• 제목/요약/키워드: m-structure

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지리산 서부지역에서 고도와 임령에 따른 임분 구조 변화 (Stand Structure Change in Different Aged Stands Along Altitudinal Gradients in the Western Part of Mt. Chiri)

  • 박필선;송정임;김명필;박학기
    • 한국산림과학회지
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    • 제95권1호
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    • pp.102-112
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    • 2006
  • 고도와 임령에 따른 임분 구조 변화를 알아보기 위하여 지리산 서부 지역의 해발 고도 약 400 m, 800 m, 1,000 m, 1,300 m 지역에 위치한 임분에서 $20m{\times}20m$ 방형구를 각각 3-8개씩 설치하고 흉고직경 2.5cm 이상인 임목을 대상으로 매목조사를 실시하였다. 소나무(Pinus densiflora Siebold & Zucc.)와 구상나무(Abies koreana Wilson)의 연령을 바탕으로 임령을 추정한 후 고도와 임령에 따른 수종 구성과 임분 구조를 분석하였다. 임분들은 고도에 따라 다른 수종 구성을 보였으며, 침엽수의 경우 고도 400 m 지역에서는 소나무가, 1,300 m 지역에서는 구상나무가 우점수종으로 나타났다. 참나무류는 낮은 지역의 굴참나무(Quercus variabilis Blume) 에서 고도가 높아짐에 따라 800 m 지역에서는 졸참나무(Quercus serrata Thunb. ex Murray), 1,000 m 이상에서는 신갈나무(Quercus mongolica Fisch. ex Ledeb.)로 우점수종이 변하였다. 직경분포는 고도에 따른 차이가 크지 않았으나, 임분의 상층 수고는 고도가 높아짐에 따라 낮아져, 1,000 m 이상에서는 수고 20 m 이상의 임목이 거의 나타나지 않았다(P<0.0001). 고도 400 m 지역의 소나무 우점 임분은 대략 30-40년과 70년생의 두 연령 그룹을 가졌으며, 고도 800 m 지역의 졸참나무 우점 임분의 임령은 약 30년인 것으로 추정되었다. 고도 1300 m에 지역에서 신갈나무 우점 임분은 상층 임목이 들어온 후 약 70년, 구상나무 우점 임분은 140년 이상된 것으로 추정되었으며, 직경분포는 임령에 따라 소나무에서 신갈나무, 신갈나무에서 구상나무로 우점종의 변화 가능성을 보여주었다.

Acoustic Species Identification of Korean Myotis Bats (Chiroptera: Vespertilionidae)

  • Yoon, Kwang Bae;Rahman, M. Mafizur;Park, Yung Chul
    • Journal of Forest and Environmental Science
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    • 제32권1호
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    • pp.68-73
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    • 2016
  • We investigated structure and intensity of 267 echolocation calls that were collected from the five Korean Myotis species (M. nettereri, M. petax, M. ikonnikovi, M. macrodactylus and M. formosus). All the Myotis species produced typical FM call pattern with similar echolocation call shapes and outer shapes, producing steep, downward frequency-modulated calls. A pulse has two harmonies, which consist of the first harmony with wider bandwidth and the second harmony with narrower bandwidth. The PF of the first harmony is higher than that of the second harmony. The typical FM call structure, with two harmonies and wide bandwidth, might be highly related to fast flying and wide screening in the dense forests. In classification of the echolocation calls by DFA, most of calls from the five species could be well correctly classified. All calls of M. nettereri (100% of 17 calls), M. formosus (95.5% of 22 calls) and M. ikonnikovi (85.7% of 70 calls) could be well discriminated from those of the other species, whereas calls of M. petax and M. macrodactylus could be discriminated by 70.4% of 98 calls and 76.7% of 60 calls, respectively. Our results indicate that the five Korean Myotis species can be well identified by the echolocation calls with high correct classification by DFA.

저자동시인용분석을 위한 복수저자 기여도 산정 방식의 비교 분석 (A Comparative Analysis on Multiple Authorship Counting for Author Co-citation Analysis)

  • 이재윤;정은경
    • 정보관리학회지
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    • 제31권2호
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    • pp.57-77
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    • 2014
  • 학문연구에서 공저가 빈번해짐에 따라서 저자 단위의 지적 구조 분석을 수행할 때 복수저자의 기여도 산정 방식이 중요한 고려사항이 되고 있다. 이 연구에서는 복수저자 기여도 산식에 따른 상관분석, 다차원척도법, 패스파인더 네트워크의 차이를 비교 분석해보았다. <한국건축학회지: 계획계>에 2003년부터 2008년까지 발표된 2,014편의 논문을 대상으로 여섯 가지 복수저자 기여도 산식을 적용해보았다. 첫째는 제1저자만 고려하는 산식(m1), 둘째는 모든 공저자 대등 산식(m2), 셋째는 균등분할 산식(m3), 넷째는 합계 1이 되는 차등 산식(m4), 다섯째는 합계 1 이상 2 이하가 되는 차등 산식(m5), 여섯째는 제1저자 가중 산식(m6)이다. 이중에서 m1은 제1저자 이외의 공저자를 모두 무시하는 반면 m2는 제1저자와 다른 공저자를 동등하게 기여도가 1인 저자로 취급하므로 두 산식이 가장 양 극단의 방식인 것으로 분석되었다. 상관분석과 다차원척도분석을 수행할 때 m1을 제외한 다섯가지 산식(m2~m6)의 결과를 비교해본 결과 m3, m4, m5는 상대적으로 유사한 결과를 도출하는 것으로 나타났다. 그러나 패스파인더 네트워크로 지적 구조를 시각화한 결과에서는 복수저자 기여도 산식을 달리함에 따라 변경되는 한 두 링크의 차이가 전체 네트워크 구조의 현저한 차이를 낳을 수 있는 것으로 나타났다. 저자 군집에 대한 내적 타당도 측정 결과에서는 제1저자 가중 산식(m6)이 좋은 성능을 보였다. 비교 분석 결과 여섯 가지 복수저자 기여도 산정 방식 중 유사한 방식들을 구분할 수 있었으며, 특히 지적 구조를 네트워크로 표현하는 경우에 산정 방식의 차이가 더 큰 영향을 끼치는 것으로 드러났다.

중국(中國) 연변지구(延邊地區) 조선족(朝鮮族)마을의 구성(構成) 룡정시 지신향 장재촌을 대상으로 (Tie Spatial Structure of Ch'ang-ts'ai-ts'un Village A Case Study on a Rural Village of Korean Immigrants in Yen-pien Area of China)

  • 이규성
    • 건축역사연구
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    • 제3권1호
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    • pp.83-99
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    • 1994
  • Ch'ang-Ts'al-Ts'un is a rural Village near Lung-jing City in Yen-pien Korean Autonomous Province of China. It was formed about 100 years ago by Korean Immigrants and has been developed maintaing the characteristics of traditional Korean architecture. Therefore investigating the spatial structure of this village is a meanigful work to confirm and explore one branch of Korean architecture. This study aims at analyzing the spatial structure of the village using direct data collected from the field work and indirect data from books and maps. The field work consists of on-the-site survey of the village layout, interviews of residents, observation notes and photography. Ch'ang-Ts'ai-Ts'un is located 360-370 m high above the sea level and at the side of a long valley. A river flows in the middle of the valley and relatively flat arable land exists at the both sides of the river. The location of the village related to the surrounding river and mountains suggests that the site of the village was chosen according to Feng-Shui, Chinese and Korean traditional architectural theory. The main direction of the house layouts is South-western. The village has been growing gradually until today. Therefore it is meaningful to make the village layout before Liberation(1946 A.D.) because the characteristics of Korean architecture prevailed more in that period. The area of the previous village is limited to the west side of the creek. New houses were later added to the east of the creek, forming a 'New Village'. Previously the village was composed of 3 small villages: Up, Middle and Down. Also the main access roads connecting the village with the neighboring villages were penetrating the village transversely. Presently the main access road comes to the village longitudinally from the main highway located in front of the village. The retrospective layout shows the existence of well-formed Territory, Places and Axes, thus suggesting a coherent Micro-cosmos. The boundary of imaginery territory perceived by present residents could be defined by linking conspicous outside places sorrounding the village such as Five-mountains, Front-mountain, Shin-dong village, Standing-rock, Rear-mountain and Myong-dong village. Inside the territory there are also the important places such as Bus-stop, Memorial tower of patriots, Road-maitenance building and the village itself. And inside it 5 transverse and 1 longitudinal axes exist in the form of river, roads and mountains. The perceived spatial structure of the village formed by Places, Axes and Territory is geometrical and well-balanced and suggests this village is fit for human settlement. The administrative area of the village is about 738 ha, 27 % of which is cultivated land and the rest is mountain area. Initially the village and surrounndings were covered with natural forest But the trees have been gradually cut down for building and warning houses, resulting in the present barren and artificial landscape with bare mountains and cultivated land. At present the area of the village occupied by houses is wedge-shaped, 600 m wide and 220 m deep in its maximum. The total area of the village is $122,175m^{2}$. The area and the rate of each sub-division arc as follow. 116 house-lots $91,465m^{2}$ (74.9 %) Land for public buildings and shops $2,980m^{2}$ (2.4 %) Roads $17,106m^{2}$ (14.0 %) Creek $1,356m^{2}$ (1.1 %) Vacant spaces and others $9,268m^{2}$ (7.6 %) TOTAL $122,175m^{2}$ (100.0 %) Each lot is fenced around with vertical wooden pannels 1.5-1.8 m high and each house is located to the backside of the lot. The open space of a lot is sub-divided into three areas using the same wooden fence: Front yard, Back yard and Access area. Front and back yards are generally used for crop-cultivation, the custom of which is rare in Korea. The number of lots is 116 and the average size of area is $694.7m^{2}$. Outdoor spaces in the village such as roads, vacant spaces, front yard of the cultural hall, front yard of shops and spacse around the creek are good 'behavioral settings' frequently used by residents for play, chatting, drinking and movie-watching. The road system of the village is net-shaped, having T-junctions in intersections. The road could be graded to 4 categories according to their functions: Access roads, Inner trunk roads, Connecting roads and Culs-de-sac. The total length of the road inside the village is 3,709 m and the average width is 4.6 m. The main direction of the road in the village is NNE-SSE and ESE-WNW, crossing with right angles. Conclusively, the spatial structure of Ch'ang-Ts'ai-Ts'un village consists of various components in different dimensions and these components form a coherent structure in each dimension. Therefore the village has a proper spatial structure meaningful and appropriate for human living.

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Dual-Gate Surface Channel 0.1${\mu}{\textrm}{m}$ CMOSFETs

  • Kwon, Hyouk-Man;Lee, Yeong-Taek;Lee, Jong-Duk;Park, Byung-Gook
    • Journal of Electrical Engineering and information Science
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    • 제3권2호
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    • pp.261-266
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    • 1998
  • This paper describes the fabrication and characterization of dual-polysilicon gated surface channel 0.1$\mu\textrm{m}$ CMOSFETs using BF2 and arsenic as channel dopants. We have used and LDD structure and 40${\AA}$ gate oxide as an insulator. To suppress short channel effects down to 0.1$\mu\textrm{m}$ channel length, shallow source/drain extensions implemented by low energy implantation and SSR(Super Steep Retrograde) channel structure were used. The threshold voltages of fabricated CMOSFETs are 0.6V. The maximum transconductance of nMOSFET is 315${\mu}$S/$\mu\textrm{m}$, and that of pMOSFET is 156 ${\mu}$S/$\mu\textrm{m}$. The drain saturation current of 418 ${\mu}$A/$\mu\textrm{m}$, 187${\mu}$A/$\mu\textrm{m}$ are obtained. Subthreshold swing is 85mV/dec and 88mV/dec, respectively. DIBL(Drain Induced Barrier Lowering) is below 100mV. In the device with 2000${\AA}$ thick gate polysilicon, depletion in polysilicon near the gate oxide results in an increase of equivalent gate oxide thickness and degradation of device characteristics. The gate delay time is measured to be 336psec at operation voltage of 2V.

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고체추진제의 Thermal Structure 분석에 관한 실험적 연구

  • 채재우;문종인
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 1996년도 제6회 학술강연회논문집
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    • pp.109-117
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    • 1996
  • Strand Burner 내에 설치되는 추진제에 10$\mu\textrm{m}$굵기의 Thermocouple을 설치하여 각 압력하에서의 연소속도 및 연소시의 Thermal Structure의 정보를 얻는 방법과 러시아의I.C.P에서 공동실험을 통하여 얻은 60%의 니트로글리세린과 40%의 니트로셀룰로오스를 혼합한 더블베이스 추진제 및 AP와 에폭시수지를 혼합한 간이 Composite형 추진제의 Thermal Structure를 조사한다.

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