• Proceedings of the KOSOMBE Conference
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• v.1993 no.05
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• pp.38-41
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• 1993

For efficient transmission and storage of digital images, the requirements of image compression is incresing. Because the medical images contain diagnostic information small distortion has been more important factor than the low rate in such images. Generally the distortion in image is the difference of pixel values. However the image is percieved by human visual systems. So it is reasonable that human visual system characteristics be used as criteria of the image compression. In this paper, the Just Noticeable Difference curve is used as criteria of determining the homogeniety of a block and acceptibility of distortions. And Block Truncation Coding using spatial masking effect of eyes is adopted to code the blocks which contain line components. And small blocks which varies slowly can be approximated to polynomial functions successfully. We proposed the hybrid block coding scheme based on the block characteristics and human visual system characteristics. Simulation to several kinds of the medical images using this method showed that medical images can be compressed 5:1 - 10:1 without noticeable distortion.

• Journal of the Korean Society of Systems Engineering
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• v.1 no.2
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• pp.26-33
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• 2005

In this paper, an algorithm is presented to recognize road based on unpaved test courses image. The road images obtained by a video camera undergoes a pre-processing that includes filtering, gray level slicing, masking and identification of unpaved test courses. After this pre-processing, a part of image is grouped into 27 sub-windows and fed into a three-layer feed-forward neural network. The neural network is trained to indicate the road direction. The proposed algorithm has been tested with the images different from the training images, and demonstrated its efficacy for recognizing unpaved road. Based on the test results, it can be said that the algorithm successfully combines the traditional image processing and the neural network principles towards a simpler and more efficient driver warning or assistance system.

• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.29.4-30
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• 2009

Extra-tidal feature of the globular clusters such as tidal tails and halos can be a crucial evidence of the merging scenario of the Galaxy formation in the dynamical point of view. To search for such an extra-tidal feature of globular clusters located in the Galactic bulge(RGC<3kpc), we obtained wide-field near-infrared JHKs images of 6 metal-poor ([Fe/H]<-1.0) clusters and 3 metal-rich ([Fe/H]>-1.0) clusters. Observations were carried out using IRSF 1.4m telescope and SIRIUS near-infrared camera, during 2006~2007. The obtained images have a total maximum field-of-view of ~ $21'\times 21'$. To select clusters' member stars and minimize the field star contaminations, we applied CMD masking algorithm. Smoothed surface density contour maps with selected stars for each cluster show overdensity features around the tidal radius and beyond. Also, radial surface density profiles within the tidal radius of the clusters show an overdensity feature as a change of slope of the radial profile. The results add further observational constraints of the formation of the Galactic bulge.

• Preventive Nutrition and Food Science
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• v.12 no.4
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• pp.222-228
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• 2007

This study was conducted to investigate the minimization of off-flavor occurrence and the maintenance of high quality in modified atmosphere packaged Pleurotus ostreatus during the storage. There are 4 treatments used to preserve high quality and for deodorization of MAP mushroom: Artemisia princeps, Artemisia capillaries, green tea and activated charcoal. The mushrooms were packed in polyethylene film with each treatment and were stored at 5 and $20^{circ}C$. No difference was observed in weight loss, $CO_2\;and\;O_2$ concentration, or color of mushrooms packed with or without treatment. However, the principal component analysis (PCA), electronic nose, revealed differences in off-flavor occurrence between control (MAP mushroom without treatment) and treatment groups at $5^{\circ}C$. This result suggested that Artemisia princeps and Artemisia capillaries was masking the off-flavor in MAP mushroom because the unique flavor of them was strongly revealed and green tea and activated charcoal might have a role of removing the off-flavor by adsorbing ethanol and acetaldehyde, which is known to cause off-flavor. The sensory test showed that Artemisia princeps and Artemisia capillaries dough treatment inhibited microbial growth.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.6
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• pp.888-895
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• 2010

Riceyeotgangjung (RYG) with added spirulina was prepared with citron juice for masking of odor. Oil temperature for puffing was found to be $220^{\circ}C$ for frying dry rice based upon the results of expansion rate and color. RYGs with added spirulina (1, 2, and 3%) were prepared under the above conditions, and their physicochemical and sensory properties were examined under storage at $60^{\circ}C$ for 15 days. Moisture content of RYG decreased proportionally with the spirulina content and storage time. The hardness levels of the freshly made RYGs with spirulina were higher than that of control. During storage, the hardness of the control gradually increased, but those of the RYGs with spirulina gradually decreased, although no significant differences existed between the spirulina containing RYGs. Lightness and redness values in the Hunter color system decreased according to the spirulina content and storage time. Yellowness value also increased with the spirulina content and storage time. Phycocyanin and total phenolic content increased with spirulina content, but decreased with the storage period. Sensory evaluation results showed that RYG with 2% added spirulina received the highest scores for color, taste, overall acceptability, and intention of purchase. As a result, the optimal addition amount of spirulina to RYG is recommended to be 2%.

• Bulletin of the Korean Chemical Society
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• v.25 no.8
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• pp.1137-1142
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• 2004

A spectrophotometric and first derivative spectrophotometric method was developed in aquatic Tween 80 micellar solutions for selective determination of nickel without using any pre-separation step. 1-(2-Pyridylazo)-2-naphthol (PAN), as a sensitive chromogenic complexing agent formed a red-colored Ni(II)-PAN complex in Tween 80 media with satisfactory solubility and stability. Conditions such as pH, PAN concentration, type and concentration of micellizing agent were optimized. Molar absorptivity of Ni-PAN complex was found $4.62\;{\times}\;10^4L\;cm^{?1}\;mol^{?1}$ at 569 nm, under the optimum condition. Calibration graphs were derived by zero, first and second derivative spectrophotometry at maximum wavelengths of 569, 578 and 571 nm with linear ranges of 30-1800, 20-2500 and 30-2000 ng $mL^{?1}$ , respectively. Precision as standard deviation as well as accuracy as recovery percent were in the range of 1-20 ng $mL^{?1}$, and 93.3-103.3%, respectively, for the entire of the linear ranges. Spectrophotometric detection limit was 3 ng $mL^{?1}$ and effects of diverse ions on the first derivative determination of nickel were studied to investigate selectivity of the method. Interferences of cobalt and copper on the nickel determination were prevented using o-phenanthroline as masking agent. The recommended procedures were applied to the various synthetic and stainless steel alloys, tea leaves and human hair, with satisfactory results.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.34.2-34.2
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• 2016

X-ray cavities are typically detected as surface brightness depression in X-ray diffuse emission from hot gas in high resolution X-ray images (i.e., Chandra and XMM-Newton). Showing the coincidence of location with radio jets, X-ray cavities imply that the radio jets interact with interstellar/intergalactic medium. It is important to understand them since they can be a clue of understanding AGN feedback to their host galaxies. To understand the physics of the AGN feedback, X-ray cavity has been actively studied while there are only a few statistical studies on X-ray cavity based on small or incomplete samples. Hence, a systematic study with a large sample is needed. With the condition of sufficient X-ray photons to detect surface brightness depression, we constructed a large sample of 133 galaxy clusters, galaxy groups, and individual galaxies to investigate X-ray cavities. We detected 201 cavities from 94 objects using two detection methods (i.e., beta-modeling and unsharp masking method), and confirmed the cavity size-distance relation over a large dynamical range. The size-distance relation does not vary for different environments (i.e., galaxy cluster, groups, and individual galaxies), suggesting that there is little environmental effect on the formation of X-ray cavity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.2
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• pp.275-280
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• 1998

The possibility of utilizing Porphyra yezoensis, Undaria pinnatifida and Laminaria religionsa into algae-tea having biological functionality was investigated by analysis of functional component, experimentation for low viscosity and various pretreatments. In water soluble fraction of powdered algae extracted for 3 minutes with 30 times of hot wate, major functinal components were composed of 1.53% porphyran and 170.04mg% taurine in P. yezoensis, 1.09% fucoidan and 1.18% sodium sodium alginate in U. pinnatifida, and 1.28% fucoidan, 1.99% soidum laginate and 371.25mg% iodine in L.religiosa, on dry basis. For lowering viscosity and masking off-flavor in each water soluble fraction, it was desirable that P. yezoensis was washed for 12 hours in sea water and 30 mimutes in fresh water, dried at 3 to 5$^{\circ}C$, powdered to size of 30 mesh nd then roasted for 3 minutes at 12$0^{\circ}C$, and that both U. pinnatifida and L. religiosa were washed, semidried to 40~50% moisture content, heated for 40 minutes at 12$0^{\circ}C$ by autoclave, dried, powdered to size of 30 mesh and then roasted for 5 minutes at 11$0^{\circ}C$.

• Korean Journal of Biological Psychiatry
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• v.3 no.1
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• pp.30-36
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• 1996

Tardive dyskinesia is a syndrome of involuntary hyperkinetic abnormal movements that occurs during or shortly after the cessation of neuroleptic drug treatment. Typically, the movements are choreoatheoid. Other movements such as tics and dystonia may be present. Nonetheless, any dyskinesia seen in a neuroleptic-treated patient is not always neuroleptic-induced tardive dyskinesia. The prevalence of tardive dyskinesia varies widely, which reflects many methodological problems, such as differential diagnosis. symptom fluctuation, masking effect of neuroleptics, validated diagnostic criteria. Of suggested risk factors, only old age has been consistently found to be associated with an increased frequency of tardive dyskinesia. Many hypotheses about the pathophysiolgy of tardive kinesia are proposeed, but time-honored ones are not present. No consistently safe and effective treatments are found. Various treatment modalities signifies the general ineffectiveness of these agents for most patients. In general, reduction or cessation of neuroleptics, if possible, is recommended. Remission or improvemets of tardive dyskinesia after neuroleptics withdrawal usually occurs among most patients within three months.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.1
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• pp.9-17
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• 2014

Electrical compound action potential (ECAP) can be recorded on cochlear implant. This study will investigate stimulation and recording to enhance the efficacy of ECAP. 34 articles was used. We analyzed pulse and stimulating condition, artifact suppression, recording condition. The cathod-leading biphasic pulse was used with as short as possible pulse width and inter phase gap for the efficacy of neural firing, stable threshold and preventing neural degeneration. Around C-level was stimulated to apical, middle and basal turn of cochlea. Artifact was eliminated by forward-masking, template-subtraction technique. For clearer waveform, we need to change distance between stimulating and recording electrode, the gain of amplification, number of average.