• The Pure and Applied Mathematics
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• v.3 no.1
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• pp.47-52
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• 1996

We consider the third order linear homogeneous differential equation L$_3$(y) = y(equation omitted) ＋ P($\chi$)y' ＋ Q($\chi$)y = 0 (E) P($\chi$) $\geq$ 0, Q($\chi$) ＞ 0 and P($\chi$)/Q($\chi$) is nondecreasing on [${\alpha}$, $\infty$) for some real number ${\alpha}$. (1) In this paper we discuss the distribution of zeros of solutions and a condition of oscillatory for equation (E).(omitted)

• Bulletin of the Korean Mathematical Society
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• v.56 no.4
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• pp.853-865
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• 2019

In this paper, we consider gradient estimates for positive solutions to the following nonlinear elliptic equation on a complete Riemannian manifold: $${\Delta}_Vu+cu^{\alpha}=0$$, where c, ${\alpha}$ are two real constants and $c{\neq}0$. By applying Bochner formula and the maximum principle, we obtain local gradient estimates for positive solutions of the above equation on complete Riemannian manifolds with Bakry-${\acute{E}}mery$ Ricci curvature bounded from below, which generalize some results of [8].

• Journal of Biosystems Engineering
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• v.28 no.2
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• pp.167-172
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• 2003

This study was performed to fabricate a batch-type SPR biosensing system using a thiolated E. coli antibody coupling, and to explore the feasibility of real-time detection of E. coii in a stagnant sample solution. In advance. “O” and “K” antigenic serotype E. coli antibodies were thiolated with sulfo-LC-SPDP and dithiothreitol, and immobilized by chemisorption in the gold surface of compact SPR sensors. When the SPR biosensor immobilized with E. coli antibody monitored a E. coli solution, it took 3 to 5 min to stabilize. The SPR biosensing system developed in this study was able to detect E. coli in the range above 10$^4$ CFU/mL at the 0.05 significant level. Also, the SPR biosensor had possibility to significantly detect E. coli in the range of 10$^2$ to 10$^4$ CFU/mL in E. coli solutions. Meanwhile, when the SPR biosensor immobilized with 5. coli antibody was cleaned with NaOH solutions, its ability to detect E. coli largely decreased due to wash-out of the immobilized antibody. In order to reuse the SPR sensor, it should be antibody-immobilized newly.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.1
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• pp.36-43
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• 2009

In this study, the impact of the covariance between the baselines on the network-based GPS positioning is analyzed. For the analysis, the multi-baseline solutions with properly modeled covariance between the baselines and the combined solutions from the single-baseline solutions are obtained, respectively. Then, the accuracies of both solutions are evaluated in terms of coordinate residuals, i.e., the differences between the positioning solutions and the published stations' coordinates. The results indicate that the positioning accuracy in static mode depends much on the geometry of GPS satellites rather than the proper modeling of covariance between the baselines. Also, slight but negligible improvement in positioning accuracy is observed in static solutions. Therefore, one may use combined solutions as an alternative to multi-baseline solutions for the network-based GPS positioning. However, multi-baseline solution with properly modeled covariance between the baselines is recommended to use especially for the applications to detect very small displacement, i.e., deformation of the building or bridge.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.2
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• pp.327-346
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• 2013

Researchers as well as network providers are increasingly interested in understanding how a network user's experience changes in relation to different quality of service (QoS) parameters, with many attempts being made to identify the general relationship between quality of experience (QoE) and QoS. Several relations in different function forms have been proposed. There are instances when this variety of proposed functions potentially results in one problem having completely dissimilar solutions at the same time. The question then is which function form is the one that can better explain this relationship. In this paper, three major existing quantitative relationships between QoE and QoS are investigated. After conducting a comprehensive comparative analysis between them, a new definition of QoE-QoS dependency appears. It then results in identifying a new mutual relationship between QoE and QoS. The newly proposed relationship improves the deficiency of previous QoE-QoS relationships along with solving the problem of diversity of simultaneous solutions for one problem.

• Toxicological Research
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• v.30 no.1
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• pp.13-18
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• 2014

Electronic cigarettes (e-cigarettes) are becoming increasingly popular worldwide and their cellular effects warrant further evaluation. In this study, we investigated the effects of an e-cigarette cartridge solution on allergen related asthmatic airway inflammation (AI) and airway hyperresponsiveness (AHR), when it is delivered by intratracheal route in mice. Asthmatic AI and AHR were induced by systemic sensitization to ovalbumin (OVA) followed by intratracheal, intraperitoneal, and aerosol allergen challenges in BALB/c mice. The cartridge solution of e-cigarette (containing 16 mg/ml nicotine) was diluted 50 times and $100{\mu}l$ of the diluted solution was intratracheally instilled to OVA-sensitized (OVA-S) mice two times a week for 10 weeks. Long-term e-cigarette inhalation elicited no remarkable changes in the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase enzymes in serum, however, increased infiltration of inflammatory cells including eosinophils, into airways from blood, aggravated the asthmatic AI and AHR, and stimulated the production of cytokines such as interleukin (IL)-4, IL-5 and IL-13, and OVA-specific IgE production. Our data suggest that the inhalation of e-cigarette solutions can function as an important factor to exacerbate the allergy-induced asthma symptoms. Further studies are needed to address the effects of e-cigarette solutions on human health.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.4 no.1
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• pp.40-44
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• 2004

In this paper we study the existence and uniqueness of fuzzy solutions for the nonlinear fuzzy integro-differential equations on $E^{n}_{N}$ by using the concept of fuzzy number of dimension n whose values are normal, convex, upper semicontinuous and compactly supported surface in $E^{n}_{N}$. $E^{n}_{N}$ be the set of all fuzzy numbers in $R^{n}$ with edges having bases parallel to axis $x_1$, $x_2$, …, $x_n$.

• Journal of the Korean Chemical Society
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• v.18 no.2
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• pp.110-116
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• 1974

Reduction of chromate ion at the Pt-electrode was investigated in neutral unbuffered solutions, in buffered solutions of pH between 8 and 10, and in strongly alkaline medium. In buffered solutions of pH between 8 and 10, the number of electrons transfered in the reduction of chromate ion increased progressively with increasing pH. When chromate ion was reduced in 0.2 N sodium hydroxide medium the following mechanism was suggested: $CrO_4^=+H_2O+2e{\rightarrow}CrO_3^=+2OH^-,\;CrO_3^=3H_2O+e{\rightarrow}Cr(OH)_3+3OH^-$ When tetramethylammonium hydroxide (pH=13.5) was used as the supporting electrolyte, a second wave indicated strong adsorption. In unbuffered solutions of 0.1 N potassium chloride the linear sweep voltammogram consists of three or four distinct waves depending on the initial voltage and the voltage sweep rates, but the first wave was difficult to explain as a diffusion controlled wave.

• Information Systems Review
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• v.4 no.2
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• pp.155-168
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• 2002

This paper examines whether the functions of eCRM solutions affect the site visit and purchase by customers. The functions of eCRM solutions are extracted and classified into three categories of c-marketing, e-sales, and e-service. E-marketing includes campaign/event marketing, e-mail marketing, and questionnaire marketing; e-sales consists of recommendation system and incentive/discount promotion.; e-service is composed of e-mail call center and web call center. From the online survey, 146 responses are collected and analyzed. The analysis shows that the level of experience in campaign/event marketing, e-mail marketing, e-mail call center, and web call center significantly affect the website visit by customers and that the level of experience in all eCRM functions except e-mail marketing significantly affect the purchase by customers. The effects of those functions in eCRM on the website visit are moderate, while the effects of the functions on the purchase are low. The results from this study imply that eCRM needs to strengthen the effect on the purchase with more thorough analysis of the customer profile.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10b
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• pp.772-776
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• 1988

In quantized control systems, the control values can take only given discrete (e.g. integer) values. In case of dealing with the control problem on the discrete-time, final-stage fixed, quantized control systems with multidimensional performance functions, the first thing, new definition on noninferior solutions in these systems is necessary because of their discreteness in state variables, and the efficient search for those solutions at final-stage is unavoidable for seeking their discrete-time optimal controls to these systems. In this paper, to the quantized control problem given by the formulation of Halkin-typed linear control systems with two performance functions, a new definition on noninferior solutions of this system control problem and a heuristic effective search on these noninferior solutions are stated. By use of these concepts, two definitions on noninferior solutions and the algorithm consisted of 8 steps and attained by geometric approaches are given. And a numerical example using the present algorithm is shown.