http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
송원철,권종기,김욱,오창준,이종렬,송규상,박문양 에스케이텔레콤 (주) 1996 Telecommunications Review Vol.6 No.1
본 논문은 디지털 방식인 CDMA(Code Division Multiple Access)용 휴대폰의 중간 주파수 영역을 처리 하는 IF IC 의 설계에 관한 것이다. 이의 구조는 크게 수신부와 송신부 및 콘트롤부의 세 가지로 구성되어 있으며, 여기에는630KHz LPF, 4.95MHz BPF, 4-bit ADC, 8-bit DAC, Mixer, Clock generator, Power control 등의 회로가 포함되어 있다. 최근 휴대 기기 분야의 시장이 급속도로 성장함에 따라 저 전력 저가격의 제품이 요구되고 있으며, 이를위해 본 칩의 제작에는 전력 소모가 큰 Bipolar 공정 대신 ETRI의 2-poly, 2-metal 0.8 μm CMOS 공정을 사용하였다. 전체 칩의 크기는 5.0 x 4.2 mm2 이며, 칩의 소모 전력은 200mW 이다.
Directional raids by army ants as an adaption to patchily distributed food: a simulation model
송원철,김호영,이상임,Piotr G. Jablonski 한국통합생물학회 2018 Animal cells and systems Vol.22 No.4
A typical colony of Neotropical army ants (subfamily Ecitoninae) regularly raids a large area around their bivouac by forming a narrow directional column that can reach up to one hundred meters in length. The raid is finished and then relaunched 12–17 times, each time toward different orientation. After completing all bouts the colony relocates to a new area. A hypothetical alternative to this foraging mode is raiding radially and symmetrically by expanding the search front in every direction like a circular bubble. Using an existing agent-based modeling software that simulates army ants’ behavior, we compared the two possible modes of foraging in different food distributions. Regardless of the food patch abundance, the radial raiding was superior to the directional raiding when food patches had low quality, and the directional raiding was favorable when the patches were rich. In terms of energy efficiency, the radial raiding was the better strategy in a wide range of conditions. In contrast, the directional raiding tended to yield more food per coverage area. Based on our model, we suggest that the directional raiding by army ants is an adaptation to the habitats with abundance of high-quality food patches. This conclusion fits well with the ecology of army ants.