• 대한원격탐사학회지
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• 제34권4호
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• pp.639-647
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• 2018

This paper presents TerraSAR-X and KOMPSAT-5 sigma nought variation according to season and antenna observation configuration in Mongolia. Two types of landcover including bare surface and cropland were examined. The seasonal variation of sigma nought in cropland was about 7 dB and particularly a significant sigma nought reduction occurred after harvest. On the contrary, the Mongolia bare surface provides a consistent sigma nought values for several years with an annual variation less than 2.5 dB of standard deviation. However, the bare soil was relatively sensitive to look-direction (or ascending or descending mode) as well as incidence angle while the cropland was almost independent of antenna look-direction and small incidence angle changes. Although the look-directional variation of bare surface sigma nought was observed in this study, the look-direction anisotropic nature of the surface was not well examined. A further study would be required to account for this feature with various SAR observation configurations.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 춘계학술발표대회 논문집
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• pp.97-100
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• 2000

A FEA(finite element analysis) model was proposed to study stress and strain distributions in thick composites with various types of fiber waviness under tensile and compressive loadings. Three types of model were considered in this study: uniform fiber waviness, graded fiber waviness and localized fiber waviness models. In the analysis, both material and geometrical nonlinearities due to fiber waviness were incorporated into the model utilizing energy density and incremental method. The strain distributions of uniform fiber waviness model were strongly influenced whereas the stress distributions were little influenced by fiber waviness. The stress and strain distributions of graded and localized fiber waviness models showed more complex distributions than those of uniform fiber waviness model due to the variation of fiber waviness along the thickness and length directions. It was concluded that the stress and strain distributions of composites with fiber waviness were significantly affected by types of fiber waviness.

• Journal of Forest and Environmental Science
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• 제34권2호
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• pp.145-152
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• 2018

Quantification of Carbon stock has become in the contest of changing climate and mitigation potential of forests. Two different forest types, Dry Shiwalik Sal Forest and Moist Shiwalik Sal Forest in Barkot and Lachchiwala of Doon Valley, Western Himalaya are selected for the study. Volume equations, destructive sampling and laboratory analysis are done to estimate the carbon stock in different carbon pools like trees, shrubs, herbs and soils. Considerable variations are observed in terms of carbon stocks in different forest types. In Dry Shiwalik Sal Forest, carbon stock density varied between 129.81 and $136.00MgCha^{-1}$ while in Moist Shiwalik Sal Forest, carbon stock density ranged from 222.29 to $271.67MgCha^{-1}$. Tree species like Shorea robusta, Syzigium cumini, Miliusa velutina, Acacia catechu, and Mallotus philippensis had significant role in carbon sequestration. Shorea robusta had contributed highest in carbon stock due to highest density. Total of 2,338,280.165 Mg carbon stock was estimated in all the forest types.

• Journal of Plant Biology
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• 제14권3호
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• pp.29-35
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• 1971

Various types of short culm rice mutants were obtained by means of gamma-ray irradiation. In the present paper morphological observation and analysis of silicate content of the mutants are reported. 1. Short culm type had more useful characters than bushy and dwarf types. 2. In short culm and bushy types the number of nodes both above and under ground was similar to the mother varieties, while in dwarf type it decreased. 3. In short culm types the variation of length of above-ground culm and internodes tended to vary relattive to the mother varieties. 4. Positive correlation was found between culm length and the first and fourth internode length in short culm type. 5. Silicate content increased in short culm type-the increment being variety specific.

• Journal of Plant Biology
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• 제28권4호
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• pp.305-315
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• 1985

Morphological variations within the species of Scenedesmus in Korea, S. armatus and 2 strains of S. quadricauda were investigated. Taxonomic characters such as length of long spine, ridge, unicell-colony transformation, and colony types were compared. The length of long spine was constant, whereas the distribution of the spine varied with the age of culture. Ridge and short spine in S. armatus occurred constantly, whereas those in S. quadricauda varied with the composition of the media and age of culture. Strains CY-1 and CY-2 showed 6 different colony types in the stationary culture, whereas S. armatus formed only two types, armatus and armatus-longus types. All strains showed unicell-colony transformation. The cell became minimum when the daughter cell was released, and reached maximum at division.

• The Korean Journal of Ecology
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• 제23권4호
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• pp.309-313
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• 2000

Since specific types and physical characteristics of anuran calls can represent reproductive qualities of a calling male, anuran calls have been studied in context of mate choice. We in here report call types of Rana dybowskii and their variations from two different recording sites. Calls of R. dybowskii are classified to three types based on their physical characteristics and behavioral observations; 'A-call'functions to advertise locations of a calling male and to attract potential mates. A territorial male emits 'B-call'only during male-male interaction. 'C -call'is released when a male frog was clasped by another male. The A-call from two recording sites, Miwon and Wonju, shows high variations in their call characteristics.

• 대한교통학회지
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• 제14권1호
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• pp.135-154
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• 1996

This paper presents a heuristic algorithm for classifying vehicles using a single loop detector. The data used for the development of the algorithm are the frequency variation of a vehicle sensored from the circle-shaped loop detectors which are normal buried beneath the expressway. The pre-processing of data is required for the development of the algorithm that actually consists of two parts. One is both normalization of occupancy time and that with frequency variation, the other is finding of an adaptable number of sample size for each vehicle category and calculation of average value of normalized frequencies along with occupancy time that will be stored for comparison. Then, detected values are compared with those stored data to locate the most fitted pattern. After the normalization process, we developed some frameworks for comparison schemes. The fitted scales used were 10 and 15 frames in occupancy time(X-axis) and 10 and 15 frames in frequency variation (Y-axis). A combination of X-Y 10-15 frame turned out to be the most efficient scale of normalization producing 96 percent correct classification rate for six types of vehicle.

• The Korean Journal of Ecology
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• 제21권3호
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• pp.301-307
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• 1998

Intraspecific and interspecific isozyme variations and their relationship of 16 local populations in 3 species of Phyllostachys, that is, P. bambusoides, P. nigra var. henonis and P. pubescens were investigated by multi-variate analysis. Leaf isozymes of Phyllostachys such as 6-PGD (6-phosphogluconate dehydrogenase), MDH (malate dehydrogenase), PGI (phosphoglucoisomerase), PRX (peroxidase), PGM (phosphoglutamase), IDH (isocitrate dehydrogenase) showed electrophoretic variations in the number of zymotypes (7, 6, 6, 9, 3 and 5, respectively). In the cluster analysis on the isozymic characteristics, 16 populations were classified into 3 species at the euclid genetic distance of 2.041. P. nigra var. henonis and P. bambusoides were clustered first at 2.813 and then P. pubescens at 3.001. So far, 3 local types of intraspecific ariation were found in P. nigra var. henonis and P. bambusoides.

• Journal of international Conference on Electrical Machines and Systems
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• 제2권1호
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• pp.45-50
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• 2013

This paper presents design of induction motor in very low temperature for LNG main cargo pump and comparison of two motors. One is the motor for using in room temperature and another is the motor for using very low temperature. This paper designs with Equivalent circuit Method and uses Finite Element Method to analysis. The motor for very low temperature considers variation of coil resistivity due to temperature change and compare torque characteristic with the motor for room temperature. Design element of motor for very low temperature considers resistivity variation following temperature change on going through this paper. The result shows that two types of motors are almost same torque curve characteristic even though they are not the same environment.

• 수산해양기술연구
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• 제27권2호
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• pp.105-119
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• 1991

In order to study the seasonal variation in the physical properites in Suyoung Bay, we investigated the distributions of temperature, salinity, transparency and water color from May 1989 to April 1990. We also observed the tidal currents from February 27 to March 6 1990. There are conspicuous seasonal variation in water temperature and salinity. Water masses are characterized by two water types, i.e., one is influenced principally by river runoff and the other by the Tsushima Current. Transparency and water color increased gradually from the head of the bay to the mouth of the bay in all seasons. In winter, the transparency of water becomes minimum due to the enhanced vertical mixing.