• The Korean Journal of Nuclear Medicine
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• v.38 no.6
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• pp.486-491
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• 2004

Purpose: factor analysis and independent component analysis (ICA) has been used for handling dynamic image sequences. Theoretical advantages of a newly suggested ICA method, ensemble ICA, leaded us to consider applying this method to the analysis of dynamic myocardial $H_2^{15}O$ PET data. In this study, we quantified patients' blood flow using the ensemble ICA method. Materials and Methods: Twenty subjects underwent $H_2^{15}O$ PET scans using ECAT EXACT 47 scanner and myocardial perfusion SPECT using Vertex scanner. After transmission scanning, dynamic emission scans were initiated simultaneously with the injection of $555{\sim}740$ MBq $H_2^{15}O$. Hidden independent components can be extracted from the observed mixed data (PET image) by means of ICA algorithms. Ensemble learning is a variational Bayesian method that provides an analytical approximation to the parameter posterior using a tractable distribution. Variational approximation forms a lower bound on the ensemble likelihood and the maximization of the lower bound is achieved through minimizing the Kullback-Leibler divergence between the true posterior and the variational posterior. In this study, posterior pdf was approximated by a rectified Gaussian distribution to incorporate non-negativity constraint, which is suitable to dynamic images in nuclear medicine. Blood flow was measured in 9 regions - apex, four areas in mid wall, and four areas in base wall. Myocardial perfusion SPECT score and angiography results were compared with the regional blood flow. Results: Major cardiac components were separated successfully by the ensemble ICA method and blood flow could be estimated in 15 among 20 patients. Mean myocardial blood flow was $1.2{\pm}0.40$ ml/min/g in rest, $1.85{\pm}1.12$ ml/min/g in stress state. Blood flow values obtained by an operator in two different occasion were highly correlated (r=0.99). In myocardium component image, the image contrast between left ventricle and myocardium was 1:2.7 in average. Perfusion reserve was significantly different between the regions with and without stenosis detected by the coronary angiography (P<0.01). In 66 segment with stenosis confirmed by angiography, the segments with reversible perfusion decrease in perfusion SPECT showed lower perfusion reserve values in $H_2^{15}O$ PET. Conclusions: Myocardial blood flow could be estimated using an ICA method with ensemble learning. We suggest that the ensemble ICA incorporating non-negative constraint is a feasible method to handle dynamic image sequence obtained by the nuclear medicine techniques.

• Applied Biological Chemistry
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• v.29 no.2
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• pp.212-218
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• 1986

Proteins in Korean rapeseeds, as in many other plantseeds, are usually bound to phytate molecules. These phytate-bound proteins are of little value as foodstuffs because of their poor solubility in digestive systems. Therefore it is necessary to remove phytates from proteins in order to convert these proteins io a useful foodstuff. In the work, an efficient procedure for removal of phytates from defatted Korean rapeseed was found. The influence of pH on the solubility of protein and phytate of rapeseed flour showed that the former was the lowest at pH 5.0 and began to increase as pH further raised. Meanwhile, the latter was the highest at pH 6.0, however, it was decreased abruptly at alkaline pH, especially to content of 1.3% at pH 11.5. The solubility cf protein was relatively high in NaCl aqueous solution at $pH\;6.0{\sim}8.0$, and did not male any noticeable difference depending on NaCl concentration. On the other hand, the solubility of phytate was high at pH of below 6.0 showing an abrupt decrease at pH of above 6.0. The solubility of protein in $CaCl_2$ aqueous solution was highest at $pH\;6.0{\sim}8.0$, however, there was no significant change at the whole range of tested pH of the solution. A maximum solubility of phytate was shown at $pH\;3.0{\sim}4.0$. And it was decreased abruptly at a higher pH of the above range and also decreased at a lower pH with higher $CaCl_2$ concentration. The solubility of phytate in $Na_2SO_3$ aqueous solution was highest at $pH\;5.0{\sim}8.0$. As the concentration goes up the maximum value of solubility was found to move to higher pHs. Depending on the concentration of $Na_2SO_3$, the decreasing pattern was changed in an alkaline solution. The solubility of phytate in the solution containing low concentration of $Ca^{2+}$ ion was low in all treatments at pH of above 7.0 and showed the maximum value at low pH as $Ca^{2+}$ ion concentration increases. The solubility of protein at pH 11.5 showed the highest value in $1mM\;Ca^{2+}$ ion solution.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.4 no.1
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• pp.31-41
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• 1971

The present study was directed to define the degradation pattern of the nucleotides and their related compounds in the muscle of anchovy during drying. Three kinds of samples, fresh, sun dried and boiled-and-dried anchovy, were prepared and the contents of nucleotides and related compounds of samples were determined by ion exchange chromatography. The results obtained are summarized as follows: Almost all of ATP disappeared in both muscle of sun dried and boiled-and-dried anchovy, although the initial content of ATP in fresh muscle was very low ($1.8{\mu}moles/g$, dry basis). But the remainning amount of ADP was considerably high while the other nucleotide almost entirely disappeared. This suggested that the residual ADP is responsible to the 'bound nucleotide' of myofibrils. In general, AMP content was comparatively lower than that of other nucleotides. Among three samples, the boiled-and-dried sample showed relatively higher AMP value than others. The amount of IMP remained in muscle remarkably varied between the boiled-and-dried anchovy and sun dried anchovy, the former's value being sixteen times higher than that of latter. In the contents of inosine and hypoxanthine, the sun dried anchovy marked an exceedingly high value equivalent to 2.7 times of the boiled-and-dried anchovy. In comparison of the ratio of inosine and hypoxanthine, hypoxanthine was accumulating in boiled-and-dried anchovy whereas inosine was in the sun-dried anchovy. Eighty three percent of total nucleotides in the fresh anchovy retained in the boiled-and-dried anchovy and IMP ratio in total nucleotides was $73\%$. On the contrary, the sun dried anchovy showed barely $10\%$ of retention rate and IMP ratio was only $38\%$. Considered from the flavor quality of dried anchovy, so far as concerned IMP content, it may be said that the boiled-and-drying method is more favorable process for dried product of anchovy than the sun-drying method.

• Parasites, Hosts and Diseases
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• v.24 no.2
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• pp.187-193
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• 1986

Enzyme-linked immunosorbent assay(ELISA) using crude and affinity-purified antigens of adult worms of Paragonimus westermani was performed for infected cat sera with different worm burden, from preinfection to 18th week after infection. Crude antigen was used with supernatant of homogenated worms by freezing-thawing method, and the supernate was centrifuged for 1 hour at 10,000 rpm at $4^{\circ}C$. Affinity-purified antigen(antibody-bound antigen) was prepared from fractions(bound and unbound) of crude antigen by affinity chromatography on CNBr-activated sepharose 4B, and IgG as a ligand was prepared from paragonimiasis cat serum(6 months infected) obtained by ammonium sulfate ($40%{\sim}45%$ saturated) precipitation method. By SDS-PAGE, crude antigen showed 22 polypeptide fractions while purified antigen showed 4 fractions: 36, 400, 34, 700, 27, 600 and 11, 500 in molecular weights. All cats were divided into five groups($G_1-G_5$) by different worm burdens. The mean of recovered worms(${\pm}SD$) and the number of cats in each group are as follows: $G_1$, 2 worms(0) and 4 cats; $G_2$, 4.75 (${\pm}0.66$) and eight; $G_3$, 10.75(${\pm}1.92$) and four; $G_4$, 23.20(${\pm}3.43$) and five; $G_5$, 48(${\pm}12.63$) and five cats. The results were summarized as follows: 1. The antibody levels(OD value) increased by worm burden in $G_1$ to $G_4$ generally. However, individual antibody levels were not exactly related with worm burden in all groups, especially there was a wide difference in $G_4$ and $G_5$. These results suggested that the worm burden in $G_4$ (about $20{\sim}30$ worms) is enough to produce antibody maximum in cats of $2{\sim}3kg$ weight. 2. The antibody levels increased significantly(p<0.05) compared to control sera at the 3rd week in $G_1$ and $G_2$, at the 2nd week in $G_3$, and at the 1st week in $G_4$ and $G_5$. Especially in the 4th week, OD value increased more in $G_1$(p<0.01) and in $G_2$ to $G_5$(p<0.001). In the pattern of antibody levels by ELISA in each group, OD in $G_1$ increased to the 18th week continuously, in $G_2$ OD was maintained same after the 16th week, but in $G_3$ it decreased after the 16th week, and it was maintained same in $G_4$ and $G_5$ after the 14th week. 3. The antibody levels by ELISA with the affinity-purified antigen were higher than those with crude antigen in all groups generally. Especially, the difference of OD values between two antigens was larger from the 4th to the 10th week. In $G_1$ and $G_2$ OD with purified antigen was higher than that with crude one to the 18th week. It was also higher in $G_3$ than that with crude antigen to the 16th week and OD of $G_4$ and $G_5$ were higher before the 14th week than that with crude antigen, however became lower at the 16th week. Consequently, the antibody level in ELISA with affinity-purified antigen was more sensitive at the early weeks after infection and in light infection groups than that with crude antigen.

• Journal of Environmental Health Sciences
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• v.10 no.2
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• pp.9-40
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• 1984

This thesis purports to overview the diverse administrative and organizational factors and plannings developed by the government organizations, municipal or otherwise, to tackle the Han River water pollution issues in the past years. This thesis also looks into the ever-worsening Han River water pollution problems, in particular, in terms of the various government plans ostensibly designed to reduce the pollution level but with little success. Also dealt with are the efficiencies with which the laws and decrees on water pollution the administrative organizations put to use in the prosecution of the diverse antiwater pollution projects involving the Han River basin. From the early 1960's up to the 1970's the government had concentrated on the growth-oriented economic policy with the result that little attention had been paid to the water pollution and other environmental issues that are bound to arise from the massive economic growth. Belatedly, the five-year Hah River Development Project was initiated in 1982 with emphasis on reducing the water pollution level at Hah River to the minimum. The following are the gists of the thesis and recommendations for the future antiwater pollution plans by the administrative organizations: 1. Documents to date indicate that the irrigation projects along the Han River area had been the main focus of attention during the Yi Dynasty and under the Japanese rule of the country. 2. Despite that the water pollution issue became the subject of many debates among the academic and research institutions in the 1960's and in the 1970's, the administrative organizations in charge of the Han River water quality control failed to come up with a concrete plan for the river's water quality control. 3. Nevertheless, the water pollution of the Han River area in fact began in the 1950's, with the unprecedented concentration into Seoul of population and the industrial facilities on a larger scale, in particular, enforced by the government's strong growthoriented policy in its Economic Development plans in the 1960's. 4. Starting in the 1960's, the Han River water pollution level dramatically increased, but the government was reluctant to promulgate or put into effect strong measures to curb the many factors contributing to the river water pollution, thus worsening the environmental issues along the Han River basin. 5. The environmental protection law and other laws and decrees relating to the antiwater and air pollution issues that were subsequently put into effect underwent so many changes that efficient anti-water pollution policies could not be effected for the Han River basin. The frequent organizational reshuffle within the administrative units concerned with environmental problems has resulted in the undue waste in personnel management and finance. 6. The administration on the environmental protection could not be efficiently carried out due to the organizational overlapping. Under the existing law, frequent organizational frictions and inefficiency are bound to occur among the central government offices themselves, as well as between the central government and the Seoul city administration, and among the city's administrative offices over the conservation of the Han River basin and over the river's anti-water pollution issue. 7. In the planning and prosecution of the Han River project, political influences from the president down to the lower-level politicious appear to have been involved. These political influences in the past had certainly had negative influence on the project, nevertheless, it appears that in the recent years, these political influences are not all that negative in view of the fact that they serve as a positive contributing factor in developing a better water quality control project along the Han River basin. The following are a few recommendations based on the data from the thesis: First, officials in charge of the Han River water quality control should pay attention to a careful screening of the opinions and recommendations from the academic circles and from the public should be made so that the government could better grasp the core issues in the environmental problems that require preventive and other necessary measures. Second, vigorous redistribution policies of population and industrial facilities away from the Seoul area should be pursued. Third, the government should refrain from revising or revamping too frequently the laws and decrees on the anti-water pollution, which is feared to cause undue inconveniences in the environmental administration. Fourth, a large-scale streamlining should be made to the existing administrative organization in an effort to do away with the inter- and intra-organizational friction. It is recommended that a secretariat for the Hah River basis conservation be established. Fifth, High-level administrative officials, with a thorough knowledge and vision on the Han River water quality control, should be prepared to better deal with the budgeting and personnel management for the Han River water pollution control not only at the control government, but also at the Seoul city municipal government levels. Environmental issues should be kept distinct from political issues. Environmental issues should not serve as a window-dressing for sheer political purposes. Sixth, the Hah River proiect should also include, along with the main Han River basin, those areas covering North Han River, South Han River, and the tributaries to the main river basin. The 'Han River Basin Water Quality Control Board' should be established immediately as a means of strengthening the current Han River basin water quality control policy. Seventh, in drawing up the Han River proiect, the administrative officials should be aware that Han River basin is a life line for those people in the region, providing them with not only a sheer physical space, but with a psychological living space for their everyday life.

• Economic and Environmental Geology
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• v.27 no.6
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• pp.523-535
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• 1994

The strata-bound type iron ore bodies in the Chungju mine are interbedded with metamorphic rocks which are intruded by Mesozoic granitic rocks. The iron ore deposit occurs as layer or lens shape which are concordant with the metamorphic rocks. The iron ore is classified into banded and massive types based on the mode of texture and occurrence. Grain size and iron-oxides tend to become coarser toward massive ore than banded ore. Banded ores commonly contain internal layers defined by alternating magnetite- rich, hematite-rich, magnetite-hematite, and quartz-rich mesobands. The banded iron ore consists of hematite, magnetite, quartz, feldspar, and minor amounts of biotite, muscovite, chlorite, carbonates, epidote, allanite, and zircon. Massive ores which are characterized by high magnetite content occur in contact of granitic rocks. The massive iron ores consist mostly of magnetite and quartz, with minor amounts of hematite, pyrite, microcline, biotite, muscovite, chlorite, carbonates, epidote, allanite and zircon. Magnetite from banded and massive ores is almost pure $Fe_3O_4$ in composition, including 0.14 to 0.27 wt.% MnO and 0.10 to 0.15 wt.% MnO, respectively. Hematite of the ore contains 0.87 to 1.27 wt.% $TiO_2$ in banded ore and 3.44 to 6.96 wt.% $TiO_2$ in massive ore, respectively. Biotite shows a little compositional variation depending on ore types. Biotite of the banded ore has lower FeO, $TiO_2$ and $Al_2O_3$, and higher MgO and $SiO_2$ than the massive ore. The modes of occurrence and petrography of ore implies that massive ores might have been formed either under more reducing environments or higher temperature condition than banded ore. Banded ores might represent early episode of iron enrichment due to regional metamorphism. Massive ores might be related to the contact metamorphism resulting from late granitic intrusion.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.562-574
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• 2012

Simulation validation techniques which have been employed in most studies are statistical analysis, which validate a model with mean or variance of throughput and resource utilization as an evaluation object. However, these methods have not been able to ensure the reliability of individual elements of the model well. To overcome the problem, the weighted F-measure method was proposed, but this technique also had some limitations. First, it is difficult to apply the technique to complex system environment with numerous values of interarrival time because it assigns a class to an individual value of interarrival time. In addition, due to unbounded weights, the value of weighted F-measure has no lower bound, so it is difficult to determine its threshold. Therefore, this paper propose weighted F-measure technique with cluster analysis to solve these problems. The classes for the technique are defined by each cluster, which reduces considerable number of classes and enables to apply the technique to various systems. Moreover, we improved the validation technique in the way of assigning minimum bounded weights without any lack of objectivity.

• Journal of the Korean Chemical Society
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• v.42 no.2
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• pp.203-208
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• 1998

The photochemical reactivities of 2-halobenzyl phenyl ether, in which 2-halobenzyl moiety are tethered to phenyl moiety by the etheral alkyl linkage, has been studied. In the presence of nitrogen, the photochemical reaction of 2-chlorobenzyl phenyl ether (1) produces mainly phenol and photo-Fries type reaction products, while the corresponding bromo analog 2 produces photocyclization and photoreduced products, along with phenol and photo-Fries type products. The former result implies that since chlorine is bound to the benzyl ring firmly, the rather weaker $CH_{2}-O$ bond of 1 is cleavaged to produce the photo-Fries type product. The latter implies that the photoinduced fission of phenyl-bromine bond of 2 can compete with the fission of $CH_{2}-O$ bond, since the bond energy of phenyl-bromine is lower than that of phenyl-chlorine. Since by the presence of oxygen the formation of phenol is not affected much, the formation of photo-Fries type products is changed a little, and the formations of photocyclization and photoreduced products are affected effectively, a singlet state is involved in the formation of phenol, and both singlet and triplet state may be involved in the formation of photo-Fries type reaction, while a triplet state is involved in the formation of photocyclization and photoreduction products.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.1
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• pp.38-49
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• 1985

The water soluble organic fractions (WSOF) from an agricultural soil (W), a soil treated with sludge for 6 years ($WS_6$), a sludge-soil mixture incubated for one week ($WS_1$), and sewage sludge (SS) were extracted, purified, and characterized by elemental analysis, functional group determinations, infrared, UV-visible, and proton nuclear magnetic resonance spectrosocpy. The SS was characterized by higher organic H, N, and P contents, a higher H/C ratio, and a lower C/N ratio than W. Total acidity carboxyl and phenolic hydroxyl group contents were generally highest in SS, intermediate in $WS_6$ and $WS_1$, and lowest in W. Overall aromatic character and aromatic carboxyl group contents were highest in W, and lowest in SS. Aliphatic proton, aliphatic carboxyl, and phenolic hydroxyl group contents were highest in SS, and lowest in W. Protein decomposition products were the pronounced components in SS, and decreased in concentration as the sludge component in the mixtures decreased. The $^1H$-NMR spectra suggested that the SS-protons were bound to a wider range of functional groups than W-protons. Structural complexities around the aromatic protons followed the following order: SS>$WS_1$>$WS_6$>W.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.582-591
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• 2009

The pyramid graph is an interconnection network topology based on regular square mesh and tree structures. In this paper, we adopt a strategy of classification into two disjoint groups of edges in regular square mesh as a base sub-graph constituting of each layer in the pyramid graph. Edge set in the mesh can be divided into two disjoint sub-sets called as NPC(represents candidate edge for neighbor-parent) and SPC(represents candidate edge for shared-parent) whether the parents vertices adjacent to two end vertices of the corresponding edge have a relation of neighbor or shared in the upper layer of pyramid graph. In addition, we also introduce a notion of shrink graph to focus only on the NPC-edges by hiding SPC-edges in the original graph within the shrunk super-vertex on the resulting graph. In this paper, we analyze that the lower and upper bound on the number of NPC-edges in a Hamiltonian cycle constructed on $2^n\times2^n$ mesh is $2^{2n-2}$ and $3*(2^{2n-2}-2^{n-1})$ respectively. By expanding this result into the pyramid graph, we also prove that the maximum number of NPC-edges containable in a Hamiltonian cycle is $4^{n-1}-3*2^{n-1}$-2n+7 in the n-dimensional pyramid.