• Proceedings of the KIPE Conference
• /
• 2014.07a
• /
• pp.490-491
• /
• 2014

최근 단상 태양광 인버터는 태양판과 대지사이에 나타나는 기생 커패시터에서 발생하는 EMI를 감소시키기 위한 연구가 활발히 진행되고 있다. 본 논문에서는 계통연계 인버터의 EMI 개선 방안을 고찰하고, 이를 적용한 고효율 단상 풀 브릿지 인버터와 지전류 감소를 위한 새로운 방안을 제시한다.

• Proceedings of the KIEE Conference
• /
• 2002.11a
• /
• pp.187-189
• /
• 2002

일반적으로 상용주파수에서의 대지는 입력전류의 크기에 따라 일정한 저항체로 다루어 질 수 있으며, 접지도체 임피던스도 무시할 수 있고 접지도체 전체가 등전위로 볼 수 있다. 그러나 써어지 전류 유입시에는 주파수가 수백 MHz 이므로 접지도체 임피던스에 의한 전압강하가 크게 될 뿐 아니라 써어지 전류 유입점의 도체전위가 매우 많이 상승하게 된다. 따라서, 본 논문에서는 운전중인 변전소 안전측면에서 접지임피던스와 보폭 및 접촉전압 등의 위험전압측정을 통한 안전성을 검토하였다.

• Proceedings of the Korean Society for Rock Mechanics Conference
• /
• 1995.03a
• /
• pp.101-107
• /
• 1995

일본은 Pacific plate, Philippine plate, Eurasian plate 및 American plate 가 서로 접해 있는 판 경계부에 위치하며 내륙에는 많은 활단층(active fault)이 분포하고 있다. 이러한 활단층은 제4기 이후 단층 활동을 반복하면서 엄청난 재해를 동반하는 대지진의 발생과 함께 지표면에 지진 단층(earthquake fault)의 출현을 초래했다. 따라서 활단층 연구는 지진 예지, 지진 위험도 연구에 매우 중요한 분야가 되어왔다. (중략)

• Proceedings of the Korean Society of Disaster Information Conference
• /
• 2022.10a
• /
• pp.207-208
• /
• 2022

본 연구의 접지는 매설깊이나 봉의 개수에 따라 다소 차이가 있으며 시공비가 가장 저렴한 반면 신뢰도가 낮은 접지방식으로 장, 단점을 갖고 있었다. 대형 건축물에 대부분 적용하는 경우로 접지방식에서 대형화가 이루어짐으로 다소 신뢰가 있는 접지 시스템을 구축하고 있었다.

• Korean Architects
• /
• s.660
• /
• pp.40-43
• /
• 2024

월간 <건축사> 4월 호의 표지를 장식한 '차이커뮤니케이션 사옥'은 강남구 학동대로 뒤쪽에 있는 광고 회사의 사옥이다. 이 건축물은 여백과 절제를 통해 단순하면서도 정갈한 입면을 구현해 내어, 새롭고 오래된 건축물이 혼재된 강남구에서 그 자체로 심플하면서도 힘 있게 자리한다. 제한적인 대지 규모에서, 개개인의 창의성을 중요시한 오픈형 사무공간에 도시와 자연을 동시에 담아내 다양한 외부공간을 접하게 한 차이커뮤니케이션 사옥을 설계한 박일훈 건축사(반 건축사사무소), 지난 3월 12일, 그를 만나 건축적 목표 등의 이야기를 직접 들어봤다.

• Journal of Sensor Science and Technology
• /
• v.10 no.4
• /
• pp.250-258
• /
• 2001

In this study, a lightning warning system (LWS) which can predict a lightning return stroke is developed, and the LWS is based on the measurement of electric field intensity at the ground level. The LWS consist of a rotation-type field mill as an electric field sensor, an impedance changer, a two-stage amplifier, and a microprocessor unit. From the calibration experiment, the frequency bandwidth and the maximum resolution of the LWS are $DC{\sim}200\;[Hz]$ and 73 [V/m], respectively. Also, the LWS can measure the electric field strength caused by a thunderstorm up to 18.7 [kV/m] at the ground. To ensure the sensing ability of the developed LWS in an actual situation, computer simulation using thundercloud models was carried out, and the result showed that the LWS can monitor the movement of thunderclouds within 6 [km] from the observation site.

• Economic and Environmental Geology
• /
• v.27 no.2
• /
• pp.191-199
• /
• 1994

We have developed an algorithm based on the method of integral equations to simulate the magnetotelluric (MT) responses of three-dimensional (3-D) bodies in a layered half-space. The inhomogeneities are divided into a number of cells and are replaced by an equivalent current distribution which is approximated by pulse basis functions. A matrix equation is constructed using the electric Green's tensor function appropriate to a layered earth, and is solved for the vector current in each cell. Subsequently, scattered fields are found by integrating electric and magnetic Green's tensor functions over the scattering current About a 3-D conductive body near the earth's surface, interpretation using 2-D transverse electric modeling schemes can imply highly erratic low resistivities at depth. This is why these routines do not account for the effect of boundary charges. However, centrally located profiles across elongate 3-D prisms may be modeled accurately with a 2-D transverse magnetic algorithm, which implicitly includes boundary charges in its formulation. Multifrequency calculations show that apparent resistivity and impedance phase are really two complementary parameters. Hence, they should be treated simultaneously in broadband MT interpretation.

• Journal of the Korean Geographical Society
• /
• v.51 no.4
• /
• pp.473-490
• /
• 2016

This study aims to analyze the regional geomorphology of the Chugaryeong Tectonic Valley which has been one of the most important areas for Korean geomorphological research. Though the Chugaryeong Tectonic Valley has been thought important for the tectonic settings and orographic processes in Korea, geomorphological and geological discussions still are sustaining for finding out evidences of the settings. The Chugaryeong valley region has many geomorphic themes such as tectonic structure, volcanics, river, mountain, terrace, lake and sediment layers. The research of the valley focuses on the comprehensive analysis of the previous references mainly including geomorphic naming, geomorphology and geology, and history of the study for estimating the origin of tectonic valley, formation of the lave plateau, change of river structure by dissection, restoration of the landform before lava eruption, and the processes and age dating of the various landforms. Conclusively, the Chugaryeong Tectonic Valley may be recognized as the linear region of the tectonic and volcanic landforms with other various applied geomorphic settings.

• Korean Journal of Soil Science and Fertilizer
• /
• v.17 no.4
• /
• pp.343-348
• /
• 1984

Variation of soil properties within mapping unit of lava plain soils was statistically summarized. Properties such as particle size distribution, moisture retention, color, pH, and CEC are relatively unaffected by soil management while Na, K, base saturation, and available $P_2O_5$ most affected by management. These soils were correctly classified with regard to order at 66.5, to greatgroup at 56.0, and to series at 43.8%. CV values greater than 90% could be symptomatic of skew distribution. Distributions of sand content and some chemical properties were log-normal.

• Korean Journal of Environmental Biology
• /
• v.19 no.4
• /
• pp.270-277
• /
• 2001

To observe the stimulating effect of low dose ${\gamma}$ radiation on the dormancy breaking and growth, microtubers induced in vitro of two potato (Solanum tuberosum L. cv. Dejima and cv. Superior) cultivars with different storage duration were irradiated with ${\gamma}$ radiation at the dose of $0.5{\sim}30$ Gy. Sprouting rate, growth and tuber yield of ‘Dejima’ microtuber were increased by ${\gamma}$ radiation in the range of $2{\sim}16$ Gy. In the microtuber of ‘Superior’, the sprouting rate was promoted by 2 Gy and 4 Gy irradiation, and the growth and tuber yield by 0.5 Gy and 4 Gy irradiation. There were not that much difference in chlorophyll content of potato plantlet by the low dose ${\gamma}$ irradiation. These results suggested that low dose ${\gamma}$ radiation stimulated the dormancy breaking and potato growth.