• ETRI Journal
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• 제42권5호
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• pp.700-711
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• 2020

Because of the rapid increase of mobile traffic, flexible broadband supportive unmanned aerial vehicle (UAV)-based 6G mobile networks using free space optical (FSO) links have been recently proposed. Considering the advancements made in UAVs, big data processing, and artificial intelligence precision control technologies, the formation of an additional wireless network based on UAV aerial platforms to assist the existing fixed base stations of the mobile radio access network is considered a highly viable option in the near future. In this paper, a combined time bound optimization scheme is proposed that can adaptively satisfy the control and communication time constraints as well as the processing time constraints in FSO-based 6G UAV aerial networks. The proposed scheme controls the relation between the number of data flows, input data rate, number of worker nodes considering the time bounds, and the errors that occur during communication and data processing. The simulation results show that the proposed scheme is very effective in satisfying the time constraints for UAV control and radio access network services, even when errors in communication and data processing may occur.

• BMB Reports
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• 제41권7호
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• pp.555-560
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• 2008

The interaction of the rod GTP binding protein, Transducin ($G_t$), with bleached Rhodopsin ($R^*$) was investigated by measuring radiolabeled guanine nucleotide binding to and release from soluble and/or membrane-bound Gt by reconstituting $G_t$ containing bound GDP ($G_t$-GDP) or the hydrolysis-resistant GTP analog guanylyl imidodiphosphate ($G_t$-p[NH]ppG) with $R^*$ under physiological conditions. Release of GDP and p[NH]ppG from $G_t$ occurred to the same extent and with the same light sensitivity both in the presence and absence of added GTP. Significant amounts of $G_t$ without bound nucleotide ($G_{t^-}$) were generated. When ROS containing bleached rhodopsin ($R^*$) were centrifuged in low ionic strength buffer, $G_{t^-}$ remained associated with the membrane fraction, whereas $G_t$-GDP remained in the soluble fraction. These results suggest that $G_t$-GDP and $G_t$-p[NH]ppG have similar affinities for $R^*$. The results also suggest that $G_{t^-}$, rather than $G_t$-GDP, is the moiety which exhibits tight, "light-induced" binding to rhodopsin.

• 복식
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• 제61권7호
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• pp.135-151
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• 2011

The purpose of this study is to research the costume styles during the Silla(新羅), and Paekje dynasty[百濟] in 'Seodong tale'. In those days, costume form, color, pattern, and ornaments played an important role in representing the differences in social status. The Methodology of this study is reviewing and researching the symbolic meaning and classifying the types of the style of the Costume in 'Seodong tale' through the antique records and tombs bequests and expressing the clothing of the appearance people in the picture. This study is about the costume styles representing the differences in social status during the Silla and Baekje dynasty in 'Seodong tale'. Sedong wore 'Heug Geon(黑巾)' and 'Yu', 'Ko(袴)'. The king of Silla, Jinpyung wore Tree and Antler-typed Diadem and 'Po(袍)' with 'GwaDae(銙帶)' and Earrings, Necklaces, Rings. The servant of Baekje wore 'Eunmhwakwansik[silver crown]' and 'Jangyu' bound the silver belt and 'Ko'. Silla Princess of the court, Seonhwa wore Feathered Trim with Conical hat, and 'Yu' bound the belt and 'SangdongChima' and Earrings, Necklaces, Bracelets, Rings. Sedong's mother's hair style was 'Eonjeunmeori' and wore 'Yu' and 'Ko'. The queen of Baeje, Seonhwa wore 'Keumhwasik[Gold crown]', and 'Po' bound the belt and Earrings, Necklaces, Bracelets.

• Advances in materials Research
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• 제3권3호
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• pp.175-183
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• 2014

Natural rubber bound phenolic antioxidant, 2,6-di-tert-butyl-4-vinylphenol (2,6-DBVP), was prepared from natural rubber and 2,6-DBVP in both solution and melt state. The 2,6-DBVP had been synthesized from 3,5-di-tert-butyl-4-hydroxybenzaldehyde and methyltriphenylphosphonium iodide ($MePPh_3I$) by Wittig reaction ($0^{\circ}C$ for 2 hrs, $N_2$ atmosphere). The conditions for preparation of natural rubber bound 2,6-DBVP (NR-DBVP) were optimized for both solution state (1 phr BPO and 8 phr 2,6-DBVP at $70^{\circ}C$ for 2 hrs) and for melt state (1 phr BPO and 8 phr 2,6-DBVP at $70^{\circ}C$ for 10 mins, with rotor speed of 60 rpm). A thermoplastic vulcanizate was obtained using a compatibilizer, polypropylene modified with phenolic resin (PhHRJ-PP), in a closed mixer ($180^{\circ}C$ for 3 mins, rotor speed 60 rpm). The antioxidant properties of vulcanized NR-DBVP, using phenolic as the vulcanization system, were similar to NR with the conventional antioxidant BHT. In addition, the antioxidant, water leaching property of the thermoplastic vulcanizate of NR-DBVP/PP were good in comparison to a NR blend with BHT; the morphologies of these thermoplastic vulcanizates were similar.

• International Journal of Naval Architecture and Ocean Engineering
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• 제7권2호
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• pp.426-434
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• 2015

In this paper we proposed a dada-aided Doppler estimation method for underwater acoustic communication. The training sequence is non-dedicate, hence it can be designed for Doppler estimation as well as channel equalization. We assume the channel has been equalized and consider only flat-fading channel. First, based on the training symbols the theoretical received sequence is composed. Next the least square principle is applied to build the objective function, which minimizes the error between the composed and the actual received signal. Then an iterative approach is applied to solve the least square problem. The proposed approach involves an outer loop and inner loop, which resolve the channel gain and Doppler coefficient, respectively. The theoretical performance bound, i.e. the Cramer-Rao Lower Bound (CRLB) of estimation is also derived. Computer simulations results show that the proposed algorithm achieves the CRLB in medium to high SNR cases.

• ETRI Journal
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• 제33권5호
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• pp.689-694
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• 2011

In this paper, we study scheduling schemes for two-user two-way wireless relaying systems. Two transmission modes are considered: point-to-point direct transmission and two-way amplify-and-forward relaying. An optimal scheduling scheme that opportunistically selects the best transmission mode for each user is proposed to minimize the sum bit error rate (BER). The performance lower bound of the optimal scheduling scheme is analyzed, and closed-form expression of the lower-bound BER is derived. However, for optimal scheduling, the scheduler requires the knowledge of channel state information (CSI) of all links. To reduce the feedback information of CSI, we also propose a suboptimal scheduling scheme that selects the transmission mode using only the CSI of two direct links. Simulation results show that there are 4 dB to 8 dB gains for the proposed optimal and suboptimal schemes over the fixed direct transmission and fixed two-way relayed transmission scheme. The performance gap between the optimal and suboptimal scheduling schemes is small, which implies a good trade-off between implementation complexity and system performance.

• 대한전자공학회논문지SD
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• 제42권10호
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• pp.29-34
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• 2005

최대 양자화 오차는 W 비트 입력으로부터 W 비트의 곱을 출력하는 고정길이 곱셈기의 성능에 많은 영향을 준다. 본 논문에서는 고정길이 modified Booth 곱셈기의 오차범위를 분석한 후 최대오차를 줄이기 위해 추가해야 하는 칼럼 수를 결정하는 방법을 제안한다. 또한, 오차범위 분석방법이 reduced-width 곱셈기 디자인 시에도 적용할 수 있음을 보인다. 시뮬레이션을 통해 제안한 오차분석 방법이 고정길이 modified Booth 곱셈기의 실제 디자인에 유용하게 사용될 수 있음을 보인다.

• 천문학논총
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• 제30권2호
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• pp.321-325
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• 2015

Determining the absolute neutrino mass scale and the neutrino mass hierarchy are central goals in particle physics, with important implications for the Standard Model. However, the final answer may come from cosmology, as laboratory experiments provide measurements for two of the squared mass differences and a stringent lower bound on the total neutrino mass - but the upper bound is still poorly constrained, even when considering forecasted results from future probes. Cosmological tracers are very sensitive to neutrino properties and their total mass, because massive neutrinos produce a specific redshift-and scale-dependent signature in the power spectrum of the matter and galaxy distributions. Stringent upper limits on ${\sum}m_v$ will be essential for understanding the neutrino sector, and will nicely complement particle physics results. To this end, we describe here a series of cosmological hydrodynamical simulations which include massive neutrinos, specifically designed to meet the requirements of the Baryon Acoustic Spectroscopic Survey (BOSS) and focused on the Lyman-${\alpha}$ ($Ly{\alpha}$) forest - also a useful theoretical ground for upcoming surveys such as SDSS-IV/eBOSS and DESI. We then briefly highlight the remarkable constraining power of the $Ly{\alpha}$ forest in terms of the total neutrino mass, when combined with other state-of-the-art cosmological probes, leaving to a stringent upper bound on ${\sum}m_v$.

• Archives of Pharmacal Research
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• 제25권2호
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• pp.158-164
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• 2002

In the course of searching immunomodulators from natural sources, the protein-bound polysaccharide, CM-Ala, has been isolated from the water extract of Chelidonium majus L. (Papaveraceae). The immunostimulatory characteristics have been investigated in several experiments such as generation of activated killer (AK) cells, proliferation of splenocytes, activation of macrophages and granulocyte macrophage-colony forming cell (GM-CFC) assay. Of the fractions obtained using Sephacryl S200 column chromatography, CM-Ala was the most effective fraction that augmented the cytotoxicity against Yac-1 tumor cells from 0.88% to 34.18% by culturing with splenocytes for 5 days. CM-Ala also enhanced nitric oxide production by two fold in peritoneal macrophages and exhibited antitumor activity. It showed mitogenic activity on both spleen cells and bone marrow cells. CM-Ala induced proliferation of splenocytes by 84 fold and increased GM-CFC numbers by 1.48 fold over than the non-treated. On the contrary, CM-Ala had cytotoxic activity to a diverse group of tumor cells. From the above results, we proposed that CM-Ala has a possibility of an effective antitumor immunostimulator.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.537-540
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• 2006

Over the past few decades, a considerable number of studies on the durability of concrete have been carried out extensively. A lot of improvements have been achieved especially in modeling of ionic flows. However, the majority of these researches have not dealt with the chloride binding isotherm based on the mechanism, although chloride binding capacity can significantly impact on the total service life of concrete under marine environment. The purpose of this study is to develop the model of chloride binding isotherm based on the individual mechanism. It is well known that chlorides ions in concrete can be present; free chlorides dissolved in the pore solution, chemical bound chlorides reacted with the hydration compounds of cement, and physical bound attracted to the surface of C-S-H grains. First, sub-model for water soluble chloride content is suggested as a function of pore solution and degree of saturation. Second, chemical model is suggested separately to estimate the response of binding capacity due to C-S-H and Friedel's salt. Finally, physical bound chloride content is estimated to consider a surface area of C-S-H nano-grains and the distance limited by the Van der Waals force. The new model of chloride binding isotherm suggested in this study is based on their intrinsic binding mechanisms and hydration reaction of concrete. Accordingly, it is possible to characterize chloride binding isotherm at the arbitrary stage of hydration time and arbitrary location from the surface of concrete. Comparative study with experimental data of published literature is accomplished to validity this model.