• Journal of the Korean Society for Nondestructive Testing
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• v.3 no.1
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• pp.31-35
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• 1983

AE technology developments directed at nuclear power plant application are reviewed and related activities in Korea are also briefly introduced.

• Proceedings of the KIEE Conference
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• 1997.07e
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• pp.1678-1680
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• 1997

The pulsed power with the high voltage and current can be used to the fields of high speed pulses of energy in different forms such as electric current and voltage, electron beam, ion beam, x-rays, gamma rays, heat, magnetics fields, sound and shock waves. This paper is directed mainly at electrical engineers working on production and practical application of high speed pulsed power with high voltage and current.

• BMB Reports
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• v.40 no.5
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• pp.697-707
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• 2007

Cytochrome $cbb_3$ oxidase is a member of the heme-copper oxidase superfamily that catalyses the reduction of molecular oxygen to the water and conserves the liberated energy in the form of a proton gradient. Comparison of the amino acid sequences of subunit I from different classes of heme-copper oxidases showed that transmembrane helix VIII and the loop between transmembrane helices IX and X contain five highly conserved polar residues; Ser333, Ser340, Thr350, Asn390 and Thr394. To determine the relationship between these conserved amino acids and the activity and assembly of the $cbb_3$ oxidase in Rhodobacter capsulatus, each of these five conserved amino acids was substituted for alanine by site-directed mutagenesis. The effects of these mutations on catalytic activity were determined using a NADI plate assay and by measurements of the rate of oxygen consumption. The consequence of these mutations for the structural integrity of the $cbb_3$ oxidase was determined by SDS-PAGE analysis of chromatophore membranes followed by TMBZ staining. The results indicate that the Asn390Ala mutation led to a complete loss of enzyme activity and that the Ser333Ala mutation decreased the activity significantly. The remaining mutants cause a partial loss of catalytic activity. All of the mutant enzymes, except Asn390Ala, were apparently correctly assembled and stable in the membrane of the R. capsulatus.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.4
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• pp.1-9
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• 2003

Many CDMA systems provide pilot channels in order to help channel estimation process. Especially in wideband CDMA systems, the number of receive diversity paths can be large due to small chip duration and high multi-path resolution capability. Hence, the received signal power of each path is small for a given total SNR (signal-to-noise ratio) and the pilot power of each path may not be sufficiently large for accurate channel estimation. When the pilot power is small, one can use decision-directed channel estimation to utilize more energy of the received data. However, the decision errors can deteriorate the quality of decision-directed channel estimation. This paper proposes a novel channel estimation method that optimally utilizes receiver decisions as well as pilot symbols with the help of estimated SER (symbol error rate) and SNR. The proposed method computes two channel estimates using the pilot and the data channel filters and optimally combines them. The simulation results show that the proposed method is robust and outperforms the conventional pilot-symbol-aided channel estimation method.

• Journal of Electrochemical Science and Technology
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• v.10 no.3
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• pp.284-293
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• 2019

Herein, we report an electrode surface with a hierarchical assembly of wild-type M13 virus nanofibers (M13) to nucleate the AuPt alloy nanostructures by electrodeposition. M13 was pulled on the electrode surface to produce a virus film, and then a layer of sol-gel matrix (SSG) was wrapped over the surface to protect the film, thereby a bio-template was constructed. Blending of metal binding domains of M13 and amine groups of the SSG of the bio-template were effectively nucleate and directed the growth of nanostructures (NSs) such as Au, Pt and AuPt alloy onto the modified electrode surface by electrodeposition. An electrocatalytic activity of the modified electrode toward methanol oxidation in alkaline medium was investigated and found an enhanced mass activity ($534mA/mg_{Pt}$) relative to its controlled experiments. This bio-templated growth of NSs with precise composition could expedite the intention of new alloy materials with tuneable properties and will have efficacy in green energy, catalytic, and energy storage applications.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.9-9
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• 2011

The transfer of nano-science accomplishments into technology is severely hindered by a lack of understanding of barriers to nanoscale manufacturing. The NSF Center for High-rate Nanomanufacturing (CHN) is developing tools and processes to conduct fast massive directed assembly of nanoscale elements by controlling the forces required to assemble, detach, and transfer nanoelements at high rates and over large areas. The center has developed templates with nanofeatures to direct the assembly of carbon nanotubes and nanoparticles (down to 10 nm) into nanoscale trenches in a short time (in seconds) and over a large area (measured in inches). The center has demonstrated that nanotemplates can be used to pattern conducting polymers and that the patterned polymer can be transferred onto a second polymer substrate. Recently, a fast and highly scalable process for fabricating interconnects from CMOS and other types of interconnects has been developed using metallic nanoparticles. The particles are precisely assembled into the vias from the suspension and then fused in a room temperature process creating nanoscale interconnect. The center has many applications where the technology has been demonstrated. For example, the nonvolatile memory switches using (SWNTs) or molecules assembled on a wafer level. A new biosensor chip (0.02 $mm^2$) capable of detecting multiple biomarkers simultaneously and can be in vitro and in vivo with a detection limit that's 200 times lower than current technology. The center has developed the fundamental science and engineering platform necessary to manufacture a wide array of applications ranging from electronics, energy, and materials to biotechnology.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.11
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• pp.2441-2446
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• 2009

Wireless Sensor Network collects a data from the specific area and the control is composed of small sensor nodes. Like this sensors to after that is established at the beginning are operated with the battery, the operational duration until several years must be continued from several months and will be able to apply the resources which is restricted in efficiently there must be. In this paper RHC (rounting history cache) applies in Directed Diffusion which apply a data central concept a reliability and an efficiency in data transfer course set. RHC algorithms which proposes each sensor node updated RHC of oneself with periodic and because storing the optimization course the course and, every event occurrence hour they reset the energy is wasted the fact that a reliability with minimization of duplication message improved.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.1018-1021
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• 2009

Wireless Sensor Network collects a data from the specific area and the control is composed of small sensor nodes. Like this sensors to after that is established at the beginning are operated with the battery, the operational duration until several years must be continued from several months and will be able to apply the resources which is restricted in efficiently there must be. In this paper RHC (rounting history cache) applies in Directed Diffusion which apply a data central concept a reliability and an efficiency in data transfer course set. RHC algorithms which proposes each sensor node updated RHC of oneself with periodic and because storing the optimization course the course and, every event occurrence hour they reset the energy is wasted the fact that a reliability with minimization of duplication message improved.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.12
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• pp.113-122
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• 2021

Complicated residual stress distributions occur in the vicinity of a deposited region via directed energy deposition (DED) process owing to the rapid heating and cooling cycle of the deposited region and the substrate. The residual stress can cause defects and premature failure in the vicinity of the deposited region. Several heat treatment technologies have been extensively researched and applied on the part deposited by the DED process to relieve the residual stress. The aim of this study was to investigate the residual stress characteristics of a specimen fabricated by DED and a quenching process using thermomechanical analyses. A coupled thermomechanical analysis technique was adopted to predict the residual stress distribution in the vicinity of the deposited region subsequent to the quenching step. The results of the finite element (FE) analyses for the deposition and the cooling measures show that the residual stress in the vicinity of the deposited region significantly increases after the completion of the elastic recovery. The results of the FE analyses for the heating and quenching stages further indicate that the residual stress in the vicinity of the deposited region remarkably increases at the initial stage of quenching. In addition, it is observed that the residual stress for quenching is lesser than that after the elastic recovery, irrespective of the deposited material.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.6
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• pp.41-49
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• 2022

The Internet Engineering Task Force (IETF) has standardized RPL (IPv6 Routing Protocol for Low-power Lossy Network) as a routing protocol for Low Power and Lossy Networks (LLNs), a low power loss network environment. RPL creates a route through an Objective Function (OF) suitable for the service required by LLNs and builds a Destination Oriented Directed Acyclic Graph (DODAG). Existing studies check the residual energy of each node and select a parent with the highest residual energy to build a DODAG, but the energy exhaustion of the parent can not avoid the network disconnection of the children nodes. Therefore, this paper proposes EC-RPL (Enhanced Connectivity-RPL), in which ta node leaves DODAG in advance when the remaining energy of the node falls below the specified energy threshold. The proposed protocol is implemented in Contiki, an open-source IoT operating system, and its performance is evaluated in Cooja simulator, and the number of control messages is compared using Foren6. Experimental results show that EC-RPL has 6.9% lower latency and 5.8% fewer control messages than the existing RPL, and the packet delivery rate is 1.7% higher.