• Korean Journal of Weed Science
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• v.12 no.4
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• pp.368-373
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• 1992

The effect of alachlor treatment on protein synthesis was studied. Protein synthesis was inhibited by $1{\times}10^{-4}$ M and $1{\times}10^{-3}$M of alachlor 5.8% and 86.5%, respectively, while did not occur blow $1{\times}10^{-5}$M alachlor. Soluble protein of alachlor treated oat root tips was examined by polyacrylamide gel electrophoresis. The proteins extracted from oat root tips showed that they were made up of subunits blow 100 kd polypeptides by SDS-PAGE. As compared to control, high molecular proteins(above 47 kd) were inhibited of oat root treated with alachlor, while low molecular proteins(below 23 kd) were increased. Two-D gels showed that alachlor caused decrease(1-6 spots) or increase(7-10 spots) in number of polypeptides on silver staining. The intensity of some polypeptides of soluble proteins (molecular mass of 83 kd : 1, 2 spots, 70 kd : 3, 4 spots, and 47.5 kd : 5, 6 spots) decreased in alachlor treatment, whereas the intensity of other peptide bands (20 kd : 7 spot and 16 kd : 8, 9, 10 spots) increased. Oat root tip proteins present in the neutral zone are masked by diffusing of major proteins, but proteins in acid zone are resolved minor proteins.

• Journal of Ecology and Environment
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• v.45 no.4
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• pp.277-286
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• 2021

Background: As trade increases, the influx of various alien species and their spread to new regions are prevalent and no longer a special problem. Anthropogenic activities and climate changes have made the distribution of alien species out of their native range common. As a result, alien species can be easily found anywhere, and they have nothing but only a few differences in intensity. The prevalent distribution of alien species adversely affects the ecosystem, and a strategic management plan must be established to control them effectively. To this end, hot spots and cold spots were analyzed according to the degree of distribution of invasive alien plants, and major environmental factors related to hot spots were found. We analyzed the 10,287 distribution points of 126 species of alien plants collected through the national survey of alien species by the hierarchical model of species communities (HMSC) framework. Results: The explanatory and fourfold cross-validation predictive power of the model were 0.91 and 0.75 as AUC values, respectively. The hot spots of invasive plants were found in the Seoul metropolitan area, Daegu metropolitan city, Chungcheongbuk-do Province, southwest shore, and Jeju island. Generally, the hot spots were found where the higher maximum temperature of summer, precipitation of winter, and road density are observed, but temperature seasonality, annual temperature range, precipitation of the summer, and distance to river and sea were negatively related to the hot spots. According to the model, the functional traits accounted for 55% of the variance explained by the environmental factors. The species with higher specific leaf areas were more found where temperature seasonality was low. Taller species preferred the bigger annual temperature range. The heavier seed mass was only preferred when the max temperature of summer exceeded 29 ℃. Conclusions: In this study, hot spots were places where 2.1 times more alien plants were distributed on average than non-hot spots (33.5 vs 15.7 species). The hot spots of invasive plants were expected to appear in less stressful climate conditions, such as low fluctuation of temperature and precipitation. Also, the disturbance by anthropogenic factors or water flow had positive influences on the hot spots. These results were consistent with the previous reports about the ruderal or competitive strategies of invasive plants instead of the stress-tolerant strategy. The functional traits are closely related to the ecological strategies of plants by shaping the response of species to various environmental filters, and our result confirmed this. Therefore, in order to effectively control alien plants, it is judged that the occurrence of disturbed sites in which alien plants can grow in large quantities is minimized, and the river management of waterfronts is required.

• Journal of Biosystems Engineering
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• v.19 no.3
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• pp.232-246
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• 1994

This study was conducted to develop the long-tenn storage method to minimize the black spot occurred on the surface of persimmons stored in the films at low temperature. The storage experiments were done with different films and persimmon varieties at $0^{\circ}C$ storage condition for 5 months, and then the physical and chemical characteristics of persimmons were tested monthly. The results were as follows : 1. The film 160 made from zeolites showed highest performance in well storings sweet persimmons for 5 months, compared with other films by eyesight. The initial moisture condensation inside the films seemed to cause the black spots on persimmons, and the effect of the film holes was never significant to prevent the black spots. 2. The sugar content was ranged from $14^{\circ}Brix$ to $15^{\circ}Brix$ regardless of film types and persimmom varieties, and it changed little for storage of 5 months. 3. The decrease rate of persimmom weight in the film 160 and 180 was 0.3% for storage of 5 months, while those in other films reached to 2%. The decrease rate of persimmon weight was least in the film 160 and 180. 4. The hardness of Fuyu least decreased in the films 160 and 380. It was changed from 36 kg/cnf to 8-27 $kg/cm^2$, and that of Charyang was from 31 $kg/cm^2$ to 8-10 $kg/cm^2$ for storage of 5 months. The hardness of Charyang rapidly decreased as storage period increased. 5. The average rate of black spot(defect rate) of Fuyu measured by a computer image processing system was least in the film 160 by 0.5%, but those in other films was ranged from about 5% to 20% for storage of 5 months. The rate of black spot of Charyang was less than that of Fuyu among most of films. 6. The intensity, hue, and saturation in persimmon color changed according to storage period. Especially, the intensity of persimmon colors decreased as storage period increased, but it was least in the film 160. 7. An integrated long-term storage method of sweet persimmons was suggested in the basis of the experiments and literature reviews.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.6
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• pp.640-647
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• 2001

In this paper, a noise-tolerant generalized symmetry transform(NTGST) is proposed as an effective attention operator for the spot detection in BLU inspection, in which various spots with variable sizes, shapes, gray levels, and low contrast, should be detected from the complex, noisy background with lattice shaped shading. The proposed NTGST takes into account the polarity of convergence and divergence of the radial orientation of the intensity gradient as well as it's magnitude and symmetry, and thereby can detect only the BLU spots from the noisy and lattice shaped shadows of background. Experiments are conducted on the BLU inspection image obtained by CCD camera, and the proposed NTGST is Proved to be effectively used in BLU inspection.

• Journal of Korean Neurosurgical Society
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• v.66 no.2
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• pp.172-182
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• 2023

Objective : The blood-brain barrier (BBB) is an obstacle for molecules to pass through from blood to the brain. Focused ultrasound is a new method which temporarily opens the BBB, which makes pharmaceutical delivery or removal of neurodegenerative proteins possible. This study was demonstrated to review our BBB opening procedure with magnetic resonance guided images and find specific patterns in the BBB opening. Methods : In this study, we reviewed the procedures and results of two clinical studies on BBB opening using focused ultrasound regarding its safety and clinical efficacy. Magnetic resonance images were also reviewed to discover any specific findings. Results : Two clinical trials showed clinical benefits. All clinical trials demonstrated safe BBB opening, with no specific side effects. Magnetic resonance imaging showed temporary T1 contrast enhancement in the sonication area, verifying the BBB opening. Several low-signal intensity spots were observed in the T2 susceptibility-weighted angiography images, which were also reversible and temporary. Although these spots can be considered as microbleeding, evidence suggests these are not ordinary microbleeding but an indicator for adequate BBB opening. Conclusion : Magnetic resonance images proved safe and efficient BBB opening in humans, using focused ultrasound.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.505-505
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• 2000

Perkinsus sp. has been identified as responsible organism for the decrease in Manil clam production along the west and south coast of Korea. Monthly investigation on infection intensity and pathology of Perkinsus infected Manila clam population was carried out in Komsoe Bay located in the west coast during February and December 1999. About one hundred clams were collected each month for the analysis. Infected clams were incubated in fluid thioglycollate media over a week, stained with iodine solution, digested with 2M NaOH and the number of Perkinsus present in an individual recorded. Histological slides were also prepared from infected clams and their pathologic symptoms were examined using a microscope. Trophozoites of Perkinsus sp. were dominantly distributed on gills and epithelia of digestive glands however a few numbers could be detected at siphons and foot tissues. Heavily infected clams often exhibited white spots on mantle and foot tissues due to the inflammatory reaction of the hemocytes, forming nodules. Trophozoites were also found along the connective tissues of follicles during spawning season indicating that Perkinsus sp. may disturb reproduction of the clam. Total number of Perkinsus sp. in an individual clam varied from none to 9, 550, 000 with a monthly mean of 279, 663 to 2, 198, 558 during the course of study. The number of Perkinsus sp. in the clam was found to lowest durin July and August when unusually low salinity was recorded in this area due to the heavy rain. Highest monthly infection intensity in terms of total number of Perkinsus sp. i clam was observed in February, when water temperature recorded as lowest during the study. Small size of clams with shell length of ten mm or less were not infected with Perkinsus sp. It was concluded that Perkinsus infection in Manila clam is in pa controlled by changes in salinity and clam growth; low salinity environment minimize infection intensity while tile clams get more Perkinsus as they grow.

• BMB Reports
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• v.36 no.6
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• pp.558-564
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• 2003

In microarray data mining, one of the key problems is how to handle weak signals. Based on a bent piecewise linear accumulated distribution generally found in the microarray data, a new detectable threshold finding method is proposed to filter genes with unreliable information in this paper. More reliable and reproducible data is produced for the subsequent data mining.

• The Korean Journal of Applied Statistics
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• v.24 no.5
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• pp.847-859
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• 2011

cDNA microarray-based comparative genomic hybridization(CGH) data includes low-intensity spots and thus a statistical strategy is needed to detect subtle differences between different cancer classes. In this study, genes displaying a high frequency of alteration in one of the different classes were selected among the pre-selected genes that show relatively large variations between genes compared to total variations. Utilizing copy-number changes of the selected genes, this study suggests a statistical approach to predict patients' classes with increased performance by pre-classifying patients with similar genetic alteration scores. Two-stage logistic regression model(TLRM) was suggested to pre-classify homogeneous patients and predict patients' classes for cancer prediction; a decision tree(DT) was combined with logistic regression on the set of informative genes. TLRM was constructed in cDNA microarray-based CGH data from the Cancer Metastasis Research Center(CMRC) at Yonsei University; it predicted the patients' clinical diagnoses with perfect matches (except for one patient among the high-risk and low-risk classified patients where the performance of predictions is critical due to the high sensitivity and specificity requirements for clinical treatments. Accuracy validated by leave-one-out cross-validation(LOOCV) was 83.3% while other classification methods of CART and DT performed as comparisons showed worse performances than TLRM.

• Publications of The Korean Astronomical Society
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• v.15 no.spc1
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• pp.93-102
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• 2000

We have reviewed the magnetic activity in close binaries. Solar like magnetic activity indicators such as photometric spots, chromo spheric emission, coronal X-ray and radio emission, and flare activity are commonplace in many cool stars with convective envelopes. Using the UV spectra we confirmed the strength of stellar activity increases with more rapid rotation and later spectral types which corresponds to the increasing depth of the star's convective envelope. Apart from very young stellar objects such as T Tauri stars, the stars with the highest levels of activity are close binary systems composed of cool stars, i.e., the chromospherically active binaries such as RS CVn, BY Dra, W UMa and related systems. The IUE low and high dispersion spectra of V711 Tau, VW Cep and SW Lac are used for ultraviolet photometry and for a variation study of chromospheric activity. Evidence of chromospherically activity is indicated by the intensity variation of the Mg II emission line with orbital phase.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.514-515
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• 2021

This paper presents a method to find a target using UAVs in LoRa communication environment. The proposed method proposes a UAV flight path so that the target signal can be found without blind spots. The flight path was changed by using the intensity of the transmitted signal during the flight using the variation of the signal strength. We verified the proposed method by simulation and confirmed that it takes a long time to track the target, although the efficiency of the 3 flights is high. It is best to fly three UAVs to reduce time to find target and increase efficiency when the time is a critical factor. The LoRa communication lowers the production cost and makes it possible to construct the system at low cost.