• The KIPS Transactions:PartC
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• v.14C no.5
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• pp.395-402
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• 2007

Wireless sensor networks have many sensor nodes which response sudden events in a sensor fields. Some efficient routing protocol is required in a sensor networks with mobile sink node. A data-path template is offered for the data announcement and data request from source node and sink node respectively. Sensed data are transferred from source node to sink node using short-distance calculation. Typical protocols for the wireless networks with mobile sink are TTDD(Two-Tier Data Dissemination) and CBPER(Cluster-Based Power-Efficient Routing). The porposed SPDR(Short-Path Data Routing) protocol in this paper shows more improved energy efficiencies from the result of simulations than the typical protocols.

• Journal of Power Electronics
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• v.11 no.3
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• pp.264-270
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• 2011

In this paper a novel passive snubber is proposed, which can suppress the voltage spike across the bridge leg of the isolated full-bridge boost topology. The snubber is composed of capacitors, inductors and diodes. Two capacitors connected in series are used to absorb the voltage spike and the energy of each capacitor can be transferred to the load during one switching cycle by the resonance of the inductors and capacitors. The operational principle of the passive snubber is analyzed in detail based on a three-phase power factor correction (PFC) converter, and the design considerations of both the converter and the snubber are given. Finally, a 3kW laboratory-made prototype is built. The experimental results verify the theoretical analysis and evaluations. They also prove the validity and feasibility of the proposed methods.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.401-402
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• 2015

In this paper a direct cell-to-cell charge balancing circuit which can transfer the charge from any cell to any cell in the battery string is introduced. In the proposed topology the energy in the high voltage cell is transferred to the low voltage cell through the simple operation of a dc-dc converter to get fast equalization. Furthermore, the charge equalization can be performed regardless of the battery module operation whether it is being charged, discharged or relaxed. The monitoring circuit composed of a DSP and a battery monitoring IC is designed to monitor the cell voltage and protect the battery. In order to demonstrate the advantages of the proposed topology, a prototype circuit was designed and applied to 12 Lithium-Ion battery module. It has been verified with the experiments that the charge equalization time of the proposed method was shortest compared with those of other methods.

• The Journal of Information Technology
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• v.3 no.3
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• pp.27-37
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• 2000

Although an insurance criterion for reliance is unified, the difference in evaluation mechanism in every country is already ambiguity. In other words, the aspect of objectivity would be a little because it is true that the vulnerability evaluation include evaluator, scenario and tools (TSVES) applying in test, depth and scope of evaluation. But evaluation results can be difference in accordance with each evaluation elements. By using TSVES to evaluating network security vulnerability, first, we expected the evaluation results is impartiality, objectivity, repeatability, reproducibility, appropriateness and soundness of results. Second, it could be transferred manual ways into automation ways, and then expected easiness and safety of extension and modification in a quality of products as well as a dramatical reduction of waste of time and energy.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.368-368
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• 2010

Monolayers of graphite can be grown by fine controlled surface graphitization on the surfaces of various metallic and semiconducting materials. Epitaxial graphene grown on polished silicon carbide crystal surfaces has drawn much attention due to well known vacuum annealing procedures from surface analysis methods, especially scanning tunneling microscopy(STM) and scanning tunneling spectroscopy(STS). In this study, we have grown single layer and few layer graphene on silicon terminated 6H-SiC(0001) crystals. The growth of graphene layers were observed by low energy electron diffraction(LEED) patterns. Scanning tunneling microscopy and spectroscopy measurements were performed to illustrate the electronic structure which may display some clue on the influence of the underlying structure. Spatially resolved STS results acquired at the edges of epitaxial graphene show in detail the electron density of states, which is compared to theoretical calculations. STM measurements were also done on graphene films grown by chemical vapor deposition(CVD) and transferred onto a SiC(0001) crystal. These observations may provide a hint for the understanding of carrier scattering at the edges.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.10
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• pp.931-939
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• 2010

A dash panel plays an important role to protect noise as well as heat. Meanwhile, it is also the most important path that transfers energy to the interior cavity, so that some of noises are transferred via air and its structural vibration becomes a major issue. From the viewpoint of NVH performance, simplified structures analogues to the dash wall are dealt with. Stiffeners, damping sheets and sound packages attached to a flat panel are taken into account as design variables. Structural radiation characteristics(thus, structure borne) such as radiation efficiency and radiation power are mainly discussed. For the case when an excitation is applied on a frame that surrounds the panel, it is shown that the radiation efficiency increases by attaching a stiffener to the panel, which is similarly found from the case when a panel is directly excited. It seems more effective to attach damping sheets along the boundary area of the panel rather than its middle area. The radiation efficiency of sound packages may make a dominant contribution to transmission loss as well as sound radiation. Experimental work was carried out to verify the results based on the simulation study.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2001.11a
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• pp.118-125
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• 2001

Most of the laws and standards relevant to technology in Korea bear a resemblance to those in Japan. Electricity was not introduced to Korea until Lighting ceremony in Kyong-Bok palace observed in 1887. Since Korea was annexed to Japan in 1910 and our public works were under Japan control we have applied Japanese laws and regulations made by Chosun government-general. Independently from Japan the power electricity accepted power plants of USA, codes of NESC, ASME / ANSI, NEMA. Our generation and distribution system takes American style while our consumer side takes Japanese style. As global trade system was transferred GATT into WTO, the harmonization of technological standards, certification construction testing in the trend of world. This paper is based on WTO / TBT agreement coming in effect after 12th, April, 1979. For Korea the distribution system has a strong resemblance to American system so that unconvertible because IEC 60364 originated from Europe while NEC originated from USA. This papers deals with the fundamental elements of electrical safety system with comparing IEC 60364 with NEC. This paper considers how engineers should apply NFPA 70(NEC) and IEC based on the comparison of NEC to IEC in relation to electrical installations.

• The Journal of Asian Finance, Economics and Business
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• v.6 no.1
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• pp.261-271
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• 2019

The study aims to investigate corporate social responsibility (CSR) best practices of the world automotive industry - Peugeot, BMW, Ford, Hyundai and Toyota among others - and recommend that they plan their business strategies and managerial responses accordingly. Based on the comparative research and case studies, this research finds that all five automobile manufacturers have taken very similar measures and actions in order to establish and maintain a high level of CSR practices. Sustainability was a core value in all five companies and served as a guiding principle in every aspect and approach of their business. This study finds that all five companies have CSR strategies in place to increase energy efficiency as well as reduce the usage and wastage of water in their production and plants. This research also finds that all companies monitor their suppliers and their own production process to ensure that they maintain their CSR standards. More impressively, this sustainable management practice is transferred along the companies' supply chain through education and training. Their suppliers and business partners are closely monitored to make sure that their high CSR standards are respected and followed. However, we find that there also are some differences in terms of their CSR deliveries and activities.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.7-8
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• 2015

In this paper a cell-to-cell fast charge balancing circuit for the Lithium-Ion battery module is proposed. In the proposed topology the energy in a high voltage cell is transferred directly to a low voltage cell through the operation of the dc-dc converter. Furthermore, the charge balancing can be performed regardless of the battery operation whether it is being charged, discharged or relaxed. The monitoring circuit composed of a DSP and a battery monitoring IC is designed to monitor the cell voltage and detect the inferior cell thereby protecting the battery module from failure. In order to demonstrate the performance of the proposed topology, a prototype circuit was designed and applied to 12 Lithium-Ion battery module. It has been verified with the experiments that the charge equalization time of the proposed method was shorter compared with those of other methods.

• Journal of the Korean Magnetic Resonance Society
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• v.22 no.4
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• pp.139-143
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• 2018

Short antimicrobial peptide, A4W, have been studied by molecular dynamics (MD) simulation in an explicit dodecylphosphocholine (DPC) micelle. Peptide was aligned with DPC micelle and transferred new peptide-micelle coordinates within the same solvent box using specific micelle topology parameters. After initial energy minimization and equilibration, the conformation and orientation of the peptide were analyzed from trajectories obtained from the RMD (restrained molecular dynamics) or the subsequent free MD. Also, the information of solvation in the backbone and the side chain of the peptide, hydrogen bonding, and the properties of the dynamics were obtained. The results showed that the backbone residues of peptide are either solvated using water or in other case, they relate to hydrogen bonding. These properties could be a critical factor against the insertion mode of interaction. Most of the peptide-micelle interactions come from the hydrophobic interaction between the side chains of peptide and the structural interior of micelle system. The interaction of peptide-micelle, electrostatic potential and hydrogen bonding, between the terminal residues of peptide and the headgroups in micelle were observed. These interactions could be effect on the structure and flexibility of the peptide terminus.