• 한국수소및신에너지학회논문집
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• 제20권6호
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• pp.492-498
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• 2009

Six sigma methode was applied for optimization of flow field design of a proton exchange membrane fuel cell (PEMFC). The optimization between number of channel and channel/rib width was suggested in this paper with six sigma method. With the help of six sigma design of experiment (DOE) the number of experiments may be reduced dramatically. The fuel cell channel design optimization with results of these experiments with a 100 $cm^2$ serpentine flow field indicates a optimization data for a given constant operating conditions.

• 한국초전도ㆍ저온공학회논문지
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• 제19권3호
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• pp.1-7
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• 2017

It is required to reduce the cost of superconducting cable to realize a superconducting DC power network that covers a wide area in order to utilize renewable energy. In this paper a new concept of innovative cable is introduced that can enhance the current-carrying capacity even though the same superconducting tape is used. Such a cable can be realized by designing an optimal winding structure in such a way that the angle between the tape and magnetic field becomes small. This idea was confirmed by preliminary experiments for a single layer model cable made of Bi-2223 tapes and REBCO coated conductors. Experiments of three and four layer cables of practical sizes were also done and it was found that the current-carrying capacity increased as theoretically predicted. If the critical current properties of commercial superconducting tapes are further improved in a parallel magnetic field, the enhancement will become pronounced and this technology will surely contribute to realization of superconducting DC power network.

• 한국미생물·생명공학회지
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• 제46권4호
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• pp.395-402
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• 2018

The efficacy of formulated Trichoderma harzianum-based Tricho-compost, seed treatment with Tricho-inocula, and chemical fungicide Provax 200 WP against foot and root rot diseases of wheat caused by Sclerotium rolfsii was tested in the pot house and in the research field of Plant Pathology Division, Bangladesh Agricultural Research Institute, Gazipur, Bangladesh. Tricho-compost was prepared with a mixed substrate of cow dung, rice bran, and poultry refuse colonized by T. harzianum. Seedling mortality of wheat was significantly reduced by the Tricho-compost, Tricho-inocula, and Provax 200 WP both in the pot house as well as in the field experiments. The yield of wheat was sharply increased over the control due to the T. harzianum formulations and Provax 200 WP. Among the treatments, soil application of Tricho-compost was more efficient in reducing seedling mortality and accelerating plant growth with an increased yield of wheat with S. rolfsii-inoculated pot cultures and field experiments.

• 센서학회지
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• 제32권6호
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• pp.487-495
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• 2023

Over the past few decades, considerable research has been conducted on field-effect transistor (FET) biosensors; however, other than electrochemical sensors for pH, they have not reached the commercialization stage and still remain at the basic research level. Although several reports have been published on experiments with real biological samples, no reports exist of developments that have reached commercialization or finalized approval for use. In this paper, we explain the reason for the experiments of FET biosensors to induce spurious signals in an experimental setup and explain the existence of misunderstandings regarding the operating principle of FET biosensors owing to the spurious signals. Based on the thoughtful review of the results of previously published papers, we show that the electrochemical read-out principle of FET biosensors requires our intensive understanding of the interfacial potential between the solution and the sensor electrode for further progress in the FET biosensor research.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.1473-1478
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• 2010

For the cassion type of breakwater under the condition of large wave loads, stability about lateral movement of breakwater was investigated by performing centrifuge model experiments. Prototype of breakwater was modelled by scaling down to centrifuge model and the soft ground reinforced with grouting was also reconstructed in the centrifuge model experiments. Sandy ground beneath breakwater was prepared with a soil sampled in field so that identical value of internal friction angle could be obtained. Centrifuge model experiments were carried out to reconstruct the construction sequence in field. Lateral static wave load was applied to the model caisson after the final stage of construction sequence was rebuilt and the measured lateral movement of caisson was compared with allowable value by the code to assess the stability about lateral movement of the breakwater.

• ETRI Journal
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• 제29권2호
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• pp.135-142
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• 2007

The small anechoic chambers built by many small-/medium-sized companies and universities present difficulties in testing electrically large antennas because the chamber size cannot satisfy the far-field criterion of large antennas. In this paper, a method for Fresnel-region measurement on a cylindrical surface with variation of the measurement height is proposed and verified by both calculations and experiments. We implement the proposed method using a direct far-field measurement system by adding a few supporting structures. The results show good accuracy.

• Journal of Power Electronics
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• 제10권3호
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• pp.300-305
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• 2010

This paper presents a two Hall sensor method for rotor angle detection in permanent magnet synchronous motors (PMSM). To minimize the implementation complexity, the system is designed to measure the edge field of permanent magnet pieces. However, there are nonlinearities in the measured values of the edge field. In this work, an angle correction algorithm is proposed, and the improvements in accuracy are verified through experiments. Finally, a field orientation controller is constructed with the proposed angle detection algorithm.

• Journal of the Korean Data and Information Science Society
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• 제9권1호
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• pp.57-62
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• 1998

The minimum number of samples for the measurement of plant characteristics of major crops were calculated from the data obtained from the field experiments on rice, barley, wheat, soybean and sweet potato conducted by Kyungpuk Rural Development Administration.

• 센서학회지
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• 제4권2호
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• pp.14-21
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• 1995

본 논문은 전력설비와 뇌방전에 의하여 발생하는 시변자장을 측정할 수 있는 능동성 자장측정계에 대하여 기술하였다. 자장측정계는 루우프형 센서, 차동증폭기로 동작되는 능동성 적분기로 이루어졌다. 시변자장측정계와 교정장치의 이론적 원리 및 설계방법에 대하여 제시하였으며, 교정실험으로부터 주파수대역 $270\;Hz\;{\sim}\;2.3\;MHz$, 응답감도 128 $mV/{\mu}T$를 얻었고, 교정실험계에서 자장센서범위의 자계의 세기는 ${\pm}3\;%$이내로 균일하였다. 적용실험으로는 대전류 발생장치에 의하여 모의 뇌임펄스전류와 진동성 임펄스전류를 발생시켜서 인가전류와 검출자장의 파형을 비교하였으며, 이의 결과는 거의 일치하였고, 편차는 0.5 %이내이었다.

• 한국전자파학회논문지
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• 제14권8호
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• pp.871-877
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• 2003

본 논문에서는 생체 실험용 극저주파 자기장 발생장치를 설계하였다. 생체실험 대상 동물이 유동적이지 않고 고정될 경우, 인가 자기장의 방향성에 대한 영향이 있을 수 있다. 이 방향성 영향을 줄이기 위해 2 축에 4개씩, 총 8개의 코일을 사용하여 2축 4중 Helmholtz 코일 구조의 장치를 설계하였다. 정육면체 구조의 자기장 발생 장치를 원통형으로 근사화시킨 수식을 유도하여, 원하는 특정 자기장을 위한 권선수 및 전류치를 계산하였으며, 각 코일의 최적 위치 및 최적 권선비는 수치계산을 통하여 구하였다. 이렇게 얻어진 수치들을 MATLAB 으로 제작한 계산 프로그램에 적용하여, 발생장치 주변에서의 자기장 분포를 계산 해보았으며, 공간에 따른 자기장 세기의 균일도를 평가하여 균일 자기장 분포영역 또는 생체 실험가능 영역을 도출하였다. 잘 설계된 장치의 해석 결과, 임의 기준 자기장에 대해 약 95 %의 균일도를 만족시키는 공간은 정육면체 구조에서 축길이의 60 % 이상이 됨을 확인하였다.