• Bulletin of the Korean Chemical Society
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• v.9 no.1
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• pp.5-9
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• 1988

Pattern recognition techniques have been applied for the extraction of some regularities of water samples under a wide variety of locations related to Han-River. For that purpose, an eigenvector analysis has been applied for defining each class so as to use the class as a training set for class analogy model of SIMCA. The models thus obtained have been used for the allocation of test samples between groups.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.323-331
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• 2024

The concept of 'Han' is a psychological characteristic formed by Koreans through long-lasting national hardships. It has deeply influenced every Korean as a form of collective unconscious and has merged with various forms of art over time. Director Bong Joon-ho's works, rich in social consciousness, symbolically visualize sensitive issues like social class, presenting harsh satire on class oppression. His movies continuously emphasize human desires, the homogeneity of good and evil, insurmountable class barriers, and moral decay caused by desires. They produce a wealth of symbols filled with layers and power dynamics. Bong Joon-ho dramatically portrays and directs various forms of symbols. The metaphorical symbols in his movies provide a unique research value for delving into the deeper meanings of the films.This study examines the theme of 'class Han' in six of Bong Joon-ho's films, exploring the 'Han culture' of Korea. It applies semiotic concepts by categorizing into character and non-character symbols for an in-depth analysis of the films. The representative works from the late 1990s to the late 2010s articulate the class layers of the 'visible' and the 'invisible' through a blend of realism and surrealism. The study analyzes Bong Joon-ho's films in the sequence of 'satire-exposure-hope', examining the culturally critical nature of 'Han culture' on class and its psychological and cultural impact on the general public.

• Journal of Species Research
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• v.7 no.3
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• pp.193-201
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• 2018

Culturable bacterial diversity was investigated using freshwater and sediment samples collected from the North Han River basin in 2017, as a part of the research program 'Survey of freshwater organisms and specimen collection'. Over a thousand bacterial strains were isolated from the samples and identified based on 16S rRNA gene sequences. Among the bacterial isolates, 22 strains showing higher than 98.7% sequence similarity with validly published bacterial species, but not reported in Korea, were classified as unrecorded species in Korea. The 22 bacterial strains were phylogenetically diverse and assigned to 6 classes, 11 orders, 15 families, and 21 different genera. At the generic level, the unreported species were affiliated with Flavobacterium of the class Flavobacteria, Flexibacter of the class Cytophagia, Blastomonas, Brevundimonas, Elstera, Rhizobium, Roseomonas, Sphingomonas, and Xanthobacter of the class Alphaproteobacteria, Albidiferax, Cupriavidus, Curvibacter, Ferribacterium, Hydrogenophaga, Iodobacter, Limnohabitans, Polaromonas, Undibacterium, and Variovorax of the class Betaproteobacteria, Pseudomonas of the class Gammaproteobacteria, and Arcobacter of the class Epsilonproteobacteria. The unreported bacterial species were further characterized by examining Gram reaction, colonial and cellular morphology, and biochemical properties. The detailed descriptions of 22 strains of the unreported bacterial species are also provided.

• Bulletin of the Korean Mathematical Society
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• v.38 no.1
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• pp.163-174
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• 2001

In this paper we introduce a notion of the $\chi-CLASS$ operators, which is a class including hyponormal operators and consider their spectral properties related to Weyl spectra.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.519-523
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• 2004

In this paper, a simple power control scheme of Class-D inverter, which is varied duty cycle of fixed frequency to desired output power. It is more suitable and acceptable for high-frequency induction heating (IH) jar applications. The proposed control scheme has the advantages of not only wide power regulation range but also ease to control output power. Also it can achieve the stable and efficient Zero-Voltage-Switching (ZVS) in whole load range. The control principles of proposed method are described in detail and its validity is verified trough simulations results on 38.5kHz IGBT for induction heating rated on 1.6kW with constant frequency variable power.

• Journal of Power Electronics
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• v.5 no.4
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• pp.272-281
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• 2005

In this paper, a simple power control scheme for a constant frequency Class-D inverter with a variable duty cycle is proposed. It is more suitable and acceptable for high- frequency induction heating (IH) jar applications. The proposed control scheme has the advantages of not only wide power regulation range but also ease of control output power. Also it can achieve a stable and efficient Zero-Voltage-Switching (ZVS) in a whole load range. The control principles of the proposed method are described in detail and its validity is verified through simulated and experimental results on 42.8kHz IGBT for induction heating rated on 1.6kW with constant frequency variable power.

• Journal of the Korean Mathematical Society
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• v.40 no.2
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• pp.273-286
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• 2003

Let $F^{\alpha}$G be a twisted group algebra. A subalgebra of $F^{\alpha}$G generated by all class sums of partition P of G is called a projective class algebra in $F^{alpha}$G associated with partition P. In this paper we study various partitions of G determined by actions of certain operator groups on G and construct projective class algebras depending on the actions. With regard to projective class algebras, we investigate structures of associated skew group algebras and fixed group algebras.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1009-1011
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• 2001

This paper presents a new hybrid control scheme using Active-Clamped Class-E (ACCE) inverter of induction heating(IH) jar for high power applications. The proposed hybrid control scheme has characteristics, which act as class-E inverter at lower switch voltage and ACCE inverter at higher switch voltage than reference voltage of the main switch by feeding back voltage one as well as advantages of conventional ACCE inverter such as zero-voltage switching(ZVS) of the main switch and the reduced switch voltage due to the clamping circuit. Moreover, the proposed control method makes higher output power than conventional ACCE inverter control one since ACCE inverter is operated like class-E inverter at low voltage condition. The principle of the proposed control are explained in detail and the validity of the proposed control scheme is verified through the several interesting simulated and experimental results.

• Journal of Environmental Health Sciences
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• v.20 no.4
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• pp.17-35
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• 1994

This study was performed to investigate and assess the heavy metal contamination of sediment in main stream and tributaries of the Han-river in the vicinity of Seoul. Sediment were sampled at eight locations of main stream and eighteen locations of tributaries in the spring, summer, and fall in 1993. Six heavy metals of Cd, Cu, Pb, Zn, Cr, and Hg, were assessed. For an assessment of heavy metal contamination in sediment, the assessment method of Hakanson was modified to estimate for Han-river, then classification method of Muller in sediment quality was applied. For an assessment of contamination in each heavy metal, Contamination factor C$_f^i$ which was defined the ratio of concentration of i heavy metal in investigated location to background concentration of i heavy metal in uncontaminated upper area was used. The sediment quality in each heavymetal was classified as follows if C$_f^i$<1, Class I for Non contamination, if 1 < C$_f^i$ < 3, Class II for Low contamination, if 3< C$_f^i$ <6, Class III for Moderate contamination, if 6< C$_f^i$ <12, Class IV for Considerable contamination, and if C$_f^i$ > 12, Class V for High contamination.(abbreviation)

• Journal of Species Research
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• v.10 no.3
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• pp.227-236
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• 2021

To obtain unrecorded freshwater bacterial species in Korea, water and sediment samples were collected from streams, lakes, and wetland of the Han River watershed in 2020. Approximately 800 bacterial strains were isolated on R2A agar after aerobic or anaerobic incubation, and identified using 16S rRNA gene sequences. A total of 28 strains, with ≥98.7% 16S rRNA gene sequence similarity with validly published bacterial species but not reported in Korea, were determined to be unrecorded bacterial species in Korea. The unrecorded bacterial strains were phylogenetically diverse and belonged to four phyla, eight classes, 13 orders, 19 families, and 25 genera. The unreported species were assigned to Acetobacter, Alsobacter, Mesorhizobium, Prosthecomicrobium, and Microvirga of the class Alphaproteobacteria; Vogesella, Formosimonas, Aquincola, Massilia, Acidovorax, and Brachymonas of the class Betaproteobacteria; Pseudoxanthomonas, Thermomonas, Lysobacter, Enterobacter, Kosakonia, and Acinetobacter of the class Gammaproteobacteria; Sulfuricurvum of the class Epsilonproteobacteria; Mycolicibacterium, Agromyces, Phycicoccus, and Microbacterium of the class Actinobacteria; Paenibacillus of the class Bacilli; Clostridium of the class Clostridia; and Flavobacterium of the class Flavobacteriia. The details of the unreported species, including Gram reaction, colony and cell morphology, biochemical characteristics, and phylogenetic position are also provided in the description of the strains.