• Journal of Biosystems Engineering
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• 제21권3호
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• pp.315-324
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• 1996

This study was one of a series of studies on application of machine vision and image processing to extract the geometrical features of plants and to analyze plant growth. Several algorithms were developed to measure morphological properties of plants and describing the growth development of in-situ lettuce(Lactuca sativa L.). Canopy, centroid, leaf density and fractal dimension of plant were measured from a top viewed binary image. It was capable of identifying plants by a thinning top viewed image. Overlapping the thinning side viewed image with a side viewed binary image of plant was very effective to auto-detect meaningful nodes associated with canopy components such as stem, branch, petiole and leaf. And, plant height, stem diameter, number and angle of branches, and internode length and so on were analyzed by using meaningful nodes extracted from overlapped side viewed images. Canopy, leaf density and fractal dimension showed high relation with fresh weight or growth pattern of in-situ lettuces. It was concluded that machine vision system and image processing techniques are very useful in extracting geometrical features and monitoring plant growth, although interactive methods, for some applications, were required.

• 한국균학회지
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• 제42권2호
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• pp.133-137
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• 2014

본 연구에서는 간벌 처리에 따른 외생균근균의 군집 구조의 변화를 확인하기 위해 간벌지와 비간벌지에서 정량적으로 토양을 채취하여 간벌에 따른 외생균근균의 종 다양성, 종 수, 외생균근 수, 군집 내 종 구성을 비교하였다. 분석 결과 간벌지와 비간벌지는 공통적으로 Russula 속이 우점하고 있으나, 간벌 처리 후 산림 토양의 외생균근균 군집의 종 구성이 달라지고 종 수가 증가되는 것을 확인하였다. 본 연구결과는 간벌이 산림 생태계의 지상부 뿐만 아니라 외생균근균과 같은 토양속의 미생물의 군집 구조에도 유의미한 영향을 미치는 중요한 요인이라는 것을 보여주고 있다.

• 대한의용생체공학회:의공학회지
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• 제16권3호
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• pp.337-344
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• 1995

방사선 치료에 있어서 치료전 및 치료도중에 치료부위를 확인하기 위한 수단으로 보편적으로 사용되고 있는 포탈필름은 높은 에너지를 이용하여 촬영되는 것이므로 영상이 매우 흐리며 어둡다는 구조적인 문제점이 있다. 이러한 영상을 개선하기 위하여는 치료필드와 그 주변필드로 영상을 먼저 분할한 후, 각 필드 별로 영상처리를 해야만 한다. 본 연구에서는 소벨 탐지자, 레이블링 기법을 이용하여 최적의 문턱치를 찾아내어 포탈영상을 분할 한 후 형태학적 세선화기법들을 적용하여 포탈영상 분할하는 알고리즘을 제안하였다. 이 알고리즘은 포탈영상에서 불필요한 에지들은 제거하고 치료필드 에지만을 탐지하며 촬영조건이 수시로 변하는 임상적 환경에서 얻어지는 포탈영상들에 적용하여도 균일한 결과를 얻을 수 있다.

• 대한전기학회논문지:시스템및제어부문D
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• 제51권12호
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• pp.577-582
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• 2002

The objective of this paper is to produce a weighted graph map for path-planning of an autonomous mobile robot(AMR) based on the measurements from a single ultrasonic sensor, which are acquired when the autonomous mobile robot explores unknown indoor circumstance. The AMR navigates in th unknown space by following the wall and gathers the range data using the ultrasonic sensor, from which the occupancy grid map is constructed by associating the range data with occupancy certainties. Then, the occupancy grid map is converted to a weighted graph map suing morphological image processing and thinning algorithms. the path- planning for autonomous navigation of a mobile robot can be carried out based on the occupancy grid map. These procedures are implemented and tested using an AMR, and primary results are presented in this paper.

• Clinical and Experimental Reproductive Medicine
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• 제38권3호
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• pp.148-152
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• 2011

Objective: Laser-assisted intracytoplasmic sperm injection (LA-ICSI), also known as micro-opening or thinning of the zona pellucida (ZP) prior to ICSI, may help to reduce mechanical damage to the oocyte during the procedure. The aim of the present study was to evaluate and analyze the efficacy of our institutional LA-ICSI program, which features laser-assisted ZP thinning prior to ICSI, in comparison with conventional ICSI (C-ICSI), performed on patients with different clinical characteristics. Methods: Patients undergoing a total of 212 ICSI cycles were randomly divided into an LA-ICSI group (106 cycles) and a conventional ICSI group (106 cycles). To reduce tissue damage, we thinned the ZP by approximately 70%, using a laser, before ICSI. Patients thus treated formed the LAICSI group. Comparisons included the morphological quality of transferred embryos, blastocyst development of the remaining embryos, and clinical pregnancy, in terms of ICSI method and patient characteristics. Results: Fertilization, development of remaining embryos, and pregnancy rate were significantly higher in the LA-ICSI group compared with the C-ICSI group. Fertilization, embryonic development, and the pregnancy rate were all improved in younger patients (<38 years of age) and in those who underwent a low number of IVF-ET attempts (<3 trials). In addition, the pregnancy rate was increased in older patients. Conclusion: LA-ICSI may be useful in improving the chance of pregnancy in all ICSI patients.

• Fibers and Polymers
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• 제2권3호
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• pp.129-134
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• 2001

Liquid crystalline (LC) poly(ethylene terephthalate-co-2(3)-chloro-1,4-phenylene terephthalate) (50/50, mole/mole) [PECPT] was synthesized and blended with polycarbonate (PC). LC properties of PECPT and thermal, morphological, and rheological behaviors of the PECPT/PC blend were studied. PECPT showed the nematic LC phase and much longer relaxation time than poly(ethylene terephthalate) (PET). The apparent melt viscosity of PECPT was one third of that of FET. An abrupt torque change was observed during the blending process due to the orientation of LC domains. For the blends containing 10~30 wt% of PECPT, the complex viscosities were higher than that of PC. As PECPT content increases above 40 wt%, shear thinning was observed. The lowest complex viscosity was obtained at 40~50 wt%. Transesterification of PECPT and PC was confirmed by the selective chemical degradation of carbonate groups in PC.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.900-903
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• 1996

The objective of this paper is to make the weighted graph map for path planning using the ultrasonic sensor measurements that are acquired when an A.M.R (autonomous mobile robot) explores the unknown circumstance. First, The A.M.R navigates on unknown space with wall-following and gathers the sensor data from the environments. After this, we constructs the occupancy grid map by interpreting the gathered sensor data to occupancy probability. For the path planning of roadmap method, the weighted graph map is extracted from the occupancy grid map using morphological image processing and thinning algorithm. This methods is implemented on an A.M.R having a ultrasonic sensor.

• 보존과학회지
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• 제2권2호
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• pp.15-24
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• 1993

To understand the morphological change of ancient woods, samples classified by cell type, burial environment and species were collected and observed using microscopy. Decay of wood by cell type could classified into two types. First, degraded secondary wall was formed granular residues in $S_2$ layer and was remained $S_3$ layer and compound middle lamella. Second, the cell wall was slightly degraded and cracked in secondary wall. A gradual thinning of cell wall was occured. The compound middle lamella was separated from secondary wall. The resistance of degradation is increased at vessels, parenchyma, and tracheid and wood fiber in the order named. The type of degradation by species could be classified into four types. Overall degradation type; the degradation of cell wall is usually heavy and the extent of degradation Varies by part of the same sample. Partial degradation type ; this type shows severely different decay type by part of the sample. Nondegraded cells were mixed with degraded cells on the same sample. Erose degradation type ; thinning of the cell wall was occoured and the degradation type was different by part. Slight degradation types ; secondary wall was slightly degraded, cracked and separated from compound middle lamella. Considering different type of burial environment, dry wood was similiar to sound wood and slightly decayed. Waterlogged and peat burial wood was heavilydecayed. Between species of under the same environment, decay type and extent were diferentiated from each other.

• 대한수의학회지
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• 제42권3호
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• pp.429-436
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• 2002

Hydrocepbalus may be an acquired or a congenital condition. We have studied the macroscopic and microscopic changes in the hydrocephalus of an inbred Sprague-Dawley rat at postnatal week 8. The animal suspected with the hydrocephalus showed clinical syndromes such as depression, severe ataxia, eye abnormalities, dome-shaped head, and persistent fontanelle. With the postmortem examination, the suspected animal was clearly revealed as a severe internal hydrocephalus. In this animal, severe ventriculomegaly was limited to the third and lateral ventricles, and cortical thining was most apparent in the parieto-occipital region. With the routine histological examination, brain tissue showed aqueductal obstruction, thinning of the cerebral cortex, severe ependymal damage, subependymal edema, damage of choroid plexus of fourth ventricle, enlarged cortical vessels, and expanded ventricles. Aqueductal obstruction was observed with the appearance of simple stenosis at the level of rostral colliculus. Subsequently, the other structures of brain such as septal nucleus, caudate nucleus, and hippocampus etc. were abnormally reconstructed by hydrocephalus. This study suggests that the hydrocephalus can be taken place by primary aqueductal obstruction and this type of hydrocephalus is classified as uncommunicating type. Though the mechanism of aqueductal obstruction is not clear, the morphological studies of this case may be helpful for the further study of hydrocephalus.

• Macromolecular Research
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• 제13권3호
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• pp.243-252
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• 2005

The effect of the vinyl acetate (VA) content on the thermal, viscoelastic, rheological, morphological and mechanical behaviors in various blends of ethylene-vinyl acetate (EVA)/ethylene-$\alpha$-olefin copolymers was investigated using 28, 22 and $15 mol\%$ of VA in EVA. In the DSC melting and crystallization thermograms of all of the EVA systems blended with ethylene-$\alpha$-olefin copolymers, discrete peaks were observed which were related to the constituents. In the dynamic mechanical thermal analysis, the storage modulus increased with increasing content of ethylene-$\alpha$-olefin copolymers. In addition, the transition regions relating to the tan bpeaks varied with the VA content. The crossover point between G' and G" varied depending on the VA contents, and shear-thinning was more prominent in the EVA/EtBC system. In the SEM investigation, a discrete phase morphology was observed in both the EVA/EtBC and EVA/EtOC blends, but the contrast improved with decreasing VA content. However, the tensile strength and modulus improved, but the elongation at break reduced with decreasing VA content, implying that the ethylene-$\alpha$-olefin copolymers play the role of reinforcing materials. Thus, the EVA and ethylene-$\alpha$-olefin components in the copolymers are immiscible in the molten and solid states, but are nevertheless mechanically compatible.