Some properties of cyclic codes†

This paper will investigate the properties of cyclic codes under the transformation,$ It is discovered that for all the non-shortened cyclic codes (binary or (/-nary), if (g(x), (x?1)) =1 then the set of all the codewords is invariant under the transformation f_b. If (g(x), Lx?1)) = (x; ? 1), then the set of all the code words is generated by g(x)/(x ? 1). Next this paper shows a systematic method for the construction of orthogonal cyclic codes in which all the code vectors are orthogonal to each other even to itself     

A novel threshold changeable secret sharing scheme

A(t,n)threshold secret sharing scheme is a fundamental tool in many security applications such as cloud computing and multiparty computing.In conventional threshold secret sharing schemes,like Shamir’s scheme based on a univariate polynomial,additional communication key share scheme is needed for shareholders to protect the secrecy of their shares if secret reconstruction is performed over a network.In the secret reconstruction,the threshold changeable secret sharing(TCSS)allows the threshold to be a dynamic value so that if some shares have been compromised in a given time,it needs more shares to reconstruct the secret.Recently,a new secret sharing scheme based on a bivariate polynomial is proposed in which shares generated initially by a dealer can be used not only to reconstruct the secret but also to protect the secrecy of shares when the secret reconstruction is performed over a network.In this paper,we further extend this scheme to enable it to be a TCSS without any modification.Our proposed TCSS is dealer-free and non-interactive.Shares generated by a dealer in our scheme can serve for three purposes,(a)to reconstruct a secret;(b)to protect the secrecy of shares if secret reconstruction is performed over a network;and(c)to enable the threshold changeable property.     

Application of coding theory to the construction of the Singer difference sets†

In this paper we give a new and simple construction for the cyclic [(q ^m ? 1)/(q ? 1), q ^m?1, q ^m?2(q? 1)]—difference sets (q = p ^γ is a prime power) using the methods of coding theory. The construction is such that, in the case q = 2, the 2-ranks of both the incidence matrix and its complementary matrix are easily determined.     

Effects of Variety, Maturity and Processing on Pear Juice Quality and Protein Stability

?Anjou, Comice, and Bartlett pears were processed into clarified juices from hard green and soft ripened fruits. Processing trials with and without SO₂ were conducted. Effects of variety, maturity and processing on browning, turbidity, proteins, and stability were investigated. Browning increased with heat treatment, and was reduced by processing with SO₂. Total soluble protein content increased with fruit maturity and processing with SO₂. Protein fractions from a clarifying enzyme preparation (mainly arabinase and amylase) with MW in the range of 64,000–92,000 and containing glycoproteins were not removed by fining/clarification. They contributed to protein instability in the clarified pear juices, but could be removed by heat treatment (pasteurization) prior to final filtration and bottling. Our results indicate some enzymes added for clarification during processing may contribute to post-clarification haze and sediment formation.     

水与绿的另类展演舞台——2010台北花博大佳河滨公园设计

2010台北国际花卉博览会是中国台湾第一次举办世界级的博览会;对于这个可促进观光产业发展、岛内花卉与园艺产业成长的机会,应该如何去面对与思考?博览会结束后,除了经济上的效益之外,民众是否藉由这次活动学习到如何爱护我们的环境,与珍惜我们的资源?这些都是在设计过程中不断思索的重点.     

A Diffusion Model with a Concentration-Dependent Diffusion Coefficient for Describing Water Movement in Legumes During Soaking

A mathematical model based on Fick's diffusion equation with a concentration-dependent diffusion coefficient was proposed to describe the absorption of water by legumes. The equation was solved by using a numerical scheme. Parameter study was performed. The model is capable of predicting sigmoidal-shaped water uptake curves common to many legumes. Differences are discussed between the surface resistance boundary condition used in this study and the radiation boundary condition widely used for dehydration calculations. The validity of using the proposed model to described the water uptake of legumes was verified by the good fit between the experimental and theoretical curves.     

EFFECTS OF INTERMOLECULAR INTERACTIONS AND MOLECULAR ORIENTATION ON THE FLUX BEHAVIOR OF XANTHAN GUM SOLUTIONS DURING ULTRAFILTRATION

Conformational changes of xanthan gum as a function of concentration were investigated to elucidate its unusual flux behavior during ultrafiltration (UF). The contribution of hydrogen bonding on structure formation and the molecular orientation of xanthan gum on the flow characteristics were studied rheomechanically and rheo-optically. Known to affect xanthan structure at low concentrations, hydrogen bonding unexpectedly did not show significant influence on xanthan rheological properties up to 2 wt %. The ordered layers formed on the membrane surface proved responsible for the enhanced water removal during UF. This unique behavior could be attributed to the formation of aligned molecular orientation in addition to the viscosity increases during the biphasic region. Significant differences were observed between xanthan fermentation broth and solutions made of commercial xanthan, suggesting the need to control the salt concentration in fermentation broth in order to make UF an effective recovery process for xanthan gum after fermentation.

PRACTICAL APPLICATIONS

The knowledge gained from the present study strengthens fundamental understandings on the conformational changes of xanthan biopolymers during the recovery of xanthan gum from fermentation broth using ultrafiltration (UF). By taking advantage of the aligned molecular orientation, along with controlling the salt concentration in the fermentation broth, UF could be operated at elevated flux to speed up the removal of water from the viscous fermentation broth. The technology should find broad applications in the fermentation industry, especially where viscosity is of concern during the separation and purification of the product.     

决明子蛋白水解产物的抗氧化活性:热和胃肠稳定性,肽鉴定和计算机分析

决明子乃决明(Cassia obtusifolia L.)的干燥成熟种子,被中医界用于治疗各种疾病。本研究探讨决明子水解产物的抗氧化活性和稳定性,并鉴定其中的短肽。决明子蛋白经过碱性蛋白酶水解2～6 h,以超滤膜技术产生3000 u肽组分。UF 2 h(2 h水解产物分离出来的3000 u组分)表现出最强的ABTS·~+清除能力(EC50=229μg/mL)和铁螯合能力(EC50=89μg/mL)。经过热处理和模拟胃肠消化后,UF 2 h的ABTS·~+清除能力都得以保留。UF 2 h仅在模拟胃肠消化胃后保留铁螯合活性。试验通过使用固相萃取,凝胶色谱和高效液相色谱对UF 2 h进行分离纯化。通过质谱分析,鉴定了四个肽:PMPVR(599.29 u),FETLPF(752.34 u),KMRDNL(775.37 u)和LDESKRF(893.50 u)。计算机分析预测,在模拟胃肠消化前,四个肽皆无毒无过敏性。胃肠消化后,四个肽释放的片段仍无毒,仅PMPVR和KMRDNL释放的肽片段无过敏性的。UF 2 h及其活性肽可作为抗氧化剂,用于开发功能性食品和营养保健品。