• Journal of information and communication convergence engineering
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• 제13권1호
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• pp.36-41
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• 2015

With the rapidly increasing and widespread use of electronic and controlling equipment, the control of the electromagnetic (EM) wave environment becomes an important social issue. To solve the electromagnetic compatibility (EMC, both electromagnetic interface and electromagnetic susceptibility) problems, in this paper, we introduce the countermeasure techniques focused on EM wave absorbers for EMC problems in our laboratory at the Korea Maritime and Ocean University. The current technologies related to EM wave absorbers to solve EMC problems will first be described. The prospects of and a design for EM wave absorbers including a smart absorber with a heat radiating function will then be suggested.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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• pp.155-161
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• 2000

In this paper, we studied the relation between heat-treatment temperature of ferrite and electromagnetic wave absorbing properties of ferrite-rubber composite. The heat-treatment temperatures of ferrite are 1200 and $1300^{\circ}C$, 2 hr. As s result. it has been shown that the optimum heat-treatment temperature of ferrite for electromagnetic wave absorber are related to the chemical composition. And, we can control electromagnetic wave absorbing properties of ferrite-rubber composite by the control of heat-treatment temperature of ferrite.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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• pp.162-166
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• 2000

In this paper, we studied the relation between using amount of Ferrite and electromagnetic wave absorbing properties of ferrite-rubber composite. The variation of using amount of Ferrite have been 52 wt.% ~ 62 wt.%. As s result, it has been shown that the electromagnetic wave absorbing properties of ferrite-rubber composite are related to the using amount of Ferrite in composite. And, we can control electromagnetic wave absorbing properties of ferrite-rubber composite by the control of using amount of Ferrite.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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• pp.149-154
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• 2000

In this paper, we studied the relation between addition of carbon and electromagnetic wave absorbing properties of ferrite-rubber composite. The ratio of carbon was 7 wt%. As s result, it has been shown that the electromagnetic wave absorbing properties of ferrite-rubber composite are changed by the addition of carbon in composite. And, we can control electromagnetic wave absorbing properties of ferrite-rubber composite by the using of carbon.

• Journal of electromagnetic engineering and science
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• 제16권4호
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• pp.225-228
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• 2016

KRISS-V, a V-band millimeter-wave source module for a primary RF power standard and calibration system developed by the Korea Research Institute of Standards and Science is here presented. The output power of KRISS-V is several times higher than that of commercial amplifier/multiplier chains and is highly stable (the standard deviations of output power are less than 0.01% in the worst case). The spectral purity of KRISS-V is high enough to consider it a single-tone signal generator. We also added programmable attenuation capability to KRISS-V for remote power control. Moreover, the in-house source module is cost-effective and adaptable to various measurement schemes. The structure of the model as well as detailed component information are introduced so that it can be reproduced.

• 대한치과교정학회지
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• 제24권4호
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• pp.897-916
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• 1994

The biologic potential, which is different from the piezoelectric signals, relates tooth movement at least in part to changes in bone metaboliosm in bioelectric theory. The purpose of this experiment was to determine wheather the application of half sine-wave pulsed electromagnetic fields (HSPEMF) could increase both the rate and amount of orthodontic tooth movement. Forty-three male Hartley guinea pigs, weighting approximately 255g, were utilized in this study. The animals were 35 days old at the start of the study. Laterally directed orthodontic force was applied to the maxillary central incisors of 40 Hartley guinea pigs (20 experimental, 20 control). According to the amount of orthodontic force (6g, 12g), they were divided into two sub-groups (10 experimental I, 10 experimental II, 10 control I, 10 control II). During the experimental period, experimental animals were placed in plastic animal holders with their heads positioned in an area of uniform electromagnetic field. Control animals were placed in similar plastic holders that did not carry the electric apparatus. The results were as follows : 1. The application of a HSPEMF to the experimental groups significantly increase the final amount of orthodontic tooth movement observed over a 10-day experimental period. 2. The application of a HSPEMF to the experimental groups significantly increase the velocity of orthodontic tooth movement observed over a 10-day experimental period. 3. There was no significant difference in the final amount of orthodontic tooth movement at the fourth day to the eighth day, but there was significant difference in the final amount of orthodontic tooth movement at the nineth, tenth day during a 10-day experimental period. 4. After 10 days of HSPEMF exposure & orthodontic force, the experimental groups demonstrated more osteodasts in the pressure side than control groups.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2000년도 춘계종합학술대회
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• pp.109-114
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• 2000

본 연구에서는 전파흡수체용 ferrite-Rubber Composite에서 Ferrite의 열처리 온도와 Composite의 전파흡수특성과의 상관관계에 관하여 알아보았다. 이때 Ferrite는 스피넬 구조의 형성과 결정입의 비교적 큰 성장을 위하여 1100, 1200, 1300 $^{\circ}C$에서 각각 2시간 열처리 처리하였다. 열처리 온도를 달리하여 제조한 Ferrite-Rubber Composite는 A가 Mn인 경우에는 열처리 온도가 높을수록 반사감쇠량이 작아지는 경향을 보였다. 그러나 A가 Cu와 Mg인 경우 열처리 은도가 높을수록 페라이트의 반사감쇠량이 커지는 경향을 보였다. 이로부터 전파흡수체용 Ferrite는 화학조성에 따라서 적정 열처리 온도가 존재함을 알 수 있었다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2000년도 춘계종합학술대회
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• pp.160-164
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• 2000

본 연구에서는 전파흡수체용 Ferrite-Rubber Composite에서 Ferrite의 함량과 Composite의 전파흡수특성과의 상관관계에 관하여 알아보았다. 이때 Ferrite는 스피넬 구조의 형성과 결정입의 비교적 큰 성장을 위하여 $1200^{\circ}C$에서 2시간 열처리하여 제조한 시료를 사용하였다. $1200^{\circ}C$에서 열처리된 Ferrite를 사용한 Composite는 Ferrite 함량이 52 wt.%에서 57 wt.%로 증가하면 정합주파수는 변화는 없으며, 반사감쇠량이 증대되며, 62 wt.%인 경우, 정합주파수의 이동현상이 발생됨을 알 수 있었다. 이로부터 전파흡수체용 Ferrite-Rubber Composite에서 Ferrite 함량을 제어하므로써 Composite의 전파흡수특성을 제어하는 것이 가능하다는 것을 알 수 있었다.

• 한국항해항만학회지
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• 제27권1호
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• pp.71-74
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• 2003

Sheet형 전파흡수체를 제조하고 그들의 전자파 흡수 특성을 조사하였다. 제조된 ferrite 흡수체의 흡수특성은 2.4~3.2GHz의 주파수범위에서 입자크기의 감소에 따라 개선되었다.

• 한국작물학회지
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• 제42권2호
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• pp.141-145
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• 1997

원적외선 복사 물질인 세라믹 분말을 벼 기계이앙상토에 혼합하였을 때 벼 유묘의 생장에 미치는 효과를 분석하고, 세라믹 분말의 적정혼합비를 구명하기 위하여 실험을 실시하였다. 공시 품종은 화성벼로 하였고, 세라믹 분말은 $Al_2$O$_3$계를 사용하였다. 시험한 결과를 요약하면 다음과 같다. 1. 시험에 사용한 세라믹 분말의 복사파장 범위는 6~11$mu extrm{m}$이었다. 2. 세라믹 분말의 혼합처리는 무처리에 비하여 초장이 뚜렷하게 증가하였다. 3. 세라믹 분말의 혼합처리는 모의 건물중을 증가시키는 것으로 나타났다. 4. 벼 유묘의 초장을 증가시키는 세라믹 분말의 추정 적정혼합비는 9.6%(240g)인 것으로 나타났다.