carboxylase(ACCase) in rice and barnyardgrass was 26.5 and 23.2nmol/min/mg, respectively. Concentration required to inhibit fifty percent enzyme activity$(I_{50})$ in vitro was 6.5~7.4${\mu}M$ of fenoxaprop-P-ethyl and more than 500${\mu}M$ of bentazon. There were no significant differences in $I_{50}$ value between two treatments of fenoxaprop-P-ethyl alone and its bentazon mixture. However, bentazon reduced ACCase activity in vivo and inhibited electron transport in chloroplast thylakoid. Based on the results obtained, it is concluded that the antagonistic effect of bentazon occurs due not to direct effect on target site of fenoxaprop-P-ethyl, but to indirect involvement in reducing herbicidal activity of fenoxaprop-P-ethyl through physiological disturbances caused by bentazone at whole chloroplast level.

• Parasites, Hosts and Diseases
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• v.25 no.1
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• pp.1-6
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• 1987

This study was to observe the changes of blastogenic responses of splenic Iymphocytes to T-cell mitogens, N. fcwleri Iysate and concanaualin A, and serum antibody titer during the course of experimental PAM in mice. Naegleria fcwleri, strain 0359, was cultured in the CGVS medium axenically and inoculated intranasally with $7{\times}10^4$ trophozoites for the development of experimental PAM in mice. The amoebae were subjected to ultrasonication and centrifuged at 20,000g for 60 minutes, and filtered through $0.2{\mu\textrm{m}}$ filter membrane. The supernatant, N. fcwleri Iysate, was used as T-cell mitogen, and antigen for ELISA. The serum antibody was examined by ELISA using peroxidase conjugate. Two hundred ${\mi}l$ of $10^6$ splenocytes in RPMI 1640 containing 0% fetal calf serum were added to each well of a microtiter plate. To each well was added T-cell mitogens, $100{\mu}g/ml$ of N. fowleri Iysate or $4{\mu}g/ml$ of con. A, and the plates were incubated for 42 hours at $37^{\circ}C$ in 5% $CO_2$ incubator. Cultures were pulsed with of $methyl-(^3H)-thymidine$ 6 hour before harvesting. The mean blastogenic response of the splenocytes to N. fewleri Iysate was reduced, whereas that to con. A was also reduced up to on day 11 after infection. Both of these results were statistically significant compared with those of uninfected control group. The serum antibody titers were increased gradually up to day 15. The results indicated that there was an impairment of the blastogenic response of splenocytes to N. fowleri Iysate during the acute course of experimental PAM in mice.

• Korean Journal of Remote Sensing
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• v.14 no.3
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• pp.250-261
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• 1998

The purpose of this paper is to extract fast DEM (Digital Elevation Model) using satellite images. DEM extraction consists of three parts. First part is the modeling of satellite position and attitude, second part is the matching of two images to find corresponding points of them and third part is to calculate the elevation of each point by using the results of the first and second part. The position and attitude modeling of satellite is processed by using GCPs. A area based matching method is used to find corresponding points between the stereo satellite images. The elevation of each point is calculated using the exterior orientation parameters obtained from modeling and conjugate points from matching. In the DEM generation system, matching procedure holds most of a processing time, therefore to reduce the time for matching, a new fast matching algorithm using gradient correlation and fast similarity measure calculation method is proposed. In this paper, the SPOT satellite images, level 1A 6000$\times$6000 panchromatic images are used to extract DEM. The experiment result shows the possibility of fast DEM extraction with the satellite images.

• Geophysics and Geophysical Exploration
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• v.8 no.1
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• pp.18-25
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• 2005

We derive refraction statics for seismic data recorded in a hard rock terrain, in which there are large and rapid variations in the depth of weathering. The statics corrections range from less than 10 ms to more than 70 ms, often over distances as short as 12 receiver intervals. This study is another demonstration of the importance in obtaining accurate initial refraction models of the weathering in hard rock terrains in which automatic residual statics may fail. We show that the statics values computed with a simple model of the weathering using the Generalized Reciprocal Method (GRM) and the Refraction Convolution Section (RCS) are comparable in accuracy to those computed with a more complex model of the weathering, using least-mean-squares inversion with the conjugate gradient algorithm (Taner et al., 1998). The differences in statics values between the GRM model and that of Taner et al. (1998) systematically vary from an average of 2ms to 4ms over a distance of 8.8 km. The differences between these two refraction models and the final statics model, which includes the automatic residual values, are generally less than 5 ms. The residuals for the GRM model are frequently less than those for the model of Taner et al. (1998). The RCS statics are picked approximately 10 ms later, but their relative accuracy is comparable to that of the GRM statics. The residual statics values show a general correlation with the refraction statics values, and they can be reduced in magnitude by using a lower average seismic velocity in the weathering. These results suggest that inaccurate average seismic velocities in the weathered layer may often be a source of short-wavelength statics, rather than any shortcomings with the inversion algorithms in determining averaged delay times from the traveltimes.

• Journal of Applied Biological Chemistry
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• v.64 no.4
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• pp.343-349
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• 2021

The rhizomes of Cnidium officinalis were extracted in aqueous MeOH, and the concentrate was fractionated via systematic solvent fractionation to EtOAc, n-BuOH, and aqueous fractions. The repeated column chromatography of EtOAc and n-BuOH fractions using silica gel, octadecyl silica gel, and Sephadex LH-20 as stationary phase to afford five lipids. They were identified to be methyl linoleate (1), linoleic aicd (2) 6-linoleoyl-𝛼-D-glucopyranosyl 𝛽-D-fructofuranoside (3), 1-linolenoyl-3-(𝛼-D-galactopyranosyl (1→6)-𝛽-D-galactopyranosyl) glycerol (4), and 1-linoleoyl-3-(𝛼-D-galactopyranosyl (1→6)-𝛽-D-galactopyranosyl) glycerol (5) on the basis of spectroscopic data such as IR, MS, and Nuclear magnetic resonance (NMR). Compounds 1 and 3-5 were isolated for the first time from this plant in this study. The NMR data of fatty acids 1 and 2 reported in literatures are different each other. Authors identified the NMR data without ambiguity. Compound 3, a conjugate of sucrose and fatty acid, and compounds 4 and 5, digalactosyl monoglyceride, are very rarely occurred in natural source. Through the immune enhancement and anticancer activity of the reported lipid compounds, the potential as various pharmacologically active materials of Cnidium officinalis rhizome can be expected.

• BMB Reports
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• v.52 no.8
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• pp.496-501
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• 2019

Conventionally, immunotoxins have been produced as a single polypeptide from fused genes of an antibody fragment and a toxin. In this study, we adopted a unique approach of chemical conjugation of a toxin protein and an antibody fragment. The two genes were separately expressed in Escherichia coli and purified to high levels of purity. The two purified proteins were conjugated using a chemical linker. The advantage of this approach is its ability to overcome the problem of low recombinant immunotoxin production observed in some immunotoxins. Another advantage is that various combinations of immunotoxins can be prepared with fewer efforts, because the chemical conjugation of components is relatively simpler than the processes involved in cloning, expression, and purification of multiple immunotoxins. As a proof of concept, the scFv of trastuzumab and the PE24 fragment of Pseudomonas exotoxin A were separately produced using E. coli and then chemically crosslinked. The new immunotoxin was tested on four breast cancer cell lines variably expressing HER2. The chemically crosslinked immunotoxin exhibited cytotoxicity in proportion to the expression level of HER2. In conclusion, the present study revealed an alternative method of generating an immunotoxin that could effectively reduce the viability of HER2-expressing breast cancer cells. These results suggest the effectiveness of this method of immunotoxin crosslinking as a suitable alternative for producing immunotoxins.

• The Journal of Engineering Geology
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• v.28 no.4
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• pp.645-660
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• 2018

In the southeastern part of the Korean Peninsula, huge fault valleys, including the Yangsan and Ulsan faults, are recognized. These NNE-SSW trending lineaments are called as a whole Yangsan Fault System. However, this fault system is relatively poorly studied except the Yangsan and Ulsan faults. This study deduced the paleostress history based on the mutual cross-cutting relationships between geologic structures developed in the granite body near the Ilgwang fault, which is compared with previous studies. In the study area, four lineaments parallel to the Ilgwang fault are recognized, and three of them show evidences of faulting. In each lineament, both slip-senses of left-lateral and right-lateral are recognized. It indicates that these faults consistently underwent multiple deformations of inversion along the faults. The inferred paleostress directions based on the mutual cross-cutting relationships of the geological structures are as follows: 1) Tensile fractures developed in the late Cretaceous under the ENE-WSW direction of compressive stress, 2) NW-SE trending maximum horizontal principal stress generated conjugate strike-slip faults, and 3) selective reactivations of some structures were derived under the compression by the NE-SW trending principal stress.

• Applied Chemistry for Engineering
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• v.22 no.6
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• pp.599-604
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• 2011

In this study, we investigated the efficacy of ${\beta}$-cyclodextrin (${\beta}CD$) hydrorogel containing silk fibroin (SF) on healing burnt wound. Tosyl ${\beta}CD$ was conjugated to polyethyleneimine (PEI) using epichlorohydrin (EPI) as a cross-linker. The ${\beta}CD/PEI/SF$ hydrogel was applied on the back of mouse and then the efficacy of hydrogel was compared with both positive control group and negative control group. There was no wound healing efficacy showed neither in the drug loaded ${\beta}CD/PEI/SF$ hydrogel group nor in the drug unloaded ${\beta}CD/PEI/SF$ hydrogel group. On the other hand, in the positive control group, a significant reduction of the wound size after the usage of OTC hydrorogel was obtained. The burn-healing histological result showed a similar phenomenon. After hematoxylin-eosin staining the skin induced by burning, and the epithelial growth observed in the dermis, the efficacy of ${\beta}CD/PEI/SF$ hydrogel in healing burnt wound could not be clearly identified.

• Applied Chemistry for Engineering
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• v.35 no.2
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• pp.67-78
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• 2024

Light absorption has potential as a signal in biochemical analyses due to its simplicity in measurement and interpretational clarity. Among substances that generate absorption signals, gold nanoparticles possess advantages such as chemical stability, biological compatibility, and unique optical properties from the localized surface plasmon resonance (LSPR) in the visible light range. They also exhibit versatility compared to other colorimetric substances effective only for specific target molecules, as they easily conjugate with various detection active substances like antibodies and aptamers. Particularly due to advantages such as low cost, ease of particle synthesis, and high environmental stability compared to enzyme-based colorimetric methods, gold nanoparticles are extensively researched as signal substances in colorimetric assays. This review summarizes various strategies utilizing gold nanoparticles as absorption signal substances, focusing on recent research. Based on the characteristics of gold nanoparticles, where the optical property is influenced by particle morphology, literature is classified and reviewed based on strategies controlling the shape of gold nanoparticles during signal generation. Through this, it is observed that gold nanoparticles, which have been used as absorption signal substances, continue to be actively researched, affirming their potential for broad and continuous improvement in the future.