• Journal of Magnetics
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• 제15권4호
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• pp.194-198
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• 2010

In our present work, we developed a GMI (giant magnetoimpedance) sensor system to detect magnetic fields in the milli gauss range based on the asymmetric magnetoimpedance (AGMI) effect in Co-based amorphous ribbon with self bias field produced by field-annealing in open air. The system comprises magnetoimpedance sensor probe, signal conditioning circuits, A/D converter, USB controller, notebook computer, and program for measurement and display. Sensor probe was constructed by wire-bonding the cobalt based amorphous ribbon with dimensions $10\;mm\;{\times}\;1\;mm\;{\times}\;20\;{\mu}m$ on a printed circuit board. Negative feedback was used to remove the hysteresis and temperature dependence and to increase the linearity of the system. Sensitivity of the milli gauss meter was 0.3 V/Oe and the magnetic field resolution and environmental noise level were less than 0.01 Oe and 2 mOe, respectively, in an unshielded room.

• 대한치과보철학회지
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• 제48권4호
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• pp.251-258
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• 2010

연구 목적: 이 연구의 목적은 표면처리방법이 지르코니아와 네 종류의 시멘트의 전단결합 강도에 미치는 영향을 평가하는 것이다. 연구 재료 및 방법: 총 120개의 디스크 모양의 산화 지르코늄 (3Y-TZP, Kyoritsu, Tokyo, Japan) 시편을 다음과 같이 표면처리 하였다: (1) $110\;{\mu}m$ 산화 알루미나 분사처리 (2) Silica coating ($Rocatec^{TM}$ 3M ESPE)를 이용한 표면처리 (3) 처리하지 않음. 각각의 표면 처리 후, 2종의 자가 접착형 시멘트 (RelyX Unicem, Maxcem)와 레진 강화 글라스 아이오노머 시멘트 (RelyX Luting), Bis-GMA 레진 시멘트 (Nexus3)를 시편에 부착하였으며 각 군은 UTM을 이용하여 전단결합강도를 측정하였다. 표면처리, 시멘트의 종류에 따른 결합강도의 차이를 살펴보기 위하여 일원변량분석 (One-way ANOVA)과 이원변량분석 (two-way ANOVA)을 이용하고 사후 분석으로 Tukey HSD test를 실시하였다. 결과: 로카텍 처리 후, RelyX Unicem을 부착한 군이 가장 높은 결합 강도를 보였으며 (P<.05) 알루미나 분사처리를 한 군과 로카텍 처리를 한 군은 아무런 처리를 하지 않은 군보다 유의하게 높은 결합 강도를 보였다 (P<.05). 또한 모든 표면상태에서 RelyX Luting은 다른 군에 비해 통계적으로 유의하게 가장 낮은 결합강도를 보였다 (P<.05). 결론: 본 연구의 결과에 따르면 RelyX Unicem은 지르코니아와 강한 결합력을 보였으며 로카텍 처리는 결합을 증진시키는데 효과적이었다.

• 동력기계공학회지
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• 제22권1호
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• pp.41-47
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• 2018

This paper analyzes the output characteristics of a self excited induction generator with isolated mode according to change of its speeds and loads for building a hybrid electric propulsion system in special purpose ships by using power take off. The induction generators are being considered as an alternative choice to the well-developed generators because of their lower unit cost, inherent ruggedness, operational and maintenance simplicity. However, the generator working by stand alone has a few problems that the reactive power is required to establish the air gap magnetic flux, and the induced voltage and magnetizing current fluctuate when the load is varied. In spite of its advantages, basic design data of the capacitor bank and behaviors of the output characteristics of the generator are not sufficient for the system. Based on the operating condition(speed range of main engine) of the target boat, a reduced experimental equipment system was constructed to analyze the output characteristics of the SEIG. And a suitable capacitor bank of a stand-alone generator and its output characteristics under various loads was investigated in detail through these experiments. According to the experimental result, it was confirmed that the capacitor bank should be $70{\mu}F{\sim}100{\mu}F$, and the proper SEIG induced voltage should be DC 80 V ~ 250 V in order to storage electrical energy into a battery.

• 영어영문학
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• 제56권2호
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• pp.383-408
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• 2010

This paper intends to suggest the positive, ecological vision of sustainability in Karen Hesse's Out of the Dust that Billie Jo Kelby recovers herself through her readjustment of interior consciousness and outer environment in her tragic situations caused by the Dust Bowl. In spite of her desires for happiness and affluence of home, she loses her mother and brother, and her musical talent as a pianist, and lies in self-abandonment. But she finally raises up herself with her courage and patience, reconciliating with the nature and ameliorating the community by taking care of the devastated landscapes. Hence it is appropriate to approach the loss-recovery process of nature and consciousness with ecological solutions, The Dust Bowl breaks down human mind and body, and eventually leads to the situations of despairs and death. Hesse proposes the primary solution that humans should reconstruct their interior consciousness and participate in recovering the nature because humans are inevitably linked with nature. In this novel, the nature takes a dynamic and active role as a catalyst, reconciling the self with other humans and settling with the conflicting situations in history and culture. This verse novel as an active, self-ordering, and corrective process gives the more intense ecological message. As Hesse defines the setting of Dirty Thirties as a channel of energy, she creates the utmost effects of ecological process that human and environment are part of a total situation, representing the transactional formulation, each conditioned by conditioning to the other. Therefore Billie Jo takes her part as an interpreter and actualizes herself, understanding the nature with metaphor and symbol. Eventually Billie Jo realizes that she should rebuild her environment not out of the dust but in the dust, accepting the reality of Dust Bowl.

• Journal of Biosystems Engineering
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• 제11권1호
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• pp.24-30
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• 1986

In order to collect the engine performance data accurately, rapidly and reliabily, the microcomputer-based engine performance test system was developed and tested. The system measures engine shaft torque and speed, fuel consumption, exhaust gas temperature, engine shaft power and fuel consumption ratio. The system consisted of 32 channels 8 bit A/D converter, time clock, dynamic strain amplifier and signal conditioning circuits to amplify and filter the electrical signal from transducers. Most of transducers were devised for low cost, easy setting and self-manufacturing. The system has been installed on a small kerosene engine (DAEDONG NA50B).

• 조명전기설비학회논문지
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• 제26권8호
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• pp.42-49
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• 2012

Grid-connected photovoltaic generator system requires high performance PCS(Power Conditioning System) according to the standard of 'Distributed Generation Grid-Connected Technology Standards'. This paper presents the MPPT control method which improves output efficiency through fast tracking to the maximum power point of PV and a reduced self-excited vibration. Secondly, in this paper DVR function was applied to PCS to compensate the voltage sag frequently happening for a power system. The proposed PCS control is analyzed and compared to conventional PCS operating characteristic, the various insolation and loads, and voltage sag condition through PSIM tool. It proves the utility.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.1395-1404
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• 1993

Application of water-saving self-feeders can reduce water consumption of pigs by more than 50% . so the feeding-watering system one of the most important way of the reduction of the slurry. Bioactive deep litter housing can eliminate slurry. Matured urine, faeces and litter can use for the purposes of soil conditioning and fertilizing . Water-saving slurry handling technology can halve manure dilution so it can double the nutrient content of the slurry. By using of straw bale biofilter for reducing emissions of pig houses makes fattening of pigs possible close to populated area. Developed rate control system for slurry application make avoiding over-fertilization possible , can fulfill better the demand of nutrient of plants. By means of computer aided manure utilization system area distribution of soil characteristics can determinate . The system is suitable for planning the utilization of manure and slurry in environment -friendly way.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.78-81
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• 2003

Polishing Processes are widely used in the glass, optical, die and semiconductor industry and are conventionally carried out using abrasive slurry and a polishing pad. But abrasive slurry process has a weak point that is high cost of handling of used slurry and hard controllability of slurry. Recently, some researches have attempted to solve these problems and one method is the development of a fixed abrasive pad. FAP has a couple of advantages including clean environment, lower CoC, easy controllability and higher form accuracy. But FAP also has a weak point that is need of dressing because of glazing and loading. The paper introduces the basic concept and fabrication technique of FAP using hydrophilic polymers with swelling characteristics in water and explains the self-conditioning phenomenon. Experimental results demonstrate to achieve nano surface roughness of soda lime glass for optical application

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2004년도 하계학술발표 논문집
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• pp.56-56
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• 2004

• 한국정보처리학회논문지
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• 제7권11호
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• pp.3356-3371
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• 2000

본 논문에서는 분산시스템 환경에서 n개의 노드가 결함일 경우, 결함을 허용해 주고, 시스템의 안정성을 유지하면서, 결함 노드의 부하를 정상 노드로 조절하기 위하여 부하 조절 알고리즘 전송정책, 위치 정책, 선정 정책을 제안하였다. 이러한 메카니즘은 부하 상태의 정보를 효과적으로 획득하고, 응답 시간을 줄이기 위하여 자기 학습 경험을 기반으로 하는 최적의 알고리즘을 선정할 수 있었다. 결과적으로 이를 기반으로 유사한 상황에서도 최적의 알고리즘을 선정할 수 있음을 알 수 있었다. 각 기법들의 효율성에 영향을 미칠 수 있는 매개변수를 적용하여 성능평가를 하였다. 성능평가 결과 작업 도착 율, 서비스 율, 노드 결합 율은 서로간에 영향을 주지 못하고, 다만 결함 수리 율과 특히 부하의 이주에 대한 통신 지연 시간의 크기에 민감한 영향을 주었다.