A New Secure Authenticated Group Key Transfer Protocol

Group key transfer protocols depend on a mutually trusted key generation center (KGC) to generate group keys and transport group keys to all group members secretly. Generally, KGC encrypts group keys under another secret key shared with each user during registration. In this paper, we propose a novel secure authenticated group key transfer protocol using a linear secret sharing scheme (LSSS) and ElGamal cryptosystem, where KGC broadcasts group key information to all group members. The confidentiality of this transformation is guaranteed by this LSSS and ElGamal cryptosystem. We also provide authentication for transporting this group key. Goals and security threats of our protocol are analyzed in detail.     

Optimal preventive maintenance policies in a serial production system

There have been many publications dealing with preventive maintenance policies for stochastically deteriorating systems. However, most of them study systems having one device subject to failure. Much of the limited research dealing with multi-device production systems has been conducted through simulation experiments. In this paper, the preventive maintenance problem for serial production systems is formulated as a mathematical model. This formulation permits management to analyse the impact of a preventive maintenance policy on a serial production system without resorting to simulation. Numerical examples are used to provide managerial implications for maintaining a serial production system. The results show that the operating characteristics of the stations are interrelated; therefore, it is important to examine the joint effects of a maintenance policy on the various stations of the production system simultaneously rather than study each station separately.     

MONITORING THE DAMPING CHARACTERISTICS OF LIQUID FOODS IN CYLINDRICAL CONTAINERS

The oscillatory damping characteristics of model food solutions and gels in cans were studied in an apparatus designed for nondestructive testing. Oscillations, resulting from a small angular displacement, were monitored by an accelerometer and recorded by a fast recorder. An empirical damping coefficient, derived from an exponential decay constant was found to be sufficiently sensitive to monitor the apparent viscosity of liquid contents. In the case of gelation, the magnitude of the damping coefficient considerably increased when a very soft gel was formed. When the gel gained rigidity, however, there was a dramatic drop in the coefficient value to levels well below those of the nongelled contents. At this stage, however, there was also an appreciable drop in the system's natural frequency which could easily be recorded. This provided a complementary criterion that enabled unambiguous distinction between “viscous” and gelled contents.     

Viscoelastic Behavior of Whey Protein Isolates at the Sol-Gel Transition Point

The flow behavior of whey protein isolates (WPI) was studied in systems processed under different conditions. Experiments were undertaken to study effects of heating conditions (temperature/time), pH, solid content, calcium chloride, and guanidinium hydrochloride addition on the gelation of whey protein isolate solutions. The rheological data demonstrated a power-law frequency dependence of the viscoelastic functions G″ (ω) and G″ (ω) and a frequency-independent tan δ determined from a multi-frequency scan of tan δ vs gelling time at the gel point. The power-law exponents (n) obtained from these dynamic measurements for determining the sol-gel transition point were between 0.62 and 0.69. Those values suggest a percolation mechanism for the gelation process.     

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。     

New approach to time-domain analysis for stability robustness of dynamic systems

This paper presents a new approach to the analysis of the stability robustness of dynamic systems in state-space models. By continuously perturbing the state matrix, instead of solving the Lyapunov equation, an elegant stability robustness fundamental is derived. Subsequently, the allowable norm bound of the error matrix can be obtained under weakly structured perturbations, and the magnitude bound on individual elements of the error matrix can be obtained under highly structured perturbations. The merits of the theorems and corollary developed are demonstrated by two examples where the results achieved are much better than those already published in the literature. The concept that the perturbed state matrix would depend on the operating frequencies is also introduced.     

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     

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.