• The KIPS Transactions:PartB
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• v.17B no.5
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• pp.375-380
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• 2010

Most of previous algorithms of object boundary extraction have been studied for extracting the boundary of single object. However, multiple objects are much common in the real image. The proposed algorithm of extracting the boundary of each of multiple objects has two steps. In the first step, we propose the fast method using the outer and inner products; the initial contour including multiple objects is split and connected and each of new contours includes only one object. In the second step, an improved active contour model is studied to extract the boundary of each object included each of contours. Experimental results with various test images have shown that our algorithm produces much better results than the previous algorithms.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.6
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• pp.111-121
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• 2000

Generally, the hydraulic pressures are used for transmitting the force. Therefore, a highly reliable and inexpensive control system has been required for a passenger car. The control-ability of active suspension system is strongly affected by the performance of pressure control valve in the view of dynamic response and energy consumption. In this study, we suggested main design parameters for the optimum design of proportional pressure control valve. The mathematical simulation model was derived from the quarter type model which consisted a valve and hydraulic damper for the purpose of analyzing the valve characteristics. Experiments were performed to confirm the performance of the valve and computations were carried out to ascertain the usefulness of the developed program. The results from computations fairly coincide with those from experiments. This has been achieved by developing the servomechanism valve which comprises the simple combination of a solenoid, a spool valve and a poppet valve. The results from experiments and computations show the development process of optimum proportional pressure control valve in the hydraulics system.

• Applied Biological Chemistry
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• v.21 no.1
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• pp.31-34
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• 1978

The stability of active ingredient of BPMC formulation under ultraviolet lights and sunlights was investigated using dust, emulsifiable concentrate and granular. The active ingredient of BPMC dust was more rapidly degraded by irradiation with ultraviolet lights than emulsifiable concentrate or granular tested. In the case of BPMC emulsions, the degree of degradation was increased in the order of granular, emulsifiable concentrate, dust by irradiation with ultraviolet lights. BPMC was unstable in alkaline solution and ultraviolet lights had highly significant relation to the decomposition of its active ingredient.

• Korean Journal of Remote Sensing
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• v.33 no.1
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• pp.47-60
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• 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.

• BMB Reports
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• v.40 no.6
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• pp.1095-1099
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• 2007

Endonuclease G (EndoG) is a mitochondrial non-specific nuclease that is highly conserved among the eukaryotes. Although the precise role of EndoG in mitochondria is not yet known, the enzyme is released from the mitochondria and digests nuclear DNA during apoptosis in mammalian cells. Schizosaccharomyces pombe has an EndoG homolog Pnu1p (previously named SpNuc1) that is produced as a precursor protein with a mitochondrial targeting sequence. During the sorting into mitochondria the signal sequence is cleaved to yield the functionally active endonuclease. From the analogy to EndoG, active extramitochondrial Pnu1p may trigger cell killing by degrading nuclear DNA. Here, we tested this possibility by expressing a truncated Pnu1p lacking the signal sequence in the extramitochondrial region of pnu1-deleted cells. The truncated Pnu1p was localized in the cytosol and nuclei of yeast cells. And ectopic expression of active Pnu1p led to cell death with fragmentation of nuclear DNA. This suggests that the Pnu1p is possibly involved in a certain type of yeast cell death via DNA fragmentation. Although expression of human Bak in S. pombe was lethal, Pnu1p nuclease is not necessary for hBak-induced cell death.

• Journal of Life Science
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• v.9 no.2
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• pp.44-48
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• 1999

The ionization of tyrosine residue is known to be involved in the stabilization of transition-state in catalysis of astacin based upon the astacin-transition state analog structure. Two tyrosine residues, Tyr-216 and Tyr-219, are conserved in all MMPs related with astacin family, We replaced Tyr-216 and Tyr-219 into phenylalanine, respectively and the zinc binding properties, kinetic parameters, and pH dependence of each mutant are determined in order to examine the role of tyrosine residue in matrilysin catalysis. Both mutants contain two zinc atoms per mol of enzyme, indicating that either tyrosime does not affect the zinc binding property of the enzyme. Y216F and Y219F mutants are highly active and the kcat/Km values are only decreased 1.1-1.5-fold compared to the wild-type enzyme. The decrease in the activity of the mutants is essentially due to the increase in Km value. The pH dependencies of the kcat/Km values for both mutants are similar to the corresponding dependencies obtained with the wild type enzyme. The pKa values at the alkaline side of both mutants are not changed. These kinetic and pH dependence results indicate that the ionization of active site tyrosine residue of matrilysin is not reflected in the kinetics of peptide hydrolysin as catalyzed by astacin.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.15
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• pp.5999-6003
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• 2014

Pesticides used in Korea are grouped by four classes of hazard (extremely, highly, moderately and slightly hazardous) based on acute oral and dermal toxicity in the rat. However, there is little information of carcinogenic effects. The aim of this study was to evaluate potential carcinogenicity for active ingredients of pesticides used in Korea. A total of 1,283 pesticide items were registered under the Pesticide Control Act of which 987 were commercially available. Of these 987 items, 360 active ingredients not duplicated were evaluated for carcinogenicity using the carcinogen list established by the US Environmental Protection Agency (EPA). Some 25 out of 360 ingredients were classified as likely to be carcinogenic (probable) to humans and 52 had suggestive evidence of carcinogenic potential (suspected) based on the US EPA classification. Some 31% of 987 items contained probable or suspected human carcinogenic ingredients. Carcinogenic pesticides accounted for 24% (5,856/24,795 tons) of the total volume of consumption in Korea. Interestingly, pesticides with lower acute toxicity were found to have higher carcinogenic potential. Based on these findings, the study suggests that it is important to provide information on long-term toxicity to farmers, in addition to acute toxicity data.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1458-1463
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• 2003

This paper presents an improved identification algorithm of active magnetic bearing rotor systems considering sensor and actuator dynamics. An AMB rotor system has both real and complex poles so that it is very hard to identify them together. In previous research, a linear transformation through a fictitious proportional feedback was used in order to shift the real poles close to the imaginary axis. However, the identification result highly depends on the fictitious feedback gain, and it is not easy to identify the additional dynamics including sensor and actuators at the same time. First, this paper discusses the necessity and a selection criterion of the fictitious feedback gain. An appropriate feedback gain minimizes dominant SVD(Singular Value Decomposition) error through maximizing rank deficiency. Second, more improvement in the identification is achieved through separating the common additional dynamics in all elements of frequency response matrix. The feasibility of the proposed identification algorithm is proved with two theoretical AMB rotor models. Finally, the proposed scheme is compared with previous identification methods using experimental data, and a great improvement in model quality and large amount of time saving can be achieved with the proposed method.

• Fashion & Textile Research Journal
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• v.4 no.1
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• pp.56-63
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• 2002

This study was designed to investigate the new concept about lifestyle of female consumer in the present time of digital revolution and to analyze the preferences and sensibilities according to the types of consumer lifestyle classified into the same group. Survey was done through questionnaire of 79 questions and the data of 151 female consumers in the age of 19-34 were analyzed statistically using SPSS. The 6 factors were extracted from 39 lifestyle questions: consumerism, seeking challenge, communal life, quality of life, digital orientation and active counter plan. 6 Lifestyle clusters of female consumers were as following: the no-concern satisfied, the digital passive, the consumer personal, the digital active, the consumer communal and the adventurous. 30.5% of female consumer was the digital lifestyle who are relatively older and highly educated, of high income and expense rate, and resident in Gangnam. The preferred sensations by female consumer were 5; reasonal, feminine, conspicuous, active, and modest, and the clusters according to the sensations were 5: the casual, the status-symbolism, the rich in contents, the romantist, and the elegance. Lifestyle and preferred sensations were so related that the no-concern satisfied were the status-symbolism and the romantist, while the digital were the richness of contents and the adventurous were the romantist.

• Journal of Electrochemical Science and Technology
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• v.7 no.4
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• pp.316-326
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• 2016

Development and discovery of efficient, cost-effective, and robust electrocatalysts are imperative for practical and widespread implementation of water electrolysis and fuel cell techniques in the anticipated hydrogen economy. The electrochemical reactions involved in water electrolysis, i.e., hydrogen and oxygen evolution reactions, are complex inner-sphere reactions with slow multi-electron transfer kinetics. To develop active electrocatalysts for water electrolysis, the physicochemical properties of the electrode surfaces in electrolyte solutions should be investigated and understood in detail. When electrocatalysis is conducted using nanoparticles with large surface areas and active surface states, analytical techniques with sub-nanometer resolution are required, along with material development. Scanning electrochemical microscopy (SECM) is an electrochemical technique for studying the surface reactions and properties of various types of electrodes using a very small tip electrode. Recently, the morphological and chemical characteristics of single nanoparticles and bio-enzymes for catalytic reactions were studied with nanometer resolution by combining SECM with atomic force microscopy (AFM). Herein, SECM techniques are briefly reviewed, including the AFM-SECM technique, to facilitate further development and discovery of highly active, cost-effective, and robust electrode materials for efficient electrolysis and photolysis.