National Cheng Kung University

About: National Cheng Kung University is a education organization based out in Tainan City, Taiwan. It is known for research contribution in the topics: Population & Thin film. The organization has 49723 authors who have published 69799 publications receiving 1437420 citations. The organization is also known as: NCKU.

Decolorization and biodegradation of reactive dyes and dye wastewater by a developed bacterial consortium

Abstract: A bacterial consortium (consortium GR) consisting of Proteus vulgaris NCIM-2027 and Micrococcus glutamicus NCIM-2168 could rapidly decolorize and degrade commonly-used sulfonated reactive dye Green HE4BD and many other reactive dyes. Consortium GR shows markedly higher decolorization activity than that of the individual strains. The preferable physicochemical parameters were identified to achieve higher dye degradation and decolorization efficiency. The supplementation of cheap co-substrates (e.g., extracts of agricultural wastes) could enhance the decolorization performance of consortium GR. Extent of mineralization was determined with TOC and COD measurements, showing nearly complete mineralization of Green HE4BD by consortium GR (up to 90% TOC and COD reduction) within 24 h. Oxidoreductive enzymes seemed to be involved in fast decolorization/degradation process with the evidence of enzymes induction in the bacterial consortium. Phytotoxicity and microbial toxicity studies confirm that the biodegraded products of Green HE4BD by consortium GR are non-toxic. Consortium GR also shows significant biodegradation and decolorization activities for mixture of reactive dyes as well as the effluent from actual dye manufacturing industry. This confers the possibility of applying consortium GR for the treatment of industrial wastewaters containing dye pollutants.

Enhancing Differential Evolution Utilizing Eigenvector-Based Crossover Operator

Abstract: Differential evolution has been shown to be an effective methodology for solving optimization problems over continuous space. In this paper, we propose an eigenvector-based crossover operator. The proposed operator utilizes eigenvectors of covariance matrix of individual solutions, which makes the crossover rotationally invariant. More specifically, the donor vectors during crossover are modified, by projecting each donor vector onto the eigenvector basis that provides an alternative coordinate system. The proposed operator can be applied to any crossover strategy with minimal changes. The experimental results show that the proposed operator significantly improves DE performance on a set of 54 test functions in CEC 2011, BBOB 2012, and CEC 2013 benchmark sets.

Three-party encrypted key exchange: attacks and a solution

Abstract: Password-based mechanism is the widely used method for authentication since it allows people to choose their own passwords without any assistant device to generate or store. However, people are used to choose easy-to-remember passwords such that guessing attacks could succeed. In 1992, Bellovin and Merritt proposed Encrypted Key Exchange (EKE) protocols for preventing guessing attacks, in which two communication parties A and B securely share a possibly weak password in advance. In large communication environments, it is inconvenient in key management that every two communication parties mutually share a secret. Three-party EKE protocols, in which all parties (clients) share their secrets with a trusted server only, are more suitable for large communication environments. In 1995, Steiner, Tsudik and Waidner proposed a realization of three-party EKE protocol which is later demonstrated that it is vulnerable to undetectable on-line guessing attacks. In this paper, We will show a new off-line guessing attack on Steiner, Tsudik and Waidners' protocol. Besides, we will also propose a new three-party EKE protocol which not only is secure against both the off-line guessing attack and undetectable on-line guessing attacks but also satisfies the security properties of perfect forward secrecy and known-key security.

Audit quality and earnings management for Taiwan IPO firms

Abstract: Purpose – This paper investigates the relationship between audit quality (as measured by auditor size and industry specialization) and earnings management (as measured by unexpected accruals) for Taiwan IPO firms.Design/methodology/approach – First uses unexpected accruals in the modified Jones model to measure earnings management in the IPO process. Then uses auditor type (big five versus non‐big five) and industry specialist to measure audit quality. The hypothesis predicts that Taiwanese firms with higher quality auditors engage less in earnings management in the IPO process. The sample consists of 367 new issues between 1999 and 2002 from the Taiwan Economic Journal database.Findings – It is found that big five auditors are related to less earnings management in the IPO year in Taiwan. This shows that higher quality auditors constrain earnings management for Taiwan IPO firms.Research limitations/implications – The finding shows that high quality auditors constrain earnings management and provide more ...