• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.4
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• pp.23-30
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• 1999

The thermal decomposition of phase stabilized ammonium nitrate(PSAN) was studied by means of thermogravimetric analysis(TGA). In this study, potassium nitrate and zinc oxide were used as the phase stabilizers in the range of contents from 0 wt.% to 8 wt.%. The kinetics and mechanism for the decomposition were evaluated using integral methods. It was found that the thermal kinetic parameters such as activation energy(I) and frequency factor(A) increase with the increase of the stabilizer contents, and the mechanism of decomposition also changes.

• Journal of the Korean Operations Research and Management Science Society
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• v.18 no.3
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• pp.129-149
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• 1993

The high level of activity in the development and maintenance of computer software makes the scheduling of software projects an importnat factor in reducing operating costs and increasing competitiveness. Software activity is labor intensive. Scheduling management of hours of software work is complicated by ther interdependencies between the segments of work, and the uncertainties of the work itself. This paper discusses issues of scheduling in software engineering management, and presents a modular decomposition model for software project scheduling, taking advantage of the facility for decomposition of a software project into relatively independent work segment modules. Modular decomposition makes it possible to treat scheduling as clustering and sequencing in the context of integer programming. A heuristic algorithm for the model is presented with some computational experiments.

• Journal of Environmental Science International
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• v.13 no.1
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• pp.69-77
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• 2004

In this study, sulfate reduction reaction was used to increase the decomposition of organics, which is the most critical factor for the stabilization of a landfill site. Composite of sewage sludge, papers, and incineration ashes was used in the column. The experimental results indicated that out of 10 reactors, the reactors 3, 4, 8. and 9 showed higher organics (i.e., TOC) removal rate than that in the absence of sulfate. The organics removal rates (K) in R3 and R9 were 8.65e$\^$-4/d and 3.82e$\^$-4//d, respectively. The times to reach 10％ of initial concentrations in R3 and R9 was 7.3 and 16.5 years, respectively, showing faster organics decomposition rates in these reactors.

• Korean Journal of Optics and Photonics
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• v.6 no.3
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• pp.178-187
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• 1995

The method that determines the appropriate damping factor is studied for a lens design. When suitable damping factor is applied to the additive damped least-squares (DLS) method, the convergence and the stability of the optimization process are examined in a triplet-type photographic lens design. We calculate eigenvalues of the product of the Jacobian matrix of error functions by using the singular value decomposition (SVD) method. We adopt the median of eigenvalues as an appropriate damping factor. The convergence and the stability of the optimization process are improved by choosing the adequate damping factor for the optimization of a photographic lens. It is known that the numerical inaccuracy in the calculation of normal equation is overcome by using the orthogonal transformations of the Jacobian matrix. Therefore, a combination of the method for setting a proper damping factor and the orthogonal transformations of the Jacobian matrix is good for application to the design of an aspheric lens with high-order terms. terms.

• Journal of Ecology and Environment
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• v.44 no.2
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• pp.81-89
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• 2020

In the forest ecosystems, litterfall is an important component of the nutrient cycle that regulates the accumulation of soil organic matter (SOM), the input and output of the nutrients, nutrient replenishment, biodiversity conservation, and other ecosystem functions. Therefore, a profound understanding of the major processes (litterfall production and its decomposition rate) in the cycle is vital for sustainable forest management (SFM). Despite these facts, there is still a limited knowledge in tropical forest ecosystems, and further researches are highly needed. This shortfall of research-based knowledge, especially in tropical forest ecosystems, may be a contributing factor to the lack of understanding of the role of plant litter in the forest ecosystem function for sustainable forest management, particularly in the tropical forest landscapes. Therefore, in this paper, I review the role of plant litter in tropical forest ecosystems with the aims of assessing the importance of plant litter in forest ecosystems for the biogeochemical cycle. Then, the major factors that affect the plant litter production and decomposition were identified, which could direct and contribute to future research. The small set of studies reviewed in this paper demonstrated the potential of plant litter to improve the biogeochemical cycle and nutrients in the forest ecosystems. However, further researches are needed particularly on the effect of species, forest structures, seasons, and climate factors on the plant litter production and decomposition in various types of forest ecosystems.

• Journal of the Korean institute of surface engineering
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• v.46 no.4
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• pp.153-157
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• 2013

The defect like the void or seam is frequently generated in the PCB (Printed Circuit Board) Via-Filling plating inside via hole. The organic additives including the accelerating agent, inhibitor, leveler, and etc. are needed for the copper Via-Filling plating without this defect for the plating bath. However, the decomposition of the organic additive reduces the lifetime of the plating bath during the plating process, or it becomes the factor reducing the reliability of the Via-Filling. In this paper, the interaction of each organic additives and the decomposition of additive were discussed. As to the accelerating agent, the bis (3-sulfopropyl) disulfide (SPS) and leveler the Janus Green B (JGB) and inhibitor used the polyethlylene glycol 8000 (PEG). The research on the interaction of the organic additives and decomposition implemented in the galvanostat method. The additive decomposition time was confirmed in the plating process from 0 Ah/l (AmpereHour/ liter) to 100 Ah/l with the potential change.

• The Journal of Fisheries Business Administration
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• v.45 no.1
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• pp.17-31
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• 2014

This study examines trends in the overall income inequality of fishery household from 2003 to 2012 with the panel data of the Fishery Household Economy Survey. To investigate the potential determinants of income inequality, we decomposes the Gini coefficients into five income sources, fishery income, non-fishery income(non-fishery business income, non-business income), transfer income, irregular income and calculate the impact of each income sources on total income inequality. An evident trend toward increasing inequality of household income was found. Also, we find rising fishery income and non-fishery income play important role in the rapid increase of income inequality. Only transfer income appear to reduce total income inequality.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.4
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• pp.95-101
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• 1990

Orthogonal decomposition technique, not using normal equation, but using observation equation directly, is accepted for adjusting the geodetic network in this paper. The results of study show that the technique is the numerically stable and powerful method in network adjustment by inner constraints or weighted position parameters. Also, it is suitable to middle sized-network and is applicable to Cholesky Factor in the normal equation system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.7
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• pp.1689-1698
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• 1998

In this paper, we present a new method for estimating the parameters of transient-type signal in additive white Gaussian noise. This method makes use of the truncated singular value decomposition of an extended-order auto-correlation-like matrix based on the linear-prediction model. The method is tested on data consisting of two exponentially dampled sinusoidal signals with the same damping factor and different damping factor. Simulation results are illustrated to demonstrate the better performance of the method applied to the auto-correlation-like matrix than that applied to the data matrix.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.34 no.11
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• pp.421-429
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• 1985

With the rapid increase of contingency cases due to complication of power system, the reduction of computation time in contingency analysis has become more significant than ever before. This paper deals with the development of a fast contingency analysis algorithm by using a matrix decomposition method. The proposed matrix decomposition method of contingency analysis yields an accurate solution by using the original triangular factor table. An outstanding feature of this method is of no need of factor table modification for network changes due to contingency outages. The proposed method is also applicable to multiple contingency analysis withremarkable reduction of computation time. The algorithm has been tested for a number of single and multiple contigencies in 17-bus and 50-bus systems. The numerical results show its applicability to practical power systems.