• Proceedings of the IEEK Conference
• /
• 2007.07a
• /
• pp.177-178
• /
• 2007

WiBro system provides reliable broadband communication services for mobile and portable subcribers. It allows interference-free reception under the conditions of multipath propagation and transmission errors. Thus, powerful channel-error correction ability Is required. CC/CTC Decoder which Is mandatory for WiBro system needs lots of computations for real-time operation. So, it is desired to design a CC/CTC Decoder having highly optimized hardware scheme for low latency operation under high data rates. This paper proposes an efficient CC/CTC Decoder structure for high data rate WiBro system. Particularly, the proposed CTC Decoder architecture reduces decoding delay by applying pipelining and multiple decoding blocks. Simulation results show that reduction of about 80% of processing time is enabled with the proposed CC/CTC Decoder despite of increase in are.

• Bulletin of the Korean Chemical Society
• /
• v.28 no.4
• /
• pp.529-532
• /
• 2007

Combined temperature programmed reaction (TPR) and infrared (IR) spectroscopic studies for Fischer- Tropsch reaction have been performed over Ru/SiO2 and Ru-Ag/SiO2 supported catalysts. Reaction of linearly absorbed CO with hydrogen starts at 375 K over Ru/SiO2 catalyst and reaches maximum at 420 K accompanied with an intensity decrease of linear CO absorption. The reaction with bridged absorbed CO peaks around 510-535 K. Addition of Ag yields mixed Ru-Ag bimetallic sites while it suppresses the formation of bridged bonded CO. Formation of methane on this modified surface occurs at 390 K and reaches maximum at 444 K. Suppression of hydrogen on the Ag-doped surface also occurs resulting in the formation of unsaturated hydrocarbons and of CHx intermediates not observed with Ru/SiO2 catalyst. Such intermediates are believed to be the building blocks of higher hydrocarbons during the Fischer-Tropsch synthesis. Linearly absorbed CO is found to be more reactive as compared to bridged CO. The Ag-modified surface also produces CO2 and carbon. On this surface, hydrogenation of CO begins at 390 K and reaches maximum at 494 K. The high temperature for hydrogenation of absorbed CO and C over Ru-Ag/SiO2 catalyst as compared to Ru/SiO2 catalyst is due to the formation of Ru-Ag bimetallic surfaces impeding hydrogen adsorption.

• Molecules and Cells
• /
• v.44 no.9
• /
• pp.688-695
• /
• 2021

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has become a global health concern. Various SARS-CoV-2 vaccines have been developed and are being used for vaccination worldwide. However, no therapeutic agents against coronavirus disease 2019 (COVID-19) have been developed so far; therefore, new therapeutic agents are urgently needed. In the present study, we evaluated several hepatitis C virus direct-acting antivirals as potential candidates for drug repurposing against COVID-19. Theses include asunaprevir (a protease inhibitor), daclatasvir (an NS5A inhibitor), and sofosbuvir (an RNA polymerase inhibitor). We found that asunaprevir, but not sofosbuvir and daclatasvir, markedly inhibited SARS-CoV-2-induced cytopathic effects in Vero E6 cells. Both RNA and protein levels of SARS-CoV-2 were significantly decreased by treatment with asunaprevir. Moreover, asunaprevir profoundly decreased virion release from SARS-CoV-2-infected cells. A pseudoparticle entry assay revealed that asunaprevir blocked SARS-CoV-2 infection at the binding step of the viral life cycle. Furthermore, asunaprevir inhibited SARS-CoV-2 propagation in human lung Calu-3 cells. Collectively, we found that asunaprevir displays broad-spectrum antiviral activity and therefore might be worth developing as a new drug repurposing candidate for COVID-19.

• Journal of the Korea Society of Computer and Information
• /
• v.18 no.4
• /
• pp.35-43
• /
• 2013

As texture images have become prevalent throughout a variety of industrial applications, copyright protection of these images has become important issues. For this reason, this paper proposes a color-texture image watermarking algorithm utilizing texture properties inherent in the image. The proposed algorithm selects suitable blocks to embed a watermark using the energy and homogeneity properties of the grey level co-occurrence matrices as inputs for the fuzzy c-means clustering algorithm. To embed the watermark, we first perform a discrete wavelet transform (DWT) on the selected blocks and choose one of DWT subbands. Then, we embed the watermark into discrete cosine transformed blocks with a gain factor. In this study, we also explore the effects of the DWT subbands and gain factors with respect to the imperceptibility and robustness against various watermarking attacks. Experimental results show that the proposed algorithm achieves higher peak signal-to-noise ratio values (47.66 dB to 48.04 dB) and lower M-SVD values (8.84 to 15.6) when we embedded a watermark into the HH band with a gain factor of 42, which means the proposed algorithm is good enough in terms of imperceptibility. In addition, the proposed algorithm guarantees robustness against various image processing attacks, such as noise addition, filtering, cropping, and JPEG compression yielding higher normalized correlation values (0.7193 to 1).

• Journal of Periodontal and Implant Science
• /
• v.43 no.1
• /
• pp.30-36
• /
• 2013

Purpose: Implant stability at the time of surgery is crucial for the long-term success of dental implants. Primary stability is considered of paramount importance to achieve osseointegration. The purpose of the present study was to investigate the correlation between the insertion torque and primary stability of dental implants using artificial bone blocks with different bone densities and compositions to mimic different circumstances that are encountered in routine daily clinical settings. Methods: In order to validate the objectives, various sized holes were made in bone blocks with different bone densities (#10, #20, #30, #40, and #50) using a surgical drill and insertion torque together with implant stability quotient (ISQ) values that were measured using the Osstell Mentor. The experimental groups under evaluation were subdivided into 5 subgroups according to the circumstances. Results: In group 1, the mean insertion torque and ISQ values increased as the density of the bone blocks increased. For group 2, the mean insertion torque values decreased as the final drill size expanded, but this was not the case for the ISQ values. The mean insertion torque values in group 3 increased with the thickness of the cortical bone, and the same was true for the ISQ values. For group 4, the mean insertion torque values increased as the cancellous bone density increased, but the correlation with the ISQ values was weak. Finally, in group 5, the mean insertion torque decreased as the final drill size increased, but the correlation with the ISQ value was weak. Conclusions: Within the limitations of the study, it was concluded that primary stability does not simply depend on the insertion torque, but also on the bone quality.

• Science of Emotion and Sensibility
• /
• v.25 no.2
• /
• pp.11-22
• /
• 2022

As social beings, we need to understand others' actions as quickly and accurately as possible. Action understanding can occur at many levels. We sometimes grasp others' intentions unintentionally. Other times, however, we have to expend effort to draw inferences about their goals. In the context of joint action, the joint Simon effect demonstrates that actors are influenced by the unintended representation of a co-actor's actions. This effect has been described as quasi-automatic, but it is unclear if the effect is automatic enough to be immune to cognitive load. Thus, we asked participants to complete a joint Simon task with or without a concurrent working memory task. One group of participants maintained a single digit in their mind during working memory load blocks (low-load group), while the other group maintained five digits (high-load group). As a result, the low-load group showed a joint Simon effect both during no-load and low-load blocks. In contrast, the high-load group had no joint Simon effect during either no-load or high-load blocks. These results suggest that the joint Simon effect is not an automatic phenomenon given that it requires cognitive resources. Actors in a joint task may represent a co-actor's actions in their task set, but only when cognitive resources are available.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.12
• /
• pp.3574-3580
• /
• 2009

An embedded motion controller supporting the PLC programming environment based on the IEC 61131-3 International Standard Language was developed in this paper. In this developed motion controller, the CoDeSys, one of the IEC61131-3 development tools, was embedded in order to support that of PLC as well as the development environment of the PC, and the various function blocks based on PLCopen standard for motion control such as the linear and circular interpolation control were implemented. Moreover, the ethernet based remote control on real-time operating system and the motion simulator for a motion programmer were implemented.

• Journal of Korean Society of Forest Science
• /
• v.4 no.1
• /
• pp.14-16
• /
• 1965

(1) The sterilizing effects of NaF, $CuSO_4$, $CuCO_3$, $HgCl_2$, $ZnSO_4$, and coaltar creosote on the mycelial growth of Irpex consors Berk. Polystictus versicolor L. Fr, Polystictus versicalor L. var. nigricans, and Schizophyllum commune Fr. Were studied. (2) The range of minimum density of the fungicides to check the growth of four fungi mentioned above was as follows; NaF 0.15~0.25(%) $CuSO_4$ 0.20~0.35(%) $CuCO_3$ 0.40~0.50(%) $HgCl_2$ 0.05(%) $ZnSO_4$ 0.40~0.45(%) Creosote 0.10~0.15(%) Of the fungicides tested, $HgCl_2$ was most effective in fungicidal effects, and Creosote, NaF, $CuSO_4$, $ZnSO_4$, $CuCO_3$, followed. The order of resistance of the fungi to the fungicides was as follows: S. Commune Fr. P. Versicalor L. var.nigricans I. Consors Berk P. Versicalor L. Fr. (3) The fungicides were added to the pepton-agor culture medium at the concentration between 0.01 and 0.5%, and the medium was filled into 9cm petridshes. Two square millimeter agar blocks prepared separately from the fungi Contained agar were placed in the middle of the Petri-dishes, in cubated six days at $26^{\circ}C$. Diameter of biggest Colonies were measured.

• Special Issue of the Society of Naval Architects of Korea
• /
• 2008.09a
• /
• pp.118-125
• /
• 2008

The deck plates of ship block is made of thin plates in their construction. A main reason of using thin plates is that deck plates don't need to support large structural loads. Therefore, out-of-plane deformations between stiffeners are frequent in deck blocks. Because these are got right by correction heating, they continuously causes quality problems in the final dock-building process. According to preceding research, the lifting process by cranes would offset the effect of correction heating. This study finds out the remained efficiency of correction heating when tensional loads are added by a lifting to corrected parts. We used inherent strains in calculating the efficiency, and established the methodology where the positions for callings are. For getting more accurate positions, besides the structural lifting analysis, welding deformation analysis with upper block and measured data from a serial ship are also referenced.

• Restorative Dentistry and Endodontics
• /
• v.44 no.3
• /
• pp.23.1-23.9
• /
• 2019

Objectives: The aim of this study was to investigate the microshear bond strength (${\mu}SBS$) of different universal adhesive systems applied to hybrid computer-aided design/computer-aided manufacturing (CAD-CAM) restorative materials repaired with a composite resin. Materials and Methods: Four types of CAD-CAM hybrid block materials-Lava Ultimate (LA), Vita Enamic (VE), CeraSmart (CS), and Shofu Block HC (SH)-were used in this study, in combination with the following four adhesive protocols: 1) control: porcelain primer + total etch adhesive (CO), 2) Single Bond Universal (SB), 3) All Bond Universal (AB), and 4) Clearfil Universal Bond (CU). The ${\mu}SBS$ of the composite resin (Clearfil Majesty Esthetic) was measured and the data were analyzed using two-way analysis of variance and the Tukey test, with the level of significance set at p < 0.05. Results: The CAD-CAM block type and block-adhesive combination had significant effects on the bond strength values (p < 0.05). Significant differences were found between the following pairs of groups: VE/CO and VE/AB, CS/CO and CS/AB, VE/CU and CS/CU, and VE/AB and CS/AB (p < 0.05). Conclusions: The ${\mu}SBS$ values were affected by hybrid block type. All tested universal adhesive treatments can be used as an alternative to the control treatment for repair, except the AB system on VE blocks (the VE/AB group). The ${\mu}SBS$ values showed variation across different adhesive treatments on different hybrid CAD-CAM block types.