Showing papers by "Sungkyunkwan University published in 1995"
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TL;DR: In this paper, the economic theory of predation was incorporated into the theory of economic growth, and a dynamic general-equilibrium model of the interaction between two dynasties, one of which is a potential predator and the other is its prey, was proposed.
Abstract: This paper incorporates the economic theory of predation into the theory of economic growth. The analytical framework is a dynamic general-equilibrium model of the interaction between two dynasties, one of which is a potential predator and the other is its prey. Each generation of each dynasty has to decide how to allocate its endowment of inherited wealth not only to consumption and productive capital, as in standard growth models, but also to either defensive fortifications or offensive weapons. Productive capital forms a basis for accumulation of wealth but in each generation predation can cause both the destruction of wealth and a redistribution of wealth from the prey dynasty to the predator dynasty. We find that, if the current wealth of the potential predator dynasty is small relative to the current wealth of the prey dynasty, then the current generation of the prey dynasty chooses to tolerate predation rather than to deter predation. We also find that over generations the security of the prey dynasty's property and the rate of accumulation of the it's productive capital both steadily decrease, while the inherited wealth of the predator dynasty grows relative to that of the prey dynasty. Eventually a generation of the prey dynasty will find that with predation its property is so insecure it is better off increasing its defensive fortifications to deter predation.Importantly, the relation between the security of the prey dynasty's property and its accumulation of productive capital, is neither continuous nor monotonic. Generations of the prey dynasty that choose to deter predation even though their property is secure accumulate productive capital more slowly than the preceding generations that tolerated predation. Even if deterrence becomes preferable for the prey dynasty than predation, deterrence is costly.
147 citations
TL;DR: Although CT findings of pulmonary tuberculosis and MAI are similar, interlobular septal thickening is more common in patients with tuberculosis and bronchiectasis is moreCommon and more extensive in Patients with MAI.
Abstract: PURPOSE: To compare the computed tomographic (CT) findings of tuberculosis and Mycobacterium avium-intracellulare (MAI) infection in immunocompetent patients. MATERIALS AND METHODS: Seventy-seven consecutive immunocompetent patients with culture-proved pulmonary mycobacterial infection (45 with pulmonary tuberculosis, 32 with MAI) underwent thin-section CT. CT scans were randomized and reviewed by two observers; decisions were reached by consensus. RESULTS: Micronodules, consolidation, and cavity formation in the lung were seen with similar frequency in pulmonary tuberculosis and MAI cases. Twenty-three patients (51%) with tuberculosis and four patients (12%) with MAI had interlobular septal thickening (P < .001). Twelve patients (27%) with tuberculosis and 30 patients (94%) with MAI had bronchiectasis (P < .001). Bronchiectasis was seen in a mean of 4.6 +/- 1.8 and 1.8 +/- 1.6 lobes (+/- standard deviation) in each patient with MAI and with tuberculosis, respectively (P < .01). CONCLUSION: Although CT fi...
118 citations
TL;DR: The results show a strong increase of the directed flow with fragment mass at all energies measured, and it is found that neither the ``soft`` nor the ``hard`` equation of state can describe the data over the entire range of beam energies.
Abstract: Exclusive measurements have been made of Au+Au reactions with beam energies ranging from 0.25{ital A} to 1.15{ital A} GeV. We present measurements of directed collective flow averaged over all light fragments with masses up to alphas, as well as separate measurements for protons, deuterons, tritons, {sup 3}He, {sup 4}He, and Li. The results show a strong increase of the directed flow with fragment mass at all energies measured. Experimental results are compared with a quantum molecular dynamics model. We find that neither the ``soft`` nor the ``hard`` equation of state can describe the data over the entire range of beam energies.
77 citations
TL;DR: In this paper, the W boson mass in W − ev decays was measured using 1 fb^-1 of data collected with the D0 detector during Run II of the Fermilab Tevatron collider.
Abstract: We present a measurement of the W boson mass in W -> ev decays using 1 fb^-1 of data collected with the D0 detector during Run II of the Fermilab Tevatron collider. With a sample of 499830 W -> ev candidate events, we measure M_W = 80.401 +- 0.043 GeV. This is the most precise measurement from a single experiment.
75 citations
TL;DR: In this article, the electrochemical properties and morphologies of platinum thin films on the conductive ceramics TiO and Ebonex (Ti4O7) have been examined.
46 citations
TL;DR: CT findings in paraquat poisoning of the lung begin with ground-glass attenuation, which leads to consolidation with bronchiectasis or irregular lines, and this pattern was bilateral and diffuse in distribution.
Abstract: PURPOSE: To describe thin-section computed tomographic (CT) findings in paraquat poisoning of the lung. MATERIALS AND METHODS: Thin-section CT scans of the lungs in 16 patients with paraquat poisoning were reviewed. The patients were nine male and seven female persons whose ages ranged from 16 to 74 years (mean, 29 years). Follow-up CT scans were available for seven patients. RESULTS: The most common pattern on initial scans was ground-glass attenuation, present alone or as part of a mixed pattern in 13 patients. It was bilateral and diffuse in distribution. Consolidation was present in six patients, irregular lines in three, and nodules in two patients. On follow-up scans, the ground-glass attenuation had changed to consolidation with bronchiectasis. Additional irregular lines and traction bronchiectasis also were observed. CONCLUSION: CT findings in paraquat poisoning of the lung begin with ground-glass attenuation, which leads to consolidation with bronchiectasis or irregular lines.
41 citations
TL;DR: In this article, the initial interface and silicide formation induced by Mg adsorption on the Si(111)7×7 surface have been studied using low-energy electron diffraction, x-ray photoelectron spectroscopy, and synchrotron radiation photo-electron analysis.
Abstract: The initial interface and silicide formation induced by Mg adsorption on the Si(111)7×7 surface have been studied using low‐energy electron diffraction, x‐ray photoelectron spectroscopy, and synchrotron radiation photoelectron spectroscopy. At room temperature, it is found that Mg atoms are preferably adsorbed on top sites of Si adatoms and rest atoms on the Si(111)7×7 surface and with increasing of Mg deposition, a Mg2Si epitaxial layer is formed and the surface structure transforms from the diffuse (1×1) phase into the (2/3√3×2/3√3)R30°. After growing up to a critical thickness, the Mg film grew in a disordered phase on the epitaxial layer. The Fermi level of the Mg2Si film is positioned at 0.51±0.05 eV above the valence band maximum. On the other hand, at 300 °C the Mg2Si epitaxial layer was formed in the (1×1) phase on the Si(111)7×7 and grew up to a critical thickness in the initial stage. For the successive evaporation, the Mg film grew in a disordered phase on the Mg2Si(111)1×1 surface.
28 citations
TL;DR: Water extraction with subsequent picric acid treatment and solvent washing (ethyl acetate and diethyl ether) was employed for the rapid isolation of free amino acids from non-aqueous food samples, and eleven non-protein amino acids were tentatively identified.
28 citations
TL;DR: In this article, failure-censored accelerated life tests are used to design sampling plans with equal expected test times at high and low test stresses which satisfy the producer's and consumer's risk requirements and minimize the asymptotic variance of the test statistic used to decide lot acceptability.
28 citations
06 Nov 1995
TL;DR: In this paper, an efficient trajectory generation technique to generate smooth velocity profiles for fast motion is proposed, where the velocity after the acceleration is determined for a given movement and then a smooth velocity profile is generated by using some pre-determined coefficients.
Abstract: To make fast motion with minimal vibration in industrial robots, it is necessary to generate smooth trajectories efficiently. Some trajectory planning techniques using software or hardware methods have been proposed to generate smooth velocity profiles. The problem in these techniques is that the time required to generate velocity profiles is too long or the order of velocity profiles is fixed. In this paper, an efficient trajectory generation technique to generate smooth velocity profiles for fast motion is proposed. The velocity after the acceleration is determined for a given movement and then a smooth velocity profile is generated by using some pre-determined coefficients. The comparison of the proposed technique and the existing techniques show that the proposed technique is more efficient and is able to reduce the moving time of robots.
22 citations
TL;DR: In this article, a high-speed mesa type SAGCM avalanche photodiodes for 2.5 Gb s-1 optical receivers have been realized for the first time.
Abstract: High-speed mesa type SAGCM avalanche photodiodes for 2.5 Gb s-1 optical receivers have been realized for the first time. The device is designed by dimensional analysis based on the electric field distribution in a multiplication layer and a charge plate layer. Very low dark current and high gain are obtained with an active region of 30 μm diameter. From the 1.55 μm wavelength 2.488 Gb s-1 transmission experiment, sensitivity of-33.6 dBm is measured using pseudorandom (223–1) NRZ patterns.
TL;DR: In this paper, the heat transfer characteristics of a low temperature latent heat storage system have been determined for the circular finned and unfinned tubes using sodium acetate trihydrate as a phase change material (PCM).
Abstract: Heat transfer characteristics of a low temperature latent heat storage system have been determined for the circular finned and unfinned tubes using sodium acetate trihydrate as a phase change material (PCM). In the heat storage stage (melting process). the PCM heat transfer coefficient in the unfinned-tube system showed good agreement with the calculated value by the heat conduction equation. The heat transfer between the tube wall and the PCM was not enhanced by the fins in the thin-finned-tube system, whereas 2 times higher heat-transfer coefficient for the thick-finned-tube system over the unfinned-tube system was obtained. The experimentally determined heattransfer coefficients in the unfinned-tube and thick-finned-tube systems are in the ranges of 40–170 and 80–320 W/m2-k, respectively. The amount of heat storage for three systems has been correlated in terms of Fourier, Stefan and Reynolds numbers. The thermal performance of heat storage systems are found to be strongly dependent on the
TL;DR: A Tc-99m MDP bone scan showed faint renal uptake, as well as diffuse high skeletal uptake, particularly in the spine, demonstrating that the metabolic bone disease associated with Fanconi syndrome can be one of the causes of poor renal visualization on a bone scan.
Abstract: The authors present a patient with Fanconi syndrome who demonstrated poor renal uptake of Tc-99m DMSA and high urinary concentration of the tracer. Tc-99m DTPA imaging was normal and the creatinine clearance was only minimally decreased. These findings suggest that Tc-99m DMSA may be accumulated in the kidney by glomerular filtration and subsequent tubular reabsorption. A Tc-99m MDP bone scan showed faint renal uptake, as well as diffuse high skeletal uptake, particularly in the spine, demonstrating that the metabolic bone disease associated with Fanconi syndrome can be one of the causes of poor renal visualization on a bone scan.
TL;DR: In this paper, the origin of low carrier concentration in USb is discussed based on the first observation of dHvA oscillations and it is also unambiguously demonstrated that the unconventional heavy Fermion state of Yb4As3 is intrinsic and not due to impurities.
Abstract: Recent progress in studies on low carrier concentration systems of magnetically ordered and non-magnetic heavy Fermion metals are discussed. Successive steps in the high field magnetisation, the magnetic structure, and the influence of high pressure are reported and the relation with the observed Fermi surface for CeP is discussed. The origin of the low carrier concentration in USb is also discussed based on the first observation of dHvA oscillations. It is also unambiguously demonstrated that the unconventional heavy Fermion state of Yb4As3 is intrinsic and not due to impurities.
TL;DR: Post-column fluorescence HPLC was developed for nanogram level salmon calcitonin (sCT) assay for the in vitro evaluation of sCT formulations and successfully applied for the quantitation of s CT from biodegradable microspheres, injection and nasal spray formulations.
TL;DR: For the determination of salmon calcitonin and its degradation products in biological samples, a reversed-phase HPLC method with column switching and flow-through radioisotope detection has been developed using high specific activity [125I]salmon calcitonIn.
TL;DR: In this paper, the L-head with or without squish area is selected to study the turbulent flow as varying various factors in a combustion chamber of a spark ignition engine, the turbulent as varying flow on the piston speed, inlet flow velocity, and squish velocity are measured by using hot wire anemometer.
Abstract: The turbulent flow in a spark ignition engine plays an important role in determining its combustion characteristics and thermal efficiency. In order to analyse the combustion process, the turbulent flow and its turbulence intensity must be studied. To study the turbulent flow as varying various factors in a combustion chamber of a spark ignition engine, the L-head with or without squish area are selected. The turbulent as varying flow on the piston speed, inlet flow velocity, and squish velocity are measured by using hot wire anemometer. To examine the characteristics of turbulent flow, the ensemble averaged mean velocity, turbulence intensity, turbulence intensity decrease ratio, production rate of turbulence intensity, production coefficient of turbulence intensity are analysied.
TL;DR: Two different derivatives of novel nonprotein amino acids in Gymnocladus dioicus seeds are prepared for gas chromatographic and mass spectrometric analysis, enabling confirmation of molecular weight and existence of functional groups containing active protons.
Abstract: Two different derivatives of novel nonprotein amino acids in Gymnocladus dioicus seeds are prepared for gas chromatographic (GC) and mass spectrometric (MS) analysis. The interfering components in a water extract of the seeds are removed by picric acid treatment and multistep washing with organic solvents followed by N(O,S)-isobutyloxycarbonylation combined with solid-phase extraction. The resulting N(O,S)-isobutyloxycarbonyl (isoBOC) amino acids are then converted to either tert-butyldimethylsilyl (TBDMS) or trimethylsilyl (TMS) derivatives, which are analyzed by dual capillary column GC and GC-MS. The characteristic ions in the mass spectra of N(O,S)-isoBOC TBDMS and N(O,S)-isoBOC TMS derivatives enable confirmation of molecular weight and existence of functional groups containing active protons. Temperature programmed retention index sets measured on DB-5 and DB-17 capillary columns (JW Folsom, CA) are useful for distinguishing among structural isomers. gamma-Methylglutamic acid, diastereoisomers of 3-hydroxy-4-methylglutamic acid, cis and trans isomers of 5-hydroxypipecolic acid, and some free protein amino acids are identified in Gymnocladus dioicus seeds.
TL;DR: Stability of pneumococcus gene library in cosmid vector and pACYC184 was examined and the instability problems seemed to be resolved when transcription terminator plasmid was employed forneumococcus library construction.
Abstract: S. pneumoniae (pneumococcus) gene cloning and library construction inE. coli multicopy plasmid has been hampered, in part, by instability problems. In this study, stability of pneumococcus gene library in cosmid vector and pACYC184 was examined. Pneumococcus library in the cosmid vector pHC79 was extremely unstable that most of the recombinant clones were degenerated rapidly. Only 2 out of 849 clones were stable and had appropriate insert size. Pneumococcus library in pACYC184 was also so unstable that the pneumococcal insert and/or part of the vector were deleted. However, the instability problems seemed to be resolved when transcription terminator plasmid was employed for pneumococcus library construction.
01 Oct 1995
TL;DR: The results on the time course of CCK-PZ-induced citrulline formation and rise of cGMP level indicate that NO synthase and guanylate cyclase are activated within the first seconds of stimulation, which confirms the conclusion that NO mediates the response to CCK -PZ by cG MP.
Abstract: In pancreatic cells, NO formation is associated with increased levels of cGMP and endocrine/ exocrine secretion. In the present study, the role of NO in the regulation of exocrine secretion was investigated in rat pancreatic tissues. Treatment of rat pancreatic tissue with cholecystokinin-pancreozymin (CCK-PZ) resulted in an significant increase in arginine conversion to citrulline, the amount of nitrite/nitrate, the release of amylase, and the level of cGMP. Furthermore, CCK-PZ-stimulated increase of amylase release and conversion of arginine to citrulline transformation were counteracted by the inhibitor of NO synthase, NG-nitro-L-arginine methyl ester. The results on the time course of CCK-PZ-induced citrulline formation and rise of cGMP level indicate that NO synthase and guanylate cyclase are activated within the first seconds of stimulation. The kinetics of citrulline accumulation correlate well with those of cGMP rise, which further confirms the conclusion that NO mediates the response to CCK-PZ by cGMP.
TL;DR: In this paper, the morphology control of poly(ethyl acrylate)/poly(methyl methacrylate) (PMMA) semi-interpenetrating polymer networks (IPNs) has been attempted either by changing reaction temperature or by adding the third component at the initial stage of phase separation.
Abstract: In this article the morphology control of poly(ethyl acrylate)/poly(methyl methacrylate) (PMMA) semi-interpenetrating polymer networks (IPNs) has been attempted either by changing reaction temperature or by adding the third component at the initial stage of phase separation. The morphological variation was followed via dynamic mechanical behavior and electron microscopy. It was found that raising the polymerization temperature of PMMA or adding linear PMMA to the initial mixture facilitates phase separation during the semi-IPNs formation process. However, the phase separation was further induced by annealing, which indicates that kinetically controlled morphology was not at its equilibrium state. © 1995 John Wiley & Sons, Inc.
TL;DR: None of the transformation-deficient mutants were sensitive to DNA damage suggesting that competence is not involved in DNA repair, and also DNA uptake and recombination gene might be related to DNA repair function.
Abstract: Seventeen transformation-deficient mutants ofStreptococcus pneumoniae, which are defective in competence induction(com−), DNA uptake(ent−) or recombination(rec−), were investigated to determine sensitivity to ethylmethane sulfonate(EMS), methylmethane sulfonate(MMS), UV and mitomycin C. In ethylmethane sulfonate assay, the viability of mostcom, rec andent− mutants was decreased about 2–10 times and the viability ofent-9 andent-13 mutant was decreased about 33 and 25 times, respectively. On the other hand only half of the transformation-deficient mutants tested was sensitive to methylmethane sulfonate about 2 times and ent-12 mutant was sensitive to 2.0% MMS about 8 times. After UV and mitomycin C treatment, most of the mutants are not sensitive to UV and mitomycin C, although the viability of some transformation-deficient mutants was decreased slightly. Especially none of thecom− mutants were sensitive to DNA damage suggesting that competence is not involved in DNA repair. Also DNA uptake and recombination gene might be related to DNA repair function.
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TL;DR: In this article, the authors investigate whether the stock market response to discretionary accruals varies depending both on the probability of managers receiving bonuses and the likelihood of firms violating debt contract constraints.
Abstract: In this paper, I investigate whether the stock market response to discretionary accruals varies depending both on the probability of managers receiving bonuses and the likelihood of firms violating debt contract constraints. I provide evidence that the stock market response to discretionary accruals is negative for the bonus maximization incentive, while it is significantly positive for the leverage reduction incentive. Also, I obtain a negative accrual response coefficient for observations with high bonus sensitivity and low leverage, and a positive accrual response coefficient for observations with low bonus sensitivity and high leverage. This result suggests that the stock market penalizes a manager's behavior to maximize bonuses, whereas it rewards his/her behavior to reduce the potential violation of debt contracts.
TL;DR: Biodegradability and tissue distribution of microspheres were examined by analyzing the amount of magnetite in the micro spheres recollected from mice organs after specific time interval and showed that GEG microsphere of high content of PEO was degraded more rapidly than those of low content ofPEO in the mice organs.
Abstract: Biodegradability of poly(γ-benzyl L-glutamate)/poly(ethylene oxide)/poly(γ-benzyl L-glutamate) block copolymer (GEG) having different content of poly(ethylene oxide) (PEO) were examined using magnetite as a tracer in mice. GEG microspheres containing magnetite were injected into mice through tail vein. Biodegradability and tissue distribution of microspheres were examined by analyzing the amount of magnetite in the microspheres recollected from mice organs after specific time interval. The results showed that GEG microsphere of high content of PEO was degraded more rapidly than those of low content of PEO in the mice organs.
TL;DR: CUIDE (Case-based UI Development Environment) is proposed in order to support UI development by end users, who have never developed any UI, and utilizes the casebase of design and the case base of parts to make up for their lack of knowledge and experience of UI development.
Abstract: To cope with individual requirements of user interface (UI) from various classes of users, it is desirable to have UI development support environment which allows end users to develop UIs without designer's helps. The support of conventional methods and tools, however, focuses on expert of UI development. In this paper, we propose a UI development environment for end users, named CUIDE (Case-based UI Development Environment) in order to support UI development by end users, who have never developed any UI. CUIDE utilizes the case base of design and the case base of parts to make up for their lack of knowledge and experience of UI development.
30 May 1995
TL;DR: In this article, the influence of the number of spark plug, spark times and spark intervals on discharge pattern of spark energy, ignitability and combustion characteristics were evaluated by visualizing the flame propagation.
Abstract: In order to establish the ignition system for lean burn, the influence of the number of spark plug, spark times and spark intervals on discharge pattern of spark energy, ignitability and combustion characteristics were evaluated. By visualizing the flame propagation with the number of spark plug, heat release was related with flame area, heat loss related with contact wall area by burned gas, combustion duration related with maximum flame travel distance respectively. It showed that, ignitability remarkably increases with the case of MSCDI than with the case of single spark and the lean limit extended fuel/air equivalence ratio by 0.1, the increase of magnitude and lasting time of capacity component and inductance component was multi spark discharge in a row.