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Showing papers by "Kyungpook National University published in 1995"


Journal ArticleDOI
01 Dec 1995
TL;DR: In this paper, a closed loop image segmentation system which incorporates a genetic algorithm to adapt the segmentation process to changes in image characteristics caused by variable environmental conditions such as time of day, time of year, clouds, etc.
Abstract: We present the first closed loop image segmentation system which incorporates a genetic algorithm to adapt the segmentation process to changes in image characteristics caused by variable environmental conditions such as time of day, time of year, clouds, etc. The segmentation problem is formulated as an optimization problem and the genetic algorithm efficiently searches the hyperspace of segmentation parameter combinations to determine the parameter set which maximizes the segmentation quality criteria. The goals of our adaptive image segmentation system are to provide continuous adaptation to normal environmental variations, to exhibit learning capabilities, and to provide robust performance when interacting with a dynamic environment. We present experimental results which demonstrate learning and the ability to adapt the segmentation performance in outdoor color imagery.

324 citations


Journal ArticleDOI
TL;DR: Two new Late Cretaceous ichnospecies are named on the basis of tracks of birds with webbed feet discovered in the Uhangri Formation, Hwangsan Basin of South Korea as discussed by the authors.
Abstract: Two new Late Cretaceous ichnospecies are named on the basis of tracks of birds with webbed feet discovered in the Uhangri Formation, Hwangsan Basin of South Korea. The first, Uhangrichnus chuni ichnogen. et ichnosp. nov., is based on a large sample of small tracks, whereas the second, Hwangsanipes choughi ichnogen. et. ichnosp. nov., is based on a single trackway of a larger bird from the same stratigraphie level. The tracks form part of a high density track assemblage in lacustrine shoreface sediments and are the oldest traces of web‐footed birds so far reported. A third, Early Tertiary ichnospecies, Presbyorniformipes feduccii ichnogen. et ichnosp. nov., is named on the basis of trackways and feeding trails of a bird with webbed feet from the Early Eocene Green River Formation of eastern Utah. This previously unnamed track type has already been attributed to the Eocene shorebird Presbyornis and cited as an example of trace‐fossil evidence for feeding behavior in a lakeshore setting. Although this attrib...

87 citations


Journal ArticleDOI
TL;DR: The patient was a 56-year old male who visited an otolaryngology clinic due to foreign body sensation and pain of the pharyngeal region for 3-4 days because he used to eat raw fresh-water fish.
Abstract: The authors present the first human case of Clinostomum pharyngitis in Taegu, Korea. The patient was a 56-year old male who visited an otolaryngology clinic due to foreign body sensation and pain of the pharyngeal region for 3-4 days. He used to eat raw fresh-water fish. Otolaryngological examinations revealed a living worm adhered to the right posterior pharyngeal wall. The worm removed was identified as C. complanatum after morphological observations. It is likely that more attention should be paid to eating raw fresh-water fish in Korea with regards to Clinostomum pharyngitis.

71 citations


Journal ArticleDOI
TL;DR: In this paper, Phillipsite was synthesized from the silica-poor fly ash by the hydrothermal treatment with 2N-NaOH solution at 105°C.
Abstract: Phillipsite was synthesized from the silica-poor fly ash by the hydrothermal treatment with 2N-NaOH solution at 105°C. Most of phillipsite was synthesized between 2 hrs. and 6 hrs. in the reaction time. The phillipsite synthesis mainly depended on the Al concentration of the liquid phase, and was taken place from the dissolution of the silicate glass and the amorphous Al compound. The cation exchange capacity (CEC) of the synthesized phillipsite was 198 meq/100g. The suggested process of phillipsite synthesis was (1) the dissolution of amorphous materials and condensed compounds of fly ash, (2) the dissolution of the sphere matrix of fly ash particles, (3) the supersaturation of liquid phase, (4) the phillipsite formation, and (5) the growth of phillipsite crystal.

69 citations


Journal ArticleDOI
TL;DR: In this paper, the authors explored the relationship between the technological acquisition strategies of small firms and innovation in the Korean electronics industry and found that in-house R&D and technical linkages with buyers and suppliers have stronger effects on radical innovation in a new technology setting than in a traditional technology setting.

60 citations


Journal ArticleDOI
TL;DR: A self-tuning fuzzy water level controller based on real-time tuning of the scaling factors for the steam generator of a nuclear power plant is presented and simulation results show that the proposed tuning method improves the performance of the waterlevel controller.

49 citations


Journal ArticleDOI
TL;DR: Down regulation of PKC blocked both proliferation of cells and synthesis of sulfated proteoglycans, indicating that expression of cPKC and nPKC is required at early stage of chondrogenesis.

46 citations


Journal ArticleDOI
01 Jun 1995
TL;DR: In this paper, an adaptive update-rate target tracking algorithm is proposed for a phased-array radar, which is based on the interacting-multiple-model (IMM) algorithm.
Abstract: An adaptive-update-rate target-tracking algorithm is proposed for a phased-array radar. The algorithm is based on the interacting-multiple-model (IMM) algorithm. The purpose of this IMM algorithm is twofold: to estimate and predict the target states; and to estimate the level of the dynamic process noise. The estimate of the process-noise level is used to determine the update interval adapted to the changing target dynamics. The update interval is determined so that the number of track updates per unit time in reflection of beam-positioning losses can be reduced. The proposed algorithm is implemented for a phased-array radar tracking and evaluated with Monte Carlo simulations on various trajectories. The evaluation results of the proposed algorithm are presented and compared with the results of the 'cube-root filter'.

41 citations


Journal ArticleDOI
TL;DR: In this article, solid-electrolyte sensors using NASICON for detecting CO2 gas are prepared by the sol-gel method, and phase identification is carried out by X-ray diffractometry (XRD).
Abstract: Solid-electrolyte sensors using NASICON for detecting CO2 gas are prepared by the sol-gel method. Starting materials are the alkoxides Si(OC2H5)4, Zr(OC2H7)4 and NaOC2H5. Because of their fine powders, the sintering temperature can be low. The phase identification is carried out by X-ray diffractometry (XRD). E.m.f. cells are constructed by fixing the NASICON disk to the end of a quartz tube with an inorganic adhesive. The devices with (Li, Ba)CO3 as sensing electrode and air as reference electrode show high sensitivity to 300–5000 ppm CO2 gas and good stability for a sintering temperature of 1000 °C.

41 citations


Journal ArticleDOI
TL;DR: The effect of Mn on the PTCR characteristics of La-doped BaTiO 3 ceramics was studied in this paper, where acceptor state density was measured from a ρ-1/T graph as a function of Mn concentration and the behavior of room temperature resistivity with Mn concentration was explained by compensation of acceptors at grain boundaries.
Abstract: The effect of Mn on the PTCR characteristics of La-doped BaTiO 3 ceramics was studied. Acceptor state density was measured from a ρ-1/T graph as a function of Mn concentration. The behavior of room-temperature resistivity with Mn concentration was explained by compensation of acceptors at grain boundaries. The valence state of Mn was analyzed by ESR, and it changed near the Curie temperature of BaTiO 3 from 3+ in tetragonal phase to 2+ in cubic phase. Therefore, the number of electron traps increased at the Curie temperature, leading to the great improvement in the PTCR effect. The valence change of Mn ions was explained by vanishing of the Jahn-Teller effect as the phase changes from tetragonal to cubic.

39 citations


Journal ArticleDOI
TL;DR: In this paper, a series of catalysts, NiO-ZrO 2 /SO 4 2−, for ethylene dimerization were prepared by coprecipitation from a solution of a nickel chloride-zirconium oxychloride mixture followed by modifying with H 2 SO 4.
Abstract: A series of catalysts, NiO—ZrO 2 /SO 4 2− , for ethylene dimerization were prepared by coprecipitation from a solution of a nickel chloride-zirconium oxychloride mixture followed by modifying with H 2 SO 4 . On the basis of the results obtained from X-ray diffraction and differential thermal analysis, the addition of nickel oxide to ZrO 2 or modification with H 2 SO 4 shifted the transition of ZrO 2 from amorphous to a tetragonal phase at higher temperatures due to the interaction between nickel oxide (or sulfate ion) and ZrO 2 . Infrared spectra of the catalyst modified with H 2 SO 4 showed bidentate sulfate ion coordinated to Zr 4+ or Ni 2+ . NiO—ZrO 2 without sulfate ion was inactive for the ethylene dimerization, but NiO—ZrO 2 /SO 4 2− was found to be very active even at room temperature. The high catalytic activity of NiO—ZrO 2 /SO 4 2− was closely correlated with the increase of acid strength by the inductive effect of sulfate ion. The decrease of catalytic activity above 450°C of evacuation temperature was due to the structural change from amorphous phase to crystalline and the sintering followed by the decrease of surface area.

Journal ArticleDOI
TL;DR: This survey demonstrated for the first time the source of human infection by C. complanatum in Korea, identified as Uisong-gun, Kyongsangbuk-do, Korea, by morphological observation and experimental infection to chicks.
Abstract: A species of metacercariae recovered from the fresh-water fish, collected from Kaumji (Pond), Kaechonji (Pond) and Ssanggyechon (River), Uisong-gun, Kyongsangbuk-do, Korea, was identified as Clinostomum compzcnatum by morphological observation and experimental infection to chicks. The excysted metacercariae, tongue-shaped and progenetic, were 3.28-4.27 mm in length and 0.94-1.46 mm in width. The adult flukes recovered from the chicks four days after infection were 4.20-4.86 mm long and 1.14-1.49 mm wide. Twelve species of the fresh-water fish were found to be infected with the metacercariae. The infection rate ranged from 1.6% (Zacco temminkii) to 88.9% (Acheilognathus rhombec and Microphwsogobio voluensis) . The intensity was highest in Cnrqssius curatus (13.0/fish infected) and the abundance (relative densityl was highest in A. rhombea (7.8/fish examined). This survey demonstrated for the first time the source of human infection by C. complnnntum in Korea. Key words: Clinostomw coWLunatul metacercariae, second intermediate hosts, fresh- water fish, Uisong-gun, Korea

Journal ArticleDOI
TL;DR: In this paper, the wear and friction data indicate that a transition in wear mechanism occurs abruptly after a defined period of sliding, and that the transition point is reached earlier as load increases.
Abstract: Wear mechanisms in SiC during sliding have been investigated experimentally under paraffin oil lubrication. The wear and friction data indicate that a transition in wear mechanism occurs abruptly after a defined period of sliding. The transition point is reached earlier as load increases. Examination of wear samples reveals that surface material is predominantly removed by a plastic grooving process in the initial stage, and by a grain pull-out process after the transition. It is also observed that severe plastic deformation in the form of dislocations is produced during the sliding. The abrupt occurrence of the grain pull-out after a definite sliding time is discussed in relation to the internal stresses associated with this plastic deformation.

Journal ArticleDOI
TL;DR: In this paper, a rapidly solidified Al 88 Ni 10 − X (Nd,Gd) 2 Fe X (X = 0 or 1 at%) amorphous alloys aged for 60 s at temperatures below the precipitation temperature of the compounds.
Abstract: Ultrahigh tensile strength was found in a rapidly solidified Al 88 Ni 10 − X (Nd,Gd) 2 Fe X (X = 0 or 1 at%) amorphous alloys aged for 60 s at temperatures below the precipitation temperature of the compounds. The aged alloys have a mixed structure consisting of Al particles with the size of 10 nm and interparticle spacing of 3 to 7 nm embedded in an amorphous matrix. The maximum σ f value of 1980 MPa in the mixed Al 88 Ni 10 Nd 2 alloy was obtained at V f = 18%. This value is 1.6 times higher than that of the amorphous single phase state with the same composition. This increase in σ f is thought to be due to the dispersion strengthening of the defect-free Al nanoparticles which have higher mechanical strength compared with that of amorphous matrix. On the other hand, the ultimate tensile strength ( σ B ) for the mixed Al 88 Ni 10 Nd 2 alloy with 8% V f keeps higher level than that for amorphous single phase at elevated temperatures and shows high value of 1000 MPa even at 580 K This value is about 15 times higher than that for typical age-hardening type Al alloys. The reason for the high-temperature strength in this alloy is thought to be due to the high structural stability of the nanocrystalline Al particles and an enhanced thermal stability in the amorphous matrix by the depletion of Al resulting from the precipitation of the Al particles.

Journal ArticleDOI
TL;DR: In this article, partially hydrated silica (H-SiO2) was chosen for reaction with trialkylaluminum (AIR3) to prepare catalyst precursor, and the analysis data of silica surface by BET and CP MAS 13C NMR revealed that the catalyst precursor was methylaluminoxane (PMAO) supported on silica.
Abstract: To prepare supported catalyst for ethylene polymerization, silica was treated with trialkylaluminum (AIR3) followed by supporting Cp2ZrCl2. Partially hydrated silica (H-SiO2) was chosen for reaction with AIR3 to prepare catalyst precursor. The H-SiO2/ AIR3 / Metallocene catalyst system could effectively catalyse ethylene polymerization even with common alkylaluminums as cocatalyst. The catalytic activity of supported catalyst depended on H2O content of silica. H2O/(CH3) 3Al ratio, metallocene and cocatalyst. The analysis data of silica surface by BET and CP MAS 13C NMR revealed that the catalyst precursor prepared from the reaction between H-SiO2 and (CH3) 3Al was methylaluminoxane (PMAO) supported on silica with high surface area and reduced pore size.

Journal ArticleDOI
TL;DR: In this paper, the interaction of oxygen with a V(110) surface, in the temperature range of 80-1200 K, has been investigated by using high-resolution electron energy loss spectroscopy (HREELS) and near-edge X-ray absorption fine structure (NEXAFS) techniques.

Journal ArticleDOI
TL;DR: Two kinds of trisiloxane-bridged dinuclear titanium metallocene-type complexes were synthesized in this paper, i.e., monocyclopentadienyl and biscyclopentadiene dinuclear titanocenes with trisILoxane bridges.
Abstract: Two kinds of the trisiloxane-bridged dinuclear titanium metallocene-type complexes were synthesized. They are monocyclopentadienyl and biscyclopentadienyl dinuclear titanocenes with trisiloxane bridges. The above complexes with modified methylaluminoxane (MMAO) cocatalyst initiate the polymerizations of ethylene and styrene to produce high-density polyethylene and syndiotactic polystyrene. In addition, a copolymer of ethylene and styrene was obtained.

Journal ArticleDOI
TL;DR: Mt DNA fingerprinting was found to be highly applicable for the strain identification, characterization, and differentiation of Acanthamoeba.
Abstract: Interstrain polymorphisms of isoenzyme profiles and mitochondrial (Mt) DNA fingerprints were observed among seven strains of Acnnthnmoeba isolated from different sources and morphologically assigned to A. polvphngn. Mt DNA ringerprints by eight restriction endonucleases (Bgl II, Sca I, Cla I, EcoR I, Xbo I, Kpn I, Sal I, and Sst I) revealed considerable interstrain polymorphisms . Isoenzyme profiles revealed considerable interstrain polymorphisms for acid phosphatase, lactate dehydrogenase, and glucose-6- phosphate dehydrogenase while those for glucose phosphate isomerase , leucine aminopeptidase , and malate dehydrogenase showed similarity Despite of the interstrain polymorphisms, the isoengyme profiles and Mt DNA fingerprints of the strain Ap were found to be identical with those of the strain .tones . Mt DNA fingerprinting was found to be highly applicable for the strain identification, characterization, and differentiation. Key words: Acanthnmoebn polyphcga, interstrain polymorphism, isoenzyme profiles , Mt DNA fingerprints, strain differentiation, strain identification.

Journal ArticleDOI
TL;DR: In the presence of boron trifluoride etherate, aryl and alkylthioamides react with ethyl diazopyruvate to give high yields of corresponding thiazoles as mentioned in this paper.

Journal ArticleDOI
TL;DR: This paper shows that a large inference error is generated when the Gupta's decomposition method (1986) is applied to Exclusive-nor (ENOR) gate model which is used as a counter example and defines an index of applicability which can classify whether the decomposition methods can be applied to a multivariable fuzzy system or not.
Abstract: Research on the application of fuzzy set theory to the design of control systems has led to interest in decomposition of multivariable fuzzy systems. Decomposition of multivariable control rules is preferable since it alleviates the complexity of the problem, but the inference error is inevitable because of its approximate nature. In this paper we show that a large inference error is generated when the Gupta's decomposition method (1986) is applied to Exclusive-nor (ENOR) gate model which is used as a counter example. We define an index of applicability which can classify whether the decomposition method can be applied to a multivariable fuzzy system or not. >

Journal ArticleDOI
TL;DR: Intracerebroventricular administration of losartan and saralasin produced remarkably similar effects on the cardiovascular, vasopressin, and renin responses to hemorrhage, suggesting that brain ANG II acting through AT1 receptors plays an important physiological role in mediating rapid cardiovascular regulation and vasoppressin release in response to hemorrhages.
Abstract: The role of brain angiotensin II (ANG II) in mediating cardiovascular, vasopressin, and renin responses to hemorrhage was assessed in conscious spontaneously hypertensive rats (SHR) and in normotensive Wistar-Kyoto (WKY) and Wistar rats. Intracerebroventricular administration of losartan (10 micrograms) and saralasin (1 microgram.microliter-1.min-1) produced a markedly greater fall in blood pressure and a reduced tachycardia during and after hemorrhage (15 ml/kg) compared with the artificial cerebrospinal fluid control in SHR and Wistar rats but not in WKY rats. Vasopressin release after hemorrhage was also impaired, but renin release was enhanced by intracerebroventricular ANG II antagonists in SHR and Wistar rats but not in WKY rats. Losartan and saralasin produced remarkably similar effects on the cardiovascular, vasopressin, and renin responses to hemorrhage. These data suggest that brain ANG II acting through AT1 receptors plays an important physiological role in mediating rapid cardiovascular regulation and vasopressin release in response to hemorrhage. The relative importance of brain angiotensin system may vary in different strains of rate.

Journal ArticleDOI
TL;DR: In this paper, the photon structure function F 2 γ has been measured at average Q 2 values of 73 and 390 GeV 2 using data collected by the AMY detector at the TRISTAN e + e − collider.

Journal ArticleDOI
TL;DR: In this article, the physicochemical properties of soybean oil extracted from γ-irradiated soybeans (0-10kGy) were investigated, and no significant changes were observed in the total lipid content, fatty acid composition, acid value, peroxide value and trans fatty acid content at different irradiation doses.

Journal ArticleDOI
TL;DR: In this article, the effect of various factors on the stamping formability of sheet materials were analyzed by experiments designed according to the orthogonal array of the Taguchi method.

Journal ArticleDOI
TL;DR: The palladium catalyzed carbonylative cyclization of o-bromobenzaldehyde in alcoholic solution gave 3-alkoxyphthalides 3a-e in 61-85% isolated yields via intramolecular cyclization induced by the coordinated formyl group on the palladium as mentioned in this paper.

Journal ArticleDOI
TL;DR: Fixed and preserved blood smears of malaria patients were used for comparative analysis of AO and Giemsa stains and the AO staining method provided an alternative toGiemsa for malaria diagnosis in the field and laboratory.
Abstract: Recently, the Acridine orange (AO) staining method has improved for identification of malaria parasites. Fixed and preserved blood smears of malaria patients were used for comparative analysis of AO and Giemsa stains. The AO staining method required less time and was more sensitive under lower magnification than the Giemsa staining method. The AO staining method provides an alternative to Giemsa for malaria diagnosis in the field and laboratory.

Journal ArticleDOI
TL;DR: A VLSI architecture of the block matching algorithm based on the alternative subsampling method for motion estimation is proposed that can achieve approximately N/2 times of calculation with an additional small overhead associated with the address generator and temporary buffer.
Abstract: A VLSI architecture of the block matching algorithm based on the alternative subsampling method for motion estimation is proposed. The alternative subsampling method reduces the computational complexity by alternatively subsampling the number of pixels within the blocks used to estimate motion vectors, whereas conventional methods limit the number of locations searched. Simulation results show that the performance of this method is very close to full search algorithm. For a subsampling factor of N, this approach can achieve approximately N/2 times of calculation with an additional small overhead associated with the address generator and temporary buffer. In addition, this architecture has about a half of the silicon area compared to Yang's (1989) architecture. >

Proceedings ArticleDOI
25 Jun 1995
TL;DR: In this article, the steady-state thermal analysis by finite-element method was performed to optimize the thermal properties of gas sensor and to reduce operating power and heat transfer to peripheral IC circuit.
Abstract: The stable and low power heating characteristics of a microheater are very important for the micro gas sensor. The membrane type gas sensors were fabricated by silicon IC technology. The steady-state thermal analysis by finite-element method was performed to optimize the thermal properties of gas sensor and to reduce operating power and heat transfer to peripheral IC circuit. The heating characteristics of fabricated poli-Si and Pt heaters were examined.


Journal ArticleDOI
TL;DR: In this paper, the uniformly elliptic operator was considered and its discretization based on the cubic spline spaces and collocation at the Gauss points was studied. But the results of the results were not discussed.
Abstract: This work considers the uniformly elliptic operator $A$ defined by $Au := \ -\Delta u + a_1 u_x + a_2 u_y + a_0 u$ in $\Omega$ (the unit square) with boundary conditions: $u \ = \ 0 $ on $\Gamma_0$ and ${{\partial u} \over {\partial u }} = \alpha u$ on $\Gamma_1$ and its discretization based on Hermite cubic spline spaces and collocation at the Gauss points. Using an interpolatory basis with support on the Gauss points one obtains the matrix $\hat A_N (h = {1 \over N} )$ . We discuss the $H^1$ condition numbers and the distribution of $\tilde \beta_N $ -singular values of the preconditioned matrices $(\tilde \beta_N )^{-1} \hat A_N$ where $\tilde \beta_N$ is the stiffness matrix associated with the finite element discretization of the positive definite uniformly elliptic operator $B$ given by $B v := - \Delta v + b_0 v$ in $\Omega$ with boundary conditions: $v \ = \ 0$ on $\Gamma_0 , \ {{\partial v } \over {\partial u}} \ = \ \beta v$ on $ \Gamma_1$ . The finite element space is either the space of continuous functions which are bilinear on the rectangles determined by Gauss points or the space of continuous functions which are linear on the triangles of the triangulation of $\Omega$ using the Gauss points. When $A \ = \ B$ we obtain results on the eigenvalues of $\tilde \beta_N^{-1} \hat A_N$ . In the general case we obtain bounds and clustering results on the $\tilde \beta_N$ -singular values of $\tilde \beta_N^{-1} \hat A_N$ . These results are related to the results of Manteuffel and Parter [MP], Parter and Wong [PW], and Wong [W] for finite element discretizations as well as the results of Parter and Rothman [PR] for discretizations based on Legendre Spectral Collocation.