Showing papers by "Kyungpook National University published in 1992"
TL;DR: In this article, the occurrence, systematics, palaeobiological and evolutionary significance of Mesozoic bird and bird-like tracks are reviewed in the light of recent new discoveries in East Asia, Africa and North America.
Abstract: The occurrence, systematics, palaeobiological and evolutionary significance of Mesozoic bird and birdlike tracks are reviewed in the light of recent new discoveries in East Asia, Africa and North America. The most abundant footprint evidence currently comes from Lower Cretaceous deposits of East Asia and North America, where there is now a substantial track record for shorebirds. However, there is also a significant record of pre-Cretaceous bird-like tracks. The Cretaceous Jindong Formation of South Korea has recently yielded over 30 localities and stratigraphic levels, tripling the previous record worldwide and providing evidence of hitherto unknown large waders: Jindongornipes kimi ichnogen. et ichnosp. nov. Like other previously named ichnotaxa, this bird track type probably represents a charadriiform species. It is included with Ignotornis and Koreanaornis in the new ichnofamily Ignotornidae. Lower Cretaceous bird tracks are abundant, typically show high densities (100-300 tracks m 2 ) and often occur in association with invertebrate traces, inferred to have been made by the organisms on which the birds were feeding. Such track evidence suggests that waterbird communities were well-established by the end of the Early Cretaceous. This is about 30 Ma before the purported waterbird radiation inferred from Upper Cretaceous avian skeletal remains, but is consistent with hypotheses that suggest an ancestral shorebird stock. Bird and bird-like tracks from the Jurassic and Late Cretaceous are variable in morphology, still poorly understood, and sometimes attributed to small coelurosaurian dinosaurs. However, current evidence suggests that the Jurassic aviform ichnogenus Trisauropodiscus may be of avian origin. It is sufficiently distinct from typical grallatorid (coelurosaurian) tracks to warrant recognition of a new ichnofamily (Trisauropodiscidae), which includes the newly described ichnospecies Trisauropodiscus moabensis from North America. Bird and bird-like tracks from both the Jurassic and Cretaceous are shown to be much more abundant and distinctive than previously supposed. Moreover, they add significantly to our understanding of early avian evolution and palaeoecology, and provide insights into the timing of events in avian evolution.
162 citations
TL;DR: A new procedure for single hair transplantation using the Choi hair transplanter is presented, which provides obvious cosmetic advantages in hairline refinement and the reconstruction of eyebrows, eyelashes, beards, and pubic escutcheon.
Abstract: A new procedure for single hair transplantation using the Choi hair transplanter is presented. This operation provides obvious cosmetic advantages in hairline refinement and the reconstruction of eyebrows, eyelashes, beards, and pubic escutcheon. The surgical technique is described in detail.
71 citations
Book•
01 Apr 1992TL;DR: This book illustrates how several drop-in macromodels are interconnected to form an analog phase locked group in the circuit simulation program SPICE.
Abstract: Describes macromodelling with SPICE, the circuit simulation program It covers the applicability of SPICE macromodelling in education and industry 31 "drop-in" models, simulated and verified for use either singly or in groups to perform any analog signal processing function, are provided The book illustrates how several drop-in macromodels are interconnected to form an analog phase locked group
63 citations
Chuo University1, Niigata University2, Louisiana State University3, Virginia Tech4, University of South Carolina5, Ohio State University6, University of California, Davis7, University of Rochester8, Konan University9, University of Minnesota10, University of the Philippines11, Rutgers University12, Saga University13, Korea University14, Kyungpook National University15, Saitama University16
TL;DR: In this article, an experimental study of e+e−+ hadrons in the kinematic regime for which the process is interpreted as hadron production in collisions of almost real photons is presented.
46 citations
TL;DR: In this article, a thin oxide-based thin film was prepared by a screen printing technique for sensing hydrocarbon gases, and a conductive sensing material was synthesized by SbCl 5 addition to the precipitating solution.
44 citations
TL;DR: This paper conducted a comparative study to test for the presence of preferential positions in reports of anti-government uprisings in China and South Korea, finding that news reflect unquestioned collective universals.
Abstract: Operating from a premise that nevos is an embodiment of ideological preferences, this comparative study tests for the presence of preferential positions in reports of anti‐government uprisings in China and South Korea. Employing a thematic analysis, the findings support the proposition that news reflect unquestioned collective universals. However, rather than evidence of idio‐graphic articulations of capitalist societies, the authors suggest that these are nomothetic practices prevalent in all institutionalized mass media systems.
42 citations
TL;DR: Protoplasts were isolated from leaf mesophyll of hybrid poplar with a mean yield of 10.4 x 106 protoplasts per g fresh weight using a liquid plating method and an MS medium without NH4NO3, and multiple shoots were produced from protoplast-derived callus after root induction on half-strength MS medium that lacked growth regulators.
Abstract: Protoplasts were isolated from leaf mesophyll of hybrid poplar (Populus nigra X P. maximowiczii) with a mean yield of 10.4 x 106 protoplasts per g fresh weight using 2.0% Cellulase ‘Onozuka’ R-10, 0.8% Macerozyme R-10, 1.2% Hemicellulase, 2.0% Driselase, and 0.05% Pectolyase Y-23 with CPW salts solution containing 0.6 M mannitol, 0.002 M DTT, 3 mM MES at pH 5.6. A liquid plating method produced the highest frequency of dividing protoplasts (48.6%) using an MS medium without NH4NO3. The highest percent of colony formation was 22.8%, produced with fabric supported semi-solid (0.5% w/v) agar plating method using the same culture medium. Growing cell colonies and/or micro-calli were transferred to a fresh semisolid agar medium containing 0.44 μM BAP and 9.0 μM 2,4-D. Multiple shoots were produced from protoplast-derived callus after culture on MS medium containing 6.8 μM zeatin. After root induction on half-strength MS medium that lacked growth regulators, shoots were transferred to pots containing artificial soil mix.
34 citations
TL;DR: In this article, a statistical simulation and life prediction due to the high temperature fatigue crack growth process was performed and illustrated as output on a two-dimensional graphical display, using this information as input data and a condition for the connection and interactions of cracks.
Abstract: — Quantitative information, such as the initiation period, growth and coalescence behaviour, statistical distributions of crack length, density of cracks, distribution patterns and crack growth properties, were obtained from fatigue tests on type 304 stainless steel at 538°C in a previous study. Using this information as input data and a condition for the connection and interactions of cracks, a statistical simulation and life prediction due to the high temperature fatigue crack growth process was performed and illustrated as output on a two-dimensional graphical display.
29 citations
TL;DR: In this article, a series of iron carbonyl derivatives of 1,1′-bis(diphenylphosphino)ferrocene (BPPF) with Fe2(CO)9 and Fe3(CO).
28 citations
TL;DR: In this article, the authors examined the impact of changes in the variance of output prices on the bias and intra-firm diffusion rate of technological change, and found that a reduction in price variance will increase the rate of adoption and the intra-irm diffusion speed of yield-increasing technologies.
23 citations
TL;DR: In this article, C 3 H 8 was added in order to obtain stoichiometric β-SiC in the MTS + H 2 CVD system and the experiments were carried out by using a cold-wall reactor under atmospheric pressure in the temperature range 1100-1500°C.
Abstract: C 3 H 8 was added in order to obtain stoichiometric β-SiC in the MTS + H 2 CVD system. The experiments were carried out by using a cold-wall reactor under atmospheric pressure in the temperature range 1100–1500°C. XRD, Vickers microhardness tester and SEM were used in characterizing the stoichiometry and morphology. In the absence of C 3 H 8 the temperature required for the deposition of stoichiometric SiC was above 1500°C, otherwise excess Si was codeposited with SiC. With C 3 H 8 addition, however, stoichiometric SiC could be obtained even at temperatures as low as 1200°C and the preferred orientation was changed from (220) to (111). The microstructure and hardness value were related to the preferred orientation and stoichiometry of the coating layers, respectively.
TL;DR: In this paper, the structures of the products have been determined by single-crystal X-ray diffraction methods in the cubic space group Pm3m, and the extent of reaction depends upon experimental conditions.
TL;DR: In this paper, the inverse scattering formulation has been modified to be applicable in the spectral domain and it implies that enlargement of the discretized cell size is a key factor in regularizing the ill-posedness.
TL;DR: In this paper, a part flow control model for a type of flexible manufacturing system (FMS) called a dedicated flexible flow line (FFL) was developed and evaluated, where the focus of the approach is directed toward managing WIP buffers for each machine group queue.
Abstract: This research involves the development and evaluation of a part flow control model for a type of flexible manufacturing system (FMS) called a dedicated flexible flow line (FFL). In the FFL, all part types flow along the same path between successive machine groups. The specific objective of the part flow control model for the FFL is to minimize makespan for a given set of parts produced in a FFL near-term schedule, given fixed available buffer constraints. The control model developed in this research involved the repeated, real-time execution of a mathematical programming algorithm. The algorithm attempts to release the right mix of parts at the tight time to keep the FFL operating smoothly. The focus of the approach is directed toward managing WIP buffers for each machine group queue. The algorithm specifically incorporates stochastic disturbance factors such as machine failures. Through a limited number of simulation experiments, performance of the control model is shown to be superior to other parts releasing and control methods reported in the literature.
01 Jan 1992
TL;DR: In this paper, the structural modification of raw starch was modified by means of extrusion, and the direct synthesis of CD in a heterogeneous enzyme reaction system containing insoluble extruded starch was attempted.
Abstract: Cyclodextrin (CD) production has been mainly carried out in a homogeneous enzyme reaction system utilizing soluble liquefied starch (1,2). The shortcomings of above conventional CD production method were low CD yield and difficulties of separation and purification, due to formation of undesirable oligosaccharides (3). Direct production of CD from insoluble raw starch has distinct advantage of formation of high purity of CD without accumulation of undesirable oligosaccharides, which will facilitated purification of CDs (4,5). But raw starch exists as a compact crystalline structure, and the rate and yield of CD formation by cyclodextrin glucanotransferase (CGTase) is too low for industrial application. Therefore the structural modification of raw starch is required to increase the susceptibility to enzyme. In this work, the structre of raw starch was modified by means of extrusion, and the direct synthesis of CD in a heterogeneous enzyme reaction system containing insoluble extruded starch was attempted.
TL;DR: The DDY mouse is likely to be the most suitable experimental animal among the six strains of the mice tested and there are intraspecific variations in biologic incubation period, fertile period, and fecundity of C. sinensis.
Abstract: 여섯 계통의 근교계 마우스떠에 상흡충의 기생기간과 경시적 산란력을 근거로 하여 숙주 기생충 관계의 계통별 차이를 구명하기 위해 마우스찰 20개의 간흡충 피낭유충을 경구적으로 감염시켰다. 감염 후 간흡충의 충란이 처음 검출될 때까지의 기간은 DDY 마우스에서 평균 21.2일로 가장 짧았고, GPC 21.48, BALB/c 및 DS 23.2 5, ICR 및 nude 23.4일의 순이 었다. 총산란기간 역시 DDY 마우스에서 164일로 가장 길었으며, GPC 132R, BALB/c 97일, nude 37일, DS 32일 및 ICR 28일의 순이었다. DDY 및 GPC 마우스에서는 간흡충의 산란수가 비교적 높고 안정적이었으나 나머지 4계통의 마우스에서는 관찰기간 동안 불규칙하였다. 이상의 성적으로 미루어 보아 마우스의 계통에 따라 간흡충의 숙주 기생충 관계의 차리를 확인하였고 DDY 마우스가 6계통중 가장 호적숙주임을 알았다. 【In order to compare the intraspecific variation in host-parasite relationship of Clonorchis sinensis, six strains of inbred mice, ICR, DDY, GPC, BALB/c, nude and DS, were infected orally with 20 metacercariae of C. sinensis. The biologic incubation period of C. sinensis was the shortest in DDY mice, 21.2 days in average, followed by GPC 21.4, BALB/c and DS 23.2, ICR and nude 23.4 days, respectively. The fertile period of the cuke was also the longest in the DDY strain, 164 days on average, followed by GPC 132, BALB/c 97, nude 37, DS 32 and ICR 28 days. The egg-laying capacity of the cuke in DDY and GPC was relatively high and stable compared with the other four strains of mice. It was found that there are intraspecific variations in biologic incubation period, fertile period, and fecundity of C. sinensis. The DDY mouse is likely to be the most suitable experimental animal among the six strains of the mice tested. Key words: Mouse strain, Clonorchis sinensis, egg-laying capacity.】
TL;DR: In this article, the surface-enhanced Raman scattering (SERS) has been recognized as a powerful tool for investigating the vibrational structure of molecules, the requirement that the molecules under study should have appropriate functional groups to interact with the metal surface has been a major problem in applying the SERS effect to many chemical or biological systems.
Abstract: Although surface-enhanced Raman scattering (SERS) has been recognized as a powerful tool for investigating the vibrational structure of molecules, the requirement that the molecules under study should have appropriate functional groups to interact with the metal surface has been a major problem in applying the SERS effect to many chemical or biological systems. It is shown that the introduction of a surfactant such as cetyltrimethylammonium bromide in a silver sol results in a strong Raman signal enhancement of negatively charged water-soluble metallotetrakis(4-sulphonatophenyl)porphyrins. Without introducing CTAB into a silver sol, these porphyrin molecules did not show any colour change and consequently no SERS effect was observed. Such a surfactant-aided SERS effect will provide the possibility of applying SERS to new molecular systems.
TL;DR: The validity of the inversion scheme to regularization of the noise effects is conformed by showing that averaging the reconstructed profile over each cell with a suitable weighting function reduces the reconstruction error to a nearly negligible value.
Journal Article•
TL;DR: It is suggested that 1,25-(OH)2D3 and ascorbic acid may be involved in the control of cartilage growth and terminal differentiation.
Abstract: To clarify the role of vitamins D and C in chondrocyte hypertrophy of craniofacial cartilage, we have studied cultured chondrocytes from rabbit mandibular condylar cartilage (MCC), sphenooccipital synchondrosis (SOS) and nasal septal cartilage (NSC) under conditions in which these cells mature into hypertrophic chondrocytes In cultures of MCC- and SOS-chondrocytes, alkaline phosphatase (ALPase) activity started to increase on day 9 at confluence and the cessation of cell division, and reached a maximum on day 18 The degree of the increase of ALPase activity on day 18 was higher in MCC-chondrocytes than in SOS-chondrocytes ALPase activity was very low level in NSC- and CGC-chondrocytes Ascorbic acid induced a marked increase in ALPase activity in MCC-, SOS-, NSC- and CGC-chondrocytes The ALPase activities in MCC- and SOS-chondrocytes with 50 micrograms/ml ascorbic acid were 25-times those in its absence Those in NSC- and CGC-chondrocytes were 10 times and 20 times, respectively When chondrocytes were cultured with 10% charcoal-treated serum, ALPase activity decreased less than that in cultures with 10% normal serum in MCC-, SOS-, NSC- and CGC-chondrocytes Treatment of 1,25-(OH)2D3 for 9 days from days 4 to 13 in MCC-chondrocytes and for 14 days from days 4 to 18 in SOS-, NSC- and CGC-chondrocytes inhibited ALPase activity dose-dependently at the concentrations of 10(-12) M to 10(-8) M in MCC- chondrocytes, 10(-10) M to 10(-8) M in SOS- and CGC-chondrocytes, 10(-11) M to 10(-9) M in NSC-chondrocytes These findings suggest that 1,25-(OH)2D3 and ascorbic acid may be involved in the control of cartilage growth and terminal differentiation
TL;DR: In this paper, a Bayes estimator and a bootstrap estimator are proposed for two normcal populations with common known variance and also for normal population with common unknown variance.
Abstract: For ranking and selection problems, the true probabiIity of a correct selection P(CS) is unknown even if a selection is made under the indifference-zone approach. Thus to estimate the true P(CS) some Bayes estimators and a bootstrap estimator are proposed for two normcal populations with common known variance. Also a bootstrap estimator and a bootstrap confidence interval are proposed for normal populations with common unknown variance. Some comparisons between proposed estimators and some other known estimators are made via Monte Carlo simulations.
TL;DR: In this paper, it was suggested that the phenylsilylene was generated from the [3 → 2 + 1] cycloelimination of an intermediate of the 2-phenyloxasilacyclopropane (PhHSiOφCH2) which can arise from a possible intramolecular silylene insertion into the CH bond of the methoxy group in PhSiOMe.
TL;DR: In this paper, a theoretical analysis of an E-plane gap-coupled rectangular microstrip array antenna with one center-fed patch and several parasitic elements is presented, where the antenna characteristics such as radiation pattern and return loss are computed theoretically and compared with experimental results for illustrating the usefulness of this method.
Abstract: The purpose of this article is to present a theoretical method for analyzing an E-plane gap-coupled rectangular microstrip array antenna which consists of one center-fed patch and several parasitic elements by use of the transmission-line model and the equivalent circuit parameters for the capacitive gap between microstrip patch and the open end of the patch. Antenna characteristics such as radiation pattern and return loss are computed theoretically and compared with experimental results for illustrating the usefulness of this method.
TL;DR: In this article, the kinetics of hydrogen adsorption on a niobium surface were studied as a function of temperature and time, and the normalized surface fraction in terms of the initial sticking coefficients at a fixed hydrogen pressure was obtained.
TL;DR: In this article, the authors showed that the addition of 0.1 to 0.25 BaCO3 stabilizes the perovskite phase in PCN and the maximum dielectric constant appeared with x=0.1 in Pb1-xBax(Cd1/3Nb2/3)O3 system.
Abstract: Lead-cadmium-niobate ceramics Pb(Cd1/3Nb2/3)O3 are difficult to prepare because of the formation of a pyrochlore phase which is detrimental to the dielectric properties. The addition of 0.1 to 0.25 BaCO3 stabilizes the perovskite phase in PCN. Maximum dielectric constant appeared with x=0.1 in Pb1–xBax(Cd1/3Nb2/3)O3 system. Curie temperature of these system decreased with increasing amount of substituted Ba2+ ions (x).
01 Mar 1992
TL;DR: An approach to solve the stereo matching problem using the neural network with a new energy function derived not only to satisfy three constraints of similarity, smoothness, and uniqueness, but also to ensure Hopfield's convergence rules of symmetrical interconnection strength without self-feedback.
Abstract: In vision research, most problems can be modeled as minimizing an energy function. Particularly, stereo matching can be viewed as one of the optimization problems in which the constraints must be satisfied simultaneously. Neural networks have been demonstrated to be very effective in computing these problems. In this paper, an approach to solve the stereo matching problem using the neural network with a new energy function is presented. The new energy function is derived not only to satisfy three constraints of similarity, smoothness, and uniqueness, but also to ensure Hopfield's convergence rules of symmetrical interconnection strength without self-feedback. Experimental results shows good stereo matching for sparse random dot stereograms and real images.
01 Nov 1992
TL;DR: A modified IHS coordinate system is proposed to remedy the nonlinearity of the IHS system and is derived to linearize the relationship between the saturation and intensity.
Abstract: Color image enhancement is a technique which makes an image more vivid for human vision. Most affecting color elements for the image are intensity, contrast, and saturation. In handling these color elements with the conventional coordinates, their geometric form is important in view of valid gamut. Of them, IHS coordinate appropriately represents human color perception and it is easy to manipulate hue, intensity, and saturation of the image. The geometric form of this coordinate is, however, nonlinear, so that it is difficult to control the element values since they may exceed the valid gamut. In this paper, a modified IHS coordinate system is proposed to remedy the nonlinearity of the IHS system. The proposed coordinate is derived to linearize the relationship between the saturation and intensity. To improve the image quality, contrast is increased by maximizing the dynamic range of intensity, and saturation is normalized in full range of the intensity because the ratio between the changed saturation values should be maintained as the same ratio between original values. Hue is preserved to keep the characteristic property of the color image. This coordinate system is easy for enhancing color images and avoiding the gamut-overflow problem.
Patent•
16 Jun 1992TL;DR: A feed composition for breeding pigs containing about 70 to 90% by weight of an n-3 fatty acid source, about 10 to 20% of a carbohydrate source, and about 0.1 to 1.0% of an antioxidant for promoting a decrease in the level of cholesterol as mentioned in this paper.
Abstract: A feed composition for breeding pigs contains about 70 to 90% by weight of an n-3 fatty acid source, about 10 to 20% by weight of a carbohydrate source, about 0.1 to 1.0% by weight of an agent for promoting a decrease in the level of cholesterol, and about 0.1 to 1.0% of an antioxidant.