• Title/Summary/Keyword: synthetic observations

Search Result 92, Processing Time 0.019 seconds

An Outlier Data Analysis using Support Vector Regression (Support Vector Regression을 이용한 이상치 데이터분석)

  • Jun, Sung-Hae
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.18 no.6
    • /
    • pp.876-880
    • /
    • 2008
  • Outliers are the observations which are very larger or smaller than most observations in the given data set. These are shown by some sources. The result of the analysis with outliers may be depended on them. In general, we do data analysis after removing outliers. But, in data mining applications such as fraud detection and intrusion detection, outliers are included in training data because they have crucial information. In regression models, simple and multiple regression models need to eliminate outliers from given training data by standadized and studentized residuals to construct good model. In this paper, we use support vector regression(SVR) based on statistical teaming theory to analyze data with outliers in regression. We verify the improved performance of our work by the experiment using synthetic data sets.

Derivation of the Synthetic Unit Hydrograph at Ungaged Small Watershed (미계측 소하천수계의 합성단위도 유도)

  • 안상진;이억한
    • Water for future
    • /
    • v.19 no.2
    • /
    • pp.157-166
    • /
    • 1986
  • The objective of this study was to determine the best representative synthetic unit hydrograph that is applicable to ungaged small watershed. A typical unit hydrograph was established with the actual data from a small watershed. Four currently well-known methods for analyzing ungaged small watershed, including Snyder's, Clark's S.C.S. and Nash methods, were evaluated with the data from the same small watershed. The following observations were noted from the analysis of four methods. The Snyder's method yielded the similar peak discharge value as the typical unit hydrograph. With co-ordinates of three discharge values, i.e. 25%, 50% and 75% of peak discharge, were not adequate for deriving a typical unit hydrograph in ungaged small watershed. With Clark's method there shall be some way of obtaining the exact base length of time area diagram and isochrone of each reach of the stream. With Nash method peak discharge and base flow time are affected by the storage constant and gamma function argument; therefore, for deriving a more reliable and workable unit hydrograph one needs to select for the better estimation of storage constant and gamma function argument. In S.C.S. method peak discharge is directly related to the watershed area and inversely related to the time of peak diacharge. Therefore area with faster peak discharge yielded the higer peak discharge value. Although the peak discharge value obtained frome the S.C.S. method higher than the value obtained from the unit hydrograph developed from the actual data, this method contains a number of advantageous factors. The peak discharge value and the time of peak discharge can be claculated easity from the morphological characteristics of the watershed, and in S.C.S method co-ordinates of the unit hydrograph can be calculated easily from that of the dimensionless unit hydrograph. When the four currently used methods were evaluated with a typical unit hydrograph obtained from the actual data, the S.C.S method was show to be the best method in deriving a synthetic unit hydrograph for ungaged small watershed.

  • PDF

Classification for landfast sea ice types in Greenland with texture analysis images (텍스쳐 이미지를 이용한 그린란드 정착빙의 분류)

  • Hwang, Do-Hyun;Hwang, Byong-Jun;Yoon, Hong-Joo
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.8 no.4
    • /
    • pp.589-593
    • /
    • 2013
  • Remote sensing of SAR images is suitable for sea ice observations to obtain the sea ice data if clouds or weather conditions change. There are various types of sea ice, classification results can be seen more easily to detect the change by types of sea ice. In this study, we classified the image by supervised classification method, which is minimum distance was used. Also, we compared the overall accuracy when compared to the results with classification result of SAR images and the result of texture images. When using Radarsat-2 texture images, the overall accuracy was the highest, generally, when using the SAR images had higher overall accuracy.

Ribonucleic Acid and Ribonuclease Activity in the Developing Shoot of Rice Plants at Low Temperature (벼의 유아기(刻芽期)에 냉해(冷害)가 RNA 및 RNase 활성도(活性度)에 미치는 영향(影響))

  • Kim, In-Soo;Lee, Chun-Yung
    • Applied Biological Chemistry
    • /
    • v.15 no.3
    • /
    • pp.187-192
    • /
    • 1972
  • The qualitative and quantitative changes in RNA in terms of RNase activity of rice plants subjected to the chilling temperature were studied. The total RNA level increased at the early stage and thereafter decreased continuously while the progress of the chilling injury. The change of total RNA was mainly dependent upon the change of ribosomal RNA with soluble RNA less changed. Parallelism between total RNA level and RNase activity was observed at the early stage of chilling injury, while the inverse relationship of RNA RNase was seen in the later stage. Our observations indicate that synthetic function of RNase may be more closely related to ribosomal RNA than soluble RNA.

  • PDF

On the Spatial and Temporal Variability of L-band Polarimetric SAR Observations of Permafrost Environment in Central Yakutia

  • Park, Sang-Eun
    • Korean Journal of Remote Sensing
    • /
    • v.33 no.1
    • /
    • pp.47-60
    • /
    • 2017
  • The permafrost active layer plays an important role in permafrost dynamics. Ecological patterns, processes, and water and ice contents in the active layer are spatially and temporally complex depending on landscape heterogeneity and local-scale variations in hydrological processes. Although there has been emerging interest in the application of optical remote sensing techniques to permafrost environments, optical sensors are significantly limited in accessing information on near surface geo-cryological conditions. The primary objective of this study was to investigate capability of L-band SAR data for monitoring spatio-temporal variability of permafrost ecosystems and underlying soil conditions. This study exploits information from different polarimetric SAR observables in relation to permafrost environmental conditions. Experimental results show that each polarimetric radar observable conveys different information on permafrost environments. In the case of the dual-pol mode, the radar observables consist of two backscattering powers and one correlation coefficient between polarimetric channels. Among them, the dual-pol scattering powers are highly sensitive to freeze/thaw transition and can discriminate grasslands or ponds in thermokarst area from other permafrost ecosystems. However, it is difficult to identify the ground conditions with dual-pol observables. Additional backscattering powers and correlation coefficients obtained from quad-pol mode help understanding seasonal variations ofradar scattering and assessing geo-cryological information on soil layers. In particular, co-pol coherences atHV-basis and circular-basis were found to be very usefultools for mapping and monitoring near surface soil properties.

Antimicrobial Peptides (AMPs): Peptide Structure and Mode of Action

  • Park, Yoon-Kyung;Hahm, Kyung-Soo
    • BMB Reports
    • /
    • v.38 no.5
    • /
    • pp.507-516
    • /
    • 2005
  • Antimicrobial peptides (AMPs) have been isolated and characterized from tissues and organisms representing virtually every kingdom and phylum. Their amino acid composition, amphipathicity, cationic charge, and size allow them to attach to and insert into membrane bilayers to form pores by 'barrel-stave', 'carpet' or 'toroidal-pore' mechanisms. Although these models are helpful for defining mechanisms of AMP activity, their relevance to resolving how peptides damage and kill microorganisms still needs to be clarified. Moreover, many AMPs employ sophisticated and dynamic mechanisms of action to carry out their likely roles in antimicrobial host defense. Recently, it has been speculated that transmembrane pore formation is not the only mechanism of microbial killing by AMPs. In fact, several observations suggest that translocated AMPs can alter cytoplasmic membrane septum formation, reduce cell-wall, nucleic acid, and protein synthesis, and inhibit enzymatic activity. In this review, we present the structures of several AMPs as well as models of how AMPs induce pore formation. AMPs have received special attention as a possible alternative way to combat antibiotic-resistant bacterial strains. It may be possible to design synthetic AMPs with enhanced activity for microbial cells, especially those with antibiotic resistance, as well as synergistic effects with conventional antibiotic agents that lack cytotoxic or hemolytic activity.

A Study on the Clothing Culture for New Generation of Korea and Japan (2002 한.일 국민교류년 기념' 한국과 일본의 신세대의 복식업화에 대한 연구 - Street Fashion을 중심으로 -)

  • 백샘이;간호섭
    • Journal of the Korean Society of Costume
    • /
    • v.53 no.3
    • /
    • pp.31-49
    • /
    • 2003
  • The Purpose of this research is to examine and contrast the cultural characteristics of the street fashion in new generations of Korea and Japan. We also intended to help clothing companies understand the current trend in this new generation. As the method for street fashion analysis. various literature, internet information and new media materials were utilized. Key observations obtained are as following First, they pursue a complex image. New generations seem to admix images from different areas to create a synthetic image, rather than adopting a single image; Second, practicality is an important factor. They Pursue a sense of their own unique trend: Third, distinction. The difference in society values between Koreans and Japanese is incorporated. The Korean new generation considers the traditional moral principles as important social values. In contrast the Japanese new generation is greatly influenced by the open sexuality culture ; Fourth. public ownership and sharing of the culture. There is a gradual deviation from a dominating unidirectional influence from one country on another. Now the two countries are influencing each other ; Fifth, sense. There are numerous fashion items and generalized total coordination. New generations express more active and creative fashion sense in those fashion items.

Retrieval of surface parameters in tidal flats using radar backscattering model and multi-frequency SAR data

  • Choe, Byung-Hun;Kim, Duk-Jin
    • Korean Journal of Remote Sensing
    • /
    • v.27 no.3
    • /
    • pp.225-234
    • /
    • 2011
  • This study proposes an inversion algorithm to extract the surface parameters, such as surface roughness and soil moisture contents, using multi-frequency SAR data. The study areas include the tidal flats of Jebu Island and the reclaimed lands of Hwaong district on the western coasts of the Korean peninsula. SAR data of three frequencies were accordingly calibrated to provide precise backscattering coefficients through absolute radiometric calibration. The root mean square (RMS) height and the correlation length, which can describe the surface roughness, were extracted from the backscattering coefficients using the inversion of the Integral Equation Method (IEM). The IEM model was appropriately modified to accommodate the environmental conditions of tidal flats. Volumetric soil moisture was also simultaneously extracted from the dielectric constant using the empirical model, which define the relations between volumetric soil moistures and dielectric constants. The results obtained from the proposed algorithm were verified with the in-situ measurements, and we confirmed that multi-frequency SAR observations combined with the surface scattering model for tidal flats can be used to quantitatively retrieve the geophysical surface parameters in tidal flats.

GPS-Based Orbit Determination for KOMPSAT-5 Satellite

  • Hwang, Yoo-La;Lee, Byoung-Sun;Kim, Young-Rok;Roh, Kyoung-Min;Jung, Ok-Chul;Kim, Hae-Dong
    • ETRI Journal
    • /
    • v.33 no.4
    • /
    • pp.487-496
    • /
    • 2011
  • Korea Multi-Purpose Satellite-5 (KOMPSAT-5) is the first satellite in Korea that provides 1 m resolution synthetic aperture radar (SAR) images. Precise orbit determination (POD) using a dual-frequency IGOR receiver data is performed to conduct high-resolution SAR images. We suggest orbit determination strategies based on a differential GPS technique. Double-differenced phase observations are sampled every 30 seconds. A dynamic model approach using an estimation of general empirical acceleration every 6 minutes through a batch least-squares estimator is applied. The orbit accuracy is validated using real data from GRACE and KOMPSAT-2 as well as simulated KOMPSAT-5 data. The POD results using GRACE satellite are adjusted through satellite laser ranging data and compared with publicly available reference orbit data. Operational orbit determination satisfies 5 m root sum square (RSS) in one sigma, and POD meets the orbit accuracy requirements of less than 20 cm and 0.003 cm/s RSS in position and velocity, respectively.

Effect of Permethrin on Embryonic Developments in Rats (랫드에 미치는 Permethrin의 발생독성에 관한 연구)

  • Yoon, Hyo-Jung;Chung, Moon-Ho
    • Journal of Environmental Health Sciences
    • /
    • v.31 no.4 s.85
    • /
    • pp.254-259
    • /
    • 2005
  • Permethrin, a synthetic pyrethroid insecticide, has been widely used to protect domestic animals and the public health, as well as in agriculture against a variety of pests, which provides potential for environmental exposure. Permethrin is classified as possible human carcinogen and endocrine disrupting chemical by many international authorities. However, its developmental effects have been rarely studied. This study investigated the effects of permethrin during embryo-genesis. Developmental toxicity of permethrin was evaluated using short-term in vitro battery system. Gestation day 9.5 rat embryos (organogenesis) were cultured with permethrin (0.1,0.4 and 0.8 mg/ml) for 48 hours using whole embryo culture system. All the treatments exhibited significant decreases in the total morphological score. Permethrin induced significant growth retardation and the developmental abnormality at doses of 0.4 and 0.8 mg/ml. Moreover, the DNA and protein contents of embryos decreased in dose-dependent manner. These observations suggest that permethrin contributes to toxicity on embryonic developments in rats.