An e-Learning tool considering similarity measures for manufacturing cell formation

Manufacturing cell formation is the first step in the design of cellular manufacturing system. The primary objective of this step is to cluster machines into machine cells and parts into part families so that the minimum of intercell trips will be achieved. This paper will be focused on the configuration of machine cells considering three types of initial machine-part matrix: binary (zero-one) matrix, production volume matrix, and operation time matrix. The similarity measure uses only information from these types of matrix. A pure combinatorial programming formulation will be developed to maximize the sum of similarity coefficients between machine/part pairs. An e-Learning tool/application to help industrial students and engineers for enhancing their cell formation capability is proposed. This tool is designed to include a novel similarity coefficient-based heuristic algorithm for solving the cell formation problem. To determine the performance of the proposed tool, comparison is made with a well-known tool along a case study.     

The compressibility and compactibility of different types of lactose

Objective: The purpose of this study was to investigate and quantify flow properties, compressibility, and compactibility of various pharmaceutical lactose powders found on the market today (DCL-11, DCL-21, M‐200, Flowlac-100, and Tablettose 70, 80, and 100). Methods: Flow properties were estimated by measuring flow time, angle of repose, and the Hausner ratio. Particle rearrangement was studied using Kawakita's linear model. Compressibility was studied using two ‘out-of-die’ methods: (i) the Heckel model and (ii) a modified Walker model. Compactibility was quantified using two methods: (i) the tensile strength profile (Cp) and (ii) the compactibility factor (Pr). Statistical approach was used to analyze the results. Results: Flow properties of all materials were passable or better, except for M-200, which has very poor flowability. Compressibility results demonstrated that the most compressible lactose is spray-dried grade of lactose (Flowlac-100) and the least compressible is milled lactose (M-200). Compactibility studies showed that β‐lactose (DCL-21) forms tablets with superior tensile strength in comparison with α-lactose. Conclusion: Results of the compressibility study showed that the discriminative power of modified Walker model is greater in comparison with Heckel model. Compactibility methods yield similar and comparable results.     

Extracellular matrix survival signals transduced by focal adhesion kinase suppress p53-mediated apoptosis

In many malignant cells, both the anchorage requirement for survival and the function of the p53 tumor suppressor gene are subverted. These effects are consistent with the hypothesis that survival signals from extracellular matrix (ECM) suppress a p53-regulated cell death pathway. We report that survival signals from fibronectin are transduced by the focal adhesion kinase (FAK). If FAK or the correct ECM is absent, cells enter apoptosis through a p53-dependent pathway activated by protein kinase C lambda/iota and cytosolic phospholipase A2. This pathway is suppressible by dominant-negative p53 and Bcl2 but not CrmA. Upon inactivation of p53, cells survive even if they lack matrix signals or FAK. This is the first report that p53 monitors survival signals from ECM/FAK in anchorage- dependent cells.     

Implicit Meshes for Effective Silhouette Handling

Using silhouettes in uncontrolled environments typically requires handling occlusions as well as changing or cluttered backgrounds, which limits the applicability of most silhouette based methods. For the purpose of 3-D shape modeling, we show that representing generic 3-D surfaces as implicit surfaces lets us effectively address these issues. This desirable behavior is completely independent from the way the surface deformations are parame-trized. To show this, we demonstrate our technique in three very different cases: Modeling the deformations of a piece of paper represented by an ordinary triangulated mesh; reconstruction and tracking a person’s shoulders whose deformations are expressed in terms of Dirichlet Free Form Deformations; reconstructing the shape of a human face parametrized in terms of a Principal Component Analysis model. Electronic supplementary material Electronic supplementary material is available for this article at and accessible for authorised users. This work was supported in part by the Swiss National Science Foundation     

Structural Feature and Electrochemical Performance of h-LiMnBO3 and Its Carbon Coated Material Prepared by Microwave Synthesis

采用微波合成法制备了LiMnBO3及其碳包覆材料LiMnBO3/C。考察了烧结温度和配料比对LiMnBO3结构的影响。利用XRD、SEM、HR-TEM对材料的结构和形貌进行了表征。通过恒电流充/放电性能及交流阻抗测试研究了材料的电化学性能。结果表明,实验所得LiMnBO3具有六方晶体结构(即制得h-LiMnBO3)。750℃烧结温度下,反应25 min,且nLi:nB:nMn=1:1:1时,材料结晶较为完善、晶粒细小、形貌规整。碳包覆后材料充/放电性能及电导率均有提高。LiMnBO3/C的初次放电比容量达到50.3 mAh/g。     

Melt granulation in fluidized bed: a comparative study of spray-on versus in situ procedure

Objective: The aim of this study was to investigate the influence of process parameters, binder content and binder addition method on characteristics of the granules obtained by melt granulation (MG) in fluidized bed.

Methods: Spray-on experiments were performed according to 2³ full factorial design. The effect of binder content, molten binder feed rate, and spray air pressure on granule size and size distribution, granule shape, ?owability and drug release rate was investigated. In the in situ experiments, the influence of binder particle size and binder content was evaluated. Solid-state characterization was performed by means of differential scanning calorimetry, X-ray powder diffraction and Fourier transform infrared spectroscopy.

Results: Size of the granules obtained by spray-on procedure was significantly influenced by binder content and spray air pressure, while the width of particle size distribution was mainly affected by binder feed rate. Spray air pressure showed the most significant influence on granule shape. It was shown that smooth and spherical particles with good flow properties may be obtained by both procedures, spray-on and in situ MG. The results obtained indicated the influence of agglomeration mechanism on granule sphericity, with higher degree of granule sphericity observed when immersion and layering was the dominant mechanism. Paracetamol release from granulates was very rapid, but after compression of the granules into tablets, drug release was considerably slower. Solid-state analysis confirmed that the physical form of the granulate components remained unaffected after the MG process.

Conclusion: The results presented indicate that MG in fluidized bed could be a good alternative to conventional granulation techniques.     

Cryptanalysis of the Tillich�CZ��mor Hash Function

At CRYPTO ’94, Tillich and Zémor proposed a family of hash functions, based on computing a suitable matrix product in groups of the form SL₂(\mathbbF_2ⁿ)SL_{2}(\mathbb{F}_{2^{n}}). We show how to construct collisions between palindromic bit strings of length 2n+2 for Tillich and Zémor’s construction. The approach also yields collisions for related proposals by Petit et al. from ICECS ’08 and CT-RSA ’09.     

Herpes simplex and lymphocytic choriomeningitis viruses in infections of the central nervous system--clinical and cerebrospinal fluid characteristics

INTRODUCTION: A great number of various viruses are stated as the cause of acute infections and damages of the central nervous system. In most cases these are minor damages which exhibit as meningeal syndrome and a specific finding in the cerebrospinal fluid. According to the dominant location, central nervous system infections can take a form of meningitis, encephalitis or myelitis. Since the inflammatory process of the meninges can not be separated from the inflammatory process of the brain, we usually speak of meningoencephalitis. The etiological diagnosis of meningitis and encephalitis is established by isolating the virus from the cerebrospinal fluid and by finding the presence of the specific antibodies in the blood and in the cerebrospinal fluid. The most common causes of the viral meningitis are Enteroviruses, the Mumps virus, Arthropode borne viruses, the Herpes viruses, Adeno viruses and the Lymphocytic choriomeningitis virus. The aim of our study was to establish the correlation between the clinical features and immunological and cerebrospinal fluid changes and the degree of the damage to the blood-brain barrier during the infections of the central nervous system, caused by the Herpes Simplex virus and the Lymphocytic choriomeningitis virus. MATERIAL AND METHODS: From a group of 103 patients, who had been treated for viral meningitis and meningoencephalitis, a group of 27 patients with established specific viral etiology--Herpes Simplex virus and Lymphocytic choriomeningitis virus, had been taken into the account. Herpes Simplex infection had been proven by the complement binding reaction and the neutralisation test of the even samples of serum. The diagnosis of Lymphocytic choriomeningitis was confirmed by the immunofluorescence test of the pharynx swabs and cerebrospinal fluid. The clinical features, such as body temperature, encephalitic signs, and electroencephalographic findings had been followed and compared. RESULTS: Herpes Simplex infection had been found in 20 patients, Lymphocytic choriomeningitis had been proven in 7 patients. All the patients had increased body temperature. Only four of the patients exhibited encephalitic signs, all infected by the Herpes Simplex virus. Patients from the Herpes Simplex group showed various degrees of consciousness disturbances, ranging from somnolence to coma, while the Lymphocytic choriomeningitis patients exhibited none. Higher pleocytosis and protein level had been found in the Lymphocytic choriomeningitis group. DISCUSSION: Viral diseases of the central nervous system are the result of the direct damage of the brain and meninges by the virus and immunological processes. Herpes Simplex meningitis usually has a good prognosis. Lymphocytic choriomeningitis has longer course of the disease and exhibits more severe clinical features. CONCLUSION: In cases of the central nervous system infections, caused by Herpes Simplex virus or Lymphocytic choriomeningitis virus, the correlation between the severeness of clinical features and the degree of damage of the blood-brain barrier, the level of pleocytosis and the increase of the cerebrospinal fluid proteins had been established.