• Journal of Biosystems Engineering
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• v.28 no.4
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• pp.335-342
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• 2003

A simple disposable thick-film potentiometric strip has been developed and evaluated for hydroponics application. The strip consisted of low ion-selective electrodes (ISE) fabricated by screen-printing technology. The electrochemical responses of ion sensors for nitrate, ammonium, potassium, and magnesium were measured with specially designed 16-channel low voltage signal transducers. The analytical characteristics of the sensors were comparable with those of conventional ISE sensors. The thick-film sensors exhibit linear relationships over five concentration decades. The concentration of N $O_3$ - ion in standard solution can be determined by direct potentiometric measurements without any conditioning before measurements. However, measurement of $K^{+}$, N $H_4$$^{+}$, and $Mg^{2+}$ ionic concentrations in nutrient solutions seems not feasible.

• Analytical Science and Technology
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• v.8 no.4
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• pp.457-460
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• 1995

A new hollow fiber filled with the lower refractive index liquid as core constructs a liquid core optical fiber(LCOF). The LCOF have been used as colorimetric cell to determine elements Cr and Cu in the presence of 70%- 50% ethanol or 50% dioxane aqueous solution, based on colored complex of Chromium(VI) with Diphenycarbazid(DPC) and copper with Chromaurd S(CAS) respectively. The sensitivity (1/ng/ml) of calibration curve of Cr and Cu are 0.052, 0.017 over the range 0 - 25, 0 - 24(ng/ml) respectively. The Cr in the animal gum and Nation Standard of China are determined with recoveries of 94 - 102%.

• Korean Journal of Construction Engineering and Management
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• v.8 no.6
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• pp.235-245
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• 2007

This research study presents the development and application of an Elitist Genetic Algorithm (Elitist GA) for solving the resource-constrained project scheduling problem, which is one of the most challenging problems in construction engineering. Main features of the developed algorithm are that the elitist roulette selection operator is developed to preserve the best individual solution for the next generation so as to obtain the improved solution, and that parallel schedule generation scheme is used to generate a feasible solution to the problem. The experimental results on standard problem sets indicate that the proposed algorithm not only produces reasonably good solutions to the problems over the heuristic method and other GA, but also can find the optimal and/or near optimal solutions for the large-sized problems with multiple resources within a reasonable amount of time that will be applicable to the construction industry. This paper will help researchers and/or practitioners in the construction project scheduling software area with alternative means to find the optimal schedules by utilizing the advantages of the Elitist GA.

• Preventive Nutrition and Food Science
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• v.4 no.2
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• pp.85-87
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• 1999

A simple and rapid method to estimate the viscosity of chitosan using laboratory pipettes was developed. The voscosities of nine different chitosan samples, prepared ini 1 % acetic acid at a 1% concentration , were measured with a standard viscometer. Prior to measurement of flow time of 1% chitosan solution with a pipette, twelve pipettes were assorted into three groups with flow times of 4, 5 and 6 sec after measuring passage of 9 ml of 1% acetic acid througth a 10 ml pipette. With each group of pipettes. flow time of 1% chitosan solution was determined by measuring the delivery time of 5 ml of the 10ml solution through a 10 ml pipette. Results of regression analyses revealed high linear relationship(R2=0.9812, 0.9663, and 0.9754) between viscosities calculated with a viscometer and flow times measured with 4, 5 or 6 sec group pipettes. The viscosity of chitosan could be readily and accurately estimated from these linear regression equation by measuring flow times based on pipette delivery.

• Journal of the Korean Chemical Society
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• v.8 no.3
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• pp.109-112
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• 1964

A volumetric method of the determination of calcium carbonate and calcium fluoride in fluorspar concentrate is described. The carbonate is converted into solution by treatment of the sample in HNO$_3$-acetone (l% by volume) mixture, and the fluoride by treating the residue with H$_3BO_3$-HCl mixture. The calcium in the solution is determined volumetrically using EDTA standard solution. The selective dissolution of calcium carbonate by HNO$_3$-acetone mixture is superior to Bidtel's acetic method and little correction for the dissolution of calcium fluoride is needed. Triethanolamine is found to be superior to KCN in masking heavy metal ions.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1996.04a
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• pp.47-53
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• 1996

An enhanced solution recovery method for recovering accurate derivatives such as moments, or shears, from finite element solutions for $C^{0}$ beam and plate is presented. In the enhanced method, the square of the residuals in the equilibrium equations is included. Results are compared with those of standard Zienkiewicz-Zhu methods. Numerical examples show that in the global projection, the enhanced technique improves the accuracy of projected solution significantly. In the local projection, the enhanced method circumvents the numerical ill-conditioning which occurs in some meshes, and usually recovers derivatives with better accuracy.y.

• Journal of the Korean Chemical Society
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• v.5 no.1
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• pp.76-79
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• 1961

The nickel has been separated and precipitated with dimethylglyoxime in the usual manner and dissolved the precipitates with hydrochloric acid. To the nickel solution, 0.2g of Murexide as an indicator and 5 ml of 20 percent tri-ethanol amine solution were added and titrated with a standard solution of EDTA. At the end point the color changes from yellow to deep purple. In this paper, the purpose is that conditions for titration and for separation from the interfering substances were investigated and a suitable procedure was found and applied on the determination of nickel in Korean nickel ores.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.9
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• pp.697-700
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• 2011

Thin-film transistors(TFTs) with magnesium zinc tin oxide(MZTO) channel layer are fabricated by solution-process. The threshold voltage (Vth) shifted toward positive directly with increasing Mg contents in MZTO system. Because the Mg has a lower standard electrode potential (SEP) than Sn, Zn, thus degenerate the oxygen vacancy ($V_O$). As a result, the Mg act as carrier suppressor and oxygen binder in the MZTO as well as a Vth controller.

• East Asian mathematical journal
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• v.38 no.5
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• pp.603-610
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• 2022

In [6, 7] they introduced a new finite element method for accurate numerical solutions of Poisson equations with corner singularities. They consider the Poisson equations with homogeneous boundary conditions, compute the finite element solutions using standard FEM and use the extraction formula to compute the stress intensity factor(s), then they posed new PDE with a regular solution by imposing the nonhomogeneous boundary condition using the computed stress intensity factor(s), which converges with optimal speed. From the solution they could get an accurate solution just by adding the singular part. They considered a partial differential equation with the input function f ∈ L²(Ω). In this paper we consider a PDE with the input function f ∈ H¹(Ω) and find the corresponding singular and dual singular functions. We also induce the corresponding extraction formula which are the basic element for the approach.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.739-748
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• 2007

The objective of this research study is to develop the permutation-based genetic algorithm for solving the resource-constrained project scheduling problem in construction engineering by incorporating elitism into genetic algorithm. A key aspect of the algorithm was the development of the elitist roulette selection operator to preserve the best individual solution for the next generation so the improved solution can be obtained. Another notable characteristic is the application of the parallel schedule generation scheme to generate a feasible solution to the problem. Case studies with a standard test problem were presented to demonstrate the performance and accuracy of the algorithm. The computational results indicate that the proposed algorithm produces reasonably good solutions for the resource-constrained project scheduling problem.