• The Korean Journal of Zoology
• /
• v.37 no.4
• /
• pp.514-523
• /
• 1994

꼬리명주나비(서ericinus montela) 조혈기관의 분포 및 미세구조를 광학현미경과 투과전자현미경을 이용하여 관찰하였다. 꼬리명주나비의 조혈기관은 흉부 제 2 · 3체절의 날개발생부위(imaginal wing disc)에 부착되었거나 인접해 있었다 각각의 조혈기관은 비세포성 기저 막으로 둘러싸인 여러 개의 조혈섬으로 구성되어 있었으며, 조혈 섬들은 compact islet(치밀하게 배열된 조혈섬)과 loose islet(느슨하게 배열된 조혈섬)으로 구분되었다. 혈구의 분화는 loose islet 내에서 진행되었으며, 시원세포로부터 원시혈구. 부정형혈구, 과립혈구, 소구혈구가 독자적 경로를 통해 분화되었다.

• Applied Microscopy
• /
• v.19 no.2
• /
• pp.119-137
• /
• 1989

It has been shown in this and earlier investigation that the turtle bladder mucosa has three main cell types on their mucosal surface. They are the granular cells, ${\alpha}$ CA cells, and ${\beta}$ CA cells. The three major transport mechanisms that occurs in the turtle bladder are sodium reabsorption, proton secretion, and bicarbonate secretion. In the present work the trans-port mechanisms by bladder epithelial cells of freshwater turtle, Pseudemys scripta, are summarized as follows. 1. The granular cells play an important role in sodium transport, while the ${\alpha}$ and ${\beta}$ CA cells do not appear to play a determining role in sodium transport. 2. It appears that the active sodium transport in the granular cells occurs in two-step process, implying that first, sodium diffuses into the cells, followed by an energy-dependent efflux step, which is catalyzed by the ouabain-sensitive Na-K ATPase. 3. The ${\alpha}$ type of CA cells are responsible for the proton secretion using the proton pump on the apical plasma membrane, while the ${\beta}$ type of CA cells are believed to be responsible for bicarbonate secretion. 4. When looked at under freeze-fracture electron microscopy, the apical plasma membrane of ${\alpha}$ cells have a characteristic population of rod-shaped intramembranous particles which are believed to be components of the proton pumps. Conversely, ${\beta}$ type of CA cells show rod-shaped particles in their basolateral plasma membranes, which is consistent with the proton absorptive, bicarbonate secretory mechanism. 5. In the turtle bladder, the ${\alpha}$ and ${\beta}$ type of cells are believed to be both responsible for proton transport, but in opposite directions.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.9 no.3
• /
• pp.638-646
• /
• 2005

In recent wireless communications, direct conversion transceiver or If sampling SDR-based receivers have being designed as an alternative to conventional transceiver topologies. In direct conversion receiver a.chitectu.e, the 1.equency/phase offset between the RF input signal and the local oscillator signal is a major impairment factor even though the conventional AFC/APC compensates the service deterioration due to the offset. To rover the limited tracking range of the conventional method and effectively aid compensation scheme in terms of I/Q channel imbalances, the frequency/phase offset compensation in RF-front end signal stage is proposed in this paper. In RF-front end, the varying phase offset besides the fixed large frequency/phase offset are corrected by using early-late phase compensator. A more simple frequency and phase tacking function in digital signal processing stage of direct conversion receiver is effectively available by an ingenious frequency/phase offset tracking method in RF front-end stage.

• Applied Microscopy
• /
• v.29 no.2
• /
• pp.201-209
• /
• 1999

Remodeling of epithelial cells during wound healing in the skin of the Korean fire-bellied toad, Bombina orientalis, were examined using the scanning and transmission electron microscopical analyses. Artificial wounds were induced on the dorsal surface of the skin by excision, and reared in special cages with normal diets for up to 31 days after injury. From 4 days after wounding, regenerated epithelial cells are more rapidly migrated to wounding area, and remodeling of tissue components are proceeded gradually. Especially, formation of basal lamina between regenerated epithelium and dermis, and reconstruction of cellular junctions such as desmosomes (among the regenerated epithelial cells) and hemidesmosomes (between basal epithelial cells and basal lamina) are detected through fine structural analysis from 10 days after injury. Parakeratosis of regenerated epithelial cells observed during 16 to 19 days after wounding.

• Journal of the Korean Data and Information Science Society
• /
• v.9 no.2
• /
• pp.179-188
• /
• 1998

Local polynomial regression estimation is the most popular one among kernel type regression estimator. In local polynomial regression function esimation bandwidth selection is crucial problem like the kernel estimation. When the regression curve has complicated structure variable bandwidth selection will be appropriate. In this paper, we propose a variable bandwidth selection method fully data driven. We will choose the bandwdith by selecting minimising estiamted MSE which is estimated by the pilot bandwidth study via croos-validation method. Monte carlo simulation was conducted in order to show the superiority of proposed bandwidth selection method.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.1857-1858
• /
• 2008

본 논문에서는 FCM 기반 RBF 뉴럴네트워크(FCM-RBFNN) 구조를 제안하고 PSO를 이용한 FCM-RBFNN의 구조 및 파라미터의 최적화 방법을 제시한다. 클러스터링 알고리즘은 퍼지 뉴럴 네트워크에서 멤버쉽함수의 중심점과 반경 등을 결정하는 학습에 일반적으로 사용된다. 제안된 FCM-RBFNN서는 방사기저함수로써 가우시안, 삼각형 타입 등의 정해진 형태를 사용하지 않고 데이터들 사이의 거리에 관계된 계산을 수행하는 FCM에 의해 결정된다. 기존의 RBFNN에서 후반부는 상수형태로써 방사기저함수의 선형결합으로써 표현되는 반면에 제안된 FCM-RBFNN의 후반부는 상수형, 선형, 2차식 등의 다양한 형태의 다항식으로 표현될 수 있으며 다항식의 계수는 WLSE를 이용하여 추정한다. FCM 기반 RBF 뉴럴 네트워크의 성능은 퍼지규칙의 수, 후반부 다항식의 차수 FCM의 퍼지화 계수에 의하여 결정기 때문에 FCM-RBFNN의 구조와 파라미터의 최적화가 요구된다. 본 논문에서는 PSO를 이용하여 FCM-RBFNN의 구조에 관련된 퍼지 규칙의 수, 후반부 다항식의 차수와 파라미터에 관련된 퍼지화 계수를 최적화한다. 또한 후반부 다항식의 계수는 WLSE를 사용하여 추정한다.

• Journal of the Korean Vacuum Society
• /
• v.16 no.5
• /
• pp.353-358
• /
• 2007

J-shaped superluminescent diodes (SLD) utilizing trench structure have been fabricated on the multiple quantum dots epi-structure with its ground state energy wavelength of $1.3\;{\mu}m$. It was observed that optical power was drastically increased up to 20 times in comparison with that of SLD without trench structure, The electroluminescence characteristics showed that the peak intensity of excited state was several ten times higher in the SLD with trench than without trench structure. It is explained that the optical power enhancement of J-shaped SLD with trench structure resulted from the drastic increase of peak intensity of excited state.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.15 no.12
• /
• pp.1044-1052
• /
• 1990

We have investigated the digital bit synchronization problem in baseband communication receiver systems using the Gauss-Markov estimation technique which is equivalent to the weighted least square method. The realized bit synchronizer, including the data detector, processes the input signal two dimensionally into the transition phase and data level under the white Gaussian noise environment. We have confrmed the realiation of the bit synchronizer via computer simulation. In addition, we have compared and evaluated the estimation error performance of the proposed method with that of the conventional DTTL method and of the minimum likelihood method.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2010.05a
• /
• pp.2021-2025
• /
• 2010

우리나라 대표적인 도서지역인 제주도는 대부분의 하천이 평상시 건천의 형태로 유지되며, 일정한 강우가 도달해야만 지표유출이 발생하는 경우가 대부분이다. 이와 같은 하천특성은 내륙과 매우 상이하여 일반적으로 사용되는 유역 수문해석 방법으로는 정확한 수문성분의 산정을 기대하기 어렵다. 이에 본 연구에서는 완전연동형 지표수-지하수 결합모형인 SWAT-MODFLOW을 이용하여 지표수 유출성분과 지하수 유동변화 및 지하수 개발까지 고려한 제주 표선유역의 통합수문성분 해석을 수행하였다. 특히 SWAT-MODFLOW에 포함된 양수모듈(MODFLOW의 well package 와 SWAT의 물이동 옵션 결합)을 이용하여 198개의 현 양수정 자료를 모의하였고, 현재 양수량, 현재양수량의 10배, 20배로 증대시켜 가며 수문성분 변화를 살펴보았다. 양수를 통해 지하수를 개발하여 사용하면 실질적으로 기저유출량의 감소가 발생하는 것으로 나타났고, 이러한 영향은 상류부 보다는 하류부에서 크게 작용할 것으로 판단된다. 그러나 제주도 지형적인 특성상 자연적으로 대수층으로 함양된 지하수가 대부분 바다로 유출, 손실되고 있으나 지하수를 양수할 경우, 손실량의 일부는 지하수 개발을 통해 효과적으로 사용됨으로써 제주 수자원의 추가 수자원확보량으로서 활용될 수 있을 것이다.

• Journal of Korean Society of Forest Science
• /
• v.72 no.1
• /
• pp.9-15
• /
• 1986

The taxonomy of the broad-leaf evergreen trees (4 genera, 5 species) of Lauraceae was studied by the morphological characteristics of stipules. The results obtained were summarized as follows; 1) The stipules of Lauraceae were arranged alternately with 5-31 stipules of simple leaf. The venations or stipules were basal reticulate and pinnated vein. The shapes of stipule blade were oblong, oblanceolate, rhomboid and oval. The stipule apex was acuminate and obtuse, the stipule base was attenuate, and the stipule margin was entire margin. The trichomes of stipules were sericeous, tomentose and villous. The five species of Lauraceae could be identified by the morphological characteristics of stipules. 2) The morphologically changing forms of stipule vein were classified into three groups; A form - the form of pinnate vein with the distinguished main vein (lozoste lancifolia), B form - the three vein grows into the form of basal reticulate vein (Neolitsea sericea, Cinnamomum japonicum and C. camphora), C form - the parallel vein grows into the form of basal reticulate vein (Marhilus thunbergii). 3) The changing forms of stipule's width from stipule "a" to "j" were three forms; (1) a>d>g>j form: C. japonicum, C. camphora and I. lancifolia, (2) a>cj,(aj,(a