Decision Supporting Methodology and System Based on Theory of Constraints for Making an Optimal Product Portfolio Strategy in Shipbuilding Industry

Shipbuilding is a typical ‘build to order’ industry. It has a business model that generates revenues from building various ships and offshore products in accordance with owner’s requirements at each production stage. Under uncertainty in shipping market, it is very essential for the shipbuilder to prepare the fast and competitive decision for product portfolio strategy in order to maximize contribution margin by exploiting production facilities and constraints. TOC(theory of constrains) proposed by Dr. goldratt in 1979 has been evolved into a management philosophy with practices and principles spanning a multitude of operations management sub-disciplines.[1] In this study, we introduce the unique decision supporting methodology for the optimal product portfolio sets based on TOC. This methodology is established by adopting the concept of Drum Buffer Rope (DBR)[2] in constraints planning and Throughput Account (TA)[3][4][5] in management accounting of TOC. In addition, Decision Supporting System (DSS)[6] is implemented by applying this methodology. This DSS system provides a throughput estimator with reflecting the cost structure of shipbuilding industry and a resource simulator built on heuristic algorithms to operate major constraint-resources in shipyard such as dock, quay and pre-erection area etc. Several examples are presented to show that the proposed methodology and system can effectively support the strategic decision-making process of a global shipbuilding company

One-dimensional broadband phononic crystal filter with unit cells made of two non-uniform impedance-mirrored elements

A one-dimensional finite-sized phononic crystal(PC) made of a specially-configured unit cell is proposed to realize broad bandpass, high-performance filtering. The unit cell is specially-configured with two elements having mirrored impedance distributions of each other. One element has a non-uniform impedance distribution that is so engineered as to maximize wave transmission in the pass band and to minimize transmission in the adjacent stop band while the other, exactly the mirrored distribution. The mirroring approach naturally yields the overall impedance contrast within the resulting unit cell, necessary to form stop bands in a PC of the unit cells. More importantly, the good transmission performance of the orginally-engineered element can be preserved by the approach because no additional impedance mismatch is introduced along the interface of the two impedance-mirrored elements. Extraordinary performance of the PC filter made of the proposed unit cell, such as high transmission, large bandwidth and sharp roll-off, is demonstrated by using one-dimensional longitudinal elastic wave problems. Copyright 2013 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License. [http://dx.doi.org/10.1063/1.4790638ope

Poly(L-histidine)-tagged 5-aminolevulinic acid prodrugs: new photosensitizing precursors of protoporphyrin IX for photodynamic colon cancer therapy

Renjith P Johnson,1* Chung-Wook Chung,2* Young-Il Jeong,2 Dae Hwan Kang,2 Hongsuk Suh,3 Il Kim,11WCU Centre for Synthetic Polymer Bioconjugate Hybrid Materials, Department of Polymer Science and Engineering, Pusan National University, Pusan, 2National Research and Development Center for Hepatobiliary Cancer, Pusan National University, Yangsan Hospital, Yangsan, Gyeongnam, 3Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Pusan, Korea*These authors contributed equally to this workBackground: 5-Aminolevulinic acid (ALA) and its derivatives have been widely used in photodynamic therapy. The main drawback associated with ALA-based photodynamic therapy (ALA-PDT) and ALA fluorescence diagnosis results from the hydrophilic nature of ALA and lack of selectivity for tumor versus nontumor cells. The application of certain triggers, such as pH, into conventional sensitizers for controllable 1O2 release is a promising strategy for tumor-targeted treatment.Methods: A series of pH-sensitive ALA-poly(L-histidine) [p(L-His)n] prodrugs were synthesized via ring opening polymerization of 1-benzyl-N-carboxy-L-histidine anhydride initiated by the amine hydrochloride group of ALA itself. As an alternative to ALA for PDT, the synthesized prodrugs were used to treat a cultured human colon cancer HCT116 cell line under different pH conditions. The effect of ALA-p(L-His)n derivatives was evaluated by monitoring the fluorescence intensity of protoporphyrin IX, and measuring the cell survival rate after suitable light irradiation.Results: The cytotoxicity and dark toxicity of ALA and synthesized ALA-p(L-His) derivatives in HEK293T and HCT116 cells in the absence of light at pH 7.4 and 6.8 shows that the cell viability was relatively higher than 100%. ALA-p(L-His)n showed high phototoxicity and selectivity in different pH conditions compared with ALA alone. Because the length of the histidine chain increases in the ALA-p(L-His)n prodrugs, the PDT effect was found to be more powerful. In particular, high phototoxicity was observed when the cells were treated with ALA-p(L-His)15, compared with treatment using ALA alone.Conclusion: The newly synthesized ALA-p(L-His)n derivatives are an effective alternative to ALA for enhancing protoporphyrin IX production and the selectivity of the phototoxic effect in tumor cells.Keywords: 5-aminolevulinic acid, photodynamic therapy, poly(L-histidine), bioconjugate, cancer cell

A Synergistic Anti-Diabetic Effect by Ginsenosides Rb1 and Rg3 through Adipogenic and Insulin Signaling Pathways in 3T3-L1 Cells

Although ginsenosides Rb1 and Rg3 have been identified as the significant ginsenosides found in red ginseng that confer anti-diabetic actions, it is unclear whether insulin-sensitizing effects are mediated by the individual compounds or by their combination. To determine the effect of ginsenosides Rb1 and Rg3 on adipocyte differentiation, 3T3-L1 preadipocytes were induced to differentiate the standard hormonal inducers in the absence or presence of ginsenosides Rb1 or Rg3. Additionally, we determined the effects of Rb1, Rg3, or their combination on the expression of genes related to adipocyte differentiation, adipogenic transcription factors, and the insulin signaling pathway in 3T3-L1 cells using semi-quantitative RT-PCR. Rb1 significantly increased the expression of CEBP alpha, PPAR gamma, and aP2 mRNAs. However, Rg3 exerted its maximal stimulatory effect on these genes at 1 mu M concentration, while a high concentration (50 mu M) showed inhibitory effects. Similarly, treatment with Rb1 and Rg3 (1 mu M) increased the expression of IRS-1, Akt, PI3K, GLUT4, and adiponectin. Importantly, co-treatment of Rb1 and Rg3 (9:1) induced the maximal expression levels of these mRNAs. Our data indicate that the anti-diabetic activity of red ginseng is, in part, mediated by synergistic actions of Rb1 and Rg3, further supporting the significance of minor Rg3

Quality characteristics of rice inoculated with Inonotus obliquus mycelia and incubated under different cultivating conditions

This study was performed to investigate the quality characteristics of Inonotus obliquus mycelia rice incubated with I. obliquus (KCTC 256152). Different volumes of mycelial culture of I. obliquus were used for production of I. obliquus mycelia rice. Twenty percent of the mycelial culture was added to rice and designated as IOR-20, 30% as IOR-30 and 40% as IOR-40. Using the I. obliquus mycelia rice, the contents of β-1,3-glucan, betulin, total polyphenol and 1,1-diphenyl-2-picrylhydrazol (DPPH) radical scavenging activity, Hunter`s color values, free amino acid content, and mineral content were investigated. The β-1,3-glucan content in I. obliquus mycelia rice were in the order of IOR-30(729.7 μg/g) > IOR-20(716.0 μg/g) > IOR-40(690.5 μg/g) and those of betulin content were OR-30(1273.7 μg/g) > IOR-40 (1247.81 μg/g) > IOR-20 (1209.82 μg/g). The highest content of total polyphenols (353.6 μg/g) and activity of DPPH radical scavenging were observed in the IOR-30. The higher contents for β-1,3-glucan, betulin, polyphenol, and DPPH radical scavenging were found in 30% mycelial culture treatment, showing the best condition for the production of I. obliquus mycelia. Aspartic acid (10.28 to 29.44 μg/100 g), threonine (5.43 to 11.00 μg/100 g), serine (8.84 to 14.53 μg/100 g), glutamic acid (31.01 to 53.61 μg/100 g), glycine (4.77 to 10.26 μg/100 g), valine (2.93 to 6.57 μg/100 g), and lysine (5.20 to 14.41 μg/100 g) contents were determined in the I. obliquus mycelia rice and the order was as follows; IOR-20>IOR-30>IOR-40. The IOR-30 sample exhibited the highest levels of K(899.1±8.1 mg/kg), Mg(427.3±9.3 mg/kg), Ca(480.2±6.9 mg/kg), Na(296.1±9.2 mg/kg).Keywords: Rice, Inonotus obliquus (KCTC 256152), β-1,3-glucan, betulin, quality characteristicsAfrican Journal of Biotechnology Vol. 12(33), pp. 5131-513

Electroactive Artificial Muscles Based on Functionally Antagonistic Core–Shell Polymer Electrolyte Derived from PS-b-PSS Block Copolymer

Electroactive ionic soft actuators, a type of artificial muscles containing a polymer electrolyte membrane sandwiched between two electrodes, have been intensively investigated owing to their potential applications to bioinspired soft robotics, wearable electronics, and active biomedical devices. However, the design and synthesis of an efficient polymer electrolyte suitable for ion migration have been major challenges in developing high-performance ionic soft actuators. Herein, a highly bendable ionic soft actuator based on an unprecedented block copolymer is reported, i.e., polystyrene-b-poly(1-ethyl-3-methylimidazolium-4-styrenesulfonate) (PS-b-PSS-EMIm), with a functionally antagonistic core–shell architecture that is specifically designed as an ionic exchangeable polymer electrolyte. The corresponding actuator shows exceptionally good actuation performance, with a high displacement of 8.22 mm at an ultralow voltage of 0.5 V, a fast rise time of 5 s, and excellent durability over 14 000 cycles. It is envisaged that the development of this high-performance ionic soft actuator could contribute to the progress toward the realization of the aforementioned applications. Furthermore, the procedure described herein can also be applied for developing novel polymer electrolytes related to solid-state lithium batteries and fuel cells