• 산업경영시스템학회지
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• 제33권4호
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• pp.1-9
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• 2010

In this paper, we consider a two-machine re-entrant permutation flowshop scheduling problem with the objective of minimizing total flowtime, and suggest branch and bound algorithms for the scheduling problem. In this scheduling problem, each job must be processed twice on each machine, that is, each job should be processed on the two machines in the order of machine 1, machine 2 and then machine 1 and machine 2. In this research, based on the results of existing researches for re-entrant permutation flowshop scheduling problems, various dominance properties, lower bound and heuristic algorithm are suggested for the problem, and those are used to develop branch and bound algorithms. In the computational experiments for evaluation of the performance of the algorithms, the suggested branch and bound algorithms are tested on randomly generated test problems and results are reported.

• Membrane and Water Treatment
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• 제8권4호
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• pp.337-353
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• 2017

Membrane fouling at different solids retention times (SRT) (7, 12 and 20 days) was studied under well-controlled conditions in a laboratory-scale aerobic submerged membrane bioreactor under constant biomass concentration using a synthetic high strength wastewater. An increase in SRT was found to improve membrane performance and this correlated to changes in the total production of bound extracellular polymeric substances (EPS), and the composition and properties of bound EPS using X-ray photoelectron spectroscopy (XPS) and Fourier transform-infrared spectroscopy (FTIR) and floc sizes. A larger amount of total bound EPS was found at the lowest SRT (7 days) tested but the ratio of proteins (PN) to carbohydrates (CH) in bound EPS increased with an increase in SRT. Similarly, the quantity of soluble microbial products (SMP) decreased with an increase in SRT and the SMP PN/CH ratio increased with an increase in SRT. SMP concentrations positively correlated to the percentage of membrane pore blocking resistance. The quantity of total bound EPS and total SMP positively corresponded to the membrane fouling rate, while the PN/CH ratio in the bound EPS and SMP negatively correlated to the membrane fouling rate. The results show that both the quantity and composition of bound EPS and SMP and floc sizes are important in controlling membrane fouling.

• 충청수학회지
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• 제21권2호
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• pp.223-230
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• 2008

In this paper, we present an upper bound of the reciprocal sums of generalized subset-sum-distinct sequences with respect to the first terms of the sequences. And we show the suggested upper bound is best possible. This is a kind of generalization of [1] which contains similar result for classical subset-sum-distinct sequences.

• 소성∙가공
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• 제6권3호
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• pp.233-238
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• 1997

The estimation of the forming force required for metal forming process is unavoidable for selecting suitable machine and dimensioning die and punch parts. For this purpose the upper-bound method turns out to be very practical in simple two-dimensional cases under well-known boundary conditions. However, the application of this method for complicated two-or three-dimentional cases is very limited or practically impossible. The modified application of FEM in a manner of applying the upper bound method(the so-called Upper-bound Finite Element Simulation Method) fortunately provides the posibility of getting important information about the forming process in a simple and quick way before realizing the process on the machine. It is expected to function successfully even in three-dimentional cases. The application procedure has been explained for two-dimensional cases and its usefulness shown.

• Journal of Communications and Networks
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• 제10권1호
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• pp.5-9
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• 2008

Researchers have investigated many upper bound techniques applicable to error probabilities on the maximum likelihood (ML) decoding performance of turbo-like codes and low density parity check (LDPC) codes in recent years for a long codeword block size. This is because it is trivial for a short codeword block size. Previous research efforts, such as the simple bound technique [20] recently proposed, developed upper bounds for LDPC codes and turbo-like codes using ensemble codes or the uniformly interleaved assumption. This assumption bounds the performance averaged over all ensemble codes or all interleavers. Another previous research effort [21] obtained the upper bound of turbo-like code with a particular interleaver using a truncated union bound which requires information of the minimum Hamming distance and the number of codewords with the minimum Hamming distance. However, it gives the reliable bound only in the region of the error floor where the minimum Hamming distance is dominant, i.e., in the region of high signal-to-noise ratios. Therefore, currently an upper bound on ML decoding performance for turbo-like code with a particular interleaver and LDPC code with a particular parity check matrix cannot be calculated because of heavy complexity so that only average bounds for ensemble codes can be obtained using a uniform interleaver assumption. In this paper, we propose a new bound technique on ML decoding performance for turbo-like code with a particular interleaver and LDPC code with a particular parity check matrix using ML estimated weight distributions and we also show that the practical iterative decoding performance is approximately suboptimal in ML sense because the simulation performance of iterative decoding is worse than the proposed upper bound and no wonder, even worse than ML decoding performance. In order to show this point, we compare the simulation results with the proposed upper bound and previous bounds. The proposed bound technique is based on the simple bound with an approximate weight distribution including several exact smallest distance terms, not with the ensemble distribution or the uniform interleaver assumption. This technique also shows a tighter upper bound than any other previous bound techniques for turbo-like code with a particular interleaver and LDPC code with a particular parity check matrix.

• 산업경영시스템학회지
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• 제19권39호
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• pp.9-18
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• 1996

Many algorithms have been developed for optimizing the asymmectric traveling salesman problem known as a representative NP-Complete problem. The most efficient ones of them are branch and bound algorithms based on the subtour elimination approach. To increase efficiency of the branch and bound algorithm. number of decision nodes should be decreased. For this the minimum bound that is more close at the optimal solution should be found or an effective bounding strategy should be used. If the optimal solution has been known, we may apply it usefully to branching. Because a good feasible solution should be found as soon as possible and have similar features of the optimal solution. By the way, the upper bound solution in branch and bound algorithm is most close at the optimal solution. Therefore, the upper bound solution can be used instead of the optimal solution and information of which can be applied to new branching criteria. As mentioned above, this paper will propose an effective branching rule using the information of the upper bound solution in the branch and bound algorithm. And superiority of the new branching rule will be shown by comparing with Bellmore-Malone's one and carpaneto-Toth's one that were already proposed.

• Geomechanics and Engineering
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• 제11권4호
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• pp.587-605
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• 2016

This study aimed to develop upper and lower bounds to predict the tunnel support pressure under the pile tip during the circular tunnel excavation. Most previous studies on the upper and lower bound methods were carried out for the single ground structures, e.g., retaining wall, foundation, ground anchor and tunnel, in the homogeneous ground conditions, since the pile-soil-tunnel interaction problem is very complicated and sophisticated to solve using those bound methods. Therefore, in the lower bound approach two appropriate stress fields were proposed for single pile and tunnel respectively, and then they were superimposed. In addition, based on the superimposition several failure mechanisms were proposed for the upper bound solution. Finally, these upper bound mechanisms were examined by shear strain data from the laboratory model test and numerical analysis using finite element method.

• 산업경영시스템학회지
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• 제24권62호
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• pp.21-32
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• 2001

The two-dimensional guillotine cutting problem is to maximize sum of piece profits that cut from one stock rectangle and widely applied in the industry. The branch-and-bound method for this problem uses complementarily several upper bounds(the Gilmore and Gomoryp[8]'s two-dimensional knapsack function and the Hifi and Zissimopoulos[10]'s method using one-dimensional knapsack problem, etc) to reduce the number of searched nodes. These upper bounds has a shortcoming that does not consider the bound and layout of pieces simultaneously. In this paper, we propose an efficient upper bound which can complement the shortcoming of existing upper bounds. The proposed upper bound needs less memory spaces and computing time. Computational results show that the proposed upper bound significantly contribute to reduce the computational amount of time and number of searched nodes in tree.

• Preventive Nutrition and Food Science
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• 제15권1호
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• pp.36-43
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• 2010

The purpose of this study was to investigate the phenolic acid, proanthocyanidin (PAs), and flavonol glycoside contents, as well as the antioxidant activities of pine needle extracts from six species of young pine trees. The extracts were prepared from Section Pinus (Diploxylon): P. densiflora, P. sylvestris, P. pinaster and P. pinea, and Section Strobus (Haploxylon): P. koraiensis and P. strobus. Phenolics were extracted from pine needles with 80% acetone to obtain the soluble free fraction, and insoluble residues were digested with 4 M NaOH to obtain bound ethyl acetate and bound water fractions. Phenolics were analyzed by HPLC, and the hydrophilic antioxidant activity was measured using oxygen radical absorbance capacity (ORAC). Total phenolic and flavonoid contents of the soluble free fraction were higher than those of the bound ethyl acetate and bound water fractions. The main phenolics were monomers and polymers of PAs in the soluble free fraction, and phenolic acids and flavonol glycosides in bound ethyl acetate fraction. Flavonol glycosides found in different species of pine needles were qualitatively similar within fractions, but composition varied among Pinus sections. High levels of kaempferol arabinoside and an unknown compound were present in all Strobus species. The soluble free fraction had the highest antioxidant activity, followed by bound ethyl acetate and bound water fractions.

• 약학회지
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• 제44권4호
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• pp.347-353
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• 2000

To examine influence of artificial digestive juice on the antitumor activity of Ganoderma lucidum-A(GL-A), protein-bound polysaccharide from Ganoderma lucidum, we compared the digested protein-bound polysaccharide with undigested one both on immunopotentiating activity and influence of digestive juices. Protein-bound polysaccharide GL-B was obtained by digesting the antitumor component GL-A with artificial digestive Juices in vitro. When GL-A was administered orally to sarcoma 180 tumor-bearing ICR mice, the life prolonging effect was exhibited in a dose dependent manner Not only GL-A but GL-B increased the production of colony forming unit (CFU) to 10- and 8-fold of that of the control, respectively. Both of the protein-bound polysaccharides also showed the secretion of nitric oxide in RAW 264.7 cell lines to 3.5-and 3.7-fold of that of the control, respectively: GL-A activated components of the alternative complement pathway, whereas GL-B did not. In humoral immunity GL-A increased the activity of alkaline phosphatase in differentiated B cells to 3 times and GL-B to 4 times of that of the control. These results showed that the artificial digestive juices had no influence on the antitumor activity of the protein-bound polysaccharide from Ganoderma lucidum and that its immunomodulating activity retained after treatment with artificial digestive juice. And this provides a basis of the protein-bound polysaccharide of Ganoderma lucidum as an peroral anticancer drug.