• Journal of Microbiology and Biotechnology
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• 제23권12호
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• pp.1765-1773
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• 2013

The cathode reaction is one of the most seriously limiting factors in a microbial fuel cell (MFC). The critical dissolved oxygen (DO) concentration of a platinum-loaded graphite electrode was reported as 2.2 mg/l, about 10-fold higher than an aerobic bacterium. A series of MFCs were run with the cathode compartment inoculated with activated sludge (biotic) or not (abiotic) on platinum-loaded or bare graphite electrodes. At the beginning of the operation, the current values from MFCs with a biocathode and abiotic cathode were $2.3{\pm}0.1$ and $2.6{\pm}0.2mA$, respectively, at the air-saturated water supply in the cathode. The current from MFCs with an abiotic cathode did not change, but that of MFCs with a biotic cathode increased to 3.0 mA after 8 weeks. The coulomb efficiency was 59.6% in the MFCs with a biotic cathode, much higher than the value of 15.6% of the abiotic cathode. When the DO supply was reduced, the current from MFCs with an abiotic cathode decreased more sharply than in those with a biotic cathode. When the respiratory inhibitor azide was added to the catholyte, the current decreased in MFCs with a biotic cathode but did not change in MFCs with an abiotic cathode. The power density was higher in MFCs with a biotic cathode ($430W/m^3$ cathode compartment) than the abiotic cathode MFC ($257W/m^3$ cathode compartment). Electron microscopic observation revealed nanowire structures in biofilms that developed on both the anode and on the biocathode. These results show that an electron-consuming bacterial consortium can be used as a cathode catalyst to improve the cathode reaction.

• 한국전자파학회논문지
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• 제27권1호
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• pp.84-87
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• 2016

본 논문에서는 자기공명 방식의 무선전력전송 시스템용 100 W급 수신기를 설계, 제작하였다. 제안된 수신기는 1.8 MHz 대역, 100 W급 full-bridge 다이오드 정류기와 정전류 충전기로 구성되어 있다. 특히 정류기에는 30 V 이상의 과전압으로부터 수신기를 보호하는 과전압 보호회로와 수신기에 입력되는 여분 전력을 자동으로 소모하여 수신기의 임력임피던스를 부하변동에 관계없이 일정하게 유지시키는 능동 더미 부하가 내장되어 있다. 정전류 충전기는 최대 1 A의 충전 전류로 배터리를 충전할 수 있도록 설계, 제작되었으며, 충전전류를 제어할 수 있도록 구성되었다. 구성된 수신기를 이용하여 자기공명방식 무선충전 시스템을 구성하였다. 시스템은 130 W 송신기, 1.8 MHz 대역 송수신 공진기, 그리고 제안된 수신기로 구성되어 있으며, 자기공명방식으로 48 V 리튬-이온 배터리를 충전하도록 설계되었다. 시스템 측정 결과, 30 cm의 전송거리에서 약 54 %의 시스템 효율을 나타내었다.

• ETRI Journal
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• 제30권1호
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• pp.113-128
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• 2008

Turbo codes are extensively used in current communications standards and have a promising outlook for future generations. The advantages of software defined radio, especially dynamic reconfiguration, make it very attractive in this multi-standard scenario. However, the complex and power consuming implementation of the maximum a posteriori (MAP) algorithm, employed by turbo decoders, sets hurdles to this goal. This work introduces an ASIP architecture for the MAP algorithm, based on a dual-clustered VLIW processor. It displays the good performance of application specific designs along with the versatility of processors, which makes it compliant with leading edge standards. The machine deals with multi-operand instructions in an innovative way, the fetching and assertion of data is serialized and the addressing is automatized and transparent for the programmer. The performance-area trade-off of the proposed architecture achieves a throughput of 8 cycles per symbol with very low power dissipation.

• Genomics & Informatics
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• 제18권2호
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• pp.18.1-18.5
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• 2020

Finding publications that propose alternative methods to animal experiments is an important but time-consuming task since researchers need to perform various queries to literature databases and screen many articles to assess two important aspects: the relevance of the article to the research question, and whether the article's proposed approach qualifies to being an alternative method. We are currently developing a Web application to support finding alternative methods to animal experiments. The current (under development) version of the application utilizes external tools and resources for document processing, and relies on the PubAnnotation ecosystem for annotation querying, annotation storage, dictionary-based tagging of cell lines, and annotation visualization. Currently, our two PubAnnotation repositories for discourse elements contain annotations for more than 110k PubMed documents. Further, we created an annotator for cell lines that contain more than 196k terms from Cellosaurus. Finally, we are experimenting with TextAE for annotation visualization and for user feedback.

• 대한교통학회지
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• 제12권1호
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• pp.85-95
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• 1994

While bicycles are an exhaust-free and low energy consuming mode of transport, the use of them is getting decreased. The aim of this research is to find out current levels of bicycle ownership and to estimate the ownerships of the bicycles by spatial structure and social factors in the metropolitan area. The parameters which affect on the characteristics of the bicycle ownership are classified into aggregate and disaggregate categories. The ownerships of the bicycles are estimated by the multiple regression analysis using urban characteristics data and the binary logit analysis using household characteristics data. The results of this study to population, car ownership, and number of male in the household, and negatively by the population density.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 F
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• pp.2139-2142
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• 1997

The most important thing in vector control scheme is the knowledge of accurate electrical motor parameters. These parameters can computed by conventional motor test, such as no-load and locked rotor tests. However, the values from these tests are different from actual motor parameters, and the adjustment process of the parameters is time consuming. This paper presents an auto-tuning method for vector control of induction motor. The tuning algorithm is based on the rotor flux behavior of the induction motor for stepwise torque current command. The transient terminal voltage caused by the undesirable variation of the rotor flux is used for tuning the slip gain $K_5$ defined as the inverse of the rotor time constant. The electrical parameters of induction motor can also calculated by this method. The presented method is evaluated through the computer simulations.

• 한국디지털건축인테리어학회논문집
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• 제12권1호
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• pp.109-118
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• 2012

The Purpose of this study is to develop a design process of free-formed super tall buildings with parametric design approach using BIM. Before BIM tools like Revit was developed, it is considered as very time consuming process and requires extensive efforts and costs for making free-formed super tall building modeling. Current trends of free-formed super tall building are for proofing city's economic strength and symbol. New digital tools have been developed and used for pursuing many design methods for building design. In this study, BIM based Parametric design approach is studied to seek for possibility of generating free-formed super tall building fast, easily, and accurately.

• 보건행정학회지
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• 제1권1호
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• pp.72-94
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• 1991

The number of disputes between physicians and patients caused by medical malpractice are showing a sharp increasing over the past several years. The disputes on medical malpractice may be resolved either in court or by direct negotiation between both sides concerned. There are no special acts relating to the civil or penal liability of the physicians in Korea. The medical disputes are decided merely through legal technicalities and without reference to actual medical practice. The current system which does not compensate injured patients adequately or equitably leads to taking a long time consuming for dispute resolution processes. The things make worsed, the problem is due to not being of insurance system or a proper funds for compensation. This research proposes a outline of new and comprehensive alternative for these problems and failure of conventional resolution of medical disputes. So far, we have learned lessons from the excperiencies of resolving medical malpractice disputes of Japan and the United States. The proposal first calls for an administrative arbitration and pretrial screening panels as a condition precedent to trial. The proposal also includes to facilitate with the funds for compensating the injured.

• Journal of Electrical Engineering and Technology
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• 제6권2호
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• pp.202-207
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• 2011

Numerous methodologies have been developed in an effort to reduce cogging torque. However, most of these methodologies have side effects that limit their applications. One approach is the optimization methodology that determines an optimized design variable within confined conditions. The response surface methodology (RSM) and the genetic algorithm (GA) are powerful instruments for such optimizations and are matters of common interest. However, they have some weaknesses. Generally, the RSM cannot accurately describe an object function, whereas the GA is time consuming. The current paper describes a novel GA and RSM hybrid algorithm that overcomes these limitations. The validity of the proposed algorithm was verified by three test functions. Its application was performed on a surface-mounted permanent magnet.

• 한국전산유체공학회지
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• 제21권4호
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• pp.85-89
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• 2016

Wing is the most important part of aircraft which produces lift. In general when aircraft takes off or lands, high lift is required and additional devices are adopted in front and aft-side of wing, which constitute so-called multi element airfoils. The objective of this research is to develop a specialized grid generation program to help engineers in reducing human labor and eliminating time-consuming process for mesh regeneration by deforming the initially-given grid system with efficient deforming method. This paper describes briefly about the mesh deformation methods, and provides some results to verify the quality of deformed mesh and eventually correctness of current approach.