Using box indices in supporting comparison in multiobjective optimization

Because of the conflicting nature of criteria or objectives, solving a multiobjective optimization problem typically requires interaction with a decision maker who can specify preference information related to the objectives in the problem in question. Due to the difficulties of dealing with multiple objectives, the way information is presented plays a very important role. Questions posed to the decision maker must be simple enough and information shown must be easy to understand. For this purpose, visualization and graphical representations can be useful and constitute one of the main tools used in the literature. In this paper, we propose to use box indices to represent information related to different solution alternatives of multiobjective optimization problems involving at least three objectives. Box indices are an intelligible and easy to handle way to represent data. They are based on evaluating the solutions in a natural and rough enough scale in order to let the decision maker easily recognize the main characteristics of a solution at a glance and to facilitate comparison of two or more solutions in an easily understandable way.     

LARGE DIFFERENCES BETWEEN CONSECUTIVE PRIMES

We use a sieve method together with mean and large value resultsfor Dirichlet polynomials to prove that where p_n is the nth prime number.     

Chemical profiles of birch and alder bark by ambient mass spectrometry

Desorption atmospheric pressure photoionization (DAPPI) is an ambient mass spectrometry (MS) technique that allows the analysis of both polar and nonpolar compounds directly from the surfaces of various sample types. Here, DAPPI was used to study the chemical profiles in different parts of birch and alder tree barks. Four distinct fractions of Betula pendula (silver birch) bark were collected from three different developmental stages of the stem, after which the chemical profiles of the different tissue types were measured. Of special interest were triterpenoids, a class of important defensive substances, which are found in the bark of the silver birch. Additionally, the chemical profiles of lenticels and the surrounding surfaces in the phellem of B. pendula (silver birch), Alnus glutinosa (black alder), and Alnus incana (gray alder) were screened with DAPPI. Another ambient MS technique, laser ablation atmospheric pressure photoionization (LAAPPI), was further used for the mass spectrometry imaging of lenticels on the B. pendula phellem. All the studied birch bark fractions showed individual chemical profiles in DAPPI. The mass spectra from the young apical stem and the transition zone resembled each other more than the mature stem. Instead, the phellem was found to contain a high amount of triterpenoids in all the developmental stages of the stem. The most intense peaks in the DAPPI mass spectra of the birch bark fractions were those of betulin and lupeol. Betulinic and betulonic acid peaks were intense as well, and these compounds were detected especially in the lenticels of the tree samples.

Graphical abstract

     

Improving the computational efficiency in a global formulation (GLIDE) for interactive multiobjective optimization

In this paper, we present a new general formulation for multiobjective optimization that can accommodate several interactive methods of different types (regarding various types of preference information required from the decision maker). This formulation provides a comfortable implementation framework for a general interactive system and allows the decision maker to conveniently apply several interactive methods in one solution process. In other words, the decision maker can at each iteration of the solution process choose how to give preference information to direct the interactive solution process, and the formulation enables changing the type of preferences, that is, the method used, whenever desired. The first general formulation, GLIDE, included eight interactive methods utilizing four types of preferences. Here we present an improved version where we pay special attention to the computational efficiency (especially significant for large and complex problems), by eliminating some constraints and parameters of the original formulation. To be more specific, we propose two new formulations, depending on whether the multiobjective optimization problem to be considered is differentiable or not. Some computational tests are reported showing improvements in all cases. The generality of the new improved formulations is supported by the fact that they can accommodate six interactive methods more, that is, a total of fourteen interactive methods, just by adjusting parameter values.     

Hydrolytic reactions of cyclic bis(3′‐5′)diadenylic acid (c‐di‐AMP)

Hydrolytic reactions of cyclic bis(3′‐5′)diadenylic acid (c‐di‐AMP) have been followed by Reversed phase high performance liquid chromatography (RP‐HPLC) over a wide pH range at 90 °C. Under neutral and basic conditions (pH ≥ 7), disappearance of the starting material (first‐order in [OH^?]) was accompanied by formation of a mixture of adenosine 2′‐monophosphate and 3′‐monophosphate (2′‐AMP and 3′‐AMP). Under very acidic conditions (from H₀ = ?0.7 to 0.2), c‐di‐AMP undergoes two parallel reactions (first‐order in [H⁺]): the starting material is cleaved to 2′‐AMP and 3′‐AMP and depurinated to adenine (i.e., cleavage of the N‐glycosidic bond), the former reaction being slightly faster than the latter one. At pH 1–3, isomerization to cyclic bis(2′‐5′)diadenylic acid competes with the depurination. Copyright © 2012 John Wiley & Sons, Ltd.     

Conformational polymorphism and amphiphilic properties of resorcinarene octapodands

o-Nitroaniline functionalized resorcinarene octapodands 1-5 with pendant methyl, ethyl, pentyl, nonyl or 1-decenyl groups, respectively, were synthesized and their structural properties investigated using X-ray crystallography and NMR spectroscopy. The upper rim of each podand is identical containing flexible side arms, in which rotation around the -OCH(2)CH(2)N- linkers create excellent possibilities for polymorphism. Two conformational polymorphs of acetone solvate of 2 were identified containing different side arm orientation and crystal packing. Compound 1 crystallized from acetone and nitromethane yielding two pseudopolymorphs with different packing motifs. The longer alkyl chains of 3-5 lead to differences in solubility and induce amphiphilic properties, which were studied at the air-water interface using the Langmuir-film technique. Crystals of amphiphilic compound 5, which has hydrophobic alkyl tails at the lower rim and hydrophilic nitroaniline groups at the upper rim, showed an interesting packing motif with alternating aromatic and aliphatic layers. Versatile structures of the octapodands in solid state and in solution serve as an example of how conformational flexibility can be utilized in crystal engineering and creating self-assembling monolayer structures.     

Zero-correlation linear cryptanalysis of reduced-round LBlock

Zero-correlation linear attack is a new method developed by Bogdanov et al. (ASIACRYPT 2012. LNCS, Springer, Berlin, 2012) for the cryptanalysis of block ciphers. In this paper we adapt the matrix method to find zero-correlation linear approximations. Then we present several zero-correlation linear approximations for 14 rounds of LBlock and describe a cryptanalysis for a reduced 22-round version of LBlock. After biclique attacks on LBlock revealed weaknesses in its key schedule, its designers presented a new version of the cipher with a revised key schedule. The attack presented in this paper does not exploit the structure of the key schedule or S-boxes used in the cipher. As a result, it is applicable to both variants of the LBlock as well as the block ciphers with analogous structures like TWINE. Moreover, we performed simulations on a small variant LBlock and present the first experimental results on the theoretical model of the multidimensional zero-correlation linear cryptanalysis method.     

Globally convergent limited memory bundle method for large-scale nonsmooth optimization

Many practical optimization problems involve nonsmooth (that is, not necessarily differentiable) functions of thousands of variables. In the paper [Haarala, Miettinen, Mäkelä, Optimization Methods and Software, 19, (2004), pp. 673–692] we have described an efficient method for large-scale nonsmooth optimization. In this paper, we introduce a new variant of this method and prove its global convergence for locally Lipschitz continuous objective functions, which are not necessarily differentiable or convex. In addition, we give some encouraging results from numerical experiments.     

Transition-Metal-Free Carbon Isotope Exchange of Phenyl Acetic Acids

A transition-metal-free carbon isotope exchange procedure on phenyl acetic acids is described. Utilizing the universal precursor CO₂, this protocol allows the carbon isotope to be inserted into the carboxylic acid position, with no need of precursor synthesis. This procedure enabled the labeling of 15 pharmaceuticals and was compatible with carbon isotopes [¹⁴C] and [¹³C]. A proof of concept with [¹¹C] was also obtained with low molar activity valuable for distribution studies.