• The Korean Journal of Food And Nutrition
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• v.33 no.3
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• pp.331-338
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• 2020

The purpose of this study was to examine the effect of noni (Morinda citrifolia) powder on the physicochemical properties and antioxidant activities of ground pork meat. Four samples of ground pork meat were prepared as follow: CON without noni powder, NP0.5 with 0.5% noni powder, NP1.0 with 1.0% noni powder, and NP1.5 with 1.5% noni powder. The moisture content of CON was the highest (p<0.05). The ash, fiber, fat retention, hardness, cohesiveness, gumminess, chewiness, lightness, and yellowness increased with the addition of the noni powder (p<0.05). The protein, fat, water holding capacity, cooking yield, moisture retention, springiness,and redness of the cooked meat were not significantly different among the samples. The pH of CON was the highest among the samples (p<0.05). The TBARS of CON, NP0.5, NP1.0, and NP1.5 were 0.48, 0.41, 0.36 and 0.34 mg/kg, respectively, and the NP1.5 was the lowest (p<0.05). The DPPH radical scavenging activity of CON, NP0.5, NP1.0, and NP1.5 were 10.4%, 20.8%, 34.6% and 45.3%, respectively, and the NP1.5 was the highest (p<0.05). Consequently, these results support the possible use of noni powder for meat product industry, as addition of noni powder enhances the antioxidant activities of ground pork meat.

• Management Science and Financial Engineering
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• v.18 no.2
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• pp.19-22
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• 2012

In the bin-packing problem, we deal with how to pack the items by using a minimum number of bins. In the inverse bin-packing number problem, IBPN for short, we are given a list of items and a fixed number of bins. The objective is to perturb at the minimum cost the item-size vector so that all items can be packed into the prescribed number of bins. We show that IBPN is NP-hard and provide an approximation algorithm. We also consider a variant of IBPN where the prescribed solution value should be returned by a pre-selected specific approximation algorithm.

• Polymer(Korea)
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• v.28 no.6
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• pp.531-537
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• 2004

Various half-ester acrylates were prepared from anhydrides and 2-hydroxyethyl acrylate. Photocurable epoxy modified acrylates were prepared from synthesized half-ester acrylate and neopentylglycol diglycidylether. Physical properties such as hardness, yellowing, tensile strength and elongation were tested and compared as the structure of oligomer in cured-film differs. It was found that viscosity of neopentylglycol diglycidylether-hexahydrophthalic anhydride (NP-HA) was highest. Hardness and tensile strength of photocrosslinked neopentylglycol diglycidylether-hexahydrophthalic anhydride were better than those of other photocrosslinted epoxy acrylates. And 5% weight loss temperature of photocrosslinked neopentylglycol diglycidylether-hexahydrophthalic anhydride was higher than those of other photocrosslinked epoxy acrylates. Value of yellow index of photocrosslinked neopentylglycol diglycidyl ether-succinic anhydride (NP-SA) was lower than the other products.

• Journal of the military operations research society of Korea
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• v.30 no.1
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• pp.30-47
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• 2004

This research considers a Network Diversion Problem (NDP) in the directed graph, which is to identify a minimum cost set of links to cut so that any communication paths from a designated source node to a destination node must include at least one link from a specified set of arcs which is called the diversion arcs. We identify a redundant constraint from an earlier formulation. The problem is known to be NP-hard, however a detailed proof has not been given. We provide the proof of the NP-hardness of this problem. We develop a tabu search algorithm that includes a preprocessing procedure with two steps for removing diversion arcs as well as reducing the problem size. Computational results of the algorithm on instances of general graphs and grid graphs are reported.

• Journal of Korean Institute of Industrial Engineers
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• v.29 no.4
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• pp.253-258
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• 2003

We consider the problem of grouping orders into lots. The problem is modelled by a graph G=(V,E), where each node ${\nu}{\in}V$ denotes order specification and its weight ${\omega}(\nu)$ the orders on hand for the specification. We can construct a lot simply from orders of single specification. For a set of nodes (specifications) ${\theta}{\subseteq}V$, if the distance of any two nodes in $\theta$ is at most d, it is also possible to make a lot using orders on the nodes. The objective is to maximize the number of lots with size exactly $\lambda$. In this paper, we prove that our problem is NP-Complete when $d=2,{\lambda}=3$ and each weight is 0 or 1. Moreover, it is also shown to be NP-Complete when $d=1,{\lambda}=3$ and each weight is 1,2 or 3.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.409-416
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• 2003

We consider the problem of grouping orders into lots. The problem is modelled by a graph G = (V, E). where each node $\nu\;\in\;V$ denotes order specification and its weight $\omega(\nu)$ the orders on hand for the specification. We ran construct a lot simply from orders or single specification For a set of nodes (specifications) $\theta\;\subseteq\;V$, if the distance or any two nodes in $\theta$ is at most d, it is also possible to make a lot using orders on the nodes. The objective is to maximize the number of lots with size exactly $\lambda$. In this paper, we prove that our problem is NP-Complete when d = 2, $\lambda\;=\;3$ and each weight is 0 or 1. Moreover, it is also shown to be NP-Complete when d = 1, $\lambda\;=\;3$ and each weight is 1, 2 or 3

• Korean Management Science Review
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• v.26 no.1
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• pp.65-76
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• 2009

The undirected Steiner tree problem in graphs is known to be NP-hard. The objective of this problem is to find a shortest tree containing a subset of nodes, called terminal nodes. This paper proposes a method based on a two-step procedure to solve this problem efficiently. In the first step. graph reduction rules eliminate useless nodes and edges which do not contribute to make an optimal solution. In the second step, a max-min ant colony optimization combined with Prim's algorithm is developed to solve the reduced problem. The proposed algorithm is tested in the sets of standard test problems. The results show that the algorithm efficiently presents very correct solutions to the benchmark problems.

• Membrane and Water Treatment
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• v.8 no.1
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• pp.1-18
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• 2017

In this study, reuse of biologically treated wastewater of denim washing and dyeing industry has been evaluated by membrane technologies. After that experiments were carried out at laboratory scale in textile dyeing unit by using obtained permeate water samples on 100% cotton based raw fabric belonging to examined industry. During membrane experiments, two different UF (UC100 and UC030) and two different NF (NP010 and NP030) were evaluated under alternative membrane pressures. In permeate water obtained on selected samples, conductivity at the range of $1860-2205{\mu}S/cm$, hardness at the range of 60 to 80 mg/L, total color at the range of 2.4 to 7.6 m-1 and COD at the range of 25-32 mg/L was determined. The following analyzes were performed for the dyed fabrics: perspiration fastness, rub fastness, wash fastness, color fastness to water, color fastness to artificial light, color measurement through the fabric. According to analysis results, selected permeate water have no negative impact on dyeing quality. The study showed that membrane filtration gave good performance for biologically treated textile wastewater, and NF treatment with UF pre-treatment was suitable option for reuse of the effluents.

• Journal of information and communication convergence engineering
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• v.17 no.4
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• pp.246-254
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• 2019

This paper proposes a solution to the problem of finding a subgraph for a given instance of many terminals on a Euclidean plane. The subgraph is a tree, whose nodes represent the chosen terminals from the problem instance, and whose edges are line segments that connect two corresponding terminals. The tree is required to have the maximum number of nodes while the length is limited and is not sufficient to interconnect all the given terminals. The problem is shown to be NP-hard, and therefore a genetic algorithm is designed as an efficient practical approach. The method is suitable to various probable applications in layout optimization in areas such as communication network construction, industrial construction, and a variety of machine and electronics design problems. The proposed heuristic can be used as a general-purpose practical solver to reduce industrial costs by determining feasible interconnections among many types of components over different types of physical planes.

• Journal of the Korean Society for Heat Treatment
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• v.15 no.2
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• pp.57-64
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• 2002

The 22%Cr-5%Ni-3%Mo duplex and 18%Cr-8%Ni austenitic stainless steels have been nitrogen permeated under the $1Kg/cm^2$ nitrogen gas atmosphere at the temperature range of $1050^{\circ}C{\sim}1150^{\circ}C$. The nitrogen-permeated duplex and austenitic stainless steels showed the gradual decrease in hardness with increasing depth below surface. The duplex stainless steel showed nitrogen pearlite at the outmost surface and austenite single phase in the center after nitrogen permeation treatment, while the obvious microstructural change was not observed for the nitrogen-permeated austenitic stainless steel. After solution annealing the nitrogen-permeated stainless steels(NPSA treatment) at $1200^{\circ}C$ for 10 hours, the hardness of the duplex and austenitic stainless steels was constant through the 2 mm thickness of the specimen, and the ${\alpha}+{\gamma}$ phase of duplex stainless steel changed to austenite single phase. Tensile strengths and elongations of the NPSA-treated duplex stainless steel remarkably increased compared to those of solution annealed (SA) duplex stainless steel due to the solution strengthening effect of nitrogen and the phase change from a mixture of ferrite and austenite to austenite single phase, while the NP-treated austenitic stainless steel displayed the lowest value in elongation due to inhomogeneous deformation by the hardness difference between surface and interior.